TWI454677B - Pressure sensing device and its sensing method - Google Patents

Description

Pressure sensing device and sensing method thereof

The present invention relates to a sensing device, and more particularly to a pressure sensing device and a sensing method thereof.

In general, the pressure sensing device such as a tire pressure, air pressure, and water pressure is usually measured by a pressure sensing device such as a U-tube pressure gauge or a Bourdon-tube gage.

The above-mentioned U-tube pressure gauge usually uses water or mercury as the standard liquid in the tube; when the U-shaped tube is open at both ends without pressure, the liquid levels of the two tubes are on the same level. If there is a pressure difference at both ends, the height of the liquid column will have a difference. The height difference of the liquid column can properly represent the pressure difference between the two ends of the U-tube, so as to measure the pressure of the pressure source.

Referring to FIG. 1 again, the Bouton pressure gauge 3 is formed by bending a copper alloy thin tube 90 having an elliptical cross section into a circular arc shape. One end of the copper alloy thin tube 90 is sealed and allows an active stretching space, and the other end thereof is provided. It is not closed and is welded to a pipe joint 92. When a gas or liquid pressure is introduced from the pipe joint 92, the bent pipe has a tendency to expand outward, and the end of the copper alloy thin pipe 90 is pulled via a link 94 to cause the hand-held sector gear 96 to swing. When the difference between the outer circumference and the inner circumference of the copper alloy thin tube 90 is equal to the elastic force of the elbow itself, the pointer 98 is fixed at a certain position of the dial, and the scale pointing thereto indicates the gas or liquid pressure.

However, the U-tube pressure gauge not only has a low precision of measurement, but most of the tubes used are made of glass materials, and are easily suspected of being broken and inconvenient to store; in addition, the inside of the U-tube pressure gauge Liquids often change volume due to temperature changes and lead to errors in measurement. The volume of the bend of the Bouton-type pressure gauge will also change with the temperature of the environment or the pressure source, and the bent pipe will be prone to metal fatigue after a certain number of stretches, which is easy to cause pressure measurement. The accuracy is reduced.

Therefore, the industry has developed a piezoelectric pressure sensing device to improve the shortcomings of the U-tube pressure gauge and the Bouton pressure gauge described above. The piezoelectric pressure sensing device is made of a piezoelectric material. When the piezoelectric material is squeezed by the pressure of the pressure source, the electric dipole moment in the piezoelectric material is shortened due to compression. In order to resist this change, the piezoelectric material generates positive and negative charges on the surface of the piezoelectric material to maintain the original state, thereby accurately calculating the pressure value of the pressure source by measuring the amount of positive and negative charges generated on the surface of the piezoelectric material.

However, the piezoelectric pressure sensing device described above can improve the low accuracy of the conventional pressure sensing device and the disadvantage of being susceptible to temperature, but the piezoelectric pressure sensing device directly applies pressure to the pressure source through the pressure source. The electrical pressure sensing device is prone to rust, moisture or damage after a period of use. In addition, in order to avoid the danger of electrical ignition, the piezoelectric pressure sensing device is not suitable for the pressure measurement of the flammable gas, so that the measurable field of the piezoelectric pressure sensing device is thus subject to limit. Therefore, it can be known from the above that the conventional pressure sensing device and the sensing method used therein are still not perfect, and there is still room for improvement.

In view of this, the main object of the present invention is to provide a pressure sensing device and a sensing method thereof, which not only have better accuracy in sensing, but also can be applied to various measurement fields.

In order to achieve the above object, the pressure sensing method provided by the present invention is for sensing the pressure of a pressure source, and the method comprises the following steps:

A. guiding the pressure of the pressure source to drive a magnetic member for generating a magnetic force to approach or away from a coil made of a conductive material;

B. Using the magnetic force change when the magnetic member moves, the coil generates a corresponding induced electromotive force.

C. Calculating the pressure change value of the pressure source by using the induced electromotive force to estimate the pressure value of the pressure source.

According to the above method, the present invention provides a pressure sensing device comprising a housing, a coil, a stretch film layer and a magnetic member. The housing has a detecting hole, one end of the detecting hole is in contact with the pressure source; the coil is made of a conductive material and is disposed on the housing; the elastic film layer is disposed in the housing And sealing the other end of the detecting hole and being stretched by the pressure of the pressure source; the magnetic member is disposed in the housing in a manner movable relative to the coil, and is connected to the stretch film layer.

Thereby, when the stretch film layer is stretched by the pressure of the pressure source through the detecting hole, the magnetic member is driven to move, so that the coil is affected by the magnetic force when the magnetic member moves to generate a corresponding induction. Electromotive force.

Further, in accordance with the above method, the present invention provides another pressure sensing device including a housing, a coil, and a magnetic member. Wherein, the housing has a detecting slot, the notch of the detecting slot is for contacting with the pressure source; the coil is made of a conductive material and is disposed on the housing; the magnetic member is capable of receiving the pressure The pressure of the source is pushed and moved in the detection slot relative to the movement of the coil.

Thereby, when the magnetic member is pushed by the pressure of the pressure source to move in the detecting groove, the coil is affected by the magnetic force when the magnetic member moves to generate a corresponding induced electromotive force.

According to the above concept, the pressure sensing device of the present invention further includes an arithmetic circuit electrically connected to the coil for receiving the induced electromotive force generated by the coil, and calculating the pressure value of the pressure source according to the induced electromotive force.

In order that the present invention may be more clearly described, the preferred embodiments are illustrated in the accompanying drawings.

Referring to FIG. 2, the pressure sensing device 1 of the first preferred embodiment of the present invention measures the pressure of a pressure source according to the pressure. In the present embodiment, the gas pressure in a gas tube 100 is measured, but not This is limited to this. The pressure sensing device 1 includes a housing 10, a coil 20, a stretch film layer 25, a magnetic member 30, a spring 35, an arithmetic circuit 40, and a display 45. among them:

The housing 10 includes a base 11, a cover 12 and a housing 13. The base 11 has a detecting hole 111, and one end of the detecting hole 111 is used to communicate with the gas pipe 100, so that gas in the gas pipe 100 can be guided into the casing 10 through the detecting hole 111. The cover 12 is disposed on the base, and the cover 12 has a main body 121 and an adjustment knob 122. The main body 121 has an accommodating space 1211 therein, and the main body 121 has a receiving space and a receiving space. 1211 is connected to the screw hole 1212; the adjustment knob 122 is disposed in the screw hole 1212. The outer casing 13 is overlaid on the cover 12 and shields the cover 12.

The coil 20 is made of a conductive material such as copper, iron, silver or the like. The coil 20 is disposed on the main body 121 of the cover 12 so as to surround the periphery of the accommodating space 1211.

The stretch film layer 25 is made of a material having a stretchable effect. The stretch film layer 25 is sleeved on the base 11 to seal the other end of the detecting hole 111. And it can be pushed by the gas pressure to extend in the direction of the accommodating space 1211.

The magnetic member 30 is configured to generate a magnetic force and is disposed in the accommodating space 1211 so as to be movable relative to the coil 20, and is connected to the layer of the stretch film 25. In addition, in the present embodiment, the magnetic member 30 is exemplified by a permanent magnet, but not limited thereto, and an electromagnet, a magnet, or other magnetic member having a magnetic force may be used instead.

The spring 35 is disposed in the accommodating space 1211. One end of the spring 35 is coupled to the adjusting knob 122 and the other end is coupled to the magnetic member 30 to adjust the position of the magnetic member 30 by rotating the adjusting knob 122 to push the spring 35.

The operation circuit 40 is disposed in the housing 10 and located between the cover 12 and the outer casing 13 and electrically connected to the coil 20 .

The display 45 is disposed on the outer casing 13 and electrically connected to the arithmetic circuit 40.

Therefore, referring to FIG. 3, the pressure sensing method used by the pressure sensing device 1 includes the following steps:

The use of the detecting hole 111 to guide the gas pressure to push the stretch film layer 25 to extend in the direction of the accommodating space 1211, thereby driving the magnetic member 30 to move relative to the coil 20 (as shown in FIG. 4), and in this step The moving amplitude of the magnetic member 30 is proportional to the instantaneous pressure change of the pressure source;

B. Using the magnetic force change when the magnetic member 30 moves, the coil 20 generates a corresponding induced electromotive force, and the induced electromotive force generated by the coil 20 in this step and the moving range of the magnetic member 30 in the step A. In proportion to

C. The operating circuit 40 receives the induced electromotive force generated by the coil 20, and uses the magnitude and direction of the induced electromotive force to calculate the displacement amount and the displacement direction of the magnetic member 30, and then uses the displacement amount to calculate the pressure change of the gas pressure. The value, in other words, when the coil 20 generates a predetermined induced electromotive force, indicates that the magnetic member 30 is displaced by a predetermined distance for a predetermined time, that is, the pressure of the gas pressure produces a change in a predetermined value. Thereby, the pressure value of the gas pressure can be calculated by the magnetic force change to generate the induced electromotive force, and displayed on the display 45.

In addition, the magnitude of the movement of the magnetic member 30 can be accurately sensed by the manner in which the induced electromotive force is generated by the magnetic force change, so that the pressure sensing device 1 of the present invention can accurately calculate the pressure value to be measured.

Furthermore, the present invention seals the design of the detecting hole 111 through the stretch film layer 25, so that the coil 20 having the electrical flow characteristics, the operating circuit 40, and the display 45 are separated from the pressure source to be measured. In order to achieve the effect of gas-electric separation or liquid-electric separation, the pressure sensing device 1 can be applied to the pressure measurement of ordinary gas and liquid, and can also be applied to the pressure of gas and liquid having flammable characteristics. Test, and achieve the purpose of being applicable to different measurement environments.

It should be noted that, in addition to the structure disclosed by the pressure sensing device 1 to achieve the object of the present invention, the present invention is directed to FIG. 5 and is a pressure sensing according to a second embodiment of the present invention. The device 2 can also be used to measure the gas pressure in the gas tube. The pressure sensing device 2 comprises a casing 50, a coil 60, a magnetic member 65, a spring 70, an arithmetic circuit 75 and a display 80. . among them:

The housing 50 includes a base 51 and a housing 52. The base 51 has a main body 511 and a adjusting knob 512. The main body 511 has a detecting slot 5111 communicating with the gas tube, and a screw hole 5112 communicating with the detecting slot 5111. The adjusting knob 512 is disposed on the main body 51. In the screw hole 5112. The outer casing 52 is overlaid on the base 51 and shields the base 51.

The coil 60 is disposed on the body 511 of the base 51 so as to surround the circumference of the detecting groove 5111.

The magnetic member 65 is configured to generate a magnetic force and is disposed in the detecting groove 5111 so as to be movable relative to the coil 60.

The spring 70 is disposed in the detecting groove 5111. One end of the spring 70 is coupled to the adjusting knob 512 and the other end is coupled to the magnetic member 65 to adjust the position of the magnetic member 65 by rotating the adjusting knob 512 to push the spring 70.

The operation circuit 75 is disposed in the housing 50 and located between the base 51 and the outer casing 52 and electrically connected to the coil 60.

The display 80 is disposed on the outer casing 52 and electrically connected to the arithmetic circuit 75.

Thereby, with the above arrangement, the pressure of the gas pressure can be used to push the magnetic member 65 in the detecting groove 5111 to move relative to the coil 60, and the magnetic force is changed when the magnetic member 65 is moved, so that the coil 60 is made. A corresponding induced electromotive force is generated; after the arithmetic circuit 75 receives the induced electromotive force generated by the coil 60, the result of the calculation can be displayed on the display 80 by the foregoing method.

Therefore, the pressure sensing device 2 of the present embodiment can not only achieve the above-mentioned precision measurement effect but also achieve the purpose of the above-mentioned gas-electric separation or liquid-electric separation, and the present embodiment can be achieved by using the closed groove design. The pressure sensing device 2 of the example is equally applicable to different measurement environments.

The above description is only a preferred embodiment of the present invention, and is not limited thereto. As long as the purpose of generating the induced electromotive force by utilizing the change of the magnetic force to achieve the side pressure is also an alternative embodiment of the present invention. The equivalent structure and manufacturing method variations of the specification and the scope of the application of the present invention are intended to be included in the scope of the invention.

1. . . Pressure sensing device

10. . . case

11. . . Pedestal

111. . . Probe hole

12. . . Cover

121. . . main body

1211. . . Housing space

1212. . . Screw hole

122. . . Adjustment knob

13. . . shell

20. . . Coil

25. . . Stretch film layer

30. . . Magnetic parts

35. . . spring

40. . . Operation circuit

45. . . monitor

2. . . Pressure sensing device

50. . . case

51. . . Pedestal

511. . . main body

5111. . . Detection slot

5112. . . Screw hole

512. . . Adjustment knob

52. . . shell

60. . . Coil

65. . . Magnetic parts

70. . . spring

75. . . Computing circuit

80. . . monitor

100. . . Gas tube

3. . . Bouton pressure gauge

90. . . Copper alloy thin tube

92. . . Pipe joint

94. . . link

96. . . Sector gear

98. . . pointer

FIG. 1 is a schematic view of a conventional Buton type pressure gauge.

Figure 2 is a structural view of a first preferred embodiment of the present invention.

3 is a flow chart of a pressure sensing method of the present invention.

Figure 4 is a schematic view of the first preferred embodiment of the present invention when sensing pressure.

Figure 5 is a structural view of a second preferred embodiment of the present invention.

1. . . Pressure sensing device

10. . . case

11. . . Pedestal

111. . . Probe hole

12. . . Cover

121. . . main body

1211. . . Housing space

1212. . . Screw hole

122. . . Adjustment knob

13. . . shell

20. . . Coil

25. . . Stretch film layer

30. . . Magnetic parts

35. . . spring

40. . . Operation circuit

45. . . monitor

Claims (16)

a pressure sensing device for sensing the pressure of a pressure source; the pressure sensing device comprises: a housing having a detecting hole, one end of the detecting hole is in contact with the pressure source; a coil, Is made of a conductive material and is disposed on the casing; a stretchable film layer is disposed in the casing and seals the other end of the detecting hole and can be stretched by the pressure of the pressure source; and a magnetic member is disposed in the housing in a manner movable relative to the coil and coupled to the stretch film layer; thereby, when the stretch film layer is pushed through the detecting hole and pushed by the pressure of the pressure source The magnetic member is driven to move, so that the coil is affected by the magnetic force when the magnetic member moves to generate a corresponding induced electromotive force. The pressure sensing device of claim 1 includes an arithmetic circuit electrically connected to the coil for receiving an induced electromotive force generated by the coil, and calculating a pressure value of the pressure source according to the induced electromotive force. The pressure sensing device of claim 2, further comprising a display electrically connected to the computing circuit for displaying the pressure value calculated by the computing circuit. The pressure sensing device of claim 1, comprising a spring having one end abutting the housing and the other end abutting the magnetic member; the stretch film layer being pushed by the pressure of the pressure source to stretch When the magnetic member is driven to move in the direction of the spring. The pressure sensing device of claim 4, wherein the housing comprises a base and a cover; the base is provided with the detecting hole; the cover is attached to the base, and the cover is The inside of the cover has an accommodating space; the magnetic member and the spring are disposed in the accommodating space. The pressure sensing device of claim 5, wherein the cover comprises a main body and an adjustment knob, the main body has the accommodating space and a screw hole communicating with the accommodating space; In the screw hole, and the end of the spring is abutted, and the spring is adjusted by rotating the adjustment knob to adjust the position of the magnetic member. a pressure sensing device for sensing the pressure of a pressure source; the pressure sensing device comprises: a housing having a detecting slot, the slot of the detecting slot is for contacting the pressure source; a coil Is made of a conductive material and disposed on the casing; a magnetic member is disposed in the detecting groove in such a manner as to be pushed by the pressure of the pressure source and moved relative to the coil; thereby, when the magnetic When the piece is pushed by the pressure of the pressure source to move in the detecting groove, the coil is affected by the magnetic force when the magnetic piece moves to generate a corresponding induced electromotive force. The pressure sensing device of claim 7, comprising an arithmetic circuit electrically connected to the coil for receiving an induced electromotive force generated by the coil, and calculating a pressure value of the pressure source according to the induced electromotive force. The pressure sensing device of claim 8, further comprising a display electrically connected to the computing circuit for displaying a pressure value calculated by the computing circuit. The pressure sensing device of claim 7, comprising a spring disposed in the detecting slot, and one end of the spring is in contact with the housing, and the other end is in contact with the magnetic member; the pressure source The pressure is pushed to move the magnetic member in the direction of the spring. The pressure sensing device of claim 10, wherein the housing further comprises an adjustment knob, and the bottom of the detection slot has a screw hole communicating with the detection slot; the adjustment knob is screwed to the screw The hole is in contact with the end of the spring, and the spring is adjusted by rotating the adjustment knob to adjust the position of the magnetic member. A pressure sensing method for sensing the pressure of a pressure source, the method comprising the following steps: A. guiding the pressure of the pressure source to drive a magnetic member for generating a magnetic force close to or away from a conductive material The coil is formed; B. The magnetic force changes when the magnetic member moves, so that the coil generates a corresponding induced electromotive force. The pressure sensing method of claim 12, wherein the magnitude of movement of the magnetic member in step A. is proportional to the instantaneous pressure change of the pressure source. The pressure sensing method of claim 13, wherein the induced electromotive force generated by the coil in step B. is proportional to the magnitude of movement of the magnetic member in step A. The pressure sensing method according to claim 12, further comprising a step C. after the step B, calculating the pressure change value of the pressure source by using the induced electromotive force to estimate the pressure value of the pressure source . The pressure sensing method according to claim 15, wherein in step C, the magnetic component is first used to calculate the displacement distance and direction of the magnetic component within a predetermined time by using the magnitude and direction of the induced electromotive force generated by the coil, and then the magnetic component is used. The pressure change value of the pressure source is derived by calculating the pressure change value of the pressure source within a predetermined time and the displacement value.