JP6116608B2 - Torque limiter manufacturing method - Google Patents

Description

The present invention includes a relatively rotatable inner ring and outer ring, and a coil spring mounted between the inner ring and the outer ring. When the rotational torque for relatively rotating the inner ring and the outer ring is greater than a predetermined value, the coil spring It overcomes the frictional force to a method for manufacturing a torque limit data that the outer and inner rings are relatively rotated.

  In printers and copiers, a paper feeding device is used to feed paper one by one from a group of sheets stacked in the vertical direction. In such a paper feeding device, the paper is taken out from the paper group in a multi-layer state in which a plurality of papers are adsorbed up and down by a minute mutual adsorption force such as static electricity, and the paper is left in the multi-layer state in a printer or a copier. In order to avoid this, the sheet feeding device is usually equipped with a torque limiter.

  FIG. 7 shows an example of a paper feeder using a torque limiter disclosed in Patent Document 1. The paper feeding device S is connected to an appropriate drive source such as a motor and rotates, and the drive roller KR rotates in parallel with the rotation axis of the drive roller KR and following the rotation of the drive roller KR. It has a driven roller JR and a paper tray PT that supports the paper group. The surfaces of the driving roller KR and the driven roller JR are both covered with a resin material having a relatively high coefficient of friction and elasticity, and the driving roller KR and the driven roller JR are made by appropriate biasing means such as a spring. It is in close contact. A torque limiter TL is incorporated in the driven roller JR.

When only one sheet is fed from the stacked sheet group to the sheet feeding device, as shown in FIG. 7A, the surface of the sheet positioned on the upper surface of the stacked sheet group and the driving roller KR. One sheet P sent out by the frictional force is fed to the sheet feeding device S and is brought into close contact with the driving roller KR and the driven roller JR. Then, the frictional force between the driving roller KR that rotates counterclockwise and the upper surface of the paper P causes the paper P to be fed in the rotational direction of the driving roller KR, and the driven roller JR transmits the frictional force via the paper P. As a result, a rotational torque larger than a predetermined value is applied in the clockwise direction and the driven rotation occurs.
On the other hand, when the sheets are fed from the sheet group to the sheet feeding device in the state where the sheets are stacked in the vertical direction, as shown in FIG. 7B, the stacked sheets P1 and P2 remain in the stacked state and the driving roller KR. The driving roller KR is in close contact with the upper surface of the upper paper P1, and the driven roller JR is in close contact with the lower surface of the lower paper P2. The upper sheet P1 is about to be sent out in the rotation direction of the driving roller KR by the frictional force between the driving roller KR that rotates counterclockwise and the upper sheet P1. However, the upper sheet P1 and the lower sheet P2 are only adsorbed by a minute mutual adsorption force that is smaller than the frictional force. When the frictional force is applied to the upper sheet P1, the upper sheet P1 is adsorbed. P1 is peeled off from the lower sheet P2, and slippage occurs between the upper sheet P1 and the lower sheet P2. Therefore, a relatively small rotational torque of a predetermined value or less is applied to the driven roller JR via the lower sheet P2. In such a case, the rotation of the driven roller JR is locked by the torque limiter TL. When the driven roller JR is locked, the printer or copier notifies the user that the paper is in a multi-layer state based on this, and prompts the user to remove the multi-layer paper.

  The torque limiter is not limited to the sheet feeding device, and is also used as a component for protecting the motor by cutting off the load when an overload is applied to the motor or the like of the drive source. As a torque limiter, for example, a friction type described in Patent Document 2 is known, and this will be described with reference to FIG. The friction type torque limiter is inserted into the shaft-shaped inner ring N, a coil spring B which is attached to the outer peripheral surface of the inner ring N and applies a frictional force, and the inner ring N to which the coil spring B is mounted. And a cylindrical outer ring G. The inner ring N has a cylindrical shape, and its outer diameter is larger than the diameter of the coil spring B in a free state (a state where no force is applied to the spring). An engaging portion K1 extending in the normal direction is formed at the tip of the coil spring B in the central axis direction, and an engaged portion K2 that engages with the engaging portion K1 is formed on the inner peripheral surface of the outer ring G. Is formed.

  Such assembling of the torque limiter TL is usually performed as follows. First, a paste-like lubricant is applied to the coil spring B. Next, with the coil spring B fixed, the inner ring N is inserted into the coil spring B while increasing the inner diameter of the coil spring B using an assembling apparatus having a dedicated taper jig, and the coil spring B is inserted into the inner ring. N is located at a predetermined position. After the coil spring B is mounted in contact with the outer peripheral surface of the inner ring N in this way, it is removed from the assembling apparatus. Then, the inner ring N to which the coil spring B is mounted is inserted into the outer ring G by engaging the engaging portion K1 of the coil spring B with the engaged portion K2.

JP 2008-274799 A JP 2006-307934 A

As described above, in the friction type torque limiter, the inner ring N has a cylindrical shape, and its outer diameter is larger than the diameter of the coil spring B in the free state.
That is, when the coil spring B is attached to the inner ring N, first, while the coil spring B is fixed, an assembling apparatus having a dedicated taper jig is used to increase the inner diameter of the coil spring B. The coil spring B is attached to the outer peripheral surface of the inner ring N. That is, for mounting the coil spring B, it is necessary to use an assembling apparatus equipped with a special jig, and the jig is installed in the assembling apparatus, or the coil spring B and the inner ring N are set in the assembling apparatus. It takes time and effort. This operation is usually performed manually by an operator one by one, resulting in an increase in manufacturing cost and a decrease in manufacturing efficiency due to the complexity of the manufacturing process.
An object of the present invention is to solve the problem of such an assembly method in a friction type torque limiter having a coil spring.

In view of the above problems, the first invention of the present patent application is a coil spring placed at the top of the coil spring insertion jig small diameter portion of the inner ring is provided with insertable inner ring insertion hole, the inner ring from above the coil spring and inner ring After being inserted into the insertion hole, the inner ring is pressed from above, and the coil spring is attached to the large diameter part of the inner ring while gradually increasing the diameter of the coil spring by the tapered part of the inner ring . That is, the first invention of the present patent application is
“A shaft-shaped inner ring, a coil spring mounted in contact with the outer peripheral surface of the inner ring, and a cylindrical outer ring into which the inner ring mounted with the coil spring is inserted,
The inner ring and the outer ring have a common center axis, and the coil spring is engaged with the outer ring so as not to be relatively rotatable,
When a rotational torque around the central axis that relatively rotates the inner ring and the outer ring in a direction that relaxes the tightening force of the coil spring is added, when the rotational torque is greater than a predetermined value, and the inner ring and the outer ring is relatively rotated by overcoming the frictional force between the coil spring and the inner ring,
The inner ring has a large-diameter portion to which the coil spring is attached, a small-diameter portion formed on the tip side of the large-diameter portion, and a tapered portion formed between the large-diameter portion and the small-diameter portion. And
The diameter of the large-diameter portion is larger than the inner diameter of the coil spring in a free state, the diameter of the small-diameter portion is smaller than the inner diameter of the coil spring in a free state, and the tapered portion has a minimum diameter. Is a torque limiter in which the maximum diameter is set equal to the diameter of the large-diameter portion, which is smaller than the inner diameter of the coil spring in a free state ,
After the coil spring is installed on the upper part of a coil spring insertion jig having an inner ring insertion hole into which the small diameter portion of the inner ring can be inserted, the inner ring is inserted into the inner ring insertion hole from above the coil spring, and then the inner ring The coil spring is attached to the large diameter portion of the inner ring while gradually increasing the diameter of the coil spring by the tapered portion of the inner ring.
It is the mounting method characterized by this.
In the second invention of the present application, the outer ring is inserted into the outer ring insertion hole of the inner ring insertion jig provided with the outer ring insertion hole into which the outer ring can be inserted, the inner ring with the coil spring is inserted into the outer ring, The stepped groove portion of the inner ring is fitted into the inwardly protruding portion of the outer ring. That is, the second invention of the present application is
“A shaft-shaped inner ring, a coil spring mounted in contact with the outer peripheral surface of the inner ring, and a cylindrical outer ring into which the inner ring mounted with the coil spring is inserted,
The inner ring and the outer ring have a common center axis, and the coil spring is engaged with the outer ring so as not to be relatively rotatable,
When a rotational torque around the central axis that relatively rotates the inner ring and the outer ring in a direction that relaxes the tightening force of the coil spring is added, when the rotational torque is greater than a predetermined value, Overcoming the frictional force between the coil spring and the inner ring, the outer ring and the inner ring rotate relatively,
The inner ring has a large-diameter portion to which the coil spring is attached, a small-diameter portion formed on the tip side of the large-diameter portion, and a tapered portion formed between the large-diameter portion and the small-diameter portion. And
The diameter of the large-diameter portion is larger than the inner diameter of the coil spring in a free state, the diameter of the small-diameter portion is smaller than the inner diameter of the coil spring in a free state, and the tapered portion has a minimum diameter. Is smaller than the inner diameter of the coil spring in the free state, the maximum diameter is set equal to the diameter of the large diameter portion,
The coil spring is mounted in a torque limiter in which a stepped groove is formed at the tip of the small-diameter portion of the inner ring, and an inward projection is formed in the outer ring that fits into the stepped groove. An assembly method of the inner ring and the outer ring,
After inserting the outer ring into the outer ring insertion hole of an inner ring insertion jig having an outer ring insertion hole into which the outer ring can be inserted, and inserting the inner ring on which the coil spring is mounted into the outer ring, the inner ring is moved to the center. Press in the axial direction and fit the stepped groove of the inner ring into the inward projection of the outer ring "
The assembly method is characterized by this.

The torque limiter is produced by the first invention and the second invention of the present gun together a shaft-like inner ring, and a coil spring which is mounted in contact with the outer peripheral surface of the inner ring, the loaded inner ring of the coil spring is inserted And a cylindrical outer ring. The inner ring and the outer ring have a common central axis, the coil spring is engaged with the outer ring so as not to rotate relative to the outer ring, and when the rotational torque between the inner ring and the outer ring is greater than a predetermined value, the coil spring and the inner ring Overcoming the frictional force between the outer ring and the inner ring relatively rotate. These are the same as the conventional torque limiter, but in the present invention, the inner ring has a large-diameter portion to which the coil spring is attached, a small-diameter portion formed on the tip side, a large-diameter portion and a small-diameter portion. A taper portion formed in the middle, and the taper portion has a minimum diameter smaller than the inner diameter of the coil spring in a free state, and the maximum diameter is set equal to the diameter of the large diameter portion.
The torque limiter manufactured by the second invention of the present application further includes a stepped groove portion formed at the tip of the small diameter portion of the inner ring, and an inward projection portion into which the stepped groove portion is fitted is formed on the outer ring. Yes.

In the first invention of the present application, when the coil spring is mounted on the inner ring, the coil spring is fitted to the small diameter portion of the inner ring, and then the inner ring is pressed in the direction of the small diameter portion. The inner diameter of the inner ring is gradually expanded by the taper portion of the inner ring and attached to the large diameter portion of the inner ring. Therefore, when attaching the coil spring to the inner ring, the coil spring can be easily attached to the inner ring without using an assembling apparatus provided with a special jig for expanding the diameter of the coil spring. Furthermore, the attachment of the coil spring to the inner ring can be automated by a machine, not by manual work, so that the manufacturing cost can be reduced and the manufacturing efficiency can be dramatically increased.
In the second invention of the present application, when assembling the inner ring and the outer ring on which the coil spring is mounted, the outer ring is inserted into the outer ring insertion hole of the inner ring insertion jig, and the inner ring on which the coil spring is mounted is inserted into the outer ring. After that, the inner ring is pressed in the direction of the central axis, and the stepped groove portion of the inner ring is fitted into the inward projection of the outer ring, thereby assembling the inner ring and the outer ring on which the coil spring is mounted. Therefore, when assembling the inner ring and the outer ring on which the coil springs are mounted, it is possible to automate by a machine without depending on manual work, and it is possible to reduce manufacturing costs and dramatically increase manufacturing efficiency. .

It is a structural diagram showing an embodiment of a torque limiter manufactured by the present invention. It is a single figure of the inner ring | wheel of the torque limiter shown in FIG. It is a single figure of the outer ring | wheel of the torque limiter shown in FIG. It is a single figure of the coil spring of the torque limiter shown in FIG. It is a figure explaining the process of attaching a coil spring to an inner ring in the process of assembling the torque limiter shown in FIG. It is a figure explaining the process of assembling the inner ring | wheel and the outer ring | wheel with which the coil spring was mounted | worn in the process of assembling the torque limiter shown in FIG. It is a figure explaining the action | operation of the paper feeder provided with the torque limiter. It is a figure which shows an example of the conventional friction type torque limiter.

Hereinafter, a method for manufacturing a torque limiter of the present invention will be described with reference to the drawings. FIG. 1 shows an overall structure of an embodiment of a torque limiter manufactured according to the present invention, and parts diagrams thereof are shown in FIGS. 5 and 6 are diagrams for explaining a process of assembling the torque limiter of the present invention.

  As shown in FIG. 1, the torque limiter of this embodiment indicated by reference numeral 1 includes an inner ring 2, an outer ring 3, and a coil spring 4. The inner ring 2 is inserted into the outer ring 3 with the coil spring 4 mounted on the outer periphery, and the inner ring 2 and the outer ring 3 have a common center axis o.

  Referring to FIG. 2 together with FIG. 1, the inner ring 2 has a shaft shape centered on the central axis o, a large diameter portion 21 to which the coil spring 4 is attached, and a distal end side of the large diameter portion 21 And a tapered portion 23 formed between the large-diameter portion 21 and the small-diameter portion 22. In this embodiment, the inner ring 2 is formed by forging.

The large diameter portion 21 has a cylindrical shape, and the small diameter portion 22 also has a cylindrical shape as a whole. The tapered portion 23 has a truncated cone shape whose cross-sectional diameter gradually decreases from the rear end toward the front end, and the rear end is continuously connected to the large diameter portion 21. If desired, the upper and lower sides of the longitudinal cross-sectional shape including the central axis o may be curved instead of straight. The diameter of the large diameter portion 21 is larger than the inner diameter of the coil spring 4 in the free state, and the diameter of the small diameter portion 22 is smaller than the inner diameter of the coil spring in the free state. The tapered portion 23 has a minimum diameter smaller than the inner diameter of the coil spring 4 in the free state, and the maximum diameter is equal to the diameter of the large diameter portion 21.
In the illustrated embodiment, the diameter of the small diameter portion 22 is smaller than the minimum diameter of the tapered portion 23, and the tapered portion 23 and the small diameter portion 22 are connected via a step portion 24. A stepped groove portion 25 into which an inward projection formed on the outer ring 3 to be described later is fitted is formed at the distal end portion of the small diameter portion 22. The stepped groove portion 25 is formed on the outer peripheral surface of the small diameter portion 22 over the entire circumference. An annular collar 26 is formed at the rear end of the large-diameter portion 21, and a connecting portion 27 in which a part of the columnar shape is cut out is formed at the rear end surface.

  Referring to FIG. 3 together with FIG. 1, the outer ring 3 is a cylindrical member centered on the central axis o, and includes a rear portion 31 having a relatively large outer diameter and a front portion 32 having a relatively small outer diameter. Have In this embodiment, the outer ring 3 is formed by injection molding a thermoplastic resin such as polyacetal.

A first cavity 311 is formed inside the rear portion 31. The inner diameter of the first cavity portion 311 is large enough to accommodate the above-described annular flange portion 26 of the inner ring 2. A second cavity 312 is formed in front of the first cavity 311. The inner diameter of the second cavity portion 312 is smaller than the diameter of the first cavity portion 311, and the first cavity portion is interposed between the second cavity portion 312 and the first cavity portion 311 when viewed in the axial direction. A substantially annular shoulder surface 311a facing the 311 side is formed. On the upper side of the second cavity 312, a protrusion cavity 313 extending in the axial direction of the central axis o is attached.

  A third cavity 314 is formed inside the front part 32 of the outer ring 3, and a fourth cavity 315 is formed in front of the third cavity 314. The third cavity portion 314 and the fourth cavity portion 315 are cylindrical, and the inner diameter of the third cavity portion 314 is equal to the large diameter portion 21 of the inner ring 2, and the inner diameter of the fourth cavity portion 315 is It is set equal to the small diameter portion 22 of the inner ring 2. Therefore, the large-diameter portion 21 and the small-diameter portion 22 of the inner ring 2 can be fitted into these hollow portions without any gap. An inward projection 316 that fits into the stepped groove 25 of the inner ring 2 is formed on the inner peripheral surface at the front end of the fourth cavity 315.

  Referring to FIG. 4 together with FIG. 1, the metal coil spring 4 is spirally wound around the central axis o, and the distal end portion of the metal coil spring 4 with respect to the central axis o (that is, in the winding direction). On the other hand, an engaging portion 41 is formed which extends in a substantially vertical direction and away from the central axis o. It is preferable that a lubricant such as grease is applied to the coil spring 4 in advance.

Method for assembling bets Rukurimitta 1 described above, will be described below with reference to FIGS together with FIG.
First, the coil spring 4 is attached to the inner ring 2 using the coil spring insertion jig 5. As shown in FIG. 5, the coil spring insertion jig 5 has a large number of inner ring insertion holes 51 into which the small diameter portion 22 of the inner ring 2 can be inserted, and the inner ring insertion hole 51 has an inner diameter slightly lower than the lower part. A large coil spring installation portion 52 is formed coaxially. When attaching the coil spring 4 to the inner ring 2, first, the coil spring 4 is installed on the coil spring installation portion 52 so that the engaging portion 41 is positioned below (FIG. 5A). Although illustration is omitted, when installing the coil spring 4, another guide jig (pallet) in which a guide hole penetrating vertically is formed at a position corresponding to the inner ring insertion hole 51, and fine vibration is applied to this. It is preferable that the coil spring 4 is aligned and dropped into the coil spring installation portion 52.
A lubricant is applied to the coil spring 4 in advance, and grease diluted with a solvent is used as the lubricant for that purpose. This lubricant is in a liquid state, and a required amount of lubricant can be applied to a large number of coil springs 4 in one operation by putting the coil spring 4 into a container or the like filled with the lubricant. Therefore, compared with the conventional case where the paste-like lubricant is manually applied to the coil spring 4 one by one, the working efficiency can be greatly improved, and excessive application of the lubricant can be prevented. This contributes to a reduction in material cost.

Next, the inner ring 2 is inserted into the inner ring insertion hole 51 from above the coil spring 4 with the tip of the small diameter portion 22 facing downward. As shown in FIG. 5B, at this time, another guide jig in which a guide hole penetrating vertically is formed at a position corresponding to the inner ring insertion hole 51 to give fine vibrations to the inner ring 2. It is preferable to align them and drop them into the inner ring insertion hole 51. In a state where the inner ring 2 is inserted into the inner ring insertion hole 51 from above the coil spring 4, the coil spring 4 is loosely fitted with the inner ring 2 at the small diameter portion 22 which is smaller than the inner diameter of the coil spring 4 in the free state. It is fitted in a state with a gap.
And the inner ring | wheel 2 is pressed from upper direction with appropriate press machines, such as a press machine (FIG.5 (c)). The coil spring 4 is gradually expanded in diameter by the tapered portion 23 of the inner ring 2 by pressing the inner ring 2 from above from the state where the coil spring 4 is loosely fitted to the inner ring 2 in the small diameter portion of the inner ring 2. While moving, it moves to the large-diameter portion 21 that is larger than the inner diameter of the coil spring 4 in the free state, and comes into contact with the outer peripheral surface of the large-diameter portion 21 of the inner ring 2.

In the torque limiter 1 manufactured by the present invention, the coil spring 4 is installed above the coil spring insertion hole 51, and the inner ring 2 is inserted into the inner ring insertion hole 51 from above the coil spring 4. By pressing from above, the coil spring 4 can be mounted in contact with the outer peripheral surface of the inner ring 2. When attaching the coil spring 4 to the inner ring 2, it is not necessary to use a special jig for expanding the diameter of the coil spring 4, and the jig attaching / detaching operation which has been conventionally performed manually becomes unnecessary. Therefore, the attachment of the coil spring 4 to the outer peripheral surface of the inner ring 2 can be performed by automation by a machine so that a large number of attachments can be made simultaneously, and the production efficiency can be dramatically increased.

After the coil spring 4 is mounted on the inner ring 2 in this way, the inner ring 2 and the outer ring 3 on which the coil spring 4 is mounted are assembled using the inner ring insertion jig 6. As shown in FIG. 6, the inner ring insertion jig 6 includes a large number of outer ring insertion holes 61 into which the outer ring 3 can be inserted. When assembling the inner ring 2 and the outer ring 3 to which the coil spring 4 is attached, first, the outer ring 3 is inserted into the outer ring insertion hole 61 with the front end 32 at the leading end (FIG. 6A). Next, the inner ring 2 on which the coil spring 4 is mounted is inserted into the outer ring 3 inserted into the outer ring insertion hole 61 with the tip of the small diameter portion 22 facing downward (FIG. 6B). At this time, similarly to the case shown in FIG. 5B, the coil spring 4 is used by using another guide jig (not shown) in which a guide hole penetrating vertically is formed at a position corresponding to the outer ring insertion hole 61. Drop the inner ring 2 fitted with. When inserting the inner ring 2 to which the coil spring 4 is attached into the outer ring 3, it is necessary to align the engaging part 41 of the coil spring 4 with the protruding cavity part 313 formed in the second cavity part 312 of the outer ring 3. However, in this embodiment, after the inner ring 2 with the coil spring 4 attached is inserted into the outer ring 3, the outer ring insertion hole 61 into which the outer ring 3 is inserted is subjected to horizontal vibration by an appropriate vibrator. Thus, the relative positioning of the engaging portion 41 and the protrusion cavity portion 313 is performed.
When the insertion of the inner ring 2 fitted with the coil spring 4 into the outer ring 3 is completed, the inner ring 2 is pressed from above by an appropriate pressing machine such as a press machine (FIG. 6C). Thus, the stepped groove 25 of the inner ring 2 is fitted into the inward projection 316 of the outer ring 3 and the flange portion 26 of the inner ring 2 is engaged with the shoulder 311a of the outer ring 3 in the axial direction, so that the inner ring 2 is 3 in the axial direction. Further, the engaging portion 41 of the coil spring 4 is pushed into the protruding cavity portion 313, and the coil spring 4 is fixed to the outer ring 3.

The operation of bets Rukurimitta 1 assembled as described above, will be described with reference to FIG.
When a rotational torque larger than a predetermined value (torque in a direction to relieve the tightening force of the coil spring 4) is applied around the central axis o that relatively rotates the inner ring 2 and the outer ring 3, the coil spring 4 The friction force between the coil spring 4 and the inner ring 2 due to the tightening force is overcome, and the outer ring 3 and the inner ring 2 rotate relatively. At this time, the inner diameter of the third cavity portion 314 is set equal to the large diameter portion 21 of the inner ring 2, and the inner diameter of the fourth cavity portion 315 is set equal to the small diameter portion 22 of the inner ring 2. 3 is prevented from shaking. Further, a stepped groove 25 is formed at the tip of the small diameter portion 21 in the inner ring 2, and an inward projection 316 that fits into the stepped groove 25 is formed in the outer ring 3, thereby rotating. The outer ring 3 is prevented from moving in the axial direction of the central axis o, and the relative rotation of both is stabilized.
On the other hand, if the rotational torque for relatively rotating the inner ring 2 and the outer ring 3 is equal to or less than a predetermined value, relative rotation does not occur due to the frictional force between the inner ring 2 and the coil spring 4. Further, when the rotational torque is a torque in a direction to increase the tightening force of the coil spring 4, the frictional force is increased thereby, so that the inner ring 2 and the outer ring 3 do not rotate relatively.

As described above in detail, in the torque limiter manufactured by the present invention, the inner ring has a large-diameter portion on which a coil spring is mounted, a small-diameter portion formed on the tip side of the large-diameter portion, a large-diameter portion and a small-diameter. A tapered portion formed in the middle of the portion, and the tapered portion has a minimum diameter smaller than the inner diameter of the coil spring in a free state, and the maximum diameter is set equal to the diameter of the large diameter portion. . Therefore, the coil spring can be easily attached to the inner ring without using a jig for expanding the diameter of the coil spring. In the above embodiment, the inner ring is manufactured by forging, but it goes without saying that it can be manufactured by sintering or pressing. Further, the method of assembling a large number of torque limiters at the time of assembling the torque limiter has been described. However, it is obvious that the above-described embodiments can be appropriately changed, such as assembling one by one.

1: Torque limiter 2: Inner ring 21: Large diameter part 22: Small diameter part 23: Tapered part 24: Step part 25: Stepped groove part 3: Outer ring 314: Third cavity part (rear cavity part)
315: Fourth cavity (front cavity)
316: Inward projection 4: Coil spring 5: Coil spring insertion jig 51: Inner ring insertion hole 6: Inner ring insertion jig 61: Outer ring insertion hole

Claims (7)

A shaft-shaped inner ring, a coil spring mounted in contact with the outer peripheral surface of the inner ring, and a cylindrical outer ring into which the inner ring mounted with the coil spring is inserted,
The inner ring and the outer ring have a common center axis, and the coil spring is engaged with the outer ring so as not to be relatively rotatable,
When a rotational torque around the central axis that relatively rotates the inner ring and the outer ring in a direction that relaxes the tightening force of the coil spring is added, when the rotational torque is greater than a predetermined value, and the inner ring and the outer ring is relatively rotated by overcoming the frictional force between the coil spring and the inner ring,
The inner ring has a large-diameter portion to which the coil spring is attached, a small-diameter portion formed on the tip side of the large-diameter portion, and a tapered portion formed between the large-diameter portion and the small-diameter portion. And
The diameter of the large-diameter portion is larger than the inner diameter of the coil spring in a free state, the diameter of the small-diameter portion is smaller than the inner diameter of the coil spring in a free state, and the tapered portion has a minimum diameter. Is a torque limiter in which the maximum diameter is set equal to the diameter of the large-diameter portion, which is smaller than the inner diameter of the coil spring in a free state ,
After the coil spring is installed on the upper part of a coil spring insertion jig having an inner ring insertion hole into which the small diameter portion of the inner ring can be inserted, the inner ring is inserted into the inner ring insertion hole from above the coil spring, and then the inner ring Is attached from above, and the coil spring is attached to the large diameter portion of the inner ring while gradually increasing the diameter of the coil spring by the tapered portion of the inner ring. The mounting method according to claim 1, wherein a diameter of the small diameter portion of the inner ring is smaller than a minimum diameter of the tapered portion, and the tapered portion and the small diameter portion are connected via a step portion. The said outer ring | wheel has a back cavity part which has an internal diameter equal to the outer diameter of the large diameter part of the said inner ring | wheel, and a front cavity part which has an internal diameter equal to the outer diameter of the small diameter part of the said inner ring | wheel. How to wear . The mounting method according to claim 1, wherein grease diluted with a solvent is applied to the coil spring. 5. The step according to claim 1, wherein a stepped groove portion is formed at a tip portion of the small diameter portion of the inner ring, and an inward projection portion that fits into the stepped groove portion is formed on the outer ring. The mounting method described. An assembly method of the inner ring and the outer ring on which the coil spring is mounted by the mounting method according to any one of claims 1 to 5 ,
After inserting the outer ring into the outer ring insertion hole of an inner ring insertion jig having an outer ring insertion hole into which the outer ring can be inserted, and inserting the inner ring on which the coil spring is mounted into the outer ring, the inner ring is moved to the center. An assembly method comprising pressing in an axial direction and fitting a stepped groove portion of the inner ring into an inward protruding portion of the outer ring. A shaft-shaped inner ring, a coil spring mounted in contact with the outer peripheral surface of the inner ring, and a cylindrical outer ring into which the inner ring mounted with the coil spring is inserted,
The inner ring and the outer ring have a common center axis, and the coil spring is engaged with the outer ring so as not to be relatively rotatable,
When a rotational torque around the central axis that relatively rotates the inner ring and the outer ring in a direction that relaxes the tightening force of the coil spring is added, when the rotational torque is greater than a predetermined value, Overcoming the frictional force between the coil spring and the inner ring, the outer ring and the inner ring rotate relatively,
The inner ring has a large-diameter portion to which the coil spring is attached, a small-diameter portion formed on the tip side of the large-diameter portion, and a tapered portion formed between the large-diameter portion and the small-diameter portion. And
The diameter of the large-diameter portion is larger than the inner diameter of the coil spring in a free state, the diameter of the small-diameter portion is smaller than the inner diameter of the coil spring in a free state, and the tapered portion has a minimum diameter. Is smaller than the inner diameter of the coil spring in the free state, the maximum diameter is set equal to the diameter of the large diameter portion,
The coil spring is mounted in a torque limiter in which a stepped groove is formed at the tip of the small-diameter portion of the inner ring, and an inward projection is formed in the outer ring that fits into the stepped groove. An assembly method of the inner ring and the outer ring,
After inserting the outer ring into the outer ring insertion hole of an inner ring insertion jig having an outer ring insertion hole into which the outer ring can be inserted, and inserting the inner ring on which the coil spring is mounted into the outer ring, the inner ring is moved to the center. An assembly method comprising pressing in an axial direction and fitting a stepped groove portion of the inner ring into an inward protruding portion of the outer ring.