JPH0314922A - Torque limitter - Google Patents

Abstract

PURPOSE:To prevent the change of the deflection amount of a spring and ON- OFF torque by pressing rollers between clutch cam surfaces and inner members in a biting direction, and arranging holding faces of the spring on outer and inner rings. CONSTITUTION:A shaft 21 is, in general, rotated in a direction of an arrow A, then the rotation is transmitted to an outer ring 11 through rollers 15. When the shaft is rotated in a direction of an arrow B, the shaft 21 is run idly, so that rotation transmission to the outer ring 11 is interrupted. Thus, a clutch shows its function only in one direction. When a wedge angle of a clutch cam surface 12 and force of a spring 17 are adjusted, it is possible to set ON-OFF torque against the rotation of the shaft 21 in the direction of the arrow B. As a result, a one-way torque limitter which has function for preventing reverse rotation and can set a racing torque is constructed. Housing parts 23 are directly formed on the outer ring 11 continuously to the clutch cam surfaces 12. The end of the housing part 12 is the holding face 18 of the spring 17, so that the distance between the roller 15 and the holding face 18 of the spring 17 is kept constant, and the change of the ON-OFF torque is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a torque limiter that transmits and cuts off rotational torque, and more specifically, to a mechanism for preventing double feeding in a paper feed roller section of office automation equipment, tapes, ribbons, etc. This article relates to a torque limiter that can be used as a tension brake for feeding mechanisms such as sheets. [Prior Art] As a torque limiter, a powder torque limiter and a spring clutch type torque limiter are generally known.

However, while the former torque limiter has the advantage of being highly functional, it has the disadvantage of being expensive due to its complicated mechanism and being inconvenient to handle since it is integrated with the shaft.

Furthermore, the latter torque limiter has the disadvantage of large variations in on/off torque and short life.

In order to eliminate these drawbacks, the present applicant has utilized the basic structure of a one-way crunch to achieve low manufacturing costs and on-the-job processing.
Application for torque converter with stable off-torque 1986-5
Proposed by No. 5348. As shown in FIG. 7, the above torque limiter incorporates a resin retainer 3 inside an outer tube 2 having a plurality of craniometric cam surfaces 1 on its inner circumferential surface, and each cam surface of the retainer 3 1
An S-shaped spring 6 is used to hold the rollers 4 at a position corresponding to the retainer 3 and press the rollers 4 in the biting direction between the clutch cam surface 1 and the shaft 5 inserted into the retainer 3. A storage portion 7 is provided, and the wedge angle of the taranti cam surface on which the spring force of the spring 6 acts is set so that on/off torque is generated with respect to the rotation of the shaft 5. [Problem to be Solved by the Invention] By the way, when the S-shaped spring 6 that presses the roller 4 is supported by a resin retainer 3 incorporated into the outer ring 2, when the spring force of the spring 6 is increased, Another problem is that the spring height, that is, the amount of deflection of the spring changes due to the influence of dimensional variations and deformation of the outer ring 2 and cage 3, causing fluctuations in on/off torque.

Therefore, an object of the present invention is to provide a torque limiter that maintains a constant distance between the roller and the spring holding surface and does not cause fluctuations in on/off torque, in order to solve the above-mentioned problems. [Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an inner member inside an outer ring having a plurality of clutch cam surfaces on its inner circumferential surface, and a clutch cam of the outer ring. A structure is adopted in which a roller is incorporated between the surface and the inner member, and a spring holding surface is provided in the outer ring to press the roller in the biting direction between the cranochicam surface and the inner member. be.

[Effect]

Incorporate rollers between the clutch cam surface of the outer ring and the inner member,
Since a spring holding surface that presses in the biting direction between the clutch cam surface and the inner member is provided in the outer ring, the distance between the rollers and the spring holding surface can be kept constant, and the spring deflection can be maintained. There is no change in the amount, and fluctuations in on/off torque can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6 of the accompanying drawings.

As shown in the figure, the basic configuration of the torque limiter is the same as that of a one-way clutch, and clutch cam surfaces 12 are provided at multiple positions on the inner peripheral surface of the outer ring 11, and a retainer 13 is provided inside the outer ring 11. The inner ring 14 is inserted inside this retainer 13, and each clutch cam surface 12 of the retainer 13 and the inner ring 14 are
The rollers 15 are stored in the pockets 16 of the retainer 13 and tied in between, and the springs 17 are held in the outer ring 11 to press the rollers 15 in the biting direction between the clutch cam surface 12 and the inner ring 14. It has a structure in which a surface 18 is provided.

Note that one end of the outer ring 11 is connected to a presser foot 1 that is fitted onto the inner ring 14.
19, and a presser foot M1 is provided on the outer periphery of the outer ring 11.
External resin part 2 covering the outer periphery of S and the other end of the foreign material 11
0 is fixed, and the inner ring 14 is coupled with a pin 22 so as to rotate together with the inserted shaft 21.

In the illustrated case, the inner member is a combination of the shaft 21 and the inner ring 14 fitted onto the shaft, but the structure is such that the inner ring 14 is omitted and only the shaft 21 is used, and the stiffener 15 etc. are incorporated between the outer ring 11 and the shaft 21. may be adopted.

In the basic structure as described above, when the shaft 21 normally rotates in the direction of arrow A in FIG. Then, the shaft 21 idles and rotation transmission to the outer ring 11 is cut off, resulting in a function as a one-way clutch.

Using the basic structure described above, by adjusting the wedge angle of the clutch cam surface 12 and the spring force of the spring 17, the pongee 21
For rotation in the direction of arrow B, it is possible to set on/off torque, and as a result, it is possible to configure a one-way torque limiter with a reverse rotation prevention function that allows setting of idling torque.

By the way, the metal outer ring 11 is directly connected to the clutch cam surface 12 and has a storage section 23 for the spring 17, and the end of this storage section 23 serves as the holding surface 18 for the spring 17, so that the rollers 15 and the spring The distance between the spring 17 and the holding surface 18 is kept constant, the spring force of the spring 17 that presses the roller 15 becomes constant, and fluctuations in on/off torque can be prevented.

Furthermore, by incorporating the inner ring 14 inside the outer ring 11,
As shown in Fig. 2, if the inner ring 14, presser cover 19, and outer resin part 20 are combined, it becomes a sealed torque grip at the time of manufacture, preventing grease leakage and dust intrusion, and reducing on/off torque. It can be stabilized for a long period of time.

In order to reduce fluctuations in the on/off torque of the torque limiter, the roughness of the mating contact surface with the rollers 15 is important, and by using the inner ring 14 in combination, the surface roughness of the outer diameter surface of the inner ring can be controlled. be able to.

As shown in FIG. 2, the inner ring 14 and the shaft 21 are connected by a pin 22 that has notches 31 on both sides of the shaft center at the end of the inner ring 14 and passes through the shaft 21 in the radial direction. By fitting the notches 31 at both ends, they are integrated in the rotational direction.

5 and 6 show an example in which a ring 32 is externally fitted and fixed on the outer periphery of a portion where a notch 31 is provided at the end of the inner ring 14 in order to prevent the pin 22 from coming off. This ring 32 is shaped using resin, and the inner ring 1
4 by press-fitting or gluing, and the pin 22 is prevented from coming out. In the torque limiter described above, when the outer ring 11 is a common component, the on/off torque is determined by the spring force of the spring 17,
Although it is determined by the diameter of the rollers 15 and the outer diameter of the inner ring 14, the required on/off torque differs depending on the user, and if each component is designed individually, a problem arises in that the number of types of parts increases. In contrast, several types of springs 17 with different spring forces are prepared, with the other parts except the spring 17 being common parts, and
By preparing rollers 15 and inner ring 14 with slightly different dimensions, it is possible to meet various required on/off torques with a small number of types of parts, and by providing inner ring 14, there is greater freedom in torque setting during manufacturing. becomes larger, allowing detailed torque management. Fig. 4 shows an example of a torque setting method, and the solid line in the figure shows, for example, when an inner ring 14 with an outer diameter D is used and a spring height H is used, a spring 17 whose on/off torque can be set to 300 gf-cm is used. Suppose you are doing so.

Under these conditions, the on/off torque is 280g.
If there is a request for f-CI, the spring force can be reduced.

Therefore, as shown by the broken line in the figure, the outer diameter D. All you have to do is combine the inner rings 14 of . In the torque setting method shown in FIG. 4, the torque is adjusted by changing the outer diameter of the inner ring 14, but the same adjustment can be made by changing the diameter of the rollers 15.

In addition, if the torque value of the torque limiter is outside the standard during the final inspection, it is recommended to prepare an inner ring with a different outer diameter, and the same method can be used to adjust the torque value to within the standard. As described above, according to the present invention, since the spring holding surface that presses the roller in the biting direction between the clutch cam surface and the inner member is provided in the outer ring, the roller and the spring holding surface are The distance is kept constant, the amount of deflection of the spring does not change, and there are no fluctuations in on/off torque.

Further, when the inner ring is used in combination as the inner member, by combining the spring with the spring and the inner ring of different sizes, it is possible to meet various required on/off torques with a small number of types of parts.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a torque limiter according to the present invention;
Fig. 2 is a vertical side view of the same, Fig. 3 is an exploded perspective view of the main parts of the same, Fig. 4 is an explanatory diagram of the torque setting method, and Fig. 5 is a longitudinal side view showing the mechanism to prevent the pin connecting the inner ring and the shaft from falling out. 6 is an exploded perspective view of the same as above, and FIG. 7 is a longitudinal sectional front view showing a conventional torque limiter. 11... Outer ring, 12... Clutch cam surface, 13... Retainer, 14
...Inner circle, 15...Koro,
17... Spring, 18... Spring holding surface.

Claims (1)

[Claims] (1) An inner member is provided inside an outer ring having a plurality of clutch cam surfaces on the inner circumferential surface, and a roller is installed between the clutch cam surface of the outer ring and the inner member, and this roller is connected to the clutch cam surface and the inner member. A torque limiter that has a spring holding surface inside the outer ring that presses in the biting direction between the outer ring and the outer ring.