Summary of the invention
The technical problems to be solved in the utility model is: at the problem of above-mentioned existence provide a kind of simple in structure, cost is low, reliable operation, easy to operate explosion-proof key switch.
The technical scheme that the utility model adopted is: explosion-proof key switch, have switch base and cover plate, establish interconnective switch lock core and rotating shaft in the described switch base, the rotating shaft output passes cover plate and extends the switch base outside, the sensitive switch that matches with the rotating shaft output is installed on the cover plate, it is characterized in that: described rotating shaft input is installed on the switch base by the copper sheathing of overcoat, copper sheathing respectively with rotating shaft, space between the switch base is less than 0.2mm, and the length in this space is greater than 12.5mm, less than 30mm, have breach on the end face of described rotating shaft output, be installed in one side setting of elastic rod power end and the contacted roller of the vertical tangent plane of breach on the sensitive switch, elastic rod power end opposite side contacts with moving contact.
Described rotating shaft middle part is greater than rotating shaft diameter and integrated with it disk, in the space between this disk flush switch seat and the cover plate, offers two pits on this disk one side end face, offers blind hole accordingly on switch base, places spring and steel ball in the hole.
Install and the axisymmetric alignment pin of blind hole on the described switch base, offer the fluting that matches with alignment pin on the disk, alignment pin rotating maximum angle in fluting is identical with respect to the angle of disc axis with two pits.
Connect by the draw-in groove structure between described switch lock core and the rotating shaft.
The beneficial effects of the utility model are: the utility model shaft input is installed on the switch base by the copper sheathing of overcoat, copper sheathing respectively and the space between the rotating shaft, switch base less than 0.2mm, and the length in this space is greater than 12.5mm, less than 30mm, thereby the explosive flame that has effectively prevented explosive gas mixture reaches the outside by the slit between each parts of switch, utilize common key switch and sensitive switch can realize the explosion prevention function of system, not only simple in structure, easy to operate but also cost is low, easy to maintenance.
Embodiment
As shown in Figure 1 and Figure 2, present embodiment has switch base 2 and cover plate 6, establish interconnective switch lock core 1 and rotating shaft 7 in the described switch base 2, connect by the draw-in groove structure between switch lock core 1 and the rotating shaft 7 in this example, make that rotating shaft 7 can next plays rotation in the effect of switch lock core 1; Rotating shaft 7 outputs pass cover plate 6 and extend switch base 2 outsides, the sensitive switch 9 that matches with rotating shaft 7 outputs is installed on the cover plate 6, described rotating shaft 7 inputs are installed on the switch base 2 by the copper sheathing 5 of overcoat, copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 be 0.1mm, and the length in this space is 25mm, because this space is very little, length is grown (than the space of 0.1mm) simultaneously, thereby can prevent effectively that explosive flame from reaching the outside, to reach explosion-proof effect; Have breach 14 on the end face of described rotating shaft 7 outputs, be installed in elastic rod 16 power ends, one side setting and the contacted roller 15 of breach 14 vertical tangent planes on the sensitive switch 9, elastic rod 16 power end opposite sides contact with moving contact 17.
Described rotating shaft 7 middle parts are greater than rotating shaft 7 diameters and integrated with it disk 10, in the space between this disk flush switch seat 2 and the cover plate 6, make that rotating shaft 7 only can be around its rotational, on this disk one side end face, offer two pits 11, on switch base 2, offer blind hole 12 accordingly, place spring 3 and steel ball 4 in the hole, when arrival is switched on or switched off the position, steel ball 4 enters in the pit 11 under spring 3 self elastic force effect, thereby realizes the excellent handle of driver to the break-make position.
Install and blind hole 12 axisymmetric alignment pins 8 on the described switch base 2, offer the fluting 13 that matches with alignment pin 8 on the disk 10, alignment pin 8 rotating maximum angle in fluting 13 is identical with respect to the angle in disk 10 axle center with two pits 11.When arrival was switched on or switched off the position, alignment pin 8 also arrived two extreme positions of fluting 13 simultaneously respectively, prevents to operate excessive.
The operation principle of present embodiment is: when present embodiment uses in reality, need be in explosion-proof instrument box 18 with its integral installation, be connected by screw between switch base 2 and the explosion-proof instrument box 18, and space between the two is 0.1mm, the length in this space is 25mm, promptly with copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 require identical, to reach explosion-proof effect.When switch was in off-state, steel ball 4 was positioned at one of them pit 11, and alignment pin 8 is near fluting one side positive stop end simultaneously; During concrete work, key is inserted in the switch lock core 1, key drives rotating shaft 7 and rotates, make roller 15 move on the outer circumference surface of rotating shaft 7 from breach 14, deformation takes place elastic rod 16 draws close to sensitive switch 9 bodies, thereby promotes moving contact 17 actions, realizes the connection of power supply, utilize copper sheathing 5 respectively and between the rotating shaft 7, switch base 2, and the elongated spaces between switch base 2 and the explosion-proof instrument box 18 realize the flame proof of system; Simultaneously, steel ball 4 enters in another pit 11, can not only realize the excellent handle of driver to the break-make position, and it is motionless to remain on this position, and alignment pin 8 prevents to operate excessive near the opposite side positive stop end.When needing to stop working off switch, the reverse rotation key, make rotating shaft 7 reverse rotations, roller 15 moves on the breach 14 from the outer circumference surface of rotating shaft 7, elastic rod 16 resets under self elastic force effect, promptly to moving away from sensitive switch 9 body directions, moving contact 17 resets under self elastic force effect simultaneously, realizes the disconnection of power supply.
Embodiment 2: present embodiment concrete structure and operation principle are substantially the same manner as Example 1, and its difference is, copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 be 0.05mm, and the length in this space is 15mm.
Embodiment 3: present embodiment concrete structure and operation principle are substantially the same manner as Example 1, and its difference is, copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 be 0.15mm, and the length in this space is 28mm.
Embodiment 4: present embodiment concrete structure and operation principle are substantially the same manner as Example 1, and its difference is, copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 be 0.08mm, and the length in this space is 20mm.
Embodiment 5: present embodiment concrete structure and operation principle are substantially the same manner as Example 1, and its difference is, copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 be 0.02mm, and the length in this space is 13mm.
By the foregoing description as can be known, when copper sheathing 5 respectively and the space between the rotating shaft 7, switch base 2 more hour, be copper sheathing 5 respectively with rotating shaft 7, switch base 2 between cooperate tight more, the length in this space can be short more (must greater than 12.5mm, less than 30mm), the volume that is switch base 2 is more little, thereby has reduced the volume of whole flame-proof switch.Certainly, under some requires extremely rigorous environment, in order further to increase the fail safe of flame-proof switch, can guarantee copper sheathing 5 respectively and under the enough little situation in the space between the rotating shaft 7, switch base 2, the length that remains this space is grown (must greater than 12.5mm, less than 30mm).