JPH062187U - Vibration type pressure measuring device - Google Patents

Abstract

(57) [Summary] [Objective] To provide a vibrating pressure measuring device capable of accurately setting the relative positions of a magnet and a vibrating beam. A vibrating pressure measuring device comprising: a vibrating beam provided on a diaphragm; and a DC magnetic field applying means for applying a DC magnetic field to the vibrating beam. A sensor chip made of silicon single crystal fixed to a support, and a diaphragm. A vibrating beam provided on the support, a spacer having one surface fixed to a support and provided around the sensor chip, a magnet provided to face the vibrating beam, a yoke for holding the magnet, and a yo-yo. -A yoke holder that holds the yoke, and a pipe made of a cylindrical shape memory alloy that has one end side fixed to the yoke holder and the other end side fixed to the support body to accurately set the relative position between the vibrating beam and the magnet. A vibrating pressure measuring device comprising a body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vibrating pressure measuring device capable of accurately setting a relative position between a magnet and a vibrating beam.

[0002]

[Prior art]

 FIG. 7 and FIG. 8 are explanatory views of a main part of a conventional example that has been generally used in the past. The title of the invention, "Method for manufacturing vibrating transducer", is shown in the application filed on July 2, 1987. 9 is a detailed view of a main part of FIG. 7, and FIG. 10 is a sectional view taken along line AA of FIG.

In the figure, 1 is a sensor chip made of a semiconductor single crystal. Reference numeral 2 denotes a measurement diaphragm formed by the recess 3 provided in the sensor chip 1 and receiving the measurement pressure Pm. Reference numeral 4 is a strain detection sensor embedded in the measurement diaphragm 2, and a vibrating beam is used. Reference numeral 5 denotes a shell made of a semiconductor epitaxial growth layer for sealing, which seals the vibrating beam 4 in the measurement diaphragm 3.

A vacuum chamber 6 is provided around the vibrating beam 4 and between the vibrating beam 4 and the measuring diaphragm 2 and the shell 5. The vibrating beam 4 is configured to oscillate by the natural vibration of the vibrating beam 4 by the magnetic field generated by the permanent magnet 7 and the closed loop self-excited vibration circuit (not shown) connected to the vibrating beam 4. There is. The permanent magnet 7 is arranged so as to face the vibrating beam 4 via a yoke 8, a yoke holder 9 and a spacer 11, and is provided by a screw 11 as shown in FIG. 7, or as shown in FIG. It is fixed to the support 14 by the adhesive 13.

In the above configuration, when the measurement pressure Pm is applied to the measurement diaphragm 2, the axial force of the vibrating beam 4 changes and the natural frequency changes, so that the measurement pressure Pm can be measured by the change of the oscillation frequency. .

[0006]

[Problems to be solved by the device]

 However, in such a device, (1) when screwing is used, at least two screws 12 are required. In addition, a clearance for inserting the screw 12 is required in the screw hole of the yoke holder 9, which deteriorates the positioning accuracy of the vibrating beam 4 and the permanent magnet 7 and deteriorates the output characteristics of the device. (2) When the adhesive 13 is used, the relative position between the vibrating beam 4 and the permanent magnet 7 changes due to aging, temperature change, etc., and the positioning accuracy deteriorates, and the output characteristics of the device deteriorate. .

The present invention solves this problem. An object of the present invention is to provide a vibrating pressure measuring device capable of accurately setting the relative positions of a magnet and a vibrating beam.

[0008]

[Means for Solving the Problems]

 In order to achieve this object, the present invention provides a vibrating pressure measuring device comprising a vibrating beam provided on a diaphragm and a DC magnetic field applying means for applying a DC magnetic field to the vibrating beam. A sensor chip made of a silicon single crystal, a diaphragm formed by a recess provided in the sensor chip to receive a measurement pressure, a vibrating beam provided in the diaphragm, and the sensor chip having one surface fixed to the support. A spacer provided in the surrounding area, a magnet provided to face the vibrating beam, a yoke for holding the magnet, a yoke holder for holding the yoke, and one end side A pipe body made of a cylindrical shape memory alloy, which is fixed to the yoke holder and the other end side of which is fixed to the support body and which accurately sets the relative position of the vibrating beam and the magnet. And a vibration type pressure measuring device.

[0009]

[Action]

 In the above configuration, when the measurement pressure is applied to the measurement diaphragm, the axial force of the vibrating beam changes and the natural frequency changes, so that the measurement pressure can be measured by changing the oscillation frequency. To assemble such a device, a sensor chip made of silicon single crystal is attached to a support. In this case, it may be attached to the support through an inclusion such as glass.

A spacer provided around the sensor chip is fixed to a support. The permanent magnet is arranged on the support through the yoke, the yoke holder, and the spacer. The pipe body is cooled to a temperature below the shape memory effect. Deform the inner diameter of the pipe so that it is larger than the outer diameter of the yoke holder, spacer, and support.

The yoke holder is inserted into one end of the pipe body, and then the spacer is inserted. Insert the other end of the pipe into the support. The yoke holder and spacer are fixed to one end of the pipe so that the pipe can be returned to a temperature above the shape memory effect and the relative position between the vibrating beam and the magnet can be set accurately. A support is fixed to the other end of the pipe body. Hereinafter, detailed description will be given based on examples.

[0012]

【Example】

 FIG. 1 is an explanatory view of the essential configuration of an embodiment of the present invention. In the figure, the same symbols as those in FIG. 7 represent the same functions. Only parts different from FIG. 7 will be described below. Reference numeral 21 is a pipe body made of a cylindrical shape memory alloy, one end of which is fixed to the yoke holder 9 and the other end of which is fixed to the support 14, and which accurately sets the relative position between the vibrating beam 4 and the magnet 7. is there. In this case, an alloy is used which, even if it is deformed in the martensite phase, when it becomes an austenite phase, it returns to the shape it had in austenite.

In the above configuration, when the measurement pressure Pm is applied to the measurement diaphragm 2, the axial force of the vibrating beam 4 changes and the natural frequency changes, so that the measurement pressure can be measured by the change of the oscillation frequency. To assemble such a device, as shown in FIG. 2, the sensor chip 1 made of a silicon single crystal is attached to the support body 14. In this case, it may be attached to the support through an inclusion such as glass.

A spacer 11 provided around the sensor chip 1 is fixed to a support 14. The permanent magnet 7 is arranged on the support 14 via the yoke 8, the yoke holder 9 and the spacer 11. As shown in FIG. 3, the pipe body 21 is cooled to a temperature below the shape memory effect. In this case, the pipe body 21 is immersed in the liquid nitrogen A.

As shown in FIG. 4, the inner diameter of the pipe body 21 is deformed so as to be larger than the outer diameters of the yoke holder 9, the spacer 11 and the support body 14. As shown in FIG. 5, the yoke holder 9 is inserted into one end of the pipe body 21, and then the spacer 11 is inserted. The other end of the pipe body 21 is inserted into the support body 14. A yoke holder 9 and a spacer 11 are provided at one end of the pipe body 21 so that the pipe body 21 can be returned to a temperature above the shape memory effect or higher and the relative positions of the vibrating beam 4 and the magnet 7 can be set accurately. Fix it. The support 14 is fixed to the other end of the pipe body 21.

As a result, the support body 14 and the yoke holder 9 are press-fitted and fixed to the pipe body 21, so that the pipe body between the pipe body 21 and the support body 14 or between the pipe body 21 and the yoke holder 9 is piped. Since there is no gap in the direction perpendicular to the axis of the body 21, the relative position between the support 14 and the yoke holder 9 can be accurately ensured. Therefore, the relative position of the vibrating beam 4 and the magnet 7 in the direction perpendicular to the axis of the pipe body 21 can be accurately set. Therefore, the output characteristics of the device can be improved and the accuracy of pressure measurement can be improved.

FIG. 6 is an explanatory view of a main part configuration of another embodiment of the present invention. In this embodiment, 31 is a tapered portion provided on the yoke holder 9. Reference numeral 32 is a groove provided in the support 14 for preventing slipping out. In the above structure, when there is a difference in the coefficient of thermal expansion between the yoke holder 9, the support body 14 and the pipe body 21, the pipe body 21, the yoke holder 9 and the pipe body 21 are affected by temperature changes. A difference between the coefficients of thermal expansion between the substrate and the support 14 causes shear stress.

This stress is relaxed by the superelasticity of the pipe body 21 itself, but when the frictional force between the yoke holder 9, the support body 14 and the pipe body 21 is lower than this stress, The relative positions of the yoke holder 9, the support body 14 and the pipe body 21 change. By providing the taper portion 31 and the groove 32 for preventing slipping out, the frictional force is improved, and a stable fixed state can be obtained for a long period of time against temperature changes.

[0019]

[Effect of device]

 As described above, the present invention is a vibrating pressure measuring device comprising a vibrating beam provided on a diaphragm and a DC magnetic field applying means for applying a DC magnetic field to the vibrating beam. A sensor chip made of silicon single crystal, a diaphragm formed by a recess provided in the sensor chip to receive a measurement pressure, a vibrating beam provided in the diaphragm, and the sensor chip having one surface fixed to the support. A spacer provided around the magnet, a magnet provided to face the vibrating beam, a yoke for holding the magnet, a yoke holder for holding the yoke, and one end side of the yoke. A pipe body made of a cylindrical shape memory alloy, which is fixed to the yoke holder and the other end side of which is fixed to the support, and which accurately sets the relative position of the vibrating beam and the magnet. Features A vibrating pressure measuring device was constructed.

As a result, the support body and the yoke holder are press-fitted and fixed to the pipe body, so that the pipe body and the support body or the pipe body and the yoke holder are disposed in a direction perpendicular to the axis of the pipe body. Since there is no gap, the relative position between the support and the yoke holder can be accurately ensured. Therefore, the relative position of the vibrating beam and the magnet in the direction perpendicular to the axis of the pipe body 21 can be accurately set. Therefore, the output characteristics of the device can be improved and the accuracy of pressure measurement can be improved.

Therefore, according to the present invention, it is possible to realize a vibrating pressure measuring device capable of accurately setting the relative positions of the magnet and the vibrating beam.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

2 is an explanatory view of an assembling process of the sensor chip 1, the yoke holder 9, the spacer 11 and the support 14 of FIG. 1. FIG.

FIG. 3 is an explanatory view of a cooling process of the pipe body 21 of FIG.

FIG. 4 is an explanatory view of a deformation process of the pipe body 21 of FIG.

5 is an explanatory view of an assembly process of the sensor chip 1, the yoke holder 9, the spacer 11, the support body 14 and the pipe body 21 of FIG.

FIG. 6 is an explanatory view of a main part configuration of another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a configuration of a conventional example that is generally used in the past.

FIG. 8 is a structural explanatory view of another conventional example that is generally used in the past.

9 is a detailed explanatory diagram of FIG. 7. FIG.

10 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 ... Sensor chip 2 ... Measuring diaphragm 3 ... Recessed portion 4 ... Vibrating beam 5 ... Shell 6 ... Vacuum chamber 7 ... Magnet 8 ... Yoke 9 ... Yoke holder 11 ... Spacer 14 ... Support 21 ... Pipe 31 ... Tapered portion 32 ... Groove prevention groove

Claims (1)

[Scope of utility model registration request] 1. A vibrating beam provided on a diaphragm, and a DC magnetic field applying means for applying a DC magnetic field to the vibrating beam.
In a vibrating pressure measuring device, a sensor chip made of silicon single crystal fixed to a support is used.
And a measuring pressure formed by a concave portion provided on the sensor chip.
A diaphragm for receiving the pressure, a vibrating beam provided on the diaphragm, and one surface fixed to the support body around the sensor chip.
A spacer provided, a magnet provided to face the vibrating beam, a yoke for holding the magnet, a yoke holder for holding the yoke, and one end side of the yoke holder. -Fixed to the other end of the support
It is fixed to the body and the relative position of the vibrating beam and the magnet is accurate.
With a pipe body made of a cylindrical shape memory alloy that is often set
An oscillating pressure measuring device characterized by being provided.