JP2006077878A - Axial one-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial one-way clutch with a rod movable in two directions and lockable in one direction as required. <P>SOLUTION: A wedge space 8 is formed between the inner periphery of a housing 1 and the outer periphery of the rod 4 inserted through the inside thereof, and a conical roller 9 and a cage 10 for holding the conical roller 9 are incorporated in the wedge space 8. The elastic force of an elastic member 11 is imparted to the cage 10 to be energized to a narrow portion of the wedge space 8. A holding pin 21 is inserted into a pin hole 24 formed in the housing 1, and the holding pin 21 with one end put in engagement with an engaging portion 25 holds the conical roller 9 at a position of facing a wide portion of the wedge space 8. By electrifying an electromagnetic coil 23a of a electromagnet 23, the holding pin 21 is moved in the axial direction to cancel the engagement with the engaging portion 25. The cage 10 is moved to the narrow portion of the wedge space 8 by the elastic member 11. The conical roller 9 meshes with the narrow portion of the wedge space 8 to lock the rod 4 in one direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an axial one-way clutch which can prevent movement in one direction of a reciprocable rod as required.

Conventionally, an axial one-way clutch described in Patent Document 1 has been known. This one-way clutch in the axial direction is provided with a tapered surface having a large diameter end at the opening end of the cylinder formed in the body, and the rear end portion is slidably inserted into the tapered surface and the cylinder. A ball and a retainer for holding the ball are assembled between the outer peripheral cylindrical surfaces of the rods, and a spring force of a compression spring is applied to the retainer so that the balls are pressed against the tapered surface of the cylinder and the outer peripheral cylindrical surface of the rod. When the pushing force is applied to the rod, the ball is engaged with the tapered surface of the cylinder and the outer cylindrical surface of the rod to lock the rod.
Japanese Patent Publication No. 56-53139

  By the way, in the one-way clutch in the axial direction described in Patent Document 1, the ball is in a standby state in which the ball is pressed against the tapered surface of the cylinder and the outer cylindrical surface of the rod by the spring force of the compression spring, and the pushing force is applied to the rod. If this is done, the ball will immediately engage and the rod cannot be moved in the pushing direction.

  As described above, the one-way clutch in the axial direction is configured to lock the rod in one direction and freely move in the other direction of the rod, and therefore can be used only for special applications such as a chain tensioner. The range of applications is narrow, for example, the arm and foot of an industrial robot, or the parking brake mechanism of an electric brake, so that the rod can be moved in both directions and can be locked in one direction only when necessary. It is not possible to adopt it for the devices.

  An object of the present invention is to provide an axial one-way clutch in which a rod is movable in both axial directions and can be locked in one direction when necessary.

  In order to solve the above-described problems, in the present invention, one end in the axial direction is narrow between the inner periphery of the housing that is fixedly arranged and the outer periphery of the rod that is inserted into the housing and is movable in the axial direction. A wedge-shaped space is formed, and an engagement element and a holder for holding the engagement element are incorporated in the wedge-shaped space, and the engagement element is directed toward a narrow portion of the wedge-shaped space by an elastic member. Electromagnetic control for urging in the moving direction and holding the retainer at the disengagement position where the engaging element faces the wide portion of the wedge-shaped space in the housing and releasing the holding by energizing the electromagnetic coil A configuration provided with a formula holding means was adopted.

  Here, the engagement element may be a tapered roller or a ball. Moreover, a cylindrical roller may be sufficient.

Further, as the electromagnetic control type holding means, the following (1) and (2) can be adopted.
Holding means (1): slidably passes through the housing in the radial direction, and engages the cage by engagement between one end facing the narrow portion of the wedge-shaped space and the engaging portion provided at the end of the cage. The holding pin that holds the release pin, the spring that biases the holding pin toward the inside of the housing, and the armature attached to the other end of the holding pin are opposed to the armature by energizing the electromagnetic coil. It consists of an electromagnet that moves the holding pin radially outward of the housing.
Holding means (2): slidably passes through the housing in the radial direction, and engages the cage by engagement between one end facing the narrow portion of the wedge-shaped space and the engaging portion provided at the end of the cage. One end of a swingable lever is connected to the other end of the holding pin opposite the engaging portion, and the other end of the lever is energized by an electromagnetic coil. A linear motion type actuator that adsorbs the armature is coupled by the lever, and the holding pin is engaged with the engaging part of the cage with the position shifted from the central part in the length direction of the lever toward the other end as a swing center. Consists of a structure in which the lever is urged by an elastic member in the mating direction.

  In the one-way clutch having the above-described configuration, the retainer is held at the disengagement position by the holding means, so that the engagement element is held in the wide portion of the wedge-shaped space, so that the rod can be moved in both directions. be able to. Further, when releasing the holding of the cage by the holding means, the retainer moves toward the narrow portion of the wedge-shaped space by the pressing by the elastic member, and the engagement element bites into the narrow portion of the wedge-shaped space. Movement in one direction can be prevented, and a rod movable in both directions can be locked in one direction as required.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the housing 1 has a cylindrical shape. An end plate 2 is integrally provided at one end, and an annular plate 3 is attached to an opening at the other end by means such as press fitting.

  The rod 4 inserted into the housing 1 is supported by a bearing 5 attached to the end plate 2 so as to be movable in the axial direction.

  A cylindrical surface 6 is provided on the outer periphery of the rod 4, while a cam surface 7 formed of a conical surface is formed on the inner periphery of the housing 1, and one end in the axial direction is provided between the cam surface 7 and the cylindrical surface 6. A narrow wedge-shaped space 8 is formed.

  Inside the wedge-shaped space 8, a plurality of tapered rollers 9 as engagement elements and a cage 10 that holds the tapered rollers 9 are incorporated. The retainer 10 is urged in a direction in which the tapered roller 9 moves toward the narrow portion of the wedge-shaped space 8 by an elastic member 11 incorporated between the retainer 10 and the annular plate 3.

  The housing 1 is provided with electromagnetically controlled holding means 20 that holds the retainer 10 at a release position where the tapered roller 9 is disengaged from the cylindrical surface 6 and the cam surface 7.

  The holding means 20 includes a holding pin 21, a spring 22 that presses the holding pin 21 in the axial direction, and an electromagnetic coil 23a. The holding pin 21 is held against the elasticity of the spring 22 by energization of the electromagnetic coil 23a. The holding pin 21 is slidably inserted into a pin hole 24 in the radial direction from the outer peripheral surface of the housing 1 to the narrow portion of the wedge-shaped space 8. One end facing the narrow portion can be engaged with an engaging portion 25 formed of a notch formed on the outer periphery of the end of the retainer 10, and the tapered roller 9 is formed into a cylindrical shape by the engagement with the engaging portion 25. The retainer 10 is held at the disengagement position where the engagement with the surface 6 and the cam surface 7 is disengaged.

  Note that the end face of the cage 10 may be the engaging portion 25 and the cage 10 may be held at the release position by the engagement of the holding pin 21 with the engaging portion 25.

  A portion of the holding pin 21 facing the outside of the housing 1 is provided with an armature 26 made of a magnetic material, and the electromagnet 23 is disposed opposite to the armature 26.

  The electromagnet 23 is incorporated in a case 27 made of a nonmagnetic material attached to the outer periphery of the housing 1. Further, the spring 22 is incorporated in the case 27, and the spring 22 biases the holding pin 21 toward the inside of the housing 1.

  The axial one-way clutch shown in the embodiment has the above-described structure, and FIGS. 1 and 2 show a state in which the holding pin 21 is engaged with the engaging portion 25 of the cage 10 and the engaged state. Thus, the tapered roller 9 is held in a disengaged state with respect to the cylindrical surface 6 and the cam surface 7.

  Therefore, the rod 4 can move in two axial directions (left and right in FIG. 1).

  As shown in FIGS. 1 and 2, when the electromagnetic coil 23a of the electromagnet 23 is energized in a state where the cage 10 is held at the disengagement position, a magnetic attractive force acts on the armature 26, and FIG. As shown in FIG. 4, the armature 26 is attracted to the electromagnet 23 and the holding pin 21 moves outward in the radial direction of the housing 1, so that the engagement with the engaging portion 25 is released. By releasing the engagement, the retainer 10 is moved toward the narrow portion of the wedge-shaped space 8 by the pressing of the elastic member 11, and the tapered roller 9 is engaged with the cylindrical surface 6 and the cam surface 7, and the rod 4 is locked. Thus, movement in one direction (the opposite direction indicated by the arrow in FIG. 3) is prevented.

  When the pressing force in the direction indicated by the arrow is applied to the rod 4, the tapered roller 9 moves toward the wide portion of the wedge-shaped space 8, so that the rod 4 can move only in the direction indicated by the arrow. .

  Thus, since the rod 4 can be locked in one direction by energizing the electromagnetic coil 23a of the electromagnet 23, the rod 4 movable in both directions can be locked in one direction as necessary.

  In order to return the tapered roller 9 to the disengaged state, the energization of the electromagnetic coil 23 a is interrupted, and the rod 4 is moved in a state in which the holding pin 21 is urged toward the outer periphery of the cage 10 by the spring force of the spring 22. 3, the cage 10 is moved toward the wide portion of the wedge-shaped space 8 by the frictional resistance acting on the contact portion between the cylindrical surface 6 of the rod 4 and the tapered roller 9. One end is engaged with the engaging portion 25.

  In order to surely reset the cage 10 as described above, an actuator is provided on the end plate 2 side of the housing 1, and the actuator 10 is pushed toward the wide portion of the wedge-shaped space 8 by the actuator. Good.

  In the embodiment, the tapered roller 9 is shown as the engagement element, but the engagement element is not limited to this. For example, it may be a ball or a cylindrical roller. When a cylindrical roller is used as an engagement element, the cylindrical roller is arranged so that its axis is perpendicular to the axial direction of the rod 4, and faces the inner periphery of the housing 1 and the outer periphery of the rod 4 in the radial direction of the housing 1. A pair of flat surfaces is formed, and one of the pair of flat surfaces is inclined in the axial direction of the rod 4 to form a wedge-shaped space between the pair of flat surfaces.

  In the embodiment, the cylindrical surface 6 is formed on the outer periphery of the rod 4 and the cam surface 7 formed of a conical surface is formed on the inner periphery of the housing 1. However, the cylindrical surface is formed on the inner periphery of the housing 1 and the rod A cam surface may be provided on the outer periphery of 4.

  5 and 6 show another example of the holding means 20. The holding means 20 shown in FIGS. 5 and 6 has one end of a lever 28 connected to the end of the holding pin 21 inserted into the pin hole 24 of the housing 1 that faces the outside of the housing 1, and the length of the lever 28. A position offset from the center in the direction toward the other end is supported by a support piece 29 provided on the outer periphery of the housing 1 via a support pin 30 so as to be swingable. A plunger 32 of an electromagnet 31 is provided at the other end of the lever 28. The lever 28 is biased in the direction in which the holding pin 21 is engaged with the engaging portion 25 of the cage 10 by the elastic member 33 that is coupled and supported by the support pin 30, By energizing, the armature 34 integrated with the plunger 32 is attracted to the electromagnetic coil 31a, so that the lever 28 is swung and held so that the holding pin 21 moves to the outside of the housing 1. And so as to release the engagement between the engaging portion 25 of the emission 21 and the retainer 10 (see FIG. 6).

  In adopting the holding means 20 as well, the rod 4 can be locked in one direction as required, and a small electromagnet 31 with a small stroke amount of the plunger 32 and the armature 34 can be employed.

  In FIG. 5, the holding pins 21 and the electromagnets 31 are arranged in the axial direction of the housing 1. However, as shown in FIG. 7, the holding pins 21 and the electromagnets 31 may be arranged in the circumferential direction of the housing 1. .

A longitudinal front view showing an embodiment of an axial one-way clutch according to the present invention Sectional view along the line II-II in FIG. Sectional view showing the locked state of the rod Vertical side view of FIG. Sectional drawing which shows the other example of a holding means Sectional view showing the locked state of the rod Sectional drawing which shows the further another example of a holding means

Explanation of symbols

1 housing 8 wedge-shaped space 9 tapered roller (engagement element)
DESCRIPTION OF SYMBOLS 10 Cage 11 Elastic member 20 Holding means 21 Holding pin 22 Spring 23 Electromagnet 23a Electromagnetic coil 25 Engaging part 26 Armature 28 Lever 31 Electromagnet 33 Elastic member

Claims (4)

  A wedge-shaped space in which one end in the axial direction is narrowed is formed between the inner circumference of the fixed housing and the outer circumference of the rod that is inserted into the housing and is movable in the axial direction. An engaging member and a retainer for holding the engaging member, and the retainer is urged by an elastic member in a direction in which the engaging member moves toward the narrow portion of the wedge-shaped space. An axial one-way clutch provided with an electromagnetically controlled holding means for holding the retainer at an engagement release position where the engagement element faces the wide portion of the wedge-shaped space and releasing the holding by energizing the electromagnetic coil.   The axial one-way clutch according to claim 1, wherein the engagement member is made of one of a tapered roller, a ball, and a cylindrical roller.   The electromagnetic control type holding means penetrates the housing so as to be slidable in the radial direction, and engages with an engagement portion provided at an end portion of the cage and an end portion facing a narrow portion of the wedge-shaped space. The holding pin that holds the holding pin in the disengaged position, the spring that biases the holding pin toward the inside of the housing, and the armature attached to the other end of the holding pin are opposed to the armature by energizing the electromagnetic coil. The axial one-way clutch according to claim 1 or 2, comprising an electromagnet that attracts and moves the holding pin radially outward of the housing.   The electromagnetic control type holding means penetrates the housing so as to be slidable in the radial direction, and engages with an engagement portion provided at an end portion of the cage and an end portion facing a narrow portion of the wedge-shaped space. Has a holding pin that holds it in the disengaged position, and one end of a swingable lever is connected to the other end of the holding pin opposite the engaging portion, and the other end of the lever has an electromagnetic coil The linear motion actuator that attracts the armature by energizing the armature is connected, and the holding pin is engaged with the engaging portion of the cage with the position that is offset from the central portion in the length direction of the lever toward the other end. The axial one-way clutch according to claim 1 or 2, comprising a configuration in which a lever is urged by an elastic member in a direction of engagement.

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