rotary solenoid

Abstract

To provide a rotary solenoid the structure of which is relatively simple and can be produced at low cost, and in which substantially constant torque can be kept within a certain rotation range.SOLUTION: A rotary solenoid 10 has a configuration in which, with respect to the rotation axis of a rotor 20, a first virtual cylinder that matches a first inner circumferential surface 33 of a first core 30 and a second virtual cylinder that matches a second inner circumferential surface 38 of a second core 35 are separated from each other at a distance D in a back-to-back facing direction of the first virtual cylinder and the second virtual cylinder so that a torque fluctuation is suppressed while the range of a rotational angle is not narrowed so much. Accordingly, substantially constant torque can be kept within a certain rotation range without complicating the shape of the rotor 20 or the first core 30 or the second core 35.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rotary solenoid, and more particularly to a rotary solenoid that can maintain a substantially constant torque over a certain rotation range. [Background technology]

[0002] A rotary solenoid using a magnet has a core located near a rotatable rotor. A magnetic field is generated by energizing a coil, and the force acting between this magnetic field and the magnet is used to rotate the rotor. Such rotary solenoids are generally required to avoid sudden torque fluctuations within a predetermined rotation angle range and to stably obtain desired torque characteristics. To address this, a conventional solution has been to provide a stopper located considerably before the rotor reaches its full rotation angle, and to utilize torque within the range from the start of rotation until the stopper is abutted. However, this solution creates a new problem: the rotor's rotation angle range is narrowed. Therefore, various inventions have been developed to obtain desired torque characteristics without narrowing the rotation angle range.

[0003] Fig. 15 is a cross-sectional view showing a rotary solenoid according to the prior art. In Fig. 15, 90 is a rotary solenoid, 91 is a magnet rotor, 92 is a shaft, 93 is a magnet, 93a is an outer peripheral surface, 94 is a yoke, 94a is an inner peripheral surface, 95 is a yoke, 95b is an inner peripheral surface, 96a and 96b are restricting protrusions, 97a and 97b are air gap forming portions, 98a and 98b are gaps, and 99 is a coil.

[0004] FIG. 15 illustrates an invention disclosed in Japanese Patent Application Laid-Open Publication No. 2012-205343. The rotary solenoid 90 is a single-excitation rotary solenoid in which a magnet rotor 91 rotates when current is applied to a coil 99 and returns to its original position when current is stopped. The magnet rotor 91 includes a shaft 92 and a magnet 93 located at the midpoint of the shaft 92. The magnet 93 is cylindrical, with one radially facing south pole and the other facing north pole. The yokes 94 and 95 are formed of a sintered material or the like as rectangular blocks having a predetermined thickness and a curved arc shape along the circumferential direction. The yokes 94 and 95 also include cutout-shaped air gap-forming portions 97a and 97b, respectively, over a predetermined range on the inner circumferential surfaces 94a and 95b (which form the pole faces). The cutout-shaped air gap-forming portions 97a and 97b form a gap 98b wider than the gap 98a between the inner circumferential surfaces 94a and 95b and the outer circumferential surface 93a of the magnet 93. The range of the air gap forming portions 97a and 97b is set to be equal to or less than half the circumferential length of the inner circumferential surfaces 94a and 95b.

[0005] According to the above configuration, on the inner surfaces 94a and 95b of the yokes 94 and 95, the inner surfaces 94a and 95b and the magnet 93 are provided over a predetermined range from the rear end position in the rotation direction to the front.The yokes 94 and 95 are each provided with cutout-shaped air gap forming portions 97a and 97b that form a gap 98b wider than the gap 98a between the inner surfaces 94a and 95b and the outer surface 93a of the magnet 93 over a predetermined range on the inner surfaces 94a and 95b, which form magnetic pole surfaces.Therefore, even when a rotation range with a relatively large torque is set for the magnet rotor 91, even if the magnet rotor 91 is rotated by applying current and then the current is turned off, the magnetic force of the magnet 93 in the magnet rotor 91 is attracted to the narrow gap 98a rather than the wide gap 98b, so that the magnet rotor can be returned to the rotation start position by magnetic attraction alone. Therefore, since a return mechanism including a spring is no longer necessary, the problem of a significant drop in torque as the rotation end position is approached can be eliminated, and stable, good torque characteristics can be obtained. In addition, sufficient torque can be ensured from the start of rotation of the magnet rotor 91 when power is cut off, and the problem of a long time required to return to the rotation start position can also be eliminated.

[0006] However, with the above configuration, the shapes of the yokes 94 and 95 become complex, and high processing precision and assembly techniques are required because the gaps 98a and 98b must each be accurately formed to the specified widths when assembling the rotary solenoid 90. Therefore, it is difficult to adopt this configuration in markets where relatively inexpensive products are desired. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-205343 Summary of the Invention [Problem to be solved by the invention]

[0008] In order to solve the above-mentioned problems, the present invention aims to provide a rotary solenoid that has a structure that can be manufactured relatively simply and inexpensively and that can maintain a nearly constant torque within a certain rotation range. [Means for solving the problem]

[0009] The invention described in claim 1 is a rotary solenoid having a rotor made of a permanent magnet in part or in whole, formed in a cylindrical or columnar shape, and rotatable about a central axis of the outer circumferential surface as a rotation axis, and a first core and a second core disposed near the rotor and interposed between the rotor and the first core, wherein the first core has a first magnetic pole portion, faces the outer circumferential surface of the rotor, has a central axis parallel to the rotation axis of the rotor, and is spaced a predetermined distance from the central axis of the rotor. the second core has a second magnetic pole portion which faces the outer circumferential surface of the rotor, has a central axis parallel to the rotation axis of the rotor, and has a second inner circumferential surface which faces the outer circumferential surface of a second imaginary cylinder which is spaced a predetermined distance from the central axis of the rotor in a direction opposite to the central axis of the first imaginary cylinder.

[0010] Also, claim 1 The invention described in , omitted a cylindrical case, a coil bobbin disposed inside the case, and The rotary solenoid is characterized in that the first core and the second core are provided in a state where a portion of each of them is wrapped by the coil bobbin. The invention described in claim 1 is a rotary solenoid further comprising a shaft that is inserted into the rotor and has a through hole formed in a direction perpendicular to the central axis, and a fixing pin that is fixed by being pressed into the through hole of the shaft or by being inserted and glued, wherein the rotor has a first notch and a second notch formed at opposing positions on the base end of the shaft, and the portions near both ends of the fixing pin are pressed into or inserted into the first notch and the second notch, respectively.

[0011] Claim 2 The invention described in Claim 1In the invention described in the above, the first core further includes a first support portion formed integrally with the first magnetic pole portion at a circumferentially intermediate portion of the first magnetic pole portion, and the second core further includes a second support portion formed integrally with the second magnetic pole portion at a circumferentially intermediate portion of the second magnetic pole portion, and the first magnetic pole portion and the first support portion, as well as the second magnetic pole portion and the second support portion, are arranged in a state where a portion of them is wrapped by the coil bobbin.

[0013] Claim 3 The invention described in Claim 1 or 2 In the invention described above, the rotary solenoid is characterized in that the fixed pin is a spring pin or a parallel pin.

[0014] Claim 4 The invention described in Any one of claims 1 to 3 a base-end housing member formed in a substantially cylindrical shape and fixed by being press-fitted into an opening of the case on the base end side of the shaft; a tip-end housing member formed in a substantially cylindrical shape and fixed by being press-fitted into an opening of the case on the tip end side of the shaft; a base-end bearing that is fixed by having an outer ring inserted into the base-end housing member and that rotatably supports the shaft by having an inner ring inserted into the proximal portion of the shaft; and a tip-end bearing that is fixed by having an outer ring inserted into the tip-end housing member and that rotatably supports the shaft by having an inner ring inserted into the proximal portion of the shaft and, The rotary solenoid further comprises:

[0015] Claim 5 The invention described in Claim 4In the invention described above, the base end housing member has an annular groove formed on its inner circumferential surface closer to the base end of the shaft than the base end bearing, and the tip end housing member has an annular groove formed on its inner circumferential surface closer to the tip end of the shaft than the tip end bearing, and a base end C-type retaining ring is inserted into the annular groove of the base end housing member and prevents the base end bearing from coming off the base end housing member, and a tip end C-type retaining ring is inserted into the annular groove of the tip end housing member and prevents the tip end bearing from coming off the tip end housing member. and, The rotary solenoid further comprises:

[0016] Claim 6 The invention described in Claim 5 In the invention described in the item (1), a first coil and a second coil are formed by winding a coil wire around the coil bobbin. have The base end housing member has an outer annular protrusion formed on an end surface facing the coil bobbin so as to protrude in an annular shape, an inner annular protrusion provided inside the outer annular protrusion and formed so as to protrude in an annular shape, and a lead wire cutout portion formed by cutting out a part of the outer annular protrusion. and, a first lead wire connected to the first coil and wired in a gap between the outer circumferential annular protrusion and the inner circumferential annular protrusion of the base-end housing member; and a second lead wire connected to the second coil and wired in a gap between the outer circumferential annular protrusion and the inner circumferential annular protrusion of the base-end housing member. and, The rotary solenoid further comprises: [Effects of the Invention]

[0017] According to the invention described in claim 1, the first imaginary cylinder that coincides with the first inner surface of the first core and the second imaginary cylinder that coincides with the second inner surface of the second core are each spaced a predetermined distance from the rotor's rotation axis, and the first imaginary cylinder and the second imaginary cylinder are spaced back to back. This configuration suppresses torque changes without narrowing the range of rotation angle too much, so that a nearly constant torque can be maintained within a certain rotation range without making the rotor or core have a complex shape.

[0018] Also, claim 1 According to the invention described in the above, portions of the first core and second core are enclosed by the coil bobbin, i.e., the coil bobbin is formed by insert molding, which reduces the workload of precisely positioning the first core and second core when assembling the rotary solenoid, and enables reduction in the manufacturing costs of the rotary solenoid. Furthermore, the rotor and the shaft can be easily integrated by using a fixing pin.

[0019] Claim 2 According to the invention described in the above, by providing a first support portion and a second support portion on the coil bobbin, it becomes possible to hold the first support portion and the second support portion with a jig during insert molding, and the first core and the second core can be positioned even more accurately.

[0021] Claim 3 According to the invention described in (1), since a spring pin or a parallel pin is used, the fixing pin can be easily fixed to the rotor.

[0022] Claim 4 According to the invention described in the above, the base end housing member and the tip end housing member press-fitted into the case support the shaft via the base end bearing and the tip end bearing, so that the rotor fixed to the shaft can be positioned accurately.

[0023] Claim 5According to the invention described in (1), by providing a base end C-type retaining ring and a tip end C-type retaining ring, it is possible to prevent the base end bearing and the tip end bearing from moving outward due to external shock or vibration. Furthermore, if there is a problem with the operation of the base end bearing or the tip end bearing, the base end C-type retaining ring or the tip end C-type retaining ring can be removed, and then the base end bearing or the tip end bearing can be removed and replaced.

[0024] Claim 6 According to the invention described in (1), the first lead wire and the second lead wire can be prevented from being pinched between the base-end housing member and the coil bobbin. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is an explanatory diagram showing an outline of the basic structure of a rotary solenoid according to an embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of a rotary solenoid according to an embodiment of the present invention. [Figure 3] 1A, 1B, and 1C show a rotor of a rotary solenoid according to an embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a right side view. [Figure 4] 1A and 1B show a first core of a rotary solenoid according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a front view. [Figure 5] 1C is a cross-sectional view showing a first core of a rotary solenoid according to an embodiment of the present invention. FIG. [Figure 6] 1 is a plan view showing the arrangement of a first core and a second core of a rotary solenoid according to an embodiment of the present invention; [Figure 7] 1A, 1B, and 1C show a core-integrated coil bobbin of a rotary solenoid according to an embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a right side view. [Figure 8] 10A and 10B show a core-integrated coil bobbin of a rotary solenoid according to an embodiment of the present invention, where (d) is a cross-sectional view and (e) is a layout diagram of a first core and a second core. [Figure 9] 1A and 1B show a core-integrated coil bobbin of a rotary solenoid according to an embodiment of the present invention, in which (f) is a perspective view and (b) is a cross-sectional view showing the wiring configuration. [Figure 10] 1A and 1B show a shaft of a rotary solenoid according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a front view. [Figure 11] 1A, 1B, 1C, 1D, and 1E show a base end housing member of a rotary solenoid according to an embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a bottom view, FIG. 1C is a front view, and FIG. [Figure 12] 1A, 1B, 1C, 1D, and 1E show a front housing member of a rotary solenoid according to an embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a bottom view, FIG. 1C is a front view, and FIG. [Figure 13] 1A, 1B, and 1C show a case of a rotary solenoid according to an embodiment of the present invention, in which FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a cross-sectional view. [Figure 14] 5A and 5B show eccentric states in a rotary solenoid according to an embodiment of the present invention, where FIG. 5A is an explanatory diagram of eccentricity in the embodiment, and FIG. 5B is an explanatory diagram of another example of eccentricity. [Figure 15] FIG. 1 is a cross-sectional view showing a rotary solenoid according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0026] First, in all of the rotary solenoids according to the embodiments of the present invention described below, and in the claims, the term "distal side" refers to the distal end of the shaft, i.e., the end (and its vicinity) to which an external device mechanism is connected, and the term "base end" refers to the end (and its vicinity) opposite the distal end. Furthermore, the "center axis" of the shaft is the rotation axis of the rotary solenoid according to this embodiment, and this "center axis" also coincides with the central axes of the rotor, case, base end housing member, and distal end housing member. Therefore, in the following description and claims, when the term "rotation axis" of the shaft is used, it refers to the same central axis as the shaft, rotor, case, base end housing member, and distal end housing member.

[0027] Fig. 1 is an explanatory diagram showing an outline of the basic structure of a rotary solenoid according to an embodiment of the present invention. In Fig. 1, 20 is a rotor, 30 is a first core, 31a is a first magnetic pole portion, 31b is a second magnetic pole portion, 32 is a first support portion, 33 is a first inner circumferential surface, 35 is a second core, 36a is a second magnetic pole portion, 36b is a second magnetic pole portion, 37 is a second support portion, and 38 is a second inner circumferential surface. Fig. 2 is a cross-sectional view of the rotary solenoid according to an embodiment of the present invention. In FIG. 2, 10 is a rotary solenoid, 23 is a shaft, 24 is an intermediate portion, 25 is a tip-side protrusion, 26 is a base-side protrusion, 27 is a spring pin, 28 is a tip-side bearing, 28 is a base-side bearing, 40 is a core-integrated coil bobbin, 60 is a base-side housing member, 66 is a tip-side housing member, 70 is a case, 72 is a first coil, 73 is a second coil, 76a is a base-side C-type retaining ring, 76b is a tip-side C-type retaining ring, 77a is a base-side felt washer, 77b is a tip-side felt washer, 78a is a first lead wire, 78b is a second lead wire, 79 is a heat-shrinkable tube, and other symbols indicate the same as in FIG. 1.

[0028] First, an overview of a rotary solenoid 10 according to an embodiment of the present invention will be described. As shown in FIG. 2, the rotary solenoid 10 according to this embodiment has an outer shell formed by a case 70, a base-end housing member 60, and a tip-end housing member 66, and has an appearance that is close to a cylindrical shape. The tip of the tip-end protrusion 25 of the shaft 23 and its vicinity are connected to the mechanism of an external device and serve as a means for transmitting rotational motion. As described above, the central axis of the rotor 20 coincides with the central axis of the shaft 23, but when current is applied to the first coil 72 and the second coil 73, the rotor 20 rotates about the central axis common to the rotor 20 and the shaft 23.

[0029] 1 , the first core 30 includes first magnetic pole portions 31 a and 31 b, and the second core 35 includes second magnetic pole portions 36 a and 36 b. The first inner circumferential surfaces 33 of the first magnetic pole portions 31 a and 31 b are formed in a semi-cylindrical shape, and the central axes thereof are parallel to the rotation axes of the rotor 20 and the shaft 23. Similarly, the second inner circumferential surfaces 38 of the second magnetic pole portions 36 a and 36 b are also formed in a semi-cylindrical shape, and the central axes thereof are parallel to the rotation axes of the rotor 20 and the shaft 23. In addition, assuming a first imaginary cylinder coinciding with the first inner circumferential surface 33, this first imaginary cylinder is spaced a predetermined distance D from the rotation axes of the rotor 20 and the shaft 23. Furthermore, assuming a second imaginary cylinder that coincides with the second inner peripheral surface 38, this second imaginary cylinder is spaced a distance D from the rotation axis of the rotor 20 and the shaft 23 in a direction opposite to the central axis of the first imaginary cylinder. In other words, the central axes of the first imaginary cylinder and the second imaginary cylinder and the rotation axis of the rotor 20 and the shaft 23 are aligned on a straight line.

[0030] In this way, the rotary solenoid 10 according to this embodiment maintains a substantially constant torque within a certain rotation range by separating the central axes of the first and second imaginary cylinders from the rotation axis of the rotor 20 and shaft 23 by a distance D. Furthermore, the rotor 20 is formed in a substantially cylindrical shape, and the first inner circumferential surfaces 33 of the first magnetic pole portions 31 a and 31 b and the second inner circumferential surfaces 38 of the second magnetic pole portions 36 a and 36 b are formed in a semi-cylindrical shape, but the distances between the outer circumferential surface of the rotor 20 and the first inner circumferential surfaces 33 of the first magnetic pole portions 31 a and 31 b and the second inner circumferential surfaces 38 of the second magnetic pole portions 36 a and 36 b are always constant and do not change with rotation. Therefore, the rotary solenoid 10 according to this embodiment does not have a rotor or core with a complex shape, as in the invention described in JP 2014-229735 A. Also, unlike some oscillating solenoids, it does not have a configuration in which the distance between the opposing surfaces of the rotor and core changes as the rotor rotates.

[0031] Next, the structure of the rotary solenoid according to the embodiment and the shape and function of each component will be described in detail. Figure 3 shows the rotor of the rotary solenoid according to the embodiment of the present invention, with (a) being a plan view, (b) being a front view, and (c) being a right side view. In Figure 3, 21a is a first cutout portion, 21b is a second cutout portion, 22a is an outer peripheral surface, 22b is an inner peripheral surface, and other reference numerals indicate the same as in Figure 2.

[0032] As shown in FIG. 2, the rotor 20 is disposed in a space surrounded by the first magnetic pole portions 31a and 31b of the first core 30, the second magnetic pole portions 36a and 36b of the second core 35, and the core-integrated coil bobbin 40, and is integrally formed with the shaft 23, as described below. As shown in FIG. 3, the rotor 20 is formed by molding a magnet into a substantially cylindrical shape, and is magnetized so that the south pole and north pole are each substantially semi-cylindrical. The outer peripheral surface 22a faces the first magnetic pole portions 31a and 31b and the second magnetic pole portions 36a and 36b of the second core 35 with a small gap between them. The middle portion 24 of the shaft 23 is inserted into the inner peripheral surface 22b. The first cutout portion 21a and the second cutout portion 21b are formed for inserting a spring pin 27, which will be described later. The spring pin 27 may be press-fitted into the first cutout portion 21a and the second cutout portion 21b. After inserting or press-fitting the spring pin 27, an adhesive may also be used.

[0033] The shape of rotor 20 is not limited to the generally cylindrical shape shown in FIG. 3 . For example, the rotor may be composed of a first rotor member and a second rotor member made of permanent magnets and formed into a generally cylindrical shape with a sector-shaped cross section perpendicular to the central axis, with the sector-shaped outer peripheral surfaces of the first rotor member and the second rotor member arranged back-to-back to each other. In other words, the rotor according to the present invention can be formed into various shapes as long as it is formed into a cylindrical or columnar shape as a whole, has an outer peripheral surface that matches the outer peripheral surface 22a of rotor 20, and is magnetized in the same manner as rotor 20. Furthermore, a reinforcing member made of a nonmagnetic material and integrally formed with the permanent magnet member may be provided to reinforce the permanent magnet member.

[0034] Next, the first core 30 and the second core 35 will be described. FIG. 4 shows the first core of a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view and (b) being a front view. In FIG. 4, 32a denotes a first exposed surface, and the other reference numerals denote the same as those in FIG. 1. FIG. 5 shows the first core of a rotary solenoid according to an embodiment of the present invention, with (c) being a cross-sectional view. All reference numerals used in FIG. 5 denote the same as those in FIG. 1. In addition, FIG. 6 is a plan view showing the arrangement of the first core and the second core of a rotary solenoid according to an embodiment of the present invention. In FIG. 6, 37a denotes a second exposed surface, 80 denotes a gap, and the other reference numerals denote the same as those in FIGS. 1 and 4. Also shown is an eccentric state in a rotary solenoid according to an embodiment of the present invention, with (a) being an explanatory diagram of the eccentricity in the embodiment, and (b) being an explanatory diagram of another example of eccentricity. All reference numerals used in FIG. 14 denote the same as those in FIG. 1.

[0035] 4 and 5, the first core 30 has a first support portion 32 formed integrally with the first magnetic pole portions 31a and 31b at the circumferentially intermediate portion of the first magnetic pole portions 31a and 31b, which are formed in a substantially semi-cylindrical shape. When the core-integrated coil bobbin 40 is insert-molded, the first exposed surface 32a, which is the outer peripheral surface of the first support portion 32, is not covered with resin and is exposed to the outside. This is because, after assembly of the rotary solenoid 10, the first exposed surface 32a is configured to be in direct contact with or very close to the case 70, thereby reducing magnetic resistance between the first support portion 32 and the case 70 when current is applied to the first coil 72 and the second coil 73. 6, the second core 35 has second magnetic pole portions 36a and 36b and a second support portion 37 formed in exactly the same shapes as the first magnetic pole portions 31a and 31b and the first support portion 32 of the first core 30. In addition, the first core 30 and the second core 35 are arranged so that the first inner circumferential surface 33 and the second inner circumferential surface 38 face each other and are at the same position in the direction of the rotation axis of the shaft 23. Furthermore, in the second support portion 37 as well, in order to reduce the magnetic resistance between the second support portion 37 and the case 70, when the core-integrated coil bobbin 40 is insert-molded, a second exposed surface 37a, which is the outer circumferential surface, is not covered with resin and is exposed to the outside.

[0036] Furthermore, the first core 30 and the second core 35 are separated by a gap 80 to form independent magnetic poles. As described above, the central axis of the first imaginary cylinder and the central axis of the second imaginary cylinder are disposed at a distance D from the rotation axis of the shaft 23. Therefore, the gap 80 between the first magnetic pole portions 31a and 31b and the second magnetic pole portions 36a and 36b is 2D wider than the gap in the conventional configuration. Furthermore, the gap 80 is also required when forming the first coil 72 and the second coil 73, as described below. Note that the distance D is not limited to a specific length and can be slightly changed. While FIG. 14(a) shows the first core 30 and the second core 35 separated by the distance D, as in FIG. 1, it is also possible to offset the first core 30 and the second core 35 by a distance D' (>D), as shown in FIG. 14(b). Furthermore, the first inner peripheral surface 33 of the first core 30 and the second inner peripheral surface 38 of the second core 35 are formed in a semi-cylindrical shape, but slight modifications may be made, for example, by making only the edge portion and its surrounding area flat in order to obtain the required characteristics.

[0037] Next, the core-integrated coil bobbin 40 will be described. Fig. 7 shows a core-integrated coil bobbin for a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view, (b) being a front view, and (c) being a right side view. In Fig. 7, 41 is a base-side flat surface, 42a and 42b are openings, 43 is a base-side first inner partition plate, 44 is a base-side second inner partition plate, 45 is a tip-side flat surface, 46a and 46b are openings, 47 is a second side plate portion, 48 is a tip-side first inner partition plate, 49 is a tip-side second inner partition plate, 50 is a first outer-side partition plate, 51a is a first side portion, 51a is a second side portion, 52 is a second outer-side partition plate, 53a is a first side portion, 53a is a second side portion, and other reference numerals indicate the same elements as in Fig. 1. In addition, Fig. 8 shows a core-integrated coil bobbin of a rotary solenoid according to an embodiment of the present invention, where (d) is a cross-sectional view and (e) is a diagram showing the layout of the first and second cores. In Fig. 8, 54 is a first covering portion, 55 is a second covering portion, 56 is an intermediate portion, 57 is a first core opening, and 58 is a second core opening, and other reference numerals indicate the same as in Figs. 1 and 7. Furthermore, Fig. 9 shows a core-integrated coil bobbin of a rotary solenoid according to an embodiment of the present invention, where (f) is a perspective view and (b) is a cross-sectional view showing the wiring configuration. In Fig. 9, 74 is a coil wire, 75a is a first portion, 75b is a crossover portion, and 75c is a second portion, and other reference numerals indicate the same as in Figs. 1 and 7.

[0038] The core-integrated coil bobbin 40 is disposed inside the case 70 and between the base-end housing member 60 and the tip-end housing member. Furthermore, as described above, the core-integrated coil bobbin 40 is provided by insert molding so as to enclose a portion of the outer circumferential surfaces of the first core 30 and the second core 35. That is, as shown in FIG. 8 , the outer circumferential surfaces of the first magnetic pole portion 31 a of the first core 30 and the second magnetic pole portion 36 a of the second core 35 are enclosed in the first covering portion 54 of the core-integrated coil bobbin 40, and the outer circumferential surfaces of the first magnetic pole portion 31 b of the first core 30 and the second magnetic pole portion 36 b of the second core 35 are enclosed in the second covering portion 55. The outer circumferential surfaces of the first support portion 32 of the first core 30 and the second support portion 37 of the second core 35 are exposed to the outside at the first core opening 57 and the second core opening. Therefore, the first core 30 and the second core 35 are accurately positioned at predetermined positions in the intermediate portion 56 by the core-integrated coil bobbin 40 during the assembly process of the rotary solenoid 10, and continue to be held in the correct positions even after assembly.

[0039] As shown in Figures 7, 8(d) and 9(f), the core-integrated coil bobbin 40 is provided with a base-side first inner partition plate 43 formed in an approximately semi-cylindrical shape and located closer to the base-side protrusion 26 of the shaft 23 than the first core 30 and the second core 35, and a base-side second inner partition plate 44 formed in an approximately semi-cylindrical shape and located closer to the base-side protrusion 26 of the shaft 23 than the first core 30 and the second core 35, facing the base-side first inner partition plate 43. In addition, it is provided with a tip-side first inner partition plate 48 that is formed in an approximately semi-cylindrical shape and is provided closer to the tip-side protrusion 25 of the shaft 23 than the first core 30 and the second core 35, and a tip-side second inner partition plate 49 that is formed in an approximately semi-cylindrical shape and is provided closer to the tip of the shaft than the first core 30 and the second core 35, facing the tip-side first inner partition plate 48.

[0040] The core-integrated coil bobbin 40 also includes a first outer peripheral partition plate 50 formed in an approximately semi-cylindrical shape and arranged to cover the base end side first inner peripheral partition plate 43 and the tip end side first inner peripheral partition plate 48 from the outside, and a second outer peripheral partition plate 52 formed in an approximately semi-cylindrical shape and arranged to cover the base end side second inner peripheral partition plate 44 and the tip end side second inner peripheral partition plate 49 from the outside. Furthermore, as shown in Figure 9(g), a first portion 75a of the coil wire 74 is wound around the gap formed between the first side portion 51a and the second side portion 51b of the first outer peripheral partition plate 50 and the base end flat surface 41, and around the gap formed between the first side portion 53a and the second side portion 53b of the second outer peripheral partition plate 52 and the tip end flat surface 45. Similarly, as shown in Figure 9(g), a second portion 75c of the coil wire 74 is wound around the gap formed between the first side portion 53a and the second side portion 53b of the second outer peripheral partition plate 52 and the base end flat surface 41, and around the gap formed between the first side portion 53a and the second side portion 53b of the second outer peripheral partition plate 52 and the tip end flat surface 45, thereby forming a first coil 72 and a second coil 73. The first coil 72 and the second coil 73 have the same number of turns.

[0041] The first portion 75a of the wound coil wire 74 is held by the base-side first inner partition plate 43, the tip-side first inner partition plate 48, and the first outer partition plate 50, so that the shape of the second portion 75c does not collapse during or after winding. Similarly, the second portion 75c is held by the base-side second inner partition plate 44, the tip-side second inner partition plate 49, and the second outer partition plate 52. Furthermore, the first portion 75a and the second portion 75c of the coil wire 74 are continuous via the crossover portion 75b, so that the first coil 72 and the second coil 73 simultaneously generate magnetic fields when current is applied. The first core 30 and the second core 35, which have the same size and shape, are disposed in the intermediate portion 56 of the core-integrated coil bobbin 40, so that when current is applied to the first coil 72 and the second coil 73, the magnetic flux flowing through the first core 30 is the same as the magnetic flux flowing through the second core 35. In addition, the ends of the first coil 72 and the second coil 73 are connected to a first lead wire 78a and a second lead wire 78b, which are inserted through a heat-shrinkable tube 79 shown in FIG. 2.

[0042] Next, Fig. 10 shows a shaft of a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view and (b) being a front view. In Fig. 10, 23a denotes a through hole, and other reference numerals denote the same as those in Fig. 2. Fig. 11 shows a base-end housing member of a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view, (b) being a bottom view, (c) being a front view, and (d) being a cross-sectional view. In Fig. 11, 61 denotes an outer annular protrusion, 62 denotes an inner annular protrusion, 63 denotes a wiring groove, 64 denotes a lead wire notch, 65 denotes an inner circumferential surface, and 65a denotes an annular groove, and other reference numerals denote the same as those in Fig. 2. Fig. 12 shows a tip-end housing member of a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view, (b) being a bottom view, (c) being a front view, and (d) being a cross-sectional view. In Figure 12, 67 is a press-fit portion, 68 is an inner peripheral protrusion, 69 is an inner peripheral surface, 69a is an annular groove, and other symbols indicate the same as in Figure 2. Figure 13 shows a case of a rotary solenoid according to an embodiment of the present invention, with (a) being a plan view, (b) being a front view, and (c) being a cross-sectional view. In Figure 13, 71 is an inner peripheral surface, and other symbols indicate the same as in Figure 2.

[0043] The shaft 23 rotatably supports the rotor 20, and as shown in FIG. 10 , includes an intermediate portion 24, a tip-side protrusion 25 extending from the intermediate portion 24 toward the base end, and a base-side protrusion 26 extending from the intermediate portion 24 toward the base end. As shown in FIG. 2 , a spring pin 27 is press-fitted into the intermediate portion 24 with the rotor 20 inserted therethrough, and the rotor 20 is further fixed to the spring pin 27 with an adhesive. In addition, a tip-side bearing 28 is press-fitted into the tip-side protrusion 25, and a base-side bearing 29 is press-fitted into the base-side protrusion 26, and the shaft 23 is rotatably supported by the tip-side bearing 28 and the base-side bearing 29. Note that the shaft may be made up of two components, one on the base end side and one on the tip end side, and recesses may be formed in the base-end side surface and the other on the tip end side surface of the rotor, and the two components may be press-fitted into these recesses, respectively.

[0044] As shown in FIG. 11 , the base-end housing member 60 is formed in a substantially cylindrical shape. An outer annular protrusion 61 and an inner annular protrusion 62 are formed on the inner surface, i.e., the surface facing the tip-end housing member 66, and the gap between them serves as a wiring groove 63. The provision of the wiring groove 63 prevents the first lead wire 78a and the second lead wire 78b from being pinched between the base-end housing member 60 and the core-integrated coil bobbin 40. Furthermore, the first lead wire 78a and the second lead wire 78b from contacting the shaft 23 and the like. The wiring groove 63 also has a lead wire cutout 64 formed therein for guiding the first lead wire 78a and the second lead wire 78b to the outside. A step is formed on the inner circumferential surface 65 to determine the press-fit depth of the base-end bearing 29. Furthermore, the base-end bearing 29 can be press-fitted or removed from the outside of the hollow portion, making it replaceable if there is a problem with the base-end bearing 29. Additionally, an annular groove 65a is formed in the inner circumferential surface 65. The annular groove 65a is formed for inserting a base-end C-type retaining ring 76a. As shown in FIG. 2, the base-end C-type retaining ring 76a serves to prevent the base-end bearing 29 from being removed from the base-end housing member 60. Furthermore, the opening on the outside of the base-end housing member 60 is closed by a base-end felt washer 77a.

[0045] As shown in FIG. 12, the tip-side housing member 66 is formed in a substantially cylindrical shape, and an annular groove 69a is formed in the inner circumferential surface 69. The annular groove 69a is formed to allow insertion of a tip-side C-shaped retaining ring 76b. As shown in FIG. 2, the tip-side C-shaped retaining ring 76b serves to prevent the base-end bearing 29 from coming off the tip-side housing member 66. In addition, the outer opening of the tip-side housing member 66 is closed by a base-end felt washer 77b. As shown in FIGS. 2 and 13, the case 70 is formed in a substantially cylindrical shape, and the base-end housing member 60 and the tip-side housing member 66 are press-fitted into both ends of the inner circumferential surface 71.

[0046] As described above, the rotary solenoid 10 according to the embodiment of the present invention is configured such that the first imaginary cylinder, which coincides with the first inner circumferential surface 33 of the first core 30, and the second imaginary cylinder, which coincides with the second inner circumferential surface 38 of the second core 35, are spaced apart by a distance D from the rotation axis of the rotor 20 in a direction in which the first imaginary cylinder and the second imaginary cylinder face each other, thereby suppressing changes in torque without significantly reducing the range of the rotation angle. This makes it possible to maintain a substantially constant torque over a certain rotation range without giving the rotor 20, the first core 30, or the second core 35 a complex shape, as in the invention of JP 2014-229735 A. In addition, there is no need for a complex arrangement in which the distance between the rotor and the core changes as the rotor rotates. Also, portions of the first core 30 and the second core 35 are enclosed by the core-integrated coil bobbin 40, that is, the core-integrated coil bobbin 40 is formed by insert molding, which reduces the workload of precisely positioning the first core 30 and the second core 35 when assembling the rotary solenoid 10 and makes it possible to reduce the manufacturing cost of the rotary solenoid 10. Furthermore, by providing the coil bobbin with the first support portion and the second support portion, it becomes possible to hold the first support portion and the second support portion with a jig during insert molding, allowing for even more precise positioning of the first core and the second core.

[0047] In addition, the rotor 20 and shaft 23 are integrated using the spring pin 27, which serves as a fixing pin, so that the rotor 20 and shaft 23 can be easily integrated. Furthermore, in the rotary solenoid 10 according to the embodiment of the present invention, the base end housing member 60 and the tip end housing member 66, which are press-fitted into the case 70, support the shaft 23 via the base end bearing 29 and the tip end bearing 28, so that the rotor 20, which is fixed to the intermediate portion 24 of the shaft 23, can be accurately positioned. Furthermore, the provision of the base end C-type retaining ring 76a and the tip end C-type retaining ring 76b prevents the base end bearing 29 and the tip end bearing 28 from moving outward due to external shock or vibration. Furthermore, if there is a problem with the operation of the base end bearing or the tip end bearing 28, the base end C-type retaining ring 76a or the tip end C-type retaining ring 76b can be removed and replaced. In addition, since the wiring groove 63 is provided in the base end housing member 60, the first lead wire 78a and the second lead wire 78b can be prevented from being pinched between the base end housing member 60 and the core-integrated coil bobbin 40.

[0048] The present invention is not limited to the configuration of the embodiments described above, and can be applied to various rotary solenoids as long as it does not deviate from the scope of the claims, such as, for example, as described above, the rotor can be composed of a first rotor member and a second rotor member made of permanent magnets and formed in an approximately cylindrical shape with a sector-shaped cross section perpendicular to the central axis, and the sector-shaped outer surfaces of the first rotor member and the second rotor member can be arranged back to back to form a rotor. [Explanation of symbols]

[0049] 10 Rotary Solenoid 20 rotors 21a First notch 21b Second notch 22a Outer surface 22b Inner surface 23 Shaft 23a Through hole 24 Middle section 25 Tip side protrusion 26 Proximal protrusion 27 Spring pin 28 Tip bearing 29 Base end bearing 30 First Core 31a First magnetic pole part 31b Second magnetic pole part 32 First support part 32a First exposed surface 33 first inner peripheral surface 35 Second Core 36a Second magnetic pole part 36b Second magnetic pole part 37 Second support 37a Second exposed surface 38 Second inner surface 40 Core integrated coil bobbin 41 Proximal flat surface 42a opening 42b opening 43 base end side first inner peripheral side partition plate 44 Base end side second inner peripheral side partition plate 45 Tip side flat surface 46a opening 46b opening 47 Second side panel 48 First inner peripheral partition plate on the tip side 49 Second inner peripheral partition plate on the tip side 50 First outer peripheral partition plate 51a First side portion 51b Second side part 52 Second outer peripheral partition plate 53a First side part 53b Second side part 54 First covering part 55 Second covering part 56 Middle section 57 First core opening 58 Second core opening 60 base end housing member 61 Outer circumferential protrusion 62 Inner annular protrusion 63 Wiring groove 64 Lead wire cutout 65 Inner surface 65a Annular groove 66 Tip side housing member 67 Press-fit section 68 Inner protrusion 69 Inner surface 69a Annular groove 70 cases 71 Inner peripheral surface 72 First Coil 73 Second Coil 74 Coil Wire 75a First Part 75b Crossover section 75c Second Part 76a Base end C-type retaining ring 76b Tip side C-type retaining ring 77a Base end felt washer 77b Tip felt washer 78a First Lead 78b Second Lead 79 Heat shrink tubing 80 gap 90 Rotary solenoid 91 Magnet rotor 92 Shaft 93 Magnet 93a Outer surface 94 York 94a Inner surface 95 York 95b Inner surface 96a Restriction convex part 96b Restriction convex part 97a Air gap forming part 97b Air gap forming section 98a Gap 98b Gap 98c Gap 99 Coil

Claims

1. a rotor that is made entirely or partially of permanent magnets, that is formed in a cylindrical or columnar shape, and that is rotatable about a central axis of the outer circumferential surface; a first core and a second core arranged near the rotor with the rotor interposed therebetween; A rotary solenoid having the first core has a first magnetic pole portion, and a first inner peripheral surface is formed on the first magnetic pole portion, the first inner peripheral surface facing the outer peripheral surface of the rotor, the central axis of which is parallel to the rotational axis of the rotor, and which is spaced a predetermined distance from the rotational axis of the rotor, and the first inner peripheral surface is aligned in part or entirely with the outer peripheral surface of a first imaginary cylinder; the second core has a second magnetic pole portion, and a second inner peripheral surface is formed which faces the outer peripheral surface of the rotor, has a central axis parallel to the rotational axis of the rotor, and is spaced a predetermined distance from the rotational axis of the rotor in a direction opposite to the central axis of the first imaginary cylinder, and which partially or entirely coincides with the outer peripheral surface of a second imaginary cylinder; a case formed in a substantially cylindrical shape; a coil bobbin disposed inside the case; and the first core and the second core are provided in a state where a portion of each of the first core and the second core is wrapped by the coil bobbin, a shaft that is inserted into the rotor and has a through hole formed in a direction perpendicular to the central axis; a fixing pin fixed by being press-fitted into the through hole of the shaft or by being inserted and then adhered; and The rotor is a rotary solenoid characterized in that a first notch and a second notch are formed at opposing positions on the base end of the shaft, and the portions of the fixing pin near both ends are press-fitted or inserted into the first notch and the second notch, respectively.

2. the first core further includes a first support portion formed integrally with the first magnetic pole portion at a circumferentially intermediate portion of the first magnetic pole portion, the second core further includes a second support portion formed integrally with the second magnetic pole portion at a circumferentially intermediate portion of the second magnetic pole portion, 2. The rotary solenoid according to claim 1, wherein the first magnetic pole portion and the first support portion, and the second magnetic pole portion and the second support portion are partially enclosed by the coil bobbin.

3. 3. The rotary solenoid according to claim 1, wherein the fixed pin is a spring pin or a parallel pin.

4. a base-end housing member formed in a substantially cylindrical shape and fixed by being press-fitted into an opening of the case on a base-end side of the shaft; a tip-side housing member formed in a substantially cylindrical shape and fixed by being press-fitted into an opening of the case on the tip side of the shaft; a base-end side bearing having an outer ring inserted into the base-end side housing member to be fixed, and an inner ring inserted into the base-end side bearing to rotatably support the shaft in the vicinity of the base end of the shaft; a tip-side bearing having an outer ring inserted into the tip-side housing member to fix the shaft, and an inner ring inserted into the tip-side housing member to rotatably support the shaft; 4. The rotary solenoid according to claim 1, further comprising:

5. the base-end housing member has an annular groove formed on an inner circumferential surface thereof closer to the base end of the shaft than the base-end bearing; the tip-side housing member has an annular groove formed on an inner circumferential surface thereof closer to the tip of the shaft than the tip-side bearing, a base-end C-type retaining ring that is inserted into the annular groove of the base-end housing member and that prevents the base-end bearing from coming off the base-end housing member; a tip-side C-shaped retaining ring that is inserted into the annular groove of the tip-side housing member and that prevents the tip-side bearing from coming off the tip-side housing member; 5. The rotary solenoid of claim 4, further comprising:

6. a first coil and a second coil formed by winding a coil wire around the coil bobbin; the base-end housing member includes an outer-circumferential annular protrusion formed on an end face facing the coil bobbin so as to protrude in an annular shape, an inner-circumferential annular protrusion provided more inward than the outer-circumferential annular protrusion and formed so as to protrude in an annular shape, and a lead wire cutout portion formed by cutting out a portion of the outer-circumferential annular protrusion, a first lead wire connected to the first coil and wired in a gap between the outer circumferential annular protrusion and the inner circumferential annular protrusion of the base-end housing member; a second lead wire connected to the second coil and wired in a gap between the outer circumferential annular protrusion and the inner circumferential annular protrusion of the base-end housing member; 6. The rotary solenoid of claim 5, further comprising:

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