Electrical device for connection to an external device

Abstract

Electrical device (10), comprising: a housing (3) having a hollow shape and an opening (31) in a part of the housing (3) and comprising an electrical component connected to an external device; a connection section (91) which is connected to the electrical component in the housing (3) and is arranged in a position opposite the opening (31); a plurality of terminal blocks (41, 42), each of which has the following features: one of a multitude of external connecting elements (100) that are connected to the external device and have different shapes from each other and one of a plurality of internal connecting elements (101) which are connected to the connecting section (91) and have an identical shape to each other, and wherein the plurality of connecting blocks (41, 42) can be selectively installed in the opening (31), wherein Each of the multiple connection blocks (41, 42) includes: a main body (411) which exposes and holds the internal connecting element (101) on a surface facing the connection section (91) when it is attached to the opening (31), and a cover body (412) which is fitted into a rear surface of the main body (411) and whose circumference is in contact with the opening (31) when the connection block (41) is attached to the opening (31), wherein the lid body (412) includes a shoulder into which sealing resin has penetrated around the circumference of the lid body (412), the internal connecting elements (101) are electrically connected to the connection section (91) when any one of the plurality of connection blocks (41, 42) is inserted into the opening (31), and which is attached to the opening (31) by the sealing resin from the multitude of connection blocks (41, 42).

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an electrical device which can be connected to an external device with a plurality of connection system designs and which is connected to the external device by means of a connection system selected from the plurality of connection system designs.

[0002] As disclosed in Japanese Patent Application Laid-Open No. JP 2004-128422 A, some electrical devices are connected to an external device via a power source line, a signal line, and the like to receive power from the external device's power source and transmit signals to and from the external device. For example, a photoelectric switch capable of optically detecting the presence or absence of an object is connected to the external device via a power source line for supplying power to a light source and a control unit, and a signal line for outputting a detection signal.

[0003] When connecting between the electrical device and the external device, a connection type suitable for use is optionally selected from a variety of connection systems, such as a cable system in which a cable is directly connected to an electrical device and a connector system in which a plug at one end of a cable can be connected and disconnected from a socket of the electrical device.

[0004] In view of the above, in some conventional electrical devices connected to external devices, a cable or a socket may be selectively soldered to a terminal portion arranged on a base plate in a main body to share component parts between the cable system and the connector system.

[0005] However, conventional electrical devices must be soldered to the terminal portion of the base plate of a plug or a socket during an intermediate assembly step before being mounted on a base plate in the main body.

[0006] Therefore, the assembly processes following the insertion of the base plate into the main body of the electrical device cannot be standardized between the cable system type and the connector system type, resulting in complex parts inspection and the inability to simplify the assembly process. In particular, the assembly process for connecting the cable to the electrical device is complicated in the cable system type after the cable is soldered to the terminal sections of the base plate.

[0007] Such problems usually occur not only with a photoelectric switch, but with any electrical device that can be used with a variety of connection systems to connect it to an external device.

[0008] Printed prior art in the present technical field, which reflects the preamble of claim 1, is disclosed in the documents US 6 215 656 B1, DE 295 21 213 U1, US 5 501 608 A, US 6 292 371 B1 and DE 20 2005 015 971 U1.

[0009] An object of the present invention is therefore to provide an electrical device capable of connecting a connecting element, such as a cable and a socket, to a terminal portion of a base plate after inserting the base plate into the main body in a final assembly step, thereby standardizing most of the assembly steps for a variety of types of electrical devices and simplifying the assembly process. SUMMARY OF THE INVENTION

[0010] The object of the invention is achieved by an electrical device having the features of claim 1, advantageous developments emerge from the subclaims.

[0011] An electrical device according to the present invention comprises a housing, a terminal portion, and a plurality of terminal blocks. The housing has a hollow shape with an opening in a part of the housing and has an electrical component connected to an external device. The terminal is connected to the electrical component in the housing and is arranged in a position opposite to the opening. Each terminal block of the plurality of terminal blocks has one of a plurality of external connecting elements connected to the external device and has a different shape from one another, and has one of the plurality of internal connecting elements connected to the terminal portion and having an identical shape to one another, wherein one terminal block of the plurality of terminal blocks is selectively insertable into the opening.If any one of the plurality of terminal blocks is inserted into the opening, the internal connecting element is electrically connected to the terminal section. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a photoelectric switch according to an embodiment of the present invention; Fig. 2 is a perspective view of the photoelectric switch from the rear end; Fig. 3 is a perspective view of a first terminal block included in the photoelectric switch; Fig. 4 is a perspective view of a second terminal block included in the photoelectric switch; Fig. 5 is a view showing a mounting state of the first terminal block with the photoelectric switch, and Fig. 6 is a view showing an attachment state of the second connection block with the photoelectric switch. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a photoelectric switch as an example of an electrical device according to an embodiment of the present invention will be described with reference to the drawings.

[0013] As in Fig. 1, the photoelectric switch 10 is formed with a housing 1, a support member 2, a cover 3, a lens unit 4, a filter 5, a front cover 6, control knobs 7A and 7B, and a cover 8 for the controls.

[0014] The housing 1 has upper and lower recesses 11 and 12 that are open at the front and rear. The support element 2 carries a base plate 9 and is inserted into the housing 1 from the rear end. The cover 3 is attached to the housing 1 from the rear end to enclose the rear surface and two side surfaces of the housing 1 and, together with the housing 1, forms part of the housing defined according to the present invention. The lens unit 4 is a tubular element that is open at the front and rear and is inserted into the recess 12 from the front end of the housing 1. The filter 5 is attached to the end of the recess 11. The front cover 6 covers the front ends of the recesses 11 and 12. The control knobs 7A and 7B are received in hole sections 13 and 14, respectively, from the top of the housing 1 and fitted into the controls 15 and 16, which are fixed on the base plate 9.The control cover 8 covers the upper surface of the control knobs 7A and 7B.

[0015] As in Fig. As shown in Figure 2, the cover 3 is attached to the rear end of the housing 1. Before attaching the cover 3 to the housing 1, the electrical component is mounted on the base plate 9, the base plate 9 is attached to the support element 2, the support element 2 is fitted into the housing 1, the control knobs 7A and 7B are fitted to the housing 1, and the control cover 8 is attached to the housing 1 in the order mentioned.

[0016] An opening 31 is formed in the rear surface 3A and the lower side surface 3B of the cover 3. The opening 31 has a recess 32 in the side surface 3B. A first connecting block 41 or a second connecting block 42, which will be described later, is inserted into the opening 31. A hole portion 34 is formed on two side surfaces forming the opening 31 at a position opposite to each other. The hole portions 34 are formed correspondingly to the case-side engaging elements defined by the present invention. A shoulder 33 is formed around both side surfaces 3C and 3D of the cover 3. When the assembled photoelectric switch 10 is sealed with a resin, the sealing resin penetrates into the shoulder 33, so that the sealing resin securely adheres to the surface of the cover 3.

[0017] Three terminals 91 are mounted on the base plate 9, which is supported by the support member 2. Each of the terminals 91 is electrically connected to other electrical components on the base plate 9 through the leads printed on the base plate 9. For example, each of the terminals 91 can be formed as a plate-like element with a slot in the central part that cuts through the insulation of a covered wire, which is inserted into the slot and thus contacts an electrically conductive strand in the covered wire. The terminals 91 protrude into the opening 31 in a position in which the cover 3 is applied to the housing 1 and can thus be visually identified from the outside.

[0018] As in Fig. 3, the first connection block 41 includes a main body 411 and a cover body 412. The cover body 412 is fitted into the rear surface of the main body 411. The main body 411 includes a recess 4111 in the lower end face and further includes three recesses 4112 in the main body 411. The cover body 412 includes a recess 4121 in the lower end face. In a state where the cover body 412 is fitted into the rear surface of the main body 411, the recess 4111 and the recess 4121 form a circular recess. The main body 411 and the cover bodies 412 accommodate therebetween a cable 100 passing through the recesses 4111 and 4121 and inserted into the main body 411.

[0019] The main body 411 includes a protrusion 4114 on each of two side surfaces formed parallel to each other. The protrusion 4114 corresponds to the block-side engagement element defined in the present invention and resiliently engages each of the hole portions 34 of the housing 3 from the interior of the housing 3.

[0020] The three covered wires 101 of the cable 100 are separated from each other in the main body 411 and inserted into the recesses 4112. Each of the covered wires 101 is partially arranged on the front end face of the main body 411 and is supported in the recesses 4112. The first connecting block 41 is fitted into the opening 31 and is shaped to cover the opening 31.

[0021] The cover body 412 includes a recess 4122 around the cover body 412. When sealing resin for sealing the photoelectric switch 10 penetrates into the recess 4122, the sealing resin can securely adhere to the surface of the first connection block 41.

[0022] It should be noted that the cable 100 corresponds to the external connecting element defined by the present invention and similarly the sheathed wire 101 corresponds to the internal connecting element in the sense of the present invention.

[0023] The shoulder 4122 can also be formed with a groove section. The following section is comparable to the above section.

[0024] As in Fig. 4, the second connection block 42 includes a main body 421 and a cover body 422. The cover body 422 is attached to the rear surface of the main body 421. The main body 421 has a recess 4211 in the lower end face and further includes three recesses 4212 in the main body 421. The cover body 422 has a recess 4221 in the lower end face. In a state where the cover body 422 is fitted into the rear surface of the main body 421, the recess 4211 and the recess 4221 form a cylindrical recess. The main body 421 and the cover body 422 hold therebetween a connector (socket) 200 inserted into the recesses 4211 and 4221.

[0025] Three covered wires 201 are exposed on the connector 200. The three covered wires 201 are each inserted into the recesses 4212 in the main body 421, separated from each other. Each of the covered wires 201 is partially supported in the recesses 4212 at the front end of the main body 421. The second connection block 42 is fitted into the opening 31 and shaped to cover the opening 31.

[0026] The cover body 422 includes a recess 4222 around the cover body 422. When sealing resin for sealing the photoelectric switch 10 penetrates into the recess 4222, the sealing resin can securely adhere to the surface of the second connection block 42.

[0027] The cover body 422 has a projection 4224 on each of its two side surfaces, which are formed parallel to each other. The projection 4224 corresponds to the block-side engagement part in the sense of the present invention and resiliently engages each of the hole portions 34 of the housing 3 from the interior of the housing 3.

[0028] It should be noted that the connector 200 corresponds to the external connection element in the sense of the present invention and similarly the sheathed wire 201 corresponds to the internal connection element in the sense of the present invention.

[0029] As in Fig. 5, a wire connector type photoelectric switch 10A is obtained by fitting the first connection block 41 into the opening 31 of the housing 3 in the housing 1. When the first connection block 41 is inserted into the opening 31, the three covered wires 101 (see Fig. ) exposed to the front side surface of the main body 411 of the first connection block 41 are respectively inserted into the slot of the three terminals 91 in the housing 1 and electrically connected to each of the terminals 91. Further, the projection 4114 of the first connection block 41 resiliently engages each of the hole portions 34 of the housing 3 from the inside of the housing 3, and a state is obtained in which the first connection block 41 is fitted into the opening 31 of the housing 3.

[0030] The main body 411 of the first connecting block 41 has a projection 4113. The projection 4113 closes the recess 32 when the first connecting block 41 is fitted into the opening.

[0031] When one end of the cable 100 is connected to an external device not shown, the photoelectric switch 10A can be connected to the external device through the cable 100.

[0032] As in Fig. 6, a plug-in type photoelectric switch 10B is obtained by fitting the first connection block 42 into the opening 31 of the housing 3 in the housing 1. When the second connection block 42 is inserted into the opening 31, the three covered wires 201 (see Fig. ) exposed to the front side surface of the main body 421 of the second connection block 42 are respectively inserted into the slot of the three terminals 91 in the housing 1 and electrically connected to each of the terminals 91. Further, the projection 4224 of the second connection block 42 resiliently engages each of the hole portions 34 of the housing 3 from the inside of the housing 3, and a state is obtained in which the second connection block 42 is fitted into the opening 31 of the housing 3.

[0033] A part of the peripheral surface of the connector 200 of the second connection block 42, which is exposed when the first connection block 41 is fitted into the opening 31, is inserted into the recess 32 to cover the recess 32.

[0034] When a connector (a plug) connected to one end of a cable coming from an external device (not shown) is inserted into the connector 200, the photoelectric switch 10B can be connected to the external device via the connector 200.

[0035] As stated above, the wire connector type photoelectric switch 10A and the plug-in type photoelectric switch 10B can be manufactured by selectively inserting either the first connection block 41 or the second connection block 42 into the opening 31. The process of fitting the first connection block 41 or the second connection block 42 into the opening 31 constitutes the final process in the assembly of the photoelectric switch 10A or 10B, except for sealing with sealing resin, so that the processes up to this process can be unified and the assembly can be simplified.

[0036] The above-described embodiments should be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined not by the above-described embodiments, but by the claims. Furthermore, it is intended that all modifications that are within the interpretation or scope of the claims, as well as equivalents, be embraced by the present invention. The electrical device is not limited to the photoelectric switch and can also be applied, for example, to other electrical devices that can be selectively connected to an external device through any connection selected from a variety of connection types. Furthermore, the variety of connection types is not limited to the combination of cable connector systems and plug-in connector systems.

Claims

[1] Electrical device (10) comprising: a housing (3) having a hollow shape and having an opening (31) in a part of the housing (3) and comprising an electrical component connected to an external device; a terminal portion (91) connected to the electrical component in the housing (3) and arranged in a position opposite the opening (31); a plurality of terminal blocks (41, 42), each comprising: one of a plurality of external connecting elements (100) connected to the external device and having a different shape from one another, and one of a plurality of internal connecting elements (101) connected to the connecting portion (91) and having a mutually identical shape, and wherein the plurality of connecting blocks (41, 42) are selectively mountable in the opening (31), wherein each of the plurality of terminal blocks (41, 42) comprises: a main body (411) exposing and holding the internal connecting element (101) on a surface facing the terminal portion (91) when it is attached to the opening (31), and a cover body (412) fitted into a rear surface of the main body (411) and whose periphery is in contact with the opening (31) when the terminal block (41) is attached to the opening (31), wherein the lid body (412) comprises a shoulder into which sealing resin has penetrated around the circumference of the lid body (412), the internal connecting elements (101) are electrically connected to the terminal section (91) when any one of the plurality of terminal blocks (41, 42) is inserted into the opening (31), and any one of the plurality of terminal blocks (41, 42) is fixed to the opening (31) by the sealing resin. [2] The electrical device (10) according to claim 1, wherein the main body (411) and the cover body (412) each have mutually facing recesses (4111; 4121) through which a hole portion (34) for holding the external connecting member (100) is formed when the cover body (412) is fitted into the rear surface of the main body (411). [3] Electrical device (10) according to claim 1 or 2, wherein the internal connecting element (101) is a sheathed cable, wherein the connecting portion (91) is a plate-shaped element having a slot into which the covered wire is inserted, and when attaching the terminal block (41) to the opening (31), the terminal section (91) cuts through an insulation of the covered wire inserted into the slot and then contacts an electrically conductive wire inside the covered wire, so that the covered wire is electrically connected to the terminal section (91). [4] The electrical device (10) according to any one of claims 1 to 3, wherein the housing (3) has a housing-side engaging member (34) in the opening (31), and each terminal block (41, 42) of the plurality of terminal blocks (41, 42) has a block-side engaging member (4114) resiliently engaging the housing-side engaging member (34). [5] The electrical device (10) according to any one of claims 1 to 4, wherein the plurality of terminal blocks (41, 42) comprise a first terminal block (41) and a second terminal block (42), and wherein each of the external connecting elements (100) is a cable and a connector. [6] The electrical device (10) according to claim 5, wherein the opening (31) has a recess (32) into which a part of a peripheral surface of the connector is fitted, and the first terminal block (41) has a protruding part (4113) closing the recess (32).

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