Physical quantity measuring device integrally mounted with a flow rate measuring device, and physical quantity measuring method

Abstract

Physical quantity measuring device (3) integrally mounted with a flow rate measuring device (1) for measuring a physical quantity, wherein the flow rate measuring device (1) comprises: a main body part (1a) extending inwards from an outside of a main passage of a fluid to be measured, wherein the main body part (1a) has formed a circuit receiving part (23) within itself; a measuring passage (5) formed on a tip side of the main body part (1a) to cause a portion of the fluid to be measured to flow through it, the measuring passage (5) having a flow rate determination part (6) arranged therein; and a flow rate determination circuit section (8c) is arranged in the circuit receiving section (23) for generating a signal that represents a result of the determination by the flow rate determination section (6), wherein the measuring device (3) for the physical quantity comprises: a determining part (7, 41) for a physical quantity for determining a physical quantity relating to the fluid to be measured in the flow rate measuring device (1); wherein the determining part (7, 41) for a physical quantity comprises a circuit element (705) having an element constant that changes depending on a change in the physical quantity relating to the fluid to be measured; and a physical quantity determination circuit part (8a) arranged in the circuit receiving part (23) for generating a signal obtained by performing a phase correction on a signal representing a result of a determination by the determination part (7, 41) for the physical quantity, wherein the physical quantity determination circuit part (8a) supplies a voltage and a current to the circuit element (705) of the physical quantity determination part (7) for determining the physical quantity and performs a response correction for the phase correction by changing a value of one of the voltage or the current supplied to the circuit element (705) of the physical quantity determination part (7) depending on a variation of the result of the determination by the determination part (7, 41) for the physical quantity.

Description

BACKGROUND OF THE INVENTION 1. Technical Field

[0001] The present invention relates to a flow rate measuring device and the like, which is to be used, for example, to measure an inlet air flow rate and an inlet air temperature of an internal combustion engine, and in particular to a measuring device for a physical quantity and a measuring method for measuring a physical quantity of a fluid, which is to be measured simultaneously with a certain value of the flow rate measuring device. 2. Description of the state of the art

[0002] In a fuel injection control system for an internal combustion engine, the intake air flow rate is the most important piece of information for determining the optimal fuel injection quantity. Furthermore, physical properties of the intake air, such as intake air temperature and absolute humidity, are used to correct the fuel injection control and ignition timing, and are crucial for improving the precision of the internal combustion engine's control. In this context, a physical quantity measuring device integrated with a flow rate measuring device can reduce the assembly workload and the number of components, thereby achieving a reduction in size and cost through the integrated design of the flow rate measuring device and the physical quantity measuring device.In such a prior art flow rate measuring device, which includes an inlet air temperature determination device for determining the inlet air temperature, which is a physical quantity of the inlet air, a device is known in which a flow rate detection device for measuring a flow rate in a measuring passage is arranged for taking in part of the inlet air in the measuring passage, and an inlet air temperature detection element for measuring the inlet air temperature is arranged in the measuring passage or a main passage.

[0003] A semiconductor element incorporating a flux rate detection component formed from a thin film with a thickness on the order of one micrometer is used as the flux rate detection element. Additionally, a thermistor is used as the inlet air temperature detection element.

[0004] A support element is generally provided to mount the inlet air temperature detection element. However, heat transferred by the support element affects the accuracy of the inlet air temperature measurement. Furthermore, using a support element with low thermal conductivity makes it difficult to reduce costs.

[0005] Consequently, the following setups and signal processing were proposed as a flow rate measurement device that can simultaneously improve the precision of the inlet air temperature measurement, reduce costs, and provide high robustness and high reliability.

[0006] In a prior art flow rate measuring device, an inlet air temperature detection element is arranged in a curved measuring passage and connector connections and support connections are separated from each other, thereby reducing the influence of the heat transferred from the support element to the detection element (for example, reference is made to the Japanese patent application with publication number JP 2001-124606 A).

[0007] Furthermore, in a prior art flow rate measuring device, the flow rate detection element and the inlet air temperature detection element are arranged and integrated on a single substrate, thereby reducing costs.

[0008] Furthermore, in a detection element in which the flow rate detection element and the inlet air temperature detection element are formed on a single substrate, the heat capacities of the inlet air temperature detection element and the support element, which includes a substrate part on which the inlet air temperature detection element is arranged, are reduced by forming the inlet air temperature detection element on a membrane, thereby improving a response rate to the inlet air temperature.

[0009] Furthermore, a voltage applied to the inlet air temperature detection element is pulse-driven to reduce the influence of self-generated heat from the inlet air temperature detection element, thereby improving the inlet air temperature measurement precision (for example, reference to Japanese patent application with publication number JP 2006-138688 A).

[0010] As described above, prior art flow rate measuring devices propose setups and signal processing to improve the detection precision of the inlet air temperature detection element. However, according to Japanese patent applications JP 2001-124606 A and JP 2006-138688 A, a problem exists in the flow rate measuring device: if the inlet air temperature detection element is located in a measurement passage or circuit receiving part with a high heat capacity, this can cause a delay in the response to a change in the inlet air temperature in a main passage. Therefore, improving the inlet air temperature measurement precision of the inlet air temperature detection element itself does not result in the desired inlet air temperature precision.

[0011] Furthermore, in the physical quantity measuring device according to Japanese patent number JP 4650082 B2, the measured model value, which is the ideal value of the physical quantity, must be calculated based on information that is different from that provided by the measuring device for measuring the physical quantity of the object to be measured, and consequently, the problem exists that a large number of evaluation works are needed to correct for the precision and variation of the physical quantity information required to calculate the measured model value.

[0012] Furthermore, a computing device with high signal processing capability is needed to calculate the measured model value, and consequently, there is a problem that it is difficult to reduce costs. PRESENTATION OF THE INVENTION

[0013] The present invention was made to solve the above-mentioned problems and therefore aims to provide a physical quantity measuring device integrally mounted with a flow rate measuring device and a physical quantity measuring method for increasing a response rate to a physical quantity that includes an input air temperature by performing phase-guide processing on a physical quantity signal that is measured by a determining element for determining the physical quantity, thereby simultaneously realizing a high-precision physical measuring device and a reduction in costs.

[0014] According to one embodiment of the present invention, a physical quantity measuring device is provided which is integrally mounted with a flow rate measuring device and the like to measure a physical quantity, wherein the flow rate measuring device comprises: a main body part extending inwards from an outside of a main passage of a fluid to be measured, the main body having a circuit receiving section formed within it; a measuring passage formed at a tip side of the main body part to cause a portion of the fluid to be measured to flow through it, the measuring passage having a flow rate determination part formed therein;and a flow rate determination circuit section is arranged in the circuit receiving section to generate signal processing that represents a result of a determination by the flow rate determination section, wherein the physical quantity measuring device includes: a physical quantity determination section for determining a physical quantity relating to the fluid to be measured in the flow rate measuring device; and a physical quantity determination circuit section arranged in the circuit receiving section for generating a signal obtained by performing a phase-guide correction on a signal that represents a result of a determination by the physical quantity determination section.

[0015] According to one embodiment of the present invention, a high-precision and inexpensive physical quantity measuring device, integrally mounted with a flow rate measuring device, and a physical quantity measuring method can be provided, which have an improved response speed to changes in the physical quantity in the fluid, in which the phase guidance correction is performed by the physical quantity determination circuit part on the physical quantity signal from the physical quantity determination part. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 is a cross-sectional view perpendicular to a main passage to show a state in which a flow rate measuring device, including a physical quantity measuring device according to a first embodiment of the present invention, is mounted on the main passage. Fig. Figure 2 is a cross-sectional view viewed parallel to the main passage to show a state in which the flow rate measuring device including the measuring device for a physical quantity according to the first embodiment of the present invention is mounted on the main passage. Fig. Figure 3 is a circuit drawing to illustrate a schematic configuration of the flux rate measuring device including the measuring device for a physical quantity according to the first embodiment of the present invention. Fig. Figure 4 is a cross-sectional view of a main part perpendicular to the main passage, representing a defining element of Fig. 1 and its surroundings. Fig. Figure 5 is a cross-sectional view of the main part parallel to the main passage to illustrate the defining element of Fig. 1 and its surroundings. Fig. Figure 6 is a graph to show a response characteristic of an input air temperature determination part according to the first embodiment of the present invention. Fig. Figure 7 is a graph showing a response delay time of the input air temperature determination part according to the first embodiment of the present invention. Fig. Figure 8 is a graph showing the response characteristic of the inlet air temperature determination section when a flow rate of Fig. 7 is tall. Fig. Figure 9 is a graph to show a frequency characteristic of a digital filter according to the first embodiment of the present invention. Fig. Figure 10 is a cross-sectional view perpendicular to a main passage to show a defining element part and a proximity thereof according to a second embodiment of the invention. Fig. Figure 11 is a cross-sectional view parallel to the main passage to show the determining element part and its proximity according to the second embodiment of the present invention. Fig. Figure 12 is a circuit diagram for representing a schematic configuration of a flux rate measuring device including a measuring device for a physical quantity according to the second embodiment of the present invention. Fig. Figure 13 is a graph showing a response characteristic of a determining part for relative humidity according to the second embodiment of the present invention. Fig. Figure 14 is a graph to show a response characteristic of a temperature determination part according to the second embodiment of the present invention. Fig. Figure 15 is a circuit diagram for representing a schematic configuration of a flux rate measuring device including a measuring device for a physical quantity according to a third embodiment of the present invention. Fig. Figure 16 is a graph to show a response characteristic of an input air temperature determination part according to the third embodiment of the present invention. Fig. Figure 17 is a diagram showing an example of a configuration of a recursive digital filter for performing phase control processing by a digital filter in the measuring device for a physical quantity according to the present invention. Fig. Figure 18 is a diagram showing an example of a configuration for performing phase control processing while a constant current value in a voltage conversion part in the measuring device for a physical quantity is changed, according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED VERSIONS First version

[0016] Referring to Fig. 1 to Fig. Section 9 below describes a measuring device for a physical quantity that is integrally mounted with a flow rate measuring device according to a first embodiment of the present invention. In the following description, for example, the fluid to be measured is an inlet air and the physical quantity is the temperature of the inlet air.

[0017] Fig. 1 and Fig. Figure 2 are diagrams for representing a state in which a flow rate measuring device 1 including the measuring device for a physical quantity according to the first embodiment is introduced and mounted in a main passage 2 of a pipe 100 through which the fluid to be measured flows. Fig. 1 is a cross-sectional view (cross-sectional view extending along line A1-A1 from Fig. 2 was done) perpendicular to a flow direction (CD of Fig. 2) of the fluid to be measured in the main passage 2. Fig. 2 is a cross-sectional view (cross-sectional view along line A2-A2 of Fig. 1) parallel to the flow direction CD in which the fluid to be measured flows.

[0018] Fig. Figure 3 is a circuit diagram to represent a schematic configuration of a determining part of the flow rate measuring device 1, which integrally includes an inlet air temperature measuring device 3, which is the measuring device for the physical quantity.

[0019] Fig. Figure 4 is a cross-sectional view perpendicular to the flow direction of the fluid to be measured, in the same main passage 2 as that of Fig. 1 to represent a determining element part 4 of Fig. 1 and its vicinity.

[0020] Fig. Figure 5 is a cross-sectional view parallel to the flow direction of the fluid to be measured, in the same main passage 2 as that of Fig. 2 to represent the determining element part 4 of Fig. 1 and its vicinity. For example, a main flow of the fluid to be measured flows in a direction indicated by arrow CD. Fig. 2 is indicated.

[0021] Fig. Figure 6 is a graph to show an effect of an improvement in the response speed of an input air temperature determination part 7 of the input air temperature measuring device 3 according to the first embodiment.

[0022] Fig. Figure 7 is a graph showing the response delay time of the inlet air temperature determination part 7 with respect to a change in the flow rate.

[0023] Fig. Figure 8 is a graph to show a response characteristic of the inlet air temperature determination part 7 when the flow rate is large.

[0024] Fig. Figure 9 is a graph to show a frequency characteristic of a digital filter.

[0025] As in Fig. 1 and Fig. Figure 2 shows the flow rate measuring device 1 installed on the pipe 100 and used to measure the flow rate and temperature of the fluid to be measured in the pipe 100. The flow rate measuring device 1 consists of a main body part 1a on a base 10, where a flat plate part is fixed to the pipe 100 and inserted into it, and a measuring passage forming part 1b on a tip section side that is inserted into the pipe 100.

[0026] The main body part 1a extends to an inner side of the main passage 2, through which the fluid to be measured flows, and a circuit receiving part 23 is formed within the main body part 1a. A measuring passage 5 for causing a portion of the fluid to be measured to flow through it is formed in the measuring passage-forming part 1b.

[0027] A plate 9 serves as a support body, extending over the main body part 1a and the measurement passage-forming part 1b. The plate 9 supports a printed circuit board 8 of the circuit mounting part 23 in the main body part 1a and supports a substrate 16, which has the detection element part 4 mounted on it and forms a wall surface of the measurement passage 5 in the measurement passage-forming part 1b. In a portion of the plate 9 that forms the wall surface of the measurement passage 5, the tuning element part 4, in which the inlet air detection part 7 for detecting the temperature of the fluid to be measured, and a flow rate detection part 6 for determining the flow rate of the fluid to be measured are formed on the same main surface of the substrate 16.

[0028] Furthermore, as in Fig. 1 and Fig. As shown in Figure 4, a flat surface of the plate 9, which serves as the wall surface portion of the measuring passage 5, is arranged in the main passage 2 to be parallel to the flow direction of the main passage 2. Furthermore, as shown in Fig. 1 and Fig. 2 shown, the flow rate measuring device 1 is fixed to the pipe 100, so that the main body part 1a is above the measuring passage forming part 1b.

[0029] A detailed description of the flow rate measuring device 1 according to the present invention is given below. Fig. 1 to Fig. 5. The main passage 2 is an internal passage of the pipe 100, for example, in a cylindrical shape, through which the fluid to be measured flows. For example, in the case of an internal combustion engine for a vehicle, the main passage 2 is essentially a flow passage of an intake air pipe, which is integrally formed with an intake air filter device (not shown). Additionally, the fluid to be measured is, for example, a gas such as air. An insertion hole 100b for inserting the flow rate measuring device 1 for measuring the fluid to be measured in the main passage 2 is formed on a flanged part 100a of the pipe 100.

[0030] The flow rate measuring device 1 includes: the measuring passage 5, which is arranged in the main passage 2, to cause a portion of the fluid to be measured to flow through it; the determining element part 4, in which the flow rate determining part 6 for determining the flow rate of the fluid to be measured flowing through the measuring passage 5, and the inlet air temperature determining part 7 for measuring the temperature of the fluid to be measured, are formed on the same substrate 16; the circuit board 8, on which a control circuit for driving the flow rate determination part 6 and the inlet air temperature determination part 7, in order to evaluate a flow rate determination signal and an inlet air temperature determination signal, is formed; the plate 9 for holding the determining element part 4 and the circuit board 8; the base 10 to support the plate 9; a measuring passage forming cover 11, which is arranged at one end of the plate 9 on opposite sides of the base 10 to be opposite the plate 9, for forming the measuring passage 5; and a cover 36 which is arranged at the base 10 of the plate 9 to be opposite the plate 9 in order to form the circuit receiving part 23 for receiving the printed circuit board 8.

[0031] As shown in the cross-sectional view perpendicular to the flow direction of the fluid to be measured, from Fig. 4 shown and in the cross-sectional view parallel to the flow direction of the fluid to be measured, from Fig. 5 includes the determination element part 4, the flow rate determination part 6 and the inlet air temperature determination part 7.

[0032] The flow rate determination part 6 includes a heat-generating resistor 602 for detecting the flow rate of the fluid to be measured, temperature determination resistors 603 for generated heat are each arranged on a current upstream and a current downstream side of the fluid to be measured of the heat-generating resistor 602, and a temperature compensation resistor 604 for detecting the temperature of the fluid to be measured performs a temperature compensation for the flow rate determination.

[0033] The inlet air temperature determination part 7 includes an inlet air temperature determination resistor 705 for determining the temperature of the fluid to be measured.

[0034] The flow rate determination part 6 and the inlet air temperature determination part 7 are, for example, formed on a surface of the substrate 16 in a rectangular flat plate shape, and input / output connections 16a are electrically connected to the heat-generating resistor 602, the temperature determination resistors 603 for generated heat, the temperature compensation resistor 604 and the inlet air temperature determination resistor 705 at a corner of the surface of the substrate 16 and are connected to the circuit board side 8.

[0035] In this case, the heat-generating resistor 602, the temperature-determining resistors 603 for generated heat, the temperature compensation resistor 604, the inlet air temperature-determining resistor 705, and the inlet / outlet terminals 16a are formed by structuring a heat-sensitive resistive film made of platinum, nickel, iron, nickel alloy, titanium, molybdenum, and the like on the surface of the substrate 16. Furthermore, the flow rate determination section 6, which is a formation area for the heat-generating resistor 602, the temperature-determining resistors 603 for generated heat, and the temperature compensation resistor 604, has a membrane structure constructed by a depression formed by removing material from a rear surface of the substrate 16.

[0036] Furthermore, an electrical insulating material such as silicone or ceramic is used as a material for the substrate 16. It should be noted that the inlet air temperature measuring section 7, which is a formation area for the inlet air temperature measuring resistor 705, may have a membrane structure constructed by a recess formed by removing substrate 16 from the rear surface in the same manner as that of the flow rate measuring section 6. Moreover, the inlet air temperature measuring section 7 is formed on the same substrate as that for the flow rate measuring section 6; however, it may be formed on a substrate that is independent of that of the flow rate measuring section 6.

[0037] Furthermore, as shown in the circuit diagram of the flux rate measuring device 1 of Fig. As shown in Figure 3, the printed circuit board 8 includes a constant voltage power supply 17, a transistor 18, fixed resistors 19, an operational amplifier 20 and a constant current source 21 as components and forms an input air temperature determination circuit part 8a, a heat-generating resistance temperature control circuit part 8b, a flux rate determination circuit part 8c and a printed circuit board temperature determination circuit part 8d (described in more detail later), which is a determination circuit part of a physical quantity within a circuit.

[0038] The input air temperature determination circuit section 8a includes a voltage converter section 8a1 for supplying a current from the constant current source 21 to the input air temperature determination resistor 705 of the input air temperature determination section 7 in order to convert the current into a voltage, an analog / digital (A / D) converter section 8a2 for converting a voltage signal from the voltage converter section 8a1, which is an analog signal, into a binary digital signal, and an input air temperature signal adaptation section 8a3 for adapting the digital signal by following a desired output characteristic that has been previously set.

[0039] The flux rate determination circuit section 8c includes a flux rate signal adaptation section 8c1 for adapting an input voltage by following a desired output characteristic that has been previously set.

[0040] The printed circuit board temperature determination circuit section 8d includes a printed circuit board temperature determination section 8d1 for determining a temperature of the printed circuit board 8 and a printed circuit board temperature signal adaptation section 8d2 for adapting an input signal that represents the measured temperature by following a desired output characteristic that has been previously set.

[0041] Plate 9 is made of a plastic material, for example, in a rectangular, flat plate shape. The circuit mounting part 23 is formed by attaching the cover 36 in the region corresponding to the printed circuit board 8, such that the cover 36 faces a surface of plate 9 on which the printed circuit board 8 is located. Furthermore, a measuring element mounting part 24 is formed by attaching the cover 11, which forms the measuring passage. Measuring passage 5 (including 5a to 5g) is formed in the region corresponding to the substrate 16. Measuring element part 4 (including the flow rate measuring part 6 and the inlet air temperature measuring part 7) is specifically arranged in the measuring element part 4, such that the cover 11, which forms the measuring passage, faces a surface of the plate on which the substrate 16 is located.

[0042] More precisely, the substrate 16 is designed to extend towards the side of the circuit mounting part 23, thereby enabling the connection between the input / output terminals 16a and the circuit board 8.

[0043] The printed circuit board 8 is received in the printed circuit board receiving section 23 and is fixed using an adhesive. The substrate 16, which has the measuring element part 4 mounted on it, is received in the measuring element receiving section 24, such that the input / output connections 16a are located on the side of the printed circuit board 8 and are fixed to the plate 9 using an adhesive. It should be noted that the measuring element receiving section 24 is part of the measuring passage 5 and refers to an area in which the measuring element part 4 is located. Furthermore, the printed circuit board 8 and the measuring element part are located on the same surface as the surface (a main surface or inner surface) of the plate 9.

[0044] As in Fig. Figure 1 shows that the base 10 for fixing the flow rate measuring device 1 to the pipe 100 includes a connected part 10a, which is to be connected to the flange part 100a of the pipe 100 to ensure an airtight seal when the flow rate measuring device 1 is inserted into the main passage 2; a connector part 10b (which includes the inserted conductor 10c) which is arranged inside the connector part 10a to communicate signals between the circuit board 8 and the outside of the pipe; and a coupling part 10d which is to be coupled to the circuit receiving part 23, which is arranged from the connector part 10b to the side of the pipe 100. The base 10 is integrally formed so that the connected part 10a, the connector part 10b, and the coupling part 10d surround the insertion conductor 10c and the like by using a plastic such as polybutylene terephthalate.

[0045] The circuit mounting part 23 for receiving the printed circuit board 8 is configured to be surrounded by the plate 9 and the cover 36. An outer end of the plate 9 is fixed to the base 10 by adhesion. The substrate 16, which has the locating element mounted on it, and the printed circuit board 8 are mounted on the plate 9. The substrate 16, which has the locating element 4 mounted on it, is arranged to extend from the locating element mounting part 24 to the side of the circuit mounting part 23. The input / output terminals 16a of the substrate 16 and the input / output terminals 8aa of the printed circuit board 8 are exposed to the inside of the circuit mounting part 23 and are electrically connected to each other by means of attached cables BW or the like.

[0046] Furthermore, the cover 11, which forms the measuring passage, is formed together with the plate 9 by a plastic such as polybutylene terephthalate to create the measuring passage 5. An inner surface of the cover 11, which forms the measuring passage, is fixed to an inner surface of the plate 9, which extends from the base 10 by means of an adhesion promoter or the like. A recess for the measuring passage 5 is formed in the inner surface of the cover 11, which forms the measuring passage. The measuring passage 5, which has a cross-sectional area in, for example, a rectangular shape, is then formed by bonding the cover 11, which forms the measuring passage, to the plate 9. It should be noted that the base 10, the plate 9, and the cover 11, which forms the measuring passage, can be integrally formed by a plastic or the like.

[0047] As in Fig. Figure 2 shows that the measuring passage 5 comprises a flow inlet 5a, a first passage section 5b, a first curved section 5c, a second passage section 5d, a second curved section 5e, a third passage section 5f in which the determining element section 4 is arranged, a third curved section 5g, a fourth passage section 5h, and a flow outlet section 5i, and is designed in a curved shape. The flow inlet 5a is open near the tip section of the flow rate measuring device 1 (end opposite the connector section 10b) to a stream side in the flow direction CD of the main flow of the fluid to be measured, causing the fluid to flow into the measuring passage 5.The flow outlet 5i opens a tip-section end surface of the flow rate measuring device 1 in a direction perpendicular or approximately perpendicular to the flow direction CD, causing the fluid to be measured to flow from the measuring passage 5 to the side of the main passage 2. In other words, the end surface of the flow rate measuring device 1 at the tip-section side is a surface that is parallel or approximately parallel to the flow rate direction CD.

[0048] The flow in measurement passage 5 is described in more detail below. The first passage section 5b is configured to extend from the flow inlet 5a to reach the first curved section 5c in the flow direction CD of the main flow of the fluid to be measured. The second passage section 5d is configured to extend from the first curved section 5c to reach the second curved section 5e towards the circuit board 8 in a direction that is orthogonal or approximately orthogonal to the flow direction CD. The fourth passage section 5h is configured to extend from the third curved section 5g to reach the flow outlet 5i away from the circuit board 8 in a direction that is orthogonal or approximately orthogonal to the flow direction CD.The first curved section 5c, the second curved section 5e and the third curved section 5g are designed to bend the flow direction of the fluid to be measured at right angles or approximately right angles.

[0049] Furthermore, as in Fig. 5 shows the formation area of ​​the heat-generating resistance 602, the two temperature determination resistances 603 for generated heat and the temperature compensation resistance 604 of the flow rate determination part 6 of the determination element part 4 and the formation region of the inlet air temperature determination resistance 705 of the inlet air temperature determination part 7 to the inside of the third passage part 5f of the measuring passage 5 exposed.

[0050] As in Fig. As shown in Figure 2, each of the multiple insertion conductors 10c is form-fitted into the base 10, such that one end of it is exposed within the circuit receiving part 23 and the other end is exposed within the connector part 10b. Furthermore, as shown in Fig. As shown in Figure 5, the input / output terminals 16a of the determining element part 4 are arranged on the substrate 16, and the input / output terminals 8aa of the printed circuit board 8 are connected by means of the connecting cables BW cable. Furthermore, the input / output terminals 8aa of the printed circuit board 8 and one end of the insertion connector 10a are connected by means of the connecting cables BW cable. Note that cable connection is described as one example of an electrical connection method, but a method for electrical connection such as welding or soldering can also be used.

[0051] The plastic cover 36 is adhered to the circuit mounting part 23 by using an adhesion promoter applied to an outer groove of the circuit mounting part 23 (more precisely, with reference to Fig. 1, Fig. 2 and Fig. 4 are respective corner sections of side surface elements on both sides of the plate 9, extending in a direction orthogonal to the plate 9, the cover 11 forming the measuring passage, and the coupling part 10d), in order to close an opening of the circuit receiving part 23. Note that the method for closing the opening described is an example of adhesion by using an adhesion promoter, but a method such as welding can be used. In addition, although not shown, sealing gel is filled into the circuit receiving part 23.

[0052] This type of flow rate measuring device 1 is formed from the main body part 1a, in which a base part of an extended section, extending from the base 10, is formed from the base 10, wherein the plate 9 includes the side surface elements and the cover 36 is attached to the side surface elements, and the measuring passage-forming part 1b is formed by the plate 9 and the cover, which forms the measuring passage and is attached to the plate. The base part of the extended section is formed in a rectangular cuboid shape, with the main body part 1a (and the measuring passage-forming part 1b) having a rectangular cross-sectional shape that is orthogonal to its direction of extension. Furthermore, the main body part 1a and the measuring passage-forming part 1b are included in a projecting surface of the connected part 10a in the direction of extension.

[0053] As described above, the main body part 1a and the measurement passage forming part 1b are rectangular in cross-section perpendicular to the direction of extension, and a wall surface on one side is a longer side of a rectangular outer perimeter thereof, corresponding to a rear surface of the plate 9, and the other wall surface corresponds to an external surface of the cover 36 and the measurement passage forming cover 11.

[0054] Furthermore, the flow inlet 5a of the measuring passage 5 is formed on a side surface which is orthogonal to the direction of extension on the shorter side of the rectangular outer environment of the cross-section of the measuring passage forming part 1b and which is located on an upstream side of the main passage 2 in the vicinity of the flow outlet 5i of the measuring passage 5. The flow outlet 5i of the measuring passage 5 is formed at a position downstream of the flow inlet 5a of the main passage 2 on the end surface parallel to the flow direction CD of the tip section of the plate 9.

[0055] As in Fig. As shown in Figure 1, the flow rate measuring device 1 is inserted into the insertion hole 100b, so that the main body part 1a extends into the main passage 2 and is mounted to the flange part 100a of the pipe 100 by fixing the connected part 10a to a flange form of the base 10 with screws 38.The flow rate measuring device 1 is inserted into the main passage 2 such that wall surfaces on the longer sides of the rectangular outer environment of the cross-section are perpendicular to the direction of extension of the main body part 1a (the same applies to the measuring passage-forming part 1b) and parallel to or approximately parallel to the flow direction CD of the main stream of the fluid to be measured flowing through the main passage 2, and one of the wall surfaces formed from the shorter sides of the rectangular outer environment of the cross-section of the main body part 1a faces the upstream side to be orthogonal or approximately orthogonal to the flow direction CD. Then, as in . Fig. Figure 1 shows an O-ring 10e inserted between the coupling part 10d and the insertion hole 100b to ensure airtightness.

[0056] The flow inlet 5a of the measuring passage 5 opens on the surface facing the upstream side and is orthogonal to the flow direction CD of the main stream, and the flow outlet 5i opens a surface facing downwards and is parallel to the flow direction CD of the main stream.

[0057] The fluid to be measured then flows through the main passage 2, from the flow inlet 5a into the measuring passage 5, flows along the flow direction CD of the main flow in the first passage section 5b, is bent approximately at a right angle in the first curved section 5c, and flows in a direction approximately orthogonal to the flow direction CD of the main flow in the second passage section 5d. The flow direction of the fluid to be measured is then bent approximately at a right angle through the second curved section 5e, and the fluid to be measured flows in the flow direction CD of the main flow into the third passage section 5f, which is the measuring position, and flows along the surface of the determining element section 4.The flow direction of the fluid to be measured is then bent by approximately a right angle through the third bent part 5g, and the fluid to be measured flows in a direction approximately orthogonal to the flow direction CD of the main stream into the fourth passage part 5h and is discharged from the flow outlet 5a to the main passage 2.

[0058] Then, as in Fig. As shown in Figure 2, an external electrical power is supplied from the connector part 10b to the control circuit, which is constructed on the circuit board 8, via the inserted conductors 10c. Fig. As shown in Figure 3, this control circuit is formed from the input air temperature determination circuit part 8a, the heat-generating resistance temperature control circuit part 8b, the flux rate determination circuit part 8c and the printed circuit board temperature determination circuit part 8d.

[0059] As in Fig. As shown in Figure 3, the input air temperature determination circuit part 8a, the voltage converter part 8a1, directs the current from the constant current source 21 to the input air temperature determination resistor 705, which is arranged on the input air temperature determination part 7, of the determination element part 4 and changes its resistance value depending on the temperature in order to determine a voltage signal depending on the temperature.

[0060] The A / D converter section 8a2 converts the voltage signal determined by the voltage converter section 8a1 into the binary digital signal.

[0061] The input air temperature signal adaptation section 8a3 uses a digital filter DF to perform phase-guide processing and calculates a temperature difference based on the temperature difference between the circuit board temperature 8, as measured by the circuit board temperature detection section 8d, and the input air temperature, as measured by the A / D converter section 8a2. It then adapts the input air temperature signal to a predetermined characteristic and outputs the input air temperature signal as an input air temperature signal (IAT) from the output terminal. The digital filter DF changes its filter constants depending on a signal determined by the flux rate detection section 8c and also includes a low-pass filter function (LPF) for attenuating high-frequency signals.

[0062] Then, as in Fig. As shown in Figure 17, phase control processing can be implemented by the digital filter DF using recursive digital filters that have a configuration of infinite impulse response filters using multipliers 8ML1 to 8ML5, adders 8AD1 to 8AD4 and delay circuits 8DL1 to 8DL4.

[0063] In the recursive digital filter of Fig. 17. Input signals are in principle delayed in the delay circuits 8DL1 to 8DL4 and then multiplied with respective coefficients in the multipliers 8ML1 to 8ML5 and added together with the adders 8AD1 to 8AD4 to output the sum.

[0064] Frequencies f0, f1 and f2 of Fig. 9 can be determined by values ​​of coefficients a0, a1, a2, b1 and b2 of the multipliers 8ML1 to 8ML5, which are filter constants that are in Fig. 17 are shown.

[0065] Furthermore, an optimal frequency characteristic of the digital filter DF, which has the low-pass filter function for attenuating a high-frequency signal, can be obtained by changing the values ​​of the filter constants a0, a1, a2, b1 and b2 based on a flux rate signal FLA, in order to adjust the frequencies f0, f1 and f2 of Fig. 9 to change. A description is given above the recursive digital filter, which has the configuration of infinite impulse response filters, but the recursive digital filter can be designed as a finite impulse response filter.

[0066] The heat-generating resistor temperature control circuit section 8b forms a bridge circuit using the heat-generating resistor 602 and the temperature compensation resistor 604, which are connected to the flux rate determination section 6 of the determination element section 4 and the fixed resistors 10 of the printed circuit board 8. A differential signal from the circuit is then determined by the operational amplifier. Feedback control, ensuring a constant generated temperature, is achieved by supplying a current from the constant voltage source 17 to bridge the circuit via the transistor 18, which is controlled by the differential signal.

[0067] The flux rate determination circuit section 8c forms a bridge circuit using two temperature determination resistors 603 for the generated heat. These resistors are arranged upstream and downstream, respectively, in the flux direction CD of the main current of the heat-generating resistor 602, which is connected to the flux rate determination section 6 of the determination element section 4. The resistance values ​​of the heat-generating resistor 602 change depending on the heat generated by the heat-generating resistor 602, the fixed resistors 19 of the circuit board 8, and the constant voltage source 17 (heat-generating resistor of a flux meter type). A differential signal corresponding to the flux rate is then determined by the bridge circuit. This differential signal is fed to the flux rate signal adaptation section 8c1.The difference signal is then adjusted by the flow rate signal adjustment section 8c1 to exhibit the characteristic that was previously set and is output as the flow rate signal (FLA) from the output connector.

[0068] Furthermore, the flow rate signal adaptation part 8c1 performs the input air temperature correction on the flow rate signal (FLA) based on the input air temperature signal (IAT) from the input air temperature signal adaptation part 8a3 of the input air temperature determination circuit part 8a.

[0069] It should be noted that if the flow rate signal adaptation section 8c1 is implemented as a digital circuit, as in the input air temperature signal adaptation section 8a3, an analog-to-digital conversion is applied to the input signal. If the flow rate signal adaptation section 8c1 is implemented as an analog circuit, the signal is transmitted to the input air temperature signal adaptation section 8a3 after an analog-to-digital conversion.

[0070] In the printed circuit board temperature detection circuit part 8d, the printed circuit board temperature detection part 8d1 supplies a current from the constant current source 21 to the printed circuit board temperature detection resistor 801, which is arranged on the printed circuit board 8, which changes its resistance value depending on the temperature and converts the current into a voltage, thereby obtaining the voltage signal.

[0071] The printed circuit board temperature signal adaptation part 8d2 adapts the supplied voltage signal to exhibit the characteristic that is previously selected and outputs the adapted voltage signal to the input air temperature determination circuit part 8a as a printed circuit board temperature signal CBT.

[0072] Note that if the PCB temperature signal adaptation section 8d2 is a digital circuit, as in the input air temperature signal adaptation section 8a3, an analog-to-digital conversion is first applied to the input signal. If the PCB temperature signal adaptation section 8d2 is an analog circuit, the signal is transmitted to the input air temperature signal adaptation section 8a3 after an analog-to-digital conversion.

[0073] The input air temperature signal adaptation part 8a3 input air temperature determination circuit part 8a compares the printed circuit board temperature signal CBT and the input air temperature signal IAT with each other and, if a temperature difference occurs, corrects the input air temperature signal IAT.

[0074] For example, the correction is achieved by amplifying the difference between the input air temperature signal (IAT) and the circuit board temperature signal (CBT) using a differential amplifier, converting the amplified signal into a digital signal using an A / D conversion, multiplying the digital signal by a coefficient using a multiplier, and adding the multiplied signal to the input air temperature signal to which phase guidance processing has been applied by an adder.

[0075] It should be noted that the printed circuit board temperature detection section 8d1 is formed by supplying current from the constant current source 21 to the printed circuit board temperature detection resistor 801, but can also be formed by short-circuiting between the base and the collector of a transistor, supplying a current from the constant current source to the collector of the transistor and supplying a voltage between the base and the emitter of the transistor to the printed circuit board temperature signal adaptation section 8d2.

[0076] Fig. Figure 6 is a graph showing a response characteristic of the inlet air temperature determination circuit part 8a of the flow rate measuring device 1 according to the first embodiment of the present invention and shows a change in temperature determined by the inlet air temperature determination part 7 and caused by a change in the temperature of the fluid to be measured.

[0077] The change in temperature is caused in a case where a vehicle is placed in a heated garage from an environment with a low atmospheric temperature, and the incoming air temperature quickly rises from a low temperature; or in a case where a vehicle's hood is closed from an open position, hot air is drawn into the engine compartment as the incoming air, and the incoming air temperature quickly rises. Furthermore, in a case where an engine is warmed up in an idling state and the vehicle is rapidly accelerated after the temperature in the engine compartment has risen, the incoming air temperature quickly drops from a high temperature.

[0078] The dashed line A of Fig. Figure 6 represents the temperature in the main passage 2 when the temperature of the fluid to be measured changes and represents a waveform to be measured in the measurement passage 5, namely a short-term change in temperature. The solid line B represents data (input air temperature signal (IAT)) acquired by the input air temperature measuring device 3 according to the present invention, including the phase correction function for the input air temperature signal (ITA) and the temperature difference correction function between the input air temperature (IAT) and the circuit board temperature (CBT) by the digital filter DF in the input air temperature signal adaptation part 8a3.The alternating long and short line C shows comparison data (input temperature signal) when the phase guidance correction and the temperature difference correction between the input air temperature (IAT) and the circuit board temperature (CBT) were not performed by the digital filter DF.

[0079] The alternating long and short dashed line C indicates a state in which the time to reach equilibrium is longer than that of the dashed line A and the solid line B, and the equilibrium temperature is the lowest. In other words, the inlet air temperature measuring device 3, which uses the digital filter DF to perform phase correction on the inlet air temperature signal and temperature difference correction between the inlet air temperature and the circuit board temperature according to the present invention, can provide data that is closer to the actual temperature change in the fluid being measured.

[0080] As seen through the alternately long and short stroked line C of Fig. In the flow rate measuring device, where the phase control is not applied to the inlet air temperature signal via the digital filter DF, the temperature in measuring passage 5 increases more slowly than the temperature in main passage 2. This is because the interior of measuring passage 5, which is formed by molds, has a large heat capacity, causing a response delay with respect to the temperature change in the fluid being measured in main passage 2, and the correct inlet air temperature cannot be determined. Furthermore, if the temperature outside pipe 100 is lower than the temperature in main passage 2, even when the temperature change reaches equilibrium, the temperature in measuring passage 5 will remain lower than that in main passage 2. This is because heat conduction from the outside of pipe 100 to the connector part 10b and measuring passage 5 affects measuring passage 5.

[0081] For example, even if the heat capacity of the inlet air temperature determination part 7 of the substrate 16 is reduced, for example by applying the membrane structure for the substrate section of the inlet air temperature determination part 7 of the substrate 16 to increase the response rate to the temperature change in the inlet air temperature determination part 7, an error in the temperature in the measuring flow passage 5 occurs and the correct inlet air temperature cannot be determined.

[0082] According to the first embodiment, the digital filter DF of the input air temperature signal adaptation part 8a3 of the input air temperature determination circuit part 8a can perform phase-guide processing on the signal from the input air temperature determination part 7. As a result of this configuration, as shown by the solid line B of Fig. As shown in Figure 6, the measurement error of the input air temperature signal output from the input air temperature determination circuit section 8a with respect to the temperature at main pass 2, which is the true value, is reduced, and the response time to the temperature change in the fluid being measured can be increased. Furthermore, the phase-guided processing by the digital filter DF eliminates the need for a high-capacity capacitor required for an analog filter, and a significant reduction in costs can be easily achieved. Additionally, by comparing the circuit board temperature and the input air temperature and correcting the input air temperature signal when a temperature difference occurs, the temperature at equilibrium can be brought closer to the temperature at main pass 2.

[0083] Fig. Figure 7 is a graph showing the response delay time of the inlet air temperature determination part 7 in the measurement run 5 with respect to the flow rate when the temperature of the fluid to be measured changes. Fig. 8 is a graph similar to Fig. 6 to show a response characteristic of the inlet air temperature determination circuit part 8a of the flow rate measuring device 1 according to the first embodiment of the present invention, when the flow rate is greater than that of Fig. 6 is.

[0084] As in Fig. Figure 8 shows that when the flow rate is large, heat conduction increases to reduce the response delay of the inlet air temperature in measurement pass 5 and consequently, as shown by a peak indicated by the arrow of the solid line B, the phase guidance correction can be overestimated, resulting in a decrease in measurement precision.

[0085] In this case, a precise response correction to the input air temperature difference can be performed without a decrease in the input air temperature measurement precision by adding a function of changing the filter constant for each flow rate or by adding it to the digital filter DF based on the flow rate.

[0086] For example, the filter constants are changed based on, for example, the flow rate signal (FLA) from the flow rate determination circuit section 8c.

[0087] Furthermore, as in Fig. As shown in Figure 7, when the flow rate is high, the response delay time of the inlet air temperature determination section 7 decreases, and the required measurement precision can be ensured without phase guidance correction. In this case, the amount of data stored for the filter constants can be reduced to further reduce costs by stopping the phase guidance correction function of the digital filter DF at a flow rate equal to or greater than a flow rate that does not require phase guidance correction, depending on the flow rate signal (FLA).

[0088] Furthermore, as can be seen from the frequency characteristics of the digital filter, which is in Fig. Figure 9 shows a high-frequency noise signal, amplified by phase correction, which can be attenuated by adding a low-pass filter function to increase noise tolerance and achieve highly accurate input air temperature measurements. A peak section of the amplification of Fig. 9 corresponds to a lower frequency range and a right side of the peak corresponds to a high frequency range.

[0089] Note that independently of the digital filter DF, a low-pass filter LPF may be arranged, which is implemented by a finite impulse response filter arrangement or is formed from multipliers, adders and delay circuits.

[0090] Furthermore, as in Fig. As shown in Figure 3, the flow rate signal adaptation part 8c1 can realize highly accurate flow rate measurements by using the highly accurate input air temperature information transmitted by the input air temperature signal adaptation part 8a3 to change the characteristic change in the flow rate signal (FLA) caused by the input air temperature. Second embodiment

[0091] With reference to Fig. 10 to Fig. Section 14 describes a physical quantity measuring device that is integrally mounted with a flow rate measuring device according to a second embodiment of the present invention. The basic configuration of the flow rate measuring device, which includes the physical quantity measuring device, is essentially the same as that described in Fig. 1 and Fig. Figure 2 is shown. In the following description, for example, the fluid to be measured is the incoming air, and the physical quantity is the relative humidity and temperature of the incoming air to obtain the absolute humidity of the incoming air.

[0092] Fig. 10 is a cross-sectional view perpendicular to a flow direction of the fluid to be measured, in the main passage 2, which is the same as that of Fig. 1 is to represent a defining element part and a proximity thereof according to the second embodiment.

[0093] Fig. Figure 11 is a cross-sectional view parallel to the flow direction of the fluid to be measured, in the main passage 2, which is the same as that of Fig. 2 is to represent the determining element part 4 and its proximity according to the second embodiment.

[0094] Fig. Figure 12 is a circuit diagram to represent a schematic configuration of a determining part of the flow rate measuring device 1, which includes an inlet air temperature and a humidity measuring device 3a, which is the physical quantity measuring device according to the second embodiment.

[0095] Fig. Figure 13 is a graph to show an effect of an improvement in the response speed of a relative humidity determination part 44 according to the second embodiment.

[0096] Fig. Figure 14 is a graph to show an effect of an improvement in the response speed of a temperature determination part 45 according to the second embodiment.

[0097] As in Fig. 10 and Fig. As described in section 11, the temperature and humidity measuring device, which serves as the physical quantity determination part, is soldered to a cable tie backing surface on the printed circuit board 8. Other electronic components are soldered to the same surface or an opposite surface of the cable tie backing on the printed circuit board 8.

[0098] The temperature and humidity measuring device is arranged in a measuring chamber 42, which is divided by the side surface elements of the circuit mounting part 23 formed on the circuit board 8 and the cover 36. The temperature and humidity measuring device is the only electronic component in the measuring chamber. The circuit board 8 is attached to the base 10 and the cover 36, the cover 36 is attached to the measuring passage forming cover 11, the coupling part 10d of the base 10, and such an assembly, which has the electronic components on the circuit board 8 except for the temperature and humidity measuring device, is inserted separately from the main passage 2.A communication opening 43, open on a surface extending parallel to the direction of the inlet air flow through the main passage 2, is formed on the cover 36, and the measuring chamber 32 and the main passage 2 are connected to each other via the connection opening 43. Furthermore, a coupling element between the temperature and humidity measuring device, the external air, and the circuit board 8, which is coated with a coating material, is exposed. The remaining configuration is the same as that of the first embodiment.

[0099] The temperature and humidity measuring device is used to measure the absolute humidity of the incoming air. It measures the relative humidity and temperature at the point where the relative humidity is measured, thereby calculating the absolute humidity. If contaminants such as water or oil adhere directly to the measuring part of the temperature and humidity measuring device, the measurement accuracy decreases, and in the worst case, the measurement cannot be performed. Therefore, the humidity and temperature measuring device must be located in measuring chamber 42, into which foreign materials (contaminants) are not very likely to enter, as shown in Fig. Figure 10 is shown. However, although it is not likely that foreign objects will enter, it is also not likely that air will enter at the main passage side 2 and that such a problem, which decreases the measurement precision of relative humidity and temperature, will exist.

[0100] For example, absolute humidity rises rapidly when a vehicle enters a tunnel in a highly humid environment. Conversely, when the vehicle leaves the tunnel, absolute humidity drops rapidly.

[0101] Fig. Figure 12 is a circuit diagram illustrating a schematic configuration of the determining part according to the second embodiment of the present invention. As in Fig. As shown in Figure 12, the temperature and humidity measuring device of the inlet air temperature and humidity measuring device (physical quantity measuring device) 3a is formed from a relative humidity determination section 44 and a temperature determination section 45. The relative humidity determination section 44 of the temperature and humidity measuring device determines the relative humidity. The phase control processing is applied to a determination signal by the digital filter DF of a temperature and humidity signal adaptation section 8e, which forms a temperature and humidity determination circuit section. The determination signal is adapted to have a predetermined characteristic and is output as an inlet air humidity signal (RHU) from the output terminals.

[0102] Furthermore, the temperature determination section 45 of the temperature and humidity measuring device determines the temperature, phase-guided processing is applied to a determination signal by the digital filter of the temperature and humidity signal adaptation section 8e, and the determination signal is adapted to exhibit a predetermined characteristic and is output as a specific input air temperature signal (TEP) from the output terminals. For example, the phase-guided processing is performed by recursive digital filters located in Fig. 17 are depicted, trained.

[0103] The other configurations and actuators are the same as or correspond to those of the first embodiment.

[0104] Fig. Figure 13 is a graph showing a response characteristic of the relative humidity determination part 44 of the temperature and humidity measuring device according to the second embodiment of the present invention and shows a change in relative humidity determined by the relative humidity determination part 44 caused by a change in the relative humidity of the fluid to be measured.

[0105] The dashed line A of Fig. Figure 13 represents the relative humidity in the main passage 2 as the relative humidity of the fluid to be measured changes, and represents a waveform to be measured in the measuring chamber 42, namely a temporal change in relative humidity. The solid line B represents data (relative humidity signal (RHU) of the inlet air) obtained by the inlet air temperature and humidity measuring device 3a, which incorporates the phase correction function for the relative humidity signal through the digital filter DF in the temperature and humidity signal adaptation section 8e. The alternating long and short dashed line C represents comparative data (relative humidity signal) obtained when the phase correction is not performed by the digital filter DF.

[0106] The alternating long and short dashed line C represents a state in which the time until equilibrium is reached is greater than that of the dashed line A and the solid line B. In other words, the inlet air temperature and humidity measuring device 3a according to the invention, which uses the digital filter DF to perform the phase correction on the relative humidity signal, can provide data that are closer to the actual humidity change in the fluid being measured.

[0107] Fig. Figure 14 is a graph showing a response characteristic of the temperature determination part 45 of the temperature and humidity measuring device and shows a change in temperature determined by the temperature determination part 45 caused by a change in the temperature of the fluid to be measured.

[0108] The dashed line A of Fig. Figure 14 represents the temperature in the main passage 2 when the temperature of the fluid to be measured changes, and represents a waveform to be measured in the measuring chamber 42, namely a change in temperature over time. The solid line B represents data (a specific inlet air temperature signal (TEP)) obtained by the inlet air temperature and humidity measuring device 3a, which incorporates the phase-guided correction function for the temperature signal via the digital filter DF and the temperature and humidity signal adaptation section 8e. The long dashed line represents comparative data (temperature signal) obtained when the phase-guided correction was not performed by the digital filter.

[0109] The alternating long and short dashed line C represents a state in which the time until equilibrium is reached is greater than that of the dashed line A and the solid line B. In other words, the inlet air temperature and humidity measuring device 3a according to the present invention, which uses the digital filter DF to perform the phase correction on the temperature signal, can provide data that are close to the actual temperature change in the fluid to be measured.

[0110] The temperature and humidity measuring device has been described, but the same effect can be provided for other physical quantities by this measuring device. Third embodiment

[0111] With reference to Fig. 15 and Fig. Section 16 below describes a measuring device for a physical quantity which is integrally mounted with a flow rate measuring device according to a third embodiment of the present invention. In the following description, for example, the fluid to be measured is inlet air and the physical quantity is the temperature of the inlet air.

[0112] Fig. Figure 15 is a circuit diagram for representing a schematic configuration of a determining part of a flow rate measuring device 1, which integrally includes an inlet air temperature measuring device (measuring device for a physical quantity) 3 according to the third embodiment.

[0113] Fig. Figure 16 is a graph to show an effect of an improved response speed of the inlet air temperature determination part 7 of the inlet air temperature measuring device 3 according to the third embodiment.

[0114] As in Fig. As shown in Figure 15, the voltage converter section 8a1 is arranged in the input air temperature determination circuit section 8a for supplying the current from the constant current source 21 to the input air temperature determination resistor 705 on the input air temperature determination section 7 of the determination element section 4. The resistance value of the resistor changes depending on the temperature and converts the current into a voltage signal. Subsequently, the voltage converter section 8a1 determines the voltage signal according to the temperature, and the determined voltage signal is converted into the digital signal by the A / D converter section 8a2.

[0115] An input air temperature signal adaptation part 8a4 has a function for performing the phase guidance processing through the digital filter DF, which corrects the temperature difference correction processing based on the temperature difference between the temperature of the printed circuit board 8 from the printed circuit board temperature determination circuit part 8d and the input air temperature from the A / D converter part 8a2 and then adapts the input air temperature signal to have the predetermined characteristic, which is to be output as the input air temperature signal IAT from the output terminal.

[0116] Furthermore, the input air temperature signal adaptation section 8a4 has a function for outputting a signal to the voltage converter section 8a1, which is obtained by differentiating the input air temperature signal ITA and multiplying the derivative by a coefficient. The voltage converter section 8a1 modifies a current value supplied to the input air temperature determination section 7, depending on a signal obtained by differentiating the input air temperature signal from the input air temperature signal adaptation section 8a4 and multiplying the derivative by the coefficient.The above described the case in which the input air temperature determination part 7 is formed only from the input air temperature determination resistor 705, but an input air temperature determination resistor 705a can be designed as a transition state determination circuit element independently of the input air temperature determination resistor 705 in order to perform the phase correction for the input air temperature signal.

[0117] Fig. Figure 16 is a graph showing a response characteristic of the inlet air temperature determination part 7 of the inlet air temperature measuring device 3 according to the third embodiment and shows a change in temperature determined by the inlet air temperature determination part 7 caused by a change in the temperature of the fluid to be measured.

[0118] The dashed line A of Fig. 16 represents the temperature in the main pass 2 when the temperature of the fluid to be measured changes and represents a waveform to be measured in the measurement pass 5, namely a change in temperature over time.

[0119] The solid line B represents data (inlet air temperature (IAT)) obtained by the inlet air temperature measuring device 3 according to the present invention, which has the current phase correction function of providing the instantaneous value obtained by differentiating the signal from the inlet air temperature determination part 7 or the inlet air temperature signal IAT obtained by the inlet air temperature signal adaptation part 8a4, and multiplying the derivative by a coefficient on the inlet air temperature determination part 7 and the temperature difference correction function between the inlet air temperature (IAT) and the printed circuit board temperature (CBT).

[0120] The long-dash, double-short-dash line D represents data that shows a signal obtained by differentiating the signal from the inlet air temperature determination part 7.

[0121] The alternating long and short dashed line C represents comparative data obtained when the phase correction and temperature difference correction were not performed. The alternating long and short dashed line C represents a state in which the time to reach equilibrium is longer than that of the dashed line A and the solid line B. In other words, the inlet air temperature measuring device 3 according to the present invention, which performs the phase correction on the inlet air temperature signal by changing the current supplied to the inlet air temperature determination part 7 depending on an intermediate state, can provide data that closely reflect an actual temperature change in the fluid being measured.

[0122] As in the alternating long and short dashed line C of Fig. As shown in Figure 16, in the inlet air temperature measuring device, where the phase guide correction is not applied to the inlet air temperature signal, the temperature in the measuring passage 5 increases more slowly than the temperature in the main passage 2. This is because the inside of the measuring passage 5, which is formed by shapes, has such a large heat capacity that it causes a response delay with respect to the temperature change in the fluid to be measured in the main passage 2, and the correct inlet air temperature cannot be determined.

[0123] According to the third embodiment, the phase-guide processing can be performed by adding the instantaneous value obtained by the input air temperature signal adaptation section 8a4 of the input air temperature determination section 8a, differentiating the signal from the input air temperature determination section 7, and multiplying the derivative by the coefficient of the constant instantaneous value of the voltage converter section 8a1, which is supplied to the input air temperature determination section 7. Furthermore, the coefficients can be changed depending on the flow rate signal FLA from the flow rate signal adaptation section 8c1 of the flow rate measuring device 1, so that the phase-guide correction amount is an optimal value for each flow rate. For example, the input air temperature determination circuit section 8a is formed from a circuit that is in Fig. 18 is shown.

[0124] In the circuit of Fig. 18 is an AC component of the voltage obtained from the input air temperature measuring resistor 705a, extracted by a circuit consisting of a capacitor C and a resistor R of the voltage conversion section 8a1, and converted to analog-to-digital conversion by the A / D conversion section 8a2. The converted A / D signal is multiplied by a coefficient by a multiplier 88ML and converted to digital-to-analog conversion by a D / A conversion section 88CO1. The converted A / D signal is amplified by an amplifier 88AM and fed into a current mirror circuit consisting of three transistors TR and a resistor R. As a result, a constant current value from the constant current source 21 is adjusted as a function of the current flowing through the resistor.

[0125] As a result of this configuration, as shown by the solid line B of Fig. As shown in Figure 16, the input air temperature output from the input air temperature determination circuit part 8a exhibits a reduced measurement error with respect to the temperature in the main passage 2, which is the true value, and the response rate to the temperature change in the fluid to be measured can be improved.

[0126] Note that the case described is where the inlet air temperature sensing section 7 consists solely of the inlet air temperature sensing resistor 705. However, the inlet air temperature sensing resistor 705 for measuring the inlet air temperature and another inlet air temperature sensing resistor 705 for determining the change in inlet air temperature can be formed on the inlet air temperature sensing section 7. The current, corrected by the value obtained by differentiating the inlet air temperature signal from the other inlet air temperature sensing resistor 705a and multiplying the derivative by the coefficient, can be supplied to the inlet air temperature sensing resistor 705. As a result of this configuration, the phase-guide correction for the inlet air temperature is not positive feedback, thus preventing overcorrection to improve the precision of the inlet air temperature measurement.

[0127] Furthermore, the respective embodiments describe the case in which current is supplied to the inlet air temperature measuring resistor 705 to determine the inlet air temperature. However, a physical quantity can be determined by supplying a current or voltage to a circuit element other than the resistor, such as a capacitor or an inductor, which changes its respective constants depending on a change in the physical quantity relating to the fluid to be measured, such as temperature. In addition, the inlet air temperature has been described as an example of the physical quantity, but the same effect can be achieved by a measuring device for a physical quantity by supplying a current or voltage to the determining element of the physical quantity in order to determine the physical quantity.

[0128] It should be noted that the present invention is not limited to the respective embodiments, but includes all possible combinations thereof.

[0129] Furthermore, for illustrative purposes, in Fig. 3, Fig. 12 and Fig. 15 the inlet air temperature determination part 7 and the temperature and humidity measuring device 41, which form the determination part for the physical quantity, each shown in the inlet temperature measuring device 3 and the inlet air and humidity measuring device 3a, which forms the measuring device for the physical quantity, as in Fig. 4, Fig. 5, Fig. 10 and Fig. As shown in Figure 11, the inlet air temperature determination part 7 and the temperature and humidity measuring device 41 are mounted in the flow rate measuring device 1, namely in the measuring passage 5 and a part of the circuit receiving part 23 of the main body part 1a.

Claims

[1] Physical quantity measuring device (3) integrally mounted with a flow rate measuring device (1) for measuring a physical quantity, wherein the flow rate measuring device (1) comprises: a main body part (1a) extending inwards from an outside of a main passage of a fluid to be measured, wherein the main body part (1a) has formed a circuit receiving part (23) within itself; a measuring passage (5) formed on a tip side of the main body part (1a) to cause a portion of the fluid to be measured to flow through it, the measuring passage (5) having a flow rate determination part (6) arranged therein; and a flow rate determination circuit section (8c) is arranged in the circuit receiving section (23) for generating a signal that represents a result of the determination by the flow rate determination section (6), wherein the measuring device (3) for the physical quantity comprises: a determining part (7, 41) for a physical quantity for determining a physical quantity relating to the fluid to be measured in the flow rate measuring device (1); wherein the determining part (7, 41) for a physical quantity comprises a circuit element (705) having an element constant that changes depending on a change in the physical quantity relating to the fluid to be measured; and a physical quantity determination circuit part (8a) arranged in the circuit receiving part (23) for generating a signal obtained by performing a phase correction on a signal representing a result of a determination by the determination part (7, 41) for the physical quantity, wherein the physical quantity determination circuit part (8a) supplies a voltage and a current to the circuit element (705) of the physical quantity determination part (7) for determining the physical quantity and performs a response correction for the phase correction by changing a value of one of the voltage or the current supplied to the circuit element (705) of the physical quantity determination part (7) depending on a variation of the result of the determination by the determination part (7, 41) for the physical quantity. [2] Physical quantity measuring device integrally mounted with a flux rate measuring device according to claim 1, wherein the physical quantity determination circuit part (8a) comprises a digital filter for performing phase guidance correction. [3] Physical quantity measuring device integrally mounted with a flow rate measuring device according to claim 1 or 2, wherein the physical quantity determination circuit part (8a) changes a correction quantity for the phase guidance correction depending on a result of a determination of a flow rate by the flow rate determination circuit part (8c). [4] Physical quantity measuring device integrally mounted with a flow rate measuring device according to any one of claims 1 to 3, wherein the physical quantity determination circuit part (8a) avoids performing the phase guidance correction if a result of a determination of a flow rate by the flow rate determination circuit part (8c) is greater than or equal to a predetermined flow rate for which the phase guidance correction is unnecessary. [5] Physical quantity measuring device integrally mounted with a flux rate measuring device according to one of claims 1 to 4, wherein the physical quantity determination circuit part (8a) has a low-pass filter function. [6] Physical quantity measuring device integrally mounted with a flux rate measuring device according to any one of claims 1 to 5, wherein the physical quantity determination circuit part (8a) sets a value obtained by differentiating a signal of the physical quantity determined by the circuit element of the determination part for the physical quantity and multiplies the derivative by a coefficient as a correction quantity for one from the voltage and current supplied to the physical quantity determination part (7). [7] Physical quantity measuring device integrally mounted with a flow rate measuring device, according to any one of claims 1 to 5, wherein: the determining part (7) for a physical quantity includes a transition state determining circuit element (705a) for determining a transition state of the physical quantity; and the physical quantity determination circuit part (8a) sets a value obtained by differentiating a signal of the physical quantity determined by the transition state determination circuit element (705) of the determination part (7) for the physical quantity, and multiplies the derivative by a coefficient as a correction quantity for one from the voltage and current supplied to the transition state determination circuit element (705) of the determination part (7) for the physical quantity. [8] Physical quantity measuring device integrally mounted with a flow rate measuring device according to claim 6 or 7, wherein the physical quantity determination circuit part (8a) changes the coefficients depending on a flow rate determined by the flow rate determination circuit part (8c). [9] Physical quantity measuring device integrally mounted with a flow rate measuring device, according to any one of claims 1 to 8, wherein: the determining part (7) for the physical quantity is arranged in the measuring passage (5); the physical quantity measuring device (3) further comprises an intra-circuit physical quantity determination circuit part (8d) for determining a physical quantity of the same kind as the physical quantity in the circuit receiving part; and the physical quantity determination circuit part (8a) corrects the physical quantity by the phase guidance correction and a difference correction for a physical quantity for the physical quantities that are determined by the determination part (7) for physical quantities and the intra-circuit physical quantity determination circuit part (8d). [10] Physical quantity measuring device integrally mounted with a flow rate measuring device according to any one of claims 1 to 9, wherein the flow rate determination circuit part (8c) corrects a certain flow rate using the physical quantity corrected by the physical quantity determination circuit part (8a). [11] Physical quantity measuring device integrally mounted with a flow rate measuring device according to any one of claims 1 to 10, wherein the physical quantity comprises a temperature of the fluid to be measured in the measuring passage (5) or a relative humidity and a temperature to maintain an absolute humidity of the fluid to be measured within the main body part (1a) of the flow rate measuring device (1). [12] Method for measuring a physical quantity for a physical quantity measuring device (3) which is integrally mounted with a flow rate measuring device (1), wherein, when measuring a physical quantity of a fluid to be measured, to adjust a value determined by the flow rate measuring device (1), the flow rate measuring device (1) which incorporates a flow rate determination circuit part (8c) for generating a signal which is a result of a determination of a flow rate of the fluid to be measured, which is determined by a flow rate determination part (6) in a main body part (1a) which extends inwards from an outside to a main passage of the fluid to be measured, the flow rate measuring device (1) comprises a measuring passage (5) formed on a tip side of the main body part (1a) to cause a portion of the fluid to be measured to flow through it, wherein the measuring passage (5) has the flow rate determination part (6) arranged therein, the physical quantity measuring device comprising: a determining part (7) for the physical quantity, comprising a circuit element (705) having an element constant that changes depending on a change in the physical quantity relating to the fluid to be measured; and a physical quantity determination circuit part (8a) which supplies a voltage and a current to the circuit element (705) of the physical quantity determination part (7) for determining the physical quantity and performs a response correction for phase guidance by changing a value of one of the voltage or the current supplied to the circuit element of the physical quantity determination part (7) depending on a variation of the result of the determination of the physical quantity, the physical measurement method includes: Determine, by means of the physical quantity measuring device (3) which is integrally mounted with the flow rate measuring device (1), a physical quantity relating to the fluid to be measured in the flow rate measuring device (1); and Performing phase correction by means of the physical measuring device (3) on a signal that represents a result of a determination of the physical quantity.

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