JP2021152397A

JP2021152397A - Linear actuator

Info

Publication number: JP2021152397A
Application number: JP2020053568A
Authority: JP
Inventors: 一彦熊井戸; Kazuhiko Kumaido; 純一阿部; Junichi Abe
Original assignee: Nidec Copal Electronics Corp
Current assignee: Nidec Copal Electronics Corp
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2021-09-30

Abstract

To provide a linear actuator which enables a shaft to move quickly from its stopped state.SOLUTION: A motor 12 is provided within a housing. A cylindrical body 14 having a female screw 14a is rotated by the motor. A shaft 17 has a male screw 17a which is threadedly engaged with the female screw of the cylindrical body at a part thereof. A projection 19 is provided at the shaft. A guide part 20 is provided along the shaft in the housing, guides the projection, and has bending parts 20a, 20b, bend obliquely relative to a shaft moving direction, in at least one end part as seen in the shaft moving direction.SELECTED DRAWING: Figure 1

Description

本発明の実施形態は、例えばリニアアクチュエータに関する。 Embodiments of the present invention relate, for example, to linear actuators.

モータの回転運動を例えば送りねじ機構によって直線運動に変換し、シャフトを直線状に移動させるリニアアクチュエータが知られている（例えば特許文献１参照）。 A linear actuator is known in which the rotational motion of a motor is converted into a linear motion by, for example, a feed screw mechanism, and the shaft is linearly moved (see, for example, Patent Document 1).

特許第６５４９８２６号公報Japanese Patent No. 6548926

送りねじ機構を用いたリニアアクチュエータは、例えばモータにより回転される雌ねじが設けられたナットと、一部に雄ねじが設けられたシャフトと、シャフトに設けられた突起と、突起が当接するストッパと、を具備している。シャフトの雄ねじはナットの雌ねじに螺合され、ナットが回転されることにより、シャフトが直線運動する。シャフトに設けられた突起がストッパに当接することにより、シャフトの動きが停止され、モータも停止される。モータが逆に回転されると、ナットも逆に回転され、シャフトが元の位置の方向に駆動される。 A linear actuator using a feed screw mechanism includes, for example, a nut provided with a female screw rotated by a motor, a shaft provided with a male screw partly, a protrusion provided on the shaft, and a stopper with which the protrusion abuts. Is equipped with. The male screw of the shaft is screwed into the female screw of the nut, and the nut is rotated to cause the shaft to move linearly. When the protrusion provided on the shaft comes into contact with the stopper, the movement of the shaft is stopped and the motor is also stopped. When the motor is rotated in the opposite direction, the nut is also rotated in the opposite direction, driving the shaft in the direction of its original position.

モータは、突起がストッパに当接するタイミングで停止される。しかし、突起がストッパに当接したタイミングにおいて、ナットによりシャフトに駆動力が印加されているため、ナットの雌ねじとシャフトの雄ねじが強く締め付けられる。したがって、雌ねじと雄ねじとの摩擦力が大きくなるため、モータが逆回転された場合においても、シャフトは停止位置から迅速に動くことが困難であった。 The motor is stopped at the timing when the protrusion abuts on the stopper. However, since the driving force is applied to the shaft by the nut at the timing when the protrusion comes into contact with the stopper, the female screw of the nut and the male screw of the shaft are strongly tightened. Therefore, since the frictional force between the female screw and the male screw becomes large, it is difficult for the shaft to move quickly from the stop position even when the motor is rotated in the reverse direction.

本発明の実施形態は、シャフトを停止された状態から迅速に動かすことが可能なリニアアクチュエータを提供する。 An embodiment of the present invention provides a linear actuator capable of rapidly moving a shaft from a stopped state.

本実施形態のリニアアクチュエータは、ハウジングと、前記ハウジング内に設けられたモータと、前記モータにより回転され、雌ねじを有する筒体と、一部に前記筒体の雌ねじに螺合される雄ねじを有するシャフトと、前記シャフトに設けられた突起と、前記ハウジング内で前記シャフトに沿って設けられ、前記突起を案内し、前記シャフトの移動方向の少なくとも一端部に、前記シャフトの移動方向に対して斜めに屈曲された屈曲部を有する案内部と、を具備する。 The linear actuator of the present embodiment has a housing, a motor provided in the housing, a cylinder rotated by the motor and having a female screw, and a male screw partially screwed into the female screw of the cylinder. A shaft, a protrusion provided on the shaft, and a protrusion provided along the shaft in the housing to guide the protrusion and at least one end in the movement direction of the shaft at an angle to the movement direction of the shaft. It is provided with a guide portion having a bent portion that is bent.

本実施形態に係るリニアアクチュエータを示すものであり、一部を除いた上面図。The linear actuator according to this embodiment is shown, and the top view is a top view except for a part. 図１のＩＩ−ＩＩ線に沿った断面図。FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 図２Ａの一部を取り出して示す上面図。Top view showing a part of FIG. 2A taken out. 図２Ａの一部の変形例を示す上面図。Top view showing a partial modification of FIG. 2A. 図２Ａと異なる動作状態を示す断面図。FIG. 2 is a cross-sectional view showing an operating state different from that of FIG. 2A. 図３Ａの一部を取り出して示す上面図。Top view showing a part of FIG. 3A taken out. 図３Ａと異なる動作状態を示す断面図。FIG. 3 is a cross-sectional view showing an operating state different from that of FIG. 3A. 図４Ａの一部を取り出して示す上面図。Top view showing a part of FIG. 4A taken out. 図３Ａと異なる動作状態を示す断面図。FIG. 3 is a cross-sectional view showing an operating state different from that of FIG. 3A. 図４Ａの一部を取り出して示す上面図。Top view showing a part of FIG. 4A taken out. 第１変形例を示すものであり、要部を取り出して示す上面図。The first modification is shown, and the top view which shows the main part by taking out. 第２変形例を示すものであり、要部を取り出して示す上面図。The second modification is shown, and the top view which shows the main part by taking out.

以下、実施の形態について、図面を参照して説明する。図面において、同一部分には、同一符号を付している。 Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same parts are designated by the same reference numerals.

図１、図２Ａ、図２Ｂは、本実施形態に係るリニアアクチュエータ１０を示している。リニアアクチュエータ１０のハウジング１１は、本体１１ａと、図２Ａに示すカバー１１ｂを有し、カバー１１ｂは、本体１１ａに取り付けられる。本体１１ａの内部には、隔壁１１ｃが設けられ、本体１１ａの内部は、隔壁１１ｃにより仕切られる。隔壁１１ｃは、本体１１ａ及びカバー１１ｂの両方に分割して設けられている。 1, FIG. 2A, and FIG. 2B show a linear actuator 10 according to this embodiment. The housing 11 of the linear actuator 10 has a main body 11a and a cover 11b shown in FIG. 2A, and the cover 11b is attached to the main body 11a. A partition wall 11c is provided inside the main body 11a, and the inside of the main body 11a is partitioned by the partition wall 11c. The partition wall 11c is divided into both the main body 11a and the cover 11b.

本体１１ａの内部において、隔壁１１ｃで仕切られた一方側には、モータ１２が配置され、他方側には、減速機１３が配置されている。減速機１３は、例えば複数の歯車１３ａ、１３ｂ、１３ｃ、１３ｄを含んでいる。歯車１３ａは、モータ１２のシャフトに設けられ、歯車１３ｂは、歯車１３ａに歯合されている。歯車１３ｃは、歯車１３ｂと一体化され、歯車１３ｄに歯合されている。歯車１３ｄは、送りねじ機構を構成する筒体１４と一体化されている。減速機１３の構成は、これに限定されるものではなく、変形可能である。 Inside the main body 11a, the motor 12 is arranged on one side partitioned by the partition wall 11c, and the speed reducer 13 is arranged on the other side. The speed reducer 13 includes, for example, a plurality of gears 13a, 13b, 13c, 13d. The gear 13a is provided on the shaft of the motor 12, and the gear 13b is meshed with the gear 13a. The gear 13c is integrated with the gear 13b and meshed with the gear 13d. The gear 13d is integrated with the tubular body 14 that constitutes the feed screw mechanism. The configuration of the speed reducer 13 is not limited to this, and is deformable.

歯車１３ｄ及び筒体１４は、軸受１５及び軸受１６により回転可能に保持されている。軸受１５は、本体１１ａに設けられ、軸受１６は、隔壁１１ｃに設けられている。 The gear 13d and the cylinder 14 are rotatably held by the bearing 15 and the bearing 16. The bearing 15 is provided on the main body 11a, and the bearing 16 is provided on the partition wall 11c.

図２Ａに示すように、送りねじ機構は、筒体１４とシャフト１７により構成される。筒体１４の内面には、雌ねじ１４ａが設けられている。シャフト１７の第１端部は、本体１１ａの側面を貫通して配置され、シャフト１７は、本体１１ａに設けられた軸受１８により回転可能に保持されている。シャフト１７の第２端部は、筒体１４の内部に配置される。シャフト１７の第２端部には、雄ねじ１７ａが設けられ、雄ねじ１７ａは、筒体１４の雌ねじ４ａに螺合されている。このため、筒体１４が回転されると、雌ねじ１４ａと雄ねじ１７ａとにより回転運動が直線運動に変換され、シャフト１７は、シャフト１７の軸心方向に移動される。 As shown in FIG. 2A, the feed screw mechanism is composed of a tubular body 14 and a shaft 17. A female screw 14a is provided on the inner surface of the tubular body 14. The first end portion of the shaft 17 is arranged so as to penetrate the side surface of the main body 11a, and the shaft 17 is rotatably held by a bearing 18 provided on the main body 11a. The second end of the shaft 17 is arranged inside the tubular body 14. A male screw 17a is provided at the second end of the shaft 17, and the male screw 17a is screwed into the female screw 4a of the tubular body 14. Therefore, when the tubular body 14 is rotated, the rotary motion is converted into a linear motion by the female screw 14a and the male screw 17a, and the shaft 17 is moved in the axial direction of the shaft 17.

シャフト１７の中間部には、突起１９が設けられている。突起１９は、例えば円柱状であり、シャフト１７の軸心に対して直交方向に設けられている。シャフト１７及び突起１９は、例えば金属製であるが、金属に限定されるものではなく、樹脂であってもよく、突起１９は、弾性を有する材料により構成されてもよい。 A protrusion 19 is provided in the middle portion of the shaft 17. The protrusion 19 is, for example, a columnar shape, and is provided in a direction orthogonal to the axis of the shaft 17. The shaft 17 and the protrusion 19 are made of metal, for example, but are not limited to metal, and may be made of resin, and the protrusion 19 may be made of an elastic material.

本体１１ａの底部には、シャフト１７の軸心に沿って溝２０が設けられている。溝２０は、突起１９の案内部として機能し、図２Ａ、図２Ｂに示すように、直線部２０ｃ、第１屈曲部２０ａ、及び第２屈曲部２０ｂを有している。直線部２０ｃ、第１屈曲部２０ａ、及び第２屈曲部２０ｂの幅Ｗは、突起１９の直径Ｄ１より若干大きく、突起１９が溝２０に沿って移動可能とされている。溝２０の長さＬ１は、シャフト１７及び突起１９の移動範囲に対応している。 A groove 20 is provided at the bottom of the main body 11a along the axis of the shaft 17. The groove 20 functions as a guide portion of the protrusion 19, and has a straight portion 20c, a first bent portion 20a, and a second bent portion 20b as shown in FIGS. 2A and 2B. The width W of the straight portion 20c, the first bent portion 20a, and the second bent portion 20b is slightly larger than the diameter D1 of the protrusion 19, and the protrusion 19 is movable along the groove 20. The length L1 of the groove 20 corresponds to the moving range of the shaft 17 and the protrusion 19.

第１屈曲部２０ａは、溝２０の第１端部（直線部２０ｃの第１端部）に設けられ、第２屈曲部２０ｂは、溝２０の第２端部（直線部２０ｃの第２端部）に設けられている。第１屈曲部２０ａは、シャフト１７の第１回転方向（図示矢印Ａ方向で、第１方向とも言う）に対して斜めに屈曲されている。換言すると、第１屈曲部２０ａの平行する２つの側面は、直線部２０ｃの平行する２つの側面に対して斜めに配置され、２つの側面の間の側面（第１屈曲部２０ａの端面）は、直線部２０ｃに対して斜めに配置されている。第２屈曲部２０ｂは、シャフト１７の第２回転方向（図示矢印Ｂ方向で、第２方向とも言う）に対して斜めに屈曲されている。換言すると、第２屈曲部２０ｂの平行する２つの側面は、直線部２０ｃの平行する２つの側面に対して第１屈曲部２０ａと反対方向に斜めに配置され、２つの側面の間の側面（第２屈曲部２０ｂの端面）は、直線部２０ｃに対して斜めに配置されている。第１屈曲部２０ａの端面と第２屈曲部２０ｂの端面は、平行に配置されている。 The first bent portion 20a is provided at the first end portion of the groove 20 (the first end portion of the straight portion 20c), and the second bent portion 20b is the second end portion of the groove 20 (the second end of the straight portion 20c). It is provided in the section). The first bent portion 20a is bent obliquely with respect to the first rotation direction of the shaft 17 (in the direction of arrow A in the drawing, also referred to as the first direction). In other words, the two parallel side surfaces of the first bent portion 20a are arranged obliquely with respect to the two parallel side surfaces of the straight portion 20c, and the side surface between the two side surfaces (the end surface of the first bent portion 20a) is , Arranged diagonally with respect to the straight portion 20c. The second bent portion 20b is bent obliquely with respect to the second rotation direction of the shaft 17 (in the direction of arrow B in the drawing, also referred to as the second direction). In other words, the two parallel side surfaces of the second bent portion 20b are arranged obliquely in the direction opposite to the first bent portion 20a with respect to the two parallel side surfaces of the straight portion 20c, and the side surface between the two side surfaces ( The end face of the second bent portion 20b) is arranged obliquely with respect to the straight portion 20c. The end face of the first bent portion 20a and the end face of the second bent portion 20b are arranged in parallel.

第１屈曲部２０ａ及び第２屈曲部２０ｂは、図２Ａに破線で示すように、本体１１ａの底部に形成された例えば円弧状の溝である。しかし、円弧状の溝に限定されるものではなく、突起１９が回転して移動することが可能な空間であればよい。 The first bent portion 20a and the second bent portion 20b are, for example, arcuate grooves formed in the bottom portion of the main body 11a, as shown by a broken line in FIG. 2A. However, the space is not limited to the arcuate groove, and any space may be used as long as the protrusion 19 can rotate and move.

シャフト１７は、筒体１４が回転されると、雌ねじ１４ａと雄ねじ１７ａの摩擦力により、筒体１４の回転方向と同一方向に回転力を受けている。しかし、突起１９が溝２０の直線部２０ｃに位置するとき、突起１９は溝２０の側壁に接することにより、シャフト１７の回転が抑えられる。このため、突起１９は、回転されず、溝２０の直線部２０ｃに沿って移動する。突起１９が溝２０の第１屈曲部２０ａに位置するとき、突起１９は、シャフト１７の回転力により、第１屈曲部２０ａに沿って僅かに回転しながら移動する。また、突起１９が溝２０の第２端部に位置するとき、突起１９は、シャフト１７の回転力により、第２屈曲部２０ｂに沿って僅かに回転しながら移動する。 When the tubular body 14 is rotated, the shaft 17 receives a rotational force in the same direction as the rotational direction of the tubular body 14 due to the frictional force between the female screw 14a and the male screw 17a. However, when the protrusion 19 is located in the straight portion 20c of the groove 20, the protrusion 19 comes into contact with the side wall of the groove 20, so that the rotation of the shaft 17 is suppressed. Therefore, the protrusion 19 does not rotate and moves along the straight portion 20c of the groove 20. When the protrusion 19 is located at the first bent portion 20a of the groove 20, the protrusion 19 moves while slightly rotating along the first bent portion 20a due to the rotational force of the shaft 17. Further, when the protrusion 19 is located at the second end of the groove 20, the protrusion 19 moves while slightly rotating along the second bent portion 20b due to the rotational force of the shaft 17.

尚、突起１９を案内する案内部は、溝２０に限定されるものではなく、図２Ｃに示すように、直線部２０ｃ、第１屈曲部２０ａ、及び第２屈曲部２０ｂを有する突部２１であってもよい。すなわち、直線部２０ｃは、平行する２つの側面を有し、第１屈曲部２０ａ及び第２屈曲部２０ｂも平行する２つの側面と、平行する２つの側面の間に配置された側面をそれぞれ有している。 The guide portion for guiding the protrusion 19 is not limited to the groove 20, and as shown in FIG. 2C, the guide portion is a protrusion 21 having a straight portion 20c, a first bending portion 20a, and a second bending portion 20b. There may be. That is, the straight portion 20c has two parallel side surfaces, and the first bent portion 20a and the second bent portion 20b also have two parallel side surfaces and a side surface arranged between the two parallel side surfaces. doing.

（リニアアクチュエータの動作）
シャフト１７及び突起１９が図１、図２Ａ、図２Ｂに示す位置にある状態において、モータ１２が駆動され、筒体１４が第１方向（図示矢印Ａ方向）に回転されると、シャフト１７は、本体１１ａから突出する方向に移動される。 (Operation of linear actuator)
When the motor 12 is driven and the tubular body 14 is rotated in the first direction (direction of arrow A in the drawing) while the shaft 17 and the protrusion 19 are in the positions shown in FIGS. 1, 2A, and 2B, the shaft 17 is rotated. , It is moved in the direction of protruding from the main body 11a.

図３Ａ、図３Ｂに示すように、突起１９が溝２０の第１屈曲部２０ａ内に到達すると、突起１９は、第１屈曲部２０ａの側面に沿って第１屈曲部２０ａ内に侵入する。モータ１２は、突起１９が例えば第１屈曲部２０ａに到達したタイミングで停止される。突起１９が第１屈曲部２０ａ内に侵入することにより、シャフト１７が図示矢印Ａ方向に若干回転しながら移動して停止する。このため、雌ねじ１４ａと雄ねじ１７ａとの摩擦力は、第１屈曲部２０ａが無く、シャフト１７が回転せずに停止される場合に比べて低減される。 As shown in FIGS. 3A and 3B, when the protrusion 19 reaches the inside of the first bent portion 20a of the groove 20, the protrusion 19 penetrates into the first bent portion 20a along the side surface of the first bent portion 20a. The motor 12 is stopped when the protrusion 19 reaches, for example, the first bent portion 20a. When the protrusion 19 penetrates into the first bent portion 20a, the shaft 17 moves and stops while slightly rotating in the direction of arrow A in the drawing. Therefore, the frictional force between the female screw 14a and the male screw 17a is reduced as compared with the case where the shaft 17 is stopped without rotating because there is no first bent portion 20a.

突起１９が第１屈曲部２０ａ内に位置した状態において、モータ１２が逆方向に駆動され、筒体１４が図２Ａに示す矢印Ｂ方向に回転されると、シャフト１７は、本体１１ａに侵入する方向に移動される。 When the motor 12 is driven in the opposite direction and the tubular body 14 is rotated in the direction of arrow B shown in FIG. 2A in a state where the protrusion 19 is located in the first bent portion 20a, the shaft 17 invades the main body 11a. Moved in the direction.

図４Ａ、図４Ｂに示すように、シャフト１７の移動に従って、突起１９は、第１屈曲部２０ａの側面に沿って溝２０の直線部２０ｃ内に導かれる。突起１９は、直線部２０ｃ内を移動し、第２屈曲部２０ｂに到達すると、第２屈曲部２０ｂの側面に沿って第２屈曲部２０ｂ内に侵入する。モータ１２は、例えば突起１９が第２屈曲部２０ｂに到達したタイミングで停止される。突起１９が第２屈曲部２０ｂ内に侵入することにより、シャフト１７が図２Ａに示す矢印Ｂ方向に若干回転して停止する。このため、雌ねじ１４ａと雄ねじ１７ａとの摩擦力は、シャフト１７が回転せずに停止される場合に比べて低減される。 As shown in FIGS. 4A and 4B, as the shaft 17 moves, the protrusion 19 is guided into the straight portion 20c of the groove 20 along the side surface of the first bent portion 20a. The protrusion 19 moves in the straight portion 20c, and when it reaches the second bent portion 20b, it penetrates into the second bent portion 20b along the side surface of the second bent portion 20b. The motor 12 is stopped, for example, when the protrusion 19 reaches the second bent portion 20b. When the protrusion 19 penetrates into the second bent portion 20b, the shaft 17 rotates slightly in the direction of arrow B shown in FIG. 2A and stops. Therefore, the frictional force between the female screw 14a and the male screw 17a is reduced as compared with the case where the shaft 17 is stopped without rotating.

突起１９が第２屈曲部２０ｂ内に位置した状態において、モータ１２が逆方向に駆動され、筒体１４が図２Ａに示す矢印Ａ方向に回転されると、シャフト１７の移動に従って、突起１９は、第２屈曲部２０ｂの側面に沿って溝２０の直線部２０ｃ内に導かれる。 When the motor 12 is driven in the opposite direction and the tubular body 14 is rotated in the direction of arrow A shown in FIG. 2A in a state where the protrusion 19 is located in the second bent portion 20b, the protrusion 19 is moved according to the movement of the shaft 17. , Is guided into the straight portion 20c of the groove 20 along the side surface of the second bent portion 20b.

モータ１２は、例えば図示せぬ磁性体と、２つの磁気センサと、制御部とを用いて制御される。磁性体は、シャフト１７の一部に設けられ、２つの磁気センサは、シャフト１７の移動方向に沿って離間して配置される。制御部によりモータ１２が例えばＡ方向に回転され、シャフト１７の移動に伴い２つの磁気センサの一方によって磁性体が検出されると、制御部によりモータ１２が停止される。また、制御部によりモータ１２が例えばＢ方向に回転され、シャフト１７の移動に伴い２つの磁気センサの他方により磁性体が検出されると、制御部によりモータ１２が停止される。 The motor 12 is controlled by using, for example, a magnetic material (not shown), two magnetic sensors, and a control unit. The magnetic material is provided on a part of the shaft 17, and the two magnetic sensors are arranged apart from each other along the moving direction of the shaft 17. When the motor 12 is rotated in the A direction by the control unit and a magnetic body is detected by one of the two magnetic sensors as the shaft 17 moves, the control unit stops the motor 12. Further, when the motor 12 is rotated in the B direction by the control unit and a magnetic body is detected by the other of the two magnetic sensors as the shaft 17 moves, the control unit stops the motor 12.

しかし、モータ１２の制御はこれに限定されるものではなく、モータ１２の負荷を検出してモータ１２を停止させる方法や、その他の方法を適用することも可能である。 However, the control of the motor 12 is not limited to this, and a method of detecting the load of the motor 12 and stopping the motor 12 or another method can be applied.

また、モータ１２を停止させるタイミングは、突起１９が第１屈曲部２２ａ又は第２屈曲部２２ｂに到達したときとした。しかし、これに限定されるものではなく、モータ１２は、雌ねじ１４ａと雄ねじ１７ａとの摩擦力の増大を抑制でき、シャフト１７が予め定められた位置に到達するタイミングで停止されればよい。 The timing for stopping the motor 12 is when the protrusion 19 reaches the first bent portion 22a or the second bent portion 22b. However, the present invention is not limited to this, and the motor 12 may be able to suppress an increase in the frictional force between the female screw 14a and the male screw 17a, and may be stopped at the timing when the shaft 17 reaches a predetermined position.

さらに、第１屈曲部２０ａ及び第２屈曲部２０ｂは、両方が必ずしも設けられる必要はなく、第１屈曲部２０ａ及び第２屈曲部２０ｂのどちらか一方のみを設けてもよい。 Further, both the first bent portion 20a and the second bent portion 20b do not necessarily have to be provided, and only one of the first bent portion 20a and the second bent portion 20b may be provided.

（第１屈曲部、第２屈曲部の作用）
第１屈曲部２０ａ及び第２屈曲部２０ｂの作用について、さらに具体的に説明する。 (Action of the first bent part and the second bent part)
The actions of the first bent portion 20a and the second bent portion 20b will be described more specifically.

図５Ａに示すように、溝２０に第１屈曲部２０ａ及び第２屈曲部２０ｂがない場合において、突起１９が溝２０の第１端部に停止した状態から第２端部方向へ移動するとき、シャフト１７の移動に伴い、突起１９は、矢印Ｃ方向に移動しようとする。この時、突起１９の移動方向と直交する溝２０の側面から側面に対して垂直方向の力Ｐｘと、側面に沿った方向の力Ｐｙが、突起１９に作用する。垂直方向の力Ｐｘは突起１９が移動するために必要な力であるが、側面に沿った方向の力Ｐｙは突起１９に対して摩擦力として作用し、突起１９をロックする力となる。 As shown in FIG. 5A, when the groove 20 does not have the first bent portion 20a and the second bent portion 20b, and the protrusion 19 moves from the state where the protrusion 19 is stopped at the first end portion of the groove 20 toward the second end portion. As the shaft 17 moves, the protrusion 19 tends to move in the direction of arrow C. At this time, a force Px in the direction perpendicular to the side surface from the side surface of the groove 20 orthogonal to the moving direction of the protrusion 19 and a force Py in the direction along the side surface act on the protrusion 19. The force Px in the vertical direction is a force required for the protrusion 19 to move, but the force Py in the direction along the side surface acts as a frictional force on the protrusion 19 and becomes a force for locking the protrusion 19.

しかし、図５Ｂに示す上記実施形態の場合、溝２０の第１端部には、第１屈曲部２０ａが設けられているため、側面と垂直方向の力Ｐｘが突起１９の移動方向（矢印Ｃ）と一致され、側面に沿った方向の力Ｐｙを低減さている。したがって、突起１９のロックが防止される。第２屈曲部２０ｂの作用も、第１屈曲部２０ａと同様である。 However, in the case of the above embodiment shown in FIG. 5B, since the first bent portion 20a is provided at the first end portion of the groove 20, the force Px in the direction perpendicular to the side surface is the moving direction of the protrusion 19 (arrow C). ), And the force Py in the direction along the side surface is reduced. Therefore, the protrusion 19 is prevented from being locked. The action of the second bent portion 20b is the same as that of the first bent portion 20a.

（実施形態の効果）
本実施形態によれば、溝２０は、直線部２０ｃと、直線部２０ｃの第１端部に設けられ、シャフト１７の第１移動方向に対して斜めの第１屈曲部２０ａと、直線部２０ｃの第２端部に設けられ、シャフト１７の第２移動方向に対して斜めの第２屈曲部２０ｂとを有している。このため、第１屈曲部２０ａ又は第２屈曲部２０ｂの内部で溝２０の側面に接触して停止した突起１９が、直線部２０ｃの方向に移動されるとき、溝２０の側面と突起１９との摩擦力を低減できる。したがって、突起１９は、第１屈曲部２０ａ又は第２屈曲部２０ｂの内部で停止した状態より、直線部２０ｃの方向に容易に移動することができる。 (Effect of embodiment)
According to the present embodiment, the grooves 20 are provided at the straight portion 20c and the first end portion of the straight portion 20c, and the first bent portion 20a and the straight portion 20c which are oblique to the first moving direction of the shaft 17 are provided. It has a second bent portion 20b that is provided at the second end portion of the shaft 17 and is oblique to the second moving direction of the shaft 17. Therefore, when the protrusion 19 that has stopped in contact with the side surface of the groove 20 inside the first bent portion 20a or the second bent portion 20b is moved in the direction of the straight portion 20c, the side surface of the groove 20 and the protrusion 19 Friction force can be reduced. Therefore, the protrusion 19 can easily move in the direction of the straight line portion 20c from the state of being stopped inside the first bent portion 20a or the second bent portion 20b.

しかも、上記実施形態によれば、溝２０は、第１屈曲部２０ａ及び第２屈曲部２０ｂを有し、シャフト１７に設けられた突起１９は、溝２０の第１端部に到達すると、第１回転方向に回転しながら第１屈曲部２０ａに侵入して停止する。また、シャフト１７に設けられた突起１９は、溝２０の第２端部に到達すると、第２回転方向に回転しながら第２屈曲部２０ｂに侵入して停止する。このため、突起１９が第１屈曲部２０ａ又は第２屈曲部２０ｂ内に位置するとき、雌ねじ１４ａと雄ねじ１７ａとの摩擦力は、シャフト１７が回転せずに停止される場合に比べて低減される。したがって、雌ねじ１４ａと雄ねじ１７ａとがロックされることを防止でき、突起１９が第１屈曲部２０ａ又は第２屈曲部２０ｂ内に位置する状態から反対方向に駆動されるとき、シャフト１７を迅速に移動することが可能である。 Moreover, according to the above embodiment, the groove 20 has the first bent portion 20a and the second bent portion 20b, and when the protrusion 19 provided on the shaft 17 reaches the first end portion of the groove 20, the groove 20 becomes the first. While rotating in one rotation direction, it invades the first bent portion 20a and stops. Further, when the protrusion 19 provided on the shaft 17 reaches the second end portion of the groove 20, it enters the second bent portion 20b while rotating in the second rotation direction and stops. Therefore, when the protrusion 19 is located in the first bent portion 20a or the second bent portion 20b, the frictional force between the female screw 14a and the male screw 17a is reduced as compared with the case where the shaft 17 is stopped without rotating. NS. Therefore, it is possible to prevent the female screw 14a and the male screw 17a from being locked, and when the protrusion 19 is driven in the opposite direction from the state where the protrusion 19 is located in the first bent portion 20a or the second bent portion 20b, the shaft 17 is quickly driven. It is possible to move.

さらに、本実施形態によれば、第１屈曲部２０ａ及び第２屈曲部２０ｂを設けることにより、モータ１２を停止させるタイミングを厳密に制御することなく、雌ねじ１４ａと雄ねじ１７ａとがロックされることを防止できる。このため、モータ１２の制御を容易化することが可能である。 Further, according to the present embodiment, by providing the first bent portion 20a and the second bent portion 20b, the female screw 14a and the male screw 17a are locked without strictly controlling the timing at which the motor 12 is stopped. Can be prevented. Therefore, it is possible to facilitate the control of the motor 12.

（第１変形例）
図６Ａは、第１の変形例を示すものであり、溝２０の上面を示している。第１変形例において、溝２０は、第１端部に第１屈曲部としての第１傾斜部２０ｄを有し、第２端部に第２屈曲部としての第２傾斜部２０ｅを有している。第１傾斜部２０ｄは、溝２０の第１端部の側面であり、この側面は、溝２０の直線部２０ｃに沿った側面に対して傾斜している。第２傾斜部２０eは、溝２０の第２端部の側面であり、この側面は、溝２０の直線部に沿った側面に対して傾斜し、第１傾斜部２０ｄと平行である。このため、溝２０の上方から見た形状は、平行四辺形である。 (First modification)
FIG. 6A shows a first modification and shows the upper surface of the groove 20. In the first modification, the groove 20 has a first inclined portion 20d as a first bent portion at the first end portion and a second inclined portion 20e as a second bent portion at the second end portion. There is. The first inclined portion 20d is a side surface of the first end portion of the groove 20, and this side surface is inclined with respect to the side surface along the straight portion 20c of the groove 20. The second inclined portion 20e is a side surface of the second end portion of the groove 20, and this side surface is inclined with respect to the side surface along the straight portion of the groove 20 and is parallel to the first inclined portion 20d. Therefore, the shape seen from above the groove 20 is a parallelogram.

上記構成において、シャフト１７が図２Ａに示す矢印Ａ方向に回転され、突起１９が第１端部から第２端部方向に移動するとき、突起１９は、矢印Ｃ方向に移動しようとする。このとき、突起１９に対して第１傾斜部２０ｄから垂直方向の力Ｐｘが作用する。この力Ｐｘは、突起１９の移動方向（矢印Ｃ）と一致しており、突起１９と第１傾斜部２０ｄとの間の摩擦力が低減される。このため、突起１９は、溝２０内を迅速に移動することが可能である。したがって、第１変形例によっても上記実施形態と同様の効果を得ることができる。 In the above configuration, when the shaft 17 is rotated in the direction of arrow A shown in FIG. 2A and the protrusion 19 moves from the first end to the second end, the protrusion 19 tends to move in the direction of arrow C. At this time, a force Px in the vertical direction acts on the protrusion 19 from the first inclined portion 20d. This force Px coincides with the moving direction of the protrusion 19 (arrow C), and the frictional force between the protrusion 19 and the first inclined portion 20d is reduced. Therefore, the protrusion 19 can move quickly in the groove 20. Therefore, the same effect as that of the above embodiment can be obtained by the first modification.

（第２変形例）
図７は、第２変形例を示すものであり、溝２０の上面を示している。第２変形例において、溝２０は、第１端部に第１屈曲部としての第１湾曲部２０ｆを有し、第２端部に第２屈曲部としての第２湾曲部２０ｇを有している。第１湾曲部２０ｆは、溝２０の第１端部の側面であり、この側面は、溝２０の直線部２０ｃに沿った側面に対して湾曲している。第２傾斜部２０eは、溝２０の第２端部の側面であり、この側面は、溝２０の直線部に沿った側面に対して湾曲している。 (Second modification)
FIG. 7 shows a second modification, and shows the upper surface of the groove 20. In the second modification, the groove 20 has a first curved portion 20f as a first bent portion at the first end portion and a second curved portion 20 g as a second bent portion at the second end portion. There is. The first curved portion 20f is a side surface of the first end portion of the groove 20, and this side surface is curved with respect to the side surface along the straight portion 20c of the groove 20. The second inclined portion 20e is a side surface of the second end portion of the groove 20, and this side surface is curved with respect to the side surface along the straight portion of the groove 20.

上記構成において、シャフト１７が図２Ａに示す矢印Ａ方向に回転され、突起１９が第１端部から第２端部方向に移動するとき、突起１９は、矢印Ｃ方向に移動しようとする。このとき、突起１９に対して第１湾曲部２０ｆから垂直方向の力Ｐｘが作用する。この力Ｐｘは、突起１９の移動方向（矢印Ｃ）と一致しており、突起１９と第１湾曲部２０ｆとの間の摩擦力が低減される。このため、突起１９は、溝２０内を迅速に移動することが可能である。したがって、第２変形例によっても上記実施形態と同様の効果を得ることができる。 In the above configuration, when the shaft 17 is rotated in the direction of arrow A shown in FIG. 2A and the protrusion 19 moves from the first end to the second end, the protrusion 19 tends to move in the direction of arrow C. At this time, a force Px in the vertical direction acts on the protrusion 19 from the first curved portion 20f. This force Px coincides with the moving direction of the protrusion 19 (arrow C), and the frictional force between the protrusion 19 and the first curved portion 20f is reduced. Therefore, the protrusion 19 can move quickly in the groove 20. Therefore, the same effect as that of the above embodiment can be obtained by the second modification.

上記第１変形例、及び第２変形例は、溝２０を例として説明した。しかし、溝に限定されるものではなく、図２Ｃに示すように、突部に傾斜部や湾曲部を用いることも可能である。 The first modification and the second modification have been described by taking the groove 20 as an example. However, the present invention is not limited to the groove, and as shown in FIG. 2C, it is also possible to use an inclined portion or a curved portion for the protruding portion.

その他、本発明は上記各実施形態そのままに限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で構成要素を変形して具体化できる。また、上記各実施形態に開示されている複数の構成要素の適宜な組み合わせにより、種々の発明を形成できる。例えば、実施形態に示される全構成要素から幾つかの構成要素を削除してもよい。さらに、異なる実施形態にわたる構成要素を適宜組み合わせてもよい。 In addition, the present invention is not limited to each of the above embodiments as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in each of the above embodiments. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

１１…ハウジング、１２…モータ、１３…減速機、１４…筒体、１４ａ…雌ねじ、１７…シャフト、１７ａ…雄ねじ、１９…突起、２０…溝（案内部）、２０ａ…第１屈曲部、２０ｂ…第２屈曲部、２０ｄ…第１傾斜部、２０ｅ…第２傾斜部、２０ｆ…第１湾曲部、２０ｇ…第２湾曲部、２１…突部。 11 ... Housing, 12 ... Motor, 13 ... Reducer, 14 ... Cylinder, 14a ... Female screw, 17 ... Shaft, 17a ... Male screw, 19 ... Projection, 20 ... Groove (guide), 20a ... First bending, 20b ... second bent portion, 20d ... first inclined portion, 20e ... second inclined portion, 20f ... first curved portion, 20 g ... second curved portion, 21 ... protrusion.

Claims

With the housing
With the motor provided in the housing
A cylinder that is rotated by the motor and has a female screw,
A shaft having a male screw that is partially screwed into the female screw of the cylinder,
With the protrusions provided on the shaft,
A guide portion provided in the housing along the shaft, guiding the protrusion, and having a bent portion bent obliquely with respect to the moving direction of the shaft at at least one end portion in the moving direction of the shaft.
A linear actuator characterized in that

The linear actuator according to claim 1, wherein the guide portion is a groove provided in the housing.

The groove has a straight portion along the moving direction of the shaft, a first bent portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. The first bent portion includes a second bent portion as described above, and the first bent portion includes a third side surface and a fourth side surface that are bent obliquely in the first direction with respect to the first side surface and the second side surface of the straight portion. It has a fifth side surface that is located between the third side surface and the fourth side surface and is inclined with respect to the straight portion, and the second bent portion is formed on the first side surface and the second side surface of the straight portion. On the other hand, it is located between the sixth side surface and the seventh side surface that are obliquely bent with respect to the second direction opposite to the first direction, and the sixth side surface and the seventh side surface, and is inclined with respect to the straight line portion. The linear actuator according to claim 2, wherein the linear actuator has an eighth side surface parallel to the fifth side surface.

The groove has a straight portion along the moving direction of the shaft, a first inclined portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. The first inclined portion is located between the first side surface and the second side surface of the straight portion, and is in the first direction with respect to the first side surface and the second side surface. It has an inclined third side surface, and the second inclined portion is located between the first side surface and the second side surface of the straight portion and has a fourth side surface parallel to the third side surface. 2. The linear actuator according to claim 2.

The groove has a straight portion along the moving direction of the shaft, a first curved portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. The first curved portion has a third side surface curved with respect to the first side surface and the second side surface of the straight portion, and the second curved portion is the first curved portion. The linear actuator according to claim 2, wherein the linear actuator has a side surface and a fourth side surface curved with respect to the second side surface.

The linear actuator according to claim 1, wherein the guide portion is a protrusion provided in the housing.

The protrusions are a straight portion along the moving direction of the shaft, a first bent portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. A second bent portion as a portion is provided, and the first bent portion includes a third side surface and a fourth side surface that are bent obliquely in the first direction with respect to the first side surface and the second side surface of the straight portion. A fifth side surface that is located between the third side surface and the fourth side surface and is inclined with respect to the straight portion, and the second bent portion is the first side surface and the second side surface of the straight portion. It is located between the sixth side surface and the seventh side surface that are obliquely bent with respect to the second direction opposite to the first direction, and the sixth side surface and the seventh side surface, and is inclined with respect to the straight line portion. The linear actuator according to claim 6, wherein the linear actuator has an eighth side surface parallel to the fifth side surface.

The protrusions are a straight portion along the moving direction of the shaft, a first inclined portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. A second inclined portion as a portion is provided, and the first inclined portion is located between the first side surface and the second side surface of the straight portion, and is in the first direction with respect to the first side surface and the second side surface. The second inclined portion is located between the first side surface and the second side surface of the straight portion, and has a fourth side surface parallel to the third side surface. 6. The linear actuator according to claim 6.

The protrusions are a straight portion along the moving direction of the shaft, a first curved portion as the bent portion provided at the first end portion of the straight portion, and the bent portion provided at the second end portion. A second curved portion as a portion is provided, the first curved portion has a third side surface curved with respect to the first side surface and the second side surface of the straight portion, and the second curved portion is the first curved portion. The linear actuator according to claim 6, further comprising a fourth side surface curved with respect to one side surface and the second side surface.