Programmable logic controller and its base unit and module unit

Abstract

A programmable logic controller capable of achieving durable waterproof or dustproof properties is provided. A base unit (1) comprises a substrate (10), a base housing (12) for accommodating the substrate (10), and a holding portion (14) for holding one of a plurality of module units, namely a connection unit (2a). The connection unit (2a) comprises a module-side connector (20), a snap-fit ​​portion (21) that can be freely and detachably snap-fitted with the holding portion (14), and a module housing (22) that comprises a snap-fit ​​portion that is snap-fitted with the base housing (12). Furthermore, the programmable logic controller comprises: an elastic component (31) that applies a force in a first direction, namely a direction in which the connection unit (2a) moves away from the base unit (1), to press the snap-fit ​​portion of the connection unit (2a) against the holding portion (14) of the base unit (1); and a sealing material (30) that seals the gap between the snap-fit ​​portions of the base housing (12) and the module housing (22).

Description

Technical Field

[0001] The invention relates to a programmable logic controller and a base unit and a module unit thereof. Background Art

[0002] A conventional programmable logic controller (hereinafter referred to as a "PLC") is composed of a base unit and a module unit connected to the base unit. A network interface, which is a type of module unit, is connected to a standard input / output module unit via a network cable. A pad having elastic force is installed around a connector of the standard input / output module unit, and a pad is also installed around a connector of a safety circuit unit connected to the connector (for example, refer to Patent Document 1).

[0003] Patent Document 1: Japanese Patent No. 6865912 Summary of the invention

[0004] For example, sometimes, after hooking one end of the module unit to the base unit, the other end of the module unit is inserted into the base unit side, so that the module unit is engaged with the base unit and the module unit is held by the base unit. In this case, the base unit and the module unit are not fixed by screws or the like, so the module unit is easily shaken due to an impact applied from the outside.

[0005] In the above-mentioned PLC, in order to protect the substrate of the base unit from damage by surrounding water or dust, the substrate is housed in the base housing, and a sealing material such as a gasket is provided between the base housing and the module unit. Sometimes, the sealing material is twisted or worn due to the shaking of the module unit caused by an external impact. Therefore, there is a problem that the sealing material is easily damaged, and the waterproof or dustproof properties based on the sealing material are not durable.

[0006] The present invention is proposed to solve the above-mentioned problems, and an object of the present invention is to obtain a PLC, a base unit of the PLC, and a module unit of the PLC that can make the waterproofness or dustproofness based on the sealing material lasting.

[0007] The PLC of the present invention is a programmable logic controller having a base unit and a plurality of module units connected to the base unit. In the programmable logic controller, the base unit has: a substrate having a plurality of base-side connectors, the substrate electrically connecting the plurality of module units via the plurality of base-side connectors; a base shell having an opening for exposing one of the plurality of base-side connectors, the base shell accommodating the substrate; and a holding portion for holding one of the plurality of module units, namely a connection unit, the connection unit having: a module-side connector connected to one of the plurality of base-side connectors; a snap-fit ​​portion for engaging with the holding portion of the base unit The part can be freely and detachably engaged; and a module shell, which has an engaging portion engaged with the base shell, and the engaging portion is arranged in a manner to surround the module-side connector. The programmable logic controller comprises: an elastic component, which applies a force in the direction in which the connecting unit moves away from the base unit, that is, in the first direction, to press the engaging portion of the connecting unit against the retaining portion of the base unit; and a sealing material, which seals the gap between the engaging portion of the base shell and the module shell, and a plurality of retaining portions are provided to form a pair, and the pair of retaining portions have an inclined surface inclined relative to the first direction to apply the force generated by the elastic component to a second direction intersecting the first direction.

[0008] The base unit involved in the present invention comprises: a substrate having a plurality of base-side connectors, and the substrate electrically connects a plurality of module units via the plurality of base-side connectors; a base shell having an opening for exposing the plurality of base-side connectors, and the base shell accommodates the substrate; a holding portion, which engages with an engaging portion of one of the plurality of module units, namely, a connecting unit, to hold the module unit; an elastic component, which applies a force in a direction in which the connecting unit moves away from the base unit, namely, in a first direction, to press the engaging portion of the connecting unit against the holding portion of the base unit; and a sealing material, which seals a gap between an engaging portion of the module shell of the connecting unit and the base shell, the engaging portion being arranged to surround the module-side connector of the connecting unit connected to one of the plurality of base-side connectors, and the engaging portion being engaged with the base shell, a plurality of holding portions being arranged to form a pair, and the pair of holding portions having an inclined surface inclined relative to the first direction to apply a force generated by the elastic component to a second direction intersecting the first direction.

[0009] The module unit involved in the present invention comprises: a module-side connector, which is connected to one of the base-side connectors of the base unit; a snap-fitting portion, which is snap-fitted with the retaining portion of the base unit in a freely detachable manner; a module shell, which has a snap-fitting portion that is snap-fitted with the base shell of the base unit, and the snap-fitting portion is arranged in a manner to surround the module-side connector; an elastic component, which applies a force in a direction in which the module unit moves away from the base unit, i.e., in a first direction, to press the snap-fitting portion of the module unit against the retaining portion of the base unit; and a sealing material, which seals a gap between the retaining portion of the base shell and the module shell, a plurality of retaining portions are provided to form a pair, and the pair of retaining portions have an inclined surface inclined relative to the first direction to apply the force generated by the elastic component to a second direction intersecting the first direction.

[0010] Effects of the Invention

[0011] According to the present invention, a PLC, a base unit of the PLC, and a module unit of the PLC can be obtained, which can make the waterproofness or dustproofness by the sealing material last forever. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a perspective view of the PLC in Implementation Example 1.

[0013] Figure 2 This is a perspective view of the base unit in Embodiment 1.

[0014] Figure 3 This is a BB' cross-sectional view of the base unit in the first embodiment.

[0015] Figure 4 This is a perspective view of the second holding portion in the first embodiment.

[0016] Figure 5 This is a perspective view of the connection unit in the first embodiment.

[0017] Figure 6 This is a perspective view of the second engaging portion in the first embodiment.

[0018] Figure 7 This is a cross-sectional view taken along the line AA′ of the PLC in the first embodiment.

[0019] Figure 8 This is a cross-sectional view taken along the line CC' of the PLC in the first embodiment.

[0020] Fig. 9 This is a DD' cross-sectional view of the PLC in the first embodiment.

[0021] Fig.10 This is a top view of the PLC in the first embodiment.

[0022] Fig.11A modification of the first embodiment is shown, and is a cross-sectional view taken along the line AA' of the PLC.

[0023] Fig.12 A modification of the first embodiment is shown, and is a front view of the base unit.

[0024] Fig.13 This is a cross-sectional view taken along the line AA′ of the PLC in the second embodiment.

[0025] Fig.14 A modification of the second embodiment is shown, and is a cross-sectional view taken along the line AA' of the PLC.

[0026] Fig.15 This is a perspective view of the base unit in the third embodiment.

[0027] Fig.16 This is a perspective view of the connection unit in the third embodiment.

[0028] Fig.17 This is a top view of the PLC in the third embodiment.

[0029] Fig.18 This is a top view of the PLC in the third embodiment.

[0030] Fig.19 This is a perspective view of the base unit in the fourth embodiment.

[0031] Fig. 20 This is a perspective view of the connection unit in the fourth embodiment.

[0032] Fig.21 This is a top view of the PLC in the fourth embodiment. DETAILED DESCRIPTION

[0033] Implementation Method 1

[0034] The PLC in the first embodiment is described. In addition, the same reference numerals in the drawings represent the same or corresponding structures. Figure 1 As shown, the PLC includes a base unit 1 and a plurality of module units 2. The plurality of module units 2 are fixed in parallel to the base unit 1. A module unit 2 connected to the base unit 1 as one of the plurality of module units 2 is referred to as a connection unit 2a.

[0035] In the following description, the direction in which the connection unit 2a is away from the base unit 1 is referred to as the longitudinal direction, and the direction parallel to the parallel direction of the plurality of module units 2 is referred to as the transverse direction. The transverse direction is a direction intersecting the longitudinal direction, and is a direction orthogonal to the longitudinal direction and the height direction described later. In addition, the side of the base unit 1 relative to the module unit 2 is referred to as the distal side, and the side of the module unit 2 relative to the base unit 1 is referred to as the proximal side. In addition, the longitudinal direction is equivalent to the first direction, and either the transverse direction or the height direction described later is equivalent to the second direction.

[0036] Figure 2 An oblique view of the base unit 1 is shown, Figure 3 The BB' cross-sectional view of the base unit 1 is shown. The base unit 1 is composed of a substrate 10 and a base housing 12 that accommodates the substrate 10. The substrate 10 has a plurality of base-side connectors 11. One of the plurality of base-side connectors 11 is connected to a module-side connector 20 of a connection unit 2a described later. Since the module-side connector 20 is connected to the base-side connector 11, the substrate 10 electrically connects the plurality of module units 2 via the plurality of base-side connectors 11.

[0037] The base housing 12 is composed of a front surface cover 12a and a rear surface cover 12b. The front surface cover 12a is, for example, a resin component or a metal component. The rear surface cover 12b is, for example, a metal component formed by stamping. The base housing 12 accommodates the substrate 10 by sandwiching the substrate 10 between the front surface cover 12a and the rear surface cover 12b. In addition, a gasket 16 is sandwiched between the front surface cover 12a and the rear surface cover 12b. The gasket 16 is set to surround the periphery of the substrate 10, so that water or dust can be prevented from entering from between the front surface cover 12a and the rear surface cover 12b, and water or dust will not reach the substrate 10.

[0038] A concave portion 18 of a rounded rectangular shape that is concave toward the far end is formed in the front cover 12a. The concave portion 18 is a portion to be engaged with an engaging portion 22a of a module housing 22 described later. The concave portion 18 has an opposing surface 18a that is opposed to a side surface 22aa of the engaging portion 22a described later. The concave portion 18 also has an opening 13 that exposes one of the plurality of base-side connectors 11 provided on the substrate 10.

[0039] The front surface cover 12a has a holding portion for holding the connection unit 2a. A plurality of holding portions are provided to form a pair. The plurality of holding portions forming a pair are referred to as a pair of holding portions 14. One holding portion of the pair of holding portions 14, namely the first holding portion 14a, is formed to extend in the longitudinal direction from one end of the front surface cover 12a. The other holding portion of the pair of holding portions 14, namely the second holding portion 14b, is formed to extend in the longitudinal direction from the other end of the front surface cover 12a. Therefore, the first holding portion 14a and the second holding portion 14b are opposite to each other across the opening 13. A direction parallel to the direction from the first holding portion 14a toward the second holding portion 14b is set as a height direction. The height direction is a direction intersecting the longitudinal direction.

[0040] The ends of both sides of the first holding portion 14a in the lateral direction and the end on the proximal side are protruded toward the second holding portion 14b. In addition, the first holding portion 14a has an inclined surface 4a inclined with respect to the longitudinal direction to apply a force generated by a leaf spring 31 described later in the lateral direction. A plurality of inclined surfaces 4a are provided in a manner to sandwich the first engaging portion 21a of the connecting unit 2a described later from both sides in the lateral direction, and the intervals between the inclined surfaces 4a are formed to gradually narrow toward the longitudinal direction.

[0041] Figure 4 FIG. 2 shows a perspective view of the second holding portion 14b viewed from the first holding portion 14a side. Figure 4 As shown, the ends of both sides of the second holding portion 14b in the lateral direction and the end on the proximal side protrude toward the first holding portion 14a. The second holding portion 14b has an inclined surface 4b inclined relative to the longitudinal direction to apply a force generated by a leaf spring 31 described later in the lateral direction. A plurality of inclined surfaces 4b are provided in a manner to sandwich the second engaging portion 21b of the connecting unit 2a described later from both sides in the lateral direction, and the intervals between the inclined surfaces 4b are formed to gradually narrow toward the longitudinal direction.

[0042] like Figure 2 As shown, the front cover 12a has a plurality of guide portions 15 formed in a manner extending in the longitudinal direction from the other end of the front cover 12a. The guide portion 15 is a hollow rectangular parallelepiped shape with both sides opened in the height direction. The plurality of guide portions 15 are arranged so that when the connection unit 2a is held in the base unit 1, at least two of the plurality of guide portions 15 are adjacent to the module housing 22 described later. In the present embodiment, when the connection unit 2a is held in the base unit 1, two guide portions 15 are arranged adjacent to the module housing 22 described later.

[0043] Figure 5 An oblique view of one of the plurality of module units 2, namely the connection unit 2a, as viewed from the far end side is shown. The connection unit 2a has a module-side connector 20 connected to one of the plurality of base-side connectors 11. In addition, the connection unit 2a has a module housing 22. The module housing 22 has a rounded rectangular fitting portion 22a that fits into the recess 18 of the front surface cover 12a of the base housing 12 and is provided in a manner to surround the module-side connector 20. The connection unit 2a has a fitting portion 21 that can be freely and detachably engaged with a pair of retaining portions 14 of the base unit 1. The fitting portion 21 is composed of a first fitting portion 21a and a second fitting portion 21b. The fitting portions 21 are respectively provided at the ends in the height direction of the module housing 22 in such a manner that the first fitting portion 21a is engaged with the first retaining portion 14a, and the second fitting portion 21b is engaged with the second retaining portion 14b.

[0044] The first engagement portion 21 a has an inclined surface 5 a which will be described later. Figure 6The second engaging portion 21b is shown in a perspective view. The second engaging portion 21b has an inclined surface 5b inclined relative to the longitudinal direction to apply the force generated by the leaf spring 31 in the transverse direction. The inclined surface 5b is formed to be inclined in a manner that the width in the transverse direction gradually narrows toward the longitudinal direction. When the connecting unit 2a is held on the base unit 1, the inclined surface 5b abuts against the inclined surface 4b of the second holding portion 14b.

[0045] The second engaging portion 21b has an inclined surface 5c inclined with respect to the longitudinal direction so as to apply the force generated by the leaf spring 31 in the transverse direction. The inclined surface 5c is formed to be inclined in a manner that the width in the transverse direction gradually widens toward the longitudinal direction. The module housing 22 has a plurality of inclined surfaces 5d arranged in a manner that sandwiches the second engaging portion 21b from both sides. The inclined surfaces 5d are formed so that the intervals between the inclined surfaces 5d gradually widen toward the longitudinal direction. When the connection unit 2a is held on the base unit 1, the inclined surface 5c of the second engaging portion 21b abuts against the inclined surface 5d of the module housing 22.

[0046] like Figure 5 As shown, the module housing 22 has a recess 22b formed along the plurality of guide portions 15 of the front cover 12a on both sides of the module housing 22 in the lateral direction. The recess 22b is a shape obtained by hollowing out a rectangular parallelepiped. By forming the recess 22b as shown above, when the connection unit 2a is held in the base unit 1, a part of the module housing 22 is arranged between the second holding portion 14b and the guide portion 15 of the base unit 1.

[0047] A gasket 30 is provided on the side surface 22aa parallel to the longitudinal direction of the fitting portion 22a of the module case 22 to seal the gap between the base case 12 and the fitting portion 22a of the module case 22. A leaf spring 31 is provided on the surface of the module case 22 facing the base unit 1 as an elastic member.

[0048] Next, a mechanism for reducing the load on the pad 30 in the PLC configured as described above will be described.

[0049] Figure 7 The A-A' cross-sectional view of the PLC is shown in a state where the connection unit 2a is held in the base unit 1. The connection unit 2a is held in the base unit 1 by engaging the first engaging portion 21a of the connection unit 2a with the first holding portion 14a of the base unit 1 and engaging the second engaging portion 21b of the connection unit 2a with the second holding portion 14b of the base unit 1. At this time, the base-side connector 11 is connected to the module-side connector 20. In addition, since the leaf spring 31 abuts against the rear surface cover 12b and applies a force in the longitudinal direction, the engaging portion 21 of the connection unit 2a is pressed against the pair of holding portions 14 of the base unit 1.

[0050] Even if an external force is applied in a direction from the connection unit 2a to the base unit 1, that is, even if an external force is applied in a direction opposite to the longitudinal direction, the external force can be suppressed because the force is applied longitudinally by the leaf spring 31. Therefore, the shaking of the connection unit 2a can be suppressed, and the load on the pad 30 can be reduced.

[0051] Figure 8 The CC' cross-sectional view of the enlarged engagement portion of the first holding portion 14a and the first engaging portion 21a is shown. The first holding portion 14a has an inclined surface 4a inclined in a manner that the width in the lateral direction gradually narrows toward the longitudinal direction. The first engaging portion 21a has an inclined surface 5a inclined relative to the longitudinal direction to apply the force generated by the leaf spring 31 in the lateral direction. The inclined surface 5a is inclined in a manner that the width in the lateral direction gradually narrows toward the longitudinal direction.

[0052] When the connection unit 2a is held on the base unit 1, the inclined surface 4a of the first holding portion 14a contacts the inclined surface 5a of the first engaging portion 21a. The inclined surface 5a is pressed against the inclined surface 4a by the longitudinal force of the leaf spring 31, so that the force generated by the leaf spring 31 is converted into a lateral force. Therefore, even if an external force is applied from the lateral direction, the external force is suppressed by the lateral force converted by the inclined surface 4a or the inclined surface 5a. By this suppression, the shaking of the connection unit 2a is suppressed, so that the load on the pad 30 can be reduced.

[0053] Fig. 9 FIG. 2 shows a cross-sectional view of the DD' enlarged engagement portion between the second retaining portion 14b and the second engagement portion 21b. Fig. 9 As shown in FIG. 1 , when the connection unit 2a is held on the base unit 1, the inclined surface 4b of the second holding portion 14b contacts the inclined surface 5b of the second engaging portion 21b. The inclined surface 5b is pressed against the inclined surface 4b by the longitudinal force of the leaf spring 31, so that the force generated by the leaf spring 31 is converted into a lateral force. Therefore, even if an external force is applied from the lateral direction, the external force is suppressed by the lateral force converted from the inclined surface 4b or the inclined surface 5b, and the load on the pad 30 can be reduced.

[0054] When the connection unit 2a is held on the base unit 1, the second engaging portion 21b engages with the second holding portion 14b, so that the width between the inclined surface 5c of the second engaging portion 21b and the inclined surface 5d of the module housing 22 is narrow, and the inclined surface 5c abuts against the inclined surface 5d. At this time, the inclined surface 5c is pressed against the inclined surface 5d. The pressing force is converted into a lateral force by the inclined surface 5c or the inclined surface 5d. Therefore, even if an external force is applied from the lateral direction, the external force is suppressed by the lateral force converted from the inclined surface 5c or the inclined surface 5d, thereby suppressing the shaking of the connection unit 2a, thereby reducing the load on the pad 30.

[0055] Fig.10 The diagram shows an enlarged top view of the adjacent parts of the guide portion 15 and the module housing 22 when an external force is applied from the lateral direction. If an external force is applied from the lateral direction, a portion of the module housing 22 sandwiched between the second retaining portion 14b and the guide portion 15 comes into contact with the second retaining portion 14b and the guide portion 15. By making a portion of the module housing 22 come into contact with the second retaining portion 14b and the guide portion 15 as shown above, further lateral movement of the connection unit 2a is restricted. That is, the shaking of the connection unit 2a can be suppressed. Therefore, the load on the gasket 30 can be reduced.

[0056] In a PLC having a plate spring 31 that applies force in the longitudinal direction to press the engaging portion 21 of the connection unit 2a against the pair of holding portions 14 of the base unit 1 as described above, and a gasket 30 that seals the gap between the base housing 12 and the fitting portion 22a of the module housing 22, even if an external force is applied in a direction opposite to the longitudinal direction, the force is applied in the longitudinal direction by the plate spring 31, so that the external force can be suppressed. Therefore, the shaking of the connection unit 2a can be suppressed, and the load on the gasket 30 can be reduced. Therefore, the gasket 30 becomes less likely to be damaged by twisting or abrasion, etc., and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0057] The first holding portion 14a is engaged with the first engaging portion 21a at one end of the front cover 12a, and the second holding portion 14b is engaged with the second engaging portion 21b at the other end. Furthermore, at the other end of the front cover 12a, a portion of the module housing 22 is sandwiched between the guide portion 15 and the second holding portion 14b. As described above, the external force from the lateral direction can be suppressed at both ends in the height direction, so the load on the gasket 30 can be further reduced. Therefore, the gasket 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0058] Furthermore, in the PLC of the first embodiment, a gasket 30 is provided on the side surface 22aa of the fitting portion 22a of the module case 22 to seal the gap between the base case 12 and the fitting portion 22a of the module case 22. By providing the gasket 30 as described above, it is possible to suppress the gap from being formed between the base case 12 and the fitting portion 22a of the module case 22 due to the longitudinal force of the leaf spring 31. Therefore, the waterproofness or dustproofness of the gasket 30 can be made durable.

[0059] Furthermore, for the PLC in Embodiment 1, the inclined surfaces 4a and 4b of a pair of holding portions 14 are inclined relative to the longitudinal direction so as to apply the force generated by the leaf spring 31 in the transverse direction. That is, the inclined surface 4a of the first holding portion 14a is inclined in such a manner that the width in the transverse direction gradually narrows toward the longitudinal direction. The inclined surface 4b of the second holding portion 14b is formed so that the interval between the two inclined surfaces 4b gradually narrows toward the longitudinal direction. By forming the inclined surfaces 4a and 4b as shown above, the force applied in the longitudinal direction by the leaf spring 31 is converted into a transverse force. Therefore, even if an external force is applied in the transverse direction, the external force is suppressed by the transverse force converted from the inclined surfaces 4a and 4b. Therefore, the shaking of the connection unit 2a can be suppressed, and thus the load on the pad 30 can be reduced. Therefore, the pad 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the pad 30 can be made durable.

[0060] Furthermore, for the PLC in the first embodiment, the inclined surfaces 5a and 5b of the engaging portion 21 are inclined relative to the longitudinal direction so as to apply the force generated by the leaf spring 31 in the transverse direction. That is, the inclined surface 5a of the first engaging portion 21a is inclined in a manner that the width in the transverse direction gradually narrows toward the longitudinal direction. The inclined surface 5b of the second engaging portion 21b is formed to be inclined in a manner that the width in the transverse direction gradually narrows toward the longitudinal direction. By forming the inclined surfaces 5a and 5b as shown above, the force applied in the longitudinal direction by the leaf spring 31 is converted into a transverse force. Therefore, even if an external force is applied in the transverse direction, the external force is suppressed by the transverse force converted by the inclined surfaces 5a and 5b. Therefore, the shaking of the connection unit 2a can be suppressed, and thus the load on the pad 30 can be reduced. Therefore, the pad 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the pad 30 can be made durable.

[0061] Furthermore, for the PLC in the first embodiment, the inclined surface 5d of the module housing 22 is inclined in a manner that the width in the lateral direction gradually widens toward the longitudinal direction. When the connection unit 2a is held on the base unit 1, the second engaging portion 21b abuts against the second holding portion 14b, so that the width between the inclined surface 5c of the second engaging portion 21b and the inclined surface 5d of the module housing 22 becomes narrower, and the inclined surface 5c abuts against the inclined surface 5d. At this time, the inclined surface 5c presses on the inclined surface 5d. The pressing force is converted into a lateral force by the inclined surface 5c or the inclined surface 5d. Therefore, even if an external force is applied from the lateral direction, the external force is suppressed by the lateral force converted from the inclined surface 5c or the inclined surface 5d. Therefore, the shaking of the connection unit 2a can be suppressed, and the load on the pad 30 can be reduced. Therefore, the pad 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the pad 30 can be made durable.

[0062] Furthermore, for the PLC in Embodiment 1, the base unit 1 has a plurality of guides 15 formed to extend in the longitudinal direction, and the module housing 22 has a recess 22b formed along the plurality of guides 15, and when the connection unit 2a is held on the base unit 1, two of the plurality of guides 15 are adjacent to the module housing 22. At this time, a portion of the module housing 22 is arranged between the second holding portion 14b and the guide 15. If an external force is applied from the lateral direction, the module housing 22 contacts the second holding portion 14b and the guide 15. Therefore, it is possible to restrict the connection unit 2a from further moving in the lateral direction. That is, it is possible to suppress the shaking of the connection unit 2a, so that the load on the gasket 30 can be reduced. Therefore, the gasket 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0063] Furthermore, although an example has been described in which two of the plurality of guide portions 15 are adjacent to the module housing 22 when the connection unit 2a is held on the base unit 1, the guide portions 15 may be formed in such a manner that three or more guide portions 15 are adjacent to the module housing 22. In addition, the guide portion 15 may not be formed at the other end of the front cover 12a, but may be formed at one end of the front cover 12a or between one end and the other end of the front cover 12a.

[0064] Furthermore, the guide portion 15 may be in the shape of a rectangular parallelepiped that is not open in the height direction.

[0065] Furthermore, the pair of holding portions 14 of the base unit 1 may also be formed so as to extend from the rear surface cover 12 b .

[0066] In addition, the first holding portion 14a of the base unit 1 may be extended from the other end of the front cover 12a, and the second holding portion 14b may be extended from one end of the front cover 12a. In this case, the engaging portion 21 of the connection unit 2a is provided at the end of the height direction of the module housing 22 in such a manner that the first engaging portion 21a engages with the first holding portion 14a, and the second engaging portion 21b engages with the second holding portion 14b.

[0067] In addition, the example in which the pair of holding portions 14 of the base unit 1 are formed to extend in the longitudinal direction from the front cover 12a has been described, but it is also possible to Fig.11 As shown, the first engaging portion 21a of the connection unit 2a is formed to extend in the direction opposite to the longitudinal direction, and the second engaging portion 21b is formed to extend in the direction opposite to the longitudinal direction. At this time, the pair of holding portions 14 can be any shape as long as the engaging portion 21 can engage with the pair of holding portions 14. For example, the engaging portion 21 can be hooked to the pair of holding portions 14 so that the engaging portion 21 engages with the pair of holding portions 14. Even with the above-mentioned structure, the base unit 1 can hold the connection unit 2a.

[0068] Alternatively, the gasket 30 may be provided on the facing surface 18 a of the recess 18 of the base case 12 that faces the side surface 22 aa of the fitting portion 22 a so as to seal the gap between the base case 12 and the fitting portion 22 a of the module case 22 . Fig.12 The front view shows a state where the gasket 30 is provided on the opposing surface 18a.

[0069] In addition, the elastic member is not limited to the leaf spring 31, and any member capable of applying force longitudinally, such as a coil spring or a rubber member, may be used. In addition, the example in which the leaf spring 31 is provided in the connection unit 2a is described, but it may also be provided on the surface of the base unit 1 opposite to the module housing 22.

[0070] Even in the PLC configured as described above, even if an external force is applied in the direction opposite to the longitudinal direction, for example, the external force can be suppressed because the force is applied in the longitudinal direction by the leaf spring 31. Therefore, the shaking of the connection unit 2a can be suppressed, and the load on the gasket 30 can be reduced. Therefore, the gasket 30 becomes less likely to be damaged by twisting or abrasion, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0071] Implementation Method 2

[0072] In the first embodiment, an example is described in which a pair of holding portions 14 of the base unit 1 and the engaging portion 21 of the module unit 2 have inclined surfaces inclined relative to the longitudinal direction to apply the force generated by the leaf spring 31 in the transverse direction. In the second embodiment, an example is described in which a pair of holding portions 14 and the engaging portion 21 have inclined surfaces inclined relative to the longitudinal direction to apply the force generated by the leaf spring 31 in the height direction. Specifically, the inclination directions of the inclined surfaces of the pair of holding portions 14 and the inclined surfaces of the engaging portion 21 are different from those in the first embodiment, so the following description focuses on the differences.

[0073] Fig.13 AA' cross-sectional view of the PLC in a state where the connection unit 2a is held on the base unit 1 is shown. Fig.13 As shown, the first holding portion 14a of the base unit 1 has an inclined surface 4c inclined with respect to the longitudinal direction to apply the force generated by the leaf spring 31 in the height direction. The inclined surface 4c is inclined so as to gradually approach the second holding portion 14b side toward the longitudinal direction.

[0074] The first engagement portion 21a of the connection unit 2a has an inclined surface 5e inclined with respect to the longitudinal direction to apply the force generated by the leaf spring 31 in the height direction. The inclined surface 5e is inclined so as to gradually approach the second holding portion 14b side toward the longitudinal direction.

[0075] Next, the mechanism for reducing the load on the pad 30 in the PLC configured as described above will be described. When the connection unit 2a is held on the base unit 1, the inclined surface 4c of the first holding portion 14a contacts the inclined surface 5e of the first engaging portion 21a. The inclined surface 5e is pressed against the inclined surface 4c by the longitudinal force of the leaf spring 31, so that the force generated by the leaf spring 31 is converted into a force in the direction from the first holding portion 14a toward the second holding portion 14b in the height direction. Therefore, even if an external force is applied in the direction from the second holding portion 14b toward the first holding portion 14a, the external force is suppressed by the height direction force converted by the inclined surface 4c or the inclined surface 5e. Therefore, the shaking of the connection unit 2a can be suppressed, and the load on the pad 30 can be reduced. Therefore, the pad 30 becomes less likely to be damaged by twisting or abrasion, etc., and the waterproofness or dustproofness based on the pad 30 can be made durable.

[0076] In addition, if Fig.14 As shown, an inclined surface 4d inclined in a manner gradually approaching the first holding portion 14a side in the longitudinal direction may be formed on the second holding portion 14b of the base unit 1. In addition, an inclined surface 5f inclined in a manner gradually approaching the first holding portion 14a side in the longitudinal direction may be formed on the second engaging portion 21b of the connecting unit 2a. In the case of the inclined surface as described above, the force generated by the leaf spring 31 is converted into a force in the direction from the second holding portion 14b toward the first holding portion 14a in the height direction. Therefore, even if an external force is applied in the direction from the first holding portion 14a toward the second holding portion 14b, the external force is suppressed by the force in the height direction converted by the inclined surface 4d or the inclined surface 5f. Therefore, the shaking of the connecting unit 2a can be suppressed, and the load on the pad 30 can be reduced. Therefore, the pad 30 becomes less likely to be damaged, and the waterproofness or dustproofness based on the pad 30 can be made durable.

[0077] Implementation 3

[0078] In the first embodiment, an example of forming the guide portion 15 in a hollow rectangular parallelepiped shape extending in the longitudinal direction from the other end of the front cover 12a is described, but in the third embodiment, an example of forming the guide portion 17 in a hollow trapezoidal column shape is described. Specifically, the guide portion 17 is different from the first embodiment in that it has an inclined surface 4e inclined with respect to the longitudinal direction, so the following describes the difference.

[0079] like Fig.15 As shown, the front cover 12a has a plurality of guides 17 formed in a manner extending in the longitudinal direction from the other end of the front cover 12a. The guides 17 are in the shape of a hollow trapezoidal column with both sides open in the height direction. The plurality of guides 17 are arranged so that when the connection unit 2a is held in the base unit 1, two guides 17 are adjacent to the module housing 22.

[0080] Fig.16 The figure shows an oblique view of the connection unit 2a viewed from the far end. The module housing 22 has recessed portions 22c formed along the plurality of guide portions 17 on both sides in the lateral direction. The recessed portions 22c are shaped like a trapezoidal column. By forming the recessed portions 22c as shown above, when the connection unit 2a is held in the base unit 1, a portion of the module housing 22 is disposed between the second holding portion 14b of the base unit 1 and the guide portion 17.

[0081] Fig.17 Figure 2 shows a top view of the PLC. Fig.17 As shown, the plurality of guide portions 17 have inclined surfaces 4 e inclined so that the width in the lateral direction gradually narrows toward the longitudinal direction.

[0082] Fig.18 The diagram shows an enlarged top view of the adjacent portion between the guide portion 17 and the module housing 22 when an external force is applied from the lateral direction. If an external force is applied from the lateral direction, a portion of the module housing 22 sandwiched between the second retaining portion 14b and the guide portion 17 contacts the second retaining portion 14b and the guide portion 17. By making a portion of the module housing 22 contact the second retaining portion 14b and the guide portion 17 as shown above, further lateral movement of the connection unit 2a is restricted. That is, the shaking of the connection unit 2a can be suppressed, so the load on the gasket 30 can be reduced. Therefore, the gasket 30 becomes less likely to be damaged by twisting or abrasion, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0083] In addition, since the guide portion 17 has the inclined surface 4e, it is possible to increase the contact area between the connection unit 2a and the guide portion 17 when an external force is applied from the lateral direction so that the connection unit 2a approaches the inclined surface 4e and the connection unit 2a contacts the guide portion 17. Therefore, for example, even if an external force is applied to the module housing 22 that would not restrict the lateral movement of the connection unit 2a if the contact area between the connection unit 2a and the guide portion 17 is small, the guide portion 17 has the inclined surface 4e and the contact area is large, so that the lateral movement of the connection unit 2a can be restricted.

[0084] By setting the shape of the guide portion 17 to a hollow trapezoidal column shape, the volume reduction of the module case 22 due to the recess 22c can be suppressed compared to when the guide portion 17 is a hollow rectangular parallelepiped shape. Therefore, the volume of the module case 22 can be increased. Therefore, a plurality of electronic components built into the module case 22 can be separately arranged, and the heat dissipation of the electronic components can be improved.

[0085] In addition, the guide portion 17 may be in any shape as long as it has the inclined surface 4 e , and may be in a triangular prism shape instead of a hollow trapezoidal column shape.

[0086] In addition, the inclined surface 4e of the guide portion 17 may be inclined so that the width in the height direction gradually narrows toward the longitudinal direction. Even with the guide portion 17 as described above, the volume reduction of the module housing 22 due to the recess 22c can be suppressed compared to when the guide portion 17 is a hollow rectangular parallelepiped. Therefore, the volume of the module housing 22 can be increased.

[0087] Implementation 4

[0088] In the first embodiment, an example is described in which a part of the module housing 22 is arranged between the second holding portion 14b of the base unit 1 and the guide portion 15 when the connection unit 2a is held on the base unit 1, but in the fourth embodiment, an example is described in which a protrusion is provided between the guide portion 15 and the module housing 22. Specifically, the guide portion 15 and the module housing 22 are different from the first embodiment in that they have a protrusion protruding in the lateral direction, so the following describes the difference.

[0089] like Fig.19 As shown, the front cover 12a has a plurality of guides 15 formed in a manner extending in the longitudinal direction from the other end of the front cover 12a. The guide 15 is a hollow rectangular parallelepiped shape with both sides open in the height direction. The guide 15 has a protrusion 15a protruding in the lateral direction. The protrusion 15a is formed on the far end side of the surface parallel to the longitudinal direction of the guide 15. In addition, two protrusions 15a are formed parallel to the height direction for one surface. That is, four protrusions 15a are formed for one guide 15.

[0090] like Fig. 20 As shown, the connection unit 2a has a module housing 22. When the connection unit 2a is held in the base unit 1, a protrusion 22d protruding in the lateral direction is provided on the proximal side of the surface of the module housing 22 adjacent to the guide portion 15. The protrusion 22d is formed one on each side in the lateral direction.

[0091] Fig.21 The diagram shows an enlarged top view of the adjacent portion between the guide portion 15 and the module housing 22 when an external force is applied from the lateral direction. If an external force is applied to the connection unit 2a from the lateral direction, a portion of the module housing 22 sandwiched between the second retaining portion 14b and the guide portion 15 contacts the second retaining portion 14b, and the protrusion 22d of the module housing 22 contacts the guide portion 15. By forming the protrusion 22d as shown above, the lateral movement of the connection unit 2a can be restricted earlier than when the protrusion 22d is not formed. Therefore, the load on the gasket 30 can be further reduced. Therefore, the gasket 30 becomes less susceptible to damage caused by twisting or wear, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0092] In addition, if an external force is applied to the connection unit 2a from a direction opposite to the above direction, a portion of the module housing 22 sandwiched between the second holding portion 14b and the guide portion 15 contacts the second holding portion 14b, and a portion of the module housing 22 contacts the protrusion 15a of the guide portion 15. By forming the protrusion 15a as shown above, the lateral movement of the connection unit 2a can be restricted earlier than when the protrusion 15a is not formed. In other words, the shaking of the connection unit 2a can be suppressed, so the load on the gasket 30 can be further reduced. Therefore, the gasket 30 becomes less likely to be damaged by twisting or abrasion, and the waterproofness or dustproofness based on the gasket 30 can be made durable.

[0093] Furthermore, a projection may be provided on the surface of the second holding portion 14 b adjacent to the module case 22 .

[0094] Furthermore, the projection 15a of the guide portion 15 may be formed on the proximal side, and the projection 22d of the module housing 22 may be formed on the distal side.

[0095] Furthermore, when the module case 22 does not have the projection 22d, the projections 15a and 22d may be formed on the guide portion 15. Similarly, when the guide portion 15 does not have the projection 15a, the module case 22 may have the projection 15a and 22d.

[0096] In embodiments 1 to 4, different structures and examples of their combination are described with respect to a pair of retaining parts 14, guide parts 15, 17, and the engaging part 21, but the embodiments are not limited to this. For example, in order to make the waterproofness or dustproofness based on the gasket 30 last, a scheme other than the combination of structures described in each embodiment can be adopted. Specifically, inclined surfaces inclined in directions different from each other such as the lateral and height directions may be provided in the pair of retaining parts 14 and the engaging part 21. In addition, an inclined surface may be provided in one of the pair of retaining parts 14 and the engaging part 21. In addition, the pair of retaining parts 14 may also be configured to have multiple inclined surfaces with different directions, and the engaging part 21 may also be configured to have multiple inclined surfaces with different directions. In addition, the guide parts 15, 17 may also be used in combination with the pair of retaining parts 14 and the engaging part 21 described in other embodiments.

[0097] Description of the label

[0098] 1 base unit, 10 substrate, 11 base side connector, 12 base housing, 13 opening, 14 a pair of holding portions, 14a first holding portion, 14b second holding portion, 15 guide portion, 15a projection, 2 module unit, 17 guide portion, 2a connection unit, 20 module side connector, 21 engaging portion, 21a first engaging portion, 21b second engaging portion, 22 module housing, 22a fitting portion, 22b recess, 22c recess, 22d projection, 30 gasket, 31 leaf spring, 4a inclined surface, 4b inclined surface, 4c inclined surface, 4d inclined surface, 4e inclined surface, 5a inclined surface, 5b inclined surface, 5c inclined surface, 5d inclined surface, 5e inclined surface, 5f inclined surface

Claims

1. A programmable logic controller comprising a base unit and a plurality of module units connected to the base unit, In the programmable logic controller, The base unit has: a substrate having a plurality of base-side connectors, the substrate electrically connecting the plurality of module units via the plurality of base-side connectors; a base housing having an opening for exposing one of the plurality of base-side connectors, the base housing housing the substrate; and a holding unit that holds one of the plurality of module units, namely, a connection unit, The connecting unit has: a module-side connector connected to one of the plurality of base-side connectors; a snap-fitting portion that is snap-fitted to the holding portion of the base unit in a detachable manner; and a module housing having a fitting portion that fits with the base housing, the fitting portion being arranged so as to surround the module-side connector; The programmable logic controller has: an elastic member that applies a force in a first direction in which the connection unit is away from the base unit, so as to press the engaging portion of the connection unit against the holding portion of the base unit; and a sealing material that seals a gap between the base housing and the fitting portion of the module housing, The holding portion is provided in plurality to form a pair, The pair of holding portions has inclined surfaces inclined with respect to the first direction so as to apply the force generated by the elastic member to a second direction intersecting the first direction.

2. The programmable logic controller according to claim 1, wherein: The sealing material is provided on a side surface of the fitting portion which is parallel to the first direction, or on a surface of the base housing which faces the side surface of the fitting portion.

3. The programmable logic controller according to claim 1 or 2, wherein: The second direction is parallel to a direction from one of the pair of holding portions toward the other holding portion, The inclined surface is inclined so as to gradually approach the other holding portion side toward the first direction.

4. The programmable logic controller according to claim 1 or 2, wherein: The second direction is a direction orthogonal to the first direction and a direction from one of the pair of holding parts toward the other holding part. A plurality of the inclined surfaces are provided so as to sandwich the engaging portion of the connecting unit from both sides, and intervals between the inclined surfaces gradually narrow toward the first direction, thereby applying the force generated by the elastic member in the second direction.

5. The programmable logic controller according to claim 1 or 2, wherein: The engaging portion has an inclined surface inclined with respect to the first direction so as to apply the force generated by the elastic member to a second direction intersecting the first direction.

6. The programmable logic controller according to claim 5, wherein: The second direction is parallel to a direction from one of the pair of holding portions toward the other holding portion, The inclined surface is inclined so as to gradually approach the other holding portion side from the one holding portion side toward the first direction.

7. The programmable logic controller according to claim 5, wherein: The second direction is a direction orthogonal to the first direction and a direction from one of the pair of holding parts toward the other holding part. The engaging portion has a plurality of inclined surfaces inclined so that a width in the second direction gradually narrows toward the first direction.

8. The programmable logic controller according to claim 1 or 2, wherein: The module case has a plurality of inclined surfaces provided so as to sandwich the engaging portion from both sides, and intervals between the inclined surfaces gradually widen toward the first direction.

9. The programmable logic controller according to claim 1 or 2, wherein: The base unit further includes a plurality of guide portions formed so as to extend in the first direction. The module housing has a recessed portion formed along the plurality of guide portions. When the connection unit is held by the base unit, at least two of the plurality of guide portions are adjacent to the module housing.

10. The programmable logic controller according to claim 9, wherein: At least one of a surface of the guide portion adjacent to the module housing and a surface of the module housing adjacent to the guide portion has a protrusion.

11. The programmable logic controller according to claim 9, wherein: The guide portion has an inclined surface that is inclined so that its width gradually narrows toward the first direction.

12. A base unit of a programmable logic controller, the programmable logic controller comprising a base unit and a plurality of module units connected to the base unit. in, The base unit of the programmable logic controller has: a substrate having a plurality of base-side connectors, the substrate electrically connecting the plurality of module units via the plurality of base-side connectors; a base housing having an opening for exposing the plurality of base-side connectors, the base housing housing the substrate; a holding portion engaged with an engaging portion of a connecting unit, one of the plurality of module units, to hold the module unit; an elastic member that applies a force in a first direction in which the connection unit is away from the base unit, so as to press the engaging portion of the connection unit against the holding portion of the base unit; and a sealing material that seals a gap between a fitting portion of the module housing of the connection unit and the base housing, the fitting portion being provided to surround the module-side connector of the connection unit connected to one of the plurality of base-side connectors, and the fitting portion being fitted with the base housing, The holding portion is provided in plurality to form a pair, The pair of holding portions has inclined surfaces inclined with respect to the first direction so as to apply the force generated by the elastic member to a second direction intersecting the first direction.

13. A module unit of a programmable logic controller, the programmable logic controller having a base unit and a module unit connected to the base unit, the base unit having: a substrate having a plurality of base-side connectors; a base housing having an opening for exposing one of the plurality of base-side connectors, the base housing accommodating the substrate; and a holding portion for holding other units. in, The module unit of the programmable logic controller has: a module-side connector connected to one of the base-side connectors of the base unit; A snap-fitting portion, which is snap-fitted with the holding portion of the base unit in a freely detachable manner; a module housing having a fitting portion that fits with the base housing of the base unit, the fitting portion being provided so as to surround the module-side connector; an elastic member that applies a force in a first direction in which the module unit is away from the base unit, so as to press the engaging portion of the module unit against the holding portion of the base unit; and a sealing material that seals a gap between the base housing and the fitting portion of the module housing, The holding portion is provided in plurality to form a pair, The pair of holding portions has inclined surfaces inclined with respect to the first direction so as to apply the force generated by the elastic member to a second direction intersecting the first direction.

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