JP2001141592A - Diaphragm pressure gage and its error measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm pressure gage capable of detecting deviation of a measured value caused by a secular change. SOLUTION: This pressure gage is equipped with a pressure measuring chamber communicated with a pressure measuring part, a hermetic high vacuum standard chamber, a diaphragm dividing the pressure measuring chamber and the high vacuum standard chamber and deformed by the pressure difference between both chambers, a detecting means for detecting a deformation quantity of the diaphragm, and a deforming means for giving deformation to the diaphragm, the error of a measured value caused by a secular change can thus be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm type pressure gauge, and more particularly to a diaphragm type pressure gauge having a function of self-diagnosing a change amount of a diaphragm due to aging.

[0002]

2. Description of the Related Art Generally, a conventional diaphragm type pressure gauge has a diaphragm 3 which is deformed by a pressure difference between a pressure measuring chamber 1 and a high vacuum reference chamber 2 as shown in FIG. The amount of deformation of the diaphragm 3 is set to the high vacuum reference chamber 2
Detected by an electrode 4 provided therein, converted into a pressure by an arithmetic circuit 5, and then output to the vacuum device main body 6.

In Japanese Utility Model Application Laid-Open No. 58-165640,
An electric capacitance detection type pressure gauge that detects displacement of a diaphragm as a change in electric capacitance is described. However, the technology disclosed herein is a pressure gauge that has good accuracy, reduces output pressure fluctuation due to atmospheric pressure fluctuation, and can be used as a gauge pressure gauge. Therefore, the present invention is different from the one provided with a means for detecting a measurement error due to aging according to the present invention.

Japanese Utility Model Application Laid-Open No. 3-16039 discloses a technique in which the distance between an electrode at the center and a diaphragm is made variable to correct errors due to manufacturing variations. However, in the technology disclosed herein, the first electrode 5
And the capacitance between the second electrode 6 and the diaphragm are adjusted so that the capacitance between the second electrode 6 and the second electrode 6 becomes equal at the zero point, thereby preventing the capacitance from crossing within the measurement range. Therefore, it is different from the one provided with a means for detecting a measurement error due to aging as in the present invention.

[0005]

On the other hand, the above-mentioned diaphragm type pressure gauge has the following problems.
The first problem is that when the deformation is changed due to the deterioration of the diaphragm or the attachment of foreign matter or the like, the pressure gauge itself has no means for detecting the change in the deformation. Therefore, it was necessary to separately attach and confirm another pressure gauge, but the work for that was complicated, and when an error of the pressure gauge was found, many product abnormalities occurred in many cases.

Further, in recent vacuum process technology, a product difference often occurs due to a slight difference in pressure, and severe management of pressure is required.

An object of the present invention is to provide a diaphragm-type pressure gauge having an error detecting function in order to improve the above-mentioned conventional disadvantages.

[0008]

In order to solve the above-mentioned problems, the present invention basically employs the following configuration. That is, the diaphragm-type pressure gauge according to the present invention, the pressure measurement chamber communicating with the pressure measurement unit, a sealed high vacuum reference chamber, and the pressure measurement chamber and the high vacuum reference chamber is partitioned, the two chambers A diaphragm deformed by a pressure difference, detecting means for detecting a deformation amount of the diaphragm, and deforming means for deforming the diaphragm are provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A diaphragm pressure gauge and a diaphragm pressure gauge according to the present invention are provided with a pressure measuring chamber communicating with a pressure measuring section, in order to solve the above-mentioned problems in the prior art. A sealed high-vacuum reference chamber, a diaphragm that partitions the pressure measurement chamber and the high-vacuum reference chamber and deforms due to a pressure difference between the two chambers, a detecting unit that detects an amount of deformation of the diaphragm, and a deformable diaphragm. And a deformation means for adding the pressure, so that a measurement error can be detected without using another pressure gauge.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a diaphragm type pressure gauge and one example of a diaphragm type pressure gauge according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a first embodiment of a diaphragm type pressure gauge according to the present invention. Here, a pressure measurement chamber 11 communicating with the pressure measurement unit and the vacuum device main body 10, a sealed high vacuum reference chamber 12, and the pressure measurement chamber 11 and the high vacuum reference chamber 12 are partitioned. Diaphragm 1 deformed by pressure difference
3, an electrode 14 which is a detecting means for detecting the amount of deformation of the diaphragm, and a solenoid 15 and a magnetic body 16 which are deforming means for deforming the diaphragm 13.

The deformation of the diaphragm 13 is caused by the pressure measuring chamber 1
If the pressure in the pressure measurement chamber 11 is high vacuum, the diaphragm 13 does not deform much because the pressure difference is small, and if the pressure in the pressure measurement chamber 11 is low vacuum, the pressure difference becomes large and the diaphragm 13 becomes high vacuum reference chamber 12. It is pushed to the side and deforms.

An electrode 14 is provided in the high vacuum reference chamber 12 and is connected to an arithmetic circuit 17. The electrode 14 can detect the amount of deformation of the diaphragm 13 by measuring the capacitance. When the pressure in the pressure measurement chamber 11 changes, the diaphragm 13 deforms and the capacitance between the diaphragm 13 and the electrode 14 changes. This change in capacitance is measured by the electrode 14, converted by the arithmetic circuit 17, detected as a change in pressure, and output to the vacuum device main body 10.

In this embodiment, as shown in FIG. 1, a magnetic body 16 is disposed on a surface of the diaphragm 13 opposite to a pressure surface to be measured, and a solenoid 15 is provided at a position facing the magnetic body 16. The solenoid 15 is connected to a power supply circuit 18, and the magnetic substance 16
Has the function of distorting the diaphragm 13 to which the magnetic body 16 is attached. Also, the solenoid 15
When electricity is supplied to the diaphragm 13, the magnetic force generates a force to pull the magnetic body 16, so that the diaphragm 13 is pulled toward the high vacuum reference chamber 12 and deformed. The displacement amount due to the distortion of the diaphragm 13 is the same as in the pressure measurement,
The capacitance can be measured by the electrode 14.

Under the condition that the power supplied to the solenoid 15 is constant, the attraction to the magnetic body 16 is constant, and a reference can be set for the displacement of the diaphragm 13. The aging of the amount of distortion of the diaphragm 13 that occurs when the diaphragm type vacuum gauge is used over time is determined by the solenoid 15.
Appears in the change in the amount of displacement of the diaphragm 13 composed of the electric power supplied to the diaphragm 13. In the present invention, it is possible to detect an abnormality in the amount of change of the diaphragm 13 by comparing with a reference value.

Next, the actual operation of the diaphragm type pressure gauge according to the present invention will be described with reference to FIGS. First, in a normal pressure measurement state, the power supply output from the power supply circuit 18 to the solenoid 15 is in an OFF state. Therefore, no electricity is supplied to the solenoid 15 and no magnetic force is generated, so that the diaphragm 13 is not affected by the magnetic force by the solenoid 15.

The deformation of the diaphragm 13 is caused by the pressure measurement chamber 1
It occurs only due to the pressure difference between 1 and the high vacuum reference chamber 12,
This amount of deformation is measured as capacitance at the electrode 14. The pressure is converted into a pressure value by the arithmetic circuit 17 and output to the vacuum device main body 10 as a pressure value.

Next, the self-diagnosis function of the pressure error will be described. The vacuum apparatus main body 10 receives the signal of the pressure value from the arithmetic circuit 17 and confirms that the vacuum state is about 1/100 of the measurement range of the pressure gauge. In other words, the pressure measurement does not need to be performed (the pressure measurement chamber 11 and the high vacuum reference chamber 1).
When it is determined that the pressure difference is smaller than the pressure difference from the control signal No. 2, the arithmetic circuit 17 outputs a signal for operating the error self-diagnosis function.
The arithmetic circuit 17 stores the measured pressure value at that time, and issues a command to the power supply circuit 18 to supply power to the solenoid 15. The output of the power supply circuit 18 is turned on to supply power to the solenoid 15.

The solenoid 15 supplied with electricity pulls the diaphragm 13 toward the high vacuum reference chamber 12 by magnetic force. At this time, the displacement of the diaphragm 13 is
Is measured as an electrostatic capacitance, and sent to the arithmetic circuit 17 to be converted as a pressure value. The arithmetic circuit 17 calculates the pressure difference between the pressure value at this time and the pressure value stored at the start of the error self-diagnosis function operation. If the value is within the specified range, it is determined that there is no abnormality. And sends an alarm signal to the vacuum apparatus main body 10. After that, the arithmetic circuit 17
Sends an output power output OFF signal to the power supply circuit 18,
The pulling of the diaphragm 13 by the solenoid 15 is stopped, and the state returns to the normal pressure measurement state.

Next, the difference between the normal operation and the abnormal operation will be described with reference to FIGS. The figure shows an example of the operation when a pressure gauge having a full scale of 1330 Pa is used. First, during normal operation, when measuring pressure, as shown in FIG. 2, the measured pressure output sent from the arithmetic circuit 17 to the vacuum apparatus main body 10 shows the same value as the pressure in the pressure measurement chamber 11, and at point A, 931 Pa is shown. Point B is a point where the measured pressure output is 0 Pa. At this time, it is determined that the vacuum device main body 10 does not need to measure the pressure and is in a vacuum state of about 1/100 of the measurement range of the pressure gauge, and the pressure error self-diagnosis function is operated.

The output of the power supply circuit is turned on, and the diaphragm 13 is turned on.
Is pulled toward the high vacuum reference chamber 12 by the magnetic force, and the measured pressure output becomes 1064 Pa. The standard of the measured pressure output during the operation of the error self-diagnosis function provided in the arithmetic circuit 17 is 10
Assuming a range of 37.4 Pa to 1090.6 Pa, 1064 Pa is a normal value. Therefore, the arithmetic circuit 1
When the self-diagnosis is completed at the point C, the alarm is not output to the vacuum apparatus main body 10, but the power supply circuit output is turned off to return to the original pressure measurement state. As shown in FIG. 3, when an error occurs in which a span shift occurs, the vacuum device 1
The measured pressure output sent to 0 shows a different value from the actual pressure, and at point A, the pressure in the pressure measurement chamber is 85
1.2 Pa, whereas the measured pressure output is 931 Pa
It is.

From the point B, when the vacuum apparatus main body 10 operates the pressure error self-diagnosis function, the measured pressure output indicates 1163.8 Pa. In this case, the arithmetic circuit 17 determines that there is an abnormality, and outputs an alarm signal to the vacuum device main body 10 because the value is out of the above-mentioned standard range of 1037.4 Pa to 1090.6 Pa.

FIG. 4 is a schematic configuration diagram showing another embodiment of the diaphragm type pressure gauge of the present invention. In the present embodiment, a strain gauge 19 is provided on the high vacuum reference chamber 12 side of the diaphragm 13.
The signal is input to the arithmetic circuit 17. FIG. 4 is different from FIG. 1 in that a strain gauge 19 is added and the electrode 14 is omitted. This is because the amount of deformation of the diaphragm 13 is measured by the capacitance at the electrode 14 in FIG. 1, but is measured as electric resistance by the strain gauge 19 in FIG. As described above, in the vacuum gauge using the diaphragm 13, the technique of measuring the amount of deformation of the diaphragm 13 is not limited, but a span shift self-diagnosis function can be applied.

Next, the error measuring method of the present invention will be described. First, a pressure measurement chamber 11 communicating with the vacuum apparatus main body 10, a sealed high vacuum reference chamber 12, and the pressure measurement chamber 11 and the high vacuum reference chamber 12 are partitioned and deformed by a pressure difference between the two chambers. Diaphragm, comprising: a diaphragm 13 to be deformed; detecting means for detecting the amount of deformation of the diaphragm 13; deforming means for deforming the diaphragm; and an arithmetic circuit 17 for controlling the vacuum device main body, detecting means and deforming means. In the pressure gauge, in the pressure setting step, the arithmetic circuit 17 adjusts the degree of vacuum of the vacuum device body 10 to the high vacuum reference chamber 1.
Set to a pressure approximately equal to 2.

Next, in the deformation step, the deformation means gives the same deformation as when a predetermined pressure is applied to the diaphragm 13. The deforming means is, for example, a magnetic body 16 and a solenoid 15
It is. Next, in the detecting step, the amount of deformation when the same deformation as when a predetermined pressure is applied to the diaphragm 13 by the deforming means is detected by the detecting means. The detection means is, for example, the electrode 14 and measures the change as a change in capacitance.

In the comparing step, the detection result of the detecting means is compared with a predetermined pressure value applied to the diaphragm 13 by the deforming means by the arithmetic circuit 17. When the measured value exceeds a predetermined range as a result of the comparison in this comparison step, an alarm is output to the vacuum apparatus main body 10 in the alarm step. As described above, in the diaphragm pressure gauge and the error measurement method of the present invention, by applying a force different from the pressure to the diaphragm, the state of the diaphragm can be confirmed, and the span shift can be confirmed. Self-diagnosis becomes possible.

The present invention is not limited to the above-described embodiments, and various design changes can be made based on the technical concept of the present invention.

[0027]

The first effect is that it is possible to prevent a large amount of abnormal product from flowing out due to a difference in pressure span. The reason is that by having the self-diagnosis function, the span deviation of the pressure can be easily checked, and an abnormality can be found at an early stage. By making it possible to apply a force different from the pressure to the diaphragm for measuring the pressure, the state of the diaphragm can be confirmed, so that self-diagnosis of span shift is possible and checking can be easily performed Because.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a first embodiment of a diaphragm type pressure gauge according to the present invention.

FIG. 2 is an operation explanatory diagram of the diaphragm type pressure gauge.

FIG. 3 is an explanatory diagram of an operation of a diaphragm type pressure gauge when a span shift occurs.

FIG. 4 is an explanatory view showing a schematic configuration of a diaphragm type pressure gauge according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a conventional diaphragm type pressure gauge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure measurement chamber 2 High vacuum reference chamber 3 Diaphragm 4 Electrode 5 Operation circuit 6 Vacuum apparatus main body 10 Vacuum apparatus main body 11 Pressure measurement chamber 12 High vacuum reference chamber 13 Diaphragm 14 Electrode 15 Solenoid 16 Magnetic body 17 Operation circuit 18 Power supply circuit 19 Distortion gauge

Claims (7)

[Claims] 1. A diaphragm which divides a pressure measurement chamber communicating with a pressure measurement section, a sealed high vacuum reference chamber, and the pressure measurement chamber and the high vacuum reference chamber, and is deformed by a pressure difference between the two chambers. And a detecting means for detecting the amount of deformation of the diaphragm, and a deforming means for deforming the diaphragm. 2. The diaphragm-type pressure gauge according to claim 1, wherein said detection means is an electrode disposed at a predetermined distance from the diaphragm. 3. The diaphragm-type pressure gauge according to claim 1, wherein said detection means is a strain gauge installed on a diaphragm. 4. The apparatus according to claim 1, wherein said deforming means comprises a magnetic member mounted on a diaphragm and a solenoid disposed in said high vacuum reference chamber so as to face said diaphragm. 4. The diaphragm type pressure gauge according to any one of items 1 to 3. 5. A comparison operation circuit compares a detection signal from a detection means for detecting a deformation amount of the diaphragm with a reference change amount by a deformation means for deforming the diaphragm, and outputs an alarm based on the comparison result. The diaphragm type pressure gauge according to any one of claims 1 to 4, wherein: 6. A comparison operation circuit compares a detection signal from a detecting means for detecting an amount of deformation of the diaphragm with a reference change amount by a deforming means for deforming the diaphragm, and a comparison result exceeds a standard range. The diaphragm type pressure gauge according to any one of claims 1 to 5, wherein an alarm is output in such a case. 7. A diaphragm which divides a pressure measurement chamber communicating with a vacuum device main body, a sealed high vacuum reference chamber, and the pressure measurement chamber and the high vacuum reference chamber, and is deformed by a pressure difference between the two chambers. Detection means for detecting the amount of deformation of the diaphragm, deformation means for applying a deformation to the diaphragm,
In a diaphragm type pressure gauge provided with an arithmetic circuit for controlling said vacuum device main body, a detecting means and a deformation means, a pressure setting step in which said arithmetic circuit sets the degree of vacuum of said vacuum device main body to a pressure substantially equal to a high vacuum reference chamber And a deformation step in which the deformation means applies a deformation equivalent to a case where a predetermined pressure is applied to the diaphragm, and a deformation amount when the deformation means applies a deformation equivalent to the case where a predetermined pressure is applied to the diaphragm. A comparing step of comparing the detection result of the detecting means with a predetermined pressure value given to the diaphragm by the deforming means by an arithmetic circuit, and a result of the comparison in the comparing step is a predetermined predetermined value. An error measuring method for a diaphragm-type pressure gauge, comprising an alarming step of generating an alarm when an allowable value is exceeded.