JPH0332978Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a piezoelectric level sensor.
Is the level detection tube immersed in the liquid surface of the container?
A level sensor that detects the increase or decrease of liquid depending on whether it rises above the liquid level by changing the strength of the signal level, absorbs as much external vibration as possible transmitted from the container, etc., and at the same time It has a field of application that makes installation easy and robust.

(Prior Art) Piezoelectric level sensors are already known, but the structure for actively preventing the influence of external vibrations is technically insufficient.

(Problems to be Solved by the Invention) The problem is to add a structure to a piezoelectric level sensor having a conventional structure to prevent the effects of external vibration as much as possible and to facilitate installation.

(Means for solving the problem) The purpose of this invention is to solve the problem described in the previous section. In a level sensor in which a cable is inserted and fixed into the upper opening of the detection tube, and a lead wire pulled out from the cable is connected to the electrode of the piezoelectric vibrator, a vibration absorbing material is tightly attached to the outer periphery of the upper opening of the level detection tube. A synthetic resin mounting collar is formed in close contact with the outer periphery of the cable inserted from the upper opening of the level detection tube and the outer periphery of the upper opening and the vibration absorbing material.

A preferred embodiment of the present invention will now be described.

(Example) The attached drawings illustrate embodiments of the present invention, and Fig. 1 is a partially cutaway front view, Fig. 2 is a longitudinally sectional front view of the mounting collar and vibration absorbing material, and Fig. 3 shows the installation. FIG. 3 is a partially cutaway front view shown in FIG.

In the figure, 1 is a level detection tube with a thin metal plate 2 attached to the bottom, a piezoelectric vibrator 4 is bonded to the thin metal plate 2, and a cable 6 is connected to the upper part 3 of the level detection tube 1.
is inserted and fixed with two crimps 9, upper and lower, each having a hexagonal planar cross section. Further, lead wires 7 and 8 drawn out from the cable 6 are connected to electrodes 5a and 5b on the top surface of the piezoelectric vibrator 4, respectively.

Reference numeral 10 denotes a vibration absorbing material wrapped around the outer periphery of the upper opening portion 3, which is made of a heat-shrinkable silicone tube with a thickness of about 1.00 mm, and is brought into close contact with the material by shrink treatment, so that the caulking portion 9 is recessed. Reference numeral 11 denotes a mounting collar made of synthetic resin molding that surrounds the upper mouth portion 3 and a part of the cable 6 on the outer periphery of the vibration absorbing member 10, and is injection molded using polyethylene phthalate or polypropylene. Its thickness is
It has a diameter of about 2.00 mm and has a cylindrical shape with a smooth outer surface, and the inner surface in contact with the vibration absorbing plate 10 has an inner protrusion shape that roughly matches the shape of the recess of the caulking member 9.

The level sensor of the present invention has the vibration absorbing material 10 as the first
It protrudes downward as shown by the chain line in the figure, and after the mounting flange 11 is injection molded, the chain line portion is cut off.

As shown in FIG. 3, the level sensor of the present invention is constructed by passing the mounting collar 11 through a bushing member 23 screwed into a hole 22 of a container 21 filled with liquid inside an oil pan, etc. A union nut 26 is seated on the stepped surface of the diameter hole 24 via an O-ring 27, and is screwed onto a screw 25 provided on the outer periphery of the bushing member 23 that protrudes upward from the container 21. Attachment is performed by sandwiching the mounting collar 11 between the inner surfaces of.

(Function of the invention) As stated above, the present invention has a level detection tube 1.
A vibration absorbing material 10 is provided in close contact with the upper opening portion 3, and a synthetic resin mounting collar 11 is attached to the outer periphery of the cable 6 inserted from the upper opening of the level detection tube 1, and to the outer periphery of the upper opening and the vibration absorbing material 10. form a close contact. Therefore, even if the container etc. to which the level detection tube 1 is installed vibrates due to its proximity to an internal combustion engine, the level detection tube 1 can absorb the vibration due to the two layers of the mounting collar 11 and the vibration absorbing material 10. especially vibration absorbing material 1
The vibration absorbing effect of 0 extremely effectively prevents the level detection tube 1, cable 6, lead wires 7, 8, etc. from being affected by external vibrations and noise from entering the level detection signal.

(Effect of the invention) The present invention has the above-mentioned effect and prevents as much as possible the influence of external vibrations on the level detection elements such as the level detection tube 1, cable 6, lead wires 7 and 8, and piezoelectric vibrator 4. At the same time, the mounting collar 11 with the vibration absorbing material 10 tightly attached thereto has the effect of making the mounting to a container or the like simple and robust while producing a vibration prevention effect.

[Brief explanation of the drawing]

The attached drawings illustrate an embodiment of the present invention, and Fig. 1 is a partially cutaway front view, Fig. 2 is an enlarged front view taken longitudinally of the mounting collar and vibration absorbing material, and Fig. 3 is an illustration showing the installation. FIG. 1...Level detection tube, 2...Thin metal plate, 3...
Upper mouth part, 4... Piezoelectric vibrator, 5a, 5b... Electrode, 6... Cable, 7, 8... Lead wire, 10
...Vibration absorber, 11...Mounting collar.

Claims (1)

[Claim for Utility Model Registration] A cable is inserted and fixed into the upper opening of a level detection tube with a thin metal plate attached to the bottom and a piezoelectric vibrator mounted on the thin plate, and the cable is pulled out from within the level detection tube. In a level sensor in which a lead wire is connected to an electrode of the piezoelectric vibrator, a vibration absorbing material made of a heat-shrinkable silicone tube is provided in close contact with the outer periphery of the upper opening of the level detection tube, and A piezoelectric level sensor characterized in that a synthetic resin mounting collar is formed in close contact with the outer periphery of the inserted cable, the upper opening, and the outer periphery of the vibration absorbing material.