JP2011133028A - Torque regulation type torque limiter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain regulated initial rotational torque, by restraining a shield member from rotating by the relative rotation of an inner ring member to a housing member. <P>SOLUTION: The shield member 6 includes a screw part 6B screwed into a threaded part 1B of the housing member 1, a pressing force imparted to a torque generation member by an elastic member 5 is regulated by rotating relatively the shield member 6 with respect to the housing member 1, to regulate the rotational torque Ta, a rotation restraining member 7 or a rotation restraining 6G of the shield member 6 restrains the shield member 6, after regulating the rotational torque Ta, and the initial rotational torque Ta after regulation is continuously maintained thereby. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a torque limiter capable of adjusting the rotational torque, and more particularly to a rotational torque limiter capable of maintaining the adjusted rotational torque without being affected by the rotation of an inner ring member.

  The torque limiter is generally widely used in a printer such as an OA device, a paper feeding, conveying, and discharging mechanism of a copying machine. The torque limiter is roughly classified into a contact type that obtains a desired rotational torque by mechanical friction and a non-contact type torque limiter that obtains a desired rotational torque using the magnetic force of a permanent magnet. Currently, most of the torque limiters used are contact type from the viewpoint of low cost, and various structures have been proposed. Since the present invention is an improvement of a contact type torque limiter, a conventional main contact type torque limiter will be described.

  As a main contact type torque limiter, there is a type in which a coil spring is wound around an inner ring member or a shaft and a rotational torque generated between the inner ring member or shaft and the coil spring is used (for example, see Patent Document 1). . Further, a curved member such as a ball or a roller and a member that uses a rotational torque generated between the curved surface by applying pressure to the curved surface (see, for example, Patent Document 2), or a cylindrical housing member and the like There is one that uses a rotational torque generated between the elastic friction member press-fitted therein (for example, see Patent Document 3).

  Furthermore, a torque limiter (for example, using a rotational torque generated between the shaft and the leaf spring member by tightening the shaft with various shapes of leaf spring members wound around the columnar or cylindrical shaft, for example, , See Patent Documents 4 to 6), a torque limiter (for example, refer to Patent Document 7) made of a spring member having a special shape that generates rotational torque between the shaft and the shaft, and the shaft is different in size. There has already been proposed a vibration absorption type torque limiter composed of a plurality of housing members that generate rotational torque and a housing that holds the housing members so as to move within a predetermined range (see, for example, Patent Document 8).

  These torque limiters are torque limiters that directly utilize the rotational torque generated between the shaft (inner ring member) and the spring member during assembly, and have a structure in which the magnitude of the rotational torque cannot be adjusted during assembly. However, in actual precision equipment, the rotational torque of all torque limiters may have to be within a range of + −several% of the set torque value required by the customer. In such a case, it is difficult to cope with a torque limiter having a structure in which the rotational torque is fixed. Therefore, a structure in which the rotational torque can be adjusted when the torque limiter is assembled has been proposed (for example, Patent Document 9, 10).

  The torque limiter disclosed in Patent Document 9 includes a torque generator that generates rotational torque, a spring member, and a torque adjustment member. By rotating the torque adjustment member, the spring member is contracted and applied to the torque generator. The rotational torque is adjusted by changing the pressure. Although the torque limiter described in Patent Document 10 is also different in the specific structure of the torque generator, the mechanism for adjusting the rotational torque has the same structure. In these torque limiters that can adjust the rotational torque, the torque adjustment member is rotated in the torque adjustment process after assembly to adjust the rotational torque, and when the set rotational torque is obtained, the rotation of the torque adjustment member is stopped. . In a state where the torque limiter is not used, the adjusted initial rotational torque is maintained and does not change.

  However, it has been found that when the torque limiter is also in a state where the inner ring member or the outer ring member rotates, the rotational torque of the torque limiter changes from the initial rotational torque. In particular, the tendency to change in a direction in which the rotational torque decreases is remarkable. This indicates that when the inner ring member and the outer ring member rotate relative to each other, the torque adjustment member that is the shield member is displaced or rotated by an angle under the influence of the rotation and vibration. I found out what happens because it moves in the axial direction.

  More specifically, in the torque limiter, the torque adjustment member acts as a shield member (lid) that closes one end side of the inner ring member, and the inner ring member is a side wall portion of the outer ring member (housing member) and the torque adjustment member. It is supported by (and supported by) and rotates. When the inner ring member rotates together with the rotation shaft of the device (not shown), naturally, a frictional force is generated between the torque adjusting member and the inner ring member, and the frictional force is larger depending on the vibration during rotation. Therefore, the torque adjustment member rotates from the initial position after torque adjustment due to the friction and shifts in the axial direction, thereby changing the rotational torque. It has been found that the torque adjusting member is always pushed outward by the elastic force of the spring member, so that it tends to shift outward, that is, in the direction of decreasing the rotational torque.

JP 2000-352427 A Japanese Patent Laid-Open No. 9-4650 Japanese Patent Laid-Open No. 09-112568 JP 2005-337472 A JP 2005-315329 A JP 2003-65355 A JP 10-131980 A JP 2005-291293 A JP-A-8-247163 JP 2009-192061 A

  The problem to be solved by the present invention is that a conventional torque limiter that is adjusted to have a predetermined rotational torque with a shield member that functions as a torque adjustment member is relatively between the inner ring member and the housing member. When the rotation is being performed, the shield member is displaced due to the frictional force or vibration during the rotation, so that the adjusted initial rotational torque value changes.

  In order to solve the conventional problems, the present invention provides a housing member having a threaded portion on an open inner surface on one end side, a shield member having a threaded portion screwed into the threaded portion of the housing member, and a housing member An inner ring member that is supported (axially supported) by the side wall portion and the shield member and is rotatable relative to the housing member, first and second torque generating members that generate an adjustable rotational torque Ta, and An elastic member that applies a pressing force to the torque generating member; and a rotation suppression member that prevents the shield member from rotating due to the influence of relative rotation between the inner ring member and the housing member, and the threaded portion and the screw portion. The elastic member adjusts the pressing force applied to the torque generating member by rotating the shield member relative to the housing member using After adjustment of the pressing force, rotation inhibiting member to prevent rotation of the shield member, proposes a torque limiter for maintaining the rotational torque of the adjusted initial.

  According to the present invention, during the operation of the torque limiter, the torque adjustment member does not shift or rotate from its initial position due to its rotation or vibration, so the rotational torque set at the initial stage of the torque limiter changes. There is nothing and it is held at a constant value.

It is drawing which shows each member before the assembly of the torque limiter which concerns on Embodiment 1 of this invention. It is a figure which shows the torque limiter which concerns on Embodiment 1 of this invention. It is a front view for demonstrating the housing member of the torque limiter which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the shield member of the torque limiter which concerns on Embodiment 2 of this invention. It is a figure which shows an example of the rotation suppression member used for the torque limiter which concerns on Embodiment 2 of this invention. It is a figure which shows the state which incorporated the rotation suppression member in the housing member of the torque limiter which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the torque limiter which concerns on Embodiment 3 of this invention. It is a figure which shows each member before the assembly of the torque limiter which concerns on Embodiment 4 of this invention. It is a figure which shows the torque limiter which concerns on Embodiment 4 of this invention. It is a figure which shows each member before the assembly of the torque limiter which concerns on Embodiment 5 of this invention. It is a figure which shows the torque limiter which concerns on Embodiment 5 of this invention. It is a figure which shows another example of the torque generation part of the torque limiter which concerns on this invention.

  According to the present invention, when the inner ring member and the housing member rotate relative to each other, the value of the initial rotational torque adjusted by the shield member shifting or rotating due to the frictional force or vibration during the rotation is adjusted. In order to prevent this from changing, a rotation inhibiting member that inhibits the shield member from shifting or rotating is provided. In addition, this invention is not limited to embodiment shown below. In the present specification and drawings, components having the same reference numerals indicate members having the same name.

[Embodiment 1]
The torque limiter according to the first embodiment of the present invention will be described with reference to FIGS. First, the outline of the torque limiter will be described. The torque limiter includes a housing member 1, an inner ring member 2, a first friction member 3, a second friction member 4, an elastic member 5, a shield member 6, and a rotation suppression member 7.

  In FIG. 1, the housing member 1 serves as an outer ring member and has a function of adjusting the magnitude of the rotational torque. Basically, the cylindrical portion 1A and one end of the cylindrical portion 1A that are open are provided. A threaded portion 1B formed on the inner surface on the side, a side wall portion 1C formed on the other end side, and a mounting portion 1D protruding from the side wall portion 1C. As will be described in detail later, the threaded portion 1B is for adjusting the magnitude of the rotational torque generated by the torque generating portion by screwing the shield member 6 into the threaded portion 1B.

  The side wall portion 1 </ b> C has a circular central hole 1 </ b> C <b> 1 that is slightly larger than the outer diameter of one end side of the inner ring member 2, and rotatably supports (axially supports) one end side of the inner ring member 2. A pair of mounting portions 1D are formed on the side surface of the side wall portion 1C with the central hole 1C1 interposed therebetween, and the housing member 1 is attached to a device (not shown) by fitting the mounting portion 1D into a recess or the like of a part of the device (not shown). It is for fixing. The inner surface of the cylindrical portion 1A does not need to be a cylinder, and if the inner surface of a part thereof is thick and flat, it is convenient when other members are coupled to the inner surface of the housing member so as not to rotate. Is good. Note that the attachment portion 1D is not always necessary because the housing member 1 itself may be attached to a device (not shown).

  The inner ring member 2 includes a first cylindrical portion 2A, a second cylindrical portion 2B, a first cylindrical portion 2A, and a second cylindrical portion that are rotatably supported by the central hole 1C1 of the side wall portion 1C of the housing member 1. An annular friction portion 2C having a large outer diameter formed between the second cylindrical portion 2B and a general mounting recess 2D formed on the other end side of the second cylindrical portion 2B. The friction portion 2C has annular side surfaces 2C1 and 2C2 that face each other. A frictional force acts between the annular side surfaces 2C1 and 2C2 and the first friction member 3 and the second friction member 4 to generate rotational torque. Therefore, the friction part 2C functions as a first torque generating member, and the first friction member 3 and the second friction member 4 function as a second torque generating member. In order to stabilize the rotational torque generated by the friction between the annular side surface 2C1 and the first friction member 4, an annular projection 2C11 is formed on the annular side surface 2C1. Of course, an annular protrusion similar to the protrusion 2C11 may be formed on the annular side surface 2C2. Alternatively, the protrusion 2C11 is not necessarily formed. As shown in FIGS. 1 and 2, a line extending in the longitudinal direction of the center of the inner ring member 2 is represented by an axis XY.

  The first friction member 3 and the second friction member 4 have a hole with a diameter that allows the inner ring member 2 to pass through without preferably contacting, and have a coupling portion (not shown) coupled to the housing member 1. . As an example, a part of the outer surface of the first friction member 3 and the second friction member 4 is cut and flattened, so that a so-called D-cut coupling portion (D cut portion) is formed. And the coupling | bond part is couple | bonded with the flat part in the inner surface of the housing member 1 mentioned above. Such a mechanical coupling structure is common and will not be described in detail. Therefore, the first friction member 3 and the second friction member 4 cannot rotate with respect to the housing member 1 but can move in the housing member 1 in the direction of the axis XY. Thus, although the first friction member 3 and the second friction member 4 cannot rotate with respect to the housing member 1, the mutual relationship that allows the inside of the housing member 1 to move in the direction of the axis XY is shown in FIG. Then, it is said that the first friction member 3 and the second friction member 4 are coupled to the housing member 1.

  In the first embodiment, the first friction member 3 is pressed against the inner wall of the side wall 1 </ b> C of the housing member 1 by the elastic force of the elastic member 5 described later, but depending on the thickness of the first friction member 3, The one friction member 3 does not necessarily have to be pressed against the inner wall of the side wall portion 1 </ b> C, and needs to be coupled to the cylindrical portion 1 </ b> A of the housing member 1 so as not to rotate with respect to the housing member 1. Therefore, the housing member 1 also serves as a stopper in which the first friction member 3 does not move in the Y direction from a certain position on the axis XY.

  Therefore, even if the friction part 2C rotates together with the rotation of the inner ring member 2, the first friction member 3 and the second friction member 4 do not rotate due to the frictional force generated between the friction part 2C. The friction part 2C as the first torque generating member and the first and second friction members 3 and 4 as the second torque generating member cooperate to form a torque generating part. In the torque limiter of the first embodiment, the rotational torque generated between the first friction member 3 and the annular side surface 2C1 of the friction portion 2C, the annular side surface 2C2 of the second friction member 4 and the friction portion 2C, and Rotational torque Ta combined with the rotational torque generated during Note that the coupling structure between the housing member 1 and the first friction member 3 and the second friction member 4 may not be the above-described structure, and may be a coupling structure with irregularities of an arbitrary shape. Moreover, the other well-known structure which can adjust rotational torque may be sufficient.

  The elastic member 5 has elastic force, and is between the first friction member 3 and the annular side surface 2C1 of the friction portion 2C, and between the second friction member 4 and the annular side surface 2C2 of the friction portion 2C. It is for giving a pressing force. The elastic member 5 is a plate spring such as a wave spring or a disc spring having a general structure, or an elastic body made of a coil spring or synthetic rubber, a non-contact type spring having the same polarity and having permanent magnets facing each other, and the like. Various things can be used. The elastic member 5 preferably has an inner diameter that does not contact the inner ring member 2. Since the elastic member 5 is sandwiched between the second friction member 4 coupled to the housing member 1 and a rotation restraining member 7 which will be described later, the elastic member 5 rotates in the rotational direction even when the inner ring member 2 rotates. The power of is not applied. If necessary, an annular plate such as a washer may be interposed between the elastic member 5 and the rotation suppressing member 7.

  The shield member 6 has an annular shape having a function as a side plate (lid) that rotatably supports the other end side of the inner ring member 2 and a function as a torque adjusting member that adjusts a pressing force that pressurizes the elastic member 5. Is. Both the housing member 1 and the shield member 6 constitute a housing. A threaded portion 6B that is screwed into (threaded into) the threaded portion 1B of the housing member 1 is formed on the outer periphery of the annular plate portion 6A of the shield member 6. Furthermore, an uneven portion 6C having unevenness is formed on the inner surface of the annular plate portion 6A of the shield member 6. When the threaded portion 6B of the shield member 6 is screwed into the threaded portion 1B of the housing member 1, the shield member 6 moves relative to the housing member 1 in the right direction of FIG. 1, that is, inward of the torque limiter. The pressing force applied to the member 5 is increased. When the shield member 6 is turned in the reverse direction, the shield member 6 moves to the left side in FIG. 1, that is, toward the outside of the torque limiter with respect to the housing member 1, and the pressing force applied to the elastic member 5 is reduced.

  Since the shield member 6 functions as a side plate (lid) that supports the other end side of the inner ring member 2, naturally, when the inner ring member 2 rotates, a rotational force is applied to the shield member 6. In particular, when the rotation of the inner ring member 2 starts or ends, a large rotational force may be applied due to vibration, and the rotational force is constantly applied to the shield member 6 during operation. If a special external force for stopping the rotation does not work, the shield member 6 may move in an inner or outer direction of the torque limiter around a certain angle due to the rotational force of the inner ring member 2. That is, the frictional force (or contact resistance) generated between the inner ring member 2 and the shield member 6 when the inner ring member 2 rotates is the frictional force between the threaded portion 1B of the housing member 1 and the screw portion 6B of the shield member 6 ( Or the contact resistance), the shield member 6 rotates and moves due to the rotational force of the inner ring member 2 and the vibration generated at that time. Therefore, when the torque limiter is operated by being incorporated in a device or the like, the rotational torque may gradually deviate from the initially set value, which is different from the desired rotational torque.

  It is the rotation suppression member 7 that solves this problem. The rotation suppression member 7 has an annular portion 7A, and the annular portion 7A has an uneven portion 7B on the surface in contact with the shield member 6. Moreover, the rotation suppression member 7 has the coupling convex part 7C in an outer peripheral surface. The coupling convex portion 7C is coupled to three fan-shaped coupling concave portions 1E formed on the open end side of the housing member 1 as shown in FIG. Therefore, the rotation suppression member 7 does not rotate with respect to the housing member 1. The coupling recesses 1E are formed at three equal intervals in the inner direction (the rear surface direction of the paper in FIG. 3), and the threaded portion 1B is cut at three locations by the coupling recesses 1E. There is no influence on screwing the screw portion 6B. Since the concavo-convex portion 7B of the rotation suppression member 7 and the concavo-convex portion 6C of the shield member 6 of the first embodiment increase the contact resistance with each other and increase the frictional force, these concavo-convex portions have irregular irregularities. It may also be formed.

  Friction force (contact resistance) generated between the uneven portion 7B of the rotation suppression member 7 and the uneven portion 6C of the shield member 6, and friction generated between the threaded portion 1B of the housing member 1 and the screw portion 6B of the shield member 6 The frictional force (contact resistance) that is the sum of the force (contact resistance) is the maximum frictional force generated between the shield member 6 and the inner ring member 2 during relative rotation of the inner ring member 2 and the housing member 1 ( It must be larger than the contact resistance. Considering the magnitude of the elastic force of the elastic member 5, a frictional force (contact resistance) that satisfies the above condition is generated between the uneven portion 6 </ b> C of the shield member 6 and the uneven portion 7 </ b> B of the rotation suppression member 7. As described above, the uneven portion 6C and the uneven portion 7B are determined. Therefore, the shield member 6 does not rotate by the friction force acting between the inner ring member 2 and the shield member 6 due to the rotation of the inner ring member 2, and does not move in the direction of the axis XY. However, when adjusting the rotational torque by screwing the shield member 6 into the housing member 1, the shield member 6 must naturally rotate by the rotational force at the time of adjusting the rotational torque by an operator or the like. Therefore, slip must occur between the uneven portion 7B of the rotation suppression member 7 and the uneven portion 6C of the shield member 6 with a rotational force of a certain magnitude or more.

  The torque limiter shown in FIG. 2 is obtained by incorporating the inner ring member 2, the first and second friction members 3, 4, the elastic member 5, the shield member 6, and the rotation suppression member 7 into the housing member 1. Finally, the shield member 6 is screwed into the housing member 1 using an adjustment jig (not shown), and the adjustment of the shield member 6 is stopped when the rotational torque value of the torque limiter reaches a set value. In this torque limiter, a large torque adjustment force is required as compared with the case where the rotation suppression member 7 is not provided. However, when the shield member 6 is screwed, the rotation suppression member 7 that does not rotate relative to the inner ring member 2 is elastic. It moves in the internal direction of the torque limiter against the elastic force of the member 5.

  Accordingly, the elastic member 5 contracts, and between the first friction member 3 and the annular side surface 2C1 of the friction portion 2C of the inner ring member 2, the annular side surface 2C2 of the friction portion 2C and the second friction member 4 The pressing force applied between the first friction member 3 and the annular side surface 2C1 of the friction portion 2C and the annular side surface 2C2 of the friction portion 2C and the second friction member 4 are increased. Rotational torque generated between the two increases. Conversely, when the shield member 6 is turned and loosened, the rotational torque generated between them is reduced. After the adjustment of the rotational torque, the uneven portion 7B of the rotation restraining member 7 is pressed against the uneven portion 6C of the shield member 6 by the elastic force of the elastic member 5, and a large frictional force acts between them. Even if it rotates in any direction, the shield member 6 does not move in any direction due to the influence of the frictional force between the inner ring member 2 and the shield member 6 generated during the rotation. Therefore, the adjusted initial rotational torque value can be maintained over a long period of time.

  The friction portion 2C of the inner ring member 2 and the first and second friction members 3 and 4 are preferably made of a metal material in terms of wear resistance, but may be a plastic material or the like, and the material is particularly limited. There is no need. Also, there are a plurality of friction portions 2C of the inner ring member 2, and friction members corresponding to the first and second friction members 3 and 4 are sandwiched therebetween, and the friction portions and the friction members are alternately positioned. Multiple frictional force generating structures may be used. In this case, the plurality of friction portions corresponding to the plurality of friction portions 2C rotate together with the inner ring member 2, that is, coupled to the inner ring member 2 in the rotational direction, but in the axis XY direction. It has a movable structure. In the present invention, the friction portions 2C or the plurality of friction portions corresponding to the plurality of friction portions 2C rotate together with the inner ring member 2, but the mutual relationship of moving in the axis X-Y direction is expressed by the friction portion 2C or the plurality of friction portions. It is said that a plurality of friction portions corresponding to the friction portion 2 </ b> C are coupled to the inner ring member 2.

  On the other hand, the friction members corresponding to the first and second friction members 3 and 4 can move in the direction of the axis XY, but cannot rotate with respect to the housing member 1. That is, since the plurality of friction portions corresponding to the plurality of friction portions 2C and the plurality of friction members corresponding to the first and second friction members 3 and 4 can also move in the axis XY direction, the plurality of friction portions The plurality of friction portions corresponding to 2C and the plurality of friction members corresponding to the second friction members 3 and 4 are pushed by the elastic force of the elastic member 5 and move in the Y direction in the axis XY direction to a predetermined position. In this position, they are pressed against each other by the elastic force of the elastic member 5, and torque is generated between them. Of course, the plurality of friction portions corresponding to the plurality of friction portions 2C are coupled to the inner ring member 2 in the rotation direction, and the plurality of friction members corresponding to the first and second friction members 3 and 4 are in the rotation direction. Is coupled to the housing member 1.

  For example, the inner ring member 2 in a range in which a plurality of friction portions corresponding to the plurality of friction portions 2C and a plurality of friction members corresponding to the first and second friction members 3 and 4 move in at least the axis X-Y direction, It has a polygonal structure. The plurality of friction portions corresponding to the plurality of friction portions 2C has a similar polygonal hole in which the inner ring member 2 is slightly larger than the polygonal structure, and the inner ring member 2 is inserted through the hole. The friction part 2C can move in the direction of the axis XY, but rotates together with the inner ring member 2. Further, as described above, the plurality of friction members corresponding to the first and second friction members 3 and 4 are D-cut at the outer peripheral edge, and the D-cut portion is engaged with the housing member 1. The plurality of friction members can move in the direction of the axis XY, but do not rotate. Since it is such a structure, as described above, the plurality of friction portions corresponding to the plurality of friction portions 2C and the plurality of friction members corresponding to the second friction members 3 and 4 of the elastic member 5 at the stop position. They are pressed against each other by elastic force. Therefore, the pressing force of the elastic member 5 is substantially uniform between the plurality of friction portions corresponding to the plurality of friction portions 2C and the plurality of friction members corresponding to the plurality of first and second friction members 3 and 4. And a large rotational torque that is the sum of the rotational torques generated between them can be obtained.

[Embodiment 2]
Next, a torque limiter according to a second embodiment of the present invention will be described with reference to FIGS. The torque limiter according to the second embodiment is different from the torque limiter according to the first embodiment described above mainly in the shield member 6 and the rotation restraining member 7, particularly the uneven portion 6 </ b> C and the uneven portion 7 </ b> B. The explanation will be made in relation to different parts. 4A and 4B are diagrams for explaining the uneven portion 6C of the shield member 6. FIG. 4A shows a side surface of the shield member 6, and FIG. 4B shows the shield member 6 on the right side of FIG. That is, the figure seen from the uneven | corrugated | grooved part 6C side is shown. FIG. 5 is a view for explaining the uneven portion 7B of the rotation suppression member 7, FIG. 5 (A) shows a side surface of the rotation suppression member 7, and FIG. 5 (B) is the left side of FIG. The figure seen from the uneven | corrugated | grooved part 7B side of the rotation suppression member 7 is shown. FIG. 6 shows a view before the rotation restraining member 7 is attached to the housing member 1 and closed by the shield member 6.

  As shown in FIG. 4 (B), the shield member 6 is interposed between an inner diameter surface 6E that forms a circular hole 6D that rotatably supports the inner ring member 2 and an outer diameter surface 6F that is smaller than the outer diameter of the threaded portion 6B. In addition, there is a concavo-convex portion 6C composed of concavo-convex portions having a width W1 in the rotation direction. Here, it is the triangular unevenness | corrugation which continues 3 each in a rotation direction, for example, a thick line shall show a trough and a thin line shall show the top. Twelve irregularities are formed at regular intervals of three. The unevenness may be a mountain of curves such as a kamaboko shape or a hemispherical shape instead of a triangular shape. Further, the number of irregularities may be any number as long as a necessary frictional force can be obtained between the irregularities 6C and the irregularities 7B.

  As shown in FIG. 5 (B), the rotation restraining member 7 has a diameter that does not contact the inner ring member 2, that is, an inner diameter surface 7E that forms a central hole 7D having a diameter larger than the circular hole 6D of the shield member 6, and an outer diameter. Between the surface 7F, there is a concavo-convex portion 7B made of concavo-convex portions having a constant width W2 with respect to the rotation direction. The width W2 of each concavo-convex portion of the concavo-convex portion 7B is substantially equal to the width W1 of each concavo-convex portion 6C of the shield member 6, and the concavo-convex portion 7B is a triangular concavo-convex continuous in the rotation direction. When the uneven portion 6C of the shield member 6 has a curved uneven shape such as a semi-cylindrical shape or a hemispherical shape, it becomes a wavy uneven shape having a shape opposite to the uneven shape. The frictional force between the shield member 6 and the rotation suppression member 7 is determined by the contact resistance that depends on the number and shape of the uneven portions 6C and the uneven portions 7B, the pressing force of the elastic member 5, and the like.

  Three fan-shaped coupling convex portions 7C protrude outward from the outer diameter surface 7F of the rotation restraining member 7 at substantially equal intervals, and are coupled to the three coupling concave portions 1E of the housing member 1 shown in FIG. The FIG. 6 shows a state where the rotation inhibiting member 7 is mounted on the housing member 1. The three coupling recesses 1E extend along the axis XY inward to a predetermined position. If the three coupling recesses 1E extend to the vicinity of the side wall portion 1C and the first and second friction members 3 and 4 have fan-shaped coupling portions similar to the coupling convex portions 7C, the rotation restraining member 7 In addition to the coupling convex portion 7C, the coupling portions of the first and second friction members 3 and 4 can be coupled to the coupling concave portion 1E.

  As described above, when the shield member 6 is screwed into the housing member 1 in a state where the coupling convex portion 7C of the rotation restraining member 7 is coupled to the coupling concave portion 1E of the housing member 1, the concave and convex portion 6C of the shield member 6 is The concave and convex portions 6C and the concave and convex portions 6C and the concave and convex portions 6C and the concave and convex portions 6C and the concave and convex portions 6C and the concave and convex portions 6C and the concave and convex portions 6C The portions 7B are shifted from each other one by one. In the second embodiment, since there are 20 uneven portions 7B, one rotation of the shield member 6 can be equally divided into 20 parts, that is, when expressed in terms of angles, it can be evenly adjusted by approximately 18 degrees. The rotation torque Ta can be adjusted not only easily but also accurately. In addition, when the uneven | corrugated | grooved part 6C of the shield member 6 is continuously formed over 1 round, the number of the unevenness | corrugations of the uneven | corrugated | grooved part 7B of the rotation suppression member 7 is required between the uneven | corrugated | grooved part 6C and the uneven | corrugated | grooved part 7B. As long as the frictional force is obtained, the rotation suppression member 7 can suppress the rotation of the shield member 6, so any number may be sufficient.

[Embodiment 3]
Next, a torque limiter according to a third embodiment of the present invention will be described with reference to FIG. Unlike the torque limiters of the first and second embodiments, this torque limiter does not use a rotation suppression member 7 that is separate from the shield member 6, and is a rotation suppression member 6 </ b> G that is formed or fixed integrally with the shield member 6. Is provided. Here, the rotation restraining portion formed or fixed integrally with the shield member 6 is also referred to as a rotation restraining member 6G. The rotation restraining member 6G is in contact with a part 1F on the inner surface of the housing member 1 to increase the contact resistance therebetween. 7A shows a front view in which only the shield member 6 is combined with the housing member 1, FIG. 7B shows a cross section thereof, and FIG. 7C shows FIG. 7B in FIG. A cross section is shown. Note that 6H is an adjustment recess formed on the outer surface of the shield member 6, and this adjustment recess 6H is used when adjusting the torque.

  The rotation suppression member 6G is formed integrally with the shield member 6, or is fixed to the shield member 6 by spot welding or the like. A plurality of projections and depressions are formed on the rotation restraining member 6G of the shield member 6, and the rotation restraining member 6G is lightly press-fitted into a part 1F of the inner surface of the housing member 1. That is, since the shield member 6 is press-fitted so as to rotate with a force greater than a certain amount of rotational force, the shield member 6 can be screwed into the housing member 1 without any trouble during torque adjustment, or turned in the opposite direction. Can be.

  These irregularities of the rotation inhibiting member 6G may be regularly formed, but a large number of small or fine irregularities may be irregularly formed. In addition, irregularities may be formed on a portion 1 </ b> F of the inner surface of the housing member 1. Alternatively, a large number of fine irregularities may be formed on both the rotation suppression member 6G and a part 1F of the inner surface of the housing member 1. In other words, the contact surface between the rotation restraining member 6G and the portion 1F of the inner surface of the housing member 1 on the shield member 6 is not smooth and may be a rough surface that increases the contact resistance. Moreover, a thin elastic body having elasticity such as rubber that increases the contact resistance may be wound around the rotation suppression member 6G.

  In FIG. 7B, the threaded portion 1B of the housing member 1 corresponding to the threaded portion 6B of the shield member 6 has a larger pitch of the threaded portion 1B than that of the first and second embodiments. The spiral slope is gentle. In this embodiment, the threaded portion 1B is a spiral of approximately 360 degrees having such a gentle shape. The elastic member is adjusted by moving the shield member 6 forward or backward by adjusting the shield member 6 within one rotation. 5 shows an example in which the pressing force applied to the first and second torque generating members is adjusted.

[Embodiment 4]
Next, a torque limiter according to a fourth embodiment of the present invention will be described with reference to FIGS. This torque limiter is different from the torque limiter of the first or second embodiment in that the elastic member 5 is composed of a pair of magnets facing each other with the same polarity. The elastic member 5 includes two disk-shaped magnets 5A and 5B. Each of the disk-shaped magnets 5A and 5B has a magnetic pole structure in which if one surface side is an N pole, the other surface side is an S pole. The surface sides of the disk-shaped magnets 5A and 5B facing each other have the same polarity, for example, N poles, and generate repulsive forces. Although not shown, the disk-shaped magnets 5A and 5B have a central hole through which the inner ring member 2 is inserted without contacting.

  The inner ring member 2 is combined with the first friction member 3, the second friction member 4, and the disk-shaped magnets 5 </ b> A and 5 </ b> B that are elastic members 5 and assembled into the housing member 1. Next, the rotation suppression member 7 is assembled as described above, and the shield member 6 is screwed into the housing member 1. As described above, the disk-like magnets 5A and 5B are incorporated with the same polarity on the face sides facing each other, and are naturally separated from each other at an initial interval by their repulsive force. When the shield member 6 is screwed into the housing member 1 in order to adjust the rotational torque Ta generated between the friction portion 2C of the inner ring member 2 and the first friction member 3 and the second friction member 4 on both sides thereof. Since the rotation suppression member 7 moves in the direction of the axis XY in the inner direction, the disk-shaped magnet 5B moves in the direction of the disk-shaped magnet 5A, and the distance between the disk-shaped magnets 5A and 5B decreases. The repulsive force acting between the disk-shaped magnets 5A and 5B increases.

  Along with this, the force with which the disc-shaped magnet 5A pushes the second friction member 4 increases, and the friction portion 2C of the inner ring member 2 and the first friction member 3 and the second friction member 4 on both sides thereof are interposed. Since this force increases, the rotational torque Ta also increases. When the shield member 6 is rotated in the direction opposite to the direction in which the shield member 6 is screwed into the housing member 1, the space between the disk-shaped magnets 5A and 5B expands, so that the rotation suppression member 7 and the disk-shaped magnet 5B move outward. . Accordingly, the force applied between the friction portion 2C of the inner ring member 2 and the first friction member 3 and the second friction member 4 on both sides thereof is reduced, and the rotational torque Ta is reduced.

  As described above, the first friction member 3, the second friction member 4, and the rotation suppression member 7 are coupled to the housing member 1 and do not rotate, so that they are in contact with the second friction member 4 and the rotation suppression member 7. Since the disk-shaped magnets 5A and 5B are not subjected to a force in the rotational direction and only a force in the direction of the axis XY is applied, it is particularly necessary to couple the disk-shaped magnets 5A and 5B to the housing member 1. There is no. However, for example, when the disk-shaped magnets 5A and 5B have a magnetic pole structure in which one semicircular part is an N pole and the other semicircular part is an S pole, they attract each other with different polarities. In order to prevent 5A and 5B from rotating, the disc-shaped magnets 5A and 5B must be coupled to the housing member 1. This coupling can be performed with a general structure such as D-cut as described above.

[Embodiment 5]
Next, a torque limiter according to a fifth embodiment of the present invention will be described with reference to FIGS. This torque limiter has a torque generation mechanism that generates rotational torque that is not affected by torque adjustment by the shield member 6. The first cylindrical portion 2A of the inner ring member 2 is longer than the first cylindrical portion 2A of the inner ring member 2 in the first to fourth embodiments, and the coil spring 8 is wound around the first cylindrical portion 2A. . The coil spring 8 includes a hook 8A on one end side. The coil spring 8 has a similar hook on the other end side, but the hook is behind the coil spring 8 and is not shown.

  The housing member 1 includes a hook coupling portion 1G that couples the hook 8A of the coil spring 8, and also has a hook coupling portion (not shown) that couples the hook (not shown). The hook coupling portion 1G and the hook coupling portion (not shown) are grooves extending inward from the open end side of the housing member 1. Further, the housing member 1 has a first step portion 1H that holds down the first friction member 3, and the second step portion 1J that holds down the end portion of the first cylindrical portion 2A of the inner ring member 2 on the side wall portion 1C. Is provided. An annular plate 9 is provided between the elastic member 5 and the rotation restraining member 7. The first and second friction members 3 and 4, the elastic member 5, the shield member 6, the rotation suppression member 7, and the combination structure thereof may be the same as any one of the first to fourth embodiments described above, and thus the description thereof is omitted. .

  The first cylindrical portion 2A of the inner ring member 2 and the coil spring 8 constitute a widely known torque generating mechanism. Since the mechanism for generating the rotational torque of this torque generating mechanism is well known, although not described in detail, both ends of the coil spring 8 are coupled to the housing member 1 by the hook 8A and the hook (not shown). Therefore, even if the inner ring member 2 rotates in either direction, since both ends of the coil spring 8 are coupled to the housing member 1, the coil spring 8 is loosened, and the first cylindrical portion 2A of the inner ring member 2 and A constant rotational torque is generated between the coil spring 8 and the coil spring 8. In the actual manufacturing process, the rotational torque Tb in both directions between the first cylindrical portion 2A of the inner ring member 2 and the coil spring 8 in many torque limiters is precisely matched with the desired set rotational torque Ts. Extremely difficult.

  Therefore, in the fifth embodiment, the torque generation mechanism including the first cylindrical portion 2A of the inner ring member 2 and the coil spring 8 generates a rotational torque Tb that is smaller than the set rotational torque Ts within a certain range (Ts Rotational torque Ta corresponding to -Tb) is generated by a torque generating section including the friction portion 2C of the inner ring member 2 and the first and second friction members 3 and 4. Here, Ta <Tb. That is, (Ts−Tb) = Ta, and the rotational torque Tb is often different for each manufactured torque limiter. Therefore, by adjusting the value of the rotational torque Ta, torque that always satisfies the expression Ta + Tb = Ts. A limiter can be provided.

  When the shield member 6 is screwed into the housing member 1 during the adjustment of the rotational torque Ta, the first friction member 3 is pressed against the first step portion 1H of the housing member 1 and functions as a stopper. Therefore, the torque generating mechanism including the first cylindrical portion 2A of the inner ring member 2 and the coil spring 8 is not affected by the pressing force of the elastic member 5 and is not limited to the adjustment of the rotational torque Ta, and is substantially constant. The torque Tb is maintained. From this, the rotational amount Ta generated by the torque generating part composed of the friction part 2C of the inner ring member 2 and the first and second friction members 3 and 4 is adjusted by adjusting the screwing amount of the shield member 6 with respect to the housing member 1. , Ta + Tb = Ts is adjusted so as to satisfy the expression, a torque limiter that generates a rotational torque equal to the set rotational torque Ts can be obtained.

  The torque generation mechanism can employ various structures other than those described above, and can employ a known torque generation structure. For example, a contact-type torque limiter using various shapes of spring members as disclosed in the above-mentioned Patent Documents 1 to 8, or a non-contact type torque limiter using a permanent magnet may be used. In the above description, the case where the inner ring member 2 rotates has been described, but the housing member 1 may rotate.

  Next, a modified example of the friction portion 2C of the inner ring member 2 will be described. The frictional portion 2C described so far is an annular one formed integrally with the inner ring member 2, but is separate from the inner ring member 2 as shown in FIGS. 12 (A) and 12 (B). The formed annular member 2Cx may be fixed to the fixing portion 2E of the inner ring member 2. 12B, the first friction member 3 and the second friction member 4 sandwich the annular member 2Cx as in the above-described embodiments, as indicated by a broken line. Pressed from both sides. Since the contact between the annular member 2Cx and the first friction member 3 and the second friction member 4 is a circular line contact, the annular member 2Cx, the first friction member 3, and the second friction member 4 Rotational torque value generated between the two is stabilized, and the torque ripple can be reduced. In particular, when the inner ring member 2 is made of a resin material, the annular member 2Cx is formed of a metal material similar to that of the first friction member 3 and the second friction member 4, thereby greatly improving wear resistance. The life can be improved.

  In the example of FIG. 12, the inner ring member 2 has a relatively thin cylindrical shape. Therefore, the fixing portion 2E is formed in an annular shape having a relatively large diameter in consideration of mechanical reinforcement. When the member 2 is a thick cylindrical or columnar member, the annular member 2Cx may be directly fixed to the inner ring member 2 by press fitting or screwing. Further, the first friction member 3 and the second friction member 4 described above may have an annular shape having an inner diameter and an outer diameter substantially equal to the annular member 2Cx. The same applies to other embodiments.

  As described above, the present invention is suitable for a structure in which the threaded portion 1B of the housing member 1 spirals at a gentle slope (pitch) at approximately 360 degrees or several times, but is not limited thereto. Absent. With such a structure, not only the length of the torque limiter in the axis XY direction can be shortened, that is, the size can be reduced, but also the elastic member can be easily formed without rotating the shield member 6 many times. 5 can adjust the magnitude of the pressing force applied to the first and second torque generating members, and a desired torque value can be easily obtained.

  The present invention can be widely applied to a rotation mechanism in a paper feeding mechanism of a printer or a copying machine, or other OA equipment and precision equipment.

DESCRIPTION OF SYMBOLS 1 ... Housing member 1A ... Cylindrical part 1B ... Threaded part 1C ... Side wall part 1C1 ... Center hole 1D ... Mounting part 1E ... Coupling recessed part 1F ... Housing member 1 1G ... Hook coupling part 1H ... Step part 1J ... Step part 2 ... Inner ring member 2A ... First cylinder part 2B ... Second cylinder part 2C ... Friction parts 2C1, 2C2 ... annular side surface 2C11 ... annular protrusion 2D ... mounting recess 2E ... fixed part 2Cx ... annular member 3 ... first friction member 4. .... Second friction member 5 ... Elastic member 5A, 5B ... Disc-shaped magnet 6 ... Shield member 6A ... Annular plate part 6B ... Screw part 6C ... Uneven part 6D・ ・ ・ Circular hole 6E ・ ・ ・ Inner diameter surface forming circular hole 6D 6F ・ ・ ・ Outer diameter surface 6G ・ ・・ Rotation restraint member 6H: Adjustment recess 7 ... Rotation restraint member 7A ... Annular portion 7B ... Uneven portion 7C ... Coupling projection 7D ... Center hole 7E ... Center Inner diameter surface forming hole 7D 7F ... outer diameter surface 8 ... coil spring 8A ... hook of coil spring 8 9 ... annular plate Ta ... rotational torque to be adjusted Tb ... torque Rotational torque generated by the generation mechanism Ts ... Set rotational torque

Claims (6)

A housing member comprising a cylindrical portion having a threaded portion on the inner surface on one end side that is open, and a side wall portion on the other end side of the cylindrical portion;
A shield member having a thread portion screwed into the threaded portion of the housing member;
An inner ring member supported by the side wall portion of the housing member and the shield member and rotatable relative to the housing member;
A first torque generating member that rotates together with the inner ring member; a second torque generating member that is coupled to the housing member and that generates an adjustable rotational torque Ta with the first torque generating member;
An elastic member that gives the first and second torque generating members a pressing force that changes in magnitude depending on the degree of screwing of the threaded portion of the shield member into the threaded portion of the housing;
A rotation restraining member that prevents the screw portion of the shield member and the threaded portion of the housing member from rotating relative to each other due to the influence of relative rotation between the inner ring member and the housing member;
Torque limiter characterized by comprising. The torque limiter according to claim 1,
The rotation suppression member and the shield member have contact surfaces that contact each other,
The frictional force that is the sum of the frictional force acting on the contact surface and the frictional force acting between the threaded portion of the housing member and the threaded portion of the shield member is relative to the inner ring member and the housing member. A torque limiter characterized in that the torque limiter is larger than a frictional force generated between the shield portion and the inner ring member that is generated when the inner ring member rotates. The torque limiter according to claim 2,
On the contact surface between the shield member and the rotation suppression member, irregularities having a constant width in the rotation direction of the shield member are formed,
A torque limiter characterized in that the unevenness can adjust the rotation angle of the shield member stepwise according to the unevenness. The torque limiter according to claim 1,
The shield member includes the rotation suppression member integrally formed or fixed,
The inner surface of the housing member and the rotation suppression member of the shield member have contact surfaces that contact each other,
An unevenness for increasing a friction force acting on the contact surface is formed on one of the contact surface of the housing member and the contact surface of the rotation suppression member of the shield member. Torque limiter. The torque limiter according to claim 1,
The first torque generating member is composed of a friction portion formed or fixed integrally with the inner ring member,
The second torque generating member comprises a friction member coupled to the housing member;
The friction limiter and the friction member rotate relatively to generate the rotational torque Ta. The torque limiter according to any one of claims 1 to 5,
A torque generating mechanism that is positioned between the first or second torque generating member and the side wall portion of the housing member and generates a constant rotational torque between the inner ring member or the housing member;
The torque generation mechanism generates a one-way or two-way rotation torque Tb larger than the rotation torque Ta,
Torque that generates a rotational torque (Ta + Tb) having a predetermined magnitude equal to the sum of the rotational torque Ta adjusted by turning the shield member and the constant rotational torque Tb generated by the torque generating mechanism. limiter.

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