JP2013168416A - Programmable logic controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PLC of which the replacement work of cables is easy and the workability is high even when a plurality of machines are used in parallel.SOLUTION: A plate member 12 which closes the end of a casing 11 can be pulled out from the casing 11. In addition, the pulled out plate member 12 can close the end of the casing 11 by being pushed into the side of the casing 11. Thus, when a cable 17 which is connected with a connector 16 is replaced, interference between the cable 17 pulled out with the plate member 12 and a cable 17 of an adjacent PLC 10 is reduced by pulling out the plate member 12 from the casing 11.

Description

  The present invention relates to a programmable logic controller (hereinafter abbreviated as “PLC”).

  The PLC used for equipment control accommodates a substrate in a box-shaped casing. The casing that houses the substrate is closed at the end by a plate-like plate member. The plate member is provided with a connector that is electrically connected to the substrate. The connector is exposed to the outside from the plate member, and a cable for connecting to an external device is fixed.

  Such a PLC is rarely used as a single machine, and a plurality of machines are used in parallel. Many cables are fixed to a plurality of parallel PLCs. Therefore, when exchanging some PLC cables among a plurality of PLCs, the cables fixed to the adjacent PLCs obstruct the exchange. As a result, conventionally, it is necessary to remove the PLC that is the object of cable replacement from the plurality of PLCs and replace the cable. Accordingly, there is a problem that work at the time of cable replacement becomes complicated and workability is lowered.

JP 2000-236143 A

  Therefore, an object of the present invention is to provide a PLC that is easy to replace a cable and has high workability even when a plurality of machines are used in parallel.

  In the first aspect of the present invention, the plate member that closes the end of the casing has a connector to which an external cable is attached. The plate member has a bar member extending toward the inside of the casing. The bar member is movably accommodated by a guide member provided in the casing. Thereby, the plate member can be pulled out from the casing. Moreover, the edge part of a casing can be closed by pushing in the drawn-out board member to the casing side. Thus, the plate member can be pulled out of the casing by the bar member accommodated in the guide member. Therefore, when exchanging the cable connected to the connector, the cable pulled out together with the plate member is less likely to interfere with the cable of the adjacent device by pulling out the plate member from the casing. Therefore, even when a plurality of machines are used in parallel, the cable replacement work can be facilitated and workability can be improved.

  By the way, the exchange frequency of the cable attached to PLC is only about several times in the lifetime of PLC about 10 years, for example. Therefore, the bar member extending from the plate member and the casing are in contact with each other for a long time in a fixed posture. As a result, even if the plate member is provided so as to be able to be pulled out from the casing, the rod member and the guide member are fixed, and it may be difficult to pull out the plate member. In particular, a cable connected to an external device has a large weight, and it is easy to apply a force biased downward in the direction of gravity to a movable plate member. For this reason, the bar member integral with the plate member is inclined inside the guide member, and the bar member and the guide member are in local contact with each other, and are more likely to be fixed.

  Therefore, the invention according to claim 2 further includes a support member. The support member supports the guide member so as to be rotatable with respect to the casing. As a result, when a biased force is applied to the plate member from the cable, the guide member turns with respect to the casing together with the bar member by the support member even if the bar member is inclined together with the plate member. Therefore, the guide member maintains a state substantially parallel to the bar member. As a result, local contact between the guide member and the bar member is alleviated. Therefore, even when the replacement frequency of the cable is low, the sticking between the bar member and the guide member can be reduced.

Sectional drawing in the II line | wire of FIG. Schematic perspective view showing a plurality of parallel PLCs The schematic diagram which shows the rear end of PLC by one Embodiment Schematic which shows the modification of the guide member in PLC by one Embodiment. Schematic which shows the modification of the guide member in PLC by one Embodiment. Schematic which shows the modification of the guide member in PLC by one Embodiment. The figure equivalent to FIG. 1 which shows the state which pulled out the plate member The figure equivalent to FIG. 1 which shows the modification of one Embodiment FIG. 2 is a view corresponding to FIG. 1 showing a PLC according to an embodiment, and is a schematic view showing a state in which a guide member is turned following a bar member; The figure equivalent to FIG. 1 which shows the modification of one Embodiment

Hereinafter, the PLC according to the present embodiment will be described with reference to the drawings.
As shown in FIG. 2, the plurality of PLCs 10 are used in parallel. That is, the PLC 10 is used by arranging a plurality of machines. The PLC 10 includes a casing 11, a plate member 12, a rod member 13, and a guide member 14 as shown in FIGS. 1 and 3. The casing 11 is formed in a box shape by a metal plate or the like, for example. The casing 11 may be configured in a box shape by providing a plate-like cover on a frame-like frame, for example. As shown in FIG. 1, the casing 11 accommodates a substrate 15 inside. The substrate 15 is, for example, a printed wiring board. One end of the casing 11 is open. The plate member 12 is provided at a position that closes the opening of the casing 11. At least one plate member 12 is provided at one end of the casing 11 and closes the opening of the casing 11. In the present specification, the end of the casing 11 on the opening side is defined as the rear. The plate member 12 has a connector 16. The connector 16 is provided on the plate member 12. The connector 16 is exposed on the opposite side of the plate member 12 from the casing 11. The connector 16 is attached with a cable 17 connected to an external device as shown in FIG. The cable 17 is detachable from the connector 16. The connector 16 is connected to the substrate 15 via a flat cable 18 as shown in FIG. Thereby, the connector 16 is electrically connected to the substrate 15. Further, by connecting the cable 17 to the connector 16, the cable 17 connected to the PLC 10 is ensured electrical connection with the substrate 15.

  The bar member 13 extends from the plate member 12 toward the inside of the casing 11. That is, the bar member 13 extends from the plate member 12 provided at the rear of the casing 11 to the front of the casing 11. The end of the bar member 13 on the plate member 12 side is fixed to the plate member 12. Accordingly, the bar member 13 is provided integrally with the plate member 12 and moves integrally with the plate member 12. In the case of the present embodiment, the bar members 13 are respectively provided at both end portions in the height direction of the plate member 12. Instead of providing two rod members 13 at both ends of the plate member 12, four rod members 13 may be provided from the four corners of the plate member 12 to the inside of the casing 11. Thus, the number and position of the bar members 13 can be arbitrarily set.

  The guide member 14 is provided in the casing 11. The guide member 14 is formed in a cylindrical shape, and the rod member 13 is movably accommodated inside. Thereby, the rod member 13 that moves together with the plate member 12 is guided to the cylindrical guide member 14. In the case of this embodiment, the bar member 13 is a round bar having a substantially circular cross section. Therefore, the guide member 14 is formed in a cylindrical shape whose inner diameter is slightly larger than the outer diameter of the rod member 13. The guide member 14 is not restricted to the structure which covers the edge part on the opposite side to the plate member 12 of the bar member 13, ie, the front end side of the bar member 13, like this embodiment. That is, as shown in FIG. 4, the front end 21 of the bar member 13 may be exposed from the front end of the guide member 14. In addition, the guide member 14 is configured to have a slit 22 in the axial direction as shown in FIG. 5 instead of continuously covering the outer peripheral side of the bar member 13 in the circumferential direction, or as a shaft as shown in FIG. The structure which has the slit 22 in a perpendicular | vertical direction may be sufficient. As described above, the guide member 14 may have any shape that can guide the bar member 13. The plate member 12 is movable in the front-rear direction of the casing 11 by guiding the bar member 13 integral with the plate member 12 with the guide member 14. Specifically, the plate member 12 opens the end of the casing 11 by pulling backward together with the rod member 13 as shown in FIG. On the other hand, the plate member 12 closes the end portion of the casing 11 by being pushed forward together with the rod member 13 as shown in FIG.

  In the case of the present embodiment, the PLC 10 includes a support member 30. The support member 30 is fixed to the side wall of the casing 11. The support member 30 has a fulcrum 31, and the guide member 14 is supported by the fulcrum 31. By supporting the guide member 14 at the fulcrum 31 in this way, the guide member 14 can turn with respect to the casing 11 around the fulcrum 31.

Next, the operation of the PLC 10 having the above configuration will be described.
In the case of the present embodiment, the plate member 12 covering the rear end of the PLC 10 is movable in the front-rear direction of the casing 11. Therefore, when the cable 17 is replaced or the connection destination of the cable 17 is changed to another connector 16, the connector 16 is pulled out from the casing 11 together with the plate member 12 as shown in FIG. As a result, when a plurality of PLCs are arranged in parallel as shown in FIG. 2, the plate member 12 provided with the connector 16 to be replaced or changed is more than the rear end of the other PLC 10 in parallel. Located behind. As a result, the interference between the cable 17 that changes or changes the connection destination is reduced with the cable 17 attached to the connector 16 of the adjacent PLC 10.

  By the way, since the cable 17 connected to the connector 16 is connected to an external device, the total length is long and the weight is relatively large. Therefore, a force downward from the cable 17 is applied to the plate member 12 on which the connector 16 is provided. As a result, when the plate member 12 is pulled by the cable 17, the plate member 12 tends to fall backward with the lower end as a fulcrum, and the bar member 13 integrated with the plate member 12 is also inclined inside the guide member 14. More specifically, if the guide member 14 is fixed to the casing 11, the plate member 12 tends to fall backward with the lower end 41 as the center due to the weight of the cable 17 as shown in FIG. 8. At this time, the bar member 13 integrated with the plate member 12 is inclined inside the guide member 14 and easily comes into local contact with the guide member 14 at the front end and the rear end. The PLC 10 is continuously used for a long time when installed in the facility. Therefore, the replacement of the cable 17 and the change of the connection destination are performed only about several times during the life of the PLC 10. As a result, if the rod member 13 and the guide member 14 are in local contact, the contact state for a long period is maintained. As a result, the bar member 13 is likely to stick to the guide member 14.

  Therefore, in the present embodiment, the guide member 14 that guides the bar member 13 is provided so as to be rotatable with respect to the casing 11 by the support member 30 as shown in FIG. Therefore, even if a force is applied to the plate member 12 from the cable 17 and the plate member 12 falls backward with the lower end 41 as the center, even if the bar member 13 integrated with the plate member 12 is inclined, the guide member 14 is It turns following the inclination of the bar member 13. That is, the guide member 14 follows the movement of the bar member 13 by turning around the fulcrum 31 as shown in FIG. As a result, the bar member 13 and the guide member 14 are maintained in a substantially parallel state, and local contact is avoided. As a result, even if the posture of the plate member 12 is constant for a long time without exchanging the cable 17 or changing the connection destination, the bar member 13 and the guide member 14 are close to surface contact, and the bar member 13 and the guide Adhesion with the member 14 is reduced.

  In the embodiment described above, the plate member 12 can be pulled out from the casing 11. Further, the drawn plate member 12 can close the end portion of the casing 11 by being pushed into the casing 11 side. Therefore, when exchanging the cable 17 connected to the connector 16, the cable 17 drawn out together with the plate member 12 is less likely to interfere with the cable 17 of the adjacent PLC 10 by pulling out the plate member 12 from the casing 11. Accordingly, even when a plurality of PLCs 10 are used in parallel, the cable 17 can be easily replaced and workability can be improved.

  Moreover, in one Embodiment, the supporting member 30 is supporting the guide member 14 with respect to the casing 11 so that turning is possible. As a result, when a biased force is applied from the cable 17 to the plate member 12, the guide member 14 rotates with respect to the casing 11 together with the bar member 13 by the support member 30 even if the bar member 13 is inclined together with the plate member 12. . Therefore, the guide member 14 maintains a state substantially parallel to the bar member 13. As a result, local contact between the bar member 13 and the guide member 14 is alleviated. Therefore, even when the replacement frequency of the cable 17 is low, the sticking between the bar member 13 and the guide member 14 can be reduced.

  The present invention described above is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof. For example, in one embodiment, the guide member 14 has been described as being supported by the support member 30 so as to be pivotable. However, if there is little risk of sticking between the bar member 13 and the guide member 14, the support member 30 may not be used as shown in FIG. That is, when the risk of sticking between the bar member 13 and the guide member 14 is small, the guide member 14 does not need to follow the bar member 13 and turn with respect to the casing 11. Therefore, the guide member 14 may be directly fixed to the casing 11 without using the support member 30. Thereby, the structure can be further simplified.

  Moreover, in one Embodiment, the support member 30 demonstrated the example which supports the guide member 14 in the approximate center in the axial direction. However, the support member 30 may be configured to support the guide member 14 at a position biased forward or backward in the axial direction. For example, equipment such as a factory in which the PLC 10 is installed is relatively likely to vibrate due to general work. Therefore, the vibration generated in the facility is naturally transmitted to the casing 11 of the PLC 10. When the casing 11 vibrates, a relative positional deviation also occurs between the guide member 14 supported by the casing 11 via the support member 30 and the bar member 13 fixed to the plate member 12. . For this reason, by utilizing the vibration of the casing 11, the rod member 13 and the guide member 14 are displaced relative to each other, and a reduction in fixation is expected. Therefore, the support member 30 may be disposed closer to the plate member 12 than the center in the axial direction of the guide member 14 as shown in FIG. Thereby, the guide member 14 tends to increase the amount of movement at the front end side, that is, the end opposite to the plate member 12 with the support member 30 as a fulcrum, and the vibration tends to increase. As a result, the relative positional deviation between the bar member 13 and the guide member 14 becomes large, and sticking is also reduced. Therefore, when the PLC 10 is installed in a facility with vibrations such as a factory, the sticking between the bar member 13 and the guide member 14 can be more reliably reduced using the vibration.

  In the drawings, 10 is a PLC (programmable logic controller), 11 is a casing, 12 is a plate member, 13 is a bar member, 14 is a guide member, 15 is a substrate, 16 is a connector, 17 is a cable, and 30 is a support member.

Claims (2)

A casing for accommodating the substrate inside,
A plate member that is electrically connected to the substrate and to which an external cable is attached, can be pulled out from the end of the casing, and closes the end of the casing;
A bar member extending from the plate member toward the inside of the casing and provided integrally with the plate member;
A guide member that is provided in the casing, movably accommodates the rod member inside, and guides the movement of the rod member integral with the plate member;
A programmable logic controller comprising:   The programmable logic controller according to claim 1, further comprising a support member that supports the guide member so as to be rotatable with respect to the casing.

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