阅读说明：本技术 物理量检测装置 (Physical quantity detecting device ) 是由 五来信章 三木崇裕 上之段晓 斋藤直生 于 2020-02-07 设计创作，主要内容包括：本发明获得一种能够减少伴有异物的空气的引入量的物理量检测装置。本发明的物理量检测装置(20)的特征在于,具备配置在供被测量气体(2)流动的主通道上的壳体,壳体中配置有：第2副通道(B),其引入在主通道中流动的被测量气体(2)的一部分；电路室(135),其收容有检测被测量气体(2)的压力的压力传感器(320)；以及压力导入通道(170),其一端开设于第2副通道(B)的通道途中,另一端开设于电路室(135),能够从第2副通道(B)向电路室(135)导入被测量气体(2)的压力；压力导入通道(170)在从第2副通道(B)的侧壁面(152b)朝外侧偏移的位置配置有导入口(171)。(The invention provides a physical quantity detection device capable of reducing the introduction amount of air accompanied by foreign matters. A physical quantity detection device (20) according to the present invention is characterized by comprising a housing disposed in a main channel through which a gas (2) to be measured flows, wherein: a 2 nd sub-passage (B) which introduces a part of the gas (2) to be measured flowing in the main passage; a circuit chamber (135) which houses a pressure sensor (320) for detecting the pressure of the gas (2) to be measured; and a pressure introduction passage (170) having one end opened in the middle of the passage of the 2 nd sub-passage (B) and the other end opened in the circuit chamber (135), and capable of introducing the pressure of the gas (2) to be measured from the 2 nd sub-passage (B) into the circuit chamber (135); the pressure introduction duct (170) has an introduction port (171) disposed at a position offset to the outside from the side wall surface (152B) of the 2 nd sub-duct (B).)

1. A physical quantity detecting apparatus is characterized in that,

comprises a housing disposed in a main passage through which a gas to be measured flows,

the housing is provided with: a secondary passage that introduces a part of the measured gas flowing in the primary passage; a sensor chamber in which a pressure sensor for detecting a pressure of the measurement target gas is accommodated; and a pressure introduction passage having one end opened in the middle of the passage of the sub passage and the other end opened in the sensor chamber, and capable of introducing the pressure of the gas to be measured from the sub passage to the sensor chamber,

the pressure introduction duct has an introduction port disposed at a position offset outward from a side wall surface of the sub-duct.

2. The physical quantity detection apparatus according to claim 1,

the sub-passage has a forward passage portion extending in a predetermined axial direction toward one axial side and a return passage portion U-turned at an end of the forward passage portion and extending in the axial direction toward the other axial side,

the inlet is disposed on a side wall surface on an outer peripheral side of a turn-back portion that turns back in a semicircular arc shape from the outward path portion to the return path portion of the sub path, and is a curved portion located on the return path portion side with respect to a top portion of the turn-back portion.

3. The physical quantity detection apparatus according to claim 2,

a flow sensor for detecting a flow rate of the measurement target gas is disposed in the sub-passage,

the introduction port is provided on a downstream side of the flow sensor in a flow direction of the measurement target gas in the sub-passage.

4. The physical quantity detection apparatus according to claim 3,

the flow sensor is provided in the outward passage portion of the sub passage.

5. The physical quantity detection apparatus according to claim 1,

the plurality of introduction ports are provided at predetermined intervals in the flow direction of the measurement target gas in the sub-passage.

6. The physical quantity detection apparatus according to claim 1,

the pressure introduction passage has a labyrinth-shaped bent portion.

7. The physical quantity detection apparatus according to claim 1,

the sub-passage has a passage portion on a straight line extending in a predetermined axial direction,

a flow rate sensor for detecting a flow rate of the measurement target gas is disposed in the passage portion,

the introduction port is provided upstream of the flow sensor in the flow direction of the measurement target gas in the sub-passage.

Technical Field

The present invention relates to a physical quantity detection device that detects a physical quantity of intake air of an internal combustion engine, for example.

Background

Patent document 1 discloses a structure of an air flow rate measuring apparatus in which a bypass passage for introducing a part of air flowing through a main passage formed in a duct and a sub-bypass passage for introducing a part of air flowing through the bypass passage by branching off from the bypass passage are formed inside, and a sensor is provided in the sub-bypass passage.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2015-87254

Disclosure of Invention

Problems to be solved by the invention

According to the structure of patent document 1, when air with foreign matter is introduced from the bypass passage to the sub-bypass passage, the foreign matter may adhere to the sensor and contaminate the sensor.

The present invention has been made in view of the above problems, and an object thereof is to provide a physical quantity detection device capable of reducing the amount of air introduced with foreign matter.

Means for solving the problems

A physical quantity sensing device according to the present invention for solving the above-described problems is characterized by comprising a housing disposed in a main passage through which a gas to be measured flows, the housing having disposed therein: a secondary passage that introduces a part of the measured gas flowing in the primary passage; a sensor chamber in which a pressure sensor for detecting a pressure of the measurement target gas is accommodated; and a pressure introduction path having one end opened in the middle of the sub-path and the other end opened in the sensor chamber, and capable of introducing the pressure of the gas to be measured from the sub-path to the sensor chamber, the pressure introduction path having an introduction port arranged at a position shifted outward from a side wall surface of the sub-path.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, since the pressure introduction path has the introduction port arranged at a position shifted outward from the side wall surface of the sub path, the separation flow can be formed between the side wall surface and the introduction port. By this separation flow, the ambient environment of the introduction port can be brought into a negative pressure state, and the influence of the dynamic pressure of the fluid passing through the sub-passage can be made less likely. Therefore, for example, water contained in the gas to be measured can be prevented from flowing into the introduction port and blocking the introduction passage, and stable sensing can be performed by the pressure sensor of the sensor chamber.

Further features of the present invention will be apparent from the description and drawings of the present specification. Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.

Drawings

Fig. 1 is a system diagram showing an embodiment of a physical quantity detection device that uses the present invention in an internal combustion engine control system.

Fig. 2A is a front view of the physical quantity detection device.

Fig. 2B is a rear view of the physical quantity detection apparatus.

Fig. 2C is a view of fig. 2A in the direction of IIC.

Fig. 2D is a view of the IID of fig. 2A.

Fig. 2E is a plan view of the physical quantity detection device.

Fig. 2F is a bottom view of the physical quantity detection device.

FIG. 2G is a cross-sectional view taken along line IIG-IIG of FIG. 2A.

FIG. 2H is a cross-sectional view taken along line IIH-IIH of FIG. 2A.

Fig. 3 is a front view of the housing.

Fig. 4 is a rear view of the cover.

Fig. 5A is an enlarged view of the essential portion VA of the configuration shown in fig. 3.

Fig. 5B is a cross-sectional view taken along line VB-VB of fig. 5A.

Fig. 5C is a cross-sectional view of the VC-VC line of fig. 5A.

Fig. 5D is an enlarged view of a key portion of fig. 5A.

Fig. 5E is a diagram illustrating an operation of the inlet.

Fig. 6A is a diagram illustrating modification 1 of embodiment 1.

Fig. 6B is an enlarged view of the main portion VB of the configuration shown in fig. 6A.

FIG. 6C is a cross-sectional view of the VIC-VIC line of FIG. 6B.

Fig. 7A is a diagram illustrating modification 2 of embodiment 1.

Fig. 7B is an enlarged view of the main portion VC of the configuration shown in fig. 7A.

Fig. 7C is a cross-sectional view taken along line VIIC-VIIC of fig. 7B.

Fig. 8A is a front view of a housing of the physical quantity detection device in embodiment 2.

Fig. 8B is an enlarged view of the main portion VD of the configuration shown in fig. 8A.

Fig. 8C is a diagram illustrating an operation of the pressure introduction port.

FIG. 8D is a VIIID-VIIID line cross-sectional view of FIG. 8B.

Fig. 8E is a VIIIE-VIIIE line sectional view of fig. 8B.

Detailed Description

The embodiments described below (hereinafter referred to as examples) solve various problems that are desired to be solved by actual products, particularly various problems that are desired to be solved in order to be used as a detection device for detecting a physical amount of intake air of a vehicle, and have various effects. One of various problems to be solved by the following embodiments is the content described in the section of the problem to be solved by the invention, and one of various effects to be achieved by the following embodiments is the effect described in the section of the effect of the invention. The problems to be solved by the following examples and the effects achieved by the following examples will be described in the following description of the examples. Therefore, the problems and effects described in the following examples and solved by the examples are described in the contents other than the contents of the first problem and effect of the invention.

In the following embodiments, the same reference numerals denote the same components even when the figures are different, and the same effects are achieved. In the structure described above, reference numerals are used only in the drawings, and the description thereof may be omitted.

Fig. 1 is a system diagram showing an embodiment of a physical quantity detection device according to the present invention used in an electronic fuel injection type internal combustion engine control system 1. In accordance with the operation of the internal combustion engine 10 including the engine cylinder 11 and the engine piston 12, intake air is taken in as the measurement target gas 2 from the air cleaner 21, and is guided to the combustion chamber of the engine cylinder 11 via, for example, an intake gas serving as the main passage 22, a throttle body 23, and an intake manifold 24. The physical quantity of the gas 2 to be measured, which is the intake air introduced into the combustion chamber, is detected by the physical quantity detecting device 20 of the present invention, and fuel is supplied from the fuel injection valve 14 based on the detected physical quantity and introduced into the combustion chamber together with the gas 2 to be measured in a mixed gas state. In the present embodiment, the fuel injection valve 14 is provided at an intake port of the internal combustion engine, and the fuel injected into the intake port forms an air-fuel mixture together with the measurement target gas 2, and is introduced into the combustion chamber via the intake valve 15 to be combusted, thereby generating mechanical energy.

The fuel and air introduced into the combustion chamber are mixed with each other, and are ignited by the spark of the ignition plug 13 to be explosively combusted, thereby generating mechanical energy. The burned gas is guided from the exhaust valve 16 to the exhaust pipe, and is discharged as exhaust gas 3 from the exhaust pipe to the outside of the vehicle. The flow rate of the intake air, i.e., the gas 2 to be measured, introduced into the combustion chamber is controlled by a throttle valve 25 whose opening degree changes in accordance with the operation of an accelerator pedal. The amount of fuel supplied is controlled according to the flow rate of intake air led to the combustion chamber, and the driver controls the opening degree of the throttle valve 25 to control the flow rate of intake air led to the combustion chamber, whereby the mechanical energy generated by the internal combustion engine can be controlled.

Physical quantities such as the flow rate, temperature, humidity, and pressure of the intake air introduced from the air cleaner 21 and flowing through the main passage 22, that is, the measurement target gas 2, are detected by the physical quantity detecting device 20, and an electric signal indicating the physical quantity of the intake air is input from the physical quantity detecting device 20 to the control device 4. Further, the output of a throttle angle sensor 26 that measures the opening degree of the throttle valve 25 is input to the control device 4, and the output of the rotation angle sensor 17 is input to the control device 4 in order to measure the positions and states of the engine piston 12, the intake valve 15, and the exhaust valve 16 of the internal combustion engine, and the rotation speed of the internal combustion engine. In order to measure the state of the mixture ratio of the fuel amount and the air amount from the state of the exhaust gas 3, the output of the oxygen sensor 28 is input to the control device 4.

The control device 4 calculates the fuel injection amount and the ignition timing from the physical amount of the intake air, which is the output of the physical amount detection device 20, and the rotation speed of the internal combustion engine measured based on the output of the rotation angle sensor 17. The amount of fuel supplied from the fuel injection valve 14 and the ignition timing for ignition by the ignition plug 13 are controlled based on these calculation results. The fuel supply amount and the ignition time are also controlled in detail substantially in accordance with the temperature detected by the physical quantity detection device 20, the change state of the throttle angle, the change state of the engine speed, and the state of the air-fuel ratio measured by the oxygen sensor 28. Further, in the idle operation state of the internal combustion engine, the control device 4 controls the amount of air bypassing the throttle valve 25 by using the idle air control valve 27, and controls the rotation speed of the internal combustion engine in the idle operation state.

The fuel supply amount and the ignition time, which are main control amounts of the internal combustion engine, are calculated using the output of the physical quantity detection device 20 as main parameters. Therefore, improvement of the detection accuracy, suppression of temporal change, and improvement of reliability of the physical quantity detection device 20 are important for improvement of the control accuracy of the vehicle and securing of reliability.

In particular, in recent years, the expectations relating to fuel economy of vehicles are extremely high, and the expectations relating to exhaust gas purification are extremely high. In response to these expectations, it is extremely important to improve the detection accuracy of the physical quantity of the intake air detected by the physical quantity detecting device 20. In addition, it is also important for the physical quantity detection device 20 to maintain high reliability.

The vehicle mounted with the physical quantity detection device 20 is used in an environment where changes in temperature and humidity are large. The physical quantity detection device 20 is preferably designed to take account of changes in temperature and humidity in the environment in which it is used, and account for dust, pollutants, and the like.

The physical quantity detection device 20 is attached to an intake pipe that is affected by heat generated from the internal combustion engine. Therefore, the heat of the internal combustion engine is transmitted to the physical quantity detection device 20 via the intake pipe. Since the physical quantity sensing device 20 senses the flow rate of the gas to be measured by transferring heat to the gas to be measured, it is important to suppress the influence of heat from the outside as much as possible.

As described below, the physical quantity detection device 20 mounted on the vehicle not only solves the problems described in the section of the problem to be solved by the invention and obtains the effects described in the section of the effect of the invention, but also sufficiently considers the various problems described above and solves various problems to be solved by the product and obtains various effects. Specific problems to be solved and specific effects to be achieved by the physical quantity sensing device 20 will be described in the following description of the embodiments.

< embodiment 1 >

Fig. 2A to 2F are diagrams showing the appearance of the physical quantity detection device. In the following description, the gas to be measured flows along the central axis of the main passage.

The physical quantity measuring device 20 is used in a state of being inserted into the main channel 22 from a mounting hole provided in a channel wall of the main channel 22 and fixed to the main channel 22. The physical quantity detection device 20 includes a housing disposed in a main passage 22 through which a gas to be measured flows. The housing of the physical quantity detection device 20 has a case 100 and a lid 200 attached to the case 100.

The housing 100 is formed by injection molding a synthetic resin material, for example. The lid body 200 is made of, for example, a plate-shaped member made of a metal material or a synthetic resin material, and in the present embodiment, made of an injection-molded product of an aluminum alloy or a synthetic resin material.

The casing 100 has a flange 111 for fixing the physical quantity detection device 20 to the intake air, which is the main passage 22, a connector 112 protruding from the flange 111 to be exposed to the outside from the intake air for electrical connection with an external device, and a measurement portion 113 extending from the flange 111 to protrude toward the center of the main passage 22.

The measurement portion 113 has a thin and long shape extending straight from the flange 111, and has a wide front surface 121, a wide back surface 122, and a pair of narrow side surfaces 123 and 124. In a state where the physical quantity detecting device 20 is mounted on the main passage 22, the measuring portion 113 protrudes from the inner wall of the main passage 22 toward the passage center of the main passage 22. The front surface 121 and the back surface 122 are arranged in parallel along the central axis of the main passage 22, and of the narrow side surfaces 123 and 124 of the measurement unit 113, the side surface 123 on one side in the longitudinal direction of the measurement unit 113 is arranged relatively on the upstream side of the main passage 22, and the side surface 124 on the other side in the short direction of the measurement unit 113 is arranged relatively on the downstream side of the main passage 22. In a state where the physical quantity detection device 20 is attached to the main passage 22, the distal end portion of the measurement portion 113 is defined as the lower surface 125.

The measurement unit 113 has a sub-channel inlet 131 on the side surface 123, and a 1 st outlet 132 and a 2 nd outlet 133 on the side surface 124. The sub-passage inlet 131 and the 1 st and 2 nd outlets 132 and 133 are provided at the tip end portion of the measurement portion 113 extending from the flange 111 toward the center of the main passage 22. Thus, the gas of a portion closer to the central portion away from the inner wall surface of the main passage 22 can be introduced into the sub passage. Therefore, the physical quantity detection device 20 can measure the flow rate of the gas in a portion away from the inner wall surface of the main passage 22, and can suppress a decrease in measurement accuracy due to the influence of heat or the like.

The physical quantity detecting device 20 has a shape in which the measuring section 113 extends along the axial length from the outer wall of the main passage 22 to the center, but the width of the side surfaces 123 and 124 is narrow as shown in fig. 2B and 2D. Thus, the physical quantity detection device 20 can suppress the fluid resistance to a small value for the gas 2 to be measured.

As shown in fig. 2B, the physical quantity detecting device 20 is provided with an intake air temperature sensor 321 and a humidity sensor 322 as temperature detecting portions in the measuring portion 113. The intake air temperature sensor 321 is disposed in the middle of the passage of the temperature detection passage C, one end of which opens near the sub-passage inlet 131 of the side surface 123 and the other end of which opens on both the front surface 121 and the rear surface 122 of the measurement portion 113.

According to the physical quantity detection device 20 of the present embodiment, since the intake air temperature sensor 321 is disposed on the upstream side of the measurement unit 113, the gas 2 to be measured that flows straight from the upstream can be made to directly impinge on the intake air temperature sensor 321. Thus, the heat radiation performance of the intake air temperature sensor 321 can be improved.

The measurement unit 113 of the physical quantity detection device 20 is inserted into the main passage 22 from a mounting hole provided in the main passage 22, and the flange 111 of the physical quantity detection device 20 abuts against the main passage 22 and is fixed to the main passage 22 by screws. The flange 111 has a substantially rectangular shape in plan view having a predetermined plate thickness, and as shown in fig. 2E and 2F, fixing hole portions 141 are provided in pairs at diagonal corners. The fixing hole portion 141 has a through hole 142 penetrating the flange 111.

A fixing screw, not shown, is inserted into the through hole 142 of the fixing hole 141 and screwed into a screw hole of the main passage 22, thereby fixing the flange 111 to the main passage 22.

As shown in fig. 2E, the connector 112 has 4 external terminals 147 and correction terminals 148 provided therein. The external terminal 147 is a terminal for outputting physical quantities such as a flow rate and a temperature, which are measurement results of the physical quantity detection device 20, and a power supply terminal for supplying a direct current for the physical quantity detection device 20 to operate.

The correction terminal 148 is a terminal for measuring the physical quantity detection device 20 to be produced, obtaining correction values relating to the respective physical quantity detection devices 20, and storing the correction values in a memory inside the physical quantity detection device 20, and the correction terminal 148 is not used when correction data indicating the correction values stored in the memory is used in the subsequent measurement operation of the physical quantity detection device 20.

Therefore, in order to prevent the correction terminal 148 from becoming a disturbance in connection of the external terminal 147 with another external device, the correction terminal 148 is shaped differently from the external terminal 147. In this embodiment, the correction terminal 148 is shorter than the external terminal 147, and even if a connection terminal of an external device to be connected to the external terminal 147 is inserted into the connector 112, the connection is not hindered.

Fig. 2G is a sectional view taken along line IIG-IIG of fig. 2A, fig. 2H is a sectional view taken along line IIH-IIH of fig. 2A, fig. 3 is a front view of the housing, and fig. 4 is a rear view of the cover. In the following description, the direction in which the measurement unit 113 extends from the flange 111, that is, the longitudinal direction of the measurement unit 113, is referred to as the Z-axis, the direction in which the measurement unit 113 extends from the sub-channel inlet 131 toward the 1 st outlet 132 of the measurement unit 113, that is, the short-side direction of the measurement unit 113, is referred to as the X-axis, and the direction from the front surface 121 of the measurement unit 113 toward the back surface 122, that is, the thickness direction of the measurement unit 113, is referred to as the Y-axis.

The housing 100 is provided with a sub-passage groove 150 for forming the sub-passage 134 and a circuit chamber 135 for accommodating the circuit substrate 300. The circuit chamber 135 and the sub-channel groove 150 are recessed in the front surface of the measurement portion 113. The circuit chamber 135 is provided in a region on one side (side surface 123 side) in the X axis direction, which is a position on the upstream side in the flow direction of the gas 2 to be measured, in the main passage 22. The sub-passage groove 150 is provided across a region on the Z-axis direction tip side (lower surface 125 side) of the measurement unit 113 with respect to the circuit chamber 135 and a region on the other X-axis direction side (side surface 124 side) which is a position on the downstream side in the flow direction of the measurement target gas 2 in the main passage 22 with respect to the circuit chamber 135.

The sub-passage groove 150 forms the sub-passage 134 by being covered with the cover body 200. The sub passage groove 150 has a 1 st sub passage groove 151 and a 2 nd sub passage groove 152 branched halfway in the 1 st sub passage groove 151. The 1 st sub channel groove 151 is formed to extend in the X axis direction of the measurement portion 113 across between the sub channel inlet 131 opened to the side surface 123 on one side of the measurement portion 113 and the 1 st outlet 132 opened to the side surface 124 on the other side of the measurement portion 113. The 1 st sub-passage groove 151 forms a 1 st sub-passage a by cooperating with the lid body 200, the 1 st sub-passage a introducing the gas 2 to be measured flowing in the main passage 22 from the sub-passage inlet 131, and returning the introduced gas 2 to be measured to the main passage 22 from the 1 st outlet 132. The 1 st sub-passage a has a flow path extending from the sub-passage inlet 131 in the flow direction of the gas 2 to be measured in the main passage 22 to the 1 st outlet 132.

The 2 nd sub channel groove 152 branches at an intermediate position of the 1 st sub channel groove 151, bends toward the base end portion side (flange side) of the measurement portion 113, and extends in the Z-axis direction of the measurement portion 113. Then, the proximal end portion of the measurement portion 113 is bent toward the other side (side surface 124 side) in the X-axis direction of the measurement portion 113, is U-turned toward the distal end portion of the measurement portion 113, and extends in the Z-axis direction of the measurement portion 113 again. Further, the second outlet 132 is bent toward the other side (side surface 124 side) in the X axis direction of the measurement unit 113 in the vicinity of the first outlet 132, and is connected to a second outlet 133 opened in the side surface 124 of the measurement unit 113. The 2 nd outlet 133 is disposed facing the downstream side in the flow direction of the gas 2 to be measured in the main passage 22. The 2 nd outlet 133 has an opening area substantially equal to or slightly larger than that of the 1 st outlet 132, and is formed at a position adjacent to the longitudinal direction base end side of the measurement portion 113 with respect to the 1 st outlet 132.

The 2 nd sub channel groove 152 forms a 2 nd sub channel B by cooperating with the lid body 200, the 2 nd sub channel B passing the measured gas 2 branched from the 1 st sub channel a to be sent back to the main channel 22 from the 2 nd outlet 133. The 2 nd sub-channel B has a flow path that reciprocates in the Z-axis direction of the measurement portion 113. That is, the 2 nd sub-passage B has a forward passage portion B1 and a return passage portion B2, the forward passage portion B1 branches at the middle of the 1 st sub-passage a and extends toward the base end portion side of the measurement portion 113 (in the direction away from the 1 st sub-passage a), and the return passage portion B2 turns back and makes a U-turn at the base end portion side of the measurement portion 113 (the end portion facing away from the passage portion) and extends toward the tip end portion side of the measurement portion 113 (in the direction approaching the 1 st sub-passage a). The return passage portion B2 is connected to the 2 nd outlet 133 that opens toward the downstream side in the flow direction of the gas 2 to be measured at a position on the downstream side in the flow direction of the gas 2 to be measured in the main passage 22 than the sub-passage inlet 131.

The 2 nd sub-passage B has a flow rate sensor (flow rate detecting unit) 311 disposed midway to the passage portion B1. Since the 2 nd sub channel B is a channel formed to extend in the longitudinal direction of the measurement unit 113 and to reciprocate, the channel length can be secured longer, and the influence on the flow sensor 311 can be reduced when pulsation occurs in the main channel.

A flow sensor 311 is disposed within the chip package 310. The chip package has a structure in which the flow sensor 311 and the LSI are molded with resin. In the chip package 310, the proximal end portion of the package main body is fixed to the circuit board 300 in the circuit chamber 135, the distal end portion thereof is disposed in the 2 nd sub-channel groove 152 in a protruding manner, and the flow sensor 311 is provided at the distal end portion thereof. The flow sensor 311 is supported by the chip package 310 so as to be exposed to the outward path portion B1 of the 2 nd sub-path B. The flow rate sensor 311 is disposed to face the groove bottom surface 152a of the 2 nd sub-passage groove 152 with a predetermined gap therebetween, and measures the flow rate of the measurement target gas passing through the 2 nd sub-passage B.

The circuit board 300 has mounted thereon circuit components such as a chip package 310, a pressure sensor 320, an intake air temperature sensor 321, and a humidity sensor 322. The end portion of the circuit chamber 135 where the external terminal 147 protrudes is connected to the bonding pad 300 of the circuit board 300 via a bonding wire 331.

The casing 100 is provided with a destaticizing plate 340 for destaticizing the gas to be measured passing through the 2 nd sub-passage B. The destaticizing plate 340 is exposed in the 2 nd sub passage groove 152 so as to constitute a part of the groove bottom surface 152a of the 2 nd sub passage groove 152. In the present embodiment, the destaticizing plate 340 is provided to extend as follows: the position of the 2 nd sub-passage B toward the 1 st sub-passage a, which is the upstream side in the flow direction of the gas to be measured with respect to the chip package 310, extends from the position of the 2 nd sub-passage B1 to the 1 st sub-passage a, which is the downstream side in the flow direction of the gas to be measured with respect to the chip package 310, to the position of the 2 nd outlet 133, which is the downstream side in the flow direction of the gas to be measured with respect to the chip package 310.

The destaticizing plate 340 has a connection end 341 (see fig. 5A), is electrically connected to the ground of the circuit board 300 by a bonding wire 331, and performs destaticization of the gas to be measured passing through the 2 nd sub-channel B. Therefore, foreign matter contained in the gas to be measured can be prevented from adhering to the chip package 310 or the flow sensor 311 due to electrification.

The cover 200 is attached to the front surface 121 of the housing 100, and has a flat plate shape covering the circuit chamber 135 of the measurement portion 113 and the sub-passage groove 150. As shown in FIG. 4, the lid body 200 is provided with ribs 211 to 217 on the back surface 201. The ribs 211-217 are formed along the bonding portion with the measuring portion 113. As shown in FIG. 3, the measuring section 113 has grooves 261 to 268 formed in the front surface 121 for inserting ribs 271 to 278. The lid body 200 is bonded by an adhesive in a state where the ribs 271 to 278 are inserted into the grooves 261 to 268 of the measuring portion 113.

Next, a structure for detecting the pressure of the measurement target gas, which is one of the features of the present invention, will be described.

Fig. 5A is an enlarged view showing a main portion VA of the structure shown in fig. 3, fig. 5B is a cross-sectional view taken along line VB-VB of fig. 5A, fig. 5C is a cross-sectional view taken along line VC-VC of fig. 5A, and fig. 5D is an enlarged view of the main portion of fig. 5A.

The physical quantity detection device 20 has a pressure sensor 320 that detects the pressure of the gas to be measured.

The pressure sensor 320 is housed in the circuit chamber 135. The pressure sensors 320 are disposed in the circuit chamber 135 in a state of being mounted on the circuit board 300, and in the present embodiment, 2 pressure sensors 320 are disposed side by side. The circuit chamber 135 is connected to the 2 nd sub-passage B via the pressure introduction passage 170, and functions as a sensor chamber for detecting the pressure of the measurement target gas by the pressure sensor 320 by introducing the pressure of the measurement target gas in the 2 nd sub-passage B. The circuit chamber 135 is covered by attaching the lid member 200, and is sealed so that there is no portion communicating with the outside except for the pressure introduction passage 170.

As shown in fig. 5A, the pressure introduction passage 170 has a structure in which one end opens in the middle of the passage of the 2 nd sub-passage B and the other end opens in the circuit chamber 135, and the pressure of the gas to be measured can be introduced from the 2 nd sub-passage B to the circuit chamber 135. The pressure introduction passage 170 is recessed in the measurement portion 113 in a groove shape, and is configured by engagement with the lid body 200. The pressure introduction passage 170 includes an introduction port 171 opened at a position offset from the passage wall surface of the 2 nd sub-passage B, a slit-shaped linear portion 172 linearly extending from the introduction port 171, and a labyrinth-shaped bent portion 173 connected to the circuit chamber 135 while being bent a plurality of times following the linear portion 172.

The introduction port 171 is provided at a position downstream of the chip package 310 in the flow direction of the gas to be measured in the 2 nd sub-channel B, and in the present embodiment, is provided at a turn portion that turns from the outward channel portion B1 to the return channel portion B2 in the 2 nd sub-channel B. In the folded portion, a sidewall surface 152B on the outer peripheral side of the 2 nd sub passage groove 152 is curved in a semicircular arc shape, and the introduction port 171 is disposed at a portion of the sidewall surface 152B curved in a semicircular arc shape and is a curved portion which is a portion located on the side of the return passage portion B2 with respect to the top portion of the folded portion of the return passage portion B2. As shown in fig. 5D, the introduction port 171 is provided at a position shifted from the curved portion of the sidewall surface 152b by a predetermined distance k toward the outside of the curve. The predetermined distance k is set by obtaining in advance through experiments or simulations the distance at which the separation flow R is generated between the side wall surface 152B and the introduction port 171, the separation flow R being separated from the side wall surface 152B by the gas to be measured passing through the return path portion B2.

The introduction port 171 is provided in plurality at predetermined intervals in the flow direction of the measurement target gas in the 2 nd sub-path B, and in the present embodiment, 3 of the 1 st introduction port 1711, the 2 nd introduction port 1712, and the 3 rd introduction port 1713 are provided. The linear portion 172 of the pressure introduction path 170 includes a 1 st path portion 1721, a 2 nd path portion 1722, and a 3 rd path portion 1723 extending in parallel from the 1 st introduction port 1711, the 2 nd introduction port 1712, and the 3 rd introduction port 1713.

The 1 st introduction port 1711, the 2 nd introduction port 1712, the 3 rd introduction port 1713, the 1 st passage portion 1721, the 2 nd passage portion 1722, and the 3 rd passage portion 1723 have a shallow groove shape (slit shape) recessed on the side abutting against the measurement portion 113 of the cover body 200, and each have a groove depth h. As shown in fig. 5B and 5C, the groove depth h is formed extremely shallow as compared with the groove depth of the 2 nd sub channel groove 152. In the present embodiment, channel parts 1, 2, and 3 1721, 1722, and 1723 have dimensions and shapes with a width W of 1.0mm and a depth h of 0.1 mm.

As shown in fig. 5D, the 1 st introduction port 1711 is provided at a position recessed from the side wall surface 152b toward the outside of the curve with a step having a predetermined distance k from the side wall surface 152 b. Next, the 1 st channel portion 1721 of the 1 st introduction port 1711 is provided so as to extend in a direction in which an angle with the flow direction of the gas 2 to be measured flowing in the 2 nd sub channel B is 90 degrees or less. Therefore, the gas 2 to be measured flowing along the side wall surface 152b can be prevented from linearly and straightly flowing from the 1 st introduction port 1711 to the 1 st passage portion 1721, and from generating a strong separation flow R by the step portion between the side wall surface 152b and the 1 st introduction port 1711.

As shown in fig. 5A, the bent portion 173 of the pressure introduction passage 170 has a cavity portion 1731 and a bent portion 1732, the cavity portion 1731 is connected to the 1 st channel portion 1721, the 2 nd channel portion 1722 and the 3 rd channel portion 1723, respectively, and is substantially U-shaped, and the bent portion 1732 extends from the cavity portion 1731 to the circuit chamber 135 in an arc shape. As shown in fig. 5A, the chamber portion 1731 has an inverted U-shape so that the flow direction of the gas to be measured passing through the 1 st channel portion 1721, the 2 nd channel portion 1722, the 3 rd channel portion 1723, and the curved portion 1732 is changed by 180 degrees, and has a labyrinth structure in which the opening of the circuit chamber 135 and the introduction port 171 of the pressure introduction channel 170 are not connected to each other linearly. As shown in fig. 5B, the chamber portion 1731 has substantially the same depth as the groove bottom surface 152a of the 2 nd sub-channel groove 152, and forms a predetermined indoor space, and when water enters from the 2 nd sub-channel B, the water can be temporarily stored.

The curved portion 1732 has a groove shape recessed on the side abutting against the measuring portion 113 of the lid body 200, and the groove depth thereof is set to the same depth h as the 1 st channel portion 1721, the 2 nd channel portion 1722, and the 3 rd channel portion 1723. The bent portion 1732 has a circular arc shape extending along the outside of the turn-back portion of the 2 nd sub passage B.

Since the 1 st introduction port 1711 is provided in the pressure introduction path 170 at a position shifted from the side wall surface 152B of the 2 nd sub-path groove 152 toward the outside of the curve by the predetermined distance k, the separation flow R in which the gas 2 to be measured passing through the 2 nd sub-path B is separated from the side wall surface 152B can be generated between the side wall surface 152B and the 1 st introduction port 1711, that is, before the 1 st introduction port 1711. Therefore, a negative pressure environment due to the separation flow R can be formed in front of the 1 st introduction port 1711, the influence of the dynamic pressure of the measurement target gas on the 1 st introduction port 1711 can be reduced, and the inflow of air accompanied by foreign matters from the 2 nd sub-passage B to the 1 st introduction port 1711 can be reduced. Therefore, it is possible to prevent the intrusion of foreign matter into the pressure introduction passage 170 and the circuit chamber 135 and to realize stable measurement of pressure by ensuring ventilation.

In particular, in the present embodiment, the 1 st introduction port 1711 is disposed on the sidewall surface 152B of the 2 nd sub passage groove 152 on the outer side turning in a semicircular arc shape and is a curved portion turning back toward the return passage portion B2 side, and therefore, a stronger separated flow R can be generated. Therefore, the influence of the separation flow R can be further exhibited, and the 1 st introduction port 1711 can be made less susceptible to the influence of the dynamic pressure.

Further, according to the configuration of the pressure introduction path 170, since the introduction port 171 is provided on the downstream side of the chip package 310 in the flow direction of the gas to be measured in the 2 nd sub-path B, it is possible to prevent the static characteristics of the flow sensor 311 from being affected. Thus, the detection accuracy of the flow sensor 311 can be further improved.

The pressure introduction path 170 has a slit-shaped linear portion 172 linearly extending from the introduction port 171 and a labyrinth-shaped bent portion 183 connected to the circuit chamber 135 so as to be bent a plurality of times, and the opening of the circuit chamber 135 and the introduction port 171 of the pressure introduction path 170 are not linearly connected to each other. Therefore, the foreign matter contained in the gas to be measured is less likely to enter the pressure introduction passage 170 and pass through, and the foreign matter can be effectively prevented from entering the circuit chamber 135.

Fig. 5E is a view for explaining the operation of the inlet, and schematically shows a state in which water has entered the 2 nd sub-passage B.

For example, in the case where water enters the 2 nd sub-duct B as shown in fig. 5E, since the 1 st introduction port 1711 forms a negative pressure environment by the separated flow R in front of the 1 st introduction port 1711 and the influence of the dynamic pressure on the 1 st introduction port 1711 is reduced, the water can be prevented from entering the 1 st duct portion 1721 from the 1 st introduction port 1711, and the air flow can be always ensured. Thus, the pressure can be stably measured.

Since the separation flow R is less affected by the dynamic pressure of the measurement gas at the 2 nd inlet 1712 and the 3 rd inlet 1713 than at the 1 st inlet 1711, water may enter the 2 nd passage 1722 and the 3 rd passage 1723 from the 2 nd inlet 1712 and the 3 rd inlet 1713, respectively. However, since the bent portion 173 having the cavity portion 1731 and the bent portion 1732 is continuously provided to the 2 nd channel portion 1722 and the 3 rd channel portion 1723, water can be prevented from being infiltrated into the circuit chamber 135.

Next, a modification of embodiment 1 will be described. Fig. 6A to 6C are views illustrating modification 1 of embodiment 1, and fig. 7A to 7C are views illustrating modification 2 of embodiment 1.

The same reference numerals are used to designate the same components as those of the above-described embodiment, and detailed description thereof will be omitted.

Fig. 6A is a front view of a housing of a physical quantity sensing device according to modification 1, fig. 6B is an enlarged view of essential parts of the configuration shown in fig. 6A, and fig. 6C is a cross-sectional view of VIC-VIC lines in fig. 6B.

In the embodiment shown in fig. 5A, the case where the 1 st inlet 1711, the 2 nd inlet 1712, and the 3 rd inlet 1713, which are 3 inlets, are provided is described as an example, but the configuration is not limited to this. The number of the introduction ports may be 1 or more as long as a configuration is possible in which a negative pressure environment by the separation flow can be formed in front of the introduction port 171, the influence of the dynamic pressure of the gas to be measured on the introduction port 171 can be reduced, and the air accompanying the foreign matter can be reduced from flowing into the introduction port 171 from the 2 nd sub-passage B.

As shown in fig. 6A to 6B, modification 1 includes 2 inlets, that is, a 1 st inlet 1714 and a 2 nd inlet 1715. The 1 st introduction port 1714 and the 2 nd introduction port 1715 are disposed at positions on the bending start side and the bending end side of the bending portion so as to be spaced from each other. The 1 st introduction port 1714 and the 2 nd introduction port 1715 are disposed at positions shifted from the side wall surface 152b of the 2 nd sub passage groove 152 by a predetermined distance k toward the outside of the curve. Further, a 1 st channel portion 1724 and a 2 nd channel portion 1725, which are linear, are provided continuously to the 1 st inlet port 1714 and the 2 nd inlet port 1715, respectively.

As in the above-described embodiment, since the pressure introduction path 170 of modification 1 is provided with the 1 st introduction port 1714 at a position shifted from the side wall surface 152B of the 2 nd sub path groove 152 toward the outside of the curve by the predetermined distance k, a separation flow in which the gas to be measured passing through the 2 nd sub path B is separated from the side wall surface 152B can be generated between the side wall surface 152B and the 1 st introduction port 1714, that is, before the 1 st introduction port 1714. A negative pressure environment due to the separated flow can be formed in front of the 1 st introduction port 1714, the influence of the dynamic pressure of the gas to be measured on the 1 st introduction port 1714 can be reduced, and the inflow of air accompanied by foreign matters from the 2 nd sub passage B into the 1 st introduction port 1714 can be reduced. Therefore, it is possible to prevent the intrusion of foreign matter into the pressure introduction passage 170 and the circuit chamber 135 and to realize stable measurement of pressure by ensuring ventilation.

As shown in fig. 7A to 7B, modification 2 includes 1 introduction port 171 of the 1 st introduction port 1716. The 1 st introduction port 1716 is disposed at a position on the bend start side of the bend portion. The 1 st introduction port 1716 is disposed at a position shifted from the side wall surface 152b of the 2 nd sub passage groove 152 by a predetermined distance k toward the outside of the curve. Further, a linear 1 st channel 1726 is continuously provided to the 1 st inlet 1716.

As in the above-described embodiment, since the pressure introduction path 170 of modification 2 is provided with the 1 st introduction port 1716 at a position shifted from the side wall surface 152B of the 2 nd sub path groove 152 toward the outside of the curve by the predetermined distance k, a separation flow in which the gas to be measured passing through the 2 nd sub path B is separated from the side wall surface 152B can be generated between the side wall surface 152B and the 1 st introduction port 1716, that is, before the 1 st introduction port 1716. Therefore, a negative pressure environment due to the separated flow can be formed in front of the 1 st introduction port 1716, the influence of the dynamic pressure of the measurement target gas on the 1 st introduction port 1716 can be reduced, and the inflow of air accompanied by foreign matters from the 2 nd sub-passage B to the 1 st introduction port 1716 can be reduced. Therefore, it is possible to prevent the intrusion of foreign matter into the pressure introduction passage 170 and the circuit chamber 135 and to realize stable measurement of pressure by ensuring ventilation.

< embodiment 2 >

Next, embodiment 2 of the physical quantity detection device 20 of the present invention will be described.

Fig. 8A is a front view of a housing of the physical quantity sensing device according to embodiment 2, fig. 8B is an enlarged view showing a main portion VD of the structure shown in fig. 8A, fig. 8C is a view explaining an operation of the pressure introduction port, fig. 8D is a cross-sectional view taken along line VIIID-VIIID in fig. 8B, and fig. 8E is a cross-sectional view taken along line VIIIE-VIIIE in fig. 8B. The same reference numerals are used to designate the same components as those of embodiment 1, and detailed description thereof will be omitted.

The characteristic contents in the present embodiment are: the pressure introduction channel 180 is provided at a position on the upstream side of the 2 nd sub-channel B compared to the chip package 310 and is a straight line portion of the 2 nd sub-channel B.

As shown in fig. 8A to 8D, the pressure introduction passage 180 has a structure in which one end opens in the middle of the passage of the 2 nd sub-passage B and the other end opens in the circuit chamber 135, and the pressure of the gas to be measured can be introduced from the 2 nd sub-passage B to the circuit chamber 135. The pressure introduction passage 180 is recessed in the measurement portion 113 in a groove shape, and is configured by engagement with the lid body 200. The pressure introduction passage 180 includes an introduction port 181 opened at a position offset from the passage wall surface of the 2 nd sub-passage B, a straight portion 182 linearly extending from the introduction port 181, and a labyrinth-shaped bent portion 183 connected to the circuit chamber 135 while being bent a plurality of times following the straight portion 182.

As shown in fig. 8A, the introduction port 181 is provided at a position upstream of the chip package 310 in the flow direction of the gas to be measured in the 2 nd sub-channel B and is a straight portion of the 2 nd sub-channel B toward the channel B1. The side wall surface 152b of the 2 nd sub channel groove 152 has a straight portion linearly extending from the chip package 310 toward the 1 st sub channel groove 151 side, and the introduction port 181 is arranged in the straight portion. As shown in fig. 8B and 8C, the introduction port 181 is provided at a position shifted outward in the groove width direction of the 2 nd sub passage groove 152 by a predetermined distance k from the straight portion of the side wall surface 152B. The predetermined distance k is set by obtaining in advance through experiments or simulations the distance by which the separated flow R separated from the side wall surface 152B by the gas 2 to be measured flowing to the duct portion B1 can be generated between the side wall surface 152B and the introduction port 181.

The linear portion 182 of the pressure introduction passage 180 has a shape extending from the introduction port 181 toward the outside in the groove width direction of the 2 nd sub passage groove 152. The introduction port 181 and the linear portion 182 have a shallow groove shape (slit shape) concavely provided on the side abutting to the measurement portion 113 of the lid body 200, and have a groove depth h, respectively. As shown in fig. 8D and 8E, the groove depth h is formed extremely shallow as compared with the groove depth of the 2 nd sub channel groove 152. In the present embodiment, the linear portion 182 has a dimensional shape with a width W of 1.0mm and a depth h of 0.1 mm.

As shown in fig. 8C, the introduction port 181 is provided at a position recessed outward in the groove width direction of the 2 nd sub passage groove 152 from the side wall surface 152b with a step having a predetermined distance k from the side wall surface 152 b. Then, the straight portion 182 following the introduction port 181 is provided so as to extend in a direction substantially at 90 degrees to the flow direction of the gas 2 to be measured flowing in the 2 nd sub-passage B. Therefore, the gas 2 to be measured flowing along the side wall surface 152b can be prevented from linearly and straightly flowing from the introduction port 181 to the straight portion 182, and a strong separation flow R can be prevented from being generated by a step portion between the side wall surface 152b and the introduction port 181.

As shown in fig. 8E, the curved portion 183 of the pressure introduction passage 180 is formed between a step surface of the housing 100 formed to be deeper in a step shape from the linear portion 182 and a protruding portion of the lid body 200 facing the step surface with a predetermined gap therebetween. The bent portion 183 has a crank shape that is bent toward the back surface 122 side at the end of the linear portion 182 and shifted in the Y-axis direction, and bent toward the side surface 123 side at a predetermined depth position and shifted in the X-axis direction, and is configured such that the opening of the circuit chamber 135 and the inlet 181 of the pressure introduction passage 180 are not linearly connected.

Since the pressure introduction path 180 is provided with the introduction port 181 at a position shifted from the side wall surface 152B of the 2 nd sub-path groove 152 to the outside in the groove width direction by the predetermined distance k, the separation flow R in which the gas 2 to be measured passing through the 2 nd sub-path B is separated from the side wall surface 152B can be generated between the side wall surface 152B and the introduction port 181, that is, in front of the introduction port 181, as shown in fig. 8C. Therefore, a negative pressure environment due to the separation flow R can be formed in front of the introduction port 181, the influence of the dynamic pressure of the measurement target gas on the introduction port 181 can be reduced, and the inflow of air accompanied by foreign matters from the 2 nd sub-passage B to the introduction port 181 can be reduced. Therefore, it is possible to prevent the intrusion of foreign matter into the pressure introduction passage 180 and the circuit chamber 135 and to realize stable measurement of pressure by ensuring ventilation.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the embodiments, and various design changes may be made without departing from the spirit of the present invention described in the claims. For example, the embodiments are described in detail to explain the present invention in a manner easy to understand, and are not necessarily limited to all configurations described. Note that a part of the structure of one embodiment may be replaced with the structure of another embodiment, or the structure of one embodiment may be added to the structure of another embodiment. Further, addition, deletion, and replacement of another configuration may be performed on a part of the configuration of each embodiment.

Description of the symbols

2 … measured gas

20 … physical quantity detecting device

135 … Circuit chamber (sensor chamber)

170. 180 … pressure introduction passage

171. 181 … introducing port

172. 182 … straight line part

173. 183 … inflection part

310 … chip package

311 … flow sensor

320 … pressure sensor

B … sub-channel 2

B1 … go to channel part

B2 … return to the channel part.