CN209979119U

CN209979119U - Multichannel pressure transmitter adopting equal-pressure cavity

Info

Publication number: CN209979119U
Application number: CN201920962958.7U
Authority: CN
Inventors: 张燕亮; 张林伟; 张曙坚
Original assignee: Ningbo CRRC Times Transducer Technology Co Ltd
Current assignee: Ningbo CRRC Times Transducer Technology Co Ltd
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2020-01-21
Anticipated expiration: 2029-06-25

Abstract

The multichannel pressure transmitter adopting the equal-pressure cavity comprises a connector, an upper cover, a shell, a circuit board assembly, a pressure core body, a core body seat and a base; the middle of the core body seat is a cavity, the side surface of the cavity is sealed by a plurality of pressure core bodies and is connected with the core body seat to form an equal-pressure cavity, the sensing end of the pressure core body is positioned in the equal-pressure cavity, and the cavity is communicated with a base channel below through a connecting channel at the lower part, so that the equal-pressure cavity is communicated with a tested environment; the lower part of the core seat is fixed with the base; the circuit board assembly is fixed on the core body seat and is electrically connected with the pressure core body; the lower end of the shell is fixed with the base, the upper end of the shell is fixed with the upper cover, the connector assembly penetrates through the upper cover and is fixed on the upper cover, and the connector assembly is electrically connected with the pressure core body.

Description

Multichannel pressure transmitter adopting equal-pressure cavity

Technical Field

The utility model relates to a multichannel pressure transmitter especially relates to a multichannel pressure transmitter that track traffic monitored control system used.

Background

The pressure transmitter is a device which converts physical pressure parameters of gas, liquid and the like sensed by a load cell sensor into standard electric signals to be supplied to secondary instruments such as an indicating alarm instrument, a recorder, a regulator and the like for measurement, indication and process regulation.

The existing pressure transmitter generally comprises a shell, a base fixed at one end of the shell, a connector at the other end of the shell, a pressure core body positioned in the shell, and a signal processing circuit, wherein a power panel and a signal panel which are isolated from each other are arranged in the shell, the power panel and the signal panel are electrically connected through a flexible circuit board, the signal panel is electrically connected with the pressure core body, the signal panel is an integrated signal processing circuit, a conditioning chip in the signal processing circuit is used for processing a pressure signal detected by the pressure core body, and the processed signal is output through the connector. However, the conventional pressure transmitter has the following disadvantages.

1. One pressure transmitter can only provide one path of signals, if a system needs to be designed for signal redundancy, the number of the pressure transmitters must be increased, so that the number of interfaces on a pressure pipeline is increased, the leakage risk is increased, the wiring is multiplied, and the space is occupied; and the installation conditions of the pressure transmitters are not completely the same, so that pressure difference exists among the pressure transmitters, and system signal sampling is influenced.

2. The casing assembly needs screw fastening, still needs the sealed of sealing member holding between the casing, and the part quantity is many, and manufacturing procedure is complicated, and the reliability is low.

Disclosure of Invention

The utility model aims to solve the technical problem that overcome the above-mentioned not enough of prior art and provide an adopt multichannel pressure transmitter in isobaric chamber, make it can carry out multichannel measurement.

The utility model provides a technical scheme that above-mentioned problem adopted does: the multichannel pressure transmitter adopting the equal-pressure cavity comprises a connector, an upper cover, a shell, a circuit board assembly, a pressure core body, a core body seat and a base; the middle of the core body seat is a cavity, the side surface of the cavity is sealed by a plurality of pressure core bodies and is connected with the core body seat to form an equal-pressure cavity, the sensing end of the pressure core body is positioned in the equal-pressure cavity, and the cavity is communicated with a base channel below through a connecting channel at the lower part, so that the equal-pressure cavity is communicated with a tested environment; the lower part of the core seat is fixed with the base; the circuit board assembly is fixed on the core body seat and is electrically connected with the pressure core body; the lower end of the shell is fixed with the base, the upper end of the shell is fixed with the upper cover, the connector assembly penetrates through the upper cover and is fixed on the upper cover, and the connector assembly is electrically connected with the pressure core body.

Preferably, the pressure cores are uniformly distributed along the circumference of the cavity, and the arrangement is more reasonable.

Better, core seat lower extreme processing laser welding face of cylinder, excircle fitting surface and external screw thread, the base that corresponds has laser welding face of cylinder, interior fitting surface and internal thread, makes the laser welding face of cylinder align between core seat and the base through inside and outside fitting surface, through screw pretension, makes the welding position of core seat and base paste tightly, can satisfy the requirement of laser welding butt weld gap like this.

Preferably, two sides of the upper end of the core seat are respectively provided with the fixing lugs, the printed board of the circuit board assembly is provided with a groove, the printed board is inserted into the upper end of the core seat through the groove and is fixed on the core seat by leaning against the fixing lugs, so that the printed board can be supported by the core seat, can be better limited and fixed by the upper end of the core seat and the two fixing lugs, and can be prevented from shaking.

Preferably, the circuit board assembly is electrically connected to the pressure core by flexible printed wiring.

Preferably, the connector assembly is mounted on the cover and is connected to the circuit board assembly by flexible printed conductors.

Preferably, the connector assembly comprises a connector, a fastener and a sealing piece, the inner side of the connector is clamped by the fastener, and the sealing piece is arranged on the outer joint surface for sealing, so that the connector assembly can be fixed more firmly and is better sealed.

Better, processing circular recess on the base, waterproof ventilated membrane is placed in the recess, and the vertical hole is opened at the recess center to communicate with the horizontal cell type blow vent in outside, with prevent that outside aqueous vapor from getting into, can prevent ponding and deposition, avoid causing the blow vent to block up, avoid external foreign matter to cause the ventilated membrane to damage like iron wire direct contact waterproof ventilated membrane.

Preferably, the core body seat and the pressure core body are welded by laser, so that sealing is realized while connection is realized, leakage caused by a sealing element is eliminated, and reliability is high; meanwhile, the core body is hardly affected by laser welding, the problem of pressure signal drift caused by assembly stress can not occur after long-term application, and the product stability is high.

Preferably, the shell, the upper cover and the base are welded by laser, so that the production process is simplified, the number of parts is reduced, and the manufacturing efficiency is improved.

Compared with the prior art, the utility model has the advantages of: the constant-pressure cavity is adopted to connect a plurality of pressure cores, so that pressure sources measured by the plurality of pressure cores are always kept consistent, multi-path pressure signals can be output simultaneously under the condition that an original pressure transmitter mounting interface is unchanged, and the pressure difference caused by different pressure medium sampling points among the multi-path pressure signals is eliminated. And the pressure core body is connected on the core body seat through the side, has solved the difficult problem of multichannel measurement in narrow and small space, has saved the space of product, can expand into the measurement of many ways.

Drawings

Fig. 1 is an exploded view of a multi-channel pressure transmitter employing an isobaric chamber according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram between the base, the core seat, the pressure core, and the circuit board assembly of the multi-channel pressure transmitter using the equal-pressure cavity according to the embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a multi-channel pressure transmitter using an equal-pressure cavity according to an embodiment of the present invention.

Fig. 4 is a side cross-sectional view of a multi-channel pressure transmitter employing an isobaric chamber according to an embodiment of the present invention.

Fig. 5 is a perspective view of a partial cross-section of a base band of a multi-channel pressure transmitter employing an isobaric chamber according to an embodiment of the present invention.

Fig. 6 is a matching diagram of the base and the pressure core of the multi-channel pressure transmitter using the equal-pressure cavity according to the embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view of the base, the core seat and the pressure core according to another embodiment of the present invention.

Fig. 8 is a perspective view of the base, core seat and pressure core of another embodiment of the present invention.

Fig. 9 is a signal processing circuit of the multi-channel pressure transmitter using the isobaric cavity according to the embodiment of the present invention.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

Example 1

As shown in fig. 1 to 6, the two-channel pressure transmitter using an equal-pressure chamber includes a connector 1, an upper cover 3, a housing 6, a circuit board assembly 7 (circuit components are not shown), a pressure core 9, a core seat 10, and a base 11.

The middle of the core body seat 10 is a cavity 101, two side surfaces of the core body seat are sealed by two pressure core bodies 9 and welded together through laser to form an equal-pressure cavity, and the sensing ends of the pressure core bodies are positioned in the equal-pressure cavity, so that pressure sources measured by the two pressure core bodies 9 are always kept consistent.

The cavity 101 communicates with the lower base 11 channel 110 through the lower connecting channel 102, so that the constant pressure cavity 101 communicates with the measured environment.

The joining surfaces of the base 11 and the core body holder 10 are fixed together by laser welding.

Preferably, the lower end of the core seat 10 is provided with a laser welding cylindrical surface 103, an outer circle matching surface 104 and an external thread 105, the corresponding base 11 is provided with a laser welding cylindrical surface 111, an inner circle matching surface 112 and an internal thread 113, the laser welding cylindrical surfaces between the core seat 10 and the base 11 are aligned through the inner circle matching surface and the outer circle matching surface, and the welding parts of the core seat 10 and the base 11 are tightly attached through thread pre-tightening, so that the requirement of laser welding on a welding seam gap can be met, and the requirement is shown in fig. 5 and 6.

Two sides of core seat 10 upper end set up fixed ear 106 respectively, the printing board of circuit board subassembly 7 sets up recess 72, and the printing board inserts through recess 72 core seat 10 upper end to lean on fixed ear 106, rethread screw 13, bullet pad 14, flat pad 15 install on core seat 10, and the printing board can be spacing and fixed by core seat 10 upper end and two fixed ears 106 better like this, prevents that the printing board from rocking, guarantees its reliability.

The printed board is also electrically connected to two pressure cores 9 and the connector 1 by flexible printed

conductors

5, 8, respectively.

The circuit board assembly 7 is provided with a plurality of independent sensor signal processing circuits and a power supply protection circuit, the signal processing circuits amplify, perform temperature compensation and nonlinear compensation on output signals of the pressure sensors and convert the output signals into standard signals for output, and the power supply protection circuit realizes reverse connection prevention and inhibits interference such as surge, pulse group, conduction, radiation and the like. The circuit is a conventional pressure transmitter signal processing circuit, the specific circuit of the embodiment is shown in fig. 9, and L1 and L2 at the front end of the power supply part are inductors, so that high-frequency common-mode interference is suppressed. C1 filters the input power; v1 is that the TVS tube suppresses the interference of surge, pulse group and the like to protect the back end circuit; v2 plays a role in preventing reverse connection for the diode; the V3 is a V/I conversion transistor which can amplify the output current. V4 is the MOS pipe, as the voltage control pipe, uses through carrying out parameter setting to the chip with intelligent regulation chip cooperation and can make under the circumstances of excessive pressure play the steady voltage effect and carry out overvoltage protection and make the output not receive the influence of power overvoltage to the chip, and N1 is for regulating the chip, can carry out digital compensation skew, sensitivity, temperature drift and nonlinearity to the sensor. V5 is Zener tube to prevent high voltage between VDDA and GND from burning out chip; r4, R5, C6, C7 and C8 form an RC filter circuit to filter the common-mode signal and the differential-mode signal of the output of the pressure sensor. R2 is the Vbe voltage adjusting tube, and triode output maximum power descends along with the temperature rise, and R2 can divide the voltage with the triode by taking a proper resistance value, so that the voltage drop among the triodes Vce is reduced, and the power consumption of the triode is reduced. V6 is a diode, and the external temperature diode of intelligent conditioning chip N1 is used as the characteristic of diode PN junction temperature.

The connector 1 penetrates through the upper cover 3, the inner side of the connector 1 is clamped by a mounting fastener 4, and a sealing piece 2 is arranged on the joint surface of the outer side of the connector 1 for sealing.

A circular groove 114 is formed on the base 11, and the waterproof breathable film 12 is placed in the groove 114 to prevent external moisture from entering, see fig. 1 and 5.

The vertical hole 115 is formed in the center of the groove and is communicated with the outer transverse groove type air vent 116, external foreign matters can be prevented from directly contacting the waterproof breathable film 12 by the structure, and the groove type air vent 116 can prevent water accumulation and dust deposition and avoid blocking the air vent.

The two ends of the shell 6 are respectively welded with the base 11 and the upper cover 3 through laser to form a firm structure, and the connecting part has air tightness.

Example 2

As shown in fig. 7 and 8, the 4-channel pressure transmitter using the constant-pressure chamber differs from embodiment 1 only in the structure of the core holder 10 and the number of pressure cores 9 and the number of corresponding signal processing circuits.

In this embodiment, the core holder 10 is divided into two layers, an upper layer and a lower layer, the middle is a cavity, and the cavity between the upper layer and the lower layer is communicated.

In this embodiment, there are 4 pressure cores 9 respectively disposed at two sides of the cavity of the upper and lower layers of the core seat 10, and each pressure core 9 is electrically connected to the printed circuit assembly through the flexible printed wire 8.

Claims

1. Adopt multichannel pressure transmitter in constant pressure chamber, its characterized in that: the circuit board assembly comprises a connector, an upper cover, a shell, a circuit board assembly, a pressure core body, a core body seat and a base; the middle of the core body seat is a cavity, the side surface of the cavity is sealed by a plurality of pressure core bodies and is connected with the core body seat to form an equal-pressure cavity, the sensing end of the pressure core body is positioned in the equal-pressure cavity, and the cavity is communicated with a base channel below through a connecting channel at the lower part, so that the equal-pressure cavity is communicated with a tested environment; the lower part of the core seat is fixed with the base; the circuit board assembly is fixed on the core body seat and is electrically connected with the pressure core body; the lower end of the shell is fixed with the base, the upper end of the shell is fixed with the upper cover, the connector assembly penetrates through the upper cover and is fixed on the upper cover, and the connector assembly is electrically connected with the pressure core body.

2. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the lower end of the core body seat is provided with a laser welding cylindrical surface, an outer circle matching surface and an external thread, the corresponding base is provided with the laser welding cylindrical surface, an inner circle matching surface and an internal thread, the laser welding cylindrical surface between the core body seat and the base is aligned through the inner circle matching surface and the outer circle matching surface, and the welding parts of the core body seat and the base are tightly attached through thread pre-tightening.

3. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the two sides of the upper end of the core body seat are respectively provided with a fixing lug, the printed board of the circuit board assembly is provided with a groove, and the printed board is inserted into the upper end of the core body seat through the groove and leans against the fixing lug to be fixed on the core body seat.

4. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the circuit board assembly is electrically connected with the pressure core body through a flexible printed conductor.

5. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the circular groove is processed on the base, the waterproof breathable film is placed in the groove, and the vertical hole is formed in the center of the groove and communicated with the outer transverse groove type vent hole.

6. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the connector assembly is mounted on the upper cover and connected to the circuit board assembly by flexible printed conductors.

7. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the connector assembly comprises a connector, a fastener and a sealing element, wherein the inner side of the connector is clamped by the fastener, and the sealing element is arranged on the joint surface of the outer side of the connector for sealing.

8. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the pressure cores are uniformly distributed along the circumference of the cavity.

9. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the core body seat and the pressure core body are welded by laser.

10. The multi-channel pressure transmitter using an equal-pressure cavity according to claim 1, characterized in that: the shell, the upper cover and the base are welded by laser.