JP6750073B1 - Torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastener for fastening an inner ring and an outer ring even when a relatively large rotational torque is applied, or when a relatively large rotational torque is applied to relatively rotate the inner ring and the outer ring. To provide a new connecting member capable of stably maintaining the function of the torque limiter as a mechanical component, and to provide a new torque limiter using a connecting member that has achieved the above problems. SOLUTION: A connecting member 8 configured so that two upright walls 20 adjacent to each other in the circumferential direction are close to each other or in contact with each other is arranged between an inner ring 4 and an outer ring 6. [Selection diagram] Fig. 1

Description

The present invention includes a shaft-like inner ring, is disposed between the outer ring inner ring is inserted, relative to the inner ring and the outer ring when a relative rotational torque less than a predetermined value is applied between the inner ring and the outer ring it relates torque limiter with connection member which rotated.

It is arranged between the outer peripheral surface of the shaft-shaped inner ring and the inner peripheral surface of the outer ring through which the inner ring is inserted, and (1) fastens the inner ring and the outer ring, or (2) a predetermined value or more between the inner ring and the outer ring. As an example of a connecting member that relatively rotates the inner ring and the outer ring when the relative rotation torque of 1 is applied, a mechanical component called a tolerance ring has already been widely put into practical use. The tolerance ring is a strip-shaped thin plate elastic piece having a substantially C-shaped cross section, which is press-fitted between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, so that the inner ring and the outer ring have (1) or (2). It will operate as follows. When the tolerance ring is used as in (1), it functions as a fastener, and when used as in (2), it functions as a mechanical component of a torque limiter. An example of such a tolerance ring is disclosed in Patent Document 1 below.

Usually, the tolerance ring is formed by rolling a strip-shaped thin plate material in the longitudinal direction into an annular shape. The tolerance ring and the inner ring and the outer ring are combined by pressing the inner ring into the tolerance ring after the outer ring and the tolerance ring are combined.

On the other hand, Patent Document 2 below includes an inner ring, an outer ring through which the inner ring is inserted, and a connecting member arranged between the inner ring and the outer ring, wherein the inner ring, the outer ring, and the connecting member are The connecting member has a common central axis, the connecting member includes an end plate axially opposed to an end surface of the inner ring, and a plurality of standing walls standing axially from an outer peripheral edge of the end plate. Each of the walls is provided at intervals in the circumferential direction, the inner peripheral surface of the standing wall is in close contact with the outer peripheral surface of the inner ring, and the outer peripheral surface of the standing wall is in close contact with the inner peripheral surface of the outer ring, respectively, and the outer ring. When a rotational torque about the central axis that relatively rotates the inner ring is applied, between the inner peripheral surface of the upright wall and the outer peripheral surface of the inner ring when the rotational torque is larger than a predetermined value. There is disclosed a torque limiter in which the outer ring and the inner ring rotate relative to each other by overcoming the friction force between the outer wall of the upright wall and the inner peripheral surface of the outer ring. In the following description, the predetermined value of the rotation torque may be referred to as "slip torque value".

Japanese Patent No. 5331879 JP, 2015-209869, A

The tolerance ring as disclosed in Patent Document 1 is formed by rolling a strip-shaped thin plate material into a C-shape by rolling it in the longitudinal direction. It is necessary to wind the plate material at 360 degrees or more to give a so-called bending habit, and such processing is complicated.

In the connecting member disclosed in Patent Document 2 described above, the two standing walls that are adjacent to each other in the circumferential direction are largely separated from each other in the circumferential direction. Therefore, in the torque limiter including this, when a relatively large rotational torque about the central axis that relatively rotates the inner ring and the outer ring is applied, the inner peripheral surface of the standing wall and the outer peripheral surface of the inner ring are The standing wall is tilted in the circumferential direction due to the frictional force between the standing wall and the frictional force between the outer circumferential surface of the standing wall and the inner circumferential surface of the outer ring, and the above-described predetermined value of the rotational torque (that is, the slip torque value) is stable. Without doing so, there is a possibility that the performance as the torque limiter cannot be fully exhibited. Further, there is a possibility that the standing wall of the connecting member may fall and be caught between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, completely stopping the function as the torque limiter. Further, since the connecting member and the outer ring are coupled to each other in a non-rotatable manner by the engagement of the notch and the groove, it is necessary to align the two when they are combined, and such work is complicated.

The present invention has been made in view of the above disclosure and its principal object is the inner ring and the outer ring and relatively rotated to relatively large rotational torque mechanism of the torque limiter even if granted it is to provide a new and improved torque limiter using the connection member capable of maintaining the function as part stably.

As a result of earnest studies, the present inventor has arranged the connecting member configured so that two standing walls adjacent to each other in the circumferential direction come close to or abut each other between the inner ring and the outer ring. Found to be resolved.

According to the present invention , as a torque limiter for achieving the above-mentioned main technical problem, a shaft-shaped inner ring, an outer ring through which the inner ring is inserted, and a connecting member arranged between the inner ring and the outer ring are provided. ,
The inner ring, the outer ring and the connecting member have a common central axis,
The connection member includes an end plate that axially faces the end surface of the inner ring, and a plurality of standing walls that stand upright in the axial direction from the outer peripheral edge of the end plate,
Each of the standing walls is provided in parallel in the circumferential direction, the inner peripheral surface of the standing wall and the outer peripheral surface of the inner ring, the outer peripheral surface of the standing wall is in close contact with the inner peripheral surface of the outer ring, respectively.
When a rotational torque around the central axis that relatively rotates the outer ring and the inner ring is applied, when the rotational torque is larger than a predetermined value, the inner peripheral surface of the upright wall and the outer peripheral surface of the inner ring. In a torque limiter in which the outer ring and the inner ring relatively rotate by overcoming the frictional force between the outer wall surface of the upright wall and the inner peripheral surface of the outer ring,
A torque limiter is provided in which two standing walls that are circumferentially adjacent to each other are close to or abut against each other.

Preferably, a supporting piece that projects in the circumferential direction is provided on the circumferential side surface of the standing wall, and the supporting piece approaches or abuts the standing wall that is adjacent in the circumferential direction. In this case, it is preferable that the support piece is provided at the extending end portion of the standing wall. Further, it is preferable that the supporting pieces are provided on all of the upstanding walls, and that any of the supporting pieces projects to one side in the circumferential direction. It is preferable that the inner wall surface of the upright wall is formed with a protruding portion that projects radially inward and is in close contact with the outer peripheral surface of the inner ring. Suitably, the said protrusion part is extended in an axial direction, and a cross section is an arc-shaped protrusion. The outer ring includes an end wall that axially faces the end plate of the connecting member, and the end plate of the connecting member is sandwiched between the end surface of the inner ring and the end wall of the outer ring. Is preferred.

In the preparative Rukurimitta of the present invention, that the two upstanding walls adjacent in the circumferential direction come close to contact, relatively large rotational torque around the central axis o for relatively rotating the inner and outer rings are added Even in such a case, the standing wall is prevented from tilting in the circumferential direction, and the slip torque between the inner ring and the outer ring can be stably maintained without damaging the connecting member.

The figure which shows the suitable embodiment of the torque limiter comprised according to this invention. The figure which shows the connecting member of the torque limiter shown in FIG. 1 alone. The figure which shows the connection base material press-fitted inside an outer ring with an inner ring alone. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. FIG. 3 is a diagram showing an assembly process of the torque limiter shown in FIG. 1. The figure which shows the 1st modification of a connection base material. The figure which shows the 2nd modification of a connection base material.

Hereinafter, with reference to the accompanying drawings which illustrate a preferred embodiment of the configured preparative Rukurimitta accordance with the present invention will be described in detail.

First, a preferred embodiment of a torque limiter constructed according to the present invention will be described with reference to FIGS. 1 and 2.

Referring to FIG. 1, a torque limiter, generally designated by reference numeral 2, constructed in accordance with the present invention includes an inner ring 4, an outer ring 6 and a connecting member 8. The inner ring 4, the outer ring 6, and the connecting member 8 have a common central axis o, and in the illustrated embodiment, all are made of metal.

The inner ring 4 is a solid rod-shaped shaft member having a circular cross section. The outer ring 6 has a bottomed cylindrical shape, and the cross section of the inner peripheral surface is also circular. One end of the outer ring 6 in the axial direction is open, and the other end of the inner ring 2 in the axial direction is inserted inside the outer ring 6. An engaging portion (not shown) connected to an appropriate driving source such as a motor or a driven member is provided on one end portion of the inner ring 4 in the axial direction and the other end surface of the outer ring 6 in the axial direction.

Referring to FIG. 2 together with FIG. 1, the connecting member 8 includes an end plate 18 that is substantially perpendicular to a common central axis o, and a plurality of standing members that extend axially from the outer peripheral edge of the end plate 18. The wall 20 is included. Although the method of forming the connecting member 8 will be described later, in the illustrated embodiment, the end plate 18 is a substantially regular octagon that is slightly larger than the axial end surface of the inner ring 4, and the upright wall 20 is the end plate 18. The central portion of each side (which is indicated by reference numeral 18a) extends linearly in the axial direction with the base end edge 22. In other words, eight standing walls 20 are provided at equal intervals in the circumferential direction. The extending end edge 24 of the standing wall 20 has an arcuate shape that is convex from the base end edge 22 toward the extending end edge 24 when viewed in the axial direction (this will also be described later). A projecting portion 26 projecting radially inward is formed on the inner peripheral surface of the standing wall 20. The projecting portion 26 extends linearly in the axial direction, and its cross section is an arcuate ridge. On the back side of the protrusion 26, a recess is formed along the protrusion.

In the torque limiter of the present invention, it is important that the two standing walls 20 adjacent to each other in the circumferential direction are close to or in contact with each other. In the illustrated embodiment, the standing wall 20 has a base portion 22 at the central portion of each side 18 a of the end plate 18, and the base edge 22 of the standing wall 20 is shorter than each side 18 a of the end plate 18. A supporting piece 28 projecting to one side in the circumferential direction is provided on one side surface in the circumferential direction of the extending end of all the standing walls 20, and the two standing walls 20 adjacent to each other in the circumferential direction are provided with the supporting pieces 28. A gap 30 is formed in a portion which is close to or abuts with the support piece 28 and is not provided. Here, it is not always necessary that the two standing walls 20 adjacent to each other in the circumferential direction come into contact with each other, and there is a slight gap between them so that the standing walls 20 are prevented from tilting in the circumferential direction. You may have. Assuming that the length of one side 18a of the end plate 18 is X, the circumferential distance between the two standing walls 20 adjacent to each other in the circumferential direction is about 0 to 5% of X at the portion where the support piece 28 is provided, In the region where the support piece 28 is not provided (that is, the gap in the circumferential direction of the gap 30) is preferably about 5 to 40% of X. The support piece 28 may be omitted if desired. When the support piece 28 is omitted, it is preferable that the circumferential interval between the two standing walls 20 adjacent to each other in the circumferential direction be about 0 to 40% of the above X.

Referring to FIG. 1, when the inner ring 4, the outer ring 6 and the connecting member 8 are assembled as required (the assembling process will be described later), the end plate 18 of the connecting member 8 forms an axial end surface of the inner ring 4. It is sandwiched between the outer ring 6 and the axial end wall of the outer ring 6, and the inner peripheral surface of the standing wall 20 (the projecting portion 26 in the illustrated embodiment) is the outer peripheral surface of the inner ring 4, and the outer peripheral surface of the standing wall 20 is the inner ring of the outer ring 6. Close contact with the surrounding surface. Then, when the rotation torque around the central axis o for relatively rotating the outer ring 6 and the inner ring 4 is applied, and the rotation torque is equal to or less than a predetermined value, the outer ring 6, the inner ring 4, and the connecting member 8 are integrated. When the rotation torque is larger than a predetermined value, the frictional force between the inner peripheral surface of the upright wall 20 and the outer peripheral surface of the inner ring 4 or the outer peripheral surface of the upright wall 20 and the inner peripheral surface of the outer ring 6 is increased. The outer ring 6 and the inner ring 4 rotate relative to each other by overcoming the frictional force between the outer ring 6 and the inner ring 4.

In the torque limiter of the present invention, the two standing walls 20 adjacent to each other in the circumferential direction are brought close to or in contact with each other, thereby relatively rotating torque about the central axis o for relatively rotating the inner ring 4 and the outer ring 6. Even when the vertical wall 20 is added, the standing wall 20 is prevented from tilting in the circumferential direction, and the sliding torque between the inner ring 4 and the outer ring 6 is stably maintained without damaging the connecting member 8. Is possible.

In the illustrated embodiment, the connecting member 8 is used as a component of the torque limiter 2. However, the material of the connecting member and the axial protrusion amount of the protruding portion are appropriately adjusted so that the connecting member and the inner ring and the outer ring can be more closely connected. It can also be used as a fastener for fastening the inner ring 4 and the outer ring 6 by firmly and closely contacting each other.

Next, an assembling method of the torque limiter shown in FIG. 1 will be described with reference to FIGS. 3 and 4.

First, the inner ring 4 and the outer ring 6 are formed by appropriate machining, and the connection base material 32 having a required shape is formed. The connection base material 32 will be described with reference to FIG. 3. The connection base material 32 includes a ring-shaped central portion 34 and a plurality of (in the illustrated embodiment, 8) radial outwards from the outer peripheral edge of the central portion 34. Individual) extending pieces 36, and is formed by pressing an appropriate thin plate material. The extension pieces 36 are arranged at equal intervals in the circumferential direction, and a required arcuate gap 37 is provided between the base ends of the two extension pieces 36 adjacent in the circumferential direction. There is. The outer peripheral edges of all the extending piece portions 36 are a part of a common virtual circle 38 shown by a chain double-dashed line in FIG. 3, and the center of the virtual circle 38 coincides with the center of the connecting base material 32. The extending piece portion 36 corresponds to the standing wall 20 of the connecting member 8. Although not described by giving numbers, the respective extending piece portions 36 are also formed with portions corresponding to the projecting portions 26 and the supporting pieces 28 of the connecting member 8.

Subsequently, a step of combining the inner ring 4 and the outer ring 6 with the above-mentioned connection base material 32 will be described with reference to FIG. As shown in FIG. 4A, the inner ring 4, the outer ring 6, and the connection base material 32 are arranged on a common central axis o. In the illustrated embodiment, the outer ring 6 and the connecting base material 32 are supported by a cylindrical jig generally denoted by reference numeral 40. The jig 40 includes an insertion hole 42 into which the outer ring 6 can be inserted in the vertical direction, and an annular positioning protrusion 44 surrounding the insertion hole 42 on the upper surface and having the same center as the insertion hole 42. .. The inner diameter of the insertion hole 42 corresponds to the outer diameter of the outer ring 6, the inner diameter of the positioning protrusion 44 corresponds to the outer diameter of the connection base material 32, that is, the inner diameter of the virtual circle 38, and the axial length of the jig 40 is the outer ring. 6 longer than the axial length (see FIG. 4-2(b)). As shown in FIG. 4-2, such a jig 40 is fixed to the floor surface, the outer ring 6 is inserted into the insertion hole 42, and the connection base material 32 is placed on the upper surface inside the positioning protrusion 44. It At this time, since the axial length of the jig 40 is longer than the axial length of the outer ring 6, when the connection base material 32 is placed on the upper surface of the jig 40, the connection base material 32 and the outer ring 6 are placed. It will be separated from 6 in the axial direction.

When the inner ring 4 is lowered from the state shown in FIG. 4-2, the axial end surface of the inner ring 4 comes into contact with the central portion 34 of the connection base material 32, as shown in FIG. 4-3. From the state shown in FIG. 4-3, when the axial end surface of the inner ring 4 is pressed against the central portion 34 of the connection base material 32 to further lower (force) the inner ring 4, as shown in FIG. 4-4. The extending piece portion 36 stands upright with respect to the central portion 34, that is, the extending piece portion 36 inclines upward in the radial direction from the base end toward the extending end. At this time, the axial length of the jig 40 is longer than the axial length of the outer ring 6, and the connecting base material 32 and the outer ring 6 are axially separated from each other. By the principle of the so-called leverage with the outer peripheral edge of the insertion hole 42 as a fulcrum, it can be made to stand upright easily with respect to the central portion 34. Then, when the inner ring 4 is further lowered (forced) from the state shown in FIG. 4-4, first, the inner ring 4 is press-fitted inside the outer ring 6 together with the central portion 34 of the connection base material 32, and then the extension is performed. The piece portion 36 is gradually press-fitted inside the outer ring 6 from the base end edge toward the extended end edge. At this time, since the extending piece portion 36 of the connecting base material 32 stands upright with respect to the central portion 34, the extending piece portion 36 when the central portion 34 is press-fitted inside the outer ring 6 together with the inner ring 4. Acts as a guide, so that the inner ring 4 and the central portion 34 of the connection base 32 are press-fitted into the outer ring 6 sufficiently smoothly. The extension piece portion 36 of the connection base 32 has a larger inclination angle with respect to the center portion 34 as the center portion 34 moves downward, and finally becomes substantially parallel to the axial direction and the inner circumference of the extension piece portion 36. The outer peripheral surface of the inner ring 4 and the outer peripheral surface of the extending piece portion 36 come into close contact with the inner peripheral surface of the outer ring 6, respectively. Then, as shown in FIGS. 4-5, when the central portion 34 of the connection base material 32 comes into contact with the axial end surface of the outer ring 6, the lowering of the inner ring 4 and the connection base material 23 is stopped, and the connection member 8 is formed. It will be. Thus, the torque limiter 2 of the present invention is completed. After that, the jig 40 is removed.

In the torque limiter shown in FIG. 1, the thin plate-like connecting base material 32 having a required shape is press-fitted inside the outer ring 6 together with the inner ring 4, so that the connecting member 8 is formed and at the same time the inner ring 4 is formed. It is arranged between the outer peripheral surface and the inner peripheral surface of the outer ring 6. Therefore, the complicated work of individually erecting the extending piece portions 36 of the connecting base material 32 to form the connecting member 8 is not necessary, and the inner ring 4, the outer ring 6, and the connecting member 8 can be properly pressed in once. Since it is assembled, the torque limiter can be manufactured quickly and the manufacturing cost thereof can be reduced. Furthermore, in the illustrated embodiment, since the extending piece portions 36 are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the central portion 34, the extending piece portions 36 stand upright with respect to the central portion 34. In doing so, the gap 30 is formed, and it is possible to prevent the two extending piece portions 36 (or the standing wall 20) adjacent to each other in the circumferential direction from interfering excessively.

Although the preparative Rukurimitta of the present invention has been described in detail with reference to the accompanying drawings, bets Rukurimitta of the present invention is not limited to the embodiments described above, various modifications can be considered. For example, in the above-described embodiment, the connection base material 32 has the shape shown in FIG. 4, but it may have a shape as shown in FIGS. 5 and 6 instead. When the connection base material has the shape shown in FIG. 5 (this is shown by the numeral 32'), the support piece (28') is not provided on one side surface in the circumferential direction of all the standing walls (20'), Every other standing wall (20') in the circumferential direction projects to both sides in the circumferential direction. Further, the protruding portion (26') is formed by a plurality of hemispheres that extend in the axial direction and are not arc-shaped ridges in cross section, but are arranged at intervals in the axial direction. When the connecting base material has the shape shown in FIG. 6 (this is indicated by the numeral 32″), the protrusion (26″) extends in the axial direction, but its cross section has a V-shape. ing. Further, in the illustrated embodiment, the protruding portion 26 provided on the upright wall 20 of the connecting member 8 is in close contact with the outer peripheral surface of the inner ring 4, but the protruding portion is in close contact with the inner peripheral surface of the outer ring 6. You may do it. Furthermore, when the slip torque value is set to be relatively small, the protrusion 26 provided on the upright wall 20 of the connection member 8 may not be provided. In this case, the base end edge of the inner peripheral surface of the standing wall 20 comes into close contact with the base end edge of the outer peripheral surface of the inner ring 4.

2: Torque limiter 4: Inner ring 6: Outer ring 8: Connection member 20: Standing wall 26: Projection part 28: Support piece 32: Connection base material 40: Jig

Claims (7)

A shaft-shaped inner ring, an outer ring through which the inner ring is inserted, and a connecting member arranged between the inner ring and the outer ring,
The inner ring, the outer ring and the connecting member have a common central axis,
The connection member includes an end plate that axially faces the end surface of the inner ring, and a plurality of standing walls that stand axially from the outer peripheral edge of the end plate,
Each of the standing walls is provided in parallel in the circumferential direction, the inner peripheral surface of the standing wall and the outer peripheral surface of the inner ring, the outer peripheral surface of the standing wall is in close contact with the inner peripheral surface of the outer ring, respectively.
When a rotational torque around the central axis that relatively rotates the outer ring and the inner ring is applied, when the rotational torque is larger than a predetermined value, the inner peripheral surface of the upright wall and the outer peripheral surface of the inner ring. In a torque limiter in which the outer ring and the inner ring relatively rotate by overcoming the frictional force between the outer wall surface of the upright wall and the inner peripheral surface of the outer ring,
A torque limiter characterized in that the two standing walls that are adjacent to each other in the circumferential direction come close to or abut. Wherein the circumferential side surface of the upright wall, supporting pieces projecting in the circumferential direction is provided, close to contact with the upright wall the support piece adjacent to each other in the circumferential direction, the torque limiter of claim 1. The torque limiter according to claim 2 , wherein the support piece is provided at an extending end portion of the upright wall. The torque limiter according to claim 2 or 3 , wherein the support pieces are provided on all of the upstanding walls, and any of the support pieces protrudes to one side in the circumferential direction. The torque limiter according to any one of claims 1 to 4 , wherein a protruding portion that protrudes radially inward and is in close contact with the outer peripheral surface of the inner ring is formed on the inner peripheral surface of the standing wall. The torque limiter according to claim 5 , wherein the projecting portion extends in the axial direction, and is a ridge having an arc-shaped cross section. The outer ring includes an end wall that axially faces the end plate of the connection member,
Wherein said end plate of the connecting member is sandwiched the end face of the inner ring and by said end wall of said outer ring, the torque limiter according to any one of claims 1 to 6.