JP3001519U - Liquid level detection switch - Google Patents

Abstract

(57) [Abstract] [Purpose] As a sealing member that prevents contamination due to spillage and seals the lead wire extraction portion, one having a simple structure and that can be easily arranged is used. [Structure] The lead wire lead-out portion 21 of the stem 2 is composed of a small-diameter passage portion 22 that communicates with a housing portion of the magnetic detection element and a large-diameter groove portion 23 that opens to one end surface 24 of the stem 2. As the sealing member 3 that seals the lead wire take-out portion 21, an elastic plug 31 that can be fitted into the small-diameter passage portion 22 and a holding plate 32 that snap-fits into the large-diameter groove portion 23 are used. After disposing the elastic plug 31 in the lead wire take-out portion 21,
Since it is only necessary to dispose the pressing plate 32 by snap-fitting it, the liquid level detection switch 1 can be easily manufactured.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquid level detection switch using a magnetic detection element, and more particularly to a liquid level detection switch with an improved sealing structure of a lead wire extraction part.

[0002]

[Prior art]

 Conventionally, a liquid level detection switch has been used as a device for measuring the liquid level such as the upper limit or the lower limit of the liquid level, which consists of a stem with a built-in magnetic detection element such as a reed switch and a float with a built-in magnet. ing. That is, when the float moves up and down with a change in liquid level, the magnetic force from the magnet changes, the reed switch etc. is turned on and off, and the signal is taken out to the external device through the lead wire. In the present specification, the magnetic detection element includes a magnetoelectric conversion element such as a Hall element in addition to the lead switch.

[0003]

[Problems to be solved by the device]

 Since the liquid level detection switch is installed in a liquid or vapor atmosphere, it is necessary to pay attention to the hermeticity of the part from which the lead wire is taken out so that the liquid does not enter the stem of the liquid level detection switch. is there. The lead wire lead-out portion 61 is usually a small-diameter passage portion 61a communicating with an accommodating portion (not shown) accommodating the magnetic sensing element and one end surface side of the stem 60, as shown in FIG. And a large-diameter groove portion 61b opening at Therefore, conventionally, a rubber plug 62 having a lead wire passage hole 62a formed therein is fitted to the end of the small diameter passage portion 61a of the lead wire lead-out portion 61, and then a resin molding material 63 is placed in the large diameter groove portion 61b. It was arranged.

However, when the resin mold material 63 requires a heating step to cure, it takes time to heat and cure, or when the resin mold material 63 is a liquid material, stains may occur due to spillage outside the large-diameter groove portion 61b. was there. Further, before filling the large-diameter groove portion 61b with the resin molding material 63, it is necessary to perform stirring, mixing of two liquids, and the like, which complicates the manufacturing process of the entire liquid level detection switch and takes a lot of working time.

The present invention has been made in order to solve the above problems, and can prevent contamination due to spills without using a resin molding material, and can be used as a simple sealing member for sealing the lead wire extraction portion. An object of the present invention is to provide a liquid level detection switch having a structure and that can be easily arranged.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the liquid level detection switch of the present invention has a magnet having a built-in magnetic detection element and a stem having a lead wire extraction portion, and a magnet built in a float arranged around the stem. In the liquid level detection switch in which the magnetic detection element is turned on / off by the magnetic force of, the lead wire lead-out portion of the stem has a small-diameter passage portion communicating with the housing portion of the magnetic detection element and a large-diameter groove portion opened at one end surface of the stem. The sealing member for sealing the lead wire lead-out portion is composed of an elastic plug formed so that it can be fitted into the small-diameter passage portion and a holding plate that snap-fits into the large-diameter groove portion. Is characterized by.

[0007]

【Example】

 Hereinafter, the present invention will be described in more detail with reference to an embodiment shown in the drawings. In the figure, 1 is a liquid level detection switch of this embodiment, 2 is a stem, 3 is a sealing member, and 4 is a lead wire.

Inside the stem 2, there is formed a storage part for arranging a magnetic detection element such as a reed switch (not shown), and a lead wire extraction part 21 communicating with the storage part. The lead wire take-out portion 21 is further engraved so that one end thereof communicates with the storage portion, and the other end 22a of the small diameter passage portion 22 is open at the one end face 24 side of the stem 2. The large-diameter groove portion 23 is formed.

The sealing member 3 includes an elastic plug 31 and a pressing plate 32. The elastic plug 31 is made of rubber, elastomer, or the like, and has a diameter such that the outer peripheral surface of the small-diameter passage portion 22 can fit closely. Further, a through hole 31a for inserting the lead wire 4 is provided near the substantially central portion.

As shown in FIGS. 1 to 5, the holding plate 32 is formed in a substantially circular plane shape having a size substantially the same as the diameter of the large-diameter groove portion 23 of the lead wire take-out portion 21. 23, it is so-called snap fit. Reference numeral 32a is an engagement piece that engages with the engagement groove 23a formed on the inner peripheral edge of the large-diameter groove portion 23 when snap-fitting. Further, the holding plate 32 has a notch 32b which is deeply carved from the peripheral edge to the vicinity of the central portion. The cutout portion 32b functions as a lead wire insertion portion for passing the lead wire 4 therethrough. The holding plate 32 is made of a resin such as polyacetal or a plate made of a metal, since the holding plate 32 is snap-fitted and therefore slightly distorted during fitting.

The liquid level detection switch 1 of this embodiment is manufactured as follows. First, a reed switch, for example, is provided as a magnetic detection element in the storage portion in the stem 2. One end 41 of the lead wire 4 is connected to the lead piece 5 of the reed switch. Next, the sealing member 3 is arranged. First, the lead wire 4 is passed through the through hole 31a of the elastic plug 31 and then the other end 22 of the small diameter passage portion 22 formed in the stem 2. Fit a. Next, the holding plate 32 is slightly distorted, and the engaging piece 32a is inserted into the engaging groove 23a of the large-diameter groove portion 23 by passing the lead wire 4 passing through the through hole 31a of the elastic plug 31 into the notch portion 32b. The large-diameter groove portion 23 is snap-fitted and fitted so as to be engaged. As a result, the liquid level detection switch 1 of this embodiment can be manufactured.

[0012]

[Effect of device]

 As described above, according to the liquid level detection switch of the present invention, since the sealing member is composed of the elastic plug and the pressing plate that snap-fits into the large diameter groove of the stem, it is used. , Easy to manufacture. In particular, unlike the case of using the conventional resin molding material, the time for drying and curing is not required, so that the manufacturing process and the working time can be shortened. Furthermore, since no resin mold material is used, there is no stain due to spills that occur when filling the resin mold material, and there is no inconvenience in appearance.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of an embodiment of a liquid level detection switch according to the present invention.

FIG. 2 is a cross-sectional view of a part of the liquid level detection switch of the embodiment viewed from an angle different from FIG.

FIG. 3 is a perspective view showing a holding plate used in the embodiment.

FIG. 4 is a plan view showing a holding plate used in the same example.

FIG. 5 is a bottom view showing a holding plate used in the example.

FIG. 6 is a sectional view showing a part of a conventional liquid level detection switch.

[Explanation of symbols]

 1 Liquid level detection switch 2 Stem 21 Lead wire extraction part 22 Small diameter passage part 23 Large diameter groove part 3 Sealing member 31 Elastic plug 32 Presser plate 4 Lead wire

Claims (1)

[Scope of utility model registration request] 1. An ON / OFF operation of a magnetic detection element, which has a stem having a lead wire extraction portion, and a magnetic force of a magnet incorporated in a float arranged around the stem, turns the magnetic detection element on and off. In the liquid level detection switch, the lead wire lead-out portion of the stem is composed of a small diameter passage portion communicating with the storage portion of the magnetic detection element and a large diameter groove portion opened at one end surface of the stem, and the lead wire lead-out portion is sealed. A liquid level detecting switch, wherein a sealing member for stopping comprises an elastic stopper formed so as to be fitted into a small diameter passage portion and a holding plate snap-fitted to the large diameter groove portion.