KR102323804B1 - mass flow controller - Google Patents

Abstract

The present invention relates to a mass flow controller using magnetic levitation. The mass flow controller using magnetic levitation in accordance with the present invention comprises: a body having a flow path formed therein; a stem having a plug formed at an end thereof to open and close the flow path, and installed inside the body to be vertically movable; an armature protruding radially from the stem; a yoke forming an accommodation space for limiting movement of the armature in a vertical direction; a spring installed at a lower portion of the yoke to provide a vertical elastic force to the stem; a permanent magnet coupled to an upper portion of the yoke to provide a unidirectional magnetic force to the armature; a coil installed on the permanent magnet to provide a magnetic force in one direction and a reverse direction to the armature; and a guide unit in which an upper portion of the stem is accommodated and which guides vertical movement of the stem.

Description

Mass flow controller using magnetic levitation

The present invention relates to a mass flow controller, and to a mass flow controller using magnetic levitation capable of measuring and controlling the flow rate by adjusting the magnetic force of a coil and a permanent magnet.

A mass flow controller (MFC) is a device that sets, measures, and controls the flow rate and amount of fluid passing through the device.

Fluids include, by way of example, but not limited to, any kind of gas, vapor or liquid.

Mass flow controllers are typically designed and calibrated to very precisely control the flow of a fluid within a predefined flow range.

Some manufacturing processes, such as semiconductor manufacturing, require precise control over the fluid flow rate and quantity (mass) of gas or vapor being delivered to the process chamber or tool.

In the prior art related to such a mass flow controller, there are application number 10-2015-0063610 (application date: May 7, 2015), application number 10-2020-7012422 (application date: October 1, 2018), and the like.

Such a conventional mass flow controller has a problem in that it is difficult to quickly and precisely control the flow rate.

In addition, the solenoid valve, which controls the opening and closing of the valve through electromagnetic force using a coil, is suitable for opening and closing the valve, but is not suitable for linear control of a fluid, and has a disadvantage in that the opening and closing operation is noisy.

An object of the mass flow controller using magnetic levitation according to the present invention is to provide a mass flow controller using magnetic levitation capable of linear control of flow and precise flow control.

The mass flow controller using magnetic levitation according to the present invention includes a main body having a flow path, a stem having a plug for opening and closing the flow path formed at an end, installed inside the body to be vertically movable, and radially protruding from the stem Through the armature being formed, the yoke forming an accommodation space for limiting the movement of the armature in the vertical direction, the spring guide installed on the stem from the lower part of the yoke, and the upper and lower springs respectively installed on the upper and lower parts of the spring guide A spring providing an elastic force in the vertical direction to the stem, a permanent magnet coupled to the upper portion of the yoke to provide a one-way magnetic force to the armature, and magnetic force in one direction and a reverse direction to the polarizer, installed on the permanent magnet a coil providing a The plug seat is bolted to the nut portion formed in the flow path, and the plug seat can be operated from the outside by removing the sealing cap.

Here, it characterized in that it comprises a differential pressure sensor installed to sense the pressure on the output side of the flow path, and a control unit for adjusting the magnetic force of the coil through the differential pressure sensor.

The mass flow controller using magnetic levitation according to the present invention has the advantage of enabling linear control and precise control of the flow rate by regulating the movement of the poles installed on the stem through the magnetic force of the permanent magnet and the electromagnetic force of the coil.

1 is a cross-sectional view showing a mass flow controller using magnetic levitation according to a preferred embodiment of the present invention.
Figure 2 is an operational view of the mass flow controller using magnetic levitation according to a preferred embodiment of the present invention.
Fig. 3 is a change diagram of Fig. 2;
Fig. 4 is a change diagram of Fig. 2;
5 is a cross-sectional view showing a mass flow controller using magnetic levitation according to another preferred embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view illustrating a mass flow controller using magnetic levitation according to a preferred embodiment of the present invention.

As shown in FIG. 1 , the mass flow controller using magnetic levitation according to the present invention has a main body 130 , a stem 55 , a pole 40 , a yoke 80 , a spring 30 , and a permanent magnet 20 . , including a coil 10 and a guide unit 60 .

First, the main body 130 has a flow path connecting the inlet side (P1) and the outlet side (P2) is formed, and the differential pressure sensor 120 installed to sense the pressure is installed in the outlet side flow path, and the differential pressure sensor 120 ) through the control unit 110 for controlling the magnetic force of the coil.

That is, the control unit 110 adjusts the electromagnetic force of the coil through the pressure information of the flow path through the differential pressure sensor 120 to control the opening and closing amount of the flow path.

Next, as for the stem 55 , a plug 50 for opening and closing the flow path is formed at an end thereof, and is installed inside the body 130 to be vertically movable.

That is, opening and closing of the flow path is determined through vertical movement of the stem 55 .

The stem 55 has a radially protruding pole 40, and a yoke 70 for forming an accommodation space S for limiting movement of the pole 40 in the vertical direction is attached to the pole 40 ) of the upper and lower strokes are determined.

Next, the spring 30 is installed under the yoke 70 to provide an elastic force in the vertical direction to the stem 55, and the permanent magnet 20 is coupled to the yoke 70 and the armature ( 40) is provided with a unidirectional magnetic force, and the coil 10 is electromagnetized through an external power source and installed on the permanent magnet 20 to provide unidirectional and reverse magnetic force to the polarizer 40. .

Finally, the guide part 60 accommodates the upper portion of the stem 55 , guides the vertical movement of the stem, and prevents eccentricity in an arbitrary radial direction.

An operational aspect of the mass flow controller according to the present invention having such a configuration will be described.

2 is an operational view of a mass flow controller using magnetic levitation according to a preferred embodiment of the present invention, and FIGS. 3 to 4 are changes of FIG. 2 .

2 to 4 , white arrows indicate magnetic flux generated by the permanent magnet, and black arrows indicate magnetic flux generated by the electromagnetized coil.

First, as shown in FIG. 2 , the permanent magnet puts the armature 40 in an upward position. A spring guide 80 is installed on the stem 55 , and an upper spring 32 and a lower spring 34 are respectively installed on the upper and lower portions of the spring guide 80 .

The upper spring 32 and the lower spring 34 use a disc spring to provide a significant elastic force in a small area.

Here, in the upper position, since the magnetic force is greater than the elastic force of the spring, the stem moves upward and the flow path is opened. In this state, in order to close the flow path, current must be supplied to the coil 10 .

As shown in FIG. 3 , when current is supplied to the coil 10 , when the magnetic flux of the permanent magnet is temporarily canceled by the magnetic flux by the coil, the elastic force of the spring becomes greater than the magnetic force, and the pole 40 is located at the upper position and is accelerated in the downward direction by the elastic force of the spring.

In this case, as the plug installed at the end of the stem is moved to the lower portion, the open area of the flow path is gradually reduced.

When the polarizer 40 passes the neutral position of the upward movement stroke, current is applied to the electromagnetic coil in the reverse direction.

At this time, as shown in FIG. 4 , the permanent magnet and the electromagnetized coil contact the polarizer 40 to the lower position.

In the case of moving from this lower position to the upper position, it operates in the reverse order.

Next, another embodiment of the mass flow controller using magnetic levitation according to the present invention will be described.

It is necessary to easily adjust the tolerance value that affects the amount of opening and closing that occurs depending on the workpiece and the amount of opening and closing of the flow path that varies depending on the moving distance of the stem.

That is, it is necessary to control the flow amount of the fluid and to disassemble and maintain and repair when an abnormal phenomenon occurs in the flow of the fluid.

5 is a cross-sectional view illustrating a mass flow controller using magnetic levitation according to another preferred embodiment of the present invention.

As shown in FIG. 5 , a fastening part 131 communicating with the flow path is formed in the main body 100 , and the sealing cap 52 is maintained in a coupled state through the O-ring 133 in the fastening part 131 . do.

That is, the fluid flows in a state in which the sealing cap is normally coupled.

As described above, in order to adjust the movement distance deviation of the stem by adjusting the height of the plug seat 100 or to repair the abnormal flow inside, the sealing cap 52 is removed, and the plug seat 100 is used using an external tool. ) must be operated.

Accordingly, the plug sheet 100 is bolted to the flow path in which the plug 50 is in contact with the nut portion 51 , and the plug sheet 100 is sealed coupled to the fastening portion 131 formed in the body 100 . By removing the cap 52, the height can be easily manipulated through the driver (D) from the outside.

As described above, the present invention has a main technical idea to provide a mass flow controller using magnetic levitation, and since the embodiment described above with reference to the drawings is only one embodiment, the true scope of the present invention is defined in the claims. should be determined by

10: coil
20: permanent magnet
30: spring
32: upper spring
34: lower spring
40: armature
50: plug
51: nut part
52: sealing cap
55: stem
60: guide unit
70: York
80: spring guide
100: plug seat
110: control unit
120: differential pressure sensor
130: body
131: fastening part
133: O-ring
D: driver
S: accommodating space
P1: Inlet flow path
P2: Outflow Euro

Claims (3)

a body having a flow path formed therein;
a stem having a plug for opening and closing the flow path formed at an end thereof and installed inside the body to be vertically movable;
a contact pole radially protruding from the stem;
a yoke forming an accommodating space for restricting movement of the polarizer in the vertical direction;
a spring guide installed on the stem under the yoke;
a spring providing an elastic force in the vertical direction to the stem through an upper spring and a lower spring respectively installed in the upper and lower portions of the spring guide;
a permanent magnet coupled to an upper portion of the yoke to provide a unidirectional magnetic force to the polarizer;
a coil installed on the permanent magnet to provide magnetic force in one direction and a reverse direction to the polarizer;
A guide part for accommodating the upper part of the stem and guiding the vertical movement of the stem;
A sealing cap is coupled to a fastening portion formed in the body to communicate with the flow path, and a plug sheet is bolted to a nut portion formed in the flow path to the flow path in contact with the plug,
The mass flow controller using magnetic levitation, characterized in that the plug seat can be operated from the outside by removing the sealing cap.
The method of claim 1,
a differential pressure sensor installed to sense the pressure on the output side of the flow path;
Mass flow controller using magnetic levitation, characterized in that it comprises a control unit for adjusting the magnetic force of the coil through the differential pressure sensor.
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