Actuator

Abstract

An actuator 17 comprises: a case 24; a rod 26 which is accommodated in the case 24 and has a tip end that projects from an opening 34c to the outside of the case 24; a motor 28 accommodated in the case 24; and a movement mechanism 32 which is accommodated in the case 24 and is driven by the motor 28 to move the rod 26 in the axial direction thereof. The movement mechanism 32 includes an annular member into which a rod 26 is inserted, wherein: the rod 26 has a male screw portion 26g on an outer circumference thereof; the annular member has a female screw portion 42e on an inner circumference thereof; the rod 26 moves in the axial direction in response to rotation of the annular member; the case 24 has a regulating portion 34d on the side of the annular member, in the axial direction, on which the tip end is located; the rod 26 has a notched portion 26m that extends in the axial direction in a portion of the circumferential direction; and radial displacement in a radial direction is regulated by the notched portion 26m coming into contact with the regulating portion 34d.

Description

Actuator

[0001] The present disclosure relates to actuators.

[0002] (1) (2) Patent Document 1 discloses a vehicle lamp that can perform aiming adjustment, which is an initial adjustment of the misalignment of the optical axis of the lamp unit, and adjustment of the misalignment of the optical axis of the lamp unit that changes depending on the weight of an object mounted on the vehicle. This vehicle lamp allows the misalignment of the optical axis of the lamp unit to be adjusted.

[0003] (3) Patent Document 1 discloses an actuator for adjusting the misalignment of the optical axis of a lamp unit. This actuator includes a case, a rod, and a movement mechanism. The movement mechanism includes an annular member through which the rod is inserted. The rod has a male thread on its outer periphery, and the annular member has a female thread on its inner periphery that screws into the male thread, and the rod moves in the axial direction as the annular member rotates.

[0004] Japanese Patent Application Laid-Open No. 2019-123508

[0005] (1) The present disclosure has been made in light of the above circumstances, and one exemplary purpose of one aspect thereof is to provide a technology that is relatively easy to manufacture, with respect to a structure that suppresses large rattles in an actuator rod.

[0006] (2) In Patent Document 1, leveling adjustment is performed automatically using an actuator, but aiming adjustment is performed manually by an operator by rotating an aiming screw. In contrast, there is a demand for automatic aiming adjustment using an actuator. In this case, it is necessary to increase the stroke of the actuator rod.

[0007] The present disclosure has been made in light of the above circumstances, and one exemplary purpose of an embodiment thereof is to provide an actuator that achieves a long stroke.

[0008] (3) The present disclosure has been made in light of the above circumstances, and one exemplary purpose of an embodiment thereof is to provide an actuator that can reduce or eliminate undercut portions in a rod.

[0009] (1) An actuator according to one aspect of the present disclosure includes a case having an opening, a rod housed within the case with a tip protruding from the opening to the outside of the case, a motor housed within the case, and a movement mechanism housed within the case and driven by the motor to move the rod in its axial direction. The movement mechanism includes an annular member through which the rod is inserted. The annular member is restricted in its axial movement, the rod has a male threaded portion on its outer periphery, and the annular member has a female threaded portion on its inner periphery that meshes with the male threaded portion, the rod moves in the axial direction in response to rotation of the annular member, and the case has a restricting portion on the axial side where the tip is located relative to the annular member. The rod has a notch extending in the axial direction in a portion of its circumferential direction, and radial displacement is restricted by the notch coming into contact with the restricting portion.

[0010] (2) An actuator according to one aspect of the present disclosure includes a case having an opening, a rod housed in the case with a tip protruding from the opening to the outside of the case, a motor housed in the case, and a movement mechanism housed in the case and driven by the motor to move the rod in its axial direction. The movement mechanism includes an annular member through which the rod is inserted. The annular member is restricted from moving in the axial direction, the rod has a male threaded portion on its outer periphery, and the annular member has a female threaded portion on its inner periphery that screws into the male threaded portion. The rod moves in the axial direction as the annular member rotates, and a portion of the male threaded portion is exposed from the annular member.

[0011] (3) An actuator according to one aspect of the present disclosure includes a case having an opening, a rod housed in the case with a tip protruding from the opening to the outside of the case, a motor housed in the case, and a movement mechanism housed in the case and driven by the motor to move the rod in its axial direction. The movement mechanism includes an annular member through which the rod is inserted. The annular member is restricted from moving in the axial direction, the rod has a male threaded portion on its outer periphery, and the annular member has a female threaded portion on its inner periphery that threads with the male threaded portion, the rod moves in the axial direction in response to rotation of the annular member, and the rod is made of resin and has a notch extending in the axial direction along a portion of its circumference.

[0012] (1) According to an embodiment of the first aspect of the present disclosure, it is possible to provide a technology that is relatively easy to manufacture with respect to a structure that suppresses large rattles in the rod of the actuator. Alternatively, (2) according to an embodiment of the second aspect of the present disclosure, it is possible to provide an actuator that achieves a long stroke. Alternatively, (3) according to an embodiment of the third aspect of the present disclosure, it is possible to provide an actuator that can reduce or eliminate undercut portions in the rod.

[0013] 1. A cross-sectional view of a vehicle lamp including an actuator according to an embodiment. Figures 2(a) and (b) are side views illustrating the operation of the actuator of Figure 1. A perspective view of the actuator of Figure 1. A front view of the actuator of Figure 1. A side view of the actuator of Figure 1. A side view of the actuator of Figure 1. A view showing an enlarged view of a cylindrical protrusion and its periphery in Figure 6. A perspective view of the actuator of Figure 1. A perspective sectional view of the actuator of Figure 1. A perspective view of the actuator of Figure 1. A side view of an actuator according to a second embodiment. A perspective view of the actuator of Figure 11. A perspective view of an enlarged view of a cylindrical protrusion and its periphery of the actuator of Figure 11. A cross-sectional view of the actuator of Figure 11. A side view of the rod of Figure 11. A perspective sectional view of the rod of Figure 11.

[0014] The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0015] (First embodiment) Please refer to Figure 1. The vehicle lamp 1 is a headlamp of the vehicle. The vehicle lamp 1 is disposed on each of the left and right sides of the front of the vehicle body. The two vehicle lamps 1 disposed on the left and right are configured substantially identically.

[0016] The vehicle lamp 1 comprises a lamp body 2 having an opening on the front side of the lamp, a translucent outer cover 4 attached to the lamp body 2 so as to cover the opening of the lamp body 2, and a lamp unit 10 provided within a lamp chamber 3 formed by the lamp body 2 and the outer cover 4.

[0017] The lamp unit 10 includes a heat sink 11 , a light source unit 12 , a lens holder 13 , a projection lens 14 , a support member 16 , and an actuator 17 .

[0018] The heat sink 11 fits into an opening 2a formed in the rear surface of the lamp body 2. The heat sink 11 is exposed to the outside through the opening 2a.

[0019] The support member 16 is fixed to the heat sink 11. The support member 16 can also be considered as part of the heat sink 11. The support member 16 may be fixed to the lamp body 2.

[0020] The light source unit 12 includes a light source (not shown) and a reflector 22. The light source is disposed inside the reflector 22 so as to face a reflective surface (not shown) of the reflector 22. The reflector 22 and the light source are fixed to the support member 16.

[0021] The projection lens 14 is a plano-convex aspherical lens with a convex surface on the front side of the lamp and a flat surface on the rear side of the lamp. Light emitted from the light source is reflected toward the front of the lamp by the reflective surface of the reflector 22, and at least a portion of the light passes through the projection lens 14. The light that passes through the projection lens 14 illuminates the area in front of the lamp through the outer cover 4.

[0022] The lens holder 13 is disposed on the front side of the lamp of the reflector 22. The lens holder 13 includes a lens holding portion 13a. The lens holding portion 13a is an annular frame, and the projection lens 14 is fixed to the front surface of the lens holding portion 13a. A joint member 15 is fixed to a lower portion 13c of the lens holder 13.

[0023] The actuator 17 is a mechanism for performing both aiming adjustment, which is an initial adjustment of the misalignment of the optical axis of the lamp unit 10, and leveling adjustment, which adjusts the misalignment of the optical axis of the lamp unit 10 that changes due to the weight of on-vehicle objects. The actuator 17 is located on the rear side of the lamp of the lens holder 13, below the support member 16.

[0024] The actuator 17 includes a case 24 and a rod 26. The actuator 17 is disposed so that the tip of the rod 26 faces the front of the lamp and extends in the longitudinal direction of the lamp. The tip of the rod 26 is connected to the joint member 15. A drive circuit (not shown) provided within the case 24 receives a control signal from a control unit (not shown) provided outside the lamp unit 10. In response to the control signal, the rod 26 moves in the longitudinal direction of the lamp relative to the case 24 and, ultimately, the lamp body 2.

[0025] Referring to Figure 2, in Figure 2(b), the rod 26 is positioned further rearward of the lamp than in Figure 2(a). When the rod 26 moves from the position in Figure 2(a) to the position in Figure 2(b), i.e., moves rearward of the lamp, the lower portion 13c of the lens holder 13 is pulled rearward of the lamp via the joint member 15, causing the lens holder 13 and, ultimately, the projection lens 14 supported by the lens holder 13 to rotate counterclockwise in Figure 2 about the support shaft 13b, and the optical axis Ax of the projection lens 14 tilts further downward.

[0026] When the rod 26 moves from the position in Figure 2(b) to the position in Figure 2(a), i.e., moves toward the front of the lamp, the lower part 13c of the lens holder 13 is pushed toward the front of the lamp via the joint member 15, causing the lens holder 13 and therefore the projection lens 14 supported by the lens holder 13 to rotate clockwise in Figure 2 around the support shaft 13b, and the optical axis Ax of the projection lens 14 to tilt further upward.

[0027] That is, by moving the rod 26 of the actuator 17 in the front-rear direction, the optical axis Ax can be displaced in the up-down direction.

[0028] The above is the overall configuration of the vehicle lamp 1. Next, the actuator 17 will be described in detail.

[0029] Please refer to Figures 3 to 10. Figures 6 and 7 show cross sections of the case 24 and the worm wheel 42. Figure 8 shows a cross section of the case 24. Figure 9 is a cross section of the actuator 17 taken along line A-A in Figure 5. Figures 6 to 8 omit the illustration of the substrate 30. Figure 10 omits the illustration of the case 24.

[0030] In order to explain the positional relationship between the components, "upper," "lower," "front," "rear," "left," and "right" are defined as shown in the figure, but these are for convenience of explanation and do not limit the orientation in which the actuator 17 is used; the actuator 17 can be used in any orientation. As will be described later, the front-to-rear direction coincides with the extension direction of the rod 26, and therefore the front-to-rear direction is also referred to as the axial direction. The circumferential direction of a circle centered on the axial direction of the rod 26 is referred to as the circumferential direction, and the radial direction of that circle is referred to as the radial direction.

[0031] The actuator 17 includes a case 24, a rod 26, a motor 28, a substrate 30, and a movement mechanism 32. The case 24 is formed in a box shape. The rod 26, the motor 28, the substrate 30, and the movement mechanism 32 are housed within the case 24. A spherical portion 26e at the tip of the rod 26 protrudes outside the case 24 through an opening 34c.

[0032] The case 24 includes a first case portion 34 and a second case portion 36. The second case portion 36 is disposed rearward of the first case portion 34. That is, the first case portion 34 and the second case portion 36 face each other in the front-to-rear direction. The first case portion 34 and the second case portion 36 are both made of resin and formed by injection molding.

[0033] The first case portion 34 is formed in a box shape with an opening on the back side, and the second case portion 36 is formed in a box shape with an opening on the front side, and the first case portion 34 and the second case portion 36 are connected so that their openings meet.

[0034] The first case portion 34 has a cylindrical protrusion 34b that protrudes forward from the upper portion of the front surface 34a thereof. An opening 34c is formed at the front end of the cylindrical protrusion 34b.

[0035] The cylindrical protrusion 34b has a restricting portion 34d. The restricting portion 34d faces the rod 26 in the radial direction with a small gap (for example, about 0.5 mm) between them. The restricting portion 34d has an inner circumferential surface 34j that corresponds to a part of a cylindrical surface. When the rod 26 is displaced in the radial direction, the rod 26 comes into contact with the inner circumferential surface 34j of the restricting portion 34d. In other words, the rod 26's contact with the inner circumferential surface 34j of the restricting portion 34d restricts radial displacement. This makes it possible to suppress significant rattle of the rod 26.

[0036] The restricting portion 34d may be formed intermittently in the circumferential direction as shown in the figure, or may be formed continuously in the circumferential direction, i.e., in a ring shape. The restricting portion 34d has chamfered edges 34e, 34f in the front-rear direction. A chamfered shape means a shape in which sharp corners have been cut off. The edges 34e, 34f may have a C-chamfered shape as shown in the figure, an R-chamfered shape, or other chamfered shapes. The chamfered shape may be achieved by chamfering, or may be formed into that shape in advance by injection molding.

[0037] The rod 26 is made of resin and formed by injection molding. The rod 26 is hollow to prevent sink marks. The rod 26 includes a tip end 26 a, a base end 26 c, an intermediate portion 26 b located between the tip end 26 a and the base end 26 c, and two arms 26 d extending rearward from the outer circumferential surface of the base end 26 c.

[0038] The tip portion 26a includes a spherical portion 26e provided at the tip and a constricted portion 26f provided between the spherical portion 26e and the intermediate portion 26b. The spherical portion 26e is rotatably held by the joint member 15. In other words, the spherical portion 26e is always positioned outside the case 24.

[0039] The intermediate portion 26b has, on its outer periphery, a male thread portion 26g that screws into a female thread portion 42e of a worm wheel 42 (described later). The male thread portion 26g is formed relatively long in the axial direction, and is formed axially longer than not only the female thread portion 42e of the worm wheel 42 but also the worm wheel 42 itself. Therefore, a portion of the male thread portion 26g in the axial direction is always exposed from the worm wheel 42 without being surrounded by the worm wheel 42. The front side of the male thread portion 26g may protrude outside the case 24 through the opening 34c as shown. The male thread portion 26g may also be formed over the entire intermediate portion 26b in the axial direction.

[0040] The male thread portion 26g has chamfered edges 26s1, 26s2 at both front and rear ends of the thread portion 26s. The edges 26s1, 26s2 may have a rounded chamfered shape as shown in the figure, a C-chamfered shape, or any other chamfered shape.

[0041] The base end portion 26c is always located inside the case 24. The base end portion 26c is not surrounded by the worm wheel 42 and is always located behind the worm wheel 42.

[0042] The left arm 26d_l is provided on the left side of the base end 26c. The left arm 26d_l includes a root portion 26h_l that protrudes leftward from the base end 26c, and an extending portion 26i_l that extends from the root portion 26h_l rearward beyond the base end 26c. A rear end 26j_l of the extending portion 26i_l is always located within the second case portion 36.

[0043] The right arm 26d_r is provided to the right of the base end portion 26c. The right arm 26d_r includes a root portion 26h_r that protrudes to the right from the base end portion 26c, and an extension portion 26i_r that extends from the root portion 26h_r rearward of the base end portion 26c. A rear end 26j_r of the extension portion 26i_r is always located within the second case portion 36.

[0044] The extension portions 26i_l, 26i_r engage with the engagement portions 36a_l, 36a_r of the second case portion 36, respectively, throughout the entire stroke range of the rod 26. This restricts rotation of the rod 26. The engagement portions 36a_l, 36a_r may be grooves extending in the front-rear direction and formed on the left and right inner wall surfaces of the second case portion 36. In this case, the extension portions 26i_l, 26i_r slide within the grooves serving as the engagement portions 36a_l, 36a_r, respectively. In particular, the rear ends 26j_l, 26j_r of the extension portions 26i_l, 26i_r are positioned within the grooves serving as the engagement portions 36a_l, 36a_r throughout the entire stroke range of the rod 26. Meanwhile, the extension portions 26i_l, 26i_r do not engage with or contact the first case portion 34 throughout the entire stroke range of the rod 26.

[0045] The motor 28 is, for example, a DC motor. The motor 28 has a rotation shaft 28a extending vertically and held in the case 24 with the tip of the rotation shaft 28a facing upward. The motor 28 drives a movement mechanism 32 to move the rod 26 in its axial direction.

[0046] The movement mechanism 32 includes a worm 38, a transmission gear 40, and a worm wheel 42. The worm 38 is coaxially fixed to the rotation shaft 28a of the motor 28. In other words, the worm 38 is disposed inside the case 24 so that its rotation shaft extends in the vertical direction, and rotates integrally with the rotation shaft 28a of the motor 28.

[0047] The transmission gear 40 is rotatably supported by the case 24. The transmission gear 40 transmits the rotation of the worm 38, i.e., the rotation shaft 28a of the motor 28, to the worm wheel 42. More specifically, the transmission gear 40 has a worm wheel portion 40a and a worm portion 40b. The worm wheel portion 40a and the worm portion 40b are provided coaxially. The worm wheel portion 40a meshes with the worm 38. The worm portion 40b meshes with the worm wheel 42. The worm wheel portion 40a and the worm portion 40b are formed integrally and rotate simultaneously.

[0048] The worm wheel 42 is made of resin and formed by injection molding. The worm wheel 42 is an annular member through which the rod 26 is inserted. The worm wheel 42 surrounds a portion of the rod 26 in the axial direction. A front portion 42a of the worm wheel 42 is surrounded by the cylindrical protrusion 34b of the first case portion 34.

[0049] The movement of the worm wheel 42 in the front-rear direction is restricted by the case 24. An engaging portion 42d formed on the outer peripheral surface of the front portion 42a of the worm wheel 42 engages with an engaging portion 34h formed on the inner peripheral surface of the cylindrical protrusion 34b of the first case portion 34, thereby restricting the movement of the worm wheel 42 in the front-rear direction. For example, as shown in the figure, the engaging portion 42d of the worm wheel 42 may be a recess, and the engaging portion 34h of the cylindrical protrusion 34b of the first case portion 34 may be a protrusion that fits into the recess.

[0050] The worm wheel 42 has a female thread portion 42e on its inner periphery. The female thread portion 42e is threadedly engaged with the male thread portion 26g of the rod 26. The female thread portion 42e is formed on only a portion of the worm wheel 42 in the axial direction, although this is not limited to this. This allows the female thread portion 42e to be shortened in the axial direction. The inner diameter of the non-female thread portion 42f is formed to be larger than the outer diameter of the rod 26 so as not to interfere with the rod 26. For example, the inner diameter of the non-female thread portion 42f is equal to or larger than the root diameter of the female thread portion 42e.

[0051] The female thread portion 42e may be formed only on the rear portion 42b of the worm wheel 42. In this case, the female thread portion 42e may be formed on the entire rear portion 42b as shown in the figure, or may be formed on only a portion of the rear portion 42b in the axial direction. The female thread portion 42e may also be formed only on the front portion 42a. In this case, the female thread portion 42e may be formed on the entire front portion 42a, or may be formed on only a portion of the front portion 42a in the axial direction. The female thread portion 42e may also be formed to straddle both the front portion 42a and the rear portion 42b. In this case, the female thread portion 42e may be formed on the entire front portion 42a and a portion of the rear portion 42b in the axial direction, or on a portion of the front portion 42a in the axial direction and the entire rear portion 42b, or on a portion of the front portion 42a in the axial direction and a portion of the rear portion 42b in the axial direction.

[0052] The board 30 is housed within and held by the case 24. Although not particularly limited, the board 30 is held at the right end of the case 24 with the mounting surface 30a facing left. A motor drive circuit 46 including terminals and electronic components (not shown) and a potentiometer 44 is mounted on the mounting surface 30a. The terminals are connected to terminals of the motor 28. The electronic components are, for example, an IC or a surge absorber. The motor 28 is electrically connected to the motor drive circuit 46 and is driven by the motor drive circuit 46.

[0053] When the motor 28 is driven and the rotating shaft 28a of the motor 28 rotates, the worm wheel 42 rotates accordingly. Depending on the direction and amount of rotation, the threaded engagement between the female thread portion 42e of the worm wheel 42 and the male thread portion 26g of the rod 26 changes, and the rod 26 moves along its axial direction.

[0054] A joint member 26k is connected to the base end 26c of the rod 26. The joint member 26k is engaged with a rod 44a of a potentiometer 44. The position of the rod 44a changes as the rod 26 moves forward and backward. The motor drive circuit can recognize the position of the rod 26 based on the position of the rod 44a.

[0055] Next, the effects of the embodiment will be described. A portion of the male threaded portion 26g of the rod 26 in the axial direction is not surrounded by the worm wheel 42 and is exposed from the worm wheel 42. In other words, the male threaded portion 26g of the rod 26 is formed relatively long in the axial direction. This makes it possible to achieve a longer stroke of the rod 26 while maintaining the length of the rod 26, and therefore the dimensions of the actuator 17, at approximately the same level as in the conventional embodiment.

[0056] Furthermore, in this embodiment, the rod 26 has a long stroke by forming the male threaded portion 26g of the rod 26 long in the axial direction. Therefore, it is not necessary to lengthen the female threaded portion 42e of the worm wheel 42 to lengthen the stroke of the rod 26, and the female threaded portion 42e is formed relatively short in the axial direction. When molding the worm wheel 42, the female threaded mold in the mold must be rotated to remove it, but the short female threaded portion 42e shortens the time required for removal, thereby shortening the molding cycle of the worm wheel 42.

[0057] It is possible to increase the stroke of the rod 26 by lengthening the internal thread portion 42e of the worm wheel 42, and thus the worm wheel 42 itself, in the axial direction. However, because the arms 26d_l and 26d_r must always be positioned outside the worm wheel 42, i.e., behind the worm wheel 42, increasing the axial length of the worm wheel 42 would require the rod 26 to also be lengthened in the axial direction. Lengthening the rod 26 in the axial direction has various disadvantages. For example, increasing the axial length of the rod 26 increases the material cost of the rod 26. Furthermore, the rod 26 needs to be hollow to prevent sink marks. However, increasing the axial length of the rod 26 naturally requires a longer core for hollowing the rod 26, resulting in a larger mold. Furthermore, a longer core increases the time required to remove the core, lengthening the molding cycle of the rod 26. Furthermore, in injection molding, resin is injected into a mold under high pressure, and the longer the core, the more likely it is to tilt due to the pressure, which may cause deformation of the core. Therefore, it is desirable to increase the stroke of the rod 26 by lengthening the male thread portion 26g of the rod 26 in the axial direction.

[0058] Furthermore, in this embodiment, the long stroke of the rod 26 is achieved by forming the male threaded portion 26g of the rod 26 long in the axial direction, so that the front side of the male threaded portion 26g can protrude from the opening 34c to the outside of the case 24. In contrast, according to this embodiment, both front and rear end edges 34e, 34f of the restricting portion 34d are chamfered. The chamfered shape of both front and rear end edges 34e, 34f prevents the male threaded portion 26g of the rod 26 from getting caught on the restricting portion 34d, allowing the rod 26 to move smoothly back and forth.

[0059] Furthermore, according to this embodiment, both front and rear end edges 26s1, 26s2 of the threaded portion 26s of the male threaded portion 26g are chamfered. By chamfering both end edges 26s1, 26s2, the male threaded portion 26g of the rod 26 is prevented from getting caught on the restricting portion 34d, and the rod 26 can be moved back and forth smoothly.

[0060] Furthermore, according to the present embodiment, the arms 26d_l, 26d_r of the rod 26 engage with the engaging portions 36a_l, 36a_r of the second case portion 36 over the entire range of the stroke of the rod 26, and do not engage with or come into contact with the first case portion 34. In other words, over the entire range of the stroke of the arms 26d_l, 26d_r, there is no switching of the engaging partners with which the arms 26d_l, 26d_r engage. Therefore, the rod 26 can be moved smoothly back and forth over the entire range of the stroke of the rod 26.

[0061] (Second embodiment) See Figures 11 to 17. Figure 11 shows a cross section of the case 24 and the worm wheel 42. Figure 12 shows a cross section of the case 24. Figure 14 is a cross section of the actuator 17 taken along line B-B in Figure 11. Figure 17 is a cross section of the rod 26 taken along line CC in Figure 15. The substrate 30 is not shown in Figures 11 and 12.

[0062] As in the first embodiment, the actuator 17 includes a case 24, a rod 26, a motor 28, a substrate 30, and a movement mechanism 32. The following description will focus on the differences from the first embodiment.

[0063] As in the first embodiment, the rod 26 is made of resin and is injection molded. The rod 26 has a notch 26m extending in the axial direction in a portion of its circumference. In the illustrated example, the rod 26 has two notches 26m. The notches 26m can also be considered as hollowed-out portions. The number of notches 26m is not particularly limited as long as it does not impair the function of the male thread portion 26g.

[0064] The rod 26 has a recessed portion 26p recessed radially inward from the root of the male thread portion 26g. Although not particularly limited, in the illustrated example, the rod 26 has the recessed portion 26p formed in all the roots of the male thread portion 26g. The spherical portion 26e has at least one recessed portion 26q, and in the illustrated example, multiple recessed portions 26q.

[0065] In any case, by forming a hollowed-out portion in the rod 26 to the extent that the function of each portion of the rod 26 is not impaired, the thick portion of the rod 26 can be reduced or eliminated.

[0066] The cutout portion 26m has a trace 26r of the parting line of the mold used for injection molding. The trace 26r of the parting line is, for example, a line corresponding to the parting line or a trace left after removing the line. In this case, it is possible to reduce the amount of the male thread portion 26g near the parting line that could become an undercut portion.

[0067] As shown in the figure, the notch 26m preferably extends in the axial direction over at least the range in which the male thread portion 26g is provided. Also, as shown in the figure, the rod 26 preferably has at least two notches 26m that are radially opposed to each other. In this case, the male thread portion 26g near the parting line of the rod 26, which could potentially become an undercut portion, can be further reduced or eliminated.

[0068] The restricting portion 34d has a first restricting surface 34k_1, a second restricting surface 34k_2, a third restricting surface 34k_3, and a fourth restricting surface 34k_4. The first restricting surface 34k_1 and the second restricting surface 34k_2 are all planes perpendicular to the first direction and face each other in the first direction with the rod 26 between them. The first direction is a direction perpendicular to the axial direction of the rod 26. The third restricting surface 34k_3 and the fourth restricting surface 34k_4 are all planes perpendicular to the second direction and face each other in the second direction with the protrusion 26t of the rod 26 between them. The second direction is a direction perpendicular to both the axial direction of the rod 26 and the first direction.

[0069] One of the two cutout portions 26m, a cutout portion 26m_1, has a first cutout surface 26u_1, a third cutout surface 26u_3, and a fourth cutout surface 26u_4. The other of the two cutout portions 26m, a cutout portion 26m_2, has a second cutout surface 26u_2, a third cutout surface 26u_3, and a fourth cutout surface 26u_4.

[0070] The first cutout surface 26u_1 and the second cutout surface 26u_2 are both flat surfaces perpendicular to the first direction. The first cutout surface 26u_1 faces the first restriction surface 34k_1 in the first direction. The second cutout surface 26u_2 faces the second restriction surface 34k_2 in the first direction. When the rod 26 is displaced in the first direction, the first cutout surface 26u_1 comes into surface contact with the first restriction surface 34k_1, or the second cutout surface 26u_2 comes into surface contact with the second restriction surface 34k_2. In other words, the displacement of the rod 26 in the first direction is restricted by the first cutout surface 26u_1 coming into surface contact with the first restriction surface 34k_1 or the second cutout surface 26u_2 coming into surface contact with the second restriction surface 34k_2. This suppresses significant rattle of the rod 26 in the first direction.

[0071] The third cutout surface 26u_3 and the fourth cutout surface 26u_4 are planes perpendicular to the second direction. The third cutout surface 26u_3 faces the third restriction surface 34k_3 in the second direction. The fourth cutout surface 26u_4 faces the fourth restriction surface 34k_4 in the second direction. When the rod 26 is displaced in the second direction, the third cutout surface 26u_3 comes into surface contact with the third restriction surface 34k_3, or the fourth cutout surface 26u_4 comes into surface contact with the fourth restriction surface 34k_4. In other words, the displacement of the rod 26 in the second direction is suppressed by the third cutout surface 26u_3 coming into surface contact with the third restriction surface 34k_3 or the fourth cutout surface 26u_4 coming into surface contact with the fourth restriction surface 34k_4. This suppresses significant rattle of the rod 26 in the second direction.

[0072] Although not particularly limited, in the illustrated example, the first direction is the up-down direction, and the second direction is the left-right direction. That is, in the illustrated example, the first restriction surface 34k_1 and the second restriction surface 34k_2 are both surfaces perpendicular to the up-down direction and face each other in the up-down direction with the rod 26 therebetween. The third restriction surface 34k_3 and the fourth restriction surface 34k_4 are both surfaces perpendicular to the left-right direction and face each other in the left-right direction with the protrusion 26t of the rod 26 therebetween. Furthermore, the first restriction surface 34k_1, the second restriction surface 34k_2, the third restriction surface 34k_3, and the fourth restriction surface 34k_4 are surfaces facing downward, upward, right, and left, respectively.

[0073] In the illustrated example, the restricting portion has a first recess 34m_1 recessed upward from the first restricting surface 34k_1 and a second recess 34m_2 recessed downward from the second restricting surface 34k_2. The left and right inner wall surfaces of the first and second recesses 34m_1 and 34m_2 respectively constitute third and fourth restricting surfaces 34k_3 and 34k_4. In the illustrated example, the cutout 26m_1 has a first protrusion 26t_1 protruding upward from the first cutout surface 26u_1, and the cutout 26m_2 has a second protrusion 26t_2 protruding downward from the second cutout surface 26u_2. The left and right side surfaces of the first and second protrusions 26t_1 and 26t_2 respectively constitute third and fourth cutout surfaces 26u_3 and 26u_4.

[0074] In the illustrated example, the protrusion 26t_1 is accommodated in the first recess 34m_1, and the third and fourth cutout surfaces 26u_3 and 26u_4 of the first protrusion 26t_1 face the third and fourth restriction surfaces 34k_3 and 34k_4 of the first recess 34m_1 in the second direction. The second protrusion 26t_2 is accommodated in the second recess 34m_2, and the third and fourth cutout surfaces 26u_3 and 26u_4 of the second protrusion 26t_2 face the third and fourth restriction surfaces 34k_3 and 34k_4 of the second recess 34m_2 in the second direction.

[0075] According to the present embodiment described above, it is possible to achieve the same effects as those of the first embodiment.

[0076] Furthermore, according to this embodiment, a hollow portion is formed in the rod 26, which reduces or eliminates the thick portion of the rod 26. This eliminates the need to form the rod 26 hollow to prevent sink marks, which facilitates molding of the rod 26. Furthermore, because a core is not required to form the rod 26 hollow, the mold for molding the rod 26 can be made smaller or simpler.

[0077] Furthermore, according to this embodiment, the rod 26 has a notch 26m extending in the axial direction in a part of the circumferential direction, which makes it possible to reduce the male thread portion 26g near the parting line, which may become an undercut portion.

[0078] Furthermore, according to this embodiment, the notch 26m preferably extends in the axial direction over at least the range in which the male thread portion 26g is provided. Furthermore, the rod 26 preferably has at least two notches 26m that are radially opposed to each other. In this case, the male thread portion 26g near the parting line of the rod 26, which could potentially become an undercut portion, can be further reduced or eliminated.

[0079] When restricting the displacement of the rod 26 by contacting the male threaded portion 26g of the rod 26 with the restricting portion 34d, it is necessary to control whether the inner circumferential surface of the restricting portion 34d that contacts the rod 26 is a perfect circle, making it difficult to control the dimensions of the rod 26 and the restricting portion 34d. In contrast, according to this embodiment, the notched portion 26m of the rod 26 contacts the restricting portion 34d, thereby restricting the vertical and horizontal displacement of the rod 26, i.e., the radial displacement of the rod 26. In particular, the radial displacement of the rod 26 is restricted by the surface contact between the notched surface and the restricting surface, which are planar to each other. In this case, it is only necessary to control whether the notched surface and the corresponding restricting surface are parallel, which is relatively easy to control. Furthermore, their manufacture is also relatively easy. Furthermore, because the male threaded portion 26g of the rod 26 does not get caught on the restricting portion 34d, the rod 26 can be moved smoothly back and forth.

[0080] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention. These modifications will be described below.

[0081] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. A new embodiment resulting from a combination will have the combined effects of the combined embodiments and modifications. It will also be understood by those skilled in the art that the functions to be performed by each constituent element recited in the claims can be realized by each constituent element shown in the embodiments and modifications, either alone or in combination.

[0082] The above-described embodiment can be generalized to provide the following aspects.

[0083] [Aspect 1] An actuator comprising: a case having an opening; a rod housed in the case, the tip of which protrudes outside the case through the opening; a motor housed in the case; and a movement mechanism housed in the case and driven by the motor to move the rod in its axial direction, wherein the movement mechanism includes an annular member through which the rod is inserted, and movement of the annular member in the axial direction is restricted, the rod has a male threaded portion on its outer periphery and the annular member has a female threaded portion on its inner periphery that screws into the male threaded portion, and the rod moves in the axial direction in response to rotation of the annular member, the case has a restricting portion on the axial side where the tip is located relative to the annular member, and the rod has a notch extending in the axial direction in part of its circumferential direction, and radial displacement is restricted by contact of the notch with the restricting portion.

[0084] [Aspect 2] The actuator according to aspect 1, wherein the radial displacement of the rod is restricted by the cutout portion coming into surface contact with the restricting portion.

[0085] [Aspect 3] The actuator according to Aspect 1 or 2, wherein the cutout portion has a protrusion extending in the axial direction, the restricting portion has a recess corresponding to the protrusion, and the radial displacement of the rod is restricted by the protrusion contacting the recess.

[0086] [Aspect 4] The actuator according to any one of Aspects 1 to 3, wherein the rod has a spherical portion at a tip end that is rotatably gripped, and the spherical portion has a hollowed-out portion.

[0087] [Aspect 5] An actuator comprising: a case having an opening; a rod housed in the case, the tip of which protrudes outside the case through the opening; a motor housed in the case; and a movement mechanism housed in the case and driven by the motor to move the rod in its axial direction, wherein the movement mechanism includes an annular member through which the rod is inserted, the annular member being restricted from moving in the axial direction, the rod having a male threaded portion on its outer periphery and the annular member having a female threaded portion on its inner periphery that screws into the male threaded portion, the rod moving in the axial direction in response to rotation of the annular member, and a portion of the male threaded portion being exposed from the annular member.

[0088] [Aspect 6] The actuator according to aspect 5, wherein the male thread portion is longer in the axial direction than the female thread portion.

[0089] [Aspect 7] The actuator according to Aspect 5 or 6, wherein the case has a restricting portion located closer to the tip than the annular member, the radial displacement of the rod is restricted by contact with the restricting portion, and both axial end edges of the restricting portion have a chamfered shape.

[0090] [Aspect 8] An actuator described in any of Aspects 5 to 7, wherein the case is box-shaped and includes a first case portion and a second case portion connected to each other opposite to each other in the axial direction, the first case portion has the opening, the rod has an arm extending in the axial direction away from the tip, and the arm engages with an engaging portion of the second case portion over the entire range of the stroke of the rod, thereby restricting rotation of the rod.

[0091] [Aspect 9] An actuator comprising: a case having an opening; a rod housed in the case, the tip of which protrudes outside the case through the opening; a motor housed in the case; and a movement mechanism housed in the case and driven by the motor to move the rod in its axial direction, wherein the movement mechanism includes an annular member through which the rod is inserted, the movement of the annular member in the axial direction being restricted, the rod having a male threaded portion on its outer periphery and a female threaded portion on its inner periphery that screws into the male threaded portion, the rod moving in the axial direction in response to rotation of the annular member, and the rod being made of resin and having a notch extending in the axial direction in part of its circumferential direction.

[0092] [Aspect 10] The actuator according to Aspect 9, wherein the notch portion extends in the axial direction over at least a range in which the male thread portion is provided.

[0093] [Aspect 11] The actuator according to Aspect 9 or 10, wherein the rod has the notched portions at least in two locations that face each other in the radial direction.

[0094] [Aspect 12] The actuator according to any one of Aspects 9 to 11, wherein the cutout portion has a trace of a parting line of a mold used for injection molding.

[0095] [Aspect 13] The actuator according to any one of Aspects 9 to 12, wherein the rod has a spherical portion at a tip end thereof that is rotatably gripped, and the spherical portion has a hollowed-out portion.

[0096] The present invention can be used in an actuator.

[0097] 1 Vehicle lighting fixture, 17 Actuator, 24 Case, 26 Rod, 26d Arm, 26e Spherical portion, 26g Male thread portion, 26m Notch portion, 26t Protrusion portion, 28 Motor, 32 Moving mechanism, 34 First case portion, 34c Opening, 34d Restricting portion, 34m_1 First recess, 34m_2 Second recess, 36 Second case portion, 36a_l, 36a_r Engagement portion, 42 Worm wheel, 42e Female thread portion.

Claims

1. An actuator comprising: a case having an opening; a rod housed within the case, the tip of which protrudes outside the case through the opening; a motor housed within the case; and a moving mechanism housed within the case and driven by the motor to move the rod in its axial direction, wherein the moving mechanism includes an annular member through which the rod is inserted, the movement of the annular member being restricted in the axial direction, the rod having a male threaded portion on its outer periphery and the annular member having a female threaded portion on its inner periphery which screws into the male threaded portion, and the rod moves in the axial direction in response to rotation of the annular member, the case having a restricting portion on the axial side where the tip is located relative to the annular member, and the rod has a notch extending in the axial direction in part of its circumferential direction, and radial displacement is restricted by the notch coming into contact with the restricting portion.

2. The actuator according to claim 1, wherein the radial displacement of the rod is restricted by surface contact of the notch with the restricting portion.

3. An actuator as described in claim 1, wherein the cutout portion has a protrusion extending in the axial direction, the regulating portion has a recess corresponding to the protrusion, and the radial displacement of the rod is regulated by the protrusion coming into contact with the recess.

4. The actuator according to claim 1, wherein the rod has a ball portion at a tip thereof that is rotatably held, and the ball portion has a hollowed-out portion.

5. An actuator comprising: a case having an opening; a rod housed within the case, the tip of which protrudes outside the case through the opening; a motor housed within the case; and a moving mechanism housed within the case and driven by the motor to move the rod in its axial direction, wherein the moving mechanism includes an annular member through which the rod is inserted, the annular member being restricted in its axial movement, the rod having a male threaded portion on its outer periphery and a female threaded portion on its inner periphery which screws into the male threaded portion, the rod moving in the axial direction in response to rotation of the annular member, and a portion of the male threaded portion being exposed from the annular member.

6. The actuator according to claim 5, wherein the male thread portion is longer in the axial direction than the female thread portion.

7. An actuator as described in claim 5, wherein the case has a regulating portion on the tip side of the annular member, the radial displacement of the rod is regulated by contact with the regulating portion, and both axial end edges of the regulating portion have a chamfered shape.

8. An actuator as described in claim 5, wherein the case is box-shaped and includes a first case portion and a second case portion connected to each other facing each other in the axial direction, the first case portion having the opening, the rod having an arm extending in the axial direction away from the tip, and the arm engaging with an engaging portion of the second case portion over the entire range of the stroke of the rod, thereby regulating rotation of the rod.

9. An actuator comprising: a case having an opening; a rod housed within the case, the tip of which protrudes outside the case through the opening; a motor housed within the case; and a moving mechanism housed within the case and driven by the motor to move the rod in its axial direction, wherein the moving mechanism includes an annular member through which the rod is inserted, the annular member being restricted in its axial movement, the rod having a male threaded portion on its outer periphery and a female threaded portion on its inner periphery which screws into the male threaded portion, the rod moving in the axial direction in response to rotation of the annular member, and the rod being made of resin and having a notch extending in the axial direction along part of its circumferential direction.

10. The actuator according to claim 9, wherein the notch portion extends in the axial direction over at least the range in which the male thread portion is provided.

11. The actuator according to claim 9, wherein the rod has the notches at least in two locations opposed to each other in the radial direction.

12. The actuator according to claim 9, wherein the cutout portion has a trace of a parting line of a mold used for injection molding.

13. The actuator according to claim 9, wherein the rod has a ball portion at a tip end thereof that is rotatably held, and the ball portion has a hollowed-out portion.

Images