JPS6246067Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a device for airtightly connecting a flexible wire to a limit switch.

For example, when connecting a flexible wire to a limit switch, etc., a joint attached to the end of the tube is screwed into the mounting screw hole of the limit switch. 51
No. 4 indicating No. 48025 (airtight connection device for fluid pipes)
As shown in the figure, fit an O-ring receiving fitting as shown in figure b, which is formed into an elastic annular body by notching one part of the annular shape, into the root of the nipple mounting spiral tube, and then forcibly fit the O-ring to ensure an airtight seal. Airtightness was achieved by screwing the screw tube into the limit switch mounting screw hole and pressing the O-ring. However, due to the expansion of the O-ring due to the tightening pressure, the notch of the receiving fitting opens and the airtightness tends to deteriorate. Furthermore, as shown in Fig. 2, the surface around the mounting screw hole in commonly used limit switches is extremely narrow in some areas due to shape constraints, making it insufficient as a seal seat. It is difficult to achieve complete airtightness, and electrical contacts are likely to fail due to intrusion of dust, oil, etc. from the outside.

Also, at the root of the male thread of the nipple mounting screw,
A structure in which a triangular notch groove is provided and an O-ring 8 is fitted therein is disclosed in Japanese Utility Model Application No. 53-52016, but this notch groove is provided over the entire width of the side end surface of the root. Since there is no stopper on the side end surface of the side end of the nut that will be screwed into the threaded part of this nipple, there is a high risk of the nut being screwed in excessively. There is a problem in that the O-ring loses its elasticity due to screwing and becomes sagging, making it unable to perform its sealing function.

Therefore, in this invention, a
A triangular receiving groove is formed and an O is fitted into this receiving groove.
In the case where the ring is compressed between the side end of the mounting body and the receiving groove to create an airtight seal, the ring is inserted into the side wall of the flange-like part of the nipple at a point about 1/3 deep from the outer periphery at a substantially right angle. A triangular notch is formed to form a receiving groove, and a stopper portion is attached to the outside of the receiving groove on this side wall 7.
When the O-ring is inserted into the receiving groove and the nipple is screwed onto the limit switch as a mounting body, the stopper portion contacts the side end of the limit switch 2 and the O-ring is inserted into the receiving groove and the limit switch seal seat. A flexible electric wire limit switch airtight device characterized by being held in an elastic airtight state between the It has been devised so that it can be done.

An embodiment of this invention will be described below with reference to the attached drawings. In Fig. 1, a mounting screw 1
is to be screwed into the joint mounting screw hole 3 of the limit switch 2, and the pipe on the opposite side of the mounting screw 1 is to be fitted with the mouth end of flexible electric wire piping, etc.; It has a flange-shaped part 5 which acts as a ring holding part, and the outer periphery of this flange-shaped part 5 is accompanied by a nut-shaped spiral part 6, which serves as a wrench engagement part during installation.

In the flange-shaped portion 5, a receiving groove 9 for the O-ring 10 is formed in the side wall 7 on the side of the limit switch 2 by cutting deeply into the side wall 7 from about 1/3 of the circumference of the flange-like portion 5 so as to have a substantially right triangular longitudinal section. A flat stopper portion S, which is substantially perpendicular to the longitudinal direction of the nipple 4, is formed on the side wall 7 on the outside of the receiving groove 9. or,
Since the O-ring receiving groove 9 is deeply cut out, a sufficient escape gap is provided for the O-ring 10 during tightening, and it functions effectively as the O-ring receiving groove. Therefore, when connecting the joint constructed in this manner to the mounting screw hole 3 of the limit switch 2, the O-ring 10 of an appropriate size and shape is forcibly fitted into the mounting screw tube 1 and fitted into the receiving groove 9 as described above. This is screwed into the mounting screw hole 3 of the limit switch 2 and tightened. At this time, the receiving groove 9
The O-ring 10 fitted here is pressed by the receiving groove 9 and is restrained from expanding and expanding. Then, the O-ring 10 comes into contact with the seal seat 11 around the limit switch mounting screw hole 3, and the stopper portion S of the nipple 4 comes into contact with the outer part of the seal seat 11 as shown in FIG. Since it comes into contact with the contact portion 12, the O-ring 10 is clamped by the right triangular inclined surface and cylindrical surface of the receiving groove 9, and the seal seat 11 of the limit switch 2 in these three directions. In addition, because the O-ring 10 is always clamped with a constant force due to the contact between the stopper portion S and the seal seat 11, there is a risk that the O-ring 10 may be crushed by excessive pressure and become bent. Therefore, the O-ring 10 can always be in contact with the above three surfaces with a constant elasticity, and the stopper part S and the side end part 12 of the nipple 4 and the limit switch 2 and the mutually threaded parts are airtight. This will ensure a sufficient amount of

In particular, the stopper part S and the stopper seat 1
The contact action of 1 sufficiently prevents over-tightening which is seen in the conventional products mentioned above. According to this invention, the O-ring 10 can be tightened for a long period of time without becoming sagging. Therefore, a good sealing effect can be maintained. Also, this receiving groove 9
Since it forms a part of the nipple 4, it has higher strength than the case of a receiving metal fitting, and it does not expand and impair airtightness, and since you can simply insert an O-ring, there is no risk of loss of the receiving metal powder, etc. There are no breakdowns and it is easy to handle.

Furthermore, the receiving groove of this invention has a rational shape and is easy to machine. That is, as shown in FIG. 3a, if the machining tool 13 is mounted obliquely to the tube axis direction and the shape of the cutting edge is used to cut a groove with a triangular cross section, machining can be easily performed and can be performed simultaneously with thread cutting. It is extremely efficient. Incidentally, a receiving groove as shown in FIG. 3 b or c is also considered, but in the case of a rectangular cross-section receiving groove 14 having an inner diameter larger than the outer diameter of the screw tube part as shown in FIG. Patsukinza 11
Due to the narrow diameter of the O-ring, the diameter of the O-ring used is too large, making it impossible to maintain airtight contact.Also, the rectangular cross-section receiving groove 15 whose inner diameter is the smooth surface 8 on the outer periphery of the tube as shown in Fig. c is not suitable in terms of shape. However, in actual machining, the screw threads get in the way and machining is impossible.

As explained above, the present invention is simple because the O-ring receiving metal part is reduced, and it is possible to maintain airtightness even when connecting to a narrow seal seat, and furthermore, the processing is extremely simple. It has excellent practical value.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the main part of the embodiment of the airtight pipe joint of the present invention in a cutaway section, Fig. 2 is a perspective view of the limit switch, Fig. 3 is a sectional view of the main part explaining the receiving groove processing method, Fig. 4a is a plan view showing a main part of a conventional pipe joint in a cutaway section, and Fig. 4b is a plan view of an O-ring receiving fitting of the pipe joint. Description of symbols, 1...Mounting screw tube, 2...Limit switch, 3...Mounting screw hole, 4...Nipple, 5
...flange-shaped part, 7 ... side wall, 8 ... pipe outer periphery smooth surface, 9 ... receiving groove, 10 ... O-ring, 11 ...
Pocket seat, 12... side end, S... stopper part.

Claims (1)

[Scope of utility model registration request] A triangular receiving groove is formed on the side wall of the flange-like part of the nipple opposite to the side that is screwed into the mounting body, and the O-ring fitted into this receiving groove is pressed between the side end of the mounting body and the receiving groove. In a device designed to provide airtightness, a receiving groove 9 is formed in the side wall 7 of the flange-like portion 5 of the nipple 4 by forming a receiving groove 9 in the shape of a right triangle deep from about 1/3 of the outer circumferential edge of the side wall 7. A stopper portion S is provided on the side wall 7 outside the groove 9, and when the O-ring 10 is fitted into the receiving groove 9 and the nipple 4 is screwed onto the limit switch 2 as a mounting body, the stopper portion S is attached to the limit switch 2. side end 1
2, the O-ring 10 is held in an elastic airtight state between the receiving groove 9 and the seal seat 11 of the limit switch 2.