JP2001099634A - Air micro-meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air micro-meter capable of accurately measuring. SOLUTION: For an air micro-meter 10 controlling compressed air supplied from an air source 28 at constant pressure with a regulator 14 and discharging through a throttle placed in an A/E converter 16 from the air nozzle 22 of a jet 12, the length of the air pipe 30C between the air source 28 and the regulator 14 is made sufficiently long. By this, the compressed air supplied from the air source 28 becomes the same temperature as the room temperature during introducing through the air pipe 30 into the regulator 14. As the result, thermal deformation of the A/E converter 14, the jet 12 and a work 24 due to the temperature change in compressed air can be prevented and accurate measurement is made always possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air micrometer, and more particularly, to a method for measuring an air micrometer having a variation width of 0.5.
The present invention relates to an air micrometer that performs highly accurate measurement of μm or less.

[0002]

2. Description of the Related Art A back pressure air micrometer adjusts compressed air supplied from an air source to a constant pressure by a regulator as a pressure adjusting means, and injects the air from a jet air nozzle through a throttle to make the air nozzle at that time. The size of the work is measured by detecting the change in back pressure.

[0003]

However, when the temperature of the compressed air jetted from the jet air nozzle changes, the dimensions of the jet and the object to be measured change, so that high-precision measurement cannot be performed. In particular, in an air micrometer that detects a change in back pressure of an air nozzle using an air / electric converter (hereinafter, referred to as an “A / E converter”), the temperature of compressed air passing through the A / E converter is low. If it changes, an error due to a temperature characteristic inherent in the built-in differential transformer (an error due to thermal deformation, an error due to a change in the electric resistance of the coil of the LVDT, etc.) occurs, and the accuracy deteriorates.

The present invention has been made in view of such circumstances, and has as its object to provide an air micrometer capable of performing highly accurate measurement.

[0005]

The invention according to claim 1 is
In order to achieve the above object, an air micrometer that adjusts air supplied from an air source to a constant pressure by a pressure adjusting unit, measures the size of a workpiece by jetting from a jet air nozzle through a throttle, and from the air source. The length of a pipe connecting the air source and the pressure adjusting means is set such that the supplied air has the same temperature as room temperature while being introduced into the pressure adjusting means, I do.

According to the present invention, the air supplied from the air source has the same temperature as the room temperature before being introduced into the pressure adjusting means. As a result, it is possible to prevent a temperature characteristic error of the air / electric converter and a thermal deformation of the jet and the work caused by a change in the temperature of the supply air, so that highly accurate measurement can always be performed.

According to a second aspect of the present invention, in order to achieve the above object, the air adjusted to a constant pressure by the pressure adjusting means is jetted from a jet air nozzle through a throttle,
A temperature at which the temperature of the air introduced into the air / electric converter is detected in an air micrometer which measures the size of the work by converting a change in the back pressure of the air nozzle into an electric signal with an air / electric converter at that time. Detecting means, a temperature adjusting means provided upstream of the temperature detecting means for adjusting the temperature of air introduced into the air / electric converter, and the air / electricity detecting means based on a detection result of the temperature detecting means. Control means for controlling the temperature control means so that the temperature of the air introduced into the converter becomes a predetermined temperature.

According to the present invention, the temperature of the air introduced into the air / electric converter is detected by the temperature detecting means, and the temperature is adjusted by the temperature adjusting means so that the temperature always becomes a predetermined temperature. Accordingly, it is possible to prevent a temperature characteristic error of the air / electric converter caused by a change in the temperature of the air introduced into the air / electric converter, and to always perform highly accurate measurement.

According to a fourth aspect of the invention, in order to achieve the above object, the air adjusted to a constant pressure by the pressure adjusting means is jetted from a jet air nozzle through a throttle,
Temperature detecting means for detecting a temperature of air jetted from the air nozzle, in an air micrometer for measuring a size of a work by converting a change in back pressure of the air nozzle into an electric signal by an air / electric converter at that time; Temperature control means provided upstream of the temperature detection means for adjusting the temperature of the air jetted from the air nozzle; and adjusting the temperature of the air jetted from the air nozzle to a predetermined temperature based on the detection result of the temperature detection means. And control means for controlling the temperature control means so that

According to the present invention, the temperature of the air jetted from the air nozzle is detected by the temperature detecting means, and the temperature is adjusted by the temperature adjusting means so that the temperature always becomes a predetermined temperature. Thereby, thermal deformation of the jet or the work based on the temperature change of the air injected from the air nozzle can be prevented, and highly accurate measurement can be always performed.

According to a sixth aspect of the present invention, in order to achieve the above object, air adjusted to a constant pressure by a pressure adjusting means is jetted from a jet air nozzle through a throttle installed in an air / electric converter. An air micrometer for measuring the size of the workpiece by means of a first temperature detecting means for detecting the temperature of the air injected from the air nozzle, and being provided between the air / electric converter and the air nozzle; First temperature control means provided on the upstream side of the temperature detection means for adjusting the temperature of air injected from the air nozzle, and second temperature detection means for detecting the temperature of air introduced into the air / electric converter , And installed between the pressure adjusting means and the air / electric converter, and provided upstream of the temperature detecting means and introduced into the air / electric converter. Second temperature control means for adjusting the temperature of the air, and controlling the first temperature control means based on the detection result of the first temperature detection means such that the temperature of the air injected from the air nozzle becomes a predetermined temperature. And control means for controlling the second temperature control means so that the temperature of the air introduced into the air / electric converter becomes a predetermined temperature based on the detection result of the second temperature detection means. It is characterized by the following.

According to the present invention, the temperature of the air injected from the air nozzle is detected by the first temperature detecting means, and the temperature is adjusted by the first temperature adjusting means so that the temperature always becomes a predetermined temperature. The temperature of the air introduced into the electric converter is detected by the second temperature detecting means, and the temperature is adjusted by the second temperature adjusting means so that the temperature always becomes a predetermined temperature. Thereby, it is possible to prevent a temperature characteristic error of the air / electric converter caused by a change in the temperature of the supply air, and to prevent thermal deformation of the jet and the work, and to always perform highly accurate measurement.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the air micrometer according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of a back-pressure air micrometer for measuring an inner diameter to which the present invention is applied. As shown in FIG. 1, the air micrometer 10 mainly includes a jet 12 (measuring unit), a regulator (pressure adjusting means) 14, an A / E converter 16, and an amplifier 18.

In the case of the jet 12 for measuring the inner diameter, the measuring head 20 is formed in a cylindrical shape. This measuring head 20
Are formed at equal intervals on the outer periphery of the tip of the air nozzle, and the four air nozzles 22, 22,.
... radially injects compressed air. At the time of measurement, the measuring head 20 is inserted into the hole 26 of the work 24, and compressed air is jetted from each of the air nozzles 22, 22,.

The compressed air injected from the air nozzles 22, 22, ... is supplied from an air source 28 to a third air pipe 30C, a regulator 14, a second air pipe 30B, an A / E converter 16,
Air nozzles 22, 22,... Via the first air pipe 30A.
Supplied to The regulator 14 adjusts the compressed air supplied from the air source 28 to a constant pressure, and the compressed air adjusted to the constant pressure is passed through a “throttle” installed in the A / E converter 16 to form an air nozzle. , 22, 22,... The A / E converter 16 includes the air nozzles 22, 2
The change in pressure (back pressure) between 2,... And the throttle is converted into a voltage signal by a built-in bellows and a differential transformer and output to the amplifier 18. The amplifier 18 displays the inner diameter of the work 24 on a built-in monitor based on the voltage signal.

By the way, the above air micrometer 10
Then, the compressed air supplied from the air source 28 is directly supplied to the jet 12 via the regulator 14 and the A / E converter 16.
Is supplied to the system. In the case of such a configuration, if a temperature change occurs in the compressed air supplied from the air source 28, an error due to temperature characteristics in the A / E converter 16 and thermal deformation of the jet 12 and the work 24 occur.

Therefore, in the air micrometer 10 of the present embodiment, the third air pipe 30C that connects the air source 28 and the regulator 14 is formed to be long. That is,
By making the third air pipe 30C long, the compressed air supplied from the air source 28 becomes equal to the room temperature while passing through the third air pipe 30C. Accordingly, a temperature characteristic error occurring in the A / E converter 16 and a thermal deformation occurring in the jet 12 and the work 24 can be suppressed, so that highly accurate measurement can be performed.

For the above purpose, the third air pipe 30
It is preferable that the length of C is set to a length sufficient for the compressed air supplied from the air source 28 to reach the same temperature as room temperature while passing through the third air pipe 30C.

The regulator 14 and the A / E converter 1
The length of the second air pipe 30B communicating with the air source 6 causes a decrease in the pressure of the compressed air, which in turn causes a decrease in measurement accuracy.
It is preferable that the third air pipe 30C that communicates with the regulator 14 is formed to be long.

FIG. 2 is a block diagram showing the configuration of a second embodiment of a back-pressure air micrometer for measuring the inner diameter to which the present invention is applied. As shown in FIG.
2, regulator 14, A / E converter 16 and amplifier 1
8 is the same as the air micrometer 10 of the first embodiment described above.

Air micrometer 4 of the second embodiment
0 denotes a temperature sensor (temperature detecting means) 42A to 42C and a temperature control unit (temperature control means) 4 to each of the air pipes 30A to 30C.
4A to 44C are provided. That is, in the first air pipe 30A, the first temperature sensor 42A is installed near the inlet of the jet 12, and the first temperature control unit 44A is installed upstream of the first temperature sensor 42A. In the second air pipe 30B, a second temperature sensor 42B is installed near the inlet of the A / E converter 16, and a second temperature control unit 44B is installed upstream of the second temperature sensor 42B. Have been. In the third air pipe 30C, a third temperature sensor 42C is installed near the inlet of the regulator 14, and a third temperature control unit 44C is installed upstream of the third temperature sensor 42C.

The operation of each of the temperature control units 44A to 44C is as follows.
Each of them is controlled by the control device 46.
Controls the temperature control units 44A to 44C based on the detection results of the temperature sensors 42A to 42C. That is, the control device 46 controls the air flowing through each of the air pipes 30A to 30C based on the detection results of the temperature sensors 42A to 42C,
Each of the temperature control units 44A to 44C is controlled so as to reach a preset temperature.

FIG. 3 is a plan view showing the structure of the first temperature control unit 44A. As shown in the figure, the first temperature control unit 44A includes a cooling unit 48A and a heating unit 50B.

The cooling section 48A cools the air flowing through the first air pipe 30A. The cooling section 48A includes a cooling coil 52A and a refrigerator 54A. Cooling coil 52
A is formed in a cylindrical shape, and a spiral flow path 52a is formed along the axis thereof. This cooling coil 52
A is supplied with a refrigerant cooled to a predetermined temperature by a refrigerator 54A by a pump 56A. Cooling coil 52
The refrigerant supplied to A exchanges heat with the air flowing through the first air pipe 30A while flowing through the spiral flow path 52a, and cools to a predetermined temperature. Then, it is returned to the refrigerator 54A.

On the other hand, the heating section 50A is connected to the first air pipe 30.
Heat the air flowing through A. The heating section 50A includes a heating coil 58A and a boiler 60A. The heating coil 58A is formed in a cylindrical shape similarly to the cooling coil 52A, and a spiral flow path 58a is formed along the axis thereof. The heating coil 58A includes the boiler 6
The heat medium heated to a predetermined temperature by 0A is pump 62A
Supplied by The heat medium supplied to the heating coil 58A is supplied to the first air pipe 3 while flowing through the spiral flow path 58a.
It exchanges heat with the air flowing through OA and heats it to a predetermined temperature. Then, it is returned to the boiler 60A.

The second temperature control unit 44B provided in the second air pipe 30B and the third temperature control unit 44C provided in the third air pipe 30C have the same configuration. Control device 4
6 drives and controls these temperature control units 44A to 44C to control the temperature of the air flowing through the air pipes 30A to 30C to a predetermined temperature.

The operation of the air micrometer according to the second embodiment configured as described above is as follows.

The compressed air supplied from the air source 28 is supplied to the third air pipe 30C, the regulator 14, the second air pipe 3
OB, the A / E converter 16, and the first air pipe 30A, and are jetted from the air nozzle 22 of the jet 12.

At this time, the temperature of the compressed air supplied from the air source 28 is detected by the third temperature sensor 42C immediately before being introduced into the regulator 14. The temperature detected by the third temperature sensor 42C is output to the control device 46, and the control device 46 controls the third temperature control unit 44C based on the detected temperature. That is, the regulator 1
The third temperature control unit 44C is controlled so that the temperature of the compressed air introduced into the unit 4 becomes a preset temperature.

The temperature of the compressed air adjusted to a constant pressure by the regulator 14 is detected by the second temperature sensor 42 B immediately before being introduced into the A / E converter 16, and the detected temperature is transmitted to the control device 46. Is output. Control device 46
Controls the second temperature control unit 44B based on the detected temperature. That is, the second air is supplied to the A / E converter 16 so that the temperature of the compressed air reaches a preset temperature.
The temperature control unit 44B is controlled.

Further, the temperature of the compressed air passed through the throttle by the A / E converter 16 is detected by the first temperature sensor 42A immediately before being introduced into the jet 12, and the detected temperature is output to the control device 46. Is done. The controller 46 controls the first temperature control unit 44A based on the detected temperature. That is, the compressed air introduced into the jet 12 is
The first temperature control unit 44A is controlled so as to reach a preset temperature.

As described above, by adjusting the temperature of the compressed air supplied from the air source 28 to always maintain a constant temperature, the temperature characteristic error of the A / E converter 16 caused by the change in the temperature of the supplied air, the jet 12, and the work 24 can be prevented from being thermally deformed, and highly accurate measurement can be performed.

In the above-described embodiment, the temperature control units 44A to 44C are installed in all the air pipes 30A to 30C, but may be installed in only one of the air pipes. Also, the first air pipe 30A and the second
You may make it install only in the air piping 30B, or only the 1st air piping 30A and the 3rd air piping 30C.
Since the A / E converter 16 is particularly susceptible to a change in temperature, the temperature control unit is preferably installed in an air pipe for compressed air introduced into the A / E converter 16.

Further, in the present embodiment, the temperature of the compressed air is adjusted to a preset temperature. However, the temperature of the room may be detected and adjusted to the same temperature as the room temperature.

The location of each of the temperature control units 44A to 44C is not particularly limited, and may be installed at a necessary place as necessary in consideration of the environment and the length of the air pipes 30A to 30C. Is preferred.

Further, the installation positions of the temperature sensors 42A to 42C are not particularly limited. For example, the temperature of the compressed air injected from the air nozzle 22 may be directly detected.

Further, the structure of the temperature control units 44A to 44C is not limited to that of the present embodiment, but various types can be used.

In the series of embodiments described above, the present invention has been described as an example in which the present invention is applied to an air micrometer for measuring an inner diameter. However, the present invention can be similarly applied to an air micrometer for measuring an outer diameter.

Also, in the above-described series of embodiments, the aperture is provided inside the A / E converter 16, but the aperture and the A / E converter are separated as shown in FIG. The present invention can also be applied to the air micrometer described above. In this air micrometer 70, compressed air injected from the air nozzle 22 of the jet 12 is supplied to an air source 28.
Through the regulator 14 and the aperture 72 to be divided into two parts. One is guided to the jet 12 and is ejected from the air nozzle 22, and the other is guided to the A / E converter 74. The A / E converter 74 converts the pressure change between the air nozzles 22, 22,... And the throttle 72 into a voltage signal using a built-in bellows and a differential transformer, and outputs the voltage signal to the amplifier 18. The amplifier 18 determines the work 2 based on the voltage signal.
4 is displayed on a built-in monitor.

The air micrometer 70 having such a configuration is described.
Also, by increasing the length of the air pipe 76 that communicates the air source 28 and the regulator 14, thermal deformation generated in the A / E converter 16, the jet 12, and the work 24 can be suppressed, and high precision Measurement can be performed.

Further, the air micrometer 70 having the above configuration
For example, by installing a temperature sensor 78 and a temperature control unit 80 between the regulator 14 and the throttle 72, the compressed air introduced into the A / E converter 16 and the jet 12 can be controlled to a predetermined temperature. Thereby, the temperature characteristic error of the A / E converter 16 and the jet 1
2. Highly accurate measurement can be performed while suppressing thermal deformation occurring in the work 24.

The above example is merely an example. For example, a temperature sensor 78 and a temperature control unit 80 may be installed between the throttle 72 and the jet 12, or the throttle 72 and the A / A
Temperature sensor 78 and temperature control unit 8 between E converter 74
0 may be set. Further, the temperature sensor 78 and the temperature control unit 80 may be provided between the air source 28 and the regulator 14, or the temperature sensor 78 and the temperature control unit 80 may be provided at all of these locations.

[0044]

As described above, according to the present invention, since the air supplied from the air source is always kept at a constant temperature, a temperature characteristic error of the air / electric converter caused by a change in the temperature of the supplied air. And thermal deformation of the jet and workpiece can be prevented, and high-precision measurement is always possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a back-pressure air micrometer for measuring an inner diameter to which the present invention is applied.

FIG. 2 is a block diagram showing the configuration of a second embodiment of a back-pressure air micrometer for measuring the inner diameter to which the present invention is applied.

FIG. 3 is a plan view showing a configuration of a temperature control unit.

FIG. 4 is a block diagram showing the configuration of another embodiment of a back-pressure air micrometer for measuring the inner diameter to which the present invention is applied.

[Description of Signs] 10 air micrometer, 12 jet, 14 regulator (pressure adjusting means), 16 A / E converter (air / electric conversion means), 18 amplifier, 20 measuring head, 22 ... Air nozzle, 24 ... Work, 26 ... Hole, 28
... Air source, 30A-30C ... Air pipe, 40 ... Air micrometer, 42A-42C ... Temperature sensor (temperature detection means), 44A-44C ... Temperature control unit (Temperature control means), 4
Reference numeral 6: control device, 70: air micrometer, 72: throttle, 74: A / E converter, 78: temperature sensor (temperature detecting means), 80: temperature control unit (temperature control means)

Claims (6)

[Claims] 1. An air micrometer in which air supplied from an air source is adjusted to a constant pressure by a pressure adjusting means and ejected from an air nozzle of a jet through a throttle to measure a dimension of a work. A length of a pipe connecting the air source and the pressure adjusting means is set so that air has the same temperature as room temperature while being introduced into the pressure adjusting means. Meter. 2. The air adjusted to a constant pressure by the pressure adjusting means is jetted from an air nozzle of a jet through a throttle, and a change in the back pressure of the air nozzle at that time is converted into an electric signal by an air / electric converter to convert the air into an electric signal. In an air micrometer for measuring dimensions, a temperature detecting means for detecting a temperature of air introduced into the air / electric converter, and provided upstream of the temperature detecting means and introduced into the air / electric converter. Temperature control means for adjusting the temperature of the air to be supplied, and control for controlling the temperature control means such that the temperature of the air introduced into the air / electric converter becomes a predetermined temperature based on the detection result of the temperature detection means. Air micrometer comprising: 3. The air conditioner according to claim 2, wherein the restrictor is installed in the air / electric converter, and the temperature control unit is installed between the pressure adjusting unit and the air / electric converter. The air micrometer according to claim 2, wherein 4. The air adjusted to a constant pressure by the pressure adjusting means is jetted from an air nozzle of a jet through a throttle, and a change in back pressure of the air nozzle at that time is converted into an electric signal by an air / electric converter to convert the air into an electric signal. In an air micrometer for measuring dimensions, a temperature detecting means for detecting a temperature of air jetted from the air nozzle; and a temperature provided upstream of the temperature detecting means for adjusting a temperature of air jetted from the air nozzle. Control means for controlling the temperature control means so that the temperature of the air jetted from the air nozzle becomes a predetermined temperature based on the detection result of the temperature detection means. Micrometer. 5. The air conditioner according to claim 1, wherein said throttle is installed in said air / electric converter, and said temperature control means is installed between said air / electric converter and said air nozzle. Item 7. An air micrometer according to Item 4. 6. An air micrometer for measuring the size of a workpiece by jetting air adjusted to a constant pressure by a pressure adjusting means through a throttle provided in an air / electric converter from an air nozzle of a jet, and jetting from the air nozzle. First temperature detecting means for detecting the temperature of the air to be supplied, and provided between the air / electric converter and the air nozzle, and provided upstream of the temperature detecting means;
First temperature adjusting means for adjusting the temperature of the air injected from the air nozzle; second temperature detecting means for detecting the temperature of the air introduced into the air / electric converter; A second temperature control means provided between the air / electrical converter and installed upstream of the temperature detecting means for adjusting the temperature of air introduced into the air / electrical converter; The first temperature control unit is controlled so that the temperature of the air injected from the air nozzle becomes a predetermined temperature based on the detection result of the detection unit, and the air / air ratio is controlled based on the detection result of the second temperature detection unit. Control means for controlling the second temperature control means so that the temperature of the air introduced into the electric converter becomes a predetermined temperature.