CN104964721A - Air flow channel structure of air flow meter - Google Patents
Air flow channel structure of air flow meter Download PDFInfo
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- CN104964721A CN104964721A CN201510385785.3A CN201510385785A CN104964721A CN 104964721 A CN104964721 A CN 104964721A CN 201510385785 A CN201510385785 A CN 201510385785A CN 104964721 A CN104964721 A CN 104964721A
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Abstract
The invention provides an air flow channel structure of an air flow meter. The structure comprises a base body and a top cover, and the top cover is buckled to the base body. The base body is provided with an air inlet, an air outlet, a flow dividing channel and a measuring channel, wherein the air inlet and the air outlet are opposite in position, the flow dividing channel and the measuring channel are both communicated with the air inlet and the air outlet, and the flow dividing channel and the measuring channel are separated through a central protrusion. Each of two sides of the air inlet is provided with a chamfer so that the air inlet can be smoothly expanded outwards to be in the shape of a horn. After air entering from the air inlet is divided through a flow dividing tip of the central protrusion, part of the air enters the flow dividing channel, and the other part of the air enters the measuring channel; the flow dividing channel corresponds to the linear segment position of the central protrusion, and the air entering the flow dividing channel is gradually shrunk to the air outlet along the straight side walls on the two sides of the flow dividing channel from the upstream portion to the downstream portion. The air flow channel structure is specially designed, and therefore the measurement result of the air flow meter with the air flow channel structure can be more accurate, and when air flow speed changes, the high and low speed measurement sensitivity of the air flow meter is more balanced.
Description
Technical field
The invention belongs to auto-parts field, be specifically related to a kind of gas flow structure of air flowmeter.
Background technology
Along with the raising required engine automobile exhaust emissions, increasing engine adopts accurate air flowmeter to be metered into the air capacity of engine, Engine ECU is according to the basic fuel delivery of air flow meter signal initial setting, to meet the various operating mode air-fuel ratio of engine, and then ensure that the various operating mode of engine is to the requirement of combination gas.
Thermal air flowmeter is the one in air flowmeter, its be utilize the pyrogen in air-flow and between tested air heat exchange relationship to measure a kind of sensor of current MAF.Its principle of work is: be placed on by heater element in the middle of air-flow, its surface and air generation heat interchange, detected by sensor circuit some parameter to heat interchange, and obtain the gas flow near heater element, thus extrapolate the gas flow of whole pipeline.
Thermal air flowmeter generally comprises supporter and measuring sensor, and described supporter is arranged on the sidewall of such as engine suction pipeline, and has the gas flow structure that supplied gas passes through; Described measuring sensor comprises a sensor, and for detecting the change of air-flow, it measures air mass flow by the temperature variation of the sensor surface caused by the change of air-flow velocity.Because sensor relies on detection heater element and air draught to carry out heat interchange degree to judge air flow rate, therefore the flow state of inlet air can have larger impact to the measurement result of sensor.
Generally all there is such problem when carrying out flow measurement in current thermal air flowmeter, namely when air velocity is lower, air mass flow is less, and the sensitivity of sensor detection fluctuations in discharge is higher; And when air velocity is higher, air mass flow is comparatively large, the sensitivity of sensor detection fluctuations in discharge is relatively low.Therefore this air flowmeter is when air velocity changes, unbalanced because of high low speed measurement sensistivity, can affect measuring accuracy.
Summary of the invention
The present invention is directed to above-mentioned the deficiencies in the prior art, provide a kind of gas flow structure that can make the air flowmeter that the sensitivity of air flowmeter is more balanced, accuracy of measurement is higher.
The present invention is achieved through the following technical solutions:
A gas flow structure for air flowmeter, comprises matrix and top cover, and described top cover is fastened on matrix and forms described gas flow structure;
It is characterized in that: described matrix is provided with the relative air intake opening in position and gas outlet, and the split channel be all communicated with air intake opening and gas outlet and Measurement channel, described split channel and Measurement channel are separated by a central protuberance;
The circumference of described central protuberance comprises a straight-line segment, an entrance curve section, measures arc section and an exit curve, the junction of described straight-line segment and entrance curve section forms one and shunts tip, and straight-line segment and measurement arc section are linked together by the transition of S type by described entrance curve section; Measurement arc section and straight-line segment are linked together by the transition of S type by described exit curve, and the junction of described exit curve and straight-line segment forms one and to conflux tip;
The both sides of described air intake opening are provided with chamfering, such that air intake opening is round and smooth to be extended out in horn-like; The gas entered by air intake opening is after the shunting tip shunting of central protuberance, and a part enters split channel, and another part enters Measurement channel; Described split channel is corresponding with the straight-line segment position of central protuberance, and the gas entering split channel is gradually contracted to gas outlet from upstream to downstream along the straight sidewall of split channel both sides.
Preferably, described Measurement channel comprises the horizontal flow channel be communicated with successively, longitudinal main channel and horizontal flow pass;
Described horizontal flow channel corresponds to the entrance curve fragment position of central protuberance, and described horizontal flow pass corresponds to the exit curve fragment position of central protuberance;
Measurement arc section protruding centered by a sidewall of described longitudinal main channel, another sidewall is provided with a curved surface consistent, towards the opposite with described measurement arc section radian, the centre position of described curved surface is provided with a breach, and described breach is for inserting sensor chip;
The bottom surface of described longitudinal main channel is provided with a rising step, between described rising step and bottom surface, passes through sloped transition; Position corresponding with rising step on described top cover is provided with a decline step identical with upgrade platform stage structure; Gap is left between the bottom of described breach and rising step;
The structure of described Measurement channel makes, after top cover fastens, to enter the gas of Measurement channel first along the curvilinear sidewall of horizontal flow channel both sides, and what maintenance cross-sectional area was constant flow to longitudinal main channel; Afterwards in longitudinal main channel owing to measuring the restriction of arc section, curved surface, rising step and decline step, make the gas that enters at left and right directions and above-below direction from large to small all first, that changes from small to big flow to horizontal flow pass again, and along the curvilinear sidewall of horizontal flow pass both sides, keep cross-sectional area constant flow to gas outlet; Outflow is converged in gas outlet through split channel and Measurement channel.
Preferably, the bottom surface of described Measurement channel offers a through hole, on described top cover, corresponding position also offers a through hole, measure-alike, the central axes of two through holes.
The present invention has following beneficial effect:
1, the present invention has carried out particular design to from gas flow structure, first extraneous gas enters from horn-like air intake opening, two-way is split into through shunting tip, wherein a bend folds into into horizontal flow channel, horizontal flow channel is provided with curvilinear sidewall, effectively can guide gas, chaotic gas is tended towards stability gradually; Gas bending afterwards enters longitudinal main channel, and longitudinal main channel has approximate Double bell-mouth structure of air, first can compress amplify gas, flows out finally by the curvilinear sidewall by horizontal flow pass; This kind of structure makes the gas stabilization of flows through sensor chip position better, and then makes the measurement result of air flowmeter more accurate.
2, the gas distribution entered is become two-way by shunting is most advanced and sophisticated by gas flow structure of the present invention, and when gas flow rate is lower, the air-flow ratio of split channel and Measurement channel is probably 2: 8; When gas flow rate is higher, the gas of split channel flows out fast, the space of surrounding is made to form certain negative pressure, thus the gas ratio entering Measurement channel is increased, air-flow ratio through measuring split channel and Measurement channel can rise to 3: 7 by 2: 8, thus making when air velocity is higher, the sensitivity of sensor chip detection fluctuations in discharge improves.
3, the breach of gas flow structure of the present invention by arranging on the curved surface of longitudinal main channel for inserting sensor chip; and certain interval is left between the bottom of breach and rising step; dust can be flow through from bottom gap; prevent the impurity such as dust and sensor chip surface from colliding; play the effect of protection sensor chip and filtration, thus make measurement data more accurate.
4, the gas distribution entered is become two-way by shunting is most advanced and sophisticated by gas flow structure of the present invention, and this shunting arranges and can stop that large particulate matter enters Measurement channel, can provide better working environment for sensor chip.
Accompanying drawing explanation
Fig. 1 is the structural drawing of described gas flow structure;
Fig. 2 is the structural drawing insert sensor chip in matrix after;
Fig. 3 is the structural drawing of matrix;
Fig. 4 is the structural drawing of top cover;
In figure, the implication of each label is as follows:
Matrix 1, top cover 2, air intake opening 3, gas outlet 4, split channel 5, Measurement channel 6, central protuberance 7, sensor chip 8, through hole 9, horizontal flow channel 61, longitudinal main channel 62, horizontal flow pass 63, curved surface 64, rising step 65, decline step 66, straight-line segment 71, entrance curve section 72, measurement arc section 73, exit curve 74, shunting tip 75, tip 76 of confluxing.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention will be further described in detail.
As Figure 1-4, the invention provides a kind of gas flow structure of air flowmeter, comprise matrix 1 and top cover 2, described top cover 2 is fastened on matrix 1 and forms described gas flow structure; Matrix 1 and top cover 2 can be split-type structural, also can be integral structures.
This gas flow structure is used in air flowmeter, and when air flows through this gas flow structure, the sensor chip be placed in this gas flow structure can detect some parameter, thus calculate the air mass flow of whole pipeline.
The present invention only improves for gas flow structure, and this gas flow structure, except may be used for air flowmeter, can also be used for any sensor device having fluid media (medium) to flow through.
Described matrix 1 is provided with the relative air intake opening in position 3 and gas outlet 4, and the split channel 5 be all communicated with air intake opening 3 and gas outlet 4 and Measurement channel 6, described split channel 5 and Measurement channel 6 are separated by a central protuberance 7;
The circumference of described central protuberance 7 comprises straight-line segment 71, entrance curve section 72, and measures arc section 73 and an exit curve 74, described straight-line segment 71 and the junction of entrance curve section 72 form one and shunt most advanced and sophisticated 75, and straight-line segment 71 and measurement arc section 73 are linked together by the transition of S type by described entrance curve section 72; Measurement arc section 73 and straight-line segment 71 are linked together by the transition of S type by described exit curve 74, and described exit curve 74 and the junction of straight-line segment 71 form one and conflux most advanced and sophisticated 76;
The both sides of described air intake opening 3 are provided with chamfering, such that air intake opening 3 is round and smooth to be extended out in horn-like; The gas entered by air intake opening 3 is after most advanced and sophisticated 75 shuntings of shunting of central protuberance 7, and a part enters split channel 5, and another part enters Measurement channel 6;
Described split channel 5 is corresponding with straight-line segment 71 position of central protuberance 7, and the gas entering split channel 5 is contracted to gas outlet 4 along the straight sidewall of split channel 5 both sides gradually from upstream to downstream;
Described Measurement channel 6 comprise be communicated with successively horizontal flow channel 61, longitudinal main channel 62 and horizontal flow pass 63;
Described horizontal flow channel 61 corresponds to entrance curve section 72 position of central protuberance 7, and described horizontal flow pass 63 corresponds to exit curve 74 position of central protuberance 7;
The measurement arc section 73 of projection 7 centered by a sidewall of described longitudinal main channel 62, another sidewall is provided with a curved surface 64 consistent, towards the opposite with described measurement arc section radian, the centre position of described curved surface 64 is provided with a breach, and described breach is for inserting sensor chip 8;
The bottom surface of described longitudinal main channel 62 is provided with a rising step 65, between described rising step 65 and bottom surface, passes through sloped transition; Position corresponding with rising step 65 on described top cover 2 is provided with a decline step 66 identical with rising step 65 structure; Gap is left between the bottom of described breach and rising step 65;
The structure of described Measurement channel 6 makes, after top cover 2 fastens, to enter the gas of Measurement channel 6 first along the curvilinear sidewall of horizontal flow channel 61 both sides, and what maintenance cross-sectional area was constant flow to longitudinal main channel 62; Afterwards in longitudinal main channel 62 owing to measuring the restriction of arc section 73, curved surface 64, rising step 65 and decline step 66, make the gas that enters at left and right directions and above-below direction from large to small all first, that changes from small to big flow to horizontal flow pass 63 again, and along the curvilinear sidewall of horizontal flow pass 63 both sides, keep cross-sectional area constant flow to gas outlet 4; Outflow is converged in gas outlet 4 through split channel 5 and Measurement channel 6.
Preferably, the bottom surface of described Measurement channel 6 offers a through hole 9, on described top cover 2, corresponding position also offers measure-alike, the central axes of a through hole 9, two through holes 9, can prevent described gas flow structure from sending howling when air-flow flows through like this.
It is apparent to one skilled in the art that the present invention can change into various ways, and such change is not thought and departed from the scope of the present invention.All like this to the apparent amendment of the technician in described field, by be included in this claim scope within.
Claims (3)
1. a gas flow structure for air flowmeter, comprises matrix (1) and top cover (2), and described top cover (2) is fastened on the described gas flow structure of the upper formation of matrix (1);
It is characterized in that: described matrix (1) is provided with the relative air intake opening in position (3) and gas outlet (4), and the split channel (5) to be all communicated with air intake opening (3) and gas outlet (4) and Measurement channel (6), described split channel (5) and Measurement channel (6) are separated by a central protuberance (7);
The circumference of described central protuberance (7) comprises a straight-line segment (71), an entrance curve section (72), measures arc section (73) and an exit curve (74), described straight-line segment (71) and the junction of entrance curve section (72) form one and shunt most advanced and sophisticated (75), and straight-line segment (71) and measurement arc section (73) are linked together by the transition of S type by described entrance curve section (72); Described exit curve (74) will be measured arc section (73) and straight-line segment (71) by the transition of S type and link together, and described exit curve (74) and the junction of straight-line segment (71) form one and to conflux tip (76);
The both sides of described air intake opening (3) are provided with chamfering, such that air intake opening (3) is round and smooth to be extended out in horn-like; The gas entered by air intake opening (3) is after the shunting of the shunting tip (75) of central protuberance (7), and a part enters split channel (5), and another part enters Measurement channel (6); Described split channel (5) is corresponding with straight-line segment (71) position of central protuberance (7), and the gas entering split channel (5) is contracted to gas outlet (4) along the straight sidewall of split channel (5) both sides gradually from upstream to downstream.
2. the gas flow structure of air flowmeter according to claim 1, it is characterized in that, described Measurement channel (6) comprises the horizontal flow channel (61) be communicated with successively, longitudinal main channel (62) and horizontal flow pass (63);
Described horizontal flow channel (61) is corresponding to entrance curve section (72) position of central protuberance (7), and described horizontal flow pass (63) is corresponding to exit curve (74) position of central protuberance (7);
The measurement arc section (73) of projection (7) centered by a sidewall of described longitudinal main channel (62), another sidewall is provided with a curved surface (64) consistent, towards the opposite with described measurement arc section (73) radian, the centre position of described curved surface (64) is provided with a breach, and described breach is for inserting sensor chip (8);
The bottom surface of described longitudinal main channel (62) is provided with a rising step (65), between described rising step (65) and bottom surface, passes through sloped transition; The upper position corresponding with rising step (65) of described top cover (2) is provided with a decline step (66) identical with rising step (65) structure; Gap is left between the bottom of described breach and rising step (65);
The structure of described Measurement channel (6) makes after top cover (2) fastens, enter the gas of Measurement channel (6) first along the curvilinear sidewall of horizontal flow channel (61) both sides, what maintenance cross-sectional area was constant flow to longitudinal main channel (62); Afterwards in longitudinal main channel (62) owing to measuring the restriction of arc section (73), curved surface (64), rising step (65) and decline step (66), make the gas that enters at left and right directions and above-below direction from large to small all first, that changes from small to big flow to horizontal flow pass (63) again, and along the curvilinear sidewall of horizontal flow pass (63) both sides, keep cross-sectional area constant flow to gas outlet (4); Outflow is converged in gas outlet (4) through split channel (5) and Measurement channel (6).
3. the gas flow structure of air flowmeter according to claim 1, it is characterized in that, the bottom surface of described Measurement channel (6) offers a through hole (9), the upper corresponding position of described top cover (2) also offers a through hole (9), measure-alike, the central axes of two through holes (9).
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510385785.3A CN104964721B (en) | 2015-06-30 | 2015-06-30 | The gas flow structure of mass air flow sensor |
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| CN201510385785.3A CN104964721B (en) | 2015-06-30 | 2015-06-30 | The gas flow structure of mass air flow sensor |
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| CN104964721A true CN104964721A (en) | 2015-10-07 |
| CN104964721B CN104964721B (en) | 2017-12-05 |
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| CN201510385785.3A Active CN104964721B (en) | 2015-06-30 | 2015-06-30 | The gas flow structure of mass air flow sensor |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108318081A (en) * | 2018-03-30 | 2018-07-24 | 惠州华阳通用电子有限公司 | A kind of device of detection automobile interior exterior air quality |
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| CN108318081B (en) * | 2018-03-30 | 2024-04-09 | 惠州华阳通用电子有限公司 | Device for detecting air quality inside and outside automobile |
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| CN104964721B (en) | 2017-12-05 |
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Effective date of registration: 20200312 Address after: 325204 No.1, Jixiang Road, Tangxia Town, Ruian City, Wenzhou City, Zhejiang Province Patentee after: Zhejiang Baian Technology Co., Ltd Address before: Auspicious Road North Industrial Park, 325204 Zhejiang city of Wenzhou province Ruian City Tangxia No. 1 Patentee before: Cai Fengyong |