Detection device for a physical quantity

Abstract

Detection device for a physical quantity (300), comprising: a housing (301) having a connection (303) and forming part of a through-passage (100); and a support body (600) which is configured to support a flow rate detection element (601), wherein the housing (301) has a neutralization area (500), wherein the carrier body (600) is arranged in the housing (301) such that a detection unit of the flow rate detection element (601) faces the neutralization area (500), and wherein in the housing (301) a contact section with the carrier body (600) and a surface of the neutralization area (500) are essentially flush.

Description

Technical field

[0001] The invention relates to a detection device for a physical quantity for the intake air of an internal combustion engine. State of the art

[0002] PTL 1 discloses a structure of a detection device for a physical quantity in which a neutralization area is provided in a passage through which a target gas flows to remove a charge of a pollutant as a countermeasure against contamination in order to prevent pollutants from adhering to a flow rate detection unit.

[0003] DE 11 2016 004 977 T5 describes a flow meter comprising an assembly that includes a conduit and a circuit component installed on the conduit, wherein a section of the conduit is encapsulated with resin. The assembly is provided with an exposed section that is electrically connected to a conductor forming part of a path, with a section of the conduit exposed within the resin material. DE 11 2017 001 166 T5 discloses a device for determining a physical quantity, in which the electrical connection is made to a conductor that is exposed at a point where a gas to be measured flows through it.JP 2017-207280 A presents a thermal flow meter characterized in that it includes a secondary channel for conveying gaseous material to be measured, which is taken from a main channel; a flow sensing element for detecting a flow rate is arranged within the secondary channel; a cover for forming the secondary channel is included, wherein the cover is formed by injection molding; a conductive element for detecting the flow rate is arranged within the secondary channel; and a cover for forming the secondary channel is included. DE 10 2014 225 303 A1 describes a sensor for determining at least one parameter of a fluid medium flowing through a measuring channel, which enables a reduction or prevention of dust contamination of the micromechanical sensor membrane, the sensor chip, and the sensor carrier, and thus a reduction of characteristic curve drift. Listed literature Patent literature

[0004] PTL 1: WO 2017 / 073271 A1 Summary of the invention: Technical problem

[0005] In the case of a structure where a metal plate, installed facing a flow rate detection element, is connected to a circuit housing, as shown in PTL 1, a neutralization area must maintain a constant potential and therefore must be connected to the ground (GND) of a printed circuit board (PCB) or similar component mounted on one side of the housing. This necessitates an electrical conductor running in the thickness direction between the PCB and the housing. An intermediate conductive element is required for this conductor structure, increasing the number of components. Furthermore, this connection must be implemented in a process distinct from the standard electrical connection process required for linking to the external device, resulting in increased costs.

[0006] The invention was made with regard to the above points and one object of the invention is to provide a detection device for a physical quantity which is able to connect electrically with a neutralization area which is arranged at a point through which a target gas flows, in a simple process. Solution to the task

[0007] A detection device according to the invention for a physical quantity comprises a housing having a connection and a passage through which a target gas flows, and a support body carrying a flow rate detection element. A neutralization zone is formed on a bottom surface of a passage in the housing, and the support body is carried by the housing such that a detection unit of the flow rate detection element faces the neutralization zone. A contact section with the support body and a surface of the neutralization zone are essentially flush within the housing. Advantageous effects of the invention

[0008] According to the invention, a neutralization function can be implemented in a simple process. Since the covering can be excluded from the components of the passage, it is also possible to reduce deviations in the dimensional tolerance of the passage of the flow rate detection element. Tasks, configurations, and effects, in addition to those described above, will become apparent from the discussion of the following embodiments. Brief description of the drawings Fig. Figure 1 is a front view of a detection device for a physical quantity. Fig. Figure 2 is a rear view of the detection device for a physical quantity. Fig. Figure 3 is a left side view of the detection device for a physical quantity. Fig. Figure 4 is a right side view of the detection device for a physical quantity. Fig. Figure 5 is a front view, representing a state in which a cover is removed from the detection device for a physical quantity. Fig. 6 is a cross-sectional view taken along line AA from Fig. 1 is taken from. Fig. Figure 7 is a front view showing another embodiment in which the cover is removed from the detection device for a physical quantity. Fig. Figure 8 is a cross-sectional view taken along line BB from Fig. 7 is taken from. Fig. Figure 9 is a cross-sectional view taken along line AA, which represents another embodiment of the detection device for a physical quantity. Fig. Figure 10 is a cross-sectional view taken along line AA, which represents another embodiment of the detection device for a physical quantity. Fig. Figure 11 is a cross-sectional view taken along line AA, which represents another embodiment of the detection device for a physical quantity. Fig. Figure 12 is an enlarged view of a neutralization area in Fig. 5. Fig. 13 is a cross-sectional view taken along line CC from Fig. 4 is taken from which another embodiment of the detection device for a physical quantity is shown. Description of embodiments (First embodiment)

[0009] Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows a representation illustrating the appearance of a detection device 300 of a physical quantity. Fig. Figure 1 is a front view of the detection device 300 of a physical quantity, Fig. 2 is a rear view, Fig. 3 is a left side view and Fig. 4 is a right-side view.

[0010] The physical quantity detection device 300 has a housing 301 and a cover 302. The housing 301 is formed by molding a synthetic resin material and has a flange 311 for attaching the physical quantity detection device 300 to the intake body, as well as an external connection section 321 projecting from the flange 311 and having a connector for electrical connection to an external device.

[0011] The housing 301 is provided with a circuit board 400 (see Fig. 5) The circuit board 400 is electrically connected to a detection element 601, which is supported by a carrier body 600. The detection element 601 is arranged in a passage 100 formed by the housing 301 and the cover 302, and a detection unit thereof is exposed to a target gas 30 flowing through the passage 100. Part of the carrier body 600 is arranged in the lower passage 100, and part of it is arranged in the circuit chamber.

[0012] The carrier body 600 can be a resin housing sealed with resin in such a way that at least the detection unit of the flow rate detection element 601 is exposed, or it can be a resin-molded body having a mounting section on which the flow rate detection element 601 is mounted.

[0013] The housing 301 is provided with a neutralization zone 500, which serves to eliminate static electricity from a pollutant traveling with the target gas 30. The neutralization zone 500 extends 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 carrier body 600 so that it faces the neutralization zone 500 and is installed in the housing 301 (see Fig. 6) The neutralization area 500 only needs to be grounded in the sense of a circuit; it is made of a conductive metal plate, a conductive resin or the like, and it is provided in the housing 301 by insertion, plating or the like.

[0014] The carrier body 600 is arranged in contact with the housing 301 on the side of the detection element 601, and the neutralization area 500 and the carrier body 600 form a detection passage section 101.

[0015] According to this embodiment, by arranging the carrier body 600, which carries the detection element 601 in the housing, such that it faces the side of the housing 301, the detection element 601 can be oriented towards the neutralization area 500 formed in the housing 301 on which the printed circuit board 400 is mounted. The neutralization area can be formed within the housing 301; a connection from the printed circuit board 400 to the cover 302 is not necessary, nor is a connection in the assembly and stacking direction required, and a neutralization function can be provided on the side of the detection element in a simple operation. In the same operation, a connection between a terminal 303 provided in the housing 301 and the printed circuit board 400, and a connection between the neutralization area 500 and a constant potential of the printed circuit board 400, can be established, thus simplifying the process.

[0016] Furthermore, by forming the detection passage section 101 of the detection element 601 through the housing 301, the cover 302 and the printed circuit board 400 can be excluded from the factors forming the detection passage section 101, and the dimensional deviations of the detection passage section 101 can be reduced and the detection accuracy can be improved, while the tolerance of the cover 302 and the tolerance of the printed circuit board 400 can be ignored.

[0017] By having the neutralization area 500 and the contact surface between the carrier body 600 and the housing 301 essentially flush, the dimensional tolerance of the housing in the height dimension tolerance of the detection passage section 101 can also be ignored, so that the dimensional deviation of the detection passage section 101 can be reduced and the detection accuracy improved, which is more preferred. (Second embodiment)

[0018] As in Fig. 7 and Fig. As illustrated in Figure 8, the carrier body 600 has a leadframe 610 which is electrically connected to terminal 303. The leadframe 610 is electrically connected to terminal 303 by welding or the like. Furthermore, the neutralization area 500 is electrically connected to terminal 303 by welding or the like via a leadframe 611. If a sensor, such as a pressure sensor or a humidity sensor, which is not a flow rate sensor, is not required when a circuit function is provided in the carrier body 600, the circuit board 400 becomes redundant, and the number of components and the cost can be reduced. Although not shown, the leadframe 610 can be connected to the neutralization area 500 and can also be connected to terminal 303. (Third embodiment)

[0019] As in Fig. As illustrated in Figure 9, the carrier body 600 is mounted on the printed circuit board 400. After the printed circuit board assembly has been formed, in which the carrier body 600 is mounted on the printed circuit board 400, the printed circuit board assembly is mounted on the housing 301. The carrier body 600 is mounted on the printed circuit board 400 such that the side of the detection element faces the side of a rear surface of the printed circuit board 400.

[0020] In the housing 301, a step 320 is formed such that a mounting section for the printed circuit board 400 is located outside a contact section with which the carrier body 600 is in contact. When the printed circuit board 400 is mounted on the housing 301 after the carrier body 600 has been mounted on the printed circuit board 400, the carrier body 600 can be brought into contact.

[0021] Since the distance between the detection element 601 and the neutralization area 500 can be made shorter than the thickness of the circuit board 400, by even providing the stage 320 without contact, it is also possible to increase the flow velocity, and the effect is that noise behavior is improved even in a structure in which the neutralization area is provided on the side of the housing and the detection element is arranged so that it faces the side of the housing.

[0022] When the side of the detection element 601 of the carrier body 600 is brought into contact with the housing 301, the height of the step 320 is preferably greater than the distance from the bottom surface of the printed circuit board 400 to the contact section in contact with the housing of the carrier body 600. Since deviations of the printed circuit board 400 can be accommodated by the adhesive provided between the printed circuit board 400 and the housing 301, the stress exerted on the connection section between the carrier body 600 and the printed circuit board 400 can be reduced. (Fourth embodiment)

[0023] As in Fig. As illustrated in Figure 10, the neutralization area can extend to the inner end of the step 320. In other words, the carrier body 600 is in contact with the housing 301 in the neutralization area 500. If the neutralization area 500 is provided in the housing 301 by insertion or plating, a step, albeit a tiny one, is formed. Even if such a step is present, in the first embodiment it lies in the area of ​​substantially the same plane. However, since the contact section and the section forming the measuring passage 101 are formed in the same neutralization area, the flatness is further improved. (Fifth embodiment)

[0024] As in Fig. As illustrated in Figure 11, the neutralization zone 500 extends to the lower section of the printed circuit board 400. Since the neutralization zone 500 is formed, for example, from a metal plate, the rigidity of the housing 301 can be improved, as can its vibration resistance. Furthermore, because the metal plate is located below the printed circuit board 400, the significant difference in the coefficient of linear expansion between the printed circuit board 400 and the housing 301 is reduced, thus minimizing deformation of the printed circuit board 400 and reducing stress and strain on the electronic component mounted on the printed circuit board 400. (Sixth embodiment)

[0025] As in Fig. As illustrated in Figure 12, the neutralization area 500 is installed in parallel to the connection 303.

[0026] Furthermore, the neutralization area 500 is installed on the base side (flange side) of the terminal 303 with respect to the terminal end face 304. In this embodiment, since the neutralization area 500 is parallel to the terminal 303, the feasibility of an electrical connection can be improved. Moreover, the neutralization area 500 is formed, for example, from a metal plate and arranged on the base side of the terminal 303, thus improving the rigidity of the housing 301 and enhancing its vibration resistance. (Seventh embodiment)

[0027] As in Fig.As illustrated in Figure 13, the neutralization zone 500 is located on the base side of the connection 303 and extends to the inside of the flange 311. The neutralization zone 500 is, for example, formed from a metal plate and extends to the inside of the flange, thus improving the rigidity of the housing 301 and enhancing its vibration resistance.

[0028] The embodiments of the invention have been described up to this point; however, the invention is not limited to these embodiments. Various modifications can be made within a certain scope, provided they do not depart from the concept of the invention disclosed in the claims. For example, the embodiments of the invention described above have been described in detail and in a clearly understandable manner, and they are not limited to those embodiments that exhibit all of the described features. Furthermore, some features of a particular embodiment can be replaced by features of other embodiments, and features of other embodiments can be added to the features of the embodiment in question.Furthermore, some of the features of each embodiment can be omitted, replaced with other features, and added to other embodiments. Reference symbol list 30 Target gas 100 Passage section 101 Detection passage section 300 Detection device for a physical quantity 301 Housing 302 Cover 303 connection 304 Connection end surface 311 Flange 320 stepped section 400 printed circuit boards 500 neutralization range 600 carrier bodies 601 Detection element 610, 611 Ladder frame

Claims

[1] Detection device for a physical quantity (300), comprising: a housing (301) having a connection (303) and forming part of a through-passage (100); and a support body (600) which is configured to support a flow rate detection element (601), wherein the housing (301) has a neutralization area (500), wherein the carrier body (600) is arranged in the housing (301) such that a detection unit of the flow rate detection element (601) faces the neutralization area (500), and wherein in the housing (301) a contact section with the carrier body (600) and a surface of the neutralization area (500) are essentially flush. [2] Detection device for a physical quantity (300) according to claim 1, wherein the neutralization area (500) is formed from a metal plate. [3] Detection device for a physical quantity (300) according to claim 1, wherein the neutralization area (500) is made of a conductive resin. [4] Detection device for a physical quantity (300) according to claim 1, wherein the carrier body (600) has a conductor frame (610, 611), wherein the conductor frame (610, 611) is connected to the connection (303) and the neutralization area (500) is connected to the connection (303). [5] Detection device for a physical quantity (300) according to claim 1, wherein the carrier body (600) has a conductor frame (610, 611), the conductor frame (610, 611) is connected to a printed circuit board (400), the neutralization area (500) is connected to the printed circuit board (400) and the printed circuit board (400) is connected to the terminal (303). [6] Detection device for a physical quantity (300) according to claim 1, wherein the neutralization area (500) is provided parallel to the connection (303) and the neutralization area (500) is arranged closer to a root side of the connection (303) than to an end face (304) of the connection (303). [7] Detection device for a physical quantity (300) according to claim 1, comprising a printed circuit board (400) on which the carrier body (600) is mounted, wherein the circuit board (400) is mounted on the housing (301), and the housing has a step (320) at which the mounting section of the printed circuit board (400) is located outside a contact section with the carrier body (600). [8] Detection device for a physical quantity (300) according to claim 7, wherein a height of the step is greater (320) than a distance from a bottom surface of the circuit board (400) to a contact section in contact with a housing of the carrier body (600). [9] Detection device for a physical quantity according to claim 1, wherein the neutralization area (500) extends to a lower section of the printed circuit board (400).

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