JPH0442756Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a leakage oil detection sensor.

(Prior art and problems) For example, in places such as gas stations that handle oil such as gasoline, diesel oil, and kerosene, when oil leaks occur, it is quickly detected and appropriate measures are taken. It is required that Leakage oil detection sensors for detecting such oil leakage have been known in the past with various structures, but all of them have the problem of complicated structures and high costs.

This invention was made in view of the above points, and its purpose is to provide a leakage oil detection sensor that has a simple structure and can be manufactured at low cost.

(Means for solving the problem) Therefore, the leaked oil detection sensor of this invention has a cylindrical sensor body with an inlet for leaking oil such as gasoline at the upper end and an outlet at the lower end. A magnet body with a through hole that communicates the inlet and outlet is attached, a magnetic fluid is held in this magnet body, a float is placed on this magnetic fluid, and the float is moved in the vertical direction. It is equipped with a detection means for detecting displacement.

The magnetic fluid is a fluid made by suspending ferromagnetic particles, such as magnetite particles, with a particle size of about 100 mm in an oil base solvent via a surfactant. These ferromagnetic particles are suspended in suspension by colliding with molecules in the base solvent that undergo random thermal motion, and are permanently prevented from agglomerating by the action of the stabilizer, which makes them magnetic. The fluid is a stable, homogeneous colloidal liquid. As is well known, this magnetic fluid has the property that its position can be controlled by the magnetic force of an external magnetic field.

(Function) In the leaked oil detection sensor with the above configuration, the leaked oil that flows in from the inlet of the sensor body descends inside the sensor body, dissolves the base solvent of the magnetic fluid held in the magnet, and together with this magnetic fluid. , it will flow out to the outlet via the through hole. As a result, the float placed on the magnetic fluid is displaced downward. Note that if the amount of leaked oil is relatively small, the volume of the magnetic fluid may increase as the leaked oil dissolves, but in this case, the float will be displaced upward. Leakage of oil is detected by detecting vertical displacement of the floating float as described above using the detection means.

(Example) Next, a specific example of the leakage oil detection sensor of this invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of this invention.
In the figure, reference numeral 1 denotes a sensor body, which has a cylindrical shape, with an opening at its upper end serving as an inlet 2 for leaking oil such as gasoline, and an opening at its lower end serving as an outlet 3 thereof. A disk-shaped permanent magnet 4 serving as a magnet body is fitted and attached to the inner peripheral portion of the sensor body 1. This permanent magnet 4 has a through hole 5 in its axial center that communicates the inlet 2 side and the outlet 3 side. The magnetic poles of each permanent magnet 4 may be arranged in either the thickness direction or the radial direction. A magnetic fluid 6 is held in this permanent magnet 4 . Preferably, the base solvent of the magnetic fluid 6 is one having a low evaporation rate, such as ester, mineral, or synthetic oil. A disk-shaped float 7 is placed on the upper surface of the magnetic fluid 6 . This float 7 has rod-shaped parts 8 and 9 extending upward and downward, respectively, at its axial center. On the other hand, a support frame 1 is provided on the outer periphery of the sensor body 1.
0 is attached to the support frame 10, and proximity switches 11 and 12 are supported by the support frame 10, which are opposed to the tips of the rod-shaped parts 8 and 9, respectively. That is, the proximity switches 11 and 12 are connected to the rod-shaped parts 8 and 9 of the float 7.
constitutes a detection means that is activated when the tip of the sensor approaches and outputs a detection signal to a display means (not shown). Although the float 7 is levitated by utilizing the characteristic that the specific gravity of the magnetic fluid 6 in the magnetic field increases, other characteristics may be utilized.

In the leaked oil detection sensor configured as described above, the leaked oil flowing from the inlet 2 of the sensor body 1 descends within the sensor body 1 and is dissolved in the magnetic fluid 6 held by the permanent magnet 4. This is because the base solvent constituting the magnetic fluid 6 and the leaked oil have a property of being soluble in each other. As this leaked oil dissolves, both the magnetic fluid 6 and the leaked oil
The outlet 3 passes through the through hole 5 against the magnetic force of the permanent magnet 4.
It will flow out to the side. As a result, the float 7 placed on the magnetic fluid 6 is displaced downward. As the float 7 is displaced, the tip of the lower rod-shaped portion 9 comes close to the lower proximity switch 12, and the proximity switch 12 is activated to indicate oil leakage on the display means. It is.

Furthermore, when the amount of leaked oil is relatively small, the volume of the magnetic fluid 6 may increase as the leaked oil dissolves, but in this case, the float 7 will be displaced upward, causing the upper rod-shaped The tip of the portion 8 comes close to the upper proximity switch 11, and the switch 11 is activated to display oil leakage on the display means in the same manner as described above.

That is, in the above case, the leaked oil is the magnetic fluid 6
When the float 7 placed on the magnetic fluid 6 undergoes some vertical displacement due to dissolution in the magnetic fluid 6, this is determined to be oil leakage.

As described above, the leakage oil detection sensor described above can accurately detect oil leakage, has an extremely simple structure, and can be manufactured at low cost.

Further, in the above embodiment, by using a base solvent of the magnetic fluid 6 with a low evaporation rate such as ester, mineral oil, or synthetic oil, it is possible to make the magnetic fluid 6 durable for long-term use. be.

FIG. 2 shows another embodiment of this invention. In this leakage oil detection sensor, the float 7a
has only a rod-shaped portion 14 extending downward, and is configured to detect displacement of the float 7a in the vertical direction based on the behavior of the rod-shaped portion 14. The other parts have the same configuration as those of the above-mentioned embodiment, so the same parts are given the same reference numerals and the explanation thereof will be omitted. In this embodiment as well, it is possible to achieve substantially the same effects as in the above embodiment.

The specific embodiment of the leakage oil detection sensor of this invention has been described above, but in this invention, the shapes of the sensor body 1, permanent magnet 4, floats 7, 7a, etc. can be changed as appropriate. . Also, regarding the through hole 5, if it has the function of communicating the inlet 2 side and the outlet 3 side of the sensor body 1 and causing the magnetic fluid 6 and leaked oil to flow from the inlet 2 side to the outlet 3 side, Its position, size, etc. can be changed as appropriate. Further, as the detection means, it is possible to employ various conventionally known means as long as the displacement of the float 7 in the vertical direction can be detected.

(Effects of the invention) As described above, since the leakage oil detection sensor of this invention has the above-mentioned configuration, it is possible to perform accurate operation, while having a simple structure and low cost. It can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the leakage oil detection sensor of this invention, and FIG. 2 is a sectional view showing another embodiment of this invention. 1...Sensor body, 2...Inlet, 3...Outlet,
4...Permanent magnet (magnet body), 5...Through hole, 6...
Magnetic fluid, 7, 7a... Float, 11, 12... Proximity switch (detection means).

Claims (1)

[Scope of utility model registration request] A magnet body equipped with a through hole communicating the inlet and outlet is attached to the inner circumference of a cylindrical sensor body having an inlet for leaked oil such as gasoline at the upper end and an outlet at the lower end, This magnet body holds a magnetic fluid, and a float is placed on this magnetic fluid.
A leakage oil detection sensor further comprising a detection means for detecting vertical displacement of the float.