JP5851816B2 - Reverse input cutoff clutch - Google Patents

Description

  The present invention relates to a reverse input cutoff clutch that transmits input torque from the input side to the output side and blocks reverse input torque from the output side.

  Conventionally, there has been known a reverse input cutoff clutch that transmits input torque from the input side to the output side and blocks reverse input torque from the output side. For example, in the reverse input cutoff clutch disclosed in FIG. 1 of Patent Document 1, the output shaft 23 (output side member) and the fixed outer ring 21 (fixed member) are arranged coaxially. A pair of rollers 30 a and 30 b are accommodated in a pocket 29 between the cam surfaces 31 a and 31 b constituting the outer wall of the output shaft 23 and the inner peripheral surface of the fixed outer ring 21. In addition, a wedge gap is formed at the circumferential end of the pocket 29. The pair of rollers are biased in the circumferential direction away from each other by springs 42 a and 42 b provided therebetween, and are pressed between the cam surfaces 31 a and 31 b and the fixed outer ring 21.

When reverse input torque from the load acts on the output shaft 23 with the input shaft 22 (input side member) stopped, the pair of rollers 30a and 30b is wedged between the cam surfaces 31a and 31b and the fixed outer ring 21. The rotation of the output shaft 23 is locked by entering the gap. As a result, the reverse input torque from the load is cut off and is not transmitted to the input shaft 22.
On the other hand, when the input shaft 22 rotates in the clockwise direction of FIG. 1, for example, the column portion 22b of the input shaft 22 pushes the roller 30a through the wedge gap, so that the lock is released and the output shaft 23 can rotate. As a result, torque from the input shaft 22 is transmitted to the output shaft 23.

By the way, the reverse input cutoff clutch of patent document 1 is the same as the direction of rotation of the input shaft 22 and the direction of reverse input torque when the lock is released by the rotation of the input shaft 22 from the locked state (reverse input cutoff state). If there is, the output shaft 23 starts to rotate by the reverse input torque. At this time, when the rotation of the output shaft 23 is faster than the rotation of the input shaft 22, the roller (30a or 30b) once pushed by the column portion 22b of the input shaft 22 enters the wedge gap again by the rotation of the output shaft 23, It becomes locked. Thereafter, the roller is repeatedly pushed out of the wedge gap by the input shaft 23 that continues to rotate, enters the wedge gap when the lock is released and the output shaft 23 starts to rotate.
In this way, a phenomenon in which the locked state and the unlocked state are repeated depending on the relative speed between the input shaft 22 and the output shaft 23 is referred to as a “catch-up lock phenomenon”. The catch-up lock phenomenon causes abnormal wear and noise of the reverse input cutoff clutch. Further, in a system in which a reverse input cutoff clutch is provided between the drive unit and the load and the rotation of the load is controlled by the drive unit, it becomes a factor that deteriorates controllability and responsiveness.

In view of this, a technique has been proposed in which rotational resistance is provided between an input shaft and an output shaft for the purpose of preventing the occurrence of a catch-up lock phenomenon in a usage situation where the directions of the reverse input torque and the input torque match. For example, the reverse input cutoff clutch of Patent Document 2 includes a wave washer between a retainer that rotates integrally with an input shaft and a presser lid (fixing member). Since the output shaft is pressed against the fixed member by the wave washer, the relative angle between the input shaft and the output shaft is maintained after the lock is released, and relocking (catch-up lock) is less likely to occur.
Moreover, the reverse input interruption | blocking clutch of patent document 3 has provided the wave spring of the compression state between the input member and the output member. The reverse input cutoff clutch of Patent Document 4 encloses a viscous fluid that imparts rotational resistance between an input shaft and an output shaft.

JP 2003-343601 A JP 2010-281375 A Japanese Patent Laid-Open No. 2004-19726 JP 2006-336838 A

In the techniques of Patent Documents 2 to 4, since a constant rotational resistance is always given by sliding of a wave washer or the like during rotation of the input shaft, torque loss during rotation increases.
The present invention was created in view of the above points, and an object of the present invention is to provide a reverse input cutoff clutch that reduces torque loss during rotation while preventing the occurrence of a catch-up lock phenomenon.

The reverse input cutoff clutch according to claim 1 includes a fixed member, an input shaft, an output shaft, a lock unit, a lock release unit, a torque transmission unit, and a relative angle maintaining unit.
The input shaft is connected to the drive unit, and drive torque is input from the drive unit.
The output shaft is connected to a load and outputs drive torque to the load.

The lock means locks the output shaft to the fixed member against the reverse input torque from the load in a neutral position with respect to the output shaft of the input shaft in a state where the drive torque is not input, so that the output shaft cannot be rotated.
The lock releasing means rotates integrally with the input shaft, and releases the locked state when the input shaft rotates beyond the first angle from the neutral position.
The torque transmission means transmits the driving torque from the input shaft to the output shaft when the input shaft further rotates a second angle larger than the first angle from the neutral position in the unlocked state by the lock releasing means.

The locking means is constituted by, for example, a pair of rollers corresponding to both forward and reverse rotations, and a roller lock spring that urges the pair of rollers in directions away from each other. Since the roller is sandwiched between the wedge-shaped spaces formed between the input shaft and the output shaft, the output shaft is locked so as not to rotate.
The unlocking means is constituted by, for example, a pillar portion formed in a cage that rotates integrally with the input shaft. When the input shaft is rotated beyond the first angle from the neutral position, the pillar portion pushes the roller out of the wedge portion to release the locked state.
The torque transmitting means is configured such that when the input shaft rotates by a second angle from the neutral position, the input shaft or a member that rotates integrally with the input shaft contacts the output shaft in the rotational direction.

The relative angle maintaining means maintains a relative angle of the input shaft to the output shaft in a torque transmission state by the torque transmitting means.
The relative angle maintaining means includes a receiving portion, an engaging member, and a biasing member.
The receiving portion is provided on one of the input shaft and the output shaft. The engaging member is provided on the other of the input shaft and the output shaft, and engages with the receiving portion at least in a torque transmission state. The urging member urges the engaging member in a direction to engage the receiving portion.

At least in the torque transmission state, the biasing member presses the engaging member against the receiving portion in a state where the engaging member is engaged with the receiving portion, so that a force is generated to hold the engaging member in that position. This force acts as a “holding force” that tries to maintain the relative angle of the input shaft to the output shaft.
As a result, even after the reverse input cutoff clutch is once in the torque transmission state, even if the rotational speed of the output shaft exceeds the rotational speed of the input shaft due to the reverse input torque, the torque difference between the output shaft and the input shaft is predetermined. If it is within the limit value, the input shaft can be prevented from being separated from the output shaft. Therefore, it is possible to prevent the catch-up lock phenomenon.

Further, the holding force during rotation from the neutral position to the start position of the torque transmission state (that is, the position rotated by the second angle) is the torque transmission state except for the rotational position where the engagement member engages the receiving portion. Less than the holding force at. Therefore, torque loss during rotation can be reduced as compared with the prior art in which rotation resistance is always given during rotation of the input shaft.
In addition to the starting position of the torque transmission state, the engaging member may be engaged with the receiving portion at the neutral position, and the holding force may be applied even at the neutral position.

Then, the torque transmission means includes a fitting shaft portion formed on one central axis of the input shaft or the output shaft and a fitting shaft portion formed on the other of the input shaft or the output shaft and relatively rotated within a predetermined angle range. It is comprised from the fitting hole which fits possible. Further, the relative angle maintaining means is provided across the outer wall of the fitting shaft portion and the inner wall of the fitting hole.

For example, the torque transmission means may be configured to form a planar outer wall and a planar inner wall facing each other in the fitting shaft portion and the fitting hole, and the planar outer wall abuts against the planar inner wall when the input shaft rotates by a predetermined angle. . Thereby, since the input shaft and the output shaft are connected on the central axis, the balance of the acting force is ensured by only one set of torque transmission means.
In this example, the convex curved outer wall excluding the planar outer wall of the fitting shaft portion and the concave curved inner wall excluding the planar inner wall of the fitting hole are not used for torque transmission. Therefore, by providing the relative angle maintaining means in these portions, it is possible to save space as compared with the case where the relative angle maintaining means is provided independently in other portions, which is advantageous for downsizing of the product. Furthermore, the processing location at the time of manufacture can be integrated and manufacturing man-hours can be reduced.

According to the second aspect of the present invention, the engaging member of the relative angle maintaining means is a ball, and the biasing member of the relative angle maintaining means is a spring. Thereby, the relative angle maintaining means can be realized with a simple configuration.
As another example, the engagement member itself may have elasticity and may also have a function as a biasing member. For example, an elastically deformable member such as a leaf spring, resin or rubber corresponds to this.

According to the third aspect of the present invention, the receiving portion of the relative angle maintaining means is constituted by a plurality of depressions. Moreover, the top part of the boundary of the dent adjacent to each other is formed in an edge shape.
Specifically, when a plurality of depressions are formed in a groove shape parallel to each other, the edge of the depression adjacent to each other has a ridge line that is a top portion as an edge-shaped peak. For example, if the engaging member is a ball, the ball goes up the slope from the bottom of the recess and reaches the ridge line of the mountain portion as the input shaft rotates. As soon as you get over the ridgeline, you slide down the slope toward the bottom of the adjacent pit. The rotational force of the input shaft is assisted by the downward movement of the ball. Therefore, the relative angle corresponding to the torque transmission state can be more reliably maintained by setting the position where the ball is received in the recess to be the position of the input shaft in the torque transmission state.

1 is an axial sectional view of a reverse input cutoff clutch according to a first embodiment of the present invention. (A) It is II-II line (radial direction) sectional drawing of FIG. 1 which shows the neutral state of a reverse input interruption | blocking clutch. (B) It is an enlarged view of a detent part. It is radial direction sectional drawing of the state which the input shaft rotated angle (alpha) from the neutral position. It is radial direction sectional drawing of the state which rotated the angle (beta) from the neutral position for the input shaft. It is a schematic diagram which shows the effect | action of a latch mechanism (relative angle maintenance means). It is explanatory drawing which shows the relationship between the rotation angle of an input shaft, and the force which acts on an input shaft. It is (a) radial direction sectional drawing which shows the neutral state of the reverse input interruption | blocking clutch by 2nd Embodiment of this invention, (b) The enlarged view of a detent part. It is radial direction sectional drawing which shows the neutral state of the reverse input interruption | blocking clutch by (a) 3rd Embodiment and (b) 4th Embodiment of this invention. It is an axial sectional view of a reverse input cutoff clutch according to a fifth embodiment of the present invention. FIG. 10 is a sectional view taken along line XX of FIG. 9 showing a neutral state of the reverse input cutoff clutch.

Hereinafter, a reverse input cutoff clutch according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
A reverse input cutoff clutch according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the reverse input cutoff clutch 101 of the first embodiment mainly includes an input shaft 11, a cage 12, an output shaft 21 in which a large-diameter inner ring 22 is integrally formed at an end portion, and a fixing member 30. , And rollers 41, 42 and the like.

The input shaft 11 and the output shaft 21 are provided coaxially on the central axis O. Hereinafter, the left side of the input shaft 11 in FIG. 1 is referred to as “input end side”, and the right side of the output shaft 21 is referred to as “output end side”.
The input shaft 11 is connected to a driving unit such as a motor (not shown), and driving torque is input from the driving unit. The output shaft 21 is connected to a load (not shown) and outputs drive torque to the load. Here, there is a possibility that reverse input torque is applied to the output shaft 21 from the load due to gravity or other force acting on the load.

  The reverse input cutoff clutch 101 locks the output shaft 21 so as not to rotate with respect to the reverse input torque so that the reverse input torque applied to the output shaft 21 is not transmitted to the input shaft 11. When the input shaft 11 rotates, the locked state of the output shaft 21 is released, and the torque of the input shaft 11 is transmitted to the output shaft 21.

2A, 3 and 4 are radial cross-sectional views taken along the line II-II in FIG. In this cross section, the input shaft 11 is shown as a fitting shaft portion 151, and the output shaft 21 is shown as an inner ring 22.
FIG. 2A shows a “neutral state” in which drive torque is not input to the input shaft 11. The position of the input shaft 11 in the neutral state is referred to as “neutral position”. A vertical line passing through the central axis O in FIG. 2A is referred to as a “neutral line N”.

  3 and 4 show a state in which a driving torque in the clockwise direction is input to the input shaft 11. Hereinafter, regarding the rotation direction of the input shaft 11, the clockwise rotation direction in the figure is referred to as “forward rotation direction” and the counterclockwise rotation direction in the figure is referred to as “reverse rotation direction”. FIG. 3 shows a state in which the input shaft 11 has rotated forward from the neutral position by the first angle α, and FIG. 4 shows a state in which the input shaft 11 has rotated forward from the neutral position by a second angle β that is greater than the first angle α. The meanings of the first angle α and the second angle β will be described later.

Subsequently, components of the reverse input cutoff clutch 101 will be described in order.
The input shaft 11 is coupled to the output shaft 21 by fitting a fitting shaft portion 151 formed on the central shaft O into the fitting hole 251 of the inner ring 22. In the fitting shaft portion 151, two convex curved outer walls 16 constituting a part of the outer diameter of the input shaft 11 and two planar outer walls 17 parallel to each other are formed symmetrically with respect to the central axis O. Further, the fitting shaft 151 is formed with a spring accommodating hole 181 that opens to the convex curved outer wall 16. This will be described later.

The cage 12 is joined to the input shaft 11 and rotates integrally with the input shaft 11. The cage 12 is provided with column portions 13 and 14 that are located in the radially outward direction of the output shaft inner ring 22 and project in the axial direction. The column portion 13 is provided on the reverse side with respect to the neutral line N, and the column portion 14 is provided on the normal rotation side with respect to the neutral line N.
The output shaft inner ring 22 has a polygonal column shape (in the present embodiment, a regular hexagonal column shape), and its outer wall forms the cam surface 23. The cam surfaces 23 are arranged at equal intervals in the circumferential direction.

A fitting hole 251 into which the fitting shaft portion 151 is inserted is formed in the center of the output shaft inner ring 22. The fitting hole 251 has two concave curved inner walls 26 facing the convex curved outer wall 16 of the fitting shaft portion 151 and four planar inner walls 27. The planar inner wall 27 is formed symmetrically with respect to the central axis O and symmetrical with respect to the neutral line N. The planar inner wall 27 is formed to be inclined by the second angle β with respect to the neutral line N so as to expand in the radially outward direction.
Thereby, the planar outer wall 17 of the fitting shaft portion 151 abuts against the planar inner wall 27 of the fitting hole 251 at a position where the input shaft 11 is rotated by the second angle β in both forward and reverse directions from the neutral position. In other words, the fitting shaft 151 is fitted in the fitting hole 251 so as to be relatively rotatable in an angle range of ± β.
Further, a detent portion 610 is formed on the concave curved inner wall 26 in the fitting hole 251. This will be described later.

The fixing member 30 is attached to a housing or the like (not shown) and is fixed to the drive unit and the load. The fixing member 30 includes a bearing holding portion 31, a disc portion 32, an outer ring 33, and a flange portion 34 that are integrally formed. The cylindrical bearing holding portion 31 holds the bearing 36 between the output shaft 21 and the radial direction. The bearing 36 is, for example, a “sintered impregnated bearing”. The disc portion 32 covers the axial output end side of the inner ring 22, and the cylindrical outer ring 33 covers the radially outward direction of the inner ring 22. In the flange portion 34, the end portion of the outer ring 33 is bent outward in the radial direction.
The presser lid 35 is fixed to the flange portion 34 of the fixing member 30 and covers the input end side of the cage 12 in the axial direction.

  A wedge-shaped space 49 is formed between the inner wall 331 of the outer ring 33 of the fixing member 30 and the cam surface 23 of the inner ring 22 and between the circumferential directions of the column portions 13 and 14. The wedge-shaped space 49 has a wedge shape in which the distance between the inner wall 331 of the outer ring 33 and the cam surface 23 gradually decreases at both ends in the circumferential direction.

The wedge-shaped space 49 accommodates a pair of rollers 41 and 42. The roller 41 is disposed on the reverse rotation side with respect to the neutral line N, and the roller 42 is disposed on the normal rotation side with respect to the neutral line N. A roller lock spring 43 that biases the rollers 41 and 42 apart from each other is interposed between the rollers 41 and 42. Accordingly, in the neutral position shown in FIG. 2, the rollers 41 and 42 are sandwiched between the wedge portions between the inner wall 331 of the outer ring 33 and the cam surface 23 and locked as indicated by a double arrow Rk. That is, since the inner ring 22 is locked with respect to the outer ring 33 (fixing member 30), the output shaft 21 cannot rotate, and the reverse input torque from the load is cut off.
Thus, the inner wall 331 of the outer ring 33, the cam surface 23, the pair of rollers 41 and 42, and the roller lock spring 43 constitute “locking means”.

In the “position where the input shaft 11 is rotated forward by the first angle α from the neutral position” shown in FIG. 3, the column portion 13 which has rotated forward as the input shaft 11 rotates contacts the side surface of the roller 41. From the neutral position to this position, the locked state by the roller 41 continues. On the other hand, when the input shaft 11 rotates forward beyond the first angle α from the neutral position, the column portion 13 pushes the roller 41 out of the wedge portion, thereby releasing the locked state. On the other hand, when the input shaft 11 rotates in the reverse direction, the column portion 14 pushes the roller 42 out of the wedge portion, so that the locked state is released.
Thus, the column parts 13 and 14 constitute “unlocking means”. The “first angle α” means a “lock release angle” at which the lock is released.

  Here, in FIGS. 2 to 4, only one set of “locking means and unlocking means” is shown, and other “locking means and unlocking means” are not shown. In the present embodiment, actually, six types of “locking means and unlocking means” are provided corresponding to each of the six cam surfaces 23.

By releasing the locked state, the output shaft 21 can rotate. When the input shaft 11 further rotates forward from the “neutral position to the position of the second angle β” shown in FIG. 4, the planar outer wall 17 of the fitting shaft portion 151 comes into contact with the planar inner wall 27 of the fitting hole 251. As a result, when the input shaft 11 rotates forward from the neutral position by the second angle β or more, the output shaft 21 rotates forward together with the input shaft 11, and the drive torque Ti from the input shaft 11 is transmitted to the output shaft 21 as the output torque To. The
Thus, the fitting shaft portion 151 and the fitting hole 251 constitute “torque transmission means”. The “second angle β” means “torque transmission start angle”.
When the input torque from the input shaft 11 disappears, the roller lock spring 43 returns to the neutral position shown in FIG.

Next, the latch mechanism that is a characteristic configuration of the present invention will be described in detail.
In this embodiment, the latch mechanism as the “relative angle maintaining means” includes a ball 51 as the “engaging member”, a spring 52 as the “biasing member”, and a detent portion 610 as the “receiving portion”. The
The convex curved outer wall 16 of the fitting shaft 151 is formed with a spring accommodation hole 181 that opens in the radially outward direction. The spring 52 is accommodated in the spring accommodation hole 181 between the ball 51 and the bottom. The spring 52 biases the ball 51 toward the opening side.

  On the other hand, as shown in FIG. 2B, a detent portion 610 is formed on the concave curved inner wall 26 of the fitting hole 251. The detent portion 610 includes three depressions 61R, 61N, and 61L that can receive the ball 51. In the present embodiment, the three recesses 61R, 61N, 61L are formed in a groove shape parallel to each other. In addition, a ridge 66 is formed at the boundary between the recess 61R and the recess 61N adjacent to each other and the recess 61N and the recess 61L. The ridge line that is the top of the peak portion 66 is formed in an edge shape.

In the neutral position shown in FIG. 2A, the ball 51 is received in the recess 61N by the urging force of the spring 52. When the fitting shaft portion 151 rotates forward by the second angle β, the ball 51 is received in the recess 61R (FIG. 4), and when the fitting shaft portion 151 rotates reversely by the second angle β, the ball 51 is received by the recess 61L.
Thus, in the present embodiment, the latch mechanism is provided across the convex curved outer wall 16 that is the outer wall of the fitting shaft 151 and the concave curved inner wall 26 that is the inner wall of the fitting hole 251. As a result, space can be saved as compared with the case where the latch mechanism is provided independently at other portions, which is advantageous for downsizing of the product. Furthermore, the processing location at the time of manufacture can be integrated and manufacturing man-hours can be reduced.

The operation of the latch mechanism (“relative angle maintaining means”) will be described with reference to FIG. Note that, in FIG. 5, for understanding of the explanation, the main parts such as the ball 51 and the recess 61 </ b> N are illustrated relatively larger than those in FIGS. 2 to 4.
FIG. 5A shows a state corresponding to FIG. 2, that is, a state in which the relative angle of the input shaft 11 to the output shaft 21 is held at the neutral position. At this time, the ball 51 is urged by the spring force Fsp with the bottom surface (shown by a thick line) of the recess 61N as a pressure receiving surface and engages with the recess 61N. This spring force Fsp becomes a “holding force Fk” for holding the input shaft 11 in the neutral position. In addition, the bottom (deepest point) of the recess 61N is an action point Pk of the holding force Fk.

  When an input torque in the forward rotation direction is input to the input shaft 11, the ball 51 goes up the slope from the bottom of the recess 61N toward the peak portion 66 against the holding force Fk. At this time, the action point Pk of the holding force Fk moves along the surface of the recess 61N. Then, as shown in FIG. 5B, immediately after the apex of the ball 51 gets over the edge-shaped ridgeline of the peak portion 66, the ball 51 is depressed by the resultant force of the spring Fsp and the rotational force Fr of the input shaft 11. Slide down the slope of 61R in the tangential tr direction. The ball 51 acts on the inner wall of the spring accommodating hole 181 to rotate the input shaft 11. In other words, the rotational force Fr of the input shaft 11 is assisted by the downhill movement of the ball 51, and the state immediately shifts to the state shown in FIG.

FIG. 5C shows a state corresponding to FIG. 4, that is, the input shaft 11 rotates by the second angle β from the neutral position, and the planar outer wall 17 of the fitting shaft portion 151 contacts the planar inner wall 27 of the fitting hole 251. A state in which the drive torque Ti is transmitted to the output shaft inner ring 22 in contact therewith is shown. At this time, the ball 51 is urged by the spring force Fsp with the bottom surface (shown by a thick line) of the recess 61R as a pressure receiving surface and is received in the recess 61R. This spring force Fsp becomes a “holding force Fk” that holds the input shaft 11 in the “transmission position”. In addition, the deepest point of the recess 61R becomes the action point Pk of the holding force Fk.
The operation described in FIGS. 5B and 5C is the same when the input shaft 11 reverses from the neutral position.

Thus, when the input shaft 11 rotates the second angle β in both the forward and reverse directions from the neutral position, the reverse input cutoff clutch 101 of the present embodiment has a relative angle of the input shaft 11 with respect to the output shaft 21 by the holding force Fk. Maintained. Therefore, if the output shaft 21 rotates faster than the input shaft 11 in the same direction as the input shaft 11 due to the reverse input torque after the locked state is released by the rotation of the input shaft 11 and the torque is transmitted, the output at that time If the torque difference between the shaft 21 and the input shaft 11 is within a predetermined limit value, the torque transmission state is maintained. Therefore, the occurrence of the “catch-up lock phenomenon” can be prevented.
Here, the predetermined limit value is determined by the holding force Fk. In other words, the torque based on the holding force Fk supplements the shortage of the driving torque with respect to the reverse input torque.

  When the torque difference between the reverse input torque and the drive torque exceeds a predetermined limit value, the torque transmission state is canceled. For example, when the input shaft 11 that has been rotating forward is suddenly braked and the drive torque is suddenly reduced, the reverse rotation torque of the output shaft 21 in the forward rotation direction relatively applies torque in the reverse rotation direction to the input shaft 11. The torque in the reverse direction pulls the planar outer wall 17 of the fitting shaft portion 151 away from the planar inner wall 27 of the fitting hole 251 against the holding force Fk in FIG. Then, the ball 51 is detached from the recess 61R and moved to the recess 61N, and the rollers 41 and 42 are locked, whereby the reverse input cutoff clutch 101 is in a neutral state.

  Further, it is assumed that the drive torque is switched from forward rotation to reverse rotation in the absence of reverse input torque from the load. In this case, the rotational force due to the driving torque in the reverse rotation direction pulls the planar outer wall 17 of the fitting shaft portion 151 away from the planar inner wall 27 of the fitting hole 251 against the holding force Fk in FIG. The torque transmission state of is released. Then, when the column portion 14 releases the lock of the roller 42 in the reverse direction through the neutral state, the ball 51 is received in the recess 61L and switched to the torque transmission state in the reverse direction.

Next, the relationship between the rotation angle θ of the input shaft 11 and the force acting on the input shaft 11 will be described with reference to FIG. The rotation angle θ on the horizontal axis represents the forward rotation angle as positive and the reverse rotation angle as negative.
As shown in FIG. 6A, in this embodiment, when the rotation angle θ of the input shaft 11 is 0 and ± β, the holding force Fk is maximized, and the rotation angle θ is between 0 and ± β. When the ball 51 gets over the mountain 66, the holding force Fk becomes the minimum (0). The holding force Fk is a force that maintains the relative angle between the input shaft 11 and the output shaft 21 and holds the torque transmission state. On the other hand, the rotational force Fr of the input shaft 11, contrary to the holding force Fk, is minimum (0) when the rotational angle θ is 0 and ± β, and the rotational angle θ is between 0 and ± β. It becomes maximum when the ball 51 gets over the mountain 66.

FIG. 6B shows a relationship between the rotation angle θ and the force in the prior art disclosed in Patent Documents 2 to 4 as a comparative example. In these conventional techniques, a constant rotational resistance Rr is always applied between the input shaft and the output shaft by sliding of a wave washer or the like while the input shaft is rotating. Therefore, the holding force Fk based on the rotation resistance Rr is also constant regardless of the rotation angle θ. In other words, since the holding force is always generated even when the holding force is not required, the torque loss increases.
On the other hand, in the present embodiment, the holding force Fk is maximized only at the three points of the neutral position and the torque transmission state start position in both the forward and reverse directions corresponding to the position where the rotation angle θ is ± β. Therefore, torque loss during rotation other than these points can be reduced.

(Second Embodiment)
Next, the reverse input cutoff clutch of 2nd Embodiment of this invention is demonstrated with reference to FIG. In the following description of the embodiment, the same reference numerals are given to substantially the same components as those in the first embodiment, and the description will be omitted.

  As shown to Fig.7 (a), the reverse input interruption | blocking clutch 102 of 2nd Embodiment has the structure of the input shaft 11 and the output shaft 21 which concern on a latch mechanism reverse to 1st Embodiment. Specifically, a spring accommodating hole 282 that opens in the radially inward direction is formed in the concave curved inner wall 26 of the fitting hole 252. The spring 52 is accommodated in the spring accommodation hole 282 between the ball 51 and the bottom. The spring 52 biases the ball 51 toward the opening side.

On the other hand, as shown in FIG. 7B, a detent portion 620 is formed on the convex curved outer wall 16 of the fitting shaft portion 152. The detent portion 620 includes three recesses 62R, 62N, and 62L that can receive the ball 51. In the neutral position shown in FIG. 7, the ball 51 is received in the recess 62 </ b> N by the urging force of the spring 52. When the fitting shaft portion 152 rotates forward by the second angle β, the ball 51 is received in the recess 62R. When the fitting shaft portion 152 rotates reversely by the second angle β, the ball 51 is received by the recess 62L.
The configuration of the lock unit and the lock release unit is the same as that of the first embodiment.

When the fitting shaft portion 152 of the input shaft 11 rotates by a second angle β in both forward and reverse directions from the neutral position, the planar outer wall 17 of the fitting shaft portion 152 abuts against the planar inner wall 27 of the fitting hole 252, and the input shaft 11. Can be transmitted to the output shaft 21. At the same time, the ball 51 provided on the output shaft inner ring 22 side passes over the peak portion 67 from the recess 62N and is received in the recesses 62R and 62L, so that the relative angle of the input shaft 11 with respect to the output shaft 21 is maintained. .
Thus, in the second embodiment, the ball 51, the spring 52, and the detent portion 620 correspond to “relative angle maintaining means”. As a result, as in the first embodiment, torque loss during rotation can be reduced while preventing the occurrence of the “catch-up lock phenomenon”.

(Third and fourth embodiments)
Next, the reverse input cutoff clutch of 3rd, 4th embodiment of this invention is demonstrated with reference to Fig.8 (a), (b). The reverse input cutoff clutches of the third and fourth embodiments are different from the first and second embodiments in the “engagement member” and the “biasing member” constituting the “relative angle maintaining means”. That is, the “engaging member” itself has elasticity and also functions as an “urging member”.

  As shown in FIG. 8A, the reverse input shut-off clutch 103 of the third embodiment includes three recesses 61R, 61N, and 61L on the concave curved inner wall 26 of the fitting hole 251 as in the first embodiment. A detent portion 610 is formed. Further, a spring seat portion 183 facing the detent portion 610 is formed on the convex curved outer wall 16 of the fitting shaft portion 153, and a leaf spring 53 bent in a V shape is attached to the spring seat portion 183. The leaf spring 53 is formed such that the bent portion 531 has a curvature corresponding to the depressions 61R, 61N, 61L of the detent portion 610.

  In the neutral position shown in FIG. 8A, the bent portion 531 of the leaf spring 53 is received in the recess 61N by the elastic force of the leaf spring 53 itself. When the fitting shaft portion 153 rotates, the leaf spring 53 is compressed and deformed in the height direction (shown by a broken line), so that the bending portion 531 can get over the peak portion 66. When the fitting shaft portion 153 rotates forward from the neutral position by the second angle β, the bending portion 531 is received in the recess 61R, and when the fitting shaft portion 153 reverses the second angle β, the bending portion 531 is received in the recess 61L.

  As shown in FIG. 8B, the reverse input cutoff clutch 104 of the fourth embodiment uses an elastically deformable member 54 such as resin or rubber instead of the leaf spring 53 of the third embodiment. The elastic deformation member 54 is accommodated in the accommodating portion 184 formed on the convex curved outer wall 16 of the fitting shaft portion 154. The elastic deformation member 54 is formed with a cavity 543 between the engagement portion 541 and the base portion 542, so that the engagement portion 541 can be elastically deformed in the vertical direction in the figure with respect to the base portion 542 (illustrated by a broken line).

In the neutral position shown in FIG. 8B, the engaging portion 541 of the elastic deformation member 54 is received in the recess 61N by the elastic force of the elastic deformation member 54. When the fitting shaft portion 154 rotates, the engaging portion 541 is elastically deformed with respect to the base portion 542, so that the mountain portion 66 can be overcome. When the fitting shaft portion 154 rotates forward from the neutral position by the second angle β, the engaging portion 541 is received in the recess 61R, and when the second angle β reverses, the engaging portion 541 is received in the recess 61L.
In the third and fourth embodiments, the same effects as those in the first and second embodiments can be obtained, and the number of parts constituting the “relative angle maintaining means” can be reduced as compared with the first and second embodiments. Can do.

(Fifth embodiment)
Next, the reverse input cutoff clutch of 5th Embodiment of this invention is demonstrated with reference to FIG. 9, FIG. In the reverse input cutoff clutch of the fifth embodiment, as in the first and second embodiments, a “relative angle maintaining means” is configured by a latch mechanism including the ball 51, the spring 52, and the detent portion 610. However, the latch mechanism is not provided across the outer wall of the fitting shaft portion and the inner wall of the fitting hole, but is provided independently of the fitting shaft portion and the fitting hole, and the spring 52 attaches the ball 51. It differs from the first and second embodiments in that the biasing direction is not the radial direction but the axial direction.

  As shown in FIGS. 9 and 10, the reverse input cutoff clutch 105 of the fifth embodiment is formed with an axial mechanism hole 285 in a portion independent of the fitting hole 255 of the output shaft inner ring 22. The mechanism hole 285 is an arc-shaped bottomed hole formed by rotating a round hole having a diameter capable of accommodating the ball 51 from the neutral line N in both the forward and reverse directions within a range of the second angle β. On the bottom surface of the mechanism hole 285, a detent portion 650 including three recesses 65R, 65N, and 65L is formed.

  Further, the retainer 12 is provided with a protrusion 125 at a position corresponding to the mechanism hole 285. The mechanism hole 285 accommodates the ball 51 at the bottom. The spring 52 is supported by the protrusion 125 of the cage 12 and biases the ball 51 toward the bottom surface side of the mechanism hole 285. When the spring 52 supported by the protrusion 125 of the cage 12 rotates integrally with the input shaft 11, the ball 51 moves following the spring 52. The ball 51 may be joined to the end of the spring 52 so as not to be detached from the end of the spring 52.

  The operation when the input shaft 11 rotates in both forward and reverse directions from the neutral position is the same as in the above embodiment. In the fifth embodiment, in addition to the same effects as in the above embodiment, the mechanism hole 285 is formed in a portion independent of the fitting hole 255, so that the degree of freedom in design regarding the size of the ball 51, the specifications of the spring 52, and the like is increased. Relatively high.

(Other embodiments)
(A) The detent portion 610 or the like as the “accepting portion” in the above embodiment includes three recesses, a recess corresponding to the torque transmission start position in both the forward and reverse directions, and a recess corresponding to the neutral position. In other embodiments, the “receiving portion” may not have a recess corresponding to the neutral position.
(A) The inner ring 22 is not limited to being provided integrally with the output shaft 21, but may be provided separately from the output shaft and rotatable integrally with the output shaft.

(C) In the above embodiment, the input shaft 11 is provided with the fitting shaft portion 151 and the like, and the output shaft inner ring 22 is provided with the fitting hole 251 and the like. Conversely, the output shaft may be provided with a fitting shaft portion, and the input shaft may be provided with a fitting hole.
(D) In the above embodiment, the fitting shaft portion 151 and the like formed on the central axis O and the fitting hole 251 and the like constitute the “torque transmission means”, so that the acting force can be achieved with only one set of torque transmission means. Balance is ensured. In other embodiments, the “torque transmission means” may be configured by a combination of a shaft and a hole formed in a portion other than the central axis O. In that case, it is desirable to secure a balance of acting force by arranging a plurality of “torque transmission means” symmetrically with respect to the central axis O.

(E) The configuration of the reverse input cutoff clutch other than the characteristic portion of the present invention is not limited to the configuration of the above embodiment. For example, the number of “locking means and unlocking means” represented by the number of cam surfaces 23 of the inner ring 22 is not limited to six.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

101-105 ... reverse input cutoff clutch,
11 ・ ・ ・ Input shaft,
12 ... Retainer,
13, 14... Pillar (lock release means),
151-155 ... fitting shaft (torque transmission means),
16 ... convex curved outer wall,
17 ... Planar outer wall,
181... Spring accommodating hole,
21 ... Output shaft,
22 ... Inner ring (output shaft inner ring),
23 ... Cam surface (locking means),
251-255 ... fitting hole (torque transmission means),
26 ... concave inner wall,
27 ・ ・ ・ Plane inner wall,
282, 285 ... spring accommodating hole,
30: Fixing member,
33 ・ ・ ・ Outer ring,
331 ... inner wall (outer ring) (locking means),
41, 42 ... rollers (locking means),
43 ... Roller lock spring (locking means),
49... Wedge-shaped space,
51... Ball (engagement member of relative angle maintaining means),
52... Spring (biasing member of relative angle maintaining means),
53... Leaf spring (engagement member and biasing member of relative angle maintaining means),
54 ... Elastic deformation member (engagement member and biasing member of relative angle maintaining means),
610, 620, 650 ... Detent part (receiving part of relative angle maintaining means),
61 (62, 65) R, 61 (62, 65) N, 61 (62, 65) L ... depression,
Fk: Holding power,
Fr ... rotational force,
Ti: Driving torque,
α ... 1st angle (lock release angle),
β 2nd angle (torque transmission start angle).

Claims (3)

A fixing member;
An input shaft connected to the drive unit and receiving drive torque from the drive unit;
An output shaft connected to a load and outputting a driving torque to the load;
In a neutral position of the input shaft with respect to the output shaft in a state in which drive torque is not input, the output shaft is locked to the fixed member against reverse input torque from the load, and the output shaft is brought into a locked state in which the output shaft cannot rotate. Locking means;
Unlocking means for rotating integrally with the input shaft, and for releasing the locked state when the input shaft rotates beyond a predetermined first angle from the neutral position;
Torque that transmits drive torque from the input shaft to the output shaft when the input shaft further rotates by a predetermined second angle greater than the first angle from the neutral position in the unlocked state by the unlocking means. A transmission means;
A relative angle maintaining means for maintaining a relative angle of the input shaft to the output shaft in a torque transmission state by the torque transmitting means;
With
The relative angle maintaining means is
A receiving portion provided on one of the input shaft and the output shaft;
An engagement member provided on the other of the input shaft and the output shaft and engaged with the receiving portion in at least the torque transmission state;
An urging member that urges the engaging member in a direction to engage the receiving portion;
Consisting of
The torque transmission means includes a fitting shaft portion formed on one central axis of the input shaft or the output shaft, and a fitting shaft portion formed on the other of the input shaft or the output shaft. And a fitting hole that fits in a relatively rotatable manner within a range,
The relative angle maintaining means, the reverse input blocking clutch according to claim Rukoto provided across the inner wall of the outer wall and the fitting hole of the fitting shaft portion. The reverse input cutoff clutch according to claim 1 , wherein the engaging member of the relative angle maintaining means is a ball, and the biasing member of the relative angle maintaining means is a spring. The receiving portion of the relative angle maintaining means is constituted by a plurality of depressions,
3. The reverse input cutoff clutch according to claim 1, wherein a boundary between the recesses adjacent to each other is formed in an edge shape at the top. 4.

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