JPS598180Y2 - Head of temperature detection end - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a head of a temperature detection end that prevents the rotation of a screwed protective tube.

The head at the temperature detection end consists of a protective tube that houses the thermocouple or resistance temperature detector, and a connector that houses the connecting fittings, terminal board, etc. and connects the thermocouple or resistance temperature detector to the lead wire. is screwed onto the connector.

Incidentally, the head of the temperature detection end is used in various equipment for measuring temperature, and is often installed in a place where vibrations are severe.

If the head of the temperature detection end is installed in a place with strong vibrations,
Vibrations are transmitted to the head of the temperature detection end, causing problems such as the screwing of the protective tube loosening during use, and the protective tube being removed and unable to be used.

For this reason, rotation has been prevented using a lock nut that is screwed onto the outer circumferential surface of the protective tube so as to come into contact with the end surface of the connection part of the connector, or a set screw that is screwed inward onto the outer circumferential surface of the connector. .

However, even if a lock nut or set screw is used, it is not always sufficient to prevent rotation, and in particular, in the case of a flameproof explosion-proof temperature detection end head, not only one type of rotation prevention but also double rotation prevention is provided. is required.

Therefore, in view of the above-mentioned circumstances, this invention provides, in addition to the lock nut, a rotation preventing collar that restricts the rotation of the lock nut beyond a certain level.

Hereinafter, this invention will be described in detail based on specific embodiments shown in the accompanying drawings.

The protection tube 1 includes a nipple 2 or a sheath 3, and the protection tube 1 has a thermocouple or a resistance temperature detector at the tip (
A lock nut 4 having a hexagonal outer shape and a screw thread engraved on the outer circumferential surface of the proximal end of the protection tube 1 is screwed into the protective tube 1.
It is fixed by welding 5.

The connector 6 houses connection fittings, terminal plates, etc. for connecting the thermocouple or resistance temperature detector to the lead wire, and the connection part 7 with the protection tube 1 has a cylindrical shape and has a protection tube on its inner surface. A thread is carved to engage with the thread on the outer peripheral surface of the proximal end of No. 1,
An annular groove 9 with a semicircular cross section is provided at the lowest part of the inner surface of the connecting part 7 in order to arrange an O-ring 8 to maintain airtightness between the connecting part 7 and the outer surface of the protective tube 1. A circumferential engagement groove 10 is carved on the surface.

The anti-rotation collar 11 is a cylindrical body that is slightly longer than the connecting portion 7 of the connector, and the inner end thereof is connected to the lock nut 4.
It has a dodecagonal shape that fits into the hexagonal outer shape of the connector, and the other part is cylindrical, and the inner surface outside the end is set to have a slightly larger diameter than the connecting part 7 of the connector 6, and is designed to protect the outer peripheral surface of the connecting part of the connector. Matching groove 10
Screw holes 13 for locking screws 12 on the wall at positions corresponding to
to be engraved.

Note that if the rotation stopper collar 11 is manufactured by die-casting, the dodecagonal shape of the inner surface can be accurately and easily formed.

Note that the parts housed in the protective tube 1 and the connector 6 are not shown and omitted.

To assemble the head of the temperature detection end, first, screw the proximal end of the protective tube 1 to which the lock nut 4 is fixed and the O-ring 8 fitted into the inner surface of the connecting part 7 of the connector 6, and then insert the lock nut 4 into the connecting part. 7, the O-ring 8 is compressed and disposed between the outer peripheral surface of the protective tube 1, the annular groove 9, and the lock nut 4, and the O-ring 8 maintains an airtight state. is tightened with a lock nut 4.

Next, the rotation stopper collar 11 is fitted to the outer peripheral surface of the connecting portion 7 of the connector 6 and the outer peripheral surface of the lock nut 4.

At this time, since the inner end of the rotation stopper collar 11 is formed in a dodecagonal shape, it fits into the outer shape of the lock nut 4 by rotating by 30 degrees or less.

Also, connect the screw hole 13 of the rotation stopper collar 11 to the connector 6.
The anti-rotation collar 1 corresponds to the retaining groove 10 of the connecting part 7.
1 is fitted into the connecting portion 7, the circumferential groove width of the engagement groove 10 is set larger than that of the locking screw 12, so the screw hole 13 is arranged opposite to the engagement groove 10, and this Screw hole 13
When the locking screw 12 is screwed into the locking screw 12, the locking screw 12 will fit into the engagement groove 10.
inserted inside.

If the screw of the protection tube 1 becomes loose due to some reason and rotates due to the head of this temperature detection end, the fixed lock nut 4 will also rotate in the same way, causing the rotation stopper collar 11 to rotate. A locking screw 12 abuts against the circumferential end of the engagement groove 10 of the connector 1 to restrict further rotation, that is, loosening of the protective tube 1.

The amount of movement of the locking screw 12 in the engagement groove 10 should be an amount corresponding to half of a square, that is, about 15 degrees (in actual design, it is about 20 degrees with a margin), so the protection tube Even if 1 becomes loose, the thread pitch is 15/360 =
It is 1/24, and for example, if the pitch of the screw thread is 2 mm, it is as small as 0.08 mm.

This idea involves screwing the protective tube that houses the thermocouple or resistance temperature detector, as described above, into a connector that houses the connecting fittings, terminal board, etc., and connects the thermocouple or resistance temperature detector to the lead wire. At the head of the temperature detection end, a lock nut with a square outer shape is fixed to the outer circumferential surface of the protective tube screwed onto the connector so that it comes into contact with the end surface of the connecting section of the connector. A locking groove is carved in the circumferential direction, and a rotation preventing collar whose inner end is shaped into a polygonal corner than the outer corner of the lock nut is provided on the outer circumferential surface of the connecting portion of the connector and the outer circumferential surface of the lock nut. This is the head of the temperature sensing end, which is fitted into the retaining groove by screwing the locking screw inward to the wall surface of the locking collar at a position opposite to the locking groove of the connector. To reliably prevent rotation with only a slight loosening of a protective tube, and to provide it at a low cost.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional front view of the main parts of an embodiment of this invention;
Figure 2 is a bottom view taken along the line II-II in Figure 1, Figures 3 and 4 are other embodiments of this invention, Figure 3 is a front view using nipples in the protective tube, and Figure 4 is a It is a front view using a sheath for a protection tube. 1... Protection tube, 6... Connector, 4
....Lock nut, 7..Connection part of connector protection tube, 10..Engagement groove, 11..
... Rotating collar, 12 ... Locking screw.

Claims (1)

[Scope of utility model registration request] At the head of the temperature detection end, a protective tube 1 that houses a thermocouple or a resistance bulb is screwed onto a connector 6 that houses a connecting fitting, a terminal board, etc., and connects a thermocouple or a resistance bulb and a lead wire. A lock nut 4 having a square outer shape is fixed to the outer circumferential surface of the protective tube 1 screwed onto the connector 6 so as to come into contact with the end surface of the connecting portion 7 of the connector, and A locking collar 11 is formed with a locking groove 10 in the direction, and the inner end is shaped into a polygonal corner than the outer corner of the locknut 4. The locking screw 12 is screwed inward to the wall surface of the rotation stopper collar 11 at a position opposite to the locking groove 10 of the connector, and the locking screw 12 is fitted into the locking groove 10. Features a temperature sensing head.