JP4443156B2 - Gas inflow measurement sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas inflow state measuring sensor for detecting a state of gas flowing out from an outlet of an apparatus and grasping an operation state of the apparatus and a state of performance deterioration of the apparatus.
[0002]
[Prior art]
As well known, there are a pressure gauge for detecting the pressure of gas, a flowmeter for detecting the flow velocity of gas, and the like as a device for detecting the outflow state of gas.
[0003]
Pressure gauges include bourdon tubes, bellows, and diffused semiconductors. Generally, pressure gauges are used to measure gas pressure in a stationary state. The gas outflow is closed, and gas is released from the pressure gauge body. I can't let you.
[0004]
Further, Patent Document 1 discloses a spool that slides in a sleeve by receiving air pressure on an end surface thereof, a sensor rod that is coupled to a spool that transmits a movement amount of the spool, and a sensor rod that is externally fitted to the sensor rod. A pneumatic pressure sensor is disclosed which includes a sensor head that detects the amount of movement of the spool and sends a pressure signal, and a spring that urges the spool in a direction that prevents movement of the spool that receives pneumatic pressure. This pressure sensor also has a structure in which the air pressure to be measured is closed.
[0005]
On the other hand, the anemometer detects the gas flow velocity by applying an ultrasonic propagation velocity change method, an ultrasonic Doppler method, an ultrasonic beam deflection method, or the like.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-125572
[Problems to be solved by the invention]
By the way, when detecting the outflow state of the gas flowing out from the outflow port of the device, a method of detecting a pressure change state and a method of detecting a flow rate change are conceivable.
[0008]
It is also conceivable to apply a high-accuracy flowmeter, detect the gas flow velocity from the device, and detect the gas outflow state based on the flow velocity change. However, high-precision anemometers are large and expensive.
[0009]
Therefore, the present invention has been made in view of the above-described conventional problems, and can achieve downsizing and cost reduction, and accurately detect the inflow state of gas flowing out from the outlet of the device. It is an object of the present invention to provide a gas inflow state measuring sensor capable of performing the above-mentioned.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, a gas inflow state measurement sensor according to the present invention includes a cylinder having a gas discharge port formed in an inner peripheral wall, a piston inserted movably in the cylinder, and a piston sandwiched from both sides. , A gas that is provided with two springs that elastically support the piston at a position that closes the discharge port of the inner peripheral wall of the cylinder, and a moving position detecting means that detects the moving position of the piston, and is a gas partitioned by the inner peripheral wall of the cylinder and the piston A chamber is provided, an inflow hole is provided on the front side of the piston via the gas chamber, and gas is allowed to flow into the gas chamber from the inflow hole on the front side of the piston.
[0011]
According to the gas inflow state measuring sensor of the present invention having such a configuration, each spring sandwiches the piston from both sides and elastically supports the piston at a position where the discharge port of the cylinder inner peripheral wall is closed. The two springs that sandwich the piston from both sides are integrated into the two springs and the piston as a configuration in which the piston is inserted into the inner peripheral wall of the piston cut in a step shape so that it does not fall off the piston. In this state, the gas outlet is closed by the piston. When the gas flows from the inlet into the gas chamber partitioned by the piston, the pressure of the gas in the gas chamber rises, the piston is pushed by the gas pressure and moves, and the gas outlet gradually Open and gas begins to flow out of the outlet. Further, in a state where the gas flows along the path of the inlet → the gas chamber → the outlet, the outlet becomes an open state, and the inflowing gas is discharged from the outlet. Thereafter, when the gas flow stops, the pressure of the gas in the gas chamber decreases, the piston is pushed back to the position where it closes the discharge port of the cylinder inner peripheral wall by the elastic force of the spring, and the gas discharge port is closed.
[0012]
Thus, according to the start of gas flow, flow rate, and end of gas flow, the piston moves with high sensitivity and changes in the flow of gas per hour, and the discharge port on the inner wall of the cylinder opens and closes appropriately. Is done. Therefore, the change in the movement position of the piston corresponds to the gas inflow state into the gas chamber of the gas inflow state measurement sensor . For this reason, if the change of the moving position of the piston is detected by the moving position detecting means, the inflow state of the gas can be detected based on the change amount of the moving position of the piston. For example, if the gas flowing out from the EUT is caused to flow from the inlet to the gas chamber of the gas inflow state measurement sensor into the gas chamber, the outflow state of the gas from the EUT can be detected. The device has a gas outflow state during normal operation. By knowing the change in the outflow state, it is possible to know the deterioration state of the device and the occurrence of an abnormality.
[0013]
Moreover, since the structure of the gas inflow state measuring sensor of the present invention is simple, it is possible to reduce the size and the cost.
[0014]
In the present invention, the piston outer periphery and the cylinder inner periphery have a metal seal structure.
[0015]
In this way, the outer periphery of the piston and the inner periphery of the cylinder have a metal seal structure, so that the airtightness between the piston and the cylinder can be maintained, and the frictional resistance accompanying the movement of the piston in the cylinder can be suppressed. . Thereby, the detection accuracy per time of the inflow state of gas becomes high.
[0016]
Further, in the present invention, the two springs that sandwich the piston from both sides are engaged with both sides of the piston.
[0017]
Thereby, even if the piston moves at a high speed, the spring quickly follows the piston, and the spring does not move.
[0018]
In the present invention, the diameter of one end of the piston in contact with the gas chamber is gradually reduced.
[0019]
If the diameter of one end of the piston is gradually reduced in this way, the gas flow in the vicinity of one end of the piston is adjusted, and the gas smoothly flows from the gas chamber to the vicinity of the one end of the piston to the discharge port.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0021]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a gas inflow state measuring sensor of the present invention. In the gas inflow state measuring sensor of this embodiment, a cylinder 1a is formed in the housing 1, a hole 1b is formed on the right side of the cylinder 1a in the housing 1, and the cylindrical stator 2 is inserted into the hole 1b. The left end surface of the cylindrical stator 2 is brought into contact with the right end of the cylinder 1a. Then, the spring 3a is inserted into the cylinder 1a, the mover 5 connected to the right end surface of the piston 4 is inserted through the cylinder 1a into the central hole 2a of the cylindrical stator 2, the piston 4 is inserted into the cylinder 1a, After the spring 3b is inserted, the cap 6 is screwed into the left end of the housing 1.
[0022]
The piston 4 has a central portion 4a having a maximum diameter at the approximate center thereof. The outer diameter of the central portion 4a is slightly smaller than the inner diameter of the cylinder 1a, and the outer peripheral surface of the central portion 4a and the inner peripheral surface of the cylinder 1a form a metal seal structure. This metal seal structure keeps the airtightness between the piston 4 and the cylinder 1a and reduces the frictional resistance of the piston 4 accompanying the movement in the cylinder 1a, thereby enabling the piston 4 to move quickly.
[0023]
The metal seal structure means that a gas molecule layer is formed between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder, and the friction resistance between the piston and the cylinder is reduced while maintaining airtightness between the piston and the cylinder. All known structures that are possible.
[0024]
The spring 3a is compressed between the right side surface of the piston 4 and the left end surface of the cylindrical stator 2. Further, the spring 3 b is compressed between the left side surface of the piston 4 and the surface 6 a of the cap 6. And each spring 3a, 3b pinches the piston 4 from the both sides, and supports it elastically. In a state where no external force is applied to the piston 4, the springs 3 a and 3 b support the piston 4 at the positions of the discharge ports 1 c of the housing 1, and the central portion 4 a of the piston 4 closes the discharge ports 1 c of the housing 1.
[0025]
As each of the springs 3a and 3b, one having a small elastic coefficient is applied. Further, as described above, the central portion 4a of the piston 4 reduces the frictional resistance of the piston 4 and enables the piston 4 to move quickly. For this reason, even if a slight external force is applied, the piston 4 moves left and right within the cylinder 1a.
[0026]
The springs 3a and 3b are inserted into and engaged with the step portions at both ends of the piston 4. Thereby, even if the piston 4 moves at a high speed, the springs 3a and 3b quickly follow the piston 4, and the springs 3a and 3b do not rush.
[0027]
Since the mover 5 is connected to the right end surface of the piston 4, the mover 5 moves together with the piston 4. The cylindrical stator 2 detects the position of the mover 5 as the position of the piston 4.
[0028]
FIG. 2 illustrates the configuration of the cylindrical stator 2 and the mover 5. FIG. 3 is a circuit diagram showing the cylindrical stator 2 and the mover 5. The cylindrical stator 2 and the movable element 5 are so-called differential transformers. The mover 5 is a rod-shaped magnetic core. The cylindrical stator 2 includes a primary coil 2a and two secondary coils 2b and 2c.
[0029]
In this differential transformer, a constant AC voltage Ep is applied to the primary coil 2a to generate the induced voltages Es1 and Es2 in the secondary coils 2b and 2c, respectively, and the voltage Es that is the difference between the induced voltages Es1 and Es2 is generated. Extracted as detection output. When the mover 5 moves, the coupling coefficient between the primary coil 2a and each of the secondary coils 2b and 2c changes, and the voltage Es changes. Therefore, based on the voltage Es, the position of the mover 5 (the piston 4 Position) can be detected.
[0030]
The differential transformer includes not only those shown in FIGS. 2 and 3 but also various known configurations and circuits.
[0031]
Now, the gas inlet state sensor for measuring such a configuration, for example, in terms of connecting the inlet 6b of the cap 6 to the exhaust orifice of the device (not shown), the gas the gas flows from the exhaust orifice of the device It passes through the state measurement sensor and detects the inflow state of the gas .
[0032]
Here, since the external force is not applied to the piston 4 until immediately before the gas flows out from the exhaust orifice of the device, the two springs 3a and 3b sandwiched from both sides of the piston 4 are elastically supported. Thus, the central portion 4 a of the piston 4 closes each discharge port 1 c of the housing 1.
[0033]
Next, when the outflow of gas is started from the exhaust orifice of the device, the gas flows into the gas chamber 7 on the left side of the piston 4 from the inflow hole 6b of the cap 6, and the pressure of the gas chamber 7 rises, and the piston 4 is pushed and moved to the right by the pressure of the gas chamber 7, each discharge port 1 c of the housing 1 is gradually opened, and gas begins to be discharged from the gas chamber 7 to the outside through each discharge port 1 c.
[0034]
Next, in a state where the gas flows through the path of the inflow hole 6b → the gas chamber 7 → the discharge ports 1c, the springs 3a and 3b supporting the piston 4 expand and contract, and the pressure in the gas chamber 7 The piston 4 moves to a position where the elastic forces of the springs 3a and 3b are balanced. At this time, each discharge port 1c is opened widely and gas is discharged. Further, since the step portion is formed at the end of the piston 4 in contact with the gas chamber 7, the flow of gas in the vicinity of the end of the piston 4 is adjusted, and the gas passes from the gas chamber 7 to the vicinity of the end of the piston 4. And smoothly flows to the discharge port 1c.
[0035]
Next, when the outflow of the gas from the exhaust orifice of the device is completed and the inflow of the gas into the gas chamber 7 is stopped, the pressure in the gas chamber 7 is reduced, and the piston 4 is caused by the elastic force of each spring 3a, 3b. Is pushed back to the position of each discharge port 1 c, and the central portion 4 a of the piston 4 closes each discharge port 1 c of the housing 1.
[0036]
In this way, the piston 4 moves according to the start of gas inflow, the flow rate, and the end of inflow in the gas chamber 7, and the respective outlets 1c are appropriately opened and closed. Therefore, the change amount of the movement position of the piston 4 corresponds to the gas inflow state. For this reason, if the change amount of the movement position of the piston 4 is detected based on the detection output of the cylindrical stator 2, the gas inflow state can be detected based on the change amount of the movement position of the piston 4. The inflow state of gas from the device can be detected.
[0037]
Further, since the springs 3a and 3b having a small elastic coefficient are applied and the frictional resistance of the piston 4 is reduced by the central portion 4a, the piston 4 moves quickly and easily according to the pressure fluctuation in the gas chamber 7. To do. For this reason, the movement of the piston 4 hardly affects the outflow state of the gas from the device, and the detection error of the inflow state of the gas can be suppressed.
[0038]
Further, if the cap 6 is removed, the springs 3a and 3b, the piston 4 and the mover 5 are once taken out and the springs 3a and 3b are replaced with springs having other elastic coefficients, the detection characteristics of the gas inflow state measuring sensor . Can be changed.
[0039]
Further, the gas inflow state measuring sensor has a simple configuration including the housing 1, the piston 4, the springs 3a and 3b, the movable element 5, the cylindrical stator 2, and the cap 6, so that the size and cost can be reduced. Can be achieved.
[0040]
In addition, this invention is not limited to the said embodiment, It can deform | transform variously. For example, a differential transformer is used to detect the position of the piston. Instead, various contact sensors such as a potentiometer and various non-contact sensors can be applied.
[0041]
In addition, when the flow rate of gas flowing out from the outlet of the device to be measured is high, increase the diameter of the inlet of the gas inflow state measurement sensor and increase the flow area of the outlet of the inner wall of the cylinder. Thus, the release of gas flow rate that does not affect the performance of the EUT can be determined. Further, with respect to the gas pressure, at 1 MPa or less, the piston can be sandwiched from both sides without changing the two springs that elastically support the piston. If the pressure is higher than that, the sensor performance can be ensured by changing the spring characteristics.
[0042]
【The invention's effect】
As described above, according to the present invention, the piston moves according to the start of gas inflow, the flow rate, and the end of inflow, and the discharge port of the inner wall of the cylinder is appropriately opened and closed. Corresponds to the inflow state of gas. For this reason, if the variation | change_quantity of the movement position of a piston is detected by a movement position detection means, the inflow state of gas can be detected based on the movement position of a piston.
[0043]
In addition, since the gas inflow state measuring sensor of the present invention has a simple structure, the gas inflow state measuring sensor can be downsized and reduced in cost with respect to the gas flow rate and the gas pressure level. it can.
[0044]
Furthermore, since it has a metal seal structure between the outer periphery of the piston and the inner periphery of the cylinder, the airtightness between the piston and the cylinder can be maintained, and the frictional resistance accompanying the movement of the piston in the cylinder can be suppressed. Thus, the detection accuracy per hour of the gas inflow state is increased.
[0045]
Further, since the two springs sandwiching the piston from both sides are engaged with both sides of the piston, even if the piston moves at a high speed, the spring quickly follows the piston, and the spring does not move.
[0046]
Furthermore, since the diameter of one end of the piston in contact with the gas chamber is gradually reduced, the flow of gas in the vicinity of one end of the piston is adjusted, and the gas smoothly flows from the gas chamber to the vicinity of one end of the piston to the discharge port. .
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a gas inflow state measuring sensor according to the present invention.
2 is a longitudinal sectional view illustrating an example of the configuration of a cylindrical stator and a mover in the sensor of FIG. 1;
3 is a circuit diagram showing a cylindrical stator and a mover in the sensor of FIG. 1. FIG.

Claims (4)

A cylinder having a gas outlet formed in the inner peripheral wall;
A piston movably inserted into the cylinder;
Two springs that sandwich the piston from both sides and elastically support the piston at a position that closes the discharge port of the inner peripheral wall of the cylinder;
A moving position detecting means for detecting the moving position of the piston,
A gas chamber defined by the inner peripheral wall of the cylinder and the piston is provided, an inflow hole is provided on the front side of the piston via the gas chamber, and gas is allowed to flow from the inflow hole on the front side of the piston into the gas chamber. A gas inflow state measuring sensor characterized by. 2. The gas inflow state measuring sensor according to claim 1, wherein the piston outer periphery and the cylinder inner periphery have a metal seal structure. 2. The gas inflow state measuring sensor according to claim 1, wherein two springs sandwiching the piston from both sides are engaged with both sides of the piston. The gas inflow state measuring sensor according to claim 1, wherein the diameter of one end of the piston in contact with the gas chamber is gradually reduced.

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