JP2015081828A - Float sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a float sensor capable of maintaining slidability of a float to a guide shaft.SOLUTION: A float sensor FS comprises: a contact area where a guide shaft 10 and a float 20 contact between the guide shaft 10 and the float 20 when the float 20 slides along the guide shaft 10; and a non-contact area where the guide shaft 10 and the float 20 do not contact.

Description

  The present invention relates to a float sensor for measuring a water level of a liquid.

  2. Description of the Related Art As a float sensor that measures a liquid level, a sensor that includes a float that floats on a liquid and a guide shaft that is provided so as to penetrate the float is known (for example, see Patent Document 1 below). In the float sensor described in Patent Document 1, a reed switch is provided in the guide shaft, and a magnet is provided in the float. When the float is positioned at a portion of the guide shaft where the reed switch is provided, the contact of the reed switch is closed.

JP 2003-14524 A

  In the float sensor described in Patent Document 1, for example, when provided in a water tank so as to measure the water level of the water, the movement of the float gradually deteriorates, and the float may eventually stop. The inventor has discovered that.

  The present invention has been made in view of such problems, and an object thereof is to provide a float sensor capable of maintaining the slidability of the float with respect to the guide shaft.

  In order to solve the above problems, a float sensor according to the present invention is a float sensor that measures the level of a liquid, and includes a float that floats on the liquid, and a guide shaft that is provided so as to penetrate the float. Yes. In the float sensor according to the present invention, when the float slides along the guide shaft, the contact region where the guide shaft and the float contact between the guide shaft and the float does not contact the guide shaft and the float. And a non-contact area.

  In the present invention, since the contact area where the guide shaft and the float contact is provided between the guide shaft and the float, the float slides while contacting the guide shaft even though the non-contact area is provided. The float can be moved according to the water level. Furthermore, since a non-contact area where the guide shaft and the float do not contact each other is provided between the guide shaft and the float, the surface tension generated when the liquid stays on the upper surface and the lower surface of the float is prevented. As a result, the liquid does not stay on the upper and lower surfaces of the float. When the liquid is water, if the liquid stays on the upper surface or the lower surface of the float, calcium carbonate is precipitated, the precipitate becomes an obstruction factor, and the movement of the float becomes worse, and eventually the float does not move. In the present invention, water that causes calcium carbonate precipitation is prevented from remaining on the upper and lower surfaces of the float, so that it is possible to suppress the precipitation of calcium carbonate and hindering the movement of the float.

  In the float sensor according to the present invention, it is also preferable that the contact area and the non-contact area are alternately provided in the circumferential direction of the guide shaft.

  In this preferred embodiment, the contact area and the non-contact area are alternately provided, so that the float and the guide shaft can be in contact with each other in a well-balanced manner, and the effect of suppressing the surface tension of the liquid can be well-balanced over the entire circumference. Can do.

  In the float sensor according to the present invention, it is also preferable that the non-contact area is longer than the contact area along the circumferential direction of the guide shaft.

  In this preferable aspect, since the non-contact area is longer than the contact area, the effect of suppressing the surface tension of the liquid can be maximized.

  In the float sensor according to the present invention, the contact region and the non-contact region are preferably formed by providing at least one of a convex portion and a concave portion on at least one of the float and the guide shaft.

  In this preferred embodiment, the contact region and the non-contact region are formed by providing at least one of the convex portion and the concave portion on at least one of the float and the guide shaft, so that at least one of the convex portion and the concave portion is simply provided. By this method, the contact area and the non-contact area can be reliably formed.

  In the float sensor according to the present invention, it is also preferable that at least one of a convex portion and a concave portion is provided on the float.

  In this preferred embodiment, since at least one of the convex portion and the concave portion is formed on the float, the length of the convex portion and the concave portion can be shortened as compared with the case where the convex portion and the concave portion are provided on the guide shaft side. Thus, the contact area and the non-contact area can be provided more simply.

  In the float sensor according to the present invention, it is also preferable that at least one of a convex portion and a concave portion is provided in at least one of the vicinity of the upper surface and the vicinity of the lower surface of the float.

  In this preferable aspect, since at least one of the convex portion and the concave portion is provided in at least one of the vicinity of the upper surface and the lower surface of the float, the non-contact region can be reliably formed on at least one of the upper surface and the lower surface of the float. .

  ADVANTAGE OF THE INVENTION According to this invention, the float sensor which can maintain the slidability of the float with respect to a guide shaft can be provided.

It is the schematic which shows the float sensor which concerns on embodiment of this invention. It is a figure which shows the state which provided the convex part and the recessed part in the float shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  A float sensor according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing the float sensor FS. The float sensor FS includes a guide shaft 10 and a float 20. The float sensor FS is used by placing at least the guide shaft 10 and the float 20 in a tank in which a liquid to be measured is stored.

  The guide shaft 10 is provided with an upper stopper 101 and a lower stopper 102. A guide shaft 10 is passed through the float 20, and the float 20 moves up and down between an upper stopper 101 and a lower stopper 102. The float 20 is configured as a hollow member so as to float on the liquid to be measured. Accordingly, the float 20 moves up and down between the upper stopper 101 and the lower stopper 102 in accordance with the increase or decrease of the liquid to be measured.

  A reed switch (not shown) is provided inside the guide shaft 10. On the other hand, the float 20 is provided with a magnet. When the float 20 is positioned at a height where the reed switch of the guide shaft 10 is provided, the reed switch is closed and an electric signal is generated, and it can be detected that the float 20 is positioned at a predetermined height.

  When the level of a liquid such as water is measured with such a float sensor FS, an event occurs in which the float 20 becomes difficult to move or the float 20 is fixed. The present inventor considered that one of the causes of hindering the movement of the float 20 is that liquid such as water continuously stays between the guide shaft 10 and the float 20. If it is water, if it stays between the guide shaft 10 and the float 20, it will dry, calcium carbonate will precipitate, and the movement of the float 20 will be inhibited.

  Therefore, in the present embodiment, the float 20 is devised so that the float 20 does not adhere to the guide shaft 10. The device will be described with reference to FIG. FIG. 2 is a diagram illustrating a state in which convex portions and concave portions are provided in the float illustrated in FIG. 1, and is a diagram illustrating a state in which the upper surface 201 side of the float 20 is viewed from above.

  As shown in FIG. 2, the float 20 is provided with an inner cylindrical portion 203. The inner cylindrical portion 203 penetrates the float 20 so as to reach the lower surface 202 from the upper surface 201 of the float 20. A hollow portion 203 c is provided on the center side of the inner cylindrical portion 203. The hollow portion 203c has a substantially cylindrical space into which the guide shaft 10 is inserted.

  At the upper end of the inner cylindrical portion 203, convex portions 203a and concave portions 203b are alternately provided along the outer periphery of the upper end portion. The inner cylindrical portion 203 is a thin cylindrical member, and the convex portion 203a is formed by pushing the upper end inward at substantially equal intervals. Thus, if the convex parts 203a are formed at substantially equal intervals, the concave parts 203b are inevitably formed between the adjacent convex parts 203a. Therefore, the convex part 203a and the recessed part 203b are provided alternately.

  The convex portion 203a functions as a contact region of the present invention, and the concave portion 203b functions as a non-contact region of the present invention. Therefore, in the float sensor FS, when the float 20 slides along the guide shaft 10, a contact area between the guide shaft 10 and the float 20 where the guide shaft 10 and the float 20 come into contact with each other, and the guide shaft 10. And a non-contact area where the float 20 is not in contact with each other.

  Since the convex portion 203a that functions as a contact area where the guide shaft 10 and the float 20 are in contact is provided between the guide shaft 10 and the float 20, the float 20 is guided by the guide 20 even though a non-contact area is provided. It can slide while contacting the shaft 10, and the movement of the float 20 according to the water level can be ensured. Even when the projections 203a that are in contact with the guide shaft 10 are provided in a form very close to point contact as in the present embodiment, sliding of the float 20 can be achieved by providing a plurality of projections 203a and arranging them in a distributed manner. Can be ensured.

  Furthermore, since a recess 203b is provided between the guide shaft 10 and the float 20 as a non-contact area where the guide shaft 10 and the float 20 do not contact with each other, the liquid stays on the upper surface 201 and the lower surface 202 of the float 20 As a result, the liquid does not stay on the upper surface 201 and the lower surface 202 of the float 20. When the liquid is water, when the liquid stays on the upper surface 201 and the lower surface 202 of the float 20, calcium carbonate is precipitated, and the precipitate becomes an obstructive factor and the movement of the float 20 becomes worse. It will not move. In the present embodiment, water that causes calcium carbonate precipitation is prevented from staying on the upper surface 201 and the lower surface 202 of the float 20, so that the calcium carbonate is prevented from precipitating and inhibiting the movement of the float 20. be able to.

  In the present embodiment, the convex portion 203a that is a contact region and the non-contact region 203b are alternately arranged in the circumferential direction of the guide shaft 10 (the circumferential direction of the inner cylindrical portion 203 into which the guide shaft 10 of the float 20 is inserted). Is provided.

  Thus, since the convex part 203a as a contact area and the concave part 203b as a non-contact area are provided alternately, the float 20 and the guide shaft 10 can contact in a well-balanced manner, and the surface tension of the liquid is suppressed. The effect can also be produced with a good balance over the entire circumference.

  Further, in the present embodiment, the concave portion 203b that is a non-contact region is located along the circumferential direction of the guide shaft 10 (the circumferential direction of the inner cylindrical portion 203 into which the guide shaft 10 of the float 20 is inserted) rather than the convex portion 203a that is a contact region. It is provided to be long.

  As described above, since the concave portion 203b that forms the non-contact region is longer than the convex portion 203a that forms the contact region, the effect of suppressing the surface tension of the liquid can be maximized.

  Further, in this embodiment, the convex portion 203a that forms the contact region and the concave portion 203b that forms the non-contact region are provided only in the float 20, but even if provided in the guide shaft 10, the surface tension suppressing effect is similarly obtained. Demonstrate. Thus, the contact region and the non-contact region can be reliably formed by a simple method of providing at least one of the convex portion 203a and the concave portion 203b on at least one of the float 20 and the guide shaft 10.

  In the present embodiment, the float 20 is provided with a convex portion 203a and a concave portion 203b. Thus, since the convex part 203a and the recessed part 203b are formed in the float 20, the convex part 203a and the recessed part 203b also move up and down according to the vertical movement of the float 20, and a convex part and a recessed part are provided in the guide shaft 10 side. Compared to the above, the length of the protrusions and the recesses can be shortened, and the contact area and the non-contact area can be more easily provided.

  In the present embodiment, the convex portion 203 a and the concave portion 203 b are provided in the vicinity of the upper surface 201 and the lower surface 202 of the float 20. Thus, since the convex part 203a and the recessed part 203b are provided in the vicinity of the upper surface 201 and the lower surface 202 of the float 20, the non-contact area | region can be reliably formed in the upper surface 201 and the lower surface 202 of the float 20. FIG.

FS Float sensor 10 Guide shaft 101 Upper stopper 102 Lower stopper 20 Float 201 Upper surface 202 Lower surface 203 Inner cylindrical portion 203a Convex portion 203b Concave portion 203c Hollow portion

Claims (6)

A float sensor that measures the liquid level,
A float floating in a liquid,
A guide shaft provided so as to penetrate the float,
When the float slides along the guide shaft, a contact region where the guide shaft and the float are in contact with each other and the guide shaft and the float are not in contact between the guide shaft and the float. A float sensor comprising a non-contact region.   The float sensor according to claim 1, wherein the contact area and the non-contact area are alternately provided in a circumferential direction of the guide shaft.   2. The float sensor according to claim 1, wherein the non-contact area is longer than the contact area along a circumferential direction of the guide shaft.   The contact region and the non-contact region are formed by providing at least one of a convex portion and a concave portion on at least one of the float and the guide shaft. The float sensor according to the item.   The float sensor according to claim 4, wherein at least one of the convex portion and the concave portion is provided on the float.   The float sensor according to claim 5, wherein at least one of the convex portion and the concave portion is provided in at least one of the vicinity of the upper surface and the vicinity of the lower surface of the float.

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