CN202141551U - Pressure transducer - Google Patents

Abstract

Provided is a pressure transducer possessing an empty casing, a cavity of which is from one side in connection with a fluid medium source output tube at an operation position; a Bourdon tube, a cavity of which is in connection with the cavity of the casing; a permanent magnet which is fastened to a termination end of the Bourdon tube; and a hall sensor which is assembled with the casing and arranged at a position with gaps relative to the magnet. The hall sensor is usually assembled with the casing through a support arm. Usually, one end of the arm is assembled with the casing through a cylindrical or elastic hinge, and the other end of the arm is in connection with a gap adjusting device between the permanent magnet and the hall sensor.

Description

Pressure transducer

Technical field

The utility model relates to a kind of structure that is used for the pressure transducer of liquid or gaseous fluid medium.This sensor can be used for the various driving control unit that are preferably small size low pressure (particularly vibration, piston, centrifugal and whirlpool) pump or compressor.

Background technology

Well-known is that the energy demand of pump or compressor consumption is regulated, and motor must cut out when the input of said pump or said compressor or output are plugged.Based on this reason, motor must be loaded onto the control module based on pressure transducer and switch usually.

This control module must be cheap as far as possible, also needs enough sensitive and reliable simultaneously.Very clear said characteristic at first must be that pressure transducer is intrinsic, because other element of control module all is can bear with obtainable.

Actual control module is equipped the piezoelectricity or the piezoresistance, pressure sensor of high sensitive and reliability usually, and it has at least companies up to a hundred to make.

For example, Honeywell Inc. has made the piezoresistance, pressure sensor based on four identical voltage dependent resistor (VDR)s, and these voltage dependent resistor (VDR)s are arranged in the groove on the silicon fiml and are connected to form bridge circuit.External pressure makes diaphragm deformation and produces Voltage unbalance, and this Voltage unbalance is measured by said bridge circuit.The numerical value of Voltage unbalance as useful signal and applied pressure be varied to direct proportion change [referring to A.Map г e л о в. " Д а т ч и к и Д а в л e н и я к о м п а н и и HONEYWELL "; The 7th phase of chip news (100), 2005; English: A.Margelov " Pressure sensorsof the HONEYWELL Company ", Chip News No.7 (100), 2005].

Clearly these sensors are very complicated and expensive.

Therefore, they are preferred for the part of the control module of expensive high pressure industrial pump or compressor, and their damage can cause serious consequence.

Therefore, it is desirable to the small size low-lift pump of family, home farm and the middle widespread use of enterprise's (for example repair service) on a small scale or the simpler and cheap pressure transducer of control module equipment of compressor.

But available data shows that this problem is still unresolved up to now.

Therefore, known a kind of cheap simple and easy-to-use variable resistor pressure transducer (referring to the website http/ of Ulyanovsk automobile plant/: uazremont.ru).It has hollow housing, and its cavity is connected to the efferent duct lubricating system of car engine (for example) of small size pump from a side, and at its opposite side by membrane sealed.This film has the push rod that is connected to rheostat arm kinematically, and rheostat arm is included in the circuit of regulating the permanent magnet position.This magnet has arrow, its indicated pressure graticule.In addition, said sensor is provided with the device of regulating said arrow initial position.

But the tracking pressure that this sensor can not be level and smooth changes, because rheostat is made by the nichrome electric wire with fixed thickness.Minimize wiring thickness and can reduce its reliability owing to quickening rheostatic wearing and tearing with the resolving power that increases affiliated sensor.

Also know pressure transducer, the sensor (referring to Ukraine utility model patent No.u200906151) of advising very much on its structure near hereinafter based on Bourdon tube.This sensor has:

The flow model housing, in the working position, its cavity is connected to the efferent duct of pump and is connected to input pipe from opposite side from a side;

Bourdon tube, its cavity is connected to the cavity of said housing;

Cylindrical solenoid, its ferromagnetic core rod motion is learned the clearing end that upward is connected to said Bourdon tube, and its coil is connected to suitable metering circuit (special, it will be embedded in the microcontroller able to programme of the control module of pump driver).

Any pressure that this sensor can track at the efferent duct of any high pressure (particularly automotive gear oil) pump smoothly changes.

Unfortunately, the said cylindrical solenoidal induction that is used for known sensor as the main signal that encourages said metering circuit changes the pressure variation that lags behind in the Bourdon tube, and this pressure changes the absolute value that is substantially equal to this pressure variation.In addition, the friction between solenoidal ferromagnetic plug and the coil has braking action equally.Therefore, the efficient of this known pressure sensor will be not enough when the major part of the control module that is used for any low-pressure pump or compressor.

Summary of the invention

Therefore, the target of the utility model is to create more " pressure sensors sensitive, the effective utilization in the control module of its suitable low-pressure pump or compressor.

This target solves through making like lower pressure sensor, and it has:

Hollow housing, in operating position, its cavity is connected to the efferent duct in the source of fluid media (medium) from a side;

Bourdon tube, its cavity is connected to the cavity of said housing,

Permanent magnet, its be fastened on the clearing end of Bourdon tube and

Hall element, itself and said housing assemble and are arranged on the position that has air gap with respect to said magnet.

This sensor can detect Bourdon tube because Hall element when work noninertia almost, so it can receive even very trickle pressure changes.

First supplementary features are that said Hall element is through sway brace and the assembling of said housing.It provides Hall element the accurate layout basic with respect to permanent magnet.

Second supplementary features are that an end of sway brace assembles with said housing through cylindrical or elastic hinge, and the other end of said sway brace is connected with the adjusting gear of said air gap between permanent magnet and Hall element.It is convenient to pressure place at the zero point adjustment Hall element in the Bourdon tube of definition.

Following to those skilled in the art content is clearly:

Each specific embodiment of the utility model can be manufactured to the combination in any of basic inventive concept and said supplementary features,

Based on the common technology means, the present invention's design can be replenished and/or is defined in the scope of claim, and

The preferred embodiment that the utility model is described does not limit the scope of right.

Description of drawings

Next the utility model is explained through describing the pressure transducer of proposing in detail with reference to the accompanying drawing that said sensor construction is shown.

Fig. 1 is the synoptic diagram that shows the structure of said sensor.

Embodiment

Pressure transducer has at least:

Hollow housing 1, in operating position, its cavity is connected to the efferent duct in the source (especially, pump or compressor) of unshowned working fluid or gaseous medium here from a side,

Bourdon tube 2, its cavity is connected to the cavity of said housing 1,

Permanent magnet 3, its be fastened on the clearing end of Bourdon tube 2 and

Hall element 4, itself and said housing 1 assemble and are arranged on the position that said relatively magnet 3 has air gap,

Expectation; If Hall element 4 is through sway brace 5 and said housing 1 assembling; And if an end of said arm 5 connects said housing 1 kinematically through suitable cylindrical or elastic hinge 6, and the other end of said arm 5 is installed with the adjusting gear 7 (for example screw) of the said air gap between permanent magnet 3 and Hall element 4.

In addition, said arm 5 is as the carrying person of connector 8, and connector 8 is doomed Hall element 4 is connected to unshowned suitable power supply and measurement loop commonly used here.

Above-mentioned pressure transducer is worked as follows.

When the pressure in the Bourdon tube 2 changed, the air gap value between the flexibility of this pipe 2 and Hall element 4 and the permanent magnet 3 changed equally.This causes the current/voltage value variation in direct ratio respectively in signal output place of Hall element 4.

The direction of this variation is confirmed with respect to the initial placement of Hall element 4 through the magnetic pole of main body magnet 3.This situation is expected when pressure transducer is adjusted in advance easily.

The initial voltage of the signal output of Hall element 4 must be set through the screw adjusting gear 7 of the air gap between permanent magnet 3 and Hall element 4, and the pressure in the Bourdon tube 2 of this initial voltage and setting is corresponding zero point.

Commercial Application

The pressure transducer of proposing can be easy to through the element manufacturing that is prone to obtain and as the equipment of the driving control unit of preferred small size low-lift pump and compressor.

Claims (3)

1. pressure transducer has:

Hollow housing, in operating position, its cavity is connected to the efferent duct of fluid medium source from a side;

Bourdon tube, its cavity is connected to the cavity of said housing;

Permanent magnet, it is fastened on the clearing end of Bourdon tube; With

Hall element, itself and said housing assemble and are arranged on the position that said relatively magnet has air gap.

2. pressure transducer as claimed in claim 1, wherein, said Hall element is through sway brace and the assembling of said housing.

3. pressure transducer as claimed in claim 2, wherein, an end of sway brace assembles with said housing through cylindrical or elastic hinge and the other end of said sway brace is connected with the adjusting gear of said air gap between permanent magnet and Hall element.