JPS6249565B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a flow rate and flow rate change rate detection device used in a hydraulic servomechanism such as a robot, a steam turbine, and a hydraulic elevator.

[Prior art]

BACKGROUND ART Conventionally, there has been a demand for the development of a detection device for flow rate Q and flow rate change rate Q in hydraulic servomechanisms such as robots, steam turbines, and hydraulic elevators. Therefore, in order to satisfy this demand, a mover with a permanent magnet installed inside the tube is moved by differential pressure, and its displacement and velocity are detected by a detection coil wound around the outer circumferential surface of the tube, and this is equivalently calculated as the flow rate. We have developed a detection device that determines the rate of change in flow rate.

According to this detection device, it is possible to simultaneously detect the flow rate and the rate of change in flow rate, which was previously impossible, but since it requires the use of a mover with a permanent magnet, it has the drawback of lacking quick response. It was hot. That is, when the change is severe, the response of the movable element is delayed due to the large mass of the movable element, so there is a problem that the sensor is not sufficient as a sensor for a hydraulic servomechanism that requires a quick response.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a flow rate and flow rate change rate detection device that has faster responsiveness.

[Summary of the invention]

In order to achieve the above object, the present invention detects the flow rate and flow rate change rate of the fluid flowing inside the pipe by detecting the displacement and speed of a movable body slidably provided inside the pipe made of a non-magnetic material. A flow rate and flow rate change rate detection device includes a permanent magnet and a primary excitation coil provided on the outer circumferential surface of a tube, a pair of end plates attached to the inner wall of the tube and having an opening, and integrally coupled with the end plate. The movable body includes a rod and a fixed body having a first annular protrusion provided in the middle of the rod, and a movable body includes a secondary detection coil provided to face the permanent magnet and an inner side of the secondary detection coil. a second annular protrusion, a guide portion that loosely fits into the rod, and a pair of collar portions having an opening;
It consists of a cylindrical part that is integrally connected to the collar part and contains a second annular projection, and is characterized by being positioned by a spring.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a pipe made of a non-magnetic material, 2 is a pair of end plates 3a, 3b attached to the inner wall of the pipe 1, each having openings 4a, 4b, and both end plates 3a, 3.
Rod 5 integrally connected to b, and this rod 5
This is a fixed body consisting of an annular protrusion 6 with a diamond-shaped cross section provided in the middle of the annular protrusion 6.

Reference numeral 7 indicates guide portions 8a, 8 that fit loosely into the rod 5.
a pair of collar portions 10a, 10b having openings 9a, 9b, respectively, and both collar portions 10a,
10b, a cylindrical part 11 which is integrally connected with the cylindrical part 11 and houses the annular projection 6, and an annular projection 12 which is attached to the inner and outer peripheral surfaces of the cylindrical part 11, respectively.
and a movable body consisting of a secondary detection coil 13,
This movable body 7 is provided so as to be movable in the axial direction within the tube 1.

14a and 14b are guide parts 8a and 8 of the movable body 7
The springs 14a and 14b are interposed between the end plates 3a and 3b of the fixed body 2, and the elasticity of the springs 14a and 14b holds the protrusions 6 and 12 facing each other in the neutral position. . 15, 16
A permanent magnet and a primary excitation coil are mounted on the outer peripheral surface of the tube 1 made of non-magnetic material so as to face the secondary detection coil 13 inside the tube 1. 17 is a detection line connecting the secondary detection coil 13 and a detector (not shown).

Next, the operation of this embodiment configured as described above will be explained.

When fluid flows through the pipe 1, the annular projection 12 of the movable body 7 moves relative to the annular projection 6 of the fixed body 2 due to the differential pressure between the upstream side and the downstream side. Therefore, since the protrusion 12 moves relative to the permanent magnet 15, the reactance changes and a voltage proportional to the moving speed of the secondary detection coil 13 is generated, so that the voltage of the secondary detection coil 13 itself changes. The amount of movement and the speed of movement can be detected via the detection line 17 by a detector (not shown).

In this case, the annular protrusion 12 of the movable body 7 and the fixed body 2
By forming the protrusions 12 and 6 so that their displacement with the annular protrusion 6 is proportional to the flow rate Q, it is possible to detect the flow rate Q and the rate of change in flow rate Q through the secondary detection coil 12. be.

In this embodiment, the movable body 7 is the secondary detection coil 13
Since the sensor is only integrally connected to the sensor, the inertia is significantly reduced compared to the conventional example using a detection coil having a magnet. In particular, if the secondary detection coil 13 is made of aluminum wire, the inertia can be further reduced. Moreover, if the movable body 7 is made of light alloy, it is possible to significantly reduce the weight.

〔Effect of the invention〕

As explained above, according to the present invention, by significantly reducing the weight of the movable body from the collar portion and the cylindrical portion having the guide, the inertia can be lowered, and the response of the hydraulic servo system can be made even faster. Performance can be improved.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the flow rate and flow rate change rate detection device of the present invention. 1...Non-magnetic material pipe, 2...Fixed body, 3a, 3
b... End plate, 4a, 4b... Hole, 5... Rod, 6, 12... Annular projection, 7... Movable body, 8
a, 8b...Guide part, 9a, 9b...Opening hole, 1
0a, 10b...Brim part, 11...Cylindrical part, 13
...Secondary detection coil, 14a, 14b...Spring,
15...Permanent magnet, 16...Primary excitation coil.

Claims (1)

[Claims] 1. Flow rate and flow rate change rate for detecting the flow rate and flow rate change rate of the fluid flowing inside the pipe by detecting the displacement and speed of a movable body slidably provided in the pipe made of a non-magnetic material. The detection device includes: a permanent magnet and a primary excitation coil provided on the outer peripheral surface of the tube, a pair of end plates attached to the inner wall of the tube and having an opening, a rod integrally coupled with the end plate, and the rod. a fixed body having a first annular protrusion provided in the middle of the movable body; a second annular protrusion, a guide part that loosely fits into the rod, a pair of brim parts having an opening, and a cylindrical part that is integrally connected to the brim part and houses the second annular protrusion; A flow rate and flow rate change rate detection device, characterized in that the position is set at . 2. The flow rate and flow rate change rate detection device according to claim 1, wherein the first annular protrusion and the second annular protrusion have a rhombic cross-sectional shape.