JPH0339871Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] The present invention relates to a pressure-resistant explosion-proof switch.

[Technical background of the invention and its problems]

FIG. 2 shows a cross-sectional view of a conventional pressure-resistant and explosion-proof switch. A switch element 23 is installed in an explosion-proof chamber 22 covered by a casing 21, and a knob 24 for operating the switch element 23 is installed outside the casing 21. The left end of a joint shaft 25 is screwed into the knob 24, and the switch shaft 26 is connected to the right end of the joint shaft 25.
are screwed together, and when the knob 24 is slid left and right, the switch element is turned on and off via a joint shaft 25 and a switch shaft 26. The joint shaft 25 has an explosion-proof clearance W and an explosion-proof depth L between it and the casing 21.
It is used to ensure that Third
The figure is a sectional view of the casing 21. On the left side, there is a mounting hole 27 into which the joint shaft 25 is inserted;
On the right side, a threaded hole 28 is formed which communicates with this mounting hole 27 and into which the switch shaft 26 is screwed. It is necessary to drill the mounting hole 27 and the screw hole 28 in the casing 21 so that their axes coincide, but it is difficult to process to ensure the accuracy of this concentricity. The switching was malfunctioning. Further, FIG. 4 is a sectional view of the joint shaft 25. A male threaded portion 29 is formed at the left end to be screwed into the knob 24, and a multi-step screw hole 30 into which the switch shaft 26 is screwed is formed at the right end. This male thread part 2
9 and the screw hole 30 are formed so that their axes coincide with each other, but even if this concentricity deviates, the deviation .beta. causes switching malfunction.

[Purpose of invention]

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a pressure-resistant explosion-proof switch that enables smooth switching operation while ensuring explosion-proof clearance and depth.

[Summary of the idea]

In order to achieve the above object, the flameproof explosion-proof switch according to the present invention secures explosion-proof depth by screwing the support for supporting the switch element into the casing, and also provides the support for the switch shaft for switching the switch element. It is slidably inserted into the body to ensure an explosion-proof gap. This eliminates the need for multi-stage hole machining and enables smooth switching operation.

[Example of idea]

Hereinafter, one embodiment of the pressure-resistant explosion-proof switch according to the present invention will be described in detail with reference to the sectional view shown in FIG.

A switch element 3 is provided in a pressure-resistant explosion-proof chamber 2 covered by a casing 1.
A knob 4 for performing switching operations is provided on the outside of the switch. The switch element 3 is a switch box 5
, the terminal 6 protrudes from the switch box 5 into the pressure-resistant explosion-proof chamber 2, and the terminal 6 slides in the axial direction of the terminal 6.
It consists of a terminal plate 7 that comes into contact with the terminal plate 7. The switch box 5 has an open end on the casing 1 side,
A support body 8 is joined to this open end, so that the switch element 3 has a sealed structure. The support body 8 consists of a support plate 9 joined to the switch box 5 and a male threaded shaft 10 screwed into the casing 1. For this reason, a female screw hole 11 into which the male screw shaft 10 of the support body 8 is screwed is formed in the casing 1 so as to pass through the casing 1 from side to side. Therefore, when the male threaded shaft 10 of the support body 8 is screwed into the female threaded hole 11,
The depth L for explosion protection is ensured by the screw length. Further, this female threaded hole 11 only needs to be formed so as to penetrate through the casing 1.
There is no need for multi-step hole machining, so no misalignment of the axis occurs. In addition, such a male threaded shaft 10
When screwing into the female screw hole 11, a pin (not shown) or the like is attached to prevent rotation.

A slide hole 12 is formed through the support body 9 in the axial direction, and a switch shaft 13 is slidably inserted through the slide hole 12. The left end of this switch shaft 13 is screwed into the knob 4, and the right end is connected to the switch element 3.
When the knob 4 is slid left and right, the switch shaft 13 slides in the same direction to turn the switch element 3 ON and OFF.
It acts like this. Since the switch shaft 13 is slidably inserted into the slide hole 12 in this way, an explosion-proof gap W is secured between the switch shaft 13 and the support 8.
Since the slide hole 12 does not need to be multi-staged and is formed by a single hole machining, the switching operation can be performed smoothly without causing any deviation of the axis.

[Effect of idea]

As described above, according to the present invention, since the support for supporting the switch element is screwed into the casing, the explosion-proof depth can be ensured, and since the switch shaft that performs switching is slidably inserted into the support, the explosion-proof depth can be secured. A gap can be secured. Also, since the conventional joint shaft is no longer required, multi-stage hole machining and multi-stage shaft machining are no longer necessary.
No misalignment of the axis occurs. Therefore, there is an effect that the switching operation can be performed smoothly.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a sectional view of a conventional example, and FIGS. 3 and 4 are sectional views of its casing and joint shaft. 1... Casing, 2... Flameproof chamber, 3...
Switch element, 4...Knob, 8...Support, 11
...Screw hole, 13...Switch shaft.

Claims (1)

[Claims for Utility Model Registration] A pressure-resistant explosion-proof switch in which a switch element is provided inside a pressure-resistant explosion-proof chamber covered by a casing, and the switch element is switched by operating a knob attached to the outside of the casing, A screw hole formed to penetrate the casing, a support that is screwed into the screw hole and supports the switch element, and a switch shaft that is slidably inserted into the support and performs the switching. A pressure-resistant and explosion-proof switch.