JPS6328497Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is constructed by incorporating the switch body into a case with a cover. For example, it relates to improvements in switches used as limit switches.

The limit switch mentioned above is assembled by housing the switch body inside a metal case, but since the lead end that becomes the live part is exposed on the switch body, the lead terminal part of the switch body and the metal case are exposed. It is necessary to provide insulation by inserting an insulating material between the case and the case. Furthermore, in order to prevent water from entering the case with a cover from the outside, a seal is applied to the joint between the case and the case cover. In this case, assembling the insulating member and the sealing member as separate parts increases the number of parts and the number of man-hours required to assemble the switch. For this reason, for the purpose of simplifying the structure and reducing assembly man-hours, a structure has been implemented in which the insulating member and the sealing member are combined into one part, as shown in Figure 1a and b. There is.

That is, in FIGS. 1a and 1b, 1 is the switch body, 2 is a case that houses the switch body, and 3 is a head section equipped with, for example, a roller type actuator 31, which directs the movement of the actuator 31 to one side of the case 2. Plunger 3 inserted into the opening hole
The switch body 1 is configured to open and close the contact mechanism of the switch body 1 in accordance with the second stroke displacement. Further, the switch main body 1 has the above-mentioned contact mechanism built therein, and a lead terminal 11 for wiring a lead wire is exposed on the front surface thereof. On the other hand, the case 2 consists of a case body 21 and a case cover 22 that covers the front of the case body.
2 is tightened and fixed to the case body 21 with bolts 23. Furthermore, the case body 21 has a hole 24 for the plunger 32 described above on one side, and a lead-out hole 25 for drawing out a lead wire (not shown) on the other side. Here, case body 21 and case cover 22
A gasket 4, which also serves as the above-mentioned insulating member, is inserted between the two. This gasket 4 includes a flange portion 41 interposed between the cover mounting flange surface of the case body 21 and the case cover 22, a front portion 42 that covers the front area of the switch body 1, and a front portion 42 that surrounds the entire circumference of the switch body 1. A side wall portion 43 that fits between the case body 21 and the inner wall thereof is integrally molded, and cutouts 44 and 45 are provided at locations corresponding to the aforementioned holes 24 and 25 opening in the case body 21. It is formed. With this configuration, the seal between the case body 21 and the case cover 22 is achieved by the flange portion 41 that is clamped between them, and the insulation between the lead terminal portion of the switch body 1 and the case is achieved by the side wall portion. 43 and the front part 42. The switch body 1 is the case body 2.
1 with screws 12.

However, while the conventional structure described above has the advantage of reducing the number of parts and assembly man-hours, it has the following difficulties when assembling the gasket. That is, the gasket 4 has a side wall portion 43 that surrounds the entire circumference of the switch body 1. Therefore, when the gasket 4 is placed on the case body 21 from the front, the case body 2
The interior of 1 cannot be seen from the front.
For this reason, if the gasket 4 is not installed accurately even to some extent, the position of the notch 44 in the side wall 43 of the gasket may shift, interfering with the plunger 32, and causing the switch to operate slowly or become impossible. be. Moreover, since the work of covering the case body 21 with the gasket is performed at the place of use each time the switch is being wired or inspected for maintenance, even after the switch is shipped from the factory, such troubles are more likely to occur. A solution to this point is strongly desired. For this reason, in some cases the front part 42 of the gasket 4 has a double-door structure, but the structure becomes complicated and the advantages of integrating the parts cannot be fully utilized.

The purpose of this invention is to provide a switch that is easier to assemble and has a simpler structure without reducing the insulation between the lead terminal portion of the switch body and the case.

This invention will be explained in detail below based on the embodiments shown in FIGS. 2 to 4. Compared to the conventional structure described above, the structure of this embodiment has improvements in the structure of the switch body, the support system for the switch body, and the structure of the gasket. That is, first, the switch body 1 is connected to the lead terminal 1 as shown in FIG.
1, the switch body 1 is arranged so as to surround the lead terminal 11 on three sides excluding the side from which the lead wire 13 is pulled out.
A screen-shaped side wall 14 that rises forward from the outer periphery is integrally formed on the. This side wall 1
The height of 4 is set so that the peripheral edge 15 of the side wall 14 is aligned on almost the same plane as the opening edge of the case body 21 when the switch body 1 is accommodated in the case body 21 as shown in FIG. 2b. ing. Further, the switch body 1 is not provided with a screw for attaching it to the case body 21, and is assembled into the case body 21 at a predetermined attachment position in a fitting manner. For this purpose, as shown in FIG. 2b, an engaging protrusion 26 is formed on the bottom surface of the case body 21, and an engaging hole 16 is formed in the switch body 1 opposite to this. On the other hand, case body 2
A gasket 5 is interposed between the case cover 1 and the case cover 22, as in the conventional case. This gasket 5 is made of an elastic insulating material such as silicone rubber, and its structure includes a front part 51 that has almost the same shape as the case cover and a cap that protrudes rearward from the front part 51, as shown in FIG. A letter-shaped tongue piece 52 is integrally molded. Furthermore, a notch 53 is formed in the tongue portion 52 for drawing out the lead wire 13 described above. . Note that 54 is a bolt through hole. Also, the case body 21
2, there is a flange surface 2 around the front opening.
A rib 28 protruding forward from the bolt 2
A protruding stopper 29 that directly abuts the case cover 22 is integrally formed near the tightening point 3. In FIG. 4, the gasket 5 is provided with a notch 55 for escape of the stopper 29.

The assembly structure of each of the above parts is as shown in FIGS. 2a and 2b. The switch body 1 is positioned and set at a predetermined position in the case body 21 by fitting an engagement protrusion 26 and an engagement hole 16, while the gasket 5 is positioned between the case body 21 and the case cover 2.
2, and are integrally fastened with bolts 23. In this state, the entire circumference of the gasket 5 is first brought into pressure contact with the rib 28 of the case body 21, so that sufficient sealing performance can be obtained. Moreover, the case cover 22 directly contacts the stopper 29 to regulate the tightening margin of the gasket 5, thereby preventing the gasket 5 from being pressed more than necessary and causing deterioration. Further, the gasket 5 is in pressure contact with the side wall periphery 15 of the switch body 1 in the assembled state, so that the switch body 1 is held pressed between it and the bottom wall of the case body 21. Therefore, the mounting bolt 1 of the switch body as shown in Fig.
2 is unnecessary, and this space can be used to expand the space for arranging the lead terminals 11. Furthermore, the insulation between the lead terminal 11 of the switch body 1 and the case 2 is first
The remaining front surface and the lead wire extraction side are formed by the front surface portion 51 and the tongue portion 52 of the gasket 5. That is, by providing the screen-like side wall 14 on the switch body 1, it is sufficient to provide the tongue portion 52 that slightly protrudes toward the lead wire side of the switch body on the gasket side, and on the side where the plunger 32 of the movable part is located. This eliminates the need for gasket side walls. Therefore, when assembling the gasket 5 into the case, there is no need to take into account interference with the plunger 32, and even if there is a slight deviation in the installation method, there is no risk of affecting the operation of the switch. This will make the work easier.

As described above, according to the configuration of this invention, there is no fear of the gasket interfering with the movable parts of the switch, which was seen in conventional switches, so it is possible to improve assembly workability, and also to improve the lead of the switch body. The insulation between the terminal and the case is completely achieved by the side wall integrally molded into the switch body, as well as the front part and tongue part of the gasket, so it is more effective than switches with conventional structures. There is no reduction in insulation properties. In addition, by tightening and fixing the case cover, the switch body is pressed and held within the case body via the gasket, and even if there are variations in the finish of individual components, the gasket acts as a part tolerance buffer, so The switch body is housed in the case without wobbling, and a stable sealing effect can be expected at all times. According to a preferred embodiment, a fitting portion is provided between the case and the switch body for positioning the switch body at a predetermined mounting position within the case, so that mounting of the switch body to the case is easy. becomes easier. Furthermore, by providing ribs and stoppers on the case body, it is possible to further improve sealing performance and prevent deterioration of the gasket.

[Brief explanation of the drawing]

Figures 1a and 2a are front views of switches based on the conventional and embodiments of the present invention with case covers removed, respectively, Figure 1b and Figure 2b
are the side sectional view of Figure 1a, Figure 2a, and Figure 3, respectively.
This figure and FIG. 4 are external perspective views of the switch body and gasket in FIG. 2. 1...Switch body, 11...Lead terminal, 1
3... Lead wire, 14... Screen-shaped side wall, 2... Case, 21... Case body, 22... Case cover, 26... Engaging protrusion for fitting and engaging with the switch body, 28... Rib, 29...stoppa, 5...
...gasket, 51...front part, 52...tongue part.

Claims (1)

[Claims for Utility Model Registration] 1. A switch body having a lead terminal portion exposed on the front side, the front side being open and accommodating the switch body inside, and a plunger for operating the switch being slidably disposed on one side. The case body has an outlet for the lead wire connected to the lead terminal section of the switch body on the side, a case cover that covers the opening of this case body, and a case cover that covers the front side of the case body and connects the lead terminal section of the switch body and the case. In the switch, the switch body has a front part that insulates between the switch body and the case cover, and a gasket that is inserted between the case body and the case cover and serves as both an insulator and a seal. A screen-like side wall is integrally formed that rises from the outer periphery of the switch body toward the front so as to surround the lead terminal portion on three sides excluding the case body, and whose peripheral edge is aligned on the same plane as the opening edge of the case body. The gasket is provided with a tongue piece that is inserted between the lead wire pull-out side of the switch body and the inner wall surface of the case at the mounting position, and the switch body is pressed and held within the case body through the gasket by tightening and fixing the case cover. A switch characterized by: 2 Utility Model Registration Claims The switch according to claim 1 is characterized in that a fitting and engaging portion is provided between the case and the switch body for positioning the switch body at a predetermined mounting position within the case. A switch with 3. The switch according to Claim 1 of the Utility Model Registration Claim, characterized in that the cover mounting flange surface of the case is provided with a rib that protrudes forward along its circumference. 4. The switch according to Claim 1 of the Utility Model Registration Claim, characterized in that a stopper is provided in a part of the case, protruding from the cover mounting flange surface and directly abutting against the back surface of the case cover.