CN2148321Y - High pressure isolation proportion transducer - Google Patents

Abstract

The utility model relates to a high pressure isolation proportion transducer, which is matched with a diffusion silicon force sensing transducer. A strain cylinder made of thin wall seamless steel tube with a minor caliber is sealed and arranged in a transducer casing which is made of seamless steel tube, and both ends of the transducer casing are respectively connected with a high voltage part to be measured and a silicon force sensing transducer. One end of the strain cylinder is connected with a through hole on the part with pressure to be measured. The other end of the strain cylinder is closed to lead the inner cavity of the cylinder and the inner cavity of the transducer to form two isolated spaces. A hollow cavity between the two isolated spaces is filled with pressure transmitting media. The high voltage is used for altering the volume of the strain cylinder to squeeze the pressure transmitting media to enter the silicon force sensing transducer to measure the pressure. The utility model has the advantages of simple structure, and has the functions of high-pressure isolation and protection.

Description

High pressure isolation proportion transducer

The utility model relates to a kind of supporting application apparatus of force-sensing sensor, belongs to the high-pressure separating ratio sensor of force sensor of diffused silicon.

Silicon-diffused force photosensitive elements stable performance, highly sensitive, sensor signal to noise ratio (S/N ratio) height, the linearity made with it are good, therefore, adopt the silicon-diffused force photosensitive elements to increase year by year, the posture of holding sway over a region in electromechanical integration pressure measuring instruments field is arranged greatly as the product of the sensitive element of the sensor of measuring various power.But because of the reason in processing technology and the structure manufacturing, the range ability of the silicon force-sensing parts of producing in batches is less now, can only use in the mesolow scope of 0.01～0.2 MPa (MPa).For this reason, the applicant is developed into a kind of range expander (patent No.: CN91200668.4) of force sensor of diffused silicon, utilize this device of two kinds of corrugated tubes formations of different-diameter and unlike material, can expand to the measurement range of the pressure transducer of above-mentioned mesolow range the high pressure range of 1～100 MPa.But the manufacture difficulty of the ratio coupling of two groups of corrugated tubes of former invention is bigger, and technological requirement is higher, and certain difficulty of processing is arranged.Especially after the pressure height arrives to a certain degree, even special instrument factory also is difficult to make.So just limited the application scenario of this invention.

The purpose of this utility model provides a kind of modifying device of former invention---high-pressure separating ratio sensor, carries out the high pressure measurement so that use the silicon force-sensing parts to substitute the high pressure corrugated tube again.

The utility model is matching used with force sensor of diffused silicon.By tubular shell, strain parts and link are formed.Wherein the tubular sensor housing is made with high voltage bearing weldless steel tube, its two ends are respectively equipped with the internal thread hole that is used to connect testing pressure position and silicon force sensitive sensor, also be sealedly connected with a strain tube made from the less weldless steel tube of bore at an end that connects the testing pressure position, one end of this strain tube is connected with the through hole at testing pressure position, the other end seals with plug, and the pressure transmitting medium that is full of in the cavity between sensor housing and the strain tube outer wall is a silicone oil.

The utility model remains with the corrugated tube that is full of silicone oil or other pressure transmitting media as the low pressure ratio pressure transmission element that is complementary with the silicon force-sensing parts, the high pressure corrugated tube that has just replaced foregoing invention with the strain tube of pipe shape, both are identical for its principle of work: after promptly being stressed by the high pressure strain tube, its volume change is and is become certain linear functional relation by measuring pressure, and the shell of sensor has pressure transmitting medium because of being full of between it and the strain tube, the volume change of sensor inner chamber is very little, has promptly dwindled according to certain ratio.Like this, just make difference in volume △ V between strain tube and the sensor inner chamber and tested high-pressure also be linear functional relation.Because volume dwindles the silicone oil of △ V by the crowded low pressure sensor that enters, measure the flexible member effect that corrugated tube (or pressure measurement bellows) constitutes by low pressure elasticity, the pressure that changes the pressure proportional that causes and silicon force-sensing parts because of the allergic effect cylindrical shell is long-pending is changed mate and be certain proportionate relationship, thereby play the range conversion, can measure high pressure.Calculate that in theory the pressure limit that the utility model is surveyed can be unrestricted, its range can be accomplished 10～100 MPas (MPa).From its principle of work as can be seen; the utility model also has isolates the gentle function of leaping high and pressing, so it also can be used as an annex with defencive function of sensor; and for high-precision sensor, this annex with safeguard function also is absolutely necessary.Moreover, though the utility model is a precision instrument accessory of measuring high pressure, but all parts that constitute this invention all have good rigidity and physical strength, and they can be used under suitable rugged environment and to keep its original characteristic constant, in a word, the utility model structure is very simple, the intensity height, long service life, applied widely, be the measuring range of expansion corrugated tube force-sensing sensor, be used to measure the more satisfactory corollary apparatus of high-pressure.

Fig. 1 is a structural representation of the present utility model.

1 is the sensor housing made from weldless steel tube among Fig. 1, its two ends are respectively internal thread holes, wherein an end 2(claims high pressure connection again) be used to connect high-pressure to be measured position, other end 3(claims again: low-pressure connector) be used to connect the silicon force sensitive sensor of mesolow range, at an end of high pressure connection 2 strain tube 4 made from the less weldless steel tube of bore that also is tightly connected.One end of this strain tube is connected with the through hole at testing pressure position, and the other end seals with plug 5, and making the cavity of strain tube 4 and the inner chamber of sensor outer housing 1 is two spaces that completely cut off.In the cavity between sensor housing 1 and strain tube 4 outer walls, be full of pressure transmitting medium.

Principle of work of the present utility model mainly is after utilizing the strain tube 4 that seals to be subjected to an interior fluid pressure (being the pressure at tested position), linearly proportional to the acting force that its barrel produces with the former, the variation of strain tube volume causes the pressure transmitting medium that is full of in the sensor shell intracoelomic cavity that respective change also takes place, and is delivered to the high-pressure numerical value that carries out matching ratio calculating in the silicon force sensitive sensor and obtain being measured again.As long as strain tube is stressed within the allowance strength scope of its constituent material, measuring accuracy of the present utility model all is quite high.But in order to guarantee the pressure proportional transmission better, the material of strain tube selects to consider its chemical stability, temperature drift and measuring repeatability, and factor such as material mechanical performance.Though sensor outer housing is not the mechanical elements of measuring, and for guaranteeing measuring accuracy, still should select material identical with strain tube and identical Technology for Heating Processing manufacturing, to guarantee the consistance of its physical property.

Though select beryllium-bronze or phosphor bronze usually for use at the instrument industry flexible member, but in the utility model, make strain tube and sensor outer housing if select stainless steel thin-wall type weldless steel tube for use, also can obtain pretty good result of use, and, use the latter also to have and reduce cost, good chemical stability is more suitable for the sensing element as the responsive acquisition system of computing machine.

In order to improve measuring accuracy, the cavity volume of sensor outer housing will be done as far as possible near the volume of (being slightly larger than) strain tube when the maximum working pressure (MOP).The sensor outer housing inner chamber can not be long with the kapillary that is communicated with between the corrugated tube, in order to avoid the pressure loss.The silicone oil that charges in the inner chamber must fully outgas through application of vacuum, and making must not have bubble in the sensor inner chamber.

Claims (2)

1, a kind of and the matching used high-pressure separating ratio sensor of force sensor of diffused silicon, include tubular shell, strain parts and link, it is characterized in that: the tubular sensor housing is made with high voltage bearing weldless steel tube, its two ends are respectively equipped with the internal thread hole that is used to connect testing pressure parts and silicon force sensitive sensor, also be sealedly connected with a strain tube made from the less thin-wall seamless steel pipe of bore at an end that connects the testing pressure position, one end of this strain tube is connected with the through hole at testing pressure position, the other end seals with plug, and the pressure transmitting medium that is full of in the cavity between sensor housing and the strain tube outer wall is a silicone oil.

2, by the described high-pressure separating ratio sensor of claim 1, it is characterized in that: sensor housing should adopt identical material with strain tube, same Technology for Heating Processing manufacturing.

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