JPH0148969B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a casing in which an inner member having a single helical thread shape is fixed, and an outer member having a double helical thread bored therein is rotatably mounted. The present invention relates to a positive displacement flowmeter that is installed inside the interior of the vehicle and measures the passing flow rate from the eccentric rotation of an outer member caused by fluid.

(Prior art) Conventionally, so-called monoflow flowmeters used to measure the flow rate of high-viscosity fluids include, for example, the JP-A-57
−88323 is known.

This positive displacement flowmeter has a basic structure in which a rotor with a single thread is rotatably built into a stator with a double thread female thread, and between the stator and the rotor. By forcing pressurized fluid into the formed gap, the rotor is eccentrically rotated while being inscribed in the stator, and the passing flow rate is measured by detecting the eccentric rotation of the rotor.

(Problems to be Solved by the Invention) However, in such conventional positive displacement flowmeters, the rotor is rotated eccentrically within the stator (revolutionary motion accompanied by rotation) by fluid force, and the eccentricity of the rotor is Since the structure was designed to measure the flow rate through rotation, it was necessary to provide a bearing structure to support the rotor eccentrically in the fluid flow path, and since the bearing part is exposed to the fluid, The structure must take into account wear and tear caused by corrosion and dirt, and the bearings are complex and large because they use universal joints and planetary gears that convert eccentric rotation of the rotor into rotational motion around the stator axis. The problem was that the rotor's rotational resistance and noise increased.

(Means for Solving the Problems) The present invention has been made in view of the above-mentioned problems of the conventional art. The purpose of the present invention is to provide an excellent positive displacement flowmeter, which is constructed as follows.

That is, a cylindrical rotor chamber is formed in a casing through which a fluid passage is penetrated, and a rotor member having a cylindrical outer shape with a double-threaded helical screw bored inside is installed in the rotor chamber so as to be eccentrically rotatable. 2
A stator member having a single helical thread shape inscribed in the threaded helical thread is fixed and installed on the casing side,
Furthermore, the eccentric rotation of the stator member within the rotor chamber due to the fluid is detected by a detection means such as a magnetic pickup, and the passing flow rate is measured and displayed.

That is, in the present invention, the conventional rotor member is fixed,
The above object is achieved by having a reverse configuration in which the outer stator member is rotated.

(Embodiment) FIG. 1 is a sectional view showing an embodiment of the present invention.

First, the structure will be described. Reference numeral 1 is a casing having a two-part structure with a fluid passage formed therein, and flanges 2 for connecting to piping are integrally formed on both sides of the casing 1. A cylindrical rotor chamber 3 is formed inside the casing 1, and a rotor member 4 having a cylindrical outer shape with a double-thread female thread 8 bored inside the rotor chamber 3 is eccentrically rotated, that is, the rotor chamber 3 is rotated eccentrically. Rotor axis center line 5 due to sliding contact
It is incorporated so that it rotates around the casing axis and also rotates around the casing axis 6. The rotor member 4 has large-diameter rolling flanges 7 formed at both ends in order to reduce the contact area with the inner circumferential wall of the rotor chamber 3 and enable smooth eccentric rotation.

A stator member 1 having an external shape of a single helical thread is included in a double-thread female thread 8 bored inside the rotor member 4 which is eccentrically rotatably incorporated into the rotor chamber 3.
0 is inscribed in the stator member 10, and the stator member 10 is fixedly arranged by fitting fixed shafts 11 at both ends into shaft fixing portions 12 extending inside the casing 1.

A rotor member 4 having a double-thread internal thread 8 built into the rotor chamber 3 so as to be eccentrically rotatable, and a stator having an external shape of a single-thread helical thread inscribed and fixed in the rotor member 4. Part 1
0 realizes the basic structure of the flowmeter of the present invention. That is, there is a gap C1 between the eccentrically rotatable rotor member 4 and the fixed stator member 10.
If C2 and C3 are partitioned and pressurized fluid is supplied from the left side of the casing 1 as indicated by the arrow, for example, the outer rotor member 4 is connected to the rotor chamber 3 while the inner stator member 10 is fixedly arranged under fluid pressure. Eccentric rotation occurs within the air gap C1, C2, C
Since the volume of the rotor member 3 is predetermined, the rotor member 4 causes an eccentric circuit according to the passing flow rate, and therefore, the passing flow rate can be measured by detecting the eccentric rotation of the rotor member 4. can.

Next, we will explain the means for detecting eccentric rotation of the rotor member 4 and displaying the measured flow rate. First, the rotor member 4 and the casing 1 are made of a non-magnetic material such as aluminum, and a magnet is attached to the outer periphery of the rotor member 4. The ring 13 is fixed, and a pick-up coil 14 is provided in the upper part of the casing 1 facing the magnet 13, so that when the rotor member 4 rotates eccentrically upward as shown in the figure, the magnetic flux changes due to the proximity of the magnet ring 13. Pick up coil 14
It is designed to induce a pulse-like voltage.
The pulse voltage of the pickup coil 14 obtained by one eccentric rotation of the rotor member 4 is applied to a flow rate measuring circuit provided inside an indicator 15 installed in the upper part of the casing 1. Since there is a built-in counter that counts the voltage pulses from the rotor member 4, and since the passing flow rate per eccentric rotation of the rotor member 4 is determined, the number of pulses per unit time is counted and this is multiplied by the passing flow rate. This allows the flow rate display section 16 to numerically display the passing flow rate.

Next, the flow rate measurement operation according to the embodiment shown in FIG. 1 will be explained.

Now, if the pressurized fluid is supplied from the left side of the casing 1 as shown by the arrow, the pressurized fluid enters the gap C1 on the inlet side formed between the rotor member 4 and the stator member 10, and enters the inner side. Since the stator member 4 is fixed, a rotational force is applied to the outer rotor member 10, and as a result, the outer rotor member 4 rotates around the rotor axis 5 while being inscribed in the inner stator member 10. Eccentric rotation that causes rotation and revolution around the casing axis 6 begins.

Figures 2, 3 and 4 each show the fixedly installed inner stator member 1 when supplied with pressurized fluid.
The eccentric rotation of the outer rotor member 4 with respect to 0 is extracted and shown. FIG. 2 shows the initial state of FIG. It is located at an eccentric position. When pressurized fluid is supplied from the left side in the state shown in Fig. 2, the rotor member 4 causes eccentric rotation in a predetermined direction determined by the threading direction of the double helical screw, and rotates 90 degrees from the state shown in Fig. 2. Now, as shown in FIG. 3, the rotor member 4 and the stator member 1 are
The gaps C1, C2, and C3 between 0 and 0 move to the right, which is the exit side, and when the rotor member 4 rotates 180 degrees from the position shown in FIG. 2, the rotor member 4 shown in FIG. The state is eccentric to the side, and the gaps C1 and C between the rotor member 4 and the stator member 10 are
2, C3 further moves to the exit side. Due to the eccentric rotation caused by the fluid pressure of the outer rotor member 4 due to the internal contact with the stator member 10 fixed on the inner side, the fluid from the inlet side is transferred to the outlet side by the movement of the gap, and the volume of the gap is kept constant. Therefore, it is possible to obtain eccentric rotation of the rotor member in proportion to the passing flow rate.

A magnet ring 13 is provided on the outside of the rotor member 4.
is fixed, and when the rotor member 4 eccentrically rotates to the upper side of the casing axis 6 as shown in FIG. A pulse voltage is induced in the pick-up coil 14 due to a change in magnetic flux due to the proximity of the magnet ring 13, and the pick-up coil 14 generates one pulse voltage for each eccentric rotation of the rotor member 4, that is, for each revolution. The pulse voltage of the pickup coil 14 is counted by a counter of a measuring circuit built into the display 15, and the count value per unit time is calculated by the gaps C1 and C.
By multiplying the total volume (constant) of C.2 and C3, the flow rate passing per unit time is calculated, and this calculated flow rate is numerically displayed on the flow rate display section 18.

Next, the operation of the embodiment shown in FIG. 1 will be explained in comparison with a conventional case in which the inner stator 10 is eccentrically rotatable and the outer rotor member 4 is fixed. Since the stator member 4 having an external threaded shape is only fixedly arranged by the shaft fixing part 12, there is no need for a bearing structure for this stator member 10 at all.
Since no bearing structure is provided in the flow path, there is no need to consider corrosion or durability of the bearing structure. Further, the outer rotor member 4 is connected to the inner stator member 1.
By simply incorporating the bearing into the rotor chamber 3 of the casing 1 while inscribed in the rotor chamber 3, it can rotate eccentrically within the rotor chamber 3 without requiring a special bearing structure.
The structure is extremely simple.

In order to smooth the eccentric rotation of the rotor member 4 within the rotor chamber 3, it is desirable to select a material for the rotor member 4 to further reduce its weight.
Further, since the rotor member 4 is subjected to a force in the thrust direction due to fluid pressure, it is desirable to interpose a ball bearing or the like on the end face of the rotor member 4 so that the movement of the rotor member 4 is not hindered by the thrust force. .

Furthermore, in the embodiment shown in FIG. 1, the magnet ring 13 is directly fixed to the outside of the rotor member 4, and the rotation is detected by the pickup coil 14 according to the change in the eccentric position of the rotor member 4 with respect to the casing axis 6. However, in another embodiment, a plurality of magnetic bars are embedded radially in the end surface of the rotor member 4 at predetermined intervals, and a pick-up coil is provided opposite to the end surface where the magnetic bars are embedded. The passing flow rate may be measured from the number of rotations. Of course, it is also possible to extract only the orbital motion of the rotor member 4 during eccentric rotation, rotate the magnetic pole rotor, and measure the passing flow rate from the rotational speed of the magnetic pole rotor.

(Effects of the Invention) As described above, according to the present invention, a cylindrical rotor chamber is formed in a casing through which a fluid passage is penetrated, and the rotor chamber has a cylindrical outer shape with a double-threaded helical screw bored therein. A rotor member is installed eccentrically rotatably, a stator member having an external shape of a single helical thread is inscribed in a double helical thread of the rotor member, and is fixedly installed in the casing, and further, the rotor member is rotated by supplying pressurized fluid. Since a means is provided to detect eccentric rotation indoors and measure and display the passing flow rate, there is no need to provide a bearing structure inside the fluid passage since the rotation is a helical rotor with a fluid passage inside. In addition, the outer rotor member does not require any special support structure in the rotor chamber of the casing, and can simply be incorporated into the rotor chamber of the casing to receive pressurized fluid and rotate eccentrically through internal contact with the stator member fixedly installed inside. The structure for obtaining eccentric rotation according to the passing flow rate is extremely simple, and the rotor rotation can be detected separately from the fluid passage passing through the interior, so it is possible to detect fluid mixed with sand or dirt. Even when measuring , it is not affected by the measuring fluid.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIGS. 2, 3, and 4 are explanatory views showing eccentric rotation of a rotor member due to fluid. 1: Casing, 2: Flange, 3: Rotor chamber, 4: Rotor member, 5: Rotor axis, 6: Casing axis, 7: Rolling flange, 8: Female thread, 10: Stator member, 11 : Fixed axis, 12:
Shaft fixing part, 13: Magnet ring, 14: Pick-up coil, 15: Display, 18: Flow rate display part.

Claims (1)

[Claims] 1. A cylindrical rotor chamber is formed in a casing through which a fluid passage is penetrated, and a rotor member having a cylindrical outer shape with a double spiral internal thread is installed in the rotor chamber so as to be eccentrically rotatable. A stator member inscribed in the screw and having the external shape of a single helical screw is fixedly installed on the casing side, and furthermore, eccentric rotation of the rotor member in the rotor chamber due to supply of pressurized fluid is detected to measure the passing flow rate. A positive displacement flowmeter characterized by being provided with a means for measuring and displaying measurements.