Physical quantity detection device

Abstract

The present invention provides a physical quantity detection device that can achieve electrical connection with a static-eliminating area disposed in a place where a measured gas passes through by a simple process. The physical quantity detection device (300) of the present invention includes: a housing (301) having a terminal (303) and a channel portion (100) through which a measured gas passes; and a support body (600) that supports a flow detection element (601). A static-eliminating area (500) is formed on the bottom surface of the channel portion of the housing, and the support body is supported on the housing in a manner such that the detection portion of the flow detection element is opposite to the static-eliminating area.

Description

Technical Field

[0001] The present invention relates to a physical quantity detection device for intake air of an internal combustion engine. Background Art

[0002] Patent Document 1 discloses a physical quantity detection device that provides a static electricity removal area in a passage through which a gas to be measured flows, and removes the charge of contaminants, as a contamination countermeasure to prevent contaminants from adhering to a flow rate detection unit.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: PCT International Patent Application No. WO2017 / 073271 Summary of the invention

[0006] Problems to be solved by the invention

[0007] As shown in Patent Document 1, in the case of a structure in which a metal plate disposed opposite to a flow detection element is connected to a circuit package, the anti-static area needs to be at a constant potential, so it needs to be connected to the GND of a circuit board or the like mounted on the housing side. For this purpose, an electrical conduction structure in the thickness direction of the circuit board and the cover is required. An intermediate member having conductivity is required in the conduction structure, resulting in an increase in the number of components. In addition, this requires a process different from the process of electrical connection with the terminal required to obtain a connection with an external device, which results in an increase in cost.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a physical quantity detection device that can achieve electrical connection with a static electricity removal area disposed at a location where a measured gas passes through by a simple process.

[0009] Means of solving the problem

[0010] The physical quantity detection device of the present invention comprises a housing and a support body supporting a flow detection element, wherein the housing has a terminal and a channel portion through which a measured gas passes. A static-eliminating region is formed on the bottom surface of the channel portion of the housing, and the support body is supported on the housing in such a manner that a detection portion of the flow detection element faces the static-eliminating region.

[0011] Effects of the Invention

[0012] According to the present invention, the static electricity removal function can be realized by a simple process. In addition, since the cover can be removed from the constituent elements of the channel, the channel size tolerance deviation of the flow detection element can be reduced. In addition, the above-mentioned topics, structures and effects are clarified by the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the front view of the physical quantity detection device.

[0014] Figure 2 It is the rear view of the physical quantity detection device.

[0015] Figure 3 It is a left side view of the physical quantity detection device.

[0016] Figure 4 It is a right side view of the physical quantity detection device.

[0017] Figure 5 This is a front view showing a state where a cover is removed from the physical quantity detection device.

[0018] Figure 6 for Figure 1 AA cross-section diagram.

[0019] Figure 7 This is a front view showing another embodiment in which a cover is removed from the physical quantity detection device.

[0020] Figure 8 for Figure 7 BB cross-section diagram.

[0021] Fig. 9 It is an AA cross-sectional view showing another embodiment of the physical quantity detection device.

[0022] Fig.10 It is an AA cross-sectional view showing another embodiment of the physical quantity detection device.

[0023] Fig.11 It is an AA cross-sectional view showing another embodiment of the physical quantity detection device.

[0024] Fig.12 for Figure 5 Enlarged image of the static electricity removal area.

[0025] Fig.13 To show another embodiment of the physical quantity detection device Figure 4 CC cross-section diagram. DETAILED DESCRIPTION

[0026] Embodiment 1

[0027] Figure 1 to Figure 4 2 is a diagram showing the appearance of the physical quantity detection device 300. Figure 1 is a front view of the physical quantity detection device 300, Figure 2 is the rear view, Figure 3 The left side view. Figure 4 It is the right side view.

[0028] The physical quantity detection device 300 includes a housing 301 and a cover 302. The housing 301 is formed by molding a synthetic resin material, and has a flange 311 for fixing the physical quantity detection device 300 to the intake body and an external connection portion 321 protruding from the flange 311 and having a connector for electrically connecting to an external device.

[0029] The housing 301 is provided with a circuit board 400 (see Figure 5 ). The circuit board 400 is electrically connected to a detection element 601 supported by a support body 600. The detection element 601 is arranged in a channel 100 formed by a housing 301 and a cover 302, and its detection portion is exposed to the measured gas 30 flowing through the channel 100. A portion of the support body 600 is arranged in the sub-channel 100, and a portion is arranged in the circuit chamber.

[0030] The support body 600 may be a resin package sealed with resin so that at least the detection portion of the flow detection element 601 is exposed, or may be a resin molded body having a mounting portion for mounting the flow detection element 601 .

[0031] The housing 301 is provided with a static electricity removal area 500, which has the function of removing static electricity from contaminants that fly along with the measured gas 30. The static electricity removal area 500 is provided from the passage 100 to the circuit chamber and is electrically connected to the circuit board 400. The detection element 601 is supported by the support body 600 in a manner opposite to the static electricity removal area 500 and is provided on the housing 301 (see Figure 6 The static electricity removal area 500 only needs to be electrically grounded, and is composed of a conductive metal plate, a conductive resin, etc., and is provided on the housing 301 by means of an insert, electroplating, etc.

[0032] The support body 600 is arranged in contact with the housing 301 on the detection element 601 side, and the detection channel section 101 is constituted by the static electricity removal region 500 and the support body 600 .

[0033] According to this embodiment, the support body 600 supporting the detection element 601 is arranged on the housing in a manner facing the housing 301 side, thereby enabling the detection element 601 to be opposite to the static electricity removal area 500 formed on the housing 301 on which the circuit board 400 is mounted. The static electricity removal area can be formed on the housing 301, and there is no need for conduction from the circuit board 400 to the cover 302, and there is no need for conduction in the direction of the mounting stack, and the static electricity removal function can be set on the detection element side with a simple process. Moreover, the conduction between the terminal 303 provided on the housing 301 and the circuit board 400, and the conduction of the constant potential of the static electricity removal area 500 and the circuit board 400 can be implemented in the same process, and the process can also be simplified.

[0034] In addition, the detection channel portion 101 of the detection element 601 is formed by the shell 301, thereby the cover 302 and the circuit board 400 can be removed from the elements constituting the detection channel portion 101, the tolerance of the cover 302 and the tolerance of the circuit board 400 can be ignored, and the dimensional deviation of the detection channel portion 101 can be reduced accordingly, thereby improving the detection accuracy.

[0035] Furthermore, the contact surface between the static electricity removal area 500 and the support body 600 and the shell 301 is made to be roughly in the same plane, thereby being able to ignore the dimensional tolerance of the shell from the height dimensional tolerance of the detection channel part 101, thereby being able to reduce the dimensional deviation of the detection channel part 101 and improve the detection accuracy, which is therefore more preferred.

[0036] Embodiment 2

[0037] like Figure 7 , Figure 8 As shown, the support body 600 has a lead frame 610 electrically connected to the terminal 303. The lead frame 610 is electrically connected to the terminal 303 by welding or the like. Furthermore, the static electricity removal area 500 is electrically connected to the terminal 303 by welding or the like via the lead frame 611. In the case where a sensor other than a flow rate measurement sensor such as a pressure sensor or a humidity sensor is not required, if a circuit function is provided on the support body 600, the circuit board 400 is not required, and the number of components and the cost can be reduced. Although not shown in the figure, the lead frame 610 can also be connected to the static electricity removal area 500, and then connected to the terminal 303.

[0038] Embodiment 3

[0039] like Fig. 9 As shown, the support body 600 is mounted on the circuit board 400. After the circuit board assembly is formed by mounting the support body 600 on the circuit board 400, the circuit board assembly is mounted on the housing 301. The support body 600 is mounted on the circuit board 400 with the detection element side facing the back side of the circuit board 400.

[0040] The housing 301 has a step 320 formed outside the mounting portion of the circuit board 400 relative to the contact portion of the support body 600. After the support body 600 is mounted on the circuit board 400, when the circuit board 400 is mounted on the housing 301, the support body 600 can be brought into contact with the housing 301.

[0041] In addition, even without contact, by setting the step 320, the distance between the detection element 601 and the static electricity removal area 500 can be made shorter than the thickness of the circuit board 400, thereby increasing the flow rate. Even in a structure in which the static electricity removal area is set on the shell side and the detection element is configured to face the shell side, it has the effect of improving the noise performance.

[0042] When the detection element 601 side of the support body 600 is brought into contact with the housing 301, it is more preferable that the height of the step 320 is greater than the distance from the bottom surface of the circuit board 400 to the contact portion of the support body 600 that contacts the housing. The deviation of the circuit board 400 can be absorbed by the adhesive provided between the circuit board 400 and the housing 301, so the stress applied to the connection portion between the support body 600 and the circuit board 400 can be reduced.

[0043] Embodiment 4

[0044] like Fig.10 As shown, the static electricity removal area can also extend to the inner end of the step 320. In other words, the support body 600 contacts the housing 301 in the static electricity removal area 500. When the static electricity removal area 500 is set on the housing 301 by an inlay or electroplating process, a small step will be formed. Even if the step is included, it is included in the range of the roughly same plane in the first embodiment, but since the contact portion and the portion forming the measurement channel 101 are formed in the same static electricity removal area, the flatness is further improved.

[0045] Embodiment 5

[0046] like Fig.11 As shown, the anti-static area 500 is set to the lower part of the circuit board 400. The anti-static area 500 is formed of a metal plate, for example, so that the rigidity of the housing 301 can be improved and the vibration resistance can be improved. In addition, by setting the metal plate at the lower part of the circuit board 400, the difference in linear expansion coefficient between the outer surfaces of the circuit board 400 and the housing 301 becomes smaller, which can reduce the deformation of the circuit board 400 and reduce the stress and deformation of the electronic components mounted on the circuit board 400.

[0047] Embodiment 6

[0048] like Fig.12 As shown, the static electricity removal area 500 is arranged in parallel with the terminal 303.

[0049] Furthermore, the static electricity removal area 500 is arranged on the root side (flange side) of the terminal 303 relative to the terminal end face 304. In this embodiment, the static electricity removal area 500 is arranged in parallel with the terminal 303, thereby improving the workability of the electrical connection. In addition, the static electricity removal area 500 is formed of, for example, a metal plate and is arranged on the root side of the terminal 303, thereby improving the rigidity of the housing 301 and improving the vibration resistance.

[0050] Embodiment 7

[0051] like Fig.13 As shown, the static electricity removal area 500 is arranged at the root side of the terminal 303 and further arranged inside the flange 311. The static electricity removal area 500 is formed of a metal plate, for example, and arranged inside the flange, thereby improving the rigidity of the housing 301 and improving the vibration resistance.

[0052] The embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various design changes can be made within the scope of the purpose of the present invention as described in the claims. For example, the above embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to having all the structures described. In addition, a part of the structure of an embodiment can be replaced with the structure of other embodiments, and in addition, the structure of other embodiments can be added to the structure of one embodiment. Furthermore, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0053] Explanation of symbols

[0054] 30 Measured gas

[0055] 100 Channel Department

[0056] 101 Detection channel

[0057] 300 Physical quantity detection device

[0058] 301 Shell

[0059] 302 Cover

[0060] 303 terminal

[0061] 304 terminal end face

[0062] 311 Flange

[0063] 320 steps

[0064] 400 Circuit Board

[0065] 500 Anti-static Area

[0066] 600 Support

[0067] 601 Detection element

[0068] 610, 611 lead frame.

Claims

1. A physical quantity detection device, characterized in that: have: a housing having a terminal for connection with an external device and forming a part of the secondary passage; a cover forming another portion of the secondary channel; as well as a support body, which supports the flow detection element, The housing has a static electricity removal area. The support body is arranged on the housing in such a manner that a detection portion of the flow detection element faces the static electricity removal area, and the detection portion is provided on a side of the support body away from the cover.

2. The physical quantity detection device according to claim 1, characterized in that: The static electricity removal area is formed of a metal plate.

3. The physical quantity detection device according to claim 1, characterized in that: The static electricity removal area is made of a conductive resin.

4. The physical quantity detection device according to claim 1, characterized in that: The support body includes a lead frame, the lead frame is connected to the terminal, and the static electricity removal region is connected to the terminal.

5. The physical quantity detection device according to claim 1, characterized in that: The support body includes a lead frame, the lead frame is connected to a circuit board, the static electricity removal area is connected to the circuit board, and the circuit board is connected to the terminal.

6. The physical quantity detection device according to claim 1, characterized in that: The contact portion between the housing and the support body and the surface of the static electricity removal area are substantially flush with each other.

7. The physical quantity detection device according to claim 1, characterized in that: The static electricity removal area is provided in parallel with the terminal, and the static electricity removal area is arranged closer to the root side of the terminal than the end surface of the terminal.

8. The physical quantity detection device according to claim 1, characterized in that: A circuit board is provided for mounting the support body, The circuit board is mounted on the housing. The housing has a step, and the mounting portion of the circuit board is located outside a contact portion where the step contacts the support body.

9. The physical quantity detection device according to claim 8, characterized in that: The height of the step is greater than the distance from the bottom surface of the circuit board to the contact portion of the support body that contacts the housing.

10. The physical quantity detection device according to claim 1, characterized in that: The static electricity removal area is arranged to extend to the lower part of the circuit board.

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