JPS59171802A - Detecting device for moving body - Google Patents

Abstract

PURPOSE:To enable the detection of a moving body without fitting a permanent magnet to a body to be detected, by providing the moving body having a part to be detected which is prepared by applying ferromagnetic surface treatment to a non-magnetic body, and a magnetic sensor detecting the quantity of movement of the part to be detected or the presence of the movement thereof. CONSTITUTION:An inlet 3 and an outlet 4 of a flow channel 2 are formed in a casing 1. Fixed vanes 5 give a turning movement to a fluid flowing in the direction of an arrow. A spherical body 6 is located in a free state in the flow channel 2 in the rear of the fixed vanes 5, and is moved round in the direction vertical to the flow in the flow channel by the turning flow of the fluid. The spherical body 6 is formed of resin or the like, and the surface thereof is subjected to ferromagnetic surface treatment, whereby a part to be detected is formed. An outflow preventing body 7 serves to receive the spherical body 6 moving round. A magnetic sensor 8 is fixed, together with a permanent magnet 9 giving a magnetic field thereto, to the casing 1 by a fixture 10. A control circuit 11 processes a signal from the magnetic sensor 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a movement detecting device for a moving body, such as detecting the rotational speed of a motor or a rotary flow rate sensor.

Conventional configurations and their problems Conventionally, as a method for detecting the amount of movement and the presence or absence of movement of a moving object, such as detecting the rotational speed of a fan or pump, a permanent magnet is attached to the surface of the detection part of the moving object, and a Hall element or magnetic There is a method of detecting by bringing a resistive element close to each other, or a method of detecting a detecting part made of a ferromagnetic material such as iron using a magnetoresistive element equipped with a bias magnet. An example thereof will be explained in FIG.

The figure shows a vane wheel type flow sensor.Fluid flows from the direction of the arrow and rotates the impeller 101, whose rotation speed is proportional to the flow rate.
02 and detection by the magnetoresistive element 103 provided outside the flow path, the flow rate is detected by pulses and calculated by a control circuit (not shown) to measure the flow rate. In this case, as mentioned above, it is necessary to attach a magnet to the blade, the installation must be done so that the magnet does not come off, foreign matter such as iron powder in the fluid can easily adhere to the blade and cause malfunction, and the blade is made of plastic or other lightweight materials. There are drawbacks to attaching permanent magnets to a moving body, such as the material being attached to the entire magnet, which increases the weight and reduces the sensitivity flow rate. On the other hand, to detect the rotation speed of gears, etc., in addition to the method of detecting by attaching a magnet to the gear side, there is also a method of detecting the rotation speed by attaching a bias magnet to the gear side.
A commonly used method is to detect the unevenness of a gear made of a highly polished metal such as iron using a magnetoresistive element placed close to it, but in this case, only ferromagnetic metals can be detected, making it difficult for practical applications. The range was extremely narrow.

Purpose of the Invention The present invention eliminates such conventional problems, and is capable of detecting a moving object without attaching a permanent magnet to the object to be detected, which is the moving side, and without any particular limitations on the material of the object to be detected. The aim is to provide a device that enables all

Structure of the Invention In order to achieve this object, the present invention provides a moving body having a detected part made of a non-magnetic material subjected to ferromagnetic surface treatment, and a magnetic sensor that detects the amount of movement or the presence or absence of movement of the detected part. , is equipped with a control circuit that processes signals from the magnetic sensor. This configuration has the effect that the amount of movement and the presence or absence of movement of the moving object can be detected by the magnetic sensor.

DESCRIPTION OF EMBODIMENTS Hereinafter, an example in which the moving body detection device of the present invention is implemented in a flow sensor will be described with reference to FIGS. 2 and 3. In Figure 2,
1 - Casing of flow path 2 of flowmeter sensor, 3 is its inlet, 4 is its outlet. Reference numeral 5 denotes a fixture that gives a swirling flow to the fluid flowing in the direction of the arrow, and is fixed to the casing 1 by press fitting or the like so that it does not rotate due to the flow of the fluid. Reference numeral 6 denotes a sphere (moving body) that exists in a free state in the flow path 2 downstream of the fixed blade 5 and rotates in the flow path in a direction perpendicular to the flow due to the swirling flow of the fluid.
The spherical body 6 is made of a light material such as resin, and its surface is subjected to a ferromagnetic surface treatment such as iron plating or iron-nickel alloy plating, thereby forming the detected portion. It is a spill prevention body for seven spheres 6, and serves as a circular receiver for the spheres 6. Reference numeral 8 denotes a magnetoresistive element (magnetic sensor), which is located outside the flow path near the circumferential circuit of the sphere 6, and is fixed to the casing 1 with a fixture 10 together with a permanent magnet 9 that applies a magnetic field to the magnetoresistive element 8 in all directions. 1.1 is a Hi control circuit that processes the iris from the magnetoresistive element 1Q.

Next, the operation will be explained. Fluid comes out from person 1]3 [1
4, the fixed blade 5 creates a swirling flow, and the swirling flow causes the sphere 6 to revolve within the flow path.

Since the number of revolutions per revolution is proportional to the flow rate, the number of revolutions is detected by the magnetoresistive element 8 and calculated by the lt control circuit 11 to obtain the number of revolutions. The direction of the magnetic flux from the permanent magnet 9 acting on the magnetoresistive element 8 changes as the ferromagnetic sphere 6 approaches, and the magnetoresistive element 8 detects this change in a pulsed manner. Become. The flow rate detected by the control circuit 11 is displayed as an instantaneous diversion, or when it is incorporated into a machine as a flow rate sensor, it is used as a signal source for controlling the machine. In addition, since the sphere 6 is made of plated resin, it is easy to use as a moving object.
Since it can be operated from a low flow rate, the flow rate sensitivity is improved, the kinetic energy is small, and the noise accompanying circulation is also small.

Fig. 3-1 is an embodiment of a flow rate sensor of the flow wing type. 12 is a case of the flow path, 13 is a train (moving body) that rotates according to the flow rate, 14 is its rotation axis, and 15 is a blade wheel 1
A rotation speed detection sensor (magnetic sensor) consisting of a magnetic sensor that detects the rotation of the blade, and is fixed to the casing 12 outside the flow path close to the blade. The impeller 13 is made of resin, and the surface VC is subjected to the above-mentioned ferromagnetic surface treatment to constitute a detected portion. The basic example of the operation in this case is the same as that shown in Fig. 2, in which the impeller 13 rotates in response to the diversion of fluid from the direction of the arrow, and the rotational speed of the magnetic material as the detected part is detected. It is detected by the sensor 15 and processed by a control circuit (not shown). In the case of this configuration as well, the effect that the sensitive flow h1- is small is obtained as in the previous embodiment. In addition to applying ferromagnetic curved surface treatment to the blade wheel 13 on the entire surface, it is also possible to detect it by applying it only to the vicinity of the tip of the blade. It is easy to spread the word by force.

Next, FIG. 4 shows an example in which the present invention is implemented in a device for measuring the rotational speed of a gear. In Figure 4, 16 is a motor, 1
γ is a shaft, 18 is a gear (moving body), and a magnetic resistance element 20 (magnetic sensor) having a bias magnet 19 is provided adjacent to the gear 18. The gear 18 is made of a non-magnetic metal or resin 4J material, and its surface is subjected to a ferromagnetic surface treatment. In this configuration, the pulse output at the peaks and valleys of the gear 18 is (111) of the element 20.
The number of rotations is determined by the number of revolutions U' through a circuit (not shown). Conventionally, gears had to be made of ferromagnetic metal materials, but in this embodiment, gears can be made of non-magnetic metals or resin materials, and are not particularly limited to criminal charges. Has full effect.

Effects of the Invention As described above, according to the moving object detection device of the present invention, the test object U'' portion of the moving object is subjected to ferromagnetic surface treatment, and the amount of movement and movement can be determined without attaching a magnet to the moving side. It is possible to detect the presence or absence, and the following effects can be obtained.

(1) The structure of the present invention is suitable for cases where it is difficult to attach a magnet to a moving object or where the environment in which the magnet is used is not suitable, such as when used underwater. There is no need to consider the structure of the support 4-1r film, and problems associated with mounting the permanent magnet on the moving side do not occur.

(2) The moving body to be subjected to the ferromagnetic surface treatment, which will be the part to be detected, is not limited to its location, shape, and size, but also to its material length. The material may be made of a resin material that has not been used in the past. In other words, the presence or absence of movement or the amount of movement of a moving object can be detected simply by surface-treating a part of the moving object or by attaching surface-treated resin parts to the moving object. wide.

(3) In a configuration in which a magnet is not attached to the moving side, the detected part of the moving body was conventionally limited to ferromagnetic metal materials such as iron.
However, the present invention can be applied without the benefit of surface treatment.

(4) Compared to the case of installing foundation stones, it is superior in reliability and durability because only surface treatment is required.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional flow sensor of -18゜, Fig. 2 is a sectional view showing one embodiment of the moving object detection device of the present invention, and Fig. 3 is a sectional view showing another embodiment of the present invention. Figure, Figure 4 (2L)
(b) is a 5il 1 side view and a 1f side view showing still another embodiment of the present invention. 6゛°・° sphere (moving object), 13°... impeller (moving object), 18・°゛gear moving object), 8, 20 ... magnetic resistance - * f - < magnetic sensor), 15 ・Rotation speed detection sensor (magnetic sensor), 11゛ control circuit.

Claims (4)

[Claims] (1) A moving body having a detected part made of a non-magnetic material subjected to ferromagnetic surface treatment, a magnetic sensor that detects the amount of movement or the presence or absence of movement of the detected part, and a signal from the magnetic sensor that processes the signal. A moving object detection device consisting of a control circuit. (2) The moving body detection device according to claim 1, wherein the moving body is not a rotating body, and the rotating body rotates according to the fluid flow rate in the flow path. (3) The moving object detection device according to claim 2, wherein all of the non-magnetic rotating bodies made of resin molded articles are the detected parts. (4) The moving object detection device according to claim 1, wherein the ferromagnetic surface treatment is iron plating or iron-nickel alloy plating.