JP2006132712A - Linear clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear clutch which can hinder a reverse input in one way only and which has a simple structure and an inexpensive manufacturing cost. <P>SOLUTION: A conical cam face 3a provided in an outer diameter of an output member 3 is inclined to the outer diameter side in the opposite direction to a reverse input indicated by an arrow B which arises only in one direction and a plurality of balls as engagement elements are retained in the retainer and are pressed by a plate spring 7 in the engaging direction with the cam faces 1a, 3a and the retainer 6 is fixed to an input member 2 with a fixed pin 5 which is orthogonal to the input member 2. By inserting the fixed pin 5 into an axial direction gap opened in the through-hole 3b provided in the output member 3, the reverse input in one way only can be hindered so that the linear clutch having the simple structure and the inexpensive manufacturing cost can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear clutch that transmits input from an input member that linearly moves in an axial direction to an output member, but blocks reverse input from the output member to the input member.

  The linear clutch that transmits the input from the input member that moves linearly in the axial direction to the output member but blocks the reverse input from the output member to the input member is linear on the inner diameter side of the cylindrical fixing member. The moving input member and the output member are arranged on the same axis, and the input member and the output member are provided on the cam surface with a constant displacement in the axial direction provided on the inner diameter side of the fixed member and on the outer diameter side of the output member. It is connected by a clutch mechanism having an engaging member engaged with a cam surface inclined in the axial direction, and an input from the input member to the output member is transmitted, but a reverse input from the output member to the input member is blocked. There is something like that (see, for example, Patent Document 1).

  In the one described in Patent Document 1, the cam surface on the outer diameter side of the output member forms a wedge space in which both end portions in the axial direction are narrow between the cam surface of the fixing member and the both end portions are narrow. A pair of engagement elements are held in the wedge space by a cage, the pair of engagement elements are pressed in opposite directions by an elastic member, and an output member is connected to an input member connected to the cage with an axial clearance. By doing so, reverse input in both directions from the output member to the input member is blocked. In addition, the wedge space where both ends in the axial direction are narrow may be a wedge space where both ends are wide and the center in the axial direction is narrow.

Japanese Patent No. 2895509

  For devices that require blocking the reverse input from the output member to the input member as described above, such as a parking brake of an automobile that transmits input from the operation end to the working end with a rod or wire, or a clutch for switching a transmission, In many cases, a reverse input from the output member to the input member is generated only in one direction when the rod is pushed back from the working end or a wire is drawn into the working end.

  The linear clutch described in Patent Document 1 can be applied to a device in which such reverse input occurs only in one direction, but in order to cut off the reverse input in both directions, a wedge space narrowing in both axial directions is formed. Since there is a pair of engagement elements that engage with the cam surfaces that form the respective wedge spaces, the cam surface that forms one wedge space and the one engagement element that engages with the cam surfaces do not act. Due to the presence of the cam surface and the engagement element that do not act, there is a problem that the structure becomes complicated and the manufacturing cost increases.

  Therefore, an object of the present invention is to provide a linear clutch that can block reverse input in only one direction, has a simple structure, and is inexpensive to manufacture.

  In order to solve the above-described problems, the present invention has an input member and an output member that are linearly moved in the axial direction on the inner diameter side of a cylindrical fixing member, and the input member and the output member are arranged coaxially. A clutch mechanism having an engagement member engaged between an axially fixed cam surface provided on the inner diameter side of the fixed member and an axially inclined cam surface provided on the outer diameter side of the output member In a linear clutch that is connected to transmit the input from the input member to the output member but blocks the reverse input from the output member to the input member, the reverse input from the output member to the input member is unidirectional. The cam surface provided on the output member is inclined to the outer diameter side in the axial direction in a direction opposite to the reverse input, and the engagement element is used as a rolling element, and the rolling element is used as a cage. And hold it in the direction to engage with the cam surface. A structure is adopted in which the retainer is fixed to the input member with a fixing pin orthogonal to the input member, and the fixing pin is inserted into the through hole provided in the output member with an axial clearance. did.

  That is, the cam surface provided on the output member is inclined to the outer diameter side in the axial direction in the direction opposite to the reverse input generated in only one direction, and the engagement element is a rolling element, and the rolling element is held by the cage. The retainer is pressed by the elastic member in the direction to engage with the cam surface, and the cage is fixed to the input member with a fixing pin orthogonal to the input member, and an axial clearance is formed in the through hole provided in the output member. It is possible to provide a linear clutch with a simple structure and low manufacturing cost that can block reverse input in only one direction.

  When the fixing member is cylindrical and the rolling element is a ball, the inner cylindrical surface of the fixing member can be used as it is as a cam surface with constant displacement in the axial direction, and the manufacturing cost is simpler. Can be inexpensive.

  By making the balls made of ceramic, it is possible to prevent the balls from being electrically eroded or fretting.

  In the linear clutch of the present invention, the cam surface provided on the output member is inclined to the outer diameter side in the axial direction in the direction opposite to the reverse input generated in only one direction, and the engaging element is a rolling element. The retainer is held by an elastic member in a direction to engage with the cam surface, and the retainer is fixed to the input member with a fixing pin orthogonal to the input member, and the fixing pin is inserted into a through hole provided in the output member. Since it is inserted with an axial gap, reverse input in only one direction can be cut off, and the manufacturing cost can be reduced with a simple structure.

  When the fixing member is cylindrical and the rolling element is a ball, the inner cylindrical surface of the fixing member can be used as it is as a cam surface with constant displacement in the axial direction, and the manufacturing cost is simpler. Can be inexpensive.

  By making the balls made of ceramic, it is possible to prevent the balls from being electrically eroded or fretting.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show a first embodiment. This linear clutch is used in a device that transmits an input from an operation end to a working end with a rod, and linearly moves in the axial direction on the inner diameter side of a cylindrical fixing member 1 as shown in FIG. The input member 2 and the output member 3 are coaxially arranged, and are inclined in the axial direction provided on the outer diameter of the output member 3 and the cylindrical cam surface 1a having a constant displacement in the axial direction provided on the inner diameter of the fixing member 1. A plurality of balls 4 as engaging members that engage with the conical cam surface 3 a are held by a holder 6 fixed to the input member 2 by a fixing pin 5 orthogonal to the input member 2, and attached to the holder 6. Each of the balls 4 is pressed in a direction to engage with the cam surfaces 1a and 3a by the plate spring 7 as an elastic member, and the fixing pin 5 opens an axial clearance in the through hole 3b provided in the output member 3. Inserted. Each ball 4 is made of ceramic.

  Although not shown, the input member 2 and the output member 3 are guided in linear movement by a linear guide, and an input from the input member 2 indicated by an arrow A in FIG. The reverse input from the output member 3 that is transmitted to the working end via the rod and indicated by the arrow B due to the pushing back of the rod from the working end is blocked by a mechanism that will be described later.

  As shown in FIGS. 2 (a), 2 (b), and 2 (c), the fixing pin 5 is fitted into each of the through holes 2a and 6a provided in the input member 2 and the retainer 6 to form a ring-shaped retainer. 6, pockets 6b for storing the balls 4 are provided at equal intervals in the circumferential direction.

  As shown in FIGS. 3A and 3B, a hole 3 c into which the distal end portion of the input member 2 is slidably fitted is provided on the proximal end side of the output member 3, and the fixing pin 5 is in the axial direction. The through hole 3b to be inserted with a gap is provided to be orthogonal to the hole 3c. Further, the conical cam surface 3a is inclined toward the outer diameter side in the axial direction in the direction opposite to the reverse input indicated by the arrow B in FIG.

  Below, the mechanism of the transmission of the input from the input member 2 mentioned above and the interruption | blocking of the reverse input from the output member 3 are demonstrated based on FIG. 4 and FIG. As shown in FIG. 4A, when the input from the input member 2 acts in the direction of arrow A, the fixing pin 5 is pressed against the front surface side of the through hole 3b of the output member 3, and the fixing pin 5 is The input is transmitted to the output member 3 via At this time, as shown in FIG. 5A, the cage 6 moves linearly together with the input member 2 and moves in a direction in which the ball 4 engages with the cam surface 3a. Since the cam surface 3a escapes by moving linearly with the ball, the ball 4 is transmitted to the output member 3 without being engaged with the cam surfaces 1a and 3a.

  As shown in FIG. 4B, when the reverse input from the output member 3 acts in the direction of arrow B, if the output member 3 tries to move in the direction of arrow B, as shown in FIG. Further, since the cage 6 fixed to the input member 2 does not move, the ball 4 pressed by the leaf spring 7 is engaged with the cam surface 3a of the output member 3 and the cam surface 1a of the fixed member 1 to be moved. Then, the output member 3 is locked and the reverse input is blocked.

  4C, when the input member 2 is returned in the direction of the arrow C, the fixing pin 5 is pressed to the rear surface side of the through hole 3b of the output member 3 and output via the fixing pin 5. The member 3 is also returned in the same direction. At this time, the cam surface 3a of the output member 3 moves in the direction in which it engages with the ball 4, but the cage 6 also moves together with the input member 2 to release the ball 4 from the cam surface 3a. The input member 2 and the output member 3 are returned together in the direction of the arrow C without engaging with the cam surfaces 1a and 3a.

  6 to 8 show a second embodiment. This linear clutch is used in a device that transmits an input from an operation end to a working end with a wire, and its basic configuration is the same as that of the first embodiment. And the reverse input direction indicated by the arrow B are opposite to those of the first embodiment, and the inclination of the conical cam surface 3a provided on the outer diameter of the output member 3 is also opposite. Is different. In this embodiment, the input from the input member 2 indicated by the arrow A is transmitted to the working end via a wire connected to the tip of the output member 3, and is indicated by the arrow B accompanying the drawing of the wire into the working end. The reverse input from the output member 3 is blocked by a mechanism described later.

  Below, the mechanism of the transmission of the input from the input member 2 mentioned above and the interruption | blocking of the reverse input from the output member 3 are demonstrated based on FIG. 7 and FIG. As shown in FIG. 7A, when the input from the input member 2 acts in the direction of the arrow A, the fixing pin 5 is pressed against the rear surface side of the through hole 3b of the output member 3, and the fixing pin 5 is The input is transmitted to the output member 3 via At this time, as shown in FIG. 8A, the cage 6 moves linearly together with the input member 2 and moves in a direction in which the ball 4 engages with the cam surface 3a. Since the cam surface 3a escapes by moving linearly with the ball, the ball 4 is transmitted to the output member 3 without being engaged with the cam surfaces 1a and 3a.

  As shown in FIG. 7B, when the reverse input from the output member 3 acts in the direction of arrow B, if the output member 3 tries to move in the direction of arrow B, as shown in FIG. Further, since the cage 6 fixed to the input member 2 does not move, the ball 4 pressed by the leaf spring 7 is engaged with the cam surface 3a of the output member 3 and the cam surface 1a of the fixed member 1 to be moved. Then, the output member 3 is locked and the reverse input is blocked.

  7C, when the input member 2 is returned in the direction of the arrow C, the fixing pin 5 is pressed against the front surface side of the through hole 3b of the output member 3 and output via the fixing pin 5. The member 3 is also returned in the same direction. At this time, the cam surface 3a of the output member 3 moves in the direction in which it engages with the ball 4, but the cage 6 also moves together with the input member 2 to release the ball 4 from the cam surface 3a. The input member 2 and the output member 3 are returned together in the direction of the arrow C without engaging with the cam surfaces 1a and 3a.

  In each of the embodiments described above, the fixing member is cylindrical, and the rolling element as the engagement element is a ball. However, the rolling element can also be a roller. In this case, the fixing member is a rectangular tube. It can also be.

The longitudinal cross-sectional view which shows the linear clutch of 1st Embodiment a is a longitudinal sectional view showing the input member and the cage of FIG. 1, b is a sectional view taken along line IIb-IIb of a, and c is a sectional view taken along line IIc-IIc of a. a is a notched front view showing the output member of FIG. 1, and b is a plan view of a. a, b and c are longitudinal sectional views for explaining the operation mechanism of the linear clutch of FIG. a and b are cross-sectional views showing enlarged main portions of FIGS. 4 (a) and 4 (b), respectively. The longitudinal cross-sectional view which shows the linear clutch of 2nd Embodiment a, b, and c are longitudinal sectional views for explaining the operation mechanism of the linear clutch shown in FIG. a and b are cross-sectional views showing enlarged main portions of FIGS. 7A and 7B, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing member 1a Cam surface 2 Input member 2a Through hole 3 Output member 3a Cam surface 3b Through hole 3c Hole 4 Ball 5 Fixing pin 6 Cage 6a Through hole 6b Pocket 7 Leaf spring

Claims (3)

  On the inner diameter side of the cylindrical fixing member, the input member and the output member that move linearly in the axial direction are arranged coaxially, and these input member and output member are arranged in the axial direction provided on the inner diameter side of the fixing member. The input member is connected to the output member by a clutch mechanism having an engaging member that engages between a cam surface having a constant displacement and an axially inclined cam surface provided on the outer diameter side of the output member. In the linear clutch in which the reverse input from the output member to the input member is cut off, the reverse input from the output member to the input member occurs only in one direction and is provided in the output member. Assuming that the cam surface is inclined to the outer diameter side in the axial direction in the direction opposite to the reverse input, the engaging element is a rolling element, and the rolling element is held by a cage and engaged with the cam surface. Pressing with an elastic member, the cage is moved to the input section Linear clutch, characterized in that fixed to the input member in a fixed pin orthogonal to fitted to the fixing pins to open the axial clearance in the through hole formed in the output member and.   The linear clutch according to claim 1, wherein the fixing member is cylindrical, and the rolling element is a ball.   The linear clutch according to claim 2, wherein the ball is made of ceramic.

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