Flow rate measuring device
The present disclosure provides a flow rate measuring device including a first chip, a second chip, and a holding body. The first chip and the second chip are disposed in an intake passage of an internal combustion engine. The first and second chips detect at least one of a flow rate of an intake air and a parameter other than the flow rate. The holding body holds the second chip and protrudes into an inside of the intake passage. The second chip is exposed inside of the intake passage in a state where the second chip is covered by a filter. The holding body includes a resin portion that forms a surface of the holding body. The portion of the filter is inserted into the resin portion. The recessed portion is recessed from a surface of the resin portion. A portion of a first surface of the filter defines a bottom of the recessed portion. The second chip is positioned on a side of a second surface of the filter that is opposite to the first surface.
1. A flow rate measuring device comprising:
a first chip and a second chip that are disposed in an intake passage of an internal combustion engine, the first and second chips detecting at least one of a flow rate of an intake air and a parameter other than the flow rate; and
a holding body that holds the second chip and protrudes into an inside of the intake passage, wherein
the second chip is exposed inside of the intake passage in a state where the second chip is covered by a filter,
the holding body includes a resin portion that forms a surface of the holding body, a portion of the filter being inserted into the resin portion,
a recessed portion is recessed from a surface of the resin portion, a portion of a first surface of the filter defining a bottom of the recessed portion, and
the second chip is positioned on a side of a second surface of the filter that is opposite to the first surface.
2. The flow rate measuring device according to claim 1 , further comprising
a main holder that holds the first chip, wherein
the main holder is away from the holding body and protrudes into the inside of the intake passage.
3. A method for manufacturing the flow rate measuring device according to claim 1 , the method comprising:
a molding step of forming the holding body by inserting the second chip, the filter, and a molten resin into a mold, wherein
the mold includes a protrusion to form the recessed portion,
the molding step includes inserting the molten resin into the mold in a state where the second chip is covered by the filter and a tip of the protrusion abuts against the first surface of the filter in the mold.
4. The method for manufacturing the flow rate measuring device according to claim 3 , wherein
the molding step includes:
inserting a high hardness component harder than the filter into the mold,
mounting the second chip on the high hardness component in the mold, and
covering the second chip mounted on the high hardness component with the filter.
5. The method for manufacturing the flow rate measuring device according to claim 3 , the method further comprising:
molding a pre-molded component in advance by resin-molding such that the second chip is exposed on a surface of the pre-molded component, wherein
the molding step includes inserting the second chip into the mold by inserting the pre-molded component into the mold.
6. The method for manufacturing the flow rate measuring device according to claim 5 , wherein
the molding step further includes:
inserting a high hardness component harder that the filter into the mold,
mounting the pre-molded component on the high hardness component, and
covering the pre-molded component mounted on the high hardness component with the filter.