JP3471609B2 - Gas rate sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas rate sensor for detecting an angular velocity generated on a traveling body from a deflected state of a jetted gas flow. The present invention relates to a gas rate sensor adapted to be introduced into a pipe.

[0002]

2. Description of the Related Art Conventionally, a gas rate sensor has been known as a device for detecting an angular velocity generated when a vehicle is running, and is used for obtaining a change in the traveling direction of a vehicle in a car navigation system. In this gas rate sensor, a gas flow pipe having a gas flow passage formed inside is fixed to a vehicle body, a constant amount of gas flow is constantly ejected into the gas flow pipe, and the gas flow when the vehicle changes its traveling direction. The angular velocity generated in the vehicle is detected from the deflection state (that is, the direction and magnitude of the deflection).

Such a gas rate sensor is generally constructed so that the gas discharged from a piezoelectric pump for discharging the gas is introduced into the gas flow pipe to form a gas flow in the gas flow path. Further, a receiving member is joined to the gas introduction port of the gas flow pipe, and the gas discharging port and the receiving member of the pump are connected by a joint tube having one end attached to each of them.

[0004]

Since the housing of the gas flow tube is formed by etching based on the silicon substrate, the gas inlet should be formed in a circular shape like the gas outlet and the receiving member. Is difficult and we have no choice but to make it rectangular. Therefore, the flow path of the gas discharged from the pump may suddenly change from a circular shape to a rectangular shape at the stage of flowing into the gas flow tube from the receiving member, causing turbulence, which deteriorates the angular velocity detection accuracy. There was a problem.

The present invention has been made in view of such a problem, and guides the gas discharged from the pump into the gas flow pipe in a stable state to form a gas flow without turbulence to detect the angular velocity. It is an object of the present invention to provide a gas rate sensor that can increase

[0006]

In order to achieve the above object, in the present invention, a pump for discharging gas from a gas discharge port (for example, the piezoelectric pump 7 in the embodiment).
And a housing (for example, one formed from a silicon substrate)
A gas flow channel is formed inside the gas flow channel, and a gas discharged from a pump is introduced from a rectangular gas inlet formed in the housing to form a gas flow in the gas flow channel (for example, a sensor in the embodiment. In a gas rate sensor including a tip 5) and a cylindrical receiving member (for example, the receiving port 59 in the embodiment) that connects the gas discharging port and the gas introducing port, the gas discharging port and the gas introducing port are The center axes of the two members are arranged to face each other, and the inner diameter of the receiving member is set smaller than the length of the short side of the gas introduction port.

With such a structure, the gas discharged from the gas discharge port is guided into the gas flow pipe in a stable state without being disturbed, and a gas flow having no disturbance is formed in the gas flow passage to obtain an angular velocity The detection accuracy can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a gas rate sensor 1 according to the present invention. The gas rate sensor 1 includes a base 2, a board stay 3 mounted on the base 2, an electronic circuit board 6 to which an electronic circuit body 4 and a sensor chip 5 are mounted and fixedly held by the board stay 3. The piezoelectric stay 7 for supplying gas into the sensor chip 5 and the electronic device such as the electric circuit board 6 are protected by the board stay 3 so as to be fixed and held above the sensor chip 5. It is composed of a resinous pump stay 8 to be mounted, a cap 9 opened downward so as to cover these components from above, and the like. The assembled state of these components is shown in FIG. 2 (however, the cap 9 is omitted, and the lid 8 of the pump stay 8 is shown).
6 is open). As will be described later, the gas rate sensor 1 is attached to the vehicle C so that the direction of the FWD shown in FIGS. 1 and 2 is forward, so that the direction of FWD will be described below as the front.

As shown in FIG. 1, a plurality of terminals 21 are provided on the left and right upper surfaces of the base 2, and lead portions 22 connected to these terminals 21 are formed so as to extend downward from the lower surface of the base 2. ing. In addition, power supply and signal input / output with the outside are performed via the lead portion 22.

The board stay 3 has a horizontal portion 31 mounted on the upper surface of the base 2 by spot welding, and a vertical portion 32 extending vertically upward from both left and right sides of the horizontal portion 31. Further, an intermediate portion above the vertical portion 32 is horizontally bent inward to form a bent portion 33. Further, a circular hole 34 is formed in the front portion of each of the left and right vertical portions 32, and a notch 35 that is horizontally provided from the rear is provided in the rear portion.

On the lower surface of the electronic circuit board 6, the electronic circuit body 4 is provided.
The lead portion 41 extending from the electronic circuit body 4 is soldered in accordance with the wiring pattern printed on the lower surface of the electronic circuit board 6. A plurality of resistors 4a and the like are attached to the front and rear of the electronic circuit body 4. The sensor chip 5 is attached to the center of the upper surface of the electronic circuit board 6 so as to extend in the front-rear direction. After the electronic circuit main body 4 and the sensor chip 5 are mounted on the upper and lower surfaces of the electronic circuit board 6 in this manner, the left and right side portions are the board stays 3
It is attached by being adhered to the bent portion 33.

Bonding pads 61, which are electrically connected to the wiring pattern on the lower surface of the electronic circuit board 6, are formed in line on the upper surfaces of both sides of the electronic circuit board 6, and the electronic circuit board 6 is attached to the board stay 3. Then, it is connected to the corresponding terminal 21 provided on the base 2 by the fine electric wire 62 made of aluminum. Here, when the fine electric wires 62 are bonded, a vertical load is applied to the substrate 3, but as described above, since the lower surfaces of the left and right bonding pad 61 rows are surface-supported by the bent portions 33, this is used as a spacer or the like. The out-of-plane bending does not occur in the substrate 3 unlike the case of intermittent point support. For this reason, positional displacement during bonding is prevented, and accurate bonding can be performed. A female connector C1 connected to the wiring pattern on the lower surface is attached to the front of the upper surface of the substrate 3. The female connector C1 is connected to a male connector C2 on the piezoelectric pump 7 side described later.

An exploded view of the sensor chip 5 is shown in FIG. Lower base 51a and upper base 51b made of silicon
A gas reservoir 52 and a gas flow channel 53 formed by etching are provided inside a base body 51 formed by combining the above, and by a nozzle 55 provided on a wall 54 partitioning the gas reservoir 52 and the gas flow channel. It is in communication. Further, the gas reservoir 52 on the side of the upper base body 51b is communicated with the outside by a gas introduction port 56 formed in a square shape by etching (it is difficult to form a circle because of etching), and the gas flow paths of the upper and lower base bodies 51a, 51b. 53
A gas exhaust port 57 is formed to communicate with the outside.

The gas channel 53 of the lower substrate 51a is provided with a bridge 58 formed of a silicon nitride film so as to bridge between the side walls of the channel, and the platinum 58 is further formed on the upper surface of the bridge 58. A pair of heat-sensitive resistance elements R1 and R2 having a component of is formed. The bridge 58 and the heat-sensitive resistance elements R1 and R2 are both formed by depositing a silicon nitride film and a platinum film on the upper surface of the lower base body 51a and then etching.

The structure of the piezoelectric pump 7 will be described with reference to FIG. The piezoelectric pump 7 includes a casing 71 in which a lower casing 71a and an upper casing 71b are integrally combined, and a metal disc 72 whose outer circumference is sandwiched between upper and lower casings 71a and 71b.
A diaphragm 72 having a piezoelectric vibrator 72b attached to one surface of a. Diaphragm 7
In No. 2, it is possible to perform flexural vibration in the out-of-plane direction by inputting an alternating signal to both piezoelectric vibrators 72b and alternately expanding and contracting them. Further, an air chamber 73 formed in the housing 71 is divided by a diaphragm 72 into a lower first air chamber 73a and an upper second air chamber 73b, and the metal disk 72a has a first air chamber. 73a and the second air chamber 7
A circular orifice 74 communicating with 3b is provided.

A forward projecting portion 75 projecting downward is formed in front of the lower part of the lower casing 71a (leftward in FIG. 4), and the inside thereof constitutes a part of the first air chamber 73a. . In addition, a gas inlet port 76 that communicates the first air chamber 73a with the outside is provided on the front side wall of the front protrusion 75. Further, a rear protruding portion 77 that protrudes downward is formed behind the lower portion of the lower casing 71a.
7 has a first air chamber 73 at a position facing the orifice 74.
A circular gas discharge port 78 that communicates a with the outside is formed.

One lead wire L connected to the piezoelectric vibrator 72b on the side of the first air chamber 73a is drawn out through a lead hole 79 provided adjacent to the gas suction port 76. The lead wire L is soldered to the piezoelectric vibrator 72b so as to be parallel to the diaphragm 72,
This prevents the tension of the lead wire L from inhibiting the vibration of the diaphragm 72. The tip of the lead wire L pulled out to the outside is attached to the male connector C2 and is connected to the above-mentioned female connector C1.

Here, when the diaphragm 72 bends downward, the volume of the second air chamber 73b expands to a pressure lower than that of the first air chamber 73a side, and the gas sucked from the suction port 76 becomes the first air chamber. 73a through the orifice 74 to the second
It flows into the air chamber 73b (suction operation). On the other hand, when the diaphragm 72 bends upward, the volume of the second air chamber 73b contracts and becomes higher than that of the first air chamber 73a side, and the gas in the second air chamber 73b becomes the orifice 74 and the first air chamber 7b.
It flows out from the gas discharge port 78 through 3a (discharge operation). In this way, the diaphragm 72 bends in the vertical direction to perform gas pump operation.

As shown in FIG. 5 (enlarged view of region D in FIG. 4), the gas discharge port 78 is set so that its center Q1 is concentric with the center Q2 of the orifice 74 (that is, the gas discharge port 78 and (Orifice 74 is disposed so as to face the center axis substantially the same), and its diameter φA
1 is set to be larger than the diameter φA2 of the orifice 74. Further, the shortest distance M between the orifice 74 and the gas discharge port 78 is set to be substantially the same as the diameter φA1 of the gas discharge port 78. The gas that has passed through the orifice 74 is discharged from the gas discharge port 78 while spreading in a conical shape.
It is possible to minimize the amount of gas that is lost by being bounced off by the inner surface 78a of the lower housing 71a after passing through the No. 4 position.

The gas discharge port 78 is connected to the gas introduction port 5 of the sensor chip 5 through the receiving port 59 and the joint tube 60.
6 is connected. As shown in FIG. 6 and FIG. 7, the ceramic receiving port 59 is a disc-shaped base portion 59a that is adhesively attached to the gas introducing port 56 and the cylindrical portion 5 formed above it.
9b, and a through hole is formed in the vertical direction. Further, the joint tube 60 made of silicon rubber is provided with through holes in the up-down direction, so that the upper port 60a and the lower port 60 are
The lower port 60b is attached to the cylindrical portion of the receiving port 59, and the upper port 60a is attached to the gas discharge port 78.
In addition, the gas discharge port 7 by this joint tube 60
The connection between the sensor chip 5 and the sensor chip 5 is performed at a stage where the pump stay 8 on which the piezoelectric pump 7 described later is mounted is attached to the base stay 3.

As shown in FIG. 8, the center Q3 of the gas inlet 56, the center Q4 of the receiving port 59, and the gas outlet 78 described above.
Are set to be substantially concentric with each other (that is, the gas introduction port 56 and the receiving port 59 are opposed to each other with their central axes substantially aligned with each other). The length B of the short side is larger than the inner diameter φA3 of the receiving port 59 described above (see FIG. 8). Therefore, the gas discharged from the gas discharge port 78 of the piezoelectric pump 7 is introduced into the sensor chip 5 in a stable state without causing turbulence.

The structure of the pump stay 8 will be described with reference to FIG. The pump stay 8 has a structure in which the piezoelectric pump 7 can be easily attached to the electronic circuit board 6 and the sensor chip 5 attached to the board stay 3. The pump stay 8 protects the upper side of the electronic device such as the electronic circuit board 6 and has a horizontal base 81 for mounting the above-described piezoelectric pump 7, and two horizontal bases 81 extending downward from the base 81. A front leg 82 and two rear legs 83, a front holding portion 84 formed in an arc shape extending leftward and rightward in front of an upper surface of the base 81, and a rearward extension extending leftward and rightward in an upper surface of the base 81. It has a rear holding portion 85 and a lid 86 which is swingable around a hinge 85a formed on the upper edge of the rear holding portion 85. In addition, these base parts 8
1, the front leg 82, the rear leg 83, the front holding portion 84, the rear holding portion 85, and the lid 86 are integrally formed.

The base 81 is provided with a hole 81a into which a front protrusion 75 and a rear protrusion 78 are formed, which are formed in the lower portion of the piezoelectric pump 7, and a hinge 85a of a lid 86. A front tongue portion 86a and side tongue portions 86b and 86c are formed to project inward and outward in the outer peripheral portion except for.
Further, a groove-shaped key portion 84a that fits with the front tongue portion 86a is formed on the upper portion of the front holding portion 84.

FIG. 10 (view from the view A in FIG. 9)
As shown in, a cylindrical boss 87 is formed at the lower part of each front leg 82 so as to project inward in the left and right direction.
As shown in the figure, the lower portion of the tip of the boss 87 is cut in an inclined shape to form an inclined surface 87a. Further, as shown in FIG. 11 (a view seen from the arrow B in FIG. 9),
At the lower part of each of the two rear legs 83, a claw 88 is formed so as to project inward in the left and right directions. Furthermore, FIGS.
As shown in, the front leg 82 and the rear leg 83 are each formed with an interference prevention plate 89 that extends outward in the left and right directions and expands downward.

Next, the procedure for attaching the piezoelectric pump 7 to the pump stay 8 will be described. For this, first, with the lid 86 of the pump stay 8 open, the front protrusion 75 and the rear protrusion 77 formed below the piezoelectric pump 7 are fitted into the holes 81a and 81b of the pump stay 8, respectively. At this time, the lead wire L extending from the piezoelectric pump 7 is pulled out from below the hole 81a. Next, the lid 86 is hinged 8.
The front tongue portion 86a is swung around 5a and the front holding portion 8
No. 4 key portion 84a and side tongue portion 86
b and 86c are fitted between the left and right ends of the front holding portion 84 and the rear holding portion 85. As a result, the piezoelectric pump 7 is fixedly held on the pump stay 8.

The pump stay 8 to which the piezoelectric type pump 7 is thus attached is attached to the substrate stay 3.
This mounting process will be described with reference to FIG. 12 (in FIG. 12, the right side of the figure corresponds to the front). First, the pump stay 8 to which the piezoelectric pump 7 is attached is tilted forward, and the inclined surface 87a formed on the boss 87 is attached to the substrate stay 3.
The boss 87 is fitted into the circular hole 34 while being pressed toward the rear circular hole 34 which is brought into contact with the front of the vertical portion 32, and the left and right front legs 82 are slightly narrowed inward. As a result, the boss 87 and the circular hole 34 are pivotally connected to each other, and the pump stay 8 can be oscillated and swung about the pivot shaft. Front legs 8 like this
After the 2 and the circular hole 34 are pivotally connected, the pump stay 8 is swung in the direction of lowering the rear leg 83, and the pawl 88 formed on the rear leg 83 is provided on the vertical portion 32 of the substrate stay 3. The cutout 35 is engaged and locked. It should be noted that the claw 88 is also provided with an inclined surface 88a similarly to the boss 87 to facilitate the engagement with the notch 35.

Here, the lower end portions of the two front legs 82 are attached to the board stay 3 on the rear side (that is, the inner side of the swing) of the front and rear portions sandwiching the swing shaft. In the state, there is provided a downwardly protruding portion that is pressed against and abuts on the upper surface of the horizontal portion 31 of the substrate stay 3. For example, as shown in FIG. 12, the distance S1 from the center P1 of the boss 87 to the rear lower end P2 is longer than the distance S2 from the center P3 of the circular hole 34 of the vertical portion 32 to the upper surface P4 of the horizontal portion 31. To form. With such a configuration, a moment about the swing axis in the direction in which the rear leg 83 is pulled up acts on the pump stay 8 in the state where the pump stay 8 is attached to the substrate stay 3. Therefore, the locking force between the claw 88 and the notch 35 is increased, and the pump stay 8 is firmly fixed to the substrate stay 3. As shown in FIG. 12, it is preferable to form R on the front side of the lower end portion of the front leg 82 so that the lower end portion on the rear side and the horizontal portion 31 are smoothly brought into contact with each other. Need not be provided.

In this way, the pump stay 8 is replaced by the substrate stay 3
The piezoelectric pump 7 is mounted on the base 2
Although it can be mounted on the electronic circuit board, the electronic device such as the electronic circuit board 6 is covered with the pump stay 8 at the same time to prevent contact with other parts. Further, in this state, the interference prevention plate 89 is located outside of the fine electric wire 62, so that the fine electric wire 62 can be reliably protected.

The pump stay 8 is replaced by the substrate stay 3
The piezoelectric pump 7 and the sensor chip 5 are connected to each other in the process of being attached to. Therefore, before attaching the pump stay 8 to the substrate stay 3, the receiving port 59 is adhesively attached to the gas introduction port 56 of the sensor chip 5, and the upper port 60a of the joint tube 60 is attached to the discharge port 78 of the piezoelectric pump 7. Is attached. Therefore, the pump stay 8
The lower opening 60b of the joint tube 60 is fitted into the cylindrical portion 59b of the receiving opening 59 at the same time when the mounting opening is attached to the board stay 3, and the receiving opening 59 and the joint tube 60 are connected. As a result, the discharge port 78 of the piezoelectric pump 7 and the gas introduction port 56 of the sensor chip 5 are connected. With such a structure of the pump stay 8, the base 2 of the piezoelectric pump 7 is
And the piezoelectric pump 7 and the sensor chip 5 are easily connected to each other.

After the above procedure is completed, the piezoelectric pump 7
The cap 9 is covered from above, but at this time, the lower edge portion 91 (see FIG. 1) of the cap 9 is guided by the interference prevention plates 89 provided on the front leg 82 and the rear leg 83 of the pump stay 8 and the base 2 It is fitted in the groove 23. In this way, the interference prevention plate 89 prevents interference between the lower edge portion 91 and the fine electric wire 62 when the cap 9 is put on, and prevents the fine electric wire 62 from being damaged.

Next, the operation of the gas rate sensor 1 will be described. The piezoelectric pump 7 to which the drive signal is input performs pump operation of gas, and supplies gas from the gas discharge port 78 to the gas introduction port 56 of the sensor chip 5 through the joint tube 60 and the receiving port 59. The gas flowing into the gas inlet 56 is temporarily stored in the upstream passage 52a and then accelerated by the nozzle 55 to become a high-speed gas flow, which is the gas flow path 53.
Erupted inside. Then, the thermal resistance elements R1 and R2 provided in the gas flow path 53 are cooled and discharged from the gas exhaust port 57.

As described above, the heat-sensitive resistance elements R1 and R2 are cooled by the jetted gas flow, but unless the gas rate sensor 1 itself has an angular velocity, the direction of the gas flow is the sensor chip 5. Since they coincide with the direction of the central axis AX1 (see FIG. 6), both the thermal resistance elements R1 and R2 are cooled equally. At this time, the resistance values r1 and r2 of both heat-sensitive resistance elements R1 and R2 are equal. On the other hand, when the gas rate sensor 1 itself has an angular velocity, the direction of the gas flow ejected due to inertia shifts from the direction of the central axis AX1 of the sensor chip 5 to the left and right, and the thermosensitive resistance elements R1 and R2 are equal to each other. There is a difference between the two resistance values r1 and r2 without being sufficiently cooled.

The thermal resistance elements R1 and R2 are resistors R3 and R4.
And a bridge circuit as shown in FIG. 13, and the resistance values r1, r2, r of the resistors R1, R2, R3, R4.
3 and r4 are set equal to each other. Here, when one of the thermal resistance elements is cooled by the deflection of the gas flow, the resistance values r1 and r2 change corresponding to the deflection of the gas flow, and a potential difference between AB is generated. The angular velocity can be detected by detecting the potential difference between AB.

Next, the case where the gas rate sensor 1 is mounted on a vehicle and used will be described. As shown in FIGS. 14 and 15, when the gas rate sensor 1 is attached to the vehicle C, a sensor case 11 is used, and a power supply circuit board 13 is inserted therein in addition to the gas rate sensor 1. The power supply circuit board 13 has an adapting function of stabilizing the power supplied from the vehicle C to the sensor 1 to an appropriate value.
And then the circuit board 13 is fixed to the case 11 with the screw 14. In addition, the terminal 1 in the coupler portion 15 formed integrally with the case 11
5a is also conductively connected to the power supply circuit board 13 at this time. Note that the lid 1 is inserted after the sensor 1 and the circuit board 13 are inserted.
6 is attached by screwing or bending fitting.

The sensor case 11 is provided with a plurality of bolt holes 12 each having a flat surface portion 12a which is precisely projected. The bolts are passed through the bolt holes 12 to be screwed into the vehicle C so that the sensor 1 can be accurately mounted on the vehicle. You can At this time, the jet direction of the gas flow, that is, the central axis AX1 of the sensor chip 5 is provided so as to be parallel to the front-rear axis AX2 of the vehicle C. In this embodiment, the gas flow is ejected in the front direction of the vehicle C, but the gas flow is ejected in the vehicle C direction.
It may be provided so as to face the rear of the.

As described above, by mounting the gas rate sensor 1 on the vehicle C and detecting the potential difference between AB of the bridge circuit, the angular velocity due to the change in the traveling direction of the vehicle C can be detected. Especially in 1,
As described above, the gas discharge port 78 and the gas introduction port 56 are arranged to face each other with their central axes substantially aligned, and
Since the inner diameter of the receiving port 59 is set smaller than the length of the short side of the gas introducing port 56, the gas discharged from the gas discharging port 78 is guided into the sensor chip 7 in a stable state without being disturbed. Thereby, the gas channel 53 of the sensor chip 7
It is possible to form a gas flow without turbulence, and it is possible to improve the detection accuracy of the angular velocity.

[0037]

As described above, according to the gas rate sensor of the present invention, the gas discharge port of the pump and the gas introduction port of the gas flow pipe are arranged to face each other with their central axes substantially aligned with each other. In addition, since the inner diameter of the receiving member that connects the gas outlet and the gas inlet is set to be smaller than the length of the short side of the gas inlet, the gas discharged from the gas outlet is in a stable state without being disturbed. In this way, the gas flow can be guided into the gas flow tube, and the gas flow can be formed in the gas flow path without turbulence, so that the detection accuracy of the angular velocity can be improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a gas rate sensor according to the present invention.

FIG. 2 is a perspective view of the gas rate sensor.

FIG. 3 is an exploded perspective view of a sensor chip.

FIG. 4 is a side sectional view showing the structure of a piezoelectric pump.

5 is a detailed view of a region D in FIG.

FIG. 6 is a schematic side view showing attachment of a receiving port and a joint tube to the sensor chip.

FIG. 7 is a side view showing a state in which the gas discharge port of the piezoelectric pump and the gas introduction port of the sensor chip 5 are connected by a receiving port and a joint tube.

FIG. 8 is a plan view showing a relationship between a gas introduction port and a receiving port of the sensor chip.

FIG. 9 is a perspective view showing a configuration of a pump stay.

10 is a side view seen from the direction of arrow A in FIG.

FIG. 11 is a front view seen from the arrow B in FIG.

FIG. 12 is a side view showing an example of a configuration of a pivotally connecting portion between the pump stay and the substrate stay.

FIG. 13 is a simplified circuit diagram showing a configuration of a bridge circuit including two thermosensitive resistance elements.

FIG. 14 is a perspective view showing attachment of a gas rate sensor and a power supply circuit board to a sensor case.

FIG. 15 is a plan view showing how the sensor case is attached to the vehicle.

[Explanation of symbols]

1 Gas rate sensor 5 sensor chips 7 Piezoelectric pump 53 gas flow path 56 Gas inlet 59 Receptacle 60 joint tube 78 Gas outlet

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Kato 1-4-1, Chuo, Wako-shi, Saitama Honda R & D Co., Ltd. (56) Reference JP-A-7-12836 (JP, A) JP-A 5-288762 (JP, A) JP-A-5-2027 (JP, A) JP-A-4-256861 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 19/00 G01P 9/00

Claims (2)

(57) [Claims] 1. A pump that discharges gas from a gas discharge port, and a gas flow path is formed inside the housing, and the gas discharged from the pump is taken in from a rectangular gas introduction port formed in the housing. A gas rate sensor configured to have a gas flow pipe that forms a gas flow in the gas flow path, and a cylindrical receiving member that communicates the gas discharge port and the gas introduction port, wherein the gas discharge port And a gas rate characterized in that the gas introduction ports are arranged so as to face each other with their central axes substantially aligned, and the inner diameter of the receiving member is set to be smaller than the length of the short side of the gas introduction port. Sensor. 2. The gas rate sensor according to claim 1, wherein the housing of the gas flow tube is formed of a silicon substrate.