CN2432551Y

CN2432551Y - Non-displacement target type flow sensor

Info

Publication number: CN2432551Y
Application number: CN 00228912
Authority: CN
Inventors: 刘岩; 冯冠平; 敬刚; 金玉叶; 王德保
Original assignee: Shenzhen Research Institute Tsinghua University
Current assignee: Shenzhen Research Institute Tsinghua University
Priority date: 2000-07-21
Filing date: 2000-07-21
Publication date: 2001-05-30
Anticipated expiration: 2010-07-21

Abstract

The utility model discloses a non-displacement target type flow sensor in the technical field of testing. The non-displacement target type flow sensor comprises a piezoelectric resonance force sensor composed of piezoelectric crystals, a target rod, two fulcrum cutting edges, a metal diaphragm playing a sealing role, a sealing washer, a base plate playing a supporting role, a baffle plate, etc., wherein, one end of the target rod is a circular target surface. The non-displacement target type flow sensor has the purpose that the direct impact force of liquid in a pipe body to the circular target surface is converted in a non-displacement mode to the pressure of stress points of the piezoelectric resonance force sensor which is acted on the exterior of the pipe body and is composed of the piezoelectric crystals via the lever role played by the target rod; consequently, the fluid flow in the pipe body can be further measured.

Description

The non-displacement target-type flow sensor

The utility model belongs to technical field of measurement and test, further relates to a kind of non-displacement target-type flow sensor.

Flowmeter is one of instrument in the commercial measurement.Up to now, the kind of flowmeter reached kind more than 100 (the flow measurement engineering manual, [and U.S. ］ the R.W. Miller, China Machine Press).Target type meter is a kind of application flowmeter more widely wherein.The ultimate principle of target type meter is based on fluid target is directly impacted, front center at target, its pressure equals the dynamic pressure of fluid, and " swabbing effect " caused owing to forming " slough " vortex in the back side of target, reduces before the pressure at this place is undisturbed.Like this, just there is a pressure differential front and back of target, and this pressure differential causes an acting force to target surface.The size of this acting force is the major parameter of tolerance fluid flow.Target type meter is in the past all taked to measure the size of fluid to the target acting force based on the sensor of Displacement Measurement amount or deflection, and this class sensor is subjected to the restriction of technological and manufacturing level and manufacturing accuracy to the measuring accuracy of displacement and deflection, in batch process, be difficult to try to achieve a consensus, and later precision stability also is difficult to ensure.

It is a kind of not based on the principle of Displacement Measurement and distortion that the purpose of this utility model is to provide, and utilize the piezoelectric resonator force transducer of forming by piezoelectric crystal as base components, by rigid lever mechanism, with fluid to the dynamic pressure non-displacement of target be converted to the point pressure that acts on the piezoelectric resonator force transducer of forming by piezoelectric crystal, its measuring accuracy and stability are guaranteed by the character of piezoelectric crystal material itself, and then can measure the flow of fluid accurately.

The utility model comprises that one one end is the circular target surface that places fluid body inside, and the other end contacts with the piezoelectric resonator force transducer of being made up of piezoelectric crystal in the fluid hose external body, plays the target bar of leverage; With the edge of a knife form target bar cramp is held for two, the target bar is played the fulcrum edge of a knife of point action; The metallic membrane that seals, pad and compositions such as passive base plate, baffle plate.

The utility model will be further described below in conjunction with accompanying drawing.

Be connected with one side perforate of the body 8 of fluid, the hole of circular target surface end on body 8 walls of target bar 3 places in the body 8, and the circular plane of target bar 3 is vertical with fluid flow direction.Target bar 3 contacts with the stress point of the piezoelectric resonator force transducer of being made up of piezoelectric crystal 1 by a spheroid or cone 2 in the one side of an end of body 8 outsides, and by placing the spring 4 between baffle plate 9 and the target bar 3 that suitable pretightning force is provided.3 leverages of target bar, its fulcrum is opened the V-shaped groove place with 3 clampings of target bar by two fulcrum edges of a knife 7 on both sides, target bar 3 middle part, and two fulcrum edges of a knife 7 all are fixed on the lower surface of base plate 6 with screw fixation method.The outside surface of base plate 6 lower surfaces and body 8 gasket seal 11 of being separated by is closely fixing in the mode of uniform screw.Target bar 3 passes the mesopore of base plate 6, and is closely fixing by an end and 3 welding of target bar, and the other end and base plate 6 upper surfaces weld the mesopore sealing of closely fixing metallic membrane 5 with base plate 6, make body 8 inside and external isolation.The bottom surface installing and locating of piezoelectric resonator force transducer 1 is in baffle plate 10.

Principle of the present utility model be with body 8 inner fluids to the direct impulsive force of circular target surface through the leverage non-displacement of 3 on target bar be converted to the pressure that acts on piezoelectric resonator force transducer 1 stress point of forming by piezoelectric crystal body 8 outsides.

The utility model is applied to target type meter, and its essential characteristic is to use the piezoelectricity that is made up of piezo-electric crystal Resonant force sensor is as base components, and the target bar non-displacement ground by playing leverage is with body inner fluid pair The direct impulsive force of circular target surface is converted to the pressure that acts on the outside piezoelectric resonator power of body sensor stress point Power, and the interior outside of the body that the target bar passes is by metallic membrane and gasket seal isolating seal. Thereby can be further There is not the flow that leaks ground measuring tube inner fluid.

Claims

The target-type flow sensor of non-displacement, it comprise a piezoelectric resonator force transducer of forming by piezoelectric crystal, one wherein an end be to be subjected to the circular target surface of hydrodynamic pressure and the other end is the target bar of stress contact, two the fulcrum edges of a knife, the metallic membrane that seals, gasket seal and passive base plate, baffle plates etc. forms, it is characterized in that: the circular target surface end of target bar 3 places in the body 8, and target bar 3 contacts with the stress point of the piezoelectric resonator force transducer of being made up of piezoelectric crystal 1 by a spheroid or cone 2 in the one side of an end of body 8 outsides; Two fulcrum edges of a knife 7 are opened the V-shaped groove place with 3 clampings of target bar, as the fulcrum of target bar 3 on both sides, target bar 3 middle part; The closely fixing metallic membrane 5 of the other end and base plate 6 upper surfaces will the inside and outside isolation of body sealing by an end and target bar 3 is closely fixing.