Flow velocity measuring device

Abstract

Flow velocity measuring device, which is inserted into a through-hole (31) arranged in a pipeline (30) and measures a flow velocity of a fluid to be measured, which flows through a main passage (32) in the pipeline (30), the flow velocity measuring device with: a connector (9) having a connection port (10) that transmits and receives a signal to and from an external device; a flow velocity sensing element (2) which is arranged in a bypass passage (33) in which a portion of the fluid to be measured, which passes through the main passage (32), is received; a circuit board (3) having a bond wire pad (11) arranged on a first surface (3a) and electrically connected to the connection terminal (10) and the flow velocity sensing element (2) via a bond wire; a circuit board mounting section (8) which supports and accommodates the circuit board (3); an environmental sensor (13) mounted on the second surface (3b) of the circuit board (3) opposite the first surface (3a) and measuring the temperature, humidity and / or pressure of the fluid to be measured; and a measuring chamber (14) which is arranged in the circuit board mounting section (8), wherein the environmental sensor (13) is arranged in the measuring chamber (14), and the measuring chamber (14) has a connecting opening (15) for a connection with the main passage (32).

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to a flow velocity measuring device that measures a fluid to be measured that passes through a pipeline, such as the amount of supply air for an internal combustion engine, and in particular a flow velocity measuring device that is integrated with an environmental sensor. Description of the state of the art

[0002] Environmental sensors, such as a temperature sensor, a humidity sensor, and a pressure sensor, along with control equipment, are arranged together with a flow velocity sensor that measures the amount of intake air in the engine compartment of a vehicle using an electronically controlled fuel injection system. In recent years, reductions in labor hours for vehicle component assembly and simplification of wiring harnesses have been proposed through integration between the environmental sensors and the flow velocity sensor.

[0003] For example, US 2013 / 283895 A1 describes a circuit board of a flow velocity measuring device and a separate humidity measuring device and / or a separate pressure measuring device being built in a flow velocity measuring device housing for a flow velocity measuring device-environmental sensor integration.

[0004] In JP 5 178 388 B2, a flow velocity sensing element is arranged in a first underflow path that receives part of the inflow air from a main passage, and a moisture measuring device mounted on a circuit board of a flow velocity sensing device is arranged in a second underflow path that is located in the first underflow path.

[0005] In JP 5 279 667 B2, an environmental sensor element is arranged in a measuring chamber located in an end section of a support substrate to which a flow velocity sensing element and a signal processing circuit are attached. In this example, the measuring chamber is positioned on the side opposite the signal processing circuit, opposite an underflow path where the flow velocity sensing element is located, and has a connection hole for linking to the underflow path.

[0006] However, the following problems arise with the structures described in these patent documents when integrating the flow velocity measuring device and the environmental sensor. In US 2013 / 283895 A1, a separate environmental sensor is integrated with the flow velocity measuring device, resulting in higher labor hours for assembling the environmental sensor compared to mounting the environmental sensor on the circuit board of the flow velocity measuring device.

[0007] In the JP 5 178 388 B2, the moisture measuring device is mounted on the circuit board of the flow velocity measuring device, and the circuit board is electrically connected to a terminal via wire bonds. If the moisture measuring device is soldered to the same area as a bonding wire pad on the circuit board, flux is applied to the pad, reducing the bond strength between the wire and the pad.

[0008] After soldering the humidity sensor, the circuit board must be cleaned with a chemical to remove flux deposited on the bond wire pad. However, the environmental sensor, such as the humidity sensor, can malfunction due to chemical deposits, necessitating measures such as protecting a section of the component with a mask. This increases the number of work steps.

[0009] In one method for avoiding a circuit board cleaning process to remove flux, the bond wire pad is positioned at a sufficient distance from the electronic component, such as the moisture sensor. In this case, the circuit board is enlarged, even though flux dispersion on the pad can be prevented.

[0010] In the structure described in JP 5 178 388 B2, the second underflow path can be infiltrated by dirt, water droplets, or similar substances, and the environmental sensor element can become contaminated, which can reduce the detection sensitivity and accuracy of the environmental sensor element. Furthermore, airflow in the first underflow path can be disrupted because the second underflow path is located within the first underflow path, where the flow velocity detection element is situated. This can impair the detection accuracy of the flow velocity detection element.

[0011] In the structure described in JP 5 279 667 B2, one end of the support substrate, where the sensor element is located, is exposed in the measuring chamber, thus requiring durability and reliability from the support substrate. Accordingly, a ceramic substrate must be used for the support, which complicates cost reduction. Although the environmental sensor element, the flow velocity sensing element, and the signal processing circuit are located on the same surface of the support substrate, they cannot be positioned close to each other, necessitating a large support substrate.

[0012] DE 10 2010 043 083 A1 discloses a sensor device for detecting a flow property of a fluid medium with a sensor housing in which an electronic module with a flow sensor for detecting the flow property is included, which is at least partially enclosed in an electronics compartment.

[0013] US 2008 / 0163683 A1 discloses a packaging method and system for measuring multiple measurands with bidirectional flow, consisting of sampling openings arranged in a symmetrical pattern within a flow tube, wherein the openings are arranged symmetrically with respect to the X and Y center lines of the flow tube and to the throttling point in order to minimize turbulence within the flow tube.

[0014] DE 10 2012 220 098 A1 discloses a sensor device for detecting at least one flow property of a fluid medium, in particular for detecting the air flow in the intake tract or charge air tract of an internal combustion engine, which has a sensor housing having an electronics compartment, wherein an electronics module is arranged at least partially in this electronics compartment. SUMMARY OF THE INVENTION

[0015] The present invention was carried out to address the problems described above, and one of its objectives is to provide a low-cost flow velocity measuring device that is integrated with an environmental sensor in the interest of reliability, productivity, and size reduction.

[0016] The present invention is defined in the appended claim 1. Preferred embodiments are specified in more detail in the dependent claims.

[0017] In accordance with one aspect of the present invention, a flow velocity measuring device is provided which is inserted into a through-hole arranged in a pipeline and measures a flow velocity of a fluid to be measured which has a main passage in the pipeline, wherein the flow velocity measuring device comprises a connector having a connection port which transmits and receives a signal to and from an external device, a flow velocity sensing element arranged in a bypass passage in which a portion of the fluid to be measured is received as it passes through the main passage, a circuit board having a wire bond pad arranged on a first surface and electrically connected to the connection port and the flow velocity sensing element via a bond wire, and a circuit board receiving section which supports and receives the circuit board.an environmental sensor mounted on a second surface of the circuit board opposite the first surface and measuring the temperature, humidity and / or pressure of the fluid to be measured, and comprising a measuring chamber arranged in the circuit board receiving section, wherein the environmental sensor is located in the measuring chamber, and wherein the measuring chamber has a connecting opening for a connection to the main passage.

[0018] In accordance with the present invention, the environmental sensor is mounted on the circuit board, thus preventing any increase in the number of operations attributable to the integration of the environmental sensor and ensuring that productivity is not hindered. Since the environmental sensor is mounted on the second surface opposite the bond wire pad, the size of the circuit board can be reduced. Because the environmental sensor is located in the measuring chamber within the circuit board's mounting section, it is not directly exposed to the fluid being measured, enabling high sensing sensitivity and accuracy. Furthermore, the airflow in the bypass passage where the flow velocity sensing element is located is not obstructed, ensuring high reliability of the flow velocity measuring device without any reduction in the sensing accuracy of the flow velocity sensing element.

[0019] The aforementioned and other tasks, features, aspects and advantages of the present invention will become clear through the following detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a sectional view illustrating a flow velocity measuring device in accordance with a first embodiment of the present invention. Fig. Figure 2 is a side view in which part of the flow velocity measuring device is cut in accordance with the first embodiment of the present invention. Fig. Figure 3 is a sectional view illustrating a measuring chamber of the flow velocity measuring device in accordance with the first embodiment of the present invention. Fig. Figure 4 is a sectional view illustrating a measuring chamber of a flow velocity measuring device in accordance with a second embodiment of the present invention. Fig. Figure 5 is a sectional view illustrating the measuring chamber of the flow velocity measuring device in accordance with the second embodiment of the present invention. Fig. Figure 6 is a sectional view illustrating a measuring chamber of a flow velocity measuring device in accordance with a third embodiment of the present invention. Fig. Figure 7 is a sectional view illustrating the measuring chamber of the flow velocity measuring device in accordance with the third embodiment of the present invention. Fig. Figure 8 is a sectional view illustrating a measuring chamber of a flow velocity measuring device in accordance with a fourth embodiment of the present invention. Fig. Figure 9 is a sectional view illustrating the measuring chamber of the flow velocity measuring device in accordance with the fourth embodiment of the present invention. Fig. Figure 10 is a sectional view illustrating a measuring chamber of a flow velocity measuring device in accordance with a fifth embodiment of the present invention. Fig. Figure 11 is a sectional view illustrating the measuring chamber of the flow velocity measuring device in accordance with the fifth embodiment of the present invention. Fig. Figure 12 is a sectional view illustrating a measuring chamber of a flow velocity measuring device in accordance with a sixth embodiment of the present invention. Fig. Figure 13 is a sectional view illustrating the measuring chamber of the flow velocity measuring device in accordance with the sixth embodiment of the present invention. Fig. Figure 14 is a diagram illustrating a sensor signal processing method for a flow velocity measuring device in accordance with a seventh embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED VERSIONS First Version

[0020] A flow velocity measuring device in accordance with a first embodiment of the present invention is described below with reference to the accompanying drawings. Fig. Figure 1 is a sectional view illustrating the flow velocity measuring device in accordance with the first embodiment. Fig. Figure 2 is a side view in which part of the flow velocity measuring device is cut in accordance with the first embodiment. Fig. Figure 3 is a sectional view illustrating a measuring chamber of the flow velocity measuring device in accordance with the first embodiment. The same reference numerals are used for the corresponding parts in the drawings.

[0021] A flow velocity measuring device 1 is inserted into a through-hole arranged in a pipeline and measures the flow velocity of a fluid to be measured, which has a main passage in the pipeline. In the first embodiment, the flow velocity measuring device 1 is inserted into an insertion opening 31 formed in an inlet pipeline 30 of an internal combustion engine, as shown in Fig. Figure 1 illustrates and measures a flow velocity of supply air that has a main passage 32 in the flow pipe 30. An arrow A in Fig. Figure 2 illustrates a direction in which the supply air flows through the main passage 32.

[0022] The flow velocity measuring device 1 comprises a flow velocity sensing unit 7, a circuit board receiving section 8, and a connector 9, arranged sequentially from a tip section in the insertion direction. Within the flow velocity sensing unit 7, a flow velocity sensing element 2 is supported by a plate 4, and the plate 4 is supported by a base 5. A cover 6 is arranged to cover the base 5 and the plate 4 and is connected to the base 5 and the plate 4. The plate 4 and the cover 6 form a bypass passage 33, in which a portion of the supply air passing through the main passage 32 is received. The flow velocity sensing element 2 is arranged in the bypass passage 33.

[0023] The plate 4, the base 5 and the cover 6 form a circuit board mounting section 8. In the circuit board mounting section 8, a circuit board 3 is supported by the plate 4 with one surface (first surface 3a) of the circuit board 3 covered by the cover 6 and the other surface (second surface 3b) of the circuit board 3 covered by the base 5.

[0024] The connector 9, which has a connection port 10 that transmits and receives a signal to and from an external device (not illustrated), is formed by a portion of the base 5. The connection port 10 is integrally formed with the base 5. The flow velocity measuring device 1 is installed in the inlet pipe 30 when a portion of the base 5 is mounted to the inlet pipe 30 outside the inlet pipe by means of a screw (not illustrated) or similar device.

[0025] A bond wire pad 11 (hereinafter referred to as pad 11 for simplicity) is arranged on the first surface 3a of the circuit board 3. The circuit board 3 is electrically connected to the connection terminal 10 and the flow velocity sensing element 2 via wire bonding, in which a wire 12 is used as the bonding element.

[0026] An environmental sensor 13, which measures the temperature, humidity, and / or pressure of the fluid being measured, is soldered to the second surface 3b of the circuit board 3. In other words, the environmental sensor 13 includes a temperature measuring device provided by a temperature sensor, a humidity measuring device provided by a humidity sensor, and / or a pressure measuring device provided by a pressure sensor. The environmental sensor 13 may include measuring devices other than those described above.

[0027] Furthermore, a large number of electronic components (not illustrated), with the exception of the environmental sensor 13, are soldered to the first surface 3a and the second surface 3b of the circuit board 3. All of these electronic components, with the exception of the environmental sensor 13, can be mounted either only on the second surface 3b or only on the first surface 3a. In any case, the circuit board mounting section 8 accommodates the circuit board 3 for the electronic components, with the exception of the environmental sensor 13, so that they are not exposed to the fluid being measured.

[0028] The environmental sensor 13 is arranged in a measuring chamber 14, which is located at part of the circuit board mounting section 8. The environmental sensor 13 is the only electronic component located in the measuring chamber 14. In the first embodiment, the circuit board 3, the base 5, and the plate 4 form the measuring chamber 14. However, the measuring chamber 14 is not limited to these components. A connection between the environmental sensor 13 and the circuit board 3, which is exposed in the measuring chamber 14, is coated with a coating material.

[0029] The measuring chamber 14 has a connecting opening 15 for a connection with the main passage 32 on a surface (side surface 5a of the base 5, which is in Fig. (as illustrated in Figure 2) that is parallel to a flow direction A of the supply air passing through the main passage 32. Accordingly, the environmental sensor 13, which is arranged in the measuring chamber 14, can measure the temperature, humidity and pressure of the supply air passing through the main passage 32.

[0030] One reason why the connecting opening 15 of the measuring chamber 14 is arranged in the lateral surface 5a of the base 5, which is parallel to the flow direction A of the supply air, is explained with reference to the Fig. 2 described. Upon reaching the flow velocity measuring device 1, a portion of the supply air passing through the main passage 32 collides with a front surface 5b of the base 5 and is separated from the flow velocity measuring device 1. Accordingly, it is unlikely that any contaminants, water droplets, and the like contained in the supply air will reach the connecting opening 15, which is located in the side surface 5a perpendicular to the front surface 5b of the base 5. For this reason, it is preferred that the connecting opening 15 be located in the side surface 5a of the base 5.

[0031] Next, an assembly process is described as a method for manufacturing the flow velocity measuring device 1, which is used in a case where the electronic component, with the exception of the environmental sensor 13, is mounted on the first surface 3a of the circuit board 3 and only the environmental sensor 13 is mounted on the second surface 3b.

[0032] The electronic component, with the exception of the environmental sensor 13, is mounted by soldering to the first surface 3a, which has pad 11. The circuit board 3 is then cleaned with a chemical or similar agent to remove flux that may have been deposited on pad 11 during the soldering process. The environmental sensor 13 is then mounted by soldering to the second surface 3b of the circuit board 3.

[0033] During the assembly process, the electronic component, with the exception of the environmental sensor 13, can be mounted on either the first surface 3a or the second surface 3b. Alternatively, all electronic components, including the environmental sensor 13, can be mounted on the second surface 3b. In the latter case, no flux deposits on the pad 11, so the circuit board 3 does not need to be cleaned.

[0034] As described above, the environmental sensor 13 is mounted on the circuit board 3, as is the case with the other electronic component in accordance with the first embodiment. Accordingly, no additional process attributable to integration between the flow velocity measuring device 1 and the environmental sensor 13 is required. The environmental sensor 13 is mounted on the second surface 3b, which does not have the pad 11, so no flux is applied to the pad 11 during soldering of the environmental sensor 13. Therefore, a cleaning process of the circuit board 3 after mounting the environmental sensor 13 can be avoided.

[0035] In a case where the electronic component, with the exception of the environmental sensor 13, is soldered to the first surface 3a, which has the pad 11, the flux applied to the pad 11 can be removed by cleaning the circuit board 3 before mounting the environmental sensor 13. Accordingly, the pad 11 does not need to be positioned away from the electronic component, and the circuit board 3 can be made smaller.

[0036] Since the connecting opening 15 of the measuring chamber 14, where the environmental sensor 13 is installed, is located in the side surface 5a of the base 5, which is parallel to the flow direction A of the supply air passing through the main passage 32, it is unlikely that the measuring chamber 14 will be infiltrated by the dirt, water droplets, and similar substances contained in the supply air. Accordingly, high detection sensitivity and accuracy can be achieved with the environmental sensor 13.

[0037] Since the measuring chamber 14 is arranged in the circuit intake section 8, which is isolated from the flow velocity sensing unit 7, the environmental sensor 13 does not influence the airflow in the bypass passage 33. Consequently, a decrease in the sensing accuracy of the flow velocity sensing element 2, which is arranged in the bypass passage 33, is prevented by integration with the environmental sensor 13.

[0038] Furthermore, one end of the circuit board 3 is not exposed in the measuring chamber 14, so that a ceramic substrate for the circuit board 3 is not required and a cost-effective material, such as an epoxy glass substrate, can be selected for the circuit board 3. As described above, the miniaturized flow velocity measuring device 1, in accordance with the first embodiment, can be achieved cost-effectively by integrating the flow velocity measuring device 1 with the environmental sensor 13, thus improving reliability and productivity. Second embodiment

[0039] The Fig. 4 and Fig. Figure 5 shows sectional views of a measuring chamber of a flow velocity measuring device according to a second embodiment of the present invention. The flow velocity measuring device according to the second embodiment is similar in its overall structure to the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0040] In the flow velocity measuring device according to the second embodiment, a waterproof and moisture-permeable filter 17 is arranged at the connecting opening 15 of the measuring chamber 14 and is attached to a cap 18. The filter 17 is attached to a side surface of the cap 18 facing the main passage 32 by gluing, welding, or similar means. The cap 18 is connected to the base 5 around the connecting opening 15.

[0041] At the in Fig. In the illustrated example 4, the circuit board 3, the plate 4, the filter 17, and the cap 18 form the measuring chamber 14. However, the construction of the measuring chamber 14 is not limited to this. For example, the circuit board 3, the filter 17, and a cap 18A can form the measuring chamber 14, as shown in Fig. 5 illustrates, train. The cap 18A, which is in Fig. As illustrated in 5, the function of plate 4 is also shown in Fig. 4 and is connected to the circuit board 3.

[0042] Filter 17 is positioned at the connection opening 15, preventing the measuring chamber 14 from being infiltrated by dirt particles and water droplets contained in the supply air. Since filter 17 is permeable to moisture, a normal humidity measurement can still be performed even when the environmental sensor 13, located in measuring chamber 14, is the humidity measuring device. Therefore, filter 17 does not affect the humidity detection sensitivity or accuracy.

[0043] In accordance with the second embodiment, effects are achieved that are similar to those of the first embodiment. Additionally, in the second embodiment, the infiltration of contaminants, water droplets, and the like from the main passage 32 into the measuring chamber 14 can be prevented more reliably than in the first embodiment. Third embodiment

[0044] The Fig. 6 and Fig. Figure 7 are sectional views illustrating a measuring chamber of a flow velocity measuring device according to a third embodiment of the present invention. The flow velocity measuring device according to the third embodiment is similar in its overall structure to that of the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0045] In the second embodiment, the waterproof and moisture-permeable filter 17 is attached to the connecting opening 15 of the measuring chamber 14 by means of the cap 18. However, in the third embodiment, the filter 17 is attached directly to the connecting opening 15 on the side of the base 5, which forms the measuring chamber 14, facing the main passage 32, without using the cap.

[0046] In the example that is in Fig. As illustrated in Figure 6, the circuit board 3, the base 5, the plate 4, and the filter 17 form the measuring chamber 14. However, the construction of the measuring chamber 14 is not limited to this. For example, the circuit board 3, the base 5, and the filter 17 can form the measuring chamber 14 as shown in Figure 6. Fig. 7 illustrates, train.

[0047] In accordance with the third embodiment, effects similar to those of the second embodiment can be achieved. Furthermore, in accordance with the third embodiment, the cap 18 is not required, since the filter 17 is directly attached to the base 5, thus reducing the number of components and eliminating the need for a process to connect the cap 18 to the base 5. Fourth embodiment

[0048] The Fig. 8 and Fig. Figure 9 are sectional views illustrating a measuring chamber of a flow velocity measuring device according to a fourth embodiment of the present invention. The flow velocity measuring device according to the fourth embodiment is similar in its overall structure to the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0049] In the flow velocity measuring device according to the fourth embodiment, the waterproof and moisture-permeable filter 17 is arranged at the connection opening 15 of the measuring chamber 14 and is attached to the cap 18. The filter 17 is attached to a side surface of the cap 18 facing the measuring chamber 14 by gluing, welding, or a similar method. The cap 18 is connected to the base 5 around the connection opening 15. Due to the attachment method described above, it is unlikely that the filter 17 will come into contact with a finger or similar object during handling of the flow velocity measuring device 1, thus preventing the filter 17 from becoming detached.

[0050] In the example that is in Fig. As illustrated in Figure 8, the circuit board 3, the plate 4, the filter 17, and the cap 18 form the measuring chamber 14. However, the construction of the measuring chamber 14 is not limited to this. For example, the circuit board 3, the filter 17, and the cap 18A can form the measuring chamber 14 as shown in Figure 8. Fig. Figure 9 illustrates how to train. Cap 18A, which is in Fig. As illustrated in 9, the function of plate 4 in Fig. 8 and is connected to circuit board 3.

[0051] The filter 17 is positioned at the connection opening 15 such that the measuring chamber 14 is not infiltrated by dirt particles and water droplets contained in the supply air. Since the filter 17 is permeable to moisture, a normal humidity measurement can be performed even when the environmental sensor 13, located in the measuring chamber 14, is the humidity measuring device. Accordingly, the filter 17 does not affect the humidity detection sensitivity or accuracy.

[0052] In accordance with the fourth embodiment, effects are achieved that are similar to the effects of the first embodiment. Furthermore, in accordance with the fourth embodiment, infiltration of contaminants, water droplets, and the like from the main passage 32 into the measuring chamber 14 can be prevented more reliably than in the first embodiment. Fifth embodiment

[0053] The Fig. 10 and Fig. Figure 11 are sectional views illustrating a measuring chamber of a flow velocity measuring device according to a fifth embodiment of the present invention. The flow velocity measuring device according to the fifth embodiment is similar in its overall structure to that of the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0054] In the fourth embodiment, the waterproof and moisture-permeable filter 17 is attached to the connecting opening 15 of the measuring chamber 14 by means of the cap 18. However, in the fifth embodiment, the filter 17 is attached directly to the connecting opening 15 on an inner side of the base 5, which forms the measuring chamber 14, without the use of the cap 18. Due to the attachment method described above, it is unlikely that the filter 17 will come into contact with a finger or similar object during handling of the flow velocity measuring device 1, thus preventing the filter 17 from becoming detached.

[0055] In the example that is in Fig. As illustrated in Figure 10, the circuit board 3, the base 5, the plate 4, and the filter 17 form the measuring chamber 14. However, the construction of the measuring chamber 14 is not limited to this. For example, the circuit board 3, the base 5, and the filter 17 can form the measuring chamber 14 as shown in Figure 10. Fig. 11 illustrates, train.

[0056] In accordance with the fifth embodiment, effects similar to those of the fourth embodiment can be achieved. Furthermore, in accordance with the fifth embodiment, the cap 18 is not required, since the filter 17 is attached directly to the base 5, thus reducing the number of components and eliminating the need for a process to connect the cap 18 to the base 5. Sixth embodiment

[0057] The Fig. 12 and Fig. Figure 13 are sectional views illustrating a measuring chamber of a flow velocity measuring device according to a sixth embodiment of the present invention. The flow velocity measuring device according to the sixth embodiment is similar in its overall structure to the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0058] In a case where the connecting opening 15 is sealed by water droplets and similar substances contained in the supply air, and the measuring chamber 14 is isolated from the main passage 32, the environmental sensor 13 cannot accurately measure an environmental parameter of the supply air passing through the main passage 32. In the sixth embodiment, a projecting section 19 surrounding the connecting opening 15 is arranged on the side of the side surface 5a of the base 5 facing the main passage 32, which has the connecting opening 15, so that the water droplets and similar substances from the side surface 5a of the base 5 do not reach the connecting opening 15.

[0059] In the example that is in Fig. As illustrated in Figure 12, the projecting section 19 is integrally formed with a cap 18B, which secures the filter 17. In the example shown in Fig. As illustrated in Figure 13, the projecting section 19 has a tapered or conical section 20, the opening of which widens towards the side of the main passage and is integrally formed with a cap 18C. Since the conical section 20 is located within the projecting section 19, it is likely that water droplets adhering to the connecting opening 15 will be discharged from the connecting opening 15 along the conical section 20.

[0060] In the sixth embodiment, the projecting section 19 is integrally formed with the cap 18B and the cap 18C. However, the projecting section 19 is not limited to this. In a case where the filter 17, as in the fifth embodiment (referring to the Fig. 10 and Fig. 11) is attached directly to the base 5, the projection section can be integrally formed with the base 5.

[0061] In accordance with the sixth embodiment, the projecting section 19 surrounding the connection opening 15 is present, thus preventing the connection opening 15 from becoming sealed by water droplets and similar substances moving along the side surface 5a of the base 5. Consequently, environmental parameter measurements by the environmental sensor 13 can be performed reliably, and the reliability is further improved. Seventh embodiment

[0062] Fig. Figure 14 is a diagram illustrating sensor signal processing for a flow velocity measuring device according to a seventh embodiment of the present invention. In the seventh embodiment, an output from the environmental sensor 13 is superimposed with an output from the flow velocity measuring device 1, and the number of connection ports 10 is not increased by integration with the environmental sensor 13. The flow velocity measuring device according to the seventh embodiment is similar in its overall structure to the flow velocity measuring device according to the first embodiment, such that Fig. 1 is not used to repeat the detailed description of each section.

[0063] As in Fig.As illustrated in Figure 14, the flow velocity measuring device 1 outputs a flow velocity signal. In a case where the environmental sensor 13 includes the temperature sensor, the humidity sensor, and the pressure sensor, the flow velocity measuring device 1 outputs a temperature signal, a humidity signal, and a pressure signal. Each of the sensor signals output by the environmental sensor 13 is superimposed on the flow velocity signal in a signal processing unit of the circuit board 3 and is transmitted to a machine control unit (ECU) via the connection port 10.

[0064] Any commonly used communication method, such as an in-vehicle LAN connection, is used for communication between the flow velocity measuring device 1 and the ECU. Examples include Single Edge Nibble Transmission (SENT), Local Interconnect Network (LIN), Inter-integrated Circuit (I2C), Controller Area Network (CAN), and Peripheral Sensor Interface 5 (PSI5).

[0065] In accordance with the seventh embodiment, the flow velocity measuring device 1 and the environmental sensor 13 share the connection port 10, so that the number of connection ports 10 is not increased by integration between the environmental sensor 13 and the flow velocity measuring device 1. The embodiments of the present invention can be combined with one another within the scope of protection of the present invention, and each of the embodiments can be suitably modified or omitted.

[0066] Various modifications and changes to this invention are apparent to the person skilled in the art without departing from the core of this invention, and it is understandable that these are not limited to the illustrative embodiments presented herein.

Claims

[1] Flow velocity measuring device inserted into a through-hole (31) arranged in a pipeline (30) and measuring the flow velocity of a fluid to be measured flowing through a main passage (32) in the pipeline (30), the flow velocity measuring device comprising: a connector (9) having a connection port (10) that transmits and receives a signal to and from an external device; a flow velocity sensing element (2) which is arranged in a bypass passage (33) in which a portion of the fluid to be measured, which passes through the main passage (32), is received; a circuit board (3) having a bond wire pad (11) arranged on a first surface (3a) and electrically connected to the connection terminal (10) and the flow velocity sensing element (2) via a bond wire; a circuit board mounting section (8) which supports and accommodates the circuit board (3); an environmental sensor (13) mounted on the second surface (3b) of the circuit board (3) opposite the first surface (3a) and measuring the temperature, humidity and / or pressure of the fluid to be measured; and a measuring chamber (14) which is arranged in the circuit board mounting section (8), wherein the environmental sensor (13) is arranged in the measuring chamber (14), and the measuring chamber (14) has a connecting opening (15) for a connection with the main passage (32). [2] Flow velocity measuring device according to claim 1, wherein the measuring chamber (14) has the connecting opening (15) on a surface (5a) which is parallel to a flow direction of the fluid to be measured which passes through the main passage (32). [3] Flow velocity measuring device according to claim 1 or 2, wherein an electronic component, with the exception of the environmental sensor (13), is mounted on the first surface (3a) and / or the second surface (3b) of the circuit board (3), and the circuit board receiving section (8) receives the circuit board (3) so that the electronic component, with the exception of the environmental sensor (13), is not exposed to the fluid to be measured. [4] Flow velocity measuring device according to one of claims 1 to 3, wherein a waterproof and moisture-permeable filter (17) is arranged at the connection opening (15). [5] Flow velocity measuring device according to claim 4, wherein the filter (17) is attached to an inner side of the measuring chamber (14). [6] Flow velocity measuring device according to one of claims 1 to 5, wherein the measuring chamber (14) has a projection section (19) that surrounds the connecting opening (15) on the side of the surface (5a) which has the connecting opening (15) facing the main passage (32). [7] Flow velocity measuring device according to claim 6, in which the projection section (19) has a conical section (20) so that an opening section widens in the direction of the side of the main passage (32). [8] Flow velocity measuring device according to one of claims 1 to 7, in which the number of connection ports (10) is not increased by integration with the environmental sensor (13), since an output of the environmental sensor (13) and an output of the flow velocity measuring device are superimposed.

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