JP2007010001A - Axial one-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To add the function of a torque limiter to an axial one-way clutch which locks the unidirectional movement of a rod. <P>SOLUTION: The housing 1 has a conical face 3 on the inner periphery. A cage 5 is incorporated between the conical face 3 and the outer periphery of the rod 2 inserted into the housing 1, and a ball 7 is incorporated in a pocket 6 of the cage 5. An elastic member 10 energizes the cage 5 in the direction that the ball 7 abuts on the conical face 3 and the outer periphery of the rod 2. In the condition that the rod 2 is locked with the ball 7 engaging with the outer periphery of the rod 2 and the conical face 3 of the housing 1, when axial overload is applied to the rod 2, the rod 2 is plastically deformed at an engaging portion of the ball 7 in the radial direction and the rod 2 is moved to be locked in the condition that its deformed amount is held to generate the function of the torque limiter, thus preventing the breakage of the housing 1. By replacing the rod 2 with another rod 2 different in radial rigidity, a toque limiter load is selectively set. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an axial one-way clutch capable of locking a rod movable in the axial direction in one direction.

  Conventionally, this type of axial one-way clutch described in Patent Document 1 has been known. In this axial one-way clutch, a cylindrical inner surface is provided with a conical inner surface, and a plurality of engagement elements are incorporated at equal intervals in the circumferential direction between the inner surface of the cone and the cylindrical surface of the shaft inserted into the main body. The engaging element is pressed by a spring and urged toward the direction of engagement with the inner surface of the cone and the cylindrical surface of the shaft, and the shaft is locked in one direction by the engagement of the engagement element with the inner surface of the cone and the cylindrical surface. Like to do.

In addition, a cap is opposed to the end face of the main body, a solenoid is provided on the outer peripheral portion of the main body, a magnetic attraction is applied to the cap by energizing the solenoid, and the cap is moved toward the end face of the main body, and the cap is provided. The cylindrical body portion presses the engaging element in the axial direction to release the engagement of the engaging element.
JP 51-114553 A

  By the way, in the above-mentioned axial one-way clutch, if the surface hardness and rigidity of the main body and the shaft are approximately the same, when the shaft is loaded with an excessive load in the locking direction, the engagement element is strongly applied to the conical inner surface and the cylindrical surface. Biting and plastic deformation of both the conical inner surface and the cylindrical surface can render it unusable. Moreover, there is a possibility of damaging the clutch mounting part and the frame. As countermeasures, it is effective to increase the rigidity of each part, but there is a problem that the weight increases and the cost increases.

  An object of the present invention is to add a function as a torque limiter to an axial one-way clutch that can lock a rod in one axial direction to prevent damage to the housing, and to respond to a request for torque limiter load. Is to be able to set.

  In order to solve the above-mentioned problems, in the present invention, a rod is inserted into a fixed housing and arranged coaxially, and a conical surface inclined in the axial direction is provided on the inner periphery of the housing. A plurality of pockets are formed in a cage assembled between the conical surface and the outer periphery of the rod, and an engagement element is assembled in each pocket, and the engagement element is directed toward the direction in which the engagement element abuts on the conical surface and the outer periphery of the rod. An elastic member for biasing the cage is provided, the rod is cylindrical, and the plastic deformability is made higher than the plastic deformability of the housing, and there are several rods with different radial rigidity as the rod. The configuration is such that the rod is detachable from the housing.

  In the axial one-way clutch configured as described above, when an axial load in the locking direction is applied to the rod, the engaging element engages with the conical surface of the housing and the outer peripheral surface of the rod, and the rod is locked by the engagement. The

  In the locked state, when the axial load increases, the engaging element is pulled toward the small diameter end side along the conical surface of the housing. At this time, since the plastic deformability of the rod is higher than the plastic deformability of the housing, the rod is elastically deformed radially inward.

  If the axial load is an excessive axial load exceeding the elastic limit of the rod, the rod is plastically deformed, and the rod moves in the axial direction while maintaining the amount of radial deformation.

  In this way, when an excessive axial load is applied to the rod and the axial load exceeds a predetermined value, the rod moves in the axial direction in a plastically deformed state, and the movement is an action as a torque limiter. The effect of preventing damage to the housing and the mounting portion of the housing can be obtained.

  Here, since the amount of deformation in the radial direction of the rod depends on the radial rigidity of the rod, several types of rods having different radial rigidity are prepared, and the torque limiter is made detachable with respect to the inside of the housing. The limit load can be set arbitrarily.

  Examples of the rod having different radial rigidity include a cylindrical body in which a groove having an arcuate cross section is formed at a portion corresponding to the engaging element, and a polygonal cylindrical body corresponding to the number of engaging elements.

  As described above, in the present invention, when the rod is cylindrical and the plastic deformability is higher than the plastic deformability of the housing, when the rod is locked and an excessive axial load is applied, the rod Therefore, a function as a torque limiter can be added to the axial one-way clutch. For this reason, it is possible to prevent damage to the conical surface of the housing and the clutch mounting portion that supports the housing, and it is not necessary to increase the rigidity of the housing, thereby reducing the weight and cost.

  In addition, when the torque limiter functions, the rod must be replaced with a new rod. However, the rod is built in the housing and is freely movable in the direction in which the engagement element moves toward the large-diameter end of the conical surface. Therefore, the cost required for replacement can be reduced as compared with the case where both the rod and the housing are replaced.

  Furthermore, the limit load of the torque limiter can be arbitrarily set by making several types of rods having different radial rigidity detachable from the housing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a rod 2 is inserted inside a housing 1 that is in a fixed arrangement.

  A conical surface 3 is formed on the inner periphery of the housing 1, and an inward flange 4 is formed at one end of the conical surface 3 on the small diameter end side.

  A cage 5 is incorporated between the inner periphery of the housing 1 and the outer periphery of the rod 2. A plurality of pockets 6 are formed in the cage 5 at equal intervals in the circumferential direction, and balls 7 as engaging elements are incorporated in the pockets 6.

  As shown in FIG. 6, the rod 2 is formed of a cylindrical body, and the outer periphery of the rod 2 is formed with a circular arc-shaped groove 8 at a position corresponding to each ball 7, and the axial cross-sectional shape is a non-circular shape, In addition, the inner circumference is circular, and the plastic deformability in the radial direction is higher than the plastic deformability of the housing 1.

  As shown in FIG. 3, a retaining ring 9 that prevents the retainer 5 from coming off is attached to the inner periphery of the other end of the housing 1, and an elastic member 10 is incorporated between the retaining ring 9 and the retainer 5. . The elastic member 10 urges the cage 5 toward the flange 4 of the housing 1, and the ball 7 is brought into a lock standby state in which the ball 7 abuts against the conical surface 3 of the housing 1 and the bottom surface of the groove 8 of the rod 2. ing.

  The axial one-way clutch shown in the embodiment has the above-described structure. As shown in FIG. 3, in the lock standby state in which the ball 7 is in contact with the conical surface 3 of the housing 1 and the bottom surface of the groove 8 of the rod 2, When an axial force in the direction indicated by the arrow in the figure (the unlocking direction) is applied, the ball 7 moves toward the large-diameter end of the conical surface 3 formed on the housing 1, so the rod 2 is Move freely in the direction indicated by.

  Contrary to the above, when an axial force in the direction opposite to the direction indicated by the arrow (locking direction) is applied to the rod 2, the ball 7 engages with the conical surface 3 and the bottom surface of the groove 8. As a result, the rod 2 is locked and prevented from moving in the axial direction.

  When the axial force (axial load) in the locking direction increases in the locked state of the rod 2, the ball 7 is drawn to the small diameter end side of the conical surface 3.

  At this time, since the plastic deformability of the rod 2 in the radial direction is higher than the plastic deformability of the housing 1, the bottom surface of the groove 8 of the rod 2 is brought into the radial direction by the pressure of the ball 7 moving to the small diameter end side of the conical surface 3. Elastically deforms in the direction.

  When the axial load in the locking direction further increases and exceeds the elastic limit of the rod 2, the rod 2 is plastically deformed at the portion of engagement with the ball 7 as shown in FIG. As the value increases, the amount of plastic deformation of the rod 2 also increases. Reference numeral 11 denotes a plastic deformation portion of the rod 2.

  When the axial holding force of the rod 2 by the ball 7 reaches a predetermined value, the rod 2 moves in the axial direction while maintaining the plastic deformation ability in the radial direction as shown in FIG.

  FIG. 9 is a graph showing the relationship between the axial stroke and the axial holding force of the rod 2 of the axial one-way clutch in which the plastic deformability of the rod 2 is higher than the plastic deformability of the housing 1. In the graph, at the initial stage (I) of the excessive load action, the ball 7 is pushed into the bottom surface of the groove 8 of the rod 2 and the bottom surface of the groove 8 is elastically deformed radially inward. When the axial load further increases, the rod 2 is plastically deformed radially inward by the pressure of the ball 7, and the rod 2 moves in the axial direction while maintaining the amount of plastic deformation (II). In the region (II), a relatively flat load characteristic region a is obtained, and the function as a torque limiter is exhibited in this portion.

  As described above, by making the plastic deformability of the rod 2 higher than the plastic deformability of the housing 1, a function as a torque limiter can be added to the axial one-way clutch, and the conical surface 3 and the mounting portion of the housing 1 can be added. Can be prevented, and since it is not necessary to increase the rigidity, it is possible to reduce the weight and the cost.

  When the torque limiter functions, since the rod 2 is plastically deformed, it needs to be replaced with a new one. At this time, when the rod 2 is pressed in the unlocking direction (the direction indicated by the arrow in FIG. 3), the ball 7 moves to the large diameter end side along the conical surface 3 to release the holding of the rod 2. The cost required for replacement can be reduced as compared with the case where both the rod 2 and the housing 1 are replaced.

  Here, the limit load of the torque limiter is determined by the axial holding force of the rod 2. The axial holding force is substantially proportional to the amount of plastic deformation in the radial direction of the rod 2, and the amount of plastic deformation in the radial direction depends on the radial rigidity of the rod 2.

  For this reason, the limit load of the torque limiter can be arbitrarily set by controlling the amount of plastic deformation in the radial direction of the rod 2, that is, by exchanging the rod 2 with one having a different rigidity.

  In the embodiment, the rods 2 shown in FIGS. 6 to 8 are prepared, and the limit load of the torque limiter is set by replacing these rods 2.

Here, as described above, the rod 2 shown in FIG. 6 is provided with a groove 8 having an arcuate cross section at a portion corresponding to the outer ball 7 and a cylindrical surface 12 on the inner periphery.
It is stopped.

  Further, the rod 2 shown in FIG. 7 is provided with a groove 8 having an arc-shaped cross section at a portion corresponding to the ball 7 on the outer periphery, and the outer periphery is shaped like the inner periphery.

  Further, the rod 2 shown in FIG. 8 has a polygonal cylindrical shape corresponding to the number of balls 7.

  Since each of these rods 2 has an irregular shape whose outer periphery is not a circle, the rigidity in the radial direction is high, and the axial holding force of the rod 2 can be increased. Further, the rigidity in the radial direction is different for each rod 2, and the limit load of the torque limiter can be arbitrarily set by using these rods 2 by replacing them.

  Further, in order to change the radial rigidity of the rod 2, a means for uniformly increasing the thickness of the outer periphery having a circular shape is also conceivable. However, compared to the actual shape adopted in the embodiment, the weight increases. Become. That is, in the shape of the embodiment, the radial rigidity can be changed without increasing the weight.

  In addition, if it is a rod shape in which said objective is achieved, it will not be limited to the thing of embodiment.

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 drawing which shows the standby state of the axial direction one-way clutch shown in FIG. Sectional view showing the locked state with plastic deformation of the rod Sectional drawing which shows the operating state of the torque limiter added to the axial one-way clutch End view of rod End view showing another example of rod End view showing yet another example of rod Graph showing the relationship between rod shaft stroke and axial holding force

Explanation of symbols

1 Housing 2 Rod 3 Conical Surface 5 Cage 6 Pocket 7 Ball 8 Groove 10 Elastic Member

Claims (3)

  A rod is inserted into a fixed housing and arranged coaxially. A conical surface inclined in the axial direction is provided on the inner periphery of the housing, and the cage is built between the conical surface and the outer periphery of the rod. A plurality of pockets are formed in each pocket, and an engagement element is incorporated in each pocket, and an elastic member is provided to urge the retainer in a direction in which the engagement element abuts on the conical surface and the outer periphery of the rod. A cylindrical one-way plastic deformability that is higher than the plastic deformability of the housing. The rod has several types of rods with different radial rigidity, and these rods are detachable from the housing. clutch.   2. The axial one-way clutch according to claim 1, wherein the rod is formed of a cylindrical body in which a groove having an arcuate cross section is formed at a portion corresponding to the engagement element.   The axial one-way clutch according to claim 1, wherein the rod is formed of a polygonal cylinder corresponding to the number of engaging elements.

Images