The present disclosure relates to a limit switch.
Patent Document 1 discloses a limit switch provided with a housing in which a built-in switch is housed. This limit switch includes a shaft extending from the outside to the inside of the housing and pivotably supported by the housing, and an arm that is connected to the end of the shaft on the outer side of the housing and can pivot the shaft.
Patent Document 1: JP 2015-204223 A
In the limit switch, when an external force is applied to the arm from the extending direction of the shaft, the shaft may be deformed and the limit switch may break down.
An object of the present disclosure is to provide a limit switch that prevents deformation of a pivoting shaft and is less likely to break down.
An example of a limit switch of the present disclosure is provided with:
a switch body having a contact mechanism inside; and
an operation unit connected to the switch body.
The operation unit includes
a housing body connected to the switch body,
a pivoting shaft extending from an outside of the housing body to an inside of the housing body and pivotable around an extending direction of the pivoting shaft,
a bearing that is provided in the housing body and pivotably supports the pivoting shaft, and
an operation lever that extends in a direction intersecting with the pivoting shaft, is connected to the pivoting shaft outside the housing body, and pivots the pivoting shaft to turn on and off the contact mechanism.
The operation unit includes
a cylindrical peripheral wall surrounding the bearing around the pivoting shaft outside the housing body, and
a pivoting shaft support that is provided in the extending direction of the pivoting shaft within the peripheral wall at a position further away from the inside of the housing body than the bearing around the pivoting shaft, permits pivoting of the pivoting shaft with respect to the housing body in a state of an external force along the extending direction of the pivoting shaft being not applied to the operation lever, and contacts the peripheral wall to support the pivoting shaft in a state of the external force along the extending direction of the pivoting shaft being applied to the operation lever.
According to the limit switch, the operation unit includes a pivoting shaft support that permits pivoting of the pivoting shaft with respect to the housing body in a state of an external force along the extending direction of the pivoting shaft being not applied to the operation lever, and contacts the peripheral wall to support the pivoting shaft in a state of the external force along the extending direction of the pivoting shaft being applied to the operation lever. The pivoting shaft support can prevent deformation of the pivoting shaft due to an external force along the extending direction of the pivoting shaft, so that a limit switch that is less likely to break down can be achieved.
Hereinafter, an example of the present disclosure will be described with reference to the accompanying drawings. In the following description, terms indicating specific directions or positions (e.g., terms including “up,” “down,” “right,” and “left,”) will be used as necessary, but the use of those terms is to facilitate understanding of the present disclosure with reference to the drawings, and the technical scope of the present disclosure is not limited by the meanings of those terms. The following description is essentially mere illustration and does not intend to restrict the present disclosure, its application, or its use. Further, the drawings are schematic, and the ratio of each dimension, or the like, does not necessarily match an actual one.
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Note that the sealer 13 is provided within the peripheral wall 12 and at the end of the housing body 11, the end being farther from the inside than the bearing 30 in the extending direction of the pivoting shaft 20. The sealer 13 is configured by, for example, an oil seal, and seals the inside of the housing body 11.
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On the other hand, when an external force in the circumferential direction with respect to the pivoting axis L is applied to the operation lever 40, the operation lever 40 pivots together with the pivoting shaft 20 from the return position P1 to the first motion position P2 or the second motion position P3. By the pivoting of the operation lever 40, a first cam 61 and a second cam 62 to be described later, which are connected to the pivoting shaft 20, pivot and the contact mechanism in the switch body 2 is switched from off to on. That is, the operation lever 40 is configured to pivot the pivoting shaft 20 to turn on and off the contact mechanism.
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At a substantially center of the first cam 61, a substantially circular through-hole 612 is provided. On the inner circumferential surface of the through-hole 612, a locking protrusion 613 that locks with the locking surface 23 of the pivoting shaft 20 is provided. With the locking protrusion 613, when the operation lever 40 pivots in a second direction B from the return position P1 toward the first motion position P2, the first cam 61 pivots together with the pivoting shaft 20, while when the operation lever 40 is pivoted in a first direction A from the return position P1 toward the second motion position P3, the first cam 61 does not pivot together with the pivoting shaft 20 and permits the pivoting of the pivoting shaft 20 with respect to the first cam 61.
A first contact surface 614 is provided at the end of the first transmitter 611 on the downstream side in the second direction B where the operation lever 40 moves from the return position P1 toward the first motion position P2. As illustrated in
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At a substantially center of the second cam 62, a substantially circular through-hole 622 is provided. On the inner circumferential surface of the through-hole 622, a locking protrusion 623 that locks with the locking surface 23 of the pivoting shaft 20 is provided. With the locking protrusion 623, when the operation lever 40 pivots in the first direction A from the return position P1 toward the second motion position P3, the second cam 62 pivots together with the pivoting shaft 20, while when the operation lever 40 is pivoted in the second direction B from the return position P1 toward the first motion position P2, the second cam 62 does not pivot together with the pivoting shaft 20 and permits the pivoting of the pivoting shaft 20 with respect to the second cam 62.
A second contact surface 624 is provided at the end of the second transmitter 621 on the downstream side in the first direction A where the operation lever 40 moves from the return position P1 to the second motion position P3. As illustrated in
In the limit switch 1, the first contact surface 614 of the first cam 61 and the second contact surface 624 of the second cam 62 are each disposed on the same virtual plane orthogonal to the extending direction of the pivoting shaft 20.
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The operation unit 3 includes a first cam's pivoting restriction part and a second cam's pivoting restriction part each provided inside the housing body 11.
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Note that each of the first contact surface 614 and the second contact surface 624 are formed by, for example, crushing the end of the first transmitter 611 on the downstream side in the first direction and the end of the second transmitter 621 on the downstream side in the second direction.
In the limit switch 1, the operation unit 3 includes the pivoting shaft support 50 that permits the pivoting of the pivoting shaft 20 with respect to the housing body 11 in a state of an external force along the extending direction of the pivoting shaft 20 being not applied to the operation lever 40, and contacts the peripheral wall 12 to support the pivoting shaft 20 in a state of the external force along the extending direction of the pivoting shaft 20 being applied to the operation lever 40. The pivoting shaft support 50 can prevent the deformation of the pivoting shaft 20 due to an external force along the extending direction of the pivoting shaft 20, so that it is possible to achieve the limit switch 1 that is less likely to break down.
The pivoting shaft support 50 includes the annular second bearing 51 disposed over the circumference of the pivoting shaft 20. This makes it possible to prevent the deformation of the pivoting shaft 20 at an arbitrary position around the pivoting shaft 20 due to an external force along the extending direction of the pivoting shaft 20.
In the limit switch 1, the operation unit 3 includes the operation unit detachably connected to the switch body 2, and in the operation unit 3, the pivoting shaft 20 includes the protrusion 21 that extends in the radial direction with respect to the pivoting shaft 20, and the bearing 30 includes the pivoting restriction part 31 that is disposed around the pivoting shaft 20 so as to be able to contact the protrusion 21, and restricts the pivoting of the protrusion 21 around the pivoting shaft 20. That is, the limit switch 1 restricts the pivoting of the pivoting shaft 20 not on the inside of the switch body 2 or the operation unit 3 but at the pivoting shaft 20 and the bearing 30, thereby restricting the pivoting of the operation lever 40. Thereby, even when an external force of a magnitude larger than expected is applied to the operation lever 40 from the pivoting direction thereof, it is possible to prevent the breakage of the drive component that turns on and off the contact mechanism, such as the cams 61, 62, and hence the limit switch 1 can be repaired simply by replacing the operation unit, for example. That is, it is possible to achieve the limit switch 1 that is easy to repair and has high convenience.
The operation unit 3 includes the cylindrical peripheral wall 12 surrounding the bearing 30 around the pivoting shaft 20 outside the housing body 11, and the sealer 13 that is disposed further away from the inside of the housing body 11 than the bearing 30 within the peripheral wall 12 and in the extending direction of the pivoting shaft 20 and seals the inside of the housing body 11. The protrusion 21 is disposed closer to the inside of the housing body 11 than the sealer 13 in the extending direction of the pivoting shaft 20. Hence it is possible to prevent the breakage of the drive component that turns on and off the contact mechanism units, such as the cams 61, 62 while sealing the inside of the operation unit 3, so that the convenience of the limit switch 1 can be further improved.
The pivoting shaft 20 is provided with the protrusion 21 extending outward in the radial direction from the pivoting shaft 20, and the bearing 30 is provided with the pivoting restriction part 31. This makes it possible to easily achieve the limit switch 1 easy to repair and having high convenience.
The protrusion 21 is configured by a separate member from that of the pivoting shaft 20, and the pivoting shaft 20 has the recess 22 extending in a direction intersecting with the extending direction of the pivoting shaft 20 to house and hold the protrusion 21. Thus, for example, by using a material with a higher degree of hardness than the pivoting shaft 20 to constitute the protrusion 21, the strength of the protrusion 21 can be increased.
In the limit switch 1, the operation unit 3 includes: the elastic part 63 that energizes the operation lever 40 from the first motion position P2 toward the return position P1 via the pivoting shaft 20 and the first cam 61 and energizes the operation lever 40 from the second motion position P3 to the return position P1 via the pivoting shaft 20 and the second cam 62; the first cam's pivoting restriction part 614, 71 that restricts the pivoting of the first cam 61 in the first direction A in which the operation lever 40 moves from the return position P1 to the second motion position P3; and the second cam's pivoting restriction part 624, 72 that restricts the pivoting of the second cam in the second direction B in which the operation lever 40 moves from the return position P1 to the first motion position P2. The elastic part 63, the first cam's pivoting restriction part 614, 71 and the second cam's pivoting restriction part 624, 72 can reduce the swing of the operation lever 40 at the return position P1 to immediately stop the operation lever 40 at the return position P1. As a result, it is possible to achieve the limit switch 1 that can reduce the variation of the return position P1 of the operation lever 40 and operate accurately.
Further, the first cam's pivoting restriction part includes a first contact surface 614 provided at the end of the first transmitter 611 on the downstream side in the second direction B in which the operation lever 40 moves from the return position P1 toward the first motion position P2, and the first contact protrusion 71 that is connected to the housing body 11, and contacts the first contact surface 614 when the operation lever 40 is at the return position P1, to restrict the pivoting of the first cam 61 in the first direction A. The second cam's pivoting restriction part includes a second contact surface 624 provided at the end of the second transmitter 621 on the downstream side in the first direction A, and the second contact protrusion 72 that is connected to the housing body 11, and contacts the second contact surface 624 when the operation lever 40 is at the return position P1, to restrict the pivoting of the second cam 62 in the second direction B. This makes it possible to further reduce the swing of the operation lever 40 at the return position P1.
Note that the limit switch 1 is not limited to the above embodiment, but any configuration can be employed so long as the operation unit 3 includes the pivoting shaft support 50. For example, the protrusion 21 of the pivoting shaft 20, the pivoting restriction part 31 of the bearing 30, the first cam's pivoting restriction part, and the second cam's pivoting restriction part may be omitted. Further, the operation unit 3 may be irremovably connected to the switch body 2.
The pivoting shaft support 50 is not limited to being configured by the substantially annular second bearing 51 disposed over the circumference of the pivoting shaft 20. For example, as illustrated in
The protrusion is not limited to the pivoting shaft 20, but for example, as illustrated in
The protrusion 21 is not limited to being configured by a separate member from that of the pivoting shaft 20 but may be integrally configured by the same member as that of the pivoting shaft 20.
The first cam's pivoting restriction part and the second cam's pivoting restriction part are respectively not limited to being configured by the contact surfaces 614, 624 and the contact protrusions 71, 72. For example, as illustrated in
For example, each of the first contact protrusion 71 and the second contact protrusion 72 may be configured by the same member as that of the housing body 11 or may be configured by a separate member (e.g., an elastic member such as rubber, a set screw, or a shim) from that of the housing body 11.
As described above, any configuration can be employed in each of the first cam's pivoting restriction part and the second cam's pivoting restriction part so long as being a configuration where the pivoting of the first cam 61 in the second direction B or the pivoting of the second cam 62 in the first direction A can be restricted. That is, it is possible to achieve the limit switch 1 that can accurately be operated and has high flexibility in design.
The peripheral wall 12 is not limited to being provided integrally with the housing 10 but may be provided separately. In this case, the peripheral wall 12 may be made of the same material as the housing body 11 or may be made of a different material therefrom.
In the above, various embodiments of the present disclosure have been described in detail with reference to the drawings. Finally, various aspects of the present disclosure will be described. In the following description, reference numerals will be added as examples.
A limit switch 1 according to the first aspect of the present disclosure is provided with:
a switch body 2 having a contact mechanism inside; and
an operation unit 3 connected to the switch body 2.
The operation unit 3 includes
a housing body 11 connected to the switch body 2,
a pivoting shaft 20 extending from an outside of the housing body 11 to an inside of the housing body 11 and pivotable around an extending direction of the pivoting shaft 20,
a bearing 30 that is provided in the housing body 11 and pivotably supports the pivoting shaft 20, and
an operation lever 40 that extends in a direction intersecting with the pivoting shaft 20, is connected to the pivoting shaft 20 outside the housing body 11, and pivots the pivoting shaft 20 to turn on and off the contact mechanism.
The operation unit 3 includes
a cylindrical peripheral wall 12 surrounding the bearing 30 around the pivoting shaft 20 outside the housing body 11, and
a pivoting shaft support 50 that is provided in the extending direction of the pivoting shaft 20 within the peripheral wall 12 at a position further away from the inside of the housing body 11 than the bearing 30 around the pivoting shaft 20, permits pivoting of the pivoting shaft 20 with respect to the housing body 11 in a state of an external force along the extending direction of the pivoting shaft 20 being not applied to the operation lever 40, and contacts the peripheral wall 12 to support the pivoting shaft 20 in a state of the external force along the extending direction of the pivoting shaft 20 being applied to the operation lever 40.
According to the limit switch 1 of the first aspect, the pivoting shaft support 50 can prevent the deformation of the pivoting shaft 20 due to an external force along the extending direction of the pivoting shaft 20, so that it is possible to achieve the limit switch 1 that is less likely to break down.
In the limit switch 1 according to the second aspect of the present disclosure,
the pivoting shaft support 50 includes a second bearing 51 disposed around the pivoting shaft 20, and
in a state where an external force along the extending direction of the pivoting shaft 20 is applied to the operation lever 40, an end 52 of the second bearing 51 on an outer side in a radial direction with respect to the pivoting shaft 20 contacts the peripheral wall 12 to support the pivoting shaft 20.
According to the limit switch 1 of the second aspect, it is possible to achieve the limit switch 1 that is less likely to break down and has high flexibility in design.
In the limit switch 1 according to the third aspect of the present disclosure,
the pivoting shaft support 50 includes a projection 53 extending from the pivoting shaft 20 to an outside in a radial direction with respect to the pivoting shaft 20, and
in a state where an external force along the extending direction of the pivoting shaft 20 is applied to the operation lever 40, an end of the projection 53 in a protruding direction contacts the peripheral wall 12 to support the pivoting shaft 20.
According to the limit switch 1 of the third aspect, it is possible to achieve the limit switch 1 that is less likely to break down and has high flexibility in design.
In the limit switch 1 according to the fourth aspect of the present disclosure,
the operation unit 3 includes a plurality of the pivoting shaft supports 50 arranged at intervals around the pivoting shaft 20.
According to the limit switch 1 of the fourth aspect, it is possible to achieve the limit switch 1 that is less likely to break down and has high flexibility in design.
In the limit switch 1 according to the fifth aspect of the present disclosure, the pivoting shaft support 50 is disposed over the circumference of the pivoting shaft 20.
According to the limit switch 1 of the fifth aspect, it is possible to prevent the deformation of the pivoting shaft 20 at an arbitrary position around the pivoting shaft 20 due to an external force along the extending direction of the pivoting shaft 20.
By appropriately combining any of the various embodiments or modifications described above, the effects of the respective embodiments or modifications can be achieved. In addition, a combination of embodiments, a combination of examples, or a combination of an embodiment and an example is possible, and a combination of features in different embodiments or examples is also possible.
Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. It is to be understood that, so long as not departing from the scope of the present disclosure as set forth in the appended claims, the variations and modifications as thus described are included therein.
The limit switch of the present disclosure can be applied to, for example, an assembly line of an automobile or the like.
Number | Date | Country | Kind |
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2018-047108 | Mar 2018 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/008774 | 3/3/2019 | WO | 00 |