WO2019064908A1 - Physical quantity detection device - Google Patents

Abstract

The present invention is to obtain a physical quantity detection device capable of suppressing thermal influence which is exerted on a sensor and caused by miniaturization. A physical quantity detection device 20 of the present invention is provided with: a chip package 208 in which a flow rate sensor 205 and electronic components are sealed with a resin; and a circuit board 207 on which the chip package 208 is mounted. The chip package 208 is fixed to the board surface of the circuit board 207 while a portion of the chip package protrudes laterally from an end portion of the circuit board 207. The circuit board 207 has a flat blank space region S which is wider than the width of the chip package 208 at a position on the board surface and at a position deviated in a direction opposite to the protrusion direction of the chip package 208.

Description

Physical quantity detection device

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

In Patent Document 2, a measurement portion protrudes from the inner wall of the intake passage toward the center of the passage, and the intake temperature sensor is connected to a connector by a lead, and the configuration of the thermal flow meter disposed on the upstream side is shown There is.

JP, 2010-145155, A

In the conventional device described in Patent Document 1, although the intake air temperature sensor is connected to the connector by the lead and directly contacts air, the distance is short to the connector terminal which is a heat source, and heat is easily transmitted to the sensor from the measurement unit. The thermal effect on the sensor may be large, which may affect the reliability of the heat dissipation of the sensor and the detection accuracy.

The present invention has been made in view of the above-described point, and an object of the present invention is to be able to arrange an intake air temperature sensor at a position where air flow is accelerated, and to improve intake air temperature detection accuracy. It is an object of the present invention to provide a physical quantity detection device that can

The physical quantity detection device of the present invention which solves the above-mentioned subject is
A physical quantity detection device for detecting a physical quantity of a gas to be measured which flows in a main passage, which has an intake temperature sensor and a flow rate sensor, and is provided upstream of an inlet opening of a subpassage where the flow rate sensor is disposed The intake air temperature sensor is provided between the wall and an inlet opening of the sub passage.

According to the present invention, the intake air temperature sensor can be disposed at a position where the air flow is accelerated by the upstream side wall portion. Accordingly, it is an object of the present invention to provide a physical quantity detection device which can be disposed at a position where the flow velocity is high to improve the heat radiation performance and thus to improve the intake temperature detection accuracy.
Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. Further, problems, configurations and effects other than those described above will be clarified by the description of the following embodiments.

1 is a system diagram showing an embodiment using a physical quantity detection device according to the present invention in an internal combustion engine control system. The front view of a physical quantity detection apparatus. Rear view of physical quantity detection device. The left view of a physical quantity detection device. The right view of a physical quantity detection apparatus. FIG. 2 is a plan view of a physical quantity detection device. The bottom view of a physical quantity detection device. The figure explaining the result of having measured the flow velocity of the to-be-measured gas of physical quantity detection apparatus periphery. The other Example of the inhalation | air-intake temperature sensor structure of a physical-quantity detection apparatus. IVA-IVA sectional view taken on the line of FIG. 2E. FIG. 6 is a view for explaining the flow of resin at the time of resin molding in the flange of the present embodiment. The figure corresponded to FIG. 4A in a comparative example. The figure explaining the flow of resin at the time of resin molding in the flange of a comparative example. The front view of the housing in the state from which the cover was removed. VIB-VIB sectional view taken on the line of FIG. 6A. A numerical graph showing the allowable temperature error of each sensor. The graph which showed the temperature change of each sensor in the engine room. The front view of the housing from which the cover was removed. The front view of a circuit board. VIIIC-VIIIC sectional view taken on the line of FIG. 8B. The front view of the housing from which the cover and the board | substrate were removed. IXB-IXB sectional view taken on the line of FIG. 9A. IXC-IXC sectional view taken on the line of FIG. 9A. The front view of the circuit board in which the chip package and the circuit component were mounted. XB-XB sectional view taken on the line of FIG. 10A. The XC-XC line sectional view of Drawing 10A. The figure which shows the substrate sheet | seat in which the circuit board shown to FIG. 10A was formed in multiple numbers. The figure which expands and shows the XIB part of FIG. 11A. The XIC-XIC line sectional view of Drawing 11B. The figure which shows the substrate sheet in which the circuit board of the comparative example was formed in multiple numbers. Front view of chip package. Rear view of chip package. The left side view of a chip package. Right side view of the chip package. The bottom view of a chip package. The front view of the circuit board in which the circuit component is not mounted.

The mode for carrying out the invention (hereinafter referred to as an example) to be described below solves various problems demanded as an actual product, and in particular, as a detection device for detecting a physical quantity of intake air of a vehicle It solves various problems that are desirable to use and has various effects. One of the various problems solved by the following embodiments is the content described in the column of the problems to be solved by the above-described invention, and one of the various effects exhibited by the following embodiments is: It is an effect described in the column of the effect of the invention. Regarding various problems solved by the following embodiments, various effects exerted by the following embodiments will be further described in the description of the following embodiments. Accordingly, the problems and effects that the embodiments solve are described in the following embodiments are also described for contents other than the contents of the columns of the problems to be solved by the invention and the effects of the invention.

In the following embodiments, the same reference numerals indicate the same configuration even if the drawing numbers are different, and the same effects are achieved. With regard to the configuration that has already been described, the drawings may be given only reference numerals and descriptions thereof may be omitted.

FIG. 1 is a system diagram showing an embodiment using a physical quantity detection device according to the present invention in an electronic fuel injection type internal combustion engine control system 1. Based on the operation of the internal combustion engine 10 provided with the engine cylinder 11 and the engine piston 12, intake air is drawn from the air cleaner 21 as the gas 2 to be measured, and the main passage 22 is, for example, an intake body, a throttle body 23 and an intake manifold 24. It is led to the combustion chamber of the engine cylinder 11 via the same. The physical quantity of the to-be-measured gas 2 which is the intake air introduced to the combustion chamber is detected by the physical quantity detection device 20 according to the present invention, and fuel is supplied from the fuel injection valve 14 based on the detected physical quantity. It is led to the combustion chamber in the state of air-fuel mixture with 2. In the present embodiment, the fuel injection valve 14 is provided at the intake port of the internal combustion engine, and the fuel injected into the intake port forms an air-fuel mixture with the gas 2 to be measured, and is introduced to the combustion chamber via the intake valve 15 He burns to generate mechanical energy.

The fuel and air introduced to the combustion chamber are in a mixed state of fuel and air, and are sparkly burned by spark ignition of the spark plug 13 to generate mechanical energy. The gas after combustion is guided from the exhaust valve 16 to the exhaust pipe, and is exhausted as exhaust gas 3 from the exhaust pipe to the outside of the vehicle. The flow rate of the to-be-measured gas 2 which is the intake air introduced to the combustion chamber is controlled by the throttle valve 25 whose opening degree changes based on the operation of the accelerator pedal. The amount of fuel supplied is controlled based on the flow rate of the intake air introduced to the combustion chamber, and the driver controls the opening degree of the throttle valve 25 to control the flow rate of the intake air introduced to the combustion chamber. The mechanical energy generated by the engine can be controlled.

<Overview of Control of Internal Combustion Engine Control System>
A physical quantity such as flow rate, temperature, humidity, pressure and the like of the gas to be measured 2 which is intake air taken in from the air cleaner 21 and flows through the main passage 22 is detected by the physical quantity detection device 20 and electricity representing the physical quantity of intake air from the physical quantity detection device 20 A signal is input to the controller 4. Further, the output of the throttle angle sensor 26 for measuring the opening degree of the throttle valve 25 is input to the control device 4, and the positions and states of the engine piston 12, the intake valve 15, and the exhaust valve 16 of the internal combustion engine, and the rotation of the internal combustion engine The output of the rotation angle sensor 17 is input to the controller 4 in order to measure the speed. The output of the oxygen sensor 28 is input to the control device 4 in order to measure the state of the mixing ratio of the fuel amount and the air amount from the state of the exhaust gas 3.

The control device 4 calculates the fuel injection amount and the ignition timing based on the physical quantity of the intake air, which is the output of the physical quantity detection device 20, and the rotational speed of the internal combustion engine measured based on the output of the rotational angle sensor 146. Based on these calculation results, the amount of fuel supplied from the fuel injection valve 14 and the ignition timing to be ignited by the spark plug 13 are controlled. The fuel supply amount and the ignition timing are actually based on the temperature and the change of the throttle angle detected by the physical quantity detection device 20, the change of the engine rotational speed, and the air-fuel ratio measured by the oxygen sensor 28. It is finely controlled. Further, in the idle operation state of the internal combustion engine, the control device 4 controls the amount of air bypassing the throttle valve 132 by the idle air control valve 27, and controls the rotational speed of the internal combustion engine in the idle operation state.

The fuel supply amount and the ignition timing, which are main control amounts of the internal combustion engine, are both calculated using the output of the physical quantity detection device 20 as a main parameter. Therefore, it is important to improve the detection accuracy of the physical quantity detection device 20, to suppress the change with time, and to improve the reliability with respect to the improvement of the control accuracy of the vehicle and the maintenance of the reliability.

In particular, in recent years, the demand for fuel efficiency of the vehicle is very high, and the demand for purification of exhaust gas is very high. In order to meet these demands, it is extremely important to improve the detection accuracy of the physical quantity of the intake air 2 detected by the physical quantity detection device 20. It is also important that the physical quantity detection device 20 maintain high reliability.
The vehicle on which the physical quantity detection device 20 is mounted is used in an environment where the change in temperature and humidity is large. In the physical quantity detection device 20, it is preferable that the response to changes in temperature and humidity in the use environment, and the response to dust, contaminants, and the like are also considered.

Further, the physical quantity detection device 20 is mounted on an intake pipe that is affected by heat generation from the internal combustion engine. Therefore, the heat generation of the internal combustion engine is transmitted to the physical quantity detection device 20 through the intake pipe which is the main passage 22. The physical quantity detection device 20 detects the flow rate of the gas to be measured by performing heat transfer with the gas to be measured, so it is important to suppress the influence of external heat as much as possible.

The physical quantity detection device 20 mounted on a vehicle only solves the problems described in the section of the problem to be solved by the invention, as described below, and only exhibits the effects described in the section of the effects of the invention. Instead, as described below, the various issues described above are sufficiently taken into consideration, and the various issues required for the product are solved to achieve various effects. Specific problems to be solved by the physical quantity detection device 20 and specific effects to be exhibited will be described in the description of the following embodiments.

<Appearance structure of physical quantity detection device>
2A to 2F are views showing the appearance of the physical quantity detection device. In the following description, it is assumed that the gas to be measured flows along the central axis of the main passage.
The physical quantity detection device 20 is inserted into the inside of the main passage 22 from a mounting hole provided in the passage wall of the main passage 22 and used. The physical quantity detection device 20 includes a housing 201 and a cover 202 attached to the housing 201. The housing 201 is configured by injection molding a synthetic resin material, and the cover 202 is configured by a plate-like member made of a conductive material such as an aluminum alloy, for example. The cover 202 is formed in a thin plate shape and has a wide flat cooling surface.

The housing 201 has a flange 211 for fixing the physical quantity detection device 20 to the intake passage, which is the main passage 22, and a connector that protrudes from the flange 211 and is exposed to the outside from the intake passage to electrically connect with an external device. A measuring portion 213 extends from the flange 211 so as to project toward the center of the main passage 22.

The measuring unit 213 has a thin and long shape extending from the flange 211 toward the center of the main passage 22, and has a wide front surface 221 and a back surface 222, and a pair of narrow side surfaces 223 and 224. The measuring unit 213 protrudes from the inner wall of the main passage 22 toward the center of the main passage 22 with the physical quantity detection device 20 attached to the main passage 22. The front surface 221 and the back surface 222 are disposed in parallel along the central axis of the main passage 22, and one of the narrow side surfaces 223 and 224 of the measuring unit 213, the side surface 223 on one side in the short direction of the measuring unit 213 is the main passage. The side surface 224 of the other side in the short direction of the measurement unit 213 is disposed opposite to the upstream side of the main passage 22.

In the measurement unit 213, as shown in FIG. 2F, the front surface 221 of the measurement unit 213 is flat from the side surface 223 on one side to the side surface 224 on the other side along the shorter direction. In the reference numeral 222, the corner is chamfered, and is inclined in the direction to gradually approach the front as it moves from the latitudinal middle position to the other side 224, and its cross-sectional shape is so-called streamlined . Therefore, the to-be-measured gas 2 which flowed from the upstream of the main passage 22 can be smoothly led downstream along the front surface 221 and the back surface 222, and the fluid resistance with respect to the to-be-measured gas 2 can be made small.

The lower surface of the measuring unit 213 is formed in a step-like shape at the tip of the measuring unit 213, and the lower surface of the one side disposed on the upstream side of the main passage 22 with the physical quantity detection device 20 attached to the main passage 22 226 and a lower surface 227 of the other side disposed downstream of the main passage 22, and the lower surface 227 of the other side protrudes further than the lower surface 226 of the one side, and the lower surface 226 of one side and the other side A step surface 228 connecting between the lower surface 227 and the lower surface 227 is disposed to face the upstream side of the main passage 22. Then, on the step surface 228 of the measuring unit 213, an inlet 231 for taking in a part of the gas to be measured 2 such as the intake air into the sub passage in the measuring unit 213 is opened and provided. Then, at the side surface 224 on the other side in the short side direction of the measurement unit 213 and at a position facing the step surface 228, the first measurement gas 2 taken into the sub passage in the measurement unit 213 is returned to the main passage 22. An outlet 232 and a second outlet 233 are provided open.
That is, the measuring unit 213 is configured such that the first wall (side surface 223 on one side) oppositely disposed toward the upstream side in the flow direction of the measured gas 2 in the main passage 22 and the measuring unit 213 than the first wall. A second wall portion (opposite side) facing the flow direction upstream of the gas to be measured 2 at the downstream side of the main passage 22 in the flow direction of the main channel 22 and having the inlet 231 of the sub passage open And a step surface 228).

In the physical quantity detection device 20, the entrance 231 of the sub passage is provided at the tip of the measurement unit 213 extending from the flange 211 toward the center direction of the main passage 22. The gas close to the central part away from the wall surface can be taken into the side passage. For this reason, the physical quantity detection device 20 can measure the flow rate of the gas in a portion away from the inner wall surface of the main passage 22, and can suppress the decrease in measurement accuracy due to the influence of heat or the like.

In the vicinity of the inner wall surface of the main passage 22, it is susceptible to the temperature of the main passage 22, and the temperature of the gas to be measured 2 becomes different from the original temperature of the gas. It will be different from the state. Particularly when the main passage 22 is the intake body of the engine, it is often maintained at a high temperature under the influence of heat from the engine. For this reason, the gas in the vicinity of the inner wall surface of the main passage 22 is often higher than the original air temperature of the main passage 22, which causes the measurement accuracy to be lowered. Further, in the vicinity of the inner wall surface of the main passage 22, the fluid resistance is large, and the flow velocity becomes lower than the average flow velocity of the main passage 22. For this reason, when the gas in the vicinity of the inner wall surface of the main passage 22 is taken into the sub passage as the gas 2 to be measured, a decrease in flow velocity relative to the average flow velocity of the main passage 22 may lead to measurement error.

The physical quantity detection device 20 is provided with the inlet 231 at the tip of the thin and long measurement unit 213 extending from the flange 211 toward the center of the main passage 22. Therefore, the measurement error related to the flow velocity decrease near the inner wall surface is reduced it can. Further, the physical quantity detection device 20 not only is provided with the inlet 231 at the tip of the measurement portion 213 extending from the flange 211 toward the center of the main passage 22 but also the first outlet 232 and the second outlet 233 of the sub passage. Also, the measurement error can be further reduced because it is provided at the tip of the measurement unit 213.

The physical quantity detection device 20 has a shape in which the measurement unit 213 extends along an axis from the outer wall of the main passage 22 toward the center, but the widths of the side surfaces 223 and 224 are as shown in FIGS. 2C and 2D. , Has a narrow shape. As a result, the physical quantity detection device 20 can suppress the fluid resistance to a small value for the measured gas 2.

<Structure of Temperature Detection Unit>
In the physical quantity detection device 20, as shown in FIG. 2B, an intake air temperature sensor 203, which is a temperature detection unit, is provided at the tip of the measurement unit 213. The intake air temperature sensor 203 is provided so as to be exposed outside the measuring unit 213. Specifically, in the flow direction of the measurement gas 2, it is disposed at a position downstream of the side surface on one side of the measurement unit 213 and at a position upstream of the step surface 228 of the measurement unit 213. An inlet 231 of the sub passage is provided so as to open on the step surface 228 of the measuring unit 213, and the intake air temperature sensor 203 is disposed upstream of the inlet 231 of the sub passage.

The intake air temperature sensor 203 is provided exposed outside the measurement unit 213 and disposed upstream of the entrance 231 of the sub passage, so the intake temperature sensor 203 is disposed in the sub passage of the measurement unit 213 In this case, the influence on the flow rate measurement of the flow rate sensor 205 provided in the auxiliary passage is smaller than in the case where

The intake air temperature sensor 203 is constituted by an axial lead component having a cylindrical sensor body 203a and a pair of leads 203b protruding from both axial ends of the sensor body 203a in a direction away from each other. The intake air temperature sensor 203 is mounted on the circuit board 207 in the measurement unit 213 via the lead 203b, and as shown in FIG. 2F, the lead insertion hole 216 opened in the lower surface 226 on one side of the measurement unit 213 is The sensor main body 203 a is disposed at a position where the pair of leads 203 b protrudes from the lower surface 226 on one side of the measurement unit 213 and faces the step surface 228 of the measurement unit 213. The intake air temperature sensor 203 is disposed in parallel along the lower surface 226 on one side of the measurement unit 213 and in a direction along the flow direction of the measurement gas 2.

The intake air temperature sensor 203 is exposed to the outside of the measurement unit 213 in a state where the sensor main body 203 a is supported by the pair of leads 203 b, so the measurement unit 213 includes a protector 202 a for protecting the intake air temperature sensor 203. Better to form. The protector 202 a protrudes from the lower surface of the measurement unit 213 and is disposed to face the front side of the measurement unit 213 with respect to the intake temperature sensor 203. In the present embodiment, an example in which a part of the cover 202 is made to project from the lower surface of the measuring unit 213 is shown, but a shape may be formed to make the housing 201 project. By providing the protector 202a, it is possible to prevent the intake air temperature sensor 203 from directly contacting another object at the time of transportation, work, etc. of the physical quantity measuring device.

Further, the protector 202a also functions as a rectifying member that exerts a rectifying effect, so that it is possible to suppress the disturbance of the flow due to the fluid hitting the intake temperature sensor 203. Therefore, the disturbance of the flow can be suppressed from entering the sub-passage 234 in which the flow rate sensor 205 is mounted, and the influence on the flow rate sensor 205 when the intake temperature sensor 203 is disposed upstream of the inlet 231 of the sub-passage 234 Can be suppressed. In particular, when the response is improved by arranging the sensor body 203a of the intake air temperature sensor 203 on the opening projection surface of the inlet 231, which is a fast-flowing point, the sensor body 203a flows in the fast-flowing point. It is more preferable to suppress the influence on the flow rate sensor 205 by providing the intake temperature sensor 203 by rectifying the flow to suppress the disturbance of the flow.

The protruding length of the protector 202a can be arbitrarily selected. For example, when the intake air temperature sensor 203 is disposed at a position largely separated from the lower surface 226 on one side of the measurement unit 213, the tip of the protector 202a is disposed to at least the same position as the intake air temperature sensor 203. The protrusion length is set. Further, when the intake air temperature sensor 203 is disposed in the vicinity of the lower surface 226 on one side of the measurement unit 213, it contacts another object as compared with the case where the intake temperature sensor 203 is disposed at a large distance from the lower surface 226. Since the possibility of doing so is also reduced, the protector may not be provided.

The measuring unit 213 has a side surface 223 (first wall portion) on one side facing the flow direction upstream side of the gas to be measured 2 in the main passage 22 and a tip of the measuring unit 213 rather than the side surface 223 on one side. The step surface 228 (second step) is disposed opposite to the flow direction downstream of the measurement gas 2 at the position downstream of the main passage 22 in the flow direction of the main passage 22 and the inlet 231 of the sub-passage. And the wall). In other words, the inlet 231 of the sub passage 234 is provided on the tip side (the opposite side of the flange 211) than the first wall 223 and on the downstream side.

The intake air temperature sensor 203 is disposed downstream of the side surface 223 on the one side in the flow direction of the measured gas 2 in the main passage 22 and on the inlet 231 of the sub passage opened in the step surface 228 (second wall). It is disposed at the upstream side of the flow direction of the measurement gas 2 in the passage 22.

When the to-be-measured gas 2 flowing in the main passage 22 collides with the side surface 223 on one side, a separation flow is generated which flows toward the step surface 228 of the measuring unit 213. The separated flow accelerates the flow downstream and on the tip side of the side surface 223 on one side. Since the intake air temperature sensor 203 is disposed in the area corresponding to the accelerated flow, the responsiveness can be improved.

FIG. 3A is a view for explaining the measurement results of the flow velocity of the gas to be measured in the vicinity of the physical quantity detection device. According to the measurement results, the flow velocity is 0.5 m / s or less at points (8) to (14) on the upstream side of the side surface 223 on one side of the measurement unit 213, while one side of the measurement unit 213 The flow velocity is 0.6 m / s or more at points (1) to (7) on the downstream side of the side surface 223 on the side and on the upstream side of the step surface 228 of the measuring unit 213. The flow velocity at the downstream side of the side surface 223 and at the upstream side of the step surface 228 of the measuring unit 213 is higher than the upstream side position of the side surface 223 on one side of the measuring unit 213. This is because the separated flow generated by the collision of the measured gas 2 with the side surface 223 on one side of the measurement unit 213 is downstream of the side surface 223 on one side of the measurement unit 213 and from the step surface 228 of the measurement unit 213 It is presumed that this is also because the flow of the measurement gas 2 at the upstream position is accelerated.

Furthermore, the points (2) to (7) located on the projection plane of the inlet 231 have a flow velocity of 0.7 m / s or more, which is a faster flow. It is presumed that this is a result of the fluid becoming easier to flow because the resistance of the fluid is reduced due to the absence of the wall portion that is an obstacle downstream.
And it is a result which the point (2) and (3) in which the obstacle which becomes a fluid resistance is easy to appear easily by the exfoliation by the 1st wall part 223 and which becomes fluid resistance do not exist in the downstream side is especially excellent. .

According to the physical quantity detection device 20 of the present embodiment, the intake air temperature sensor 203 is not located upstream of the side surface 223 on one side of the measurement unit 213 but on the downstream side of the side surface 223 on one side of the measurement unit 213 And since it arrange | positions in the position of the upstream side rather than the level | step difference surface 228 of the measurement part 213, in addition to the to-be-measured gas 2 which flows straight from an upstream with respect to the intake temperature sensor 203, a peeling flow can also be applied. . Therefore, the heat dissipation of the intake air temperature sensor 203 can be improved.

More preferably, when the sensor body 203a is located on the entrance projection plane, the flow can be restrained from decelerating. In this case, the provision of the rectifying member (protector) is more preferable because the disturbance of the fluid entering the sub passage 234 can be suppressed, and the trade-off with the accuracy with the flow rate sensor 205 is satisfied.

In this embodiment, the acceleration region is formed on the upstream side of the opening 231 of the sub passage 234 in the limited mounting space, and the intake air temperature sensor 203 is mounted in the acceleration region. Therefore, the accuracy is maintained and improved. At the same time, downsizing can be achieved. And since the acceleration of the air taken into the auxiliary passage 234 and the acceleration of the air applied to the intake temperature sensor 203 are performed in the same manner in the first wall portion 223, it contributes to space saving.

Another embodiment of the intake air temperature sensor 203 is shown in FIG. 3B. The arrangement form of the intake air temperature sensor 203 may be not only parallel arrangement (or horizontal arrangement) but also vertical arrangement and oblique arrangement. When it exists on the downstream side of the side surface 223 on one side of the measurement unit 213 and on the upstream side of the step surface 228 of the measurement unit 213, the separated flow can reach the intake temperature sensor 203.

<Structure of flange>
The measuring unit 213 of the physical quantity detection device 20 is inserted into the inside from the attachment hole provided in the main passage 22, the flange 211 of the physical quantity detection device 20 is abutted against the main passage 22, and fixed to the main passage 22 with screws. . The flange 211 has a substantially rectangular shape in plan view having a predetermined thickness, and as shown in FIGS. 2E and 2F, fixing holes 241 are provided in pairs at diagonal corners. There is. The fixing hole portion 241 has a through hole 242 which penetrates the flange 211. The flange 211 is fixed to the main passage 22 by inserting a fixing screw (not shown) into the through hole 242 of the fixing hole portion 241 and screwing it into the screw hole of the main passage 22.

As shown in FIG. 2E, the upper surface of the flange 211 is provided with a plurality of ribs. The rib includes a first rib 243 linearly connecting between the fixing hole portion 241 and the connector 212, a second rib 244 having a tapered cross section surrounding the through hole 242 of the fixing hole portion 241, and a flange 211. A third rib 245 provided along the outer peripheral portion, and a fourth rib 246 extending in a direction crossing the first rib 243 on the diagonal of the flange 211 are provided.

Since the first rib 243 is provided linearly between the fixing hole portion 241 where the screw fixing force to the main passage 22 acts and the connector 212 having a relatively high rigidity due to the three-dimensional shape, the flange reinforcement is The effect is high. Therefore, the thickness of the flange 211 can be reduced as compared with the case in which the first rib 243 is not provided, and the weight reduction of the entire housing can be achieved. The influence of shrinkage of the constituent resin can be reduced.

4A is a cross-sectional view taken along line IIA-IIA of FIG. 2E, FIG. 4B is a view for explaining the flow of resin at the time of resin molding in the flange of this embodiment, and FIG. 5A is a view corresponding to FIG. FIG. 5B is a view for explaining the flow of resin at the time of resin molding in the flange of the comparative example.

The housing 201 is manufactured by injection-molding a resin in a mold, and the resin P flows in the mold at a portion of the flange 211 so as to wrap around the through hole 242 at the time of resin molding. For example, as shown in FIG. 5A, when the thickness around the through hole 242 of the fixing hole 241 is uniform, it is difficult to control the flow of the resin P, and as shown in FIG. When resin P separates and flows in from both sides of through-hole 242, the widthwise central portion advances as the lead, and in the widthwise central portion, the two join first, and the direction in which through-hole 242 approaches and the throughhole The junction is formed to be gradually advanced in a direction away from 242. Therefore, there is a possibility that weak welds (resin junctions) may occur due to insufficient resin junctions at the junctions, and if metal bushes are not used, the durability is low and cracks may occur. there were.

On the other hand, in the present embodiment, as shown in FIG. 4A, the second rib 244 having a tapered cross section is provided around the through hole 242. As shown in FIG. 4B, the second rib 244 is bifurcated at the portion of the through hole 242, and when the resin P flows in from both sides of the through hole 242, the width direction through hole vicinity portion of the resin P flowing in is the head The flow of the resin P is controlled such that the merging is performed only in the direction away from the through hole 242 by causing the merging at the portion first. Therefore, the resin P can be sufficiently joined at the joining portion, and the generation of a fragile weld can be prevented.

The first rib 243 is provided linearly along the diagonal connecting the pair of fixing holes 241, and the fourth rib 246 is provided along the other diagonal. The first rib 243 is formed relatively thick as compared to the fourth rib 246, and the rigidity is high. The third rib 245 is provided with a notch for each side of the flange 211 so as to prevent the liquid from accumulating in the upper surface of the flange 211 and in the region surrounded by the first rib 243 and the third rib 245. It has become.

As shown in FIG. 2E, the connector 212 has four external terminals 247 and correction terminals 248 provided therein. The external terminal 247 is a terminal for outputting a physical quantity such as a flow rate or temperature which is a measurement result of the physical quantity detection device 20, and a power supply terminal for supplying DC power for operating the physical quantity detection device 20. The correction terminal 248 is a terminal used to measure the produced physical quantity detection device 20, obtain a correction value related to each physical quantity detection device 20, and store the correction value in a memory in the physical quantity detection device 20. In the subsequent measurement operation of the physical quantity detection device 20, the correction data representing the correction value stored in the memory described above is used, and the correction terminal 248 is not used. Therefore, the correction terminal 248 has a shape different from that of the external terminal 247 so that the correction terminal 248 does not disturb the connection of the external terminal 247 with another external device. In this embodiment, the correction terminal 248 has a shape shorter than the external terminal 247, and even if the connection terminal to the external device connected to the external terminal 247 is inserted into the connector 212, the connection will not be disturbed. ing.

<Structure of housing>
6A is a front view of the housing with the cover removed, and FIG. 6B is a cross-sectional view taken along line VIB-VIB of FIG. 6A. 6A and 6B, the sealing material for sealing the circuit substrate is omitted.

The housing 201 is provided with a sub-passage groove 250 for forming the sub-passage 234 in the measuring unit 213 and a circuit chamber 235 for accommodating the circuit board 207. The circuit chamber 235 and the auxiliary passage groove 250 are recessed in the front of the measuring unit 213, and are separately arranged on one side and the other side in the short direction of the measuring unit 213.

The circuit chamber 235 is disposed on the upstream side of the main passage 22 in the flow direction of the gas to be measured 2, and the sub passage 234 is on the downstream side of the circuit passage 235 in the flow direction of the measured gas 2 on the main passage 22. Be placed. Further, the circuit board 207 is disposed substantially in parallel with the measurement gas 2 flowing through the main passage 22. As a result, the size in the longitudinal direction and the thickness direction of the measurement unit 213 can be reduced, and a low pressure loss physical quantity detection device can be proposed. In particular, when the detection functions of the intake air temperature sensor 203, the humidity sensor 206, the pressure sensor 205, etc. are multifunctionalized, the size of the circuit board 207 is increased by the increase in the number of control circuits, protection circuits, circuit wiring, and electronic components. Because it is more effective.

A chip package 208 including a flow rate sensor 205 for measuring the flow rate of the measurement target gas 2 flowing through the main passage 124 is accommodated in the housing 201 in a state mounted on the circuit board 207 on which a plurality of sensors can be mounted. There is. FIG. 6A shows an example where a pressure sensor 204, a humidity sensor 206, and an intake air temperature sensor 203 are mounted in addition to the chip package 208. However, since it is not necessary to mount all the sensors depending on the requirements, the necessary sensors may be implemented according to the requirements. The circuit board 207 forms a mounting portion corresponding to all the sensors, and can be used in common with the sensor mounting pattern for each request.

The chip package 208 is fixed to the substrate surface of the circuit board 207 in a state where a part of the chip package 208 protrudes laterally from the end of the circuit board 207. The chip package 208 is disposed between the sub passage 234 and the circuit chamber 235.

Thus, the circuit chamber 235 and the sub passage 234 are separated, and the flow to the flow rate sensor 205 disposed in the chip package 208 can be limited by the shape of the sub passage 234. As a result, there is no barrier in the sub-passage 234 that obstructs the flow, and a stable flow can be supplied to the flow sensor 205. Therefore, it is possible to miniaturize the measuring unit 213 while maintaining the flow velocity sensitivity, noise performance and pulsation characteristic of the flow sensor.
By setting the upstream side wall portion of the circuit chamber 235 as the side surface 223 on one side, space saving can be realized.

In this embodiment, the flow sensor 205 is disposed on the chip package 208 and mounted on the circuit board 207. However, the flow sensor 205 may be mounted via a support other than the chip package 208. Good. In addition, the circuit board 207 itself may have a function of a support by forming the circuit board 207 so as to partially protrude.

The sub passage groove 250 forms a sub passage 234 in cooperation with the cover 202. The sub passage 234 is provided to extend along the projecting direction (longitudinal direction) of the measurement unit. The auxiliary passage groove 250 forming the auxiliary passage 234 has a first auxiliary passage groove 251 and a second auxiliary passage groove 252 branched in the middle of the first auxiliary passage groove 251. The first sub passage groove 251 is between the inlet 231 opened to the stepped surface 228 of the measuring unit 213 and the first outlet 232 opened on the other side of the measuring unit 213 and at a position facing the stepped surface 228. It is formed to extend along the short direction of the measuring unit 213. The inlet 231 is opposed to the upstream side in the flow direction of the measured gas 2 in the main passage 22. The first sub passage groove 251 takes in the gas to be measured 2 flowing in the main passage 22 from the inlet 231, and constitutes the first sub passage returning the taken in measured gas 2 from the first outlet 232 to the main passage 22. The first sub-passage extends from the inlet 231 along the flow direction of the gas to be measured 2 in the main passage 22 and leads to the first outlet 232.

The second sub passage groove 252 branches at an intermediate position of the first sub passage groove 251 and extends along the longitudinal direction of the measuring portion 213 toward the base end side (flange side) of the measuring portion 213. Then, it bends toward the other side in the short direction of the measurement unit 213 at the base end of the measurement unit 213, makes a U-turn, and extends along the longitudinal direction of the measurement unit 213 toward the tip of the measurement unit 213 again. . Then, it is bent toward the other side of the measurement unit 213 in the short side before the first outlet 232 and is provided so as to be continuous with the second outlet 233 opened on the other side surface 224 of the measurement unit 213 . The second outlet 233 is disposed to face the downstream side in the flow direction of the measurement target gas 2 in the main passage 22. The second outlet 233 has an opening area substantially equal to or slightly larger than that of the first outlet 232, and is formed at a position closer to the proximal end side in the longitudinal direction of the measuring portion 213 than the first outlet 232.

The second sub-passage groove 252 constitutes a second sub-passage for passing the measurement gas 2 branched from the first sub-passage and flowing in and returning it to the main passageway 22 from the second outlet 233. The second sub passage has a path that reciprocates along the longitudinal direction of the measurement unit 213. That is, the second sub passage branches off in the middle of the first sub passage, extends toward the proximal end side of the measuring unit 213, and is folded back at the proximal end side of the measuring unit 213. The second outlet 233 extends toward the tip end side and is disposed downstream of the inlet 231 in the flow direction of the measurement gas 2 in the main passage 22 in the flow direction downstream of the measurement gas 2. It has a connecting route. The flow rate sensor 205 is disposed at an intermediate position of the second sub passage groove 252. The second sub passage groove 252 can secure a longer passage length of the second sub passage, and can reduce the influence on the flow rate sensor 205 when pulsation occurs in the main passage.

According to the above configuration, the sub passage 234 can be formed along the extending direction of the measuring unit 213, and the length of the sub passage 234 can be secured sufficiently long. Thereby, the physical quantity detection device 20 can be provided with the sub-passage 234 with a sufficient length. Therefore, the physical quantity detection device 20 can measure the physical quantity of the gas to be measured 30 with high accuracy while suppressing the fluid resistance to a small value.

Since the first sub passage groove 251 extends from the inlet 231 to the first outlet 232 along the short direction of the measuring unit 213, dust etc. which has entered the first sub passage from the inlet 231 Foreign matter can be discharged from the first outlet 232 as it is, and foreign matter can be prevented from intruding into the second sub-passage, and influence on the flow rate sensor 205 in the second sub-passage can be prevented.

The inlet 231 and the first outlet 232 of the first sub passage groove 251 have an opening area larger at the inlet 231 than at the first outlet 232. By making the opening area of the inlet 231 larger than that of the first outlet 232, the gas to be measured 2 which has flowed into the first sub-passage can be reliably led to the second sub-passage branched in the middle of the first sub-passage. be able to.

A projection 253 is provided at the central position in the longitudinal direction of the inlet 231 of the first sub passage groove 251. The projecting portion 253 divides the size of the inlet 231 into two in the longitudinal direction, and makes the opening area smaller than that of the first outlet 232 and the second outlet 233. The protrusion 253 restricts the size of foreign matter that can enter the first sub-passage from the inlet 231 to only those smaller than the first outlet 232 and the second outlet 233, and the first outlet 232 and the second outlet 233 by foreign matter. Can be prevented from being blocked.

<Position of each sensor>
As shown in FIG. 6A, the circuit chamber 235 is provided on one side in the lateral direction of the measurement unit 213, and the circuit board 207 is accommodated. The circuit board 207 has a rectangular shape extending along the longitudinal direction of the measurement unit, and the chip package 208, the pressure sensor 204, and the humidity sensor 206 are mounted on the surface thereof.

The chip package 208 is mounted on the circuit board 207. In the chip package 208, the flow sensor 205 and an LSI, which is an electronic component for driving the flow sensor 205, are sealed by transfer molding. The flow rate sensor 205 and the LSI may be integrally formed on the same semiconductor element, or may be formed as separate semiconductor elements. The resin is sealed so that the flow rate measuring unit of the flow rate sensor 205 is at least exposed. Although the structure in which the LSI is provided in the chip package 208 has been described, a structure in which the LSI is mounted on the circuit board 207 may be employed. An advantage of providing the LSI in the chip package 208 is that it is not necessary to mount the LSI on the circuit board 207, which contributes to the miniaturization of the circuit board 207.

The chip package 208 has a shape that gradually squeezes from the side end to the flow rate sensor 207. This throttle shape rectifies the fluid flowing through the sub passage to reduce the noise influence. In addition to the throttle in the paper surface direction (surface direction of the chip package), if the throttle shape is also formed in the paper vertical direction by tilting in the paper surface vertical direction (thickness direction of the chip package), the fluid can be accelerated more. preferable. An advantage of the chip package 208 is that the diaphragm can be formed integrally with the flow sensor 205, so that the diaphragm can be formed with high accuracy relative to the flow sensor 205. As the dimensional accuracy error becomes severe with the miniaturization, the aperture can be formed with high accuracy, so it is possible to improve the flow rate detection accuracy.

In the chip package 208, a part of the chip package 208 protrudes to the other side in the short direction from the circuit board 207 at the longitudinal center position of the circuit board 207 so that the flow rate sensor 205 is disposed in the second sub passage groove 252. Is implemented in the state.

It is more preferable that the front end side of the circuit package is disposed in the sub-passage so that fluid flows to both the front side and the back side which are the measurement unit side. This is because the amount of dust reaching the front side on which the measurement unit is formed can be reduced by flowing the fluid also on the back side.

The pressure sensor 204 is mounted on the proximal end side in the longitudinal direction of the circuit board 207 with respect to the chip package 208, and the humidity sensor 206 is mounted on the distal end side in the longitudinal direction of the circuit board 207 than the chip package 208. The lead of the intake air temperature sensor 203 is connected to the surface of the circuit board 207. In the intake air temperature sensor 203, the lead 203b is connected to a position on the front end side of the circuit board 207 in the longitudinal direction than the humidity sensor 206, and the sensor main body 203a protrudes from the circuit board 207 in the longitudinal direction and is exposed to the outside of the measuring unit 213 It is implemented to be placed in.

In the measuring unit 213, (1) the pressure sensor 204, (2) the flow rate sensor 205, (in the direction in which the measuring unit 213 protrudes) from the proximal end side toward the distal end side along the longitudinal direction. 3) Humidity sensor 206, (4) Intake air temperature sensor 203 are arranged in order. In other words, the pressure sensor 204, the flow sensor 205, the humidity sensor 206, the intake air temperature sensor 203, and the circuit board 207 are arranged in order from the flange side.
(1) The pressure sensor 204 detects the pressure of the gas to be measured 2, and the flow rate sensor 205 detects the flow rate of the gas to be measured 2. The humidity sensor 206 detects the humidity of the gas to be measured 2, and the intake air temperature sensor detects the temperature of the gas to be measured.

FIG. 7A is an example of a numerical value graph showing a temperature influence range which is permitted to secure measurement accuracy of each sensor. The graph ranges from −25 ° C. (that is, 0 ° C.) to + 50 ° C. (that is, 75 ° C.) with respect to the reference temperature 25 ° C.

According to the numerical graph of FIG. 7A, (1) the pressure sensor 204 has a temperature influence tolerance range between −25 ° C. and 50 ° C., which is the widest among the respective sensors and the heat influence is small. Then, (2) the flow rate sensor 205 has a wide allowable range on the high temperature side, and the thermal influence on the high temperature side is small. On the other hand, (3) the humidity sensor 206 has a wide allowable range on the low temperature side, and the thermal influence on the low temperature side is small. Then, (4) the intake temperature sensor 203 is only in the vicinity where the tolerance range includes the reference temperature 25 ° C., the tolerance range of the temperature influence is the narrowest among the respective sensors, and the heat influence is large.

The difference in the temperature influence range shown in FIG. 7A is largely the difference in the detection principle of each sensor. For example, the pressure sensor with the widest tolerance range is a semiconductor type, and a strain gauge is formed on the surface of the diaphragm, and the external resistance changes the electrical resistance due to the piezoresistive effect generated by the external pressure. Are converted into electrical signals. The measurement error due to the temperature effect is mainly caused by the temperature dependency of the piezoresistor, but the linearity is relatively good and the measurement error can be suppressed by the temperature compensation. On the other hand, for the temperature sensor with the narrowest tolerance, the temperature is measured by heat transfer with the gas 2 to be measured, and if a thermal effect from a heat conducting member such as a substrate occurs, it causes a temperature error. Therefore, the allowable range basically becomes narrow.

The physical quantity detection device 20 is disposed, for example, in an engine room of a car. The temperature in the engine room is 60 ° C. to 100 ° C., and the temperature of the measured gas 2 passing through the main passage 22 is 25 ° C. on average. Therefore, the heat in the engine room is transmitted from the flange 211 side to the physical quantity detection device 20, and the temperature distribution thereof gradually decreases as it moves from the flange 211 side to the tip end side of the measurement unit 213 .

Therefore, in the measurement unit 213 of the present embodiment, the heat influence is the smallest (1) the pressure sensor 204 is disposed on the base end side which is the flange side, and then the heat influence is small on the high temperature side (2) (1) The pressure sensor 204 is disposed closer to the tip of the measurement unit 213 than the pressure sensor 204 is. Then, the heat effect is smaller at the next lower temperature side (3) The humidity sensor 206 is disposed closer to the tip of the measuring unit 213 than the flow rate sensor 205 (2) and most susceptible to heat (4) intake temperature The sensor 203 is disposed at the tip of the measuring unit 213. FIG. 7B is a graph showing the temperature change of each sensor in the engine room. As shown to FIG. 7B, it has temperature distribution according to arrangement | positioning order of each sensor.

According to the present embodiment, since the circuit board 207 is arranged to extend along the longitudinal direction of the measurement unit 213, the heat conduction distance from the flange 211 can be secured to the vicinity of the central axis of the main passage 22. And since each sensor of (1)-(4) is arranged in order of small thermal influence from the base end part of the measurement part 213 toward the tip part, even when mounting space is limited by miniaturization, Sensor performance of each sensor can be secured. In addition, by disposing the circuit board 207 on one side in the lateral direction of the measurement unit 213, heat transfer to the air can be promoted.

<Seal structure in circuit room>
8A is a front view of the housing with the cover removed, FIG. 8B is a front view of the circuit board 207, and FIG. 8C is a sectional view taken along line VIIIC-VIIIC of FIG. 8B.

As shown in FIGS. 8A to 8E, the hot melt adhesive 209 is applied to the circuit board 207 to protect the conductive portion between the circuit board 207 and each sensor. The sensor surface of each sensor is exposed without being covered by the hot melt adhesive 209 and the sensing function is not lost. The hot melt adhesive 209 is made of, for example, a resiliently deformable thermoplastic resin material, and is applied to the circuit board 207 in a heat-softened state.

The circuit chamber is adhered to the cover by adhesive at a portion shown by hatching in FIG. 8A, and the front side of the circuit board 207 is airtightly partitioned into three rooms R1, R2 and R3 by the adhesive and the hot melt adhesive 209 It is supposed to be. Specifically, a first chamber R1 in which the connector terminal 214 integrally formed in the housing 201 and the connection terminal portion of the circuit board 207 are connected, and a second chamber in which a part of the pressure sensor 204 and the chip package 208 are accommodated. A chamber R2 and a third chamber R3 in which the humidity sensor 206 is accommodated and the lead 203b of the intake air temperature sensor 203 is inserted are formed.

The first chamber R <b> 1 is sealed on the front side by the cover 202, and is a sealed space isolated from the outside of the measurement unit 213. Therefore, the connection portion between the connector terminal 214 and the connection terminal can be prevented from being in contact with the gas contained in the measurement gas 2 and corroded.

The second chamber R <b> 2 communicates with the second sub passage groove 252 via a gap between the second chamber R <b> 2 and the cover 202, and the pressure sensor 204 can measure the pressure. Further, by arranging the vent hole 274 of the ventilation passage for preventing the sealing of the diaphragm back surface of the flow rate sensor 205 formed in the chip package 208, the diaphragm back surface can be opened.

The third chamber R3 communicates with the outside of the measuring unit 213 through the lead insertion hole 216 for the intake air temperature sensor opened on the lower surface 226 of the measuring unit 213, and the humidity sensor 206 can measure the humidity. There is. Since the lead insertion hole 216 serving as a communication path for introducing the measurement medium to the humidity sensor 206 is formed at the position where the fluid is separated by the side surface 223 on one side, the intrusion of water droplets and dust as contamination is prevented. The measurement object can be introduced into the measurement unit R3.
In addition, although illustrated about the structure which divides 2nd chamber R2 and 3rd chamber R3, it is good also as the same space, without dividing.

<Structure of a single housing>
9A is a front view of the housing with the cover and the substrate removed, FIG. 9B is a cross-sectional view taken along line IXB-IXB of FIG. 9A, and FIG. 9C is a cross-sectional view taken along line IXC-IXC of FIG.

The housing 201 is provided with a rib 237 on the bottom of the circuit chamber 235 as shown in FIG. 9A. The rib 237 has a plurality of longitudinal ribs extending along the longitudinal direction of the measuring portion and a plurality of lateral ribs extending along the short direction of the measuring portion 213, and is provided in a grid shape There is.

The housing 201 can obtain high rigidity without increasing the thickness by providing the rib 237 in the measuring unit 213. The thickness of the housing 201 is largely different between the flange 211 and the measuring portion 213, the difference in thermal contraction rate after injection molding is large, and the measuring portion 213 having a smaller thickness than the flange 211 is easily deformed. Therefore, by providing the grid-like rib 237 extending in a planar manner on the bottom of the circuit chamber 235, distortion of the measurement portion 213 at the time of thermal contraction can be suppressed.

The housing 201 is provided with a rib 237 not on the outer wall of the measuring unit 213 but on the bottom surface (inside the housing) of the circuit chamber 235. When the rib 237 is provided on the outer wall of the measurement unit 213, the flow of the measurement gas 2 passing through the main passage 22 may be affected. Further, for example, in the case where the depth of the circuit chamber 235 is set on the premise that the circuit board 207 mounted on one side is accommodated, the circuit is changed when the specification is changed to accommodate the circuit board 207 mounted on both sides. Although it is necessary to increase the depth of the chamber 235, if the outer wall of the measuring unit 213 is provided with a rib, the rib protrudes by an amount corresponding to the increased depth of the circuit chamber 235, and the thickness of the measuring unit 213 is large. Become. Accordingly, the thickness of the measurement unit 213 is different between the single-sided mounting and the double-sided mounting, which may affect the detection accuracy.

On the other hand, in the present embodiment, since the rib 237 is provided on the bottom surface of the circuit chamber 235, the flow of the measurement gas 2 passing through the main passage 22 is prevented from being affected, and the measurement gas 2 is made smooth. It can flow. Then, the depth of the bottom of the circuit chamber 235 can be changed simply by changing the height of the rib 237 in the circuit chamber 235, and the thickness of the measurement portion is regardless of whether the circuit board 207 is single-sided mounting or double-sided mounting There is no need to change.

A connector terminal 214 is integrally formed on the housing 201. A proximal end of the connector terminal 214 is connected to an external terminal in the connector 212, and a distal end thereof is provided so as to protrude into the circuit chamber 235. As shown in FIG. 9C, the connector terminal 214 has a terminal (needle eye) whose end can be elastically deformed in the width direction, and by arranging the circuit board 207 in the circuit chamber 235, the end portion is a circuit board It has a press fit structure in which the electrical connection is made by press-fitting into the through hole 261 of 207.

A groove 238 for positioning and supporting the circuit board 207 is recessed in the bottom of the circuit chamber 235. The circuit board 207 is provided with projections 209 a at corresponding positions. The convex portion 209 a is configured by causing a part of the hot melt adhesive 209 to protrude. The circuit board 207 is in a state in which the transmission of vibration from the housing 201 is suppressed by fitting the convex portion 209 a made of the hot melt adhesive 209 having elasticity capable of elastic deformation into the groove hole 238. In the circuit chamber 235.

<Structure of cover>
The cover 202 is formed of, for example, a conductive material made of metal such as aluminum alloy or stainless alloy, or a conductive material such as conductive resin. The cover 202 has a flat plate shape that covers the front of the measurement unit 213, and is fixed to the measurement unit 213 by an adhesive. The cover 202 covers the circuit chamber 235 of the measuring unit 213, and forms a sub passage by cooperation with the sub passage groove 250 of the measuring unit 213. The cover 202 is electrically connected to the ground by interposing a conductive intermediate member between the cover 202 and the circuit board 207 or the connector terminal 214, and the sub-passage wall surface has a charge removing function. It is possible to remove the charge of the charged particles and to prevent the contamination of the flow rate sensor 205 from being attached.

As the intermediate member, conductive rubber, conductive adhesive, silver paste, or solder is used. Also, the static elimination function can be achieved by directly contacting the cover 202 with the circuit board or the connector terminal 214 without using an intermediate member. In this case, the cover may be formed of a conductive resin in order to prevent generation of cuttings due to vibration.

<Structure of Circuit Board 207>
10A is a front view of a circuit board on which a chip package and a circuit component are mounted, FIG. 10B is a cross-sectional view taken along line XB-XB of FIG. 10A, and FIG. 10C is a cross-sectional view taken along line XC-XC of FIG. 11A is a view showing a substrate sheet on which a plurality of circuit boards shown in FIG. 10A are formed, FIG. 11B is an enlarged view of the XIB portion in FIG. 11A, and FIG. 11C is a XIC-XIC line in FIG. FIG. 12 is a cross-sectional view showing a substrate sheet on which a plurality of circuit boards of the comparative example are formed.

The circuit board 207 has a rectangular shape (a shape in which the aspect ratio in the vertical and horizontal dimensions is larger than 1) extending in the longitudinal direction of the measuring unit 213. At one longitudinal end of the circuit board 207, a through hole 261 into which the connector terminal 214 of the housing 201 is press-fitted is provided. And, at a position adjacent to the through hole 261, a mounting point of the pressure sensor 204 is provided. One pressure sensor 204 may be provided as shown in FIG. 10A, or a plurality of pressure sensors may be arranged side by side.

The chip package 208 is fixed at the longitudinal center position of the circuit board 207. The chip package 208 is mounted so that a part thereof protrudes from the end of the circuit board 207. Specifically, the chip package 208 has its base end fixed at a position shifted to one side in the lateral direction at the center position in the longitudinal direction of the circuit board 207 and protrudes from the circuit board 207 along the lateral direction. The tip is located at the position. A flow sensor 205 is provided at the tip of the chip package 208 and is disposed in the second sub passage groove 252. The circuit board 207 is a position on the substrate surface of the circuit board 207 and deviated in the direction opposite to the projecting direction of the chip package 208 with respect to the chip package 208, a margin area S equal to or larger than the width of the chip package 208. have. The blank area S is provided on the other side of the chip package 208 in the lateral direction, and no circuit component is disposed and the substrate surface is exposed. The blank area S is an area having circuit wiring but no circuit component mounted.

In this embodiment, as shown in FIG. 11A, by mounting the chip package 208 on the circuit board 207, the entire chip package 208 fits on the surface of the circuit board 207 as in the comparative example shown in FIG. The size of the circuit board 207 can be reduced as compared to the case of mounting. In the case of the comparative example shown in FIG. 12, since the portion surrounded by the broken line B of the circuit board 207 is disposed in the sub passage, mounting of parts is impossible, which is a waste space. On the other hand, in the circuit board 207 of the present embodiment, the oversized part can omit about 30% of the size from the comparative example, and the circuit board 207 can be miniaturized.

Further, since the blank area S is provided in the area on the other side of the circuit board 207 in the width direction other than the chip package 208, as shown in FIG. 11A, the chip package 208 is formed on each circuit board 207 on the substrate sheet K. When mounting a chip, the tip of the chip package 208 protruding from the circuit board 207 can be placed on the margin area S of the other adjacent circuit board 207. That is, in the case of mounting the chip package 208 on the circuit board 207 in the state of the substrate sheet K, the blank area S has such a size that the protruding portion of the chip package mounted on another adjacent circuit board can be mounted. Have. Therefore, as compared with the comparative example in which the entire chip package 208 is mounted on the surface of the circuit board 207 as in the comparative example shown in FIG. The number of circuit boards 207 can be increased, and the productivity can be increased.
As a circuit board, a printed circuit board and a ceramic board are mentioned as an example.

As shown in FIG. 10A, the intake air temperature sensor 203 is disposed so as to protrude along the longitudinal direction from the short side of the circuit board 207. At the front end side of the circuit board 207, through holes 262 through which the pair of leads 203b of the intake air temperature sensor 203 are respectively inserted are provided. Each end of the pair of leads 203 b of the intake air temperature sensor 203 is inserted into the through hole 262, is bent along the surface of the circuit board 207, and protrudes from the short side of the circuit board 207. . Solder pads 263 are provided on the substrate surface of the circuit board 207 facing the pair of leads 203b, and the pads 263 and leads 203b are soldered. The sensor main body 203a is supported at a position separated from the circuit board 207 by a predetermined distance.

As shown in FIG. 11A, when the intake air temperature sensor 203 is mounted on each circuit board 207 on the substrate sheet K, the tips of the pair of leads 203b are inserted into the through holes 262, and each lead 203b is a circuit board It is arranged along the substrate surface of 207. Then, as shown in FIGS. 11B and 11C, the sensor main body 203a is disposed so as to enter the positioning hole K2 provided in advance in the frame K1 of the substrate sheet K. Therefore, the intake air temperature sensor 203 can be positioned at the correct position with respect to the circuit board 207 at the correct position, soldered in a stably supported state, and the mounting error with respect to the circuit board 207 can be reduced.

<Structure of Chip Package 208>
13A is a front view of the chip package, FIG. 13B is a rear view of the chip package, FIG. 13C is a left side view of the chip package, FIG. 13D is a right side view of the chip package, and FIG. FIG. 14 is a front view of a circuit board on which circuit components are not mounted.

The chip package 208 is configured by mounting the LSI and the flow rate sensor 205 on a metal lead frame and sealing it with a thermosetting resin. The flow rate sensor 205 and the LSI may be integrally formed of the same semiconductor element, or may be formed separately. The chip package 208 has a package main body 271 resin-molded into a substantially flat plate shape. The package body 271 has a rectangular shape, and extends along the short direction of the measuring unit 213, and the base end of the package body 271 on the one side in the longitudinal direction is disposed in the circuit chamber 235. The distal end side on the other longitudinal direction side is disposed in the second sub passage groove 252.

A plurality of connection terminals 272 are provided on the proximal end side of the package main body 271 so as to project therefrom. The chip package 208 is fixed to the circuit board 207 by soldering the plurality of connection terminals 272 to the pads 264 of the circuit board 207.

A flow rate sensor 205 is provided at the tip of the package body 271. The flow rate sensor 205 is disposed exposed in the second sub passage. The flow rate sensor 205 is provided in a passage groove 273 recessed in the surface of the package body 271. The passage groove 273 extends from the one end in the width direction along the width direction of the package body 271 so as to extend along the second sub passage groove 252 in the second sub passage groove 252. It is formed over the entire width to the other end.

Further, the passage groove 273 may be formed so as to narrow the portion where the flow rate sensor 205 is mounted. This is because the response can be improved by accelerating the flow.

The flow rate sensor 205 has a diaphragm structure, and a closed space chamber is formed on the back surface side of the package body 271 on the diaphragm side. The space chamber is connected to a ventilation port 274 opened on the surface of the proximal end of the package body 271 via a ventilation passage formed inside the package body 271.

Positioning convexes 275 for positioning on the circuit board 207 are provided on the back surface of the base end portion of the package body 271. The positioning convex portions 275 are provided in pairs at positions separated in the lateral direction of the package body 271. The circuit board 207 is provided with a positioning hole 265 into which the positioning convex portion 275 of the package body 271 is inserted. The chip package 208 can perform positioning with respect to the circuit board 207 by inserting the positioning convex portion 275 of the package body 271 into the positioning hole 265 of the circuit board 207.

Further, on the back surface of the package body 271, a projection 276 is provided to determine the posture of the package body 271 with respect to the circuit board 207 when the chip package 208 is attached to the circuit board 207 of the substrate sheet K. As shown in FIG. 13B, the protrusions are provided at the four corners of the base end and at the center in the short direction of the tip.

Protrusions 276 on the base end side contact the substrate surface of circuit board 207 to support package body 271 on circuit board 207, and projections 276 on the tip side are adjacent as shown in FIG. 11A. It is supported above the blank area S of the other circuit board 207. The protrusion 276 has a hemispherical shape, and can point-contact with the unevenness and inclination of the substrate surface of the circuit board 207 to appropriately support the package body 271.

In the chip package 208, the base end of the package body 271 is disposed on the circuit board 207 and the tip end of the package body 271 is disposed at a position projecting laterally from the circuit board 207, so the balance is bad. The part side may fall to the back side of the circuit board 207, and the base end side may tilt so as to be lifted from the surface of the circuit board 207.

In the present embodiment, a protrusion 276 is provided on the back surface of the package body 271 so that the front end and the base end of the package body 271 are respectively on both the circuit board 207 and another adjacent circuit board 207. Since it is placed on and supported, the package body 271 can be prevented from tilting. Therefore, by soldering the connection terminals 272 to the pads 264 of the circuit board 207, the chip package 208 can be fixed to the circuit board 207 in the correct attitude.

As mentioned above, although the embodiment of the present invention was explained in full detail, the present invention is not limited to the above-mentioned embodiment, and various designs are possible in the range which does not deviate from the spirit of the present invention described in the claim. It is possible to make changes. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the described configurations. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, with respect to a part of the configuration of each embodiment, it is possible to add / delete / replace other configurations.

1 Internal combustion engine control system
2 Measured gas
20 Physical quantity detection device
22 main passage
201 Housing
202 cover
203 Intake air temperature sensor
204 pressure sensor
205 Flow sensor
206 Humidity sensor
207 Circuit board
208 chip package
209 Hot melt adhesive
211 flange
212 connector
213 Measurement unit
214 connector terminal
215 rib (bottom of circuit chamber)
221 front
222 back
223 Side of one side
224 Side of the other side
226 Lower side of one side
227 Lower side of the other side
228 step surface
231 entrance
232 Exit 1
233 second exit
234 side passage
235 circuit room
237 rib (bottom of circuit chamber)
238 Grooves for Positioning (slots)
241 fixed hole
242 through holes
243 first rib
244 second rib
245 third rib
246 fourth rib
247 External terminal
248 Correction terminal
250 side passage ditch
251 first sub passage groove
252 second sub passage groove
253 projection
261 Through hole (for press fit)
262 Through hole (for lead)
263 pad (for intake air temperature sensor)
264 pad (for chip package terminal)
265 Positioning hole
271 Package body
272 connection terminal
273 Passage groove
274 Ventilation openings
275 Positioning projection
276 protrusion

Claims (7)

1. A flow rate measuring device comprising an intake air temperature sensor and a flow rate sensor,
   A secondary passage in which a flow sensor is disposed and takes in part of the fluid flowing in the main passage;
   And a wall portion provided upstream of the inlet of the sub-passage to generate flow separation.
   The flow rate measuring device, wherein the intake air temperature sensor is provided on the downstream side of the wall portion and on the upstream side of the inlet opening of the sub passage.
2. The flow rate measuring apparatus according to claim 1, wherein the intake air temperature sensor is disposed on the tip end side of the middle of the entrance opening projection surface of the auxiliary passage.
3. The flow rate measuring apparatus according to claim 1, wherein the intake air temperature sensor is disposed on an entrance aperture projection plane of the sub passage.
4. It has a circuit room in which a circuit board is mounted,
   The flow rate measuring apparatus according to claim 1, wherein the wall portion is also a wall portion forming the circuit chamber.
5. The flow rate measuring apparatus according to claim 4, wherein the lead of the intake air temperature sensor is mounted on the circuit board.
6. At least one of a humidity sensor and a pressure sensor is mounted on the circuit board,
   A ventilation passage is formed using a gap between the lead and the second wall of the circuit chamber on which the circuit board is mounted,
   The flow rate measuring device according to claim 5, wherein the second wall portion is located downstream of the wall portion.
7. The flow rate measuring device according to any one of claims 1 to 5, further comprising a protector for protecting the intake air temperature sensor.

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