Heating resistor type flow measuring device

Abstract

A heating resistor type flow measuring device comprising a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage, a flow rate detection element held on the frame body side of the housing, and an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector, wherein the electronic circuit is held on the frame body side of the housing and positioned in the fluid passage, a member with the rigidity higher than the material of the main structural member of the housing is formed integrally with the support part, the housing is fixed to the fluid passage through the member with high rigidity. A metal plate is inserted into the support part so as to increase rigidity. Further, a distance is provided between the support part and a metal plate forming a route for conducting the heat transferred to the metal base fixing an electronic circuit substrate by a plastic mold so as to form a structure obstructing a heat transfer, or a clearance is provided in a portion spaced by the plastic mold between the support part and the metal base so as to form a structure obstructing a heat transfer.

1 . A heating resistor type flow measuring device comprising: 
 a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage,    a flow rate detection element held on the frame body side of the housing, and    an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector,    wherein    the electronic circuit is held on the inside of the frame body of the housing and positioned in the fluid passage,    a member with the rigidity higher than the material of the main structural member of the housing is formed integrally with the support part, the housing is fixed to the fluid passage through the member with high rigidity.    
   
   
       2 . A heating resistor type flow measuring device according to  claim 1 , wherein the material of the main structural member of said housing is plastic, and said material with high rigidity is a metal plate.  
   
   
       3 . A heating resistor type flow measuring device according to  claim 2 , wherein plastics are arranged on both sides of said metal plate in said support part, and at least one part of said metal plate is covered with said plastics.  
   
   
       4 . A heating resistor type flow measuring device according to  claim 2 , wherein said support is composed of each layer of plastic, metal plate, plastic in order from the side near said fluid passage, and the thickness of said layers are 1.0-2.0 mm, 1.0-2.5 mm, and 1.0 mm-5.0 mm, respectively.  
   
   
       5 . A heating resistor type flow measuring device according to  claim 2 , wherein said housing frame has a metal base on which said electronic circuit is fixed, and an insulated layer is provided between the metal base and said metal plates in said support part.  
   
   
       6 . A heating resistor type flow measuring device according to  claim 2 , further comprising: 
 said metal plate having a metal base with a smooth side where said electronic circuit is fixed, which is integrated with said support part, and    an insulated layer of which the width substantially corresponds to the section in said housing frame body, and between said metal bases,    wherein said sub-intake air passage and the circuit are inserted from the rectangular hole provided to the fluid passage structural member which forms the intake air passage, and said support part is fixed.    
   
   
       7 . A heating resistor type flow measuring device according to  claim 2 , further comprising: 
 a cover to protect the interior of said electronic circuit,    wherein the interval of a plastic molding from said metal plate integrated with said support part to the bonding ditch of said cover is 5 mm-20 mm.    
   
   
       8 . A heating resistor type flow measuring device according to  claim 1 , wherein said connector terminal to connect electrically to the external equipment which penetrates through said frame body has a part where the width is thinned in the plastic thick wall part provided to said frame of said housing.  
   
   
       9 . A heating resistor type flow measuring device according to  claim 2 , wherein the interval of a plastic molding from said metal plate, which composes, said support part to said metal base in said frame body part is 5 mm-20 mm.  
   
   
       10 . A heating resistor type flow measuring device according to  claim 2 , wherein the interval from the rectangular hole provided to said fluid passage structural member which forms said intake air passage to said metal base is 0.5 mm-1.0 mm.  
   
   
       11 . A heating resistor type flow measuring device according to  claim 2 , wherein a clearance is provided within the distance of a plastic molding from said metal plate which composes said support part to said metal base.  
   
   
       12 . A heating resistor type flow measuring device according to  claim 2 , wherein the seal member is installed in the space between said support part and said fluid passage structural member, said sealant is prevented dropping out in the clearance of the plastic molding between said support part and said metal base, and an insulated layer is formed with the plastic molding having the thin wall part and said seal material.  
   
   
       13 . A heating resistor type flow measuring device comprising: 
 a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage,    a flow rate detection element held on the frame body side of the housing, and    an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector,    wherein    the electronic circuit is held on the inside of the frame body of the housing and positioned in the fluid passage, and    a part of the connector terminal provided in said connector is extended to the frame body part to reinforce the frame body of said housing.    
   
   
       14 . A heating resistor type flow measuring device comprising: 
 a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage,    a flow rate detection element held on the frame body side of the housing, and    an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector,    wherein    the electronic circuit is held on the inside of the frame body of the housing and positioned in the fluid passage, and    a part of the metal plate formed integrally with said support part is bent and inserted into the frame body of said housing.    
   
   
       15 . A heating resistor type flow measuring device comprising: 
 a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage,    a flow rate detection element held on the frame body side of the housing, and    an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector,    wherein    the electronic circuit is held on the inside of the frame body of the housing and positioned in the fluid passage, and    said connector terminal to connect electrically to the external equipment provided through the frame body has a part where width was thinned in a plastic thick wall part provided in the frame body of said housing.    
   
   
       16 . A heating resistor type flow measuring device according to  claim 1 , wherein the temperature sensitive resistor or the intake temperature sensor to measurer the intake temperature or the both are fixed to the detection element support terminal, as well as flow rate detection element connected electrically to said electronic circuit electric and fixed to said housing, including said heating resistor.  
   
   
       17 . A heating resistor type flow measuring device according to  claim 16 , wherein said detection element support terminal which connects said intake temperature sensor and connecter terminal to the controller of the internal combustion engine are connected through the conductor provided in said electronic circuit.  
   
   
       18 . A heating resistor type flow measuring device according to  claim 17 , wherein the thermal conductivity of the material of said detection element support terminal that connects said intake temperature sensor is lower compared with that of said connecter terminal.  
   
   
       19 . A heating resistor type flow measuring device according to  claim 1 , wherein the sub-intake air passage where said flow rate detection element is built in is provided to the frame body of said housing, and said temperature sensitive resistor and said intake temperature sensor are arranged in the vicinity of the upstream entrance in said sub-intake air passage.  
   
   
       20 . A heating resistor type flow measuring device according to  claim 1 , wherein the transistor for current amplification is provided in said electronic circuit, and said transistor for current amplification is arranged at the relatively remote position from said temperature sensitive resistor and said intake temperature sensor.  
   
   
       21 . A heating resistor type flow measuring device according to  claim 1 , further comprising a dropout prevention mechanism for said metal base provided to said frame body of said housing.  
   
   
       22 . An internal combustion engine for a vehicle comprising a heating resistor type flow measuring according to  claim 1.