JP3933237B2 - Coaxial cylindrical torque limiter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coaxial cylindrical torque limiter, and more particularly to a coaxial cylindrical torque limiter that is improved so as to suppress rotation unevenness and enable smooth rotation.
[0002]
[Prior art]
FIG. 8 is an end view illustrating an example of a reverse roller for preventing double feed of a sheet feeding device using a conventional coaxial cylindrical torque limiter 500.
In the coaxial cylindrical torque limiter 500, the rotating shaft 31 is fitted around the metal shaft 31a. The rotating shaft 31 has a drum shape and is made of polyacetal resin (POM). In addition to the polyacetal resin, a polyamide resin (PA) is also used.
A cylindrical permanent magnet 52 is bonded to the outer periphery of the rotating shaft 31. The permanent magnet 52 is a neodymium bond magnet.
[0003]
The rotating cylinder 32 is made of a polyolefin resin such as a polyethylene resin, a polypropylene resin, or a polybutene resin.
A cylindrical semi-hard magnetic body 11 is fixed to the inner periphery of the rotary cylinder 32 by press-fitting. The semi-hard magnetic body 11 is made of an Fe—Cr—Co based magnetic material.
[0004]
The rotary shaft 31 and the rotary cylinder 32 are coaxially engaged so that the permanent magnet 52 and the semi-hard magnetic body 11 face each other with a gap A therebetween.
A cover 32a is attached to the rotating cylinder 32, and a rubber roller G is fitted therein.
[0005]
When the metal shaft 31a and the rotating shaft 31 rotate and the permanent magnet 52 rotates, hysteresis torque works between the permanent magnet 52 and the semi-hard magnetic body 11, and the rotating cylinder 32 rotates. The rubber roller G rotates. Then, the multi-feed paper is separated with a force corresponding to the hysteresis torque.
[0006]
FIG. 9 is a perspective view showing the semi-hard magnetic body 11 and the permanent magnet 52.
The semi-hard magnetic body 11 is formed by rounding a rectangular semi-hard magnetic plate, and a joint J2 (a portion where both ends of the plate abut each other) is parallel to the axial direction. A gap k is formed in the joint J2.
The permanent magnet 52 is magnetized so as to alternately form N pole and S pole magnetic pole regions parallel to the axial direction in the circumferential direction.
FIG. 10 is an explanatory view in which the periphery of the joint J2 is developed in a planar manner.
The direction of each magnetic pole region of the permanent magnet 52 is parallel to the direction of the joint J2.
[0007]
FIG. 11 is a perspective view showing a semi-rigid magnetic body 1 and a permanent magnet 52 according to another conventional example.
The semi-hard magnetic body 1 is formed by rolling a semi-hard magnetic body plate whose both ends are obliquely cut, and the joint J1 is inclined by an inclination angle α with respect to the axial direction.
FIG. 12 is an explanatory view in which the periphery of the joint J1 is developed in a planar manner.
The direction of each magnetic pole region of the permanent magnet 52 is inclined by an angle α with respect to the direction of the joint J1.
[0008]
The configurations of the semi-hard magnetic bodies 11 and 1 and the permanent magnet 52 described with reference to FIGS. 8 to 12 are disclosed in Japanese Patent Laid-Open No. 6-235447.
[0009]
[Problems to be solved by the invention]
In the conventional coaxial cylindrical torque limiter 500, the direction of each magnetic pole region of the permanent magnet 52 is parallel to the direction of the joint J2 of the semi-hard magnetic body 11, as shown in FIGS. Therefore, there is a problem that the hysteresis torque fluctuates every time the boundary between the magnetic poles passes through the joint J2, causing uneven rotation (pushing) and not rotating smoothly.
[0010]
On the other hand, in the semi-hard magnetic body 1 and the permanent magnet 52 shown in FIGS. 11 and 12, the direction of each magnetic pole region of the permanent magnet 52 is oblique with respect to the direction of the joint J1 of the semi-hard magnetic body 1. Although the fluctuation of the hysteresis torque when the boundary between the magnetic poles passes through the joint J1 is small, there is still a problem that the rotation unevenness (nodal movement) remains a little and does not rotate sufficiently smoothly. Further, the semi-hard magnetic body 1 of FIG. 11 has a problem that it is difficult to manufacture compared to the semi-hard magnetic body 11 of FIG.
[0011]
Therefore, the first object of the present invention is to sufficiently reduce the fluctuation in hysteresis torque when the boundary between each magnetic pole passes through the joint portion of the semi-hard magnetic material, to suppress rotation unevenness, and to rotate smoothly. An object of the present invention is to provide an improved coaxial cylindrical torque limiter.
The second object of the present invention is to provide a coaxial cylindrical type that has a structure that makes it easy to manufacture at the same time as reducing fluctuations in hysteresis torque and reducing rotation unevenness when the boundary between magnetic poles passes through the joint portion of a semi-hard magnetic material. It is to provide a torque limiter.
[0012]
[Means for Solving the Problems]
In a first aspect, the present invention includes a cylindrical semi-hard magnetic body having a seam inclined with respect to the axial direction and a seamless cylindrical permanent magnet, and the semi-hard magnetic body and the permanent magnet One is fixed to the outer periphery of the rotating shaft, the other is fixed to the inner periphery of the rotating tube, and the rotating shaft and the rotating tube are coaxially fixed so as to face each other with a gap therebetween. In the coaxial cylindrical torque limiter that transmits rotation between the rotating shaft and the rotating cylinder by the generated hysteresis torque, the permanent magnet is moved in a direction opposite to the inclination direction of the seam of the semi-hard magnetic body with respect to the axial direction. Provided is a coaxial cylindrical torque limiter characterized by being multipolarly magnetized in an oblique direction so as to form a magnetic pole region inclined in the direction.
In the coaxial cylindrical torque limiter according to the first aspect, the permanent magnet is magnetized so as to be a magnetic pole region inclined in the direction opposite to the inclination of the seam of the semi-hard magnetic material. The directions intersect at an intersection angle that combines the inclination of the seam and the inclination of each magnetic pole region. As a result, the crossing angle becomes larger than before, so the fluctuation of hysteresis torque when the boundary of each magnetic pole passes through the joint part of the semi-hard magnetic material is sufficiently small, rotation unevenness can be suppressed, and smooth enough You can rotate.
[0013]
In a second aspect, the present invention includes a cylindrical semi-hard magnetic body having a U-shaped seam and a seamless cylindrical permanent magnet, and the permanent magnet has a direction opposite to the U-shaped. Magnetized in the shape of an inverted letter so as to form a U-shaped magnetic pole region, one of the semi-hard magnetic body and the permanent magnet is fixed to the outer periphery of the rotating shaft, and the other is fixed to the inner periphery of the rotating cylinder And coaxially transmitting the rotation between the rotating shaft and the rotating cylinder by means of hysteresis torque generated between the rotating shaft and the rotating cylinder so as to face each other with a gap. A cylindrical torque limiter is provided.
In addition, it is quite equivalent even if the shape of the semi-rigid magnetic body is reversed, and the magnetic pole region of the permanent magnet is shaped like a dogleg. This is because it is just the difference seen upside down.
In the coaxial cylindrical torque limiter according to the second aspect, the permanent magnet is magnetized so as to be a magnetic pole region inclined in the direction opposite to the inclination of the seam of the semi-hard magnetic material. The directions intersect at an intersection angle that combines the inclination of the seam and the inclination of each magnetic pole region. As a result, the crossing angle becomes larger than before, so the fluctuation of hysteresis torque when the boundary of each magnetic pole passes through the joint part of the semi-hard magnetic material is sufficiently small, rotation unevenness can be suppressed, and smooth enough You can rotate. Further, it is possible to prevent the gap from expanding due to the seam being shifted vertically. For this reason, the stability of the hysteresis torque is further improved.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.
[0015]
-First embodiment-
FIG. 1 is an end view of a reverse roller for preventing double feed of a paper feeder using a coaxial cylindrical torque limiter 100 according to a first embodiment of the present invention.
In the coaxial cylindrical torque limiter 100, a rotating shaft 31 is fitted around a metal shaft 31a. The rotating shaft 31 has a drum shape and is made of polyacetal resin. In addition to the polyacetal resin, a polyamide resin is also used.
A cylindrical permanent magnet 2 is bonded to the outer periphery of the rotating shaft 31. The permanent magnet 2 is a neodymium bond magnet.
[0016]
The rotating cylinder 32 is made of a polyolefin resin such as a polyethylene resin, a polypropylene resin, or a polybutene resin.
A semi-rigid magnetic body 1 having a cylindrical shape obtained by rounding a plate-like member is press-fitted into the inner periphery of the rotating cylinder 32 and fixed by a spring elastic restoring force. The semi-hard magnetic body 1 is made of an Fe—Cr—Co based magnetic material. The semi-hard magnetic body 1 has dimensions of, for example, a diameter of 12 mm and a height of about 15 mm.
[0017]
The rotating shaft 31 and the rotating cylinder 32 are coaxially engaged so that the permanent magnet 2 and the semi-hard magnetic body 1 face each other with a gap A therebetween.
A cover 32a is attached to the rotating cylinder 32, and a rubber roller G is fitted therein.
[0018]
When the metallic shaft 31a and the rotating shaft 31 rotate and the permanent magnet 2 rotates, hysteresis torque works between the permanent magnet 2 and the semi-rigid magnetic body 1, the rotating cylinder 32 rotates, The rubber roller G rotates. Then, the multi-feed paper is separated with a force corresponding to the hysteresis torque.
[0019]
FIG. 2 is a perspective view showing the semi-hard magnetic body 1 and the permanent magnet 2.
The semi-hard magnetic body 1 is formed by rolling a semi-hard magnetic body plate whose both ends are cut obliquely, and the joint J1 is inclined leftward with respect to the axial direction by an inclination angle α. A gap k of about 0.5 mm is generated in the joint J1.
The permanent magnet 2 alternately forms N pole and S pole magnetic pole regions inclined in the circumferential direction by an inclination angle β (-β if the left is a positive direction) to the right with respect to the axial direction. Is so magnetized.
[0020]
FIG. 3 is an explanatory view in which the periphery of the joint J1 is developed in a planar manner.
Since the joint J1 is inclined by the inclination angle α and the direction of each magnetic pole region is inclined by the inclination angle −β, the crossing angle θ formed by the joint J1 and each magnetic pole region is (α + β), which is the conventional coaxial cylindrical torque. The crossing angle applied to the limiter 500 (α in the example of FIG. 12) is larger.
As a result, the fluctuation of the hysteresis torque when the boundary between the magnetic poles passes through the joint J1 is sufficiently small, so that the rotation unevenness can be suppressed and the rotation can be performed sufficiently smoothly.
[0021]
The inclination angle α is preferably as large as possible from the viewpoint of suppressing rotation unevenness. However, when the inclination angle α is excessively large, the joint J1 is liable to be displaced and difficult to manufacture. For this reason, it is preferable to determine the inclination angle α in the range of 0 ° <α ≦ 45 °.
In addition, the magnitude of the inclination angle β is desirably as large as possible from the viewpoint of suppressing rotation unevenness, but the hysteresis torque decreases as the inclination angle β increases. For this reason, it is preferable to determine the inclination angle β in the range of 0 ° <β ≦ 45 °.
In consideration of these, the crossing angle θ is preferably determined in the range of 10 ° ≦ θ ≦ 90 °, more preferably in the range of 30 ° ≦ θ ≦ 70 °.
For example, the inclination angle α = 30 °, the inclination angle β = 15 °, and the crossing angle θ = 45 °.
[0022]
According to the coaxial cylindrical torque limiter 100 described above, since the direction of each magnetic pole region of the permanent magnet 2 is inclined in the direction opposite to the inclination of the joint J1, the crossing angle θ between the joint J1 and each magnetic pole region increases, and the joint The fluctuation in hysteresis torque when the boundary between the magnetic poles passes through the portion of J1 becomes sufficiently small, so that the rotation unevenness can be suppressed and the rotation can be performed sufficiently smoothly.
[0023]
-Reference example-
FIG. 4 is a perspective view showing the semi-hard magnetic body 11 and the permanent magnet 2 used in the coaxial cylindrical torque limiter according to the reference example .
The semi-hard magnetic body 11 is formed by rounding a rectangular semi-hard magnetic body plate, and the joint J2 is parallel to the axial direction. A gap k of about 0.5 mm is generated at the joint J2.
The permanent magnet 2 alternately forms N pole and S pole magnetic pole regions inclined in the circumferential direction by an inclination angle β (-β if the left is a positive direction) to the right with respect to the axial direction. Is so magnetized.
[0024]
FIG. 5 is an explanatory view in which the periphery of the joint J2 is developed in a planar manner.
Since each magnetic pole region is inclined by the inclination angle β, the crossing angle formed by the joint J2 and each magnetic pole region is β, and the fluctuation of the hysteresis torque when the boundary between the magnetic poles passes through the joint J2 is reduced. Unevenness can be reduced and it can rotate smoothly.
[0025]
Although it is desirable to increase the inclination angle β as much as possible from the viewpoint of suppressing the rotation unevenness, the hysteresis torque decreases as the inclination angle β increases, so that an appropriate hysteresis torque can be obtained. It is preferable to determine the inclination angle β in the range of ° to 45 °. For example, the inclination angle β = 30 °.
[0026]
According to the above reference example, since the cylindrical semi-hard magnetic body 11 having the seam J2 parallel to the axial direction is used, it is easy to manufacture. Therefore, it is possible to reduce the variation in hysteresis torque when the boundary between the magnetic poles passes through the joint J2 of the semi-hard magnetic body 11, thereby reducing the rotation unevenness and at the same time making the structure easy to manufacture.
[0027]
- Second Embodiment -
FIG. 6 is an explanatory view showing the arrangement of the semi-hard magnetic body 21 and the permanent magnet 22 used in the coaxial cylindrical torque limiter according to the second embodiment of the present invention.
The semi-hard magnetic body 21 is formed so that one end of the semi-hard magnetic body plate is formed in the convex portion P, the other end is formed in the concave portion Q, and the convex portion P and the concave portion Q are fitted. It is formed by rolling a plate. The joint J3 is inclined with respect to the axial direction by an inclination angle α (when the left side is a positive direction, the upper side is + α and the lower side is −α). Further, a gap k of about 0.5 mm is generated at the joint J3.
The permanent magnet 22 alternately forms N pole and S pole magnetic pole regions that are bent in a "<" shape so as to have an inclination opposite to the inclination of the hypotenuse of the joint J3 in the circumferential direction. Is so magnetized. That is, each magnetic pole region is on the upper side and the lower side of the bend, and is inclined to the right and left by an inclination angle β with respect to the axial direction. It is leaning towards.
[0028]
FIG. 7 is an explanatory diagram in which the periphery of the joint J3 is developed in a planar manner.
Since the upper and lower sides of the joint J3 are inclined by the inclination angles + α and −α, and the magnetic pole regions are inclined by the inclination angles −β and + β on the upper and lower sides, the crossing angle θ formed by the joint J3 and the magnetic pole region is the upper side. The lower side is (α + β).
As a result, the fluctuation of the hysteresis torque when the boundary between the magnetic poles passes through the joint J3 is sufficiently small, rotation unevenness can be suppressed, and the rotation can be performed sufficiently smoothly.
[0029]
The inclination angle α is desirably as large as possible from the viewpoint of suppressing rotation unevenness, but if the inclination angle α is excessively large, the joint J3 is liable to be displaced and difficult to manufacture. For this reason, it is preferable to determine the inclination angle α in the range of 0 ° <α ≦ 45 °.
In addition, the magnitude of the inclination angle β is desirably as large as possible from the viewpoint of suppressing rotation unevenness, but the hysteresis torque decreases as the inclination angle β increases. For this reason, it is preferable to determine the inclination angle β in the range of 0 ° <β ≦ 45 °.
In consideration of these, the crossing angle θ is preferably determined in the range of 10 ° ≦ θ ≦ 90 °, more preferably in the range of 30 ° ≦ θ ≦ 70 °.
For example, the inclination angle α = 30 °, the inclination angle β = 15 °, and the crossing angle θ = 45 °.
[0030]
According to the second embodiment described above, since the semi-hard magnetic body 21 which is rounded by fitting the convex portion P and the concave portion Q is used, the joint J3 is vertically moved as compared with the first embodiment. It is possible to prevent the gap k from being enlarged by shifting. For this reason, the stability of the hysteresis torque is further improved.
[0031]
【The invention's effect】
According to the coaxial cylindrical torque limiter of the present invention, the permanent magnet is multipolarized so as to be a magnetic pole region inclined with respect to the seam of the semi-hard magnetic cylinder. The fluctuation of the hysteresis torque when passing through becomes sufficiently small, the rotation unevenness can be suppressed, and the rotation can be performed sufficiently smoothly.
In addition, according to the coaxial cylindrical torque limiter of the present invention, it is possible to reduce the hysteresis torque fluctuation when the boundary between the magnetic poles passes through the joint portion of the semi-hard magnetic material, thereby reducing the rotation unevenness and simultaneously making the structure easy to manufacture. I can do it.
[Brief description of the drawings]
FIG. 1 is an end view of a reverse roller for preventing double feed of a paper feeder using a coaxial cylindrical torque limiter according to a first embodiment of the present invention.
2 is an explanatory view showing the arrangement of semi-hard magnetic bodies and permanent magnets in the coaxial cylindrical torque limiter of FIG. 1; FIG.
FIG. 3 is an explanatory view showing the periphery of the joint of the coaxial cylindrical torque limiter of FIG. 1 in a plan view.
FIG. 4 is an explanatory diagram showing an arrangement of semi-hard magnetic bodies and permanent magnets in a coaxial cylindrical torque limiter according to a reference example .
FIG. 5 is an explanatory view showing the periphery of the joint of the coaxial cylindrical torque limiter of FIG. 4 in a plan view.
FIG. 6 is an explanatory view showing the arrangement of semi-hard magnetic bodies and permanent magnets in a coaxial cylindrical torque limiter according to a second embodiment of the present invention.
7 is an explanatory view showing the periphery of the joint of the coaxial cylindrical torque limiter of FIG. 6 in a plan view.
FIG. 8 is an end view showing an example of a reverse roller for preventing double feed of a paper feeder using a conventional coaxial cylindrical torque limiter.
9 is an explanatory view showing the arrangement of semi-hard magnetic bodies and permanent magnets in the coaxial cylindrical torque limiter of FIG.
10 is an explanatory view showing the periphery of the joint of the coaxial cylindrical torque limiter of FIG. 9 in a plan view.
FIG. 11 is an explanatory diagram showing the arrangement of semi-hard magnetic bodies and permanent magnets according to another example of a conventional coaxial cylindrical torque limiter.
12 is an explanatory view showing the periphery of the joint of the coaxial cylindrical torque limiter of FIG. 11 in a plan view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Coaxial cylindrical type torque limiter 1,11,21 Semi-hard magnetic body 2,22 Permanent magnet 31 Rotating shaft 31a Metal shaft 32 Rotating cylinder 32a Cover body A Gap G Rubber roller P Convex part Q Concave part α, β Inclination angle θ Intersection

Claims (2)

A cylindrical semi-hard magnetic body having a seam inclined with respect to the axial direction and a seamless cylindrical permanent magnet, and fixing one of the semi-hard magnetic body and the permanent magnet to the outer periphery of the rotating shaft; The other end is fixed to the inner periphery of the rotating cylinder, the rotating shaft and the rotating cylinder are coaxially fixed so that they are opposed to each other with a gap, and the rotating shaft and the rotation are rotated by a hysteresis torque generated therebetween. In a coaxial cylindrical torque limiter that transmits rotation between cylinders,
Coaxial cylindrical type characterized in that the permanent magnet is magnetized in an oblique direction so as to form a magnetic pole region inclined in a direction opposite to the inclination direction of the seam of the semi-hard magnetic material with respect to the axial direction. Torque limiter. It has a cylindrical semi-hard magnetic body having a U-shaped seam and a seamless cylindrical permanent magnet so that the permanent magnet becomes a U-shaped magnetic pole region opposite to the U-shaped Inverted multi-pole magnetized, one of the semi-hard magnetic body and the permanent magnet is fixed to the outer periphery of the rotating shaft, the other is fixed to the inner periphery of the rotating cylinder, and both are opposed to each other with a gap. A coaxial cylindrical torque limiter that coaxially fixes the rotating shaft and the rotating cylinder and transmits the rotation between the rotating shaft and the rotating cylinder by a hysteresis torque generated between them .

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