Heat exchanger and duplex type heat exchanger

Abstract

A heat exchanger has first and second header tanks, multiple built-up tubes connected between the header tanks. A communication pipe is also connected between the header tanks. A separator is provided in the first header tank, so that a tank space of the first header tank is divided into first and second sub-tank spaces. The first sub-tank space is communicated with the multiple built-up tubes, whereas the second sub-tank space is communicated with the communication pipe. An inlet pipe is connected to the second sub-tank space and fluidically connected to an automatic transmission through a vehicle delivery pipe, wherein a flow path sectional area of the communication pipe is almost equal to that of the delivery pipe.

1 . A heat exchanger comprising: 
 a pair of first and second header tanks;    an inlet pipe and an outlet pipe provided to one of the header tanks, the inlet and outlet pipes being connected to a heat generating device through delivery pipes so that working fluid is supplied from the heat generating device to the header tank to which the inlet and outlet pipes are provided and the working fluid returns to the heat generating device from the same header tank;    a first group of multiple built-up tubes, both longitudinal ends of which are respectively connected to the header tanks, so that the working fluid flows from one of the header tanks to the other header tank through the multiple built-up tubes;    a communication pipe connected between the header tanks so that tank spaces formed in the respective header tanks are fluidically communicated with each other through the communication pipe, the communication pipe being arranged at an outer side of the built-up tubes in a direction of building-up the tubes, the communication pipe having a flow path sectional area almost equal to that of the delivery pipes;    a separator provided in the header tank to which the inlet and outlet pipes are provided, for dividing the tank space formed by the header tank into first and second sub-tank spaces, so that the first sub-tank space is communicated with the tubes and the second sub-tank space is communicated with the communication pipe; and    a bypass flow path having a certain flow resistance and formed in the separator for communicating the first and second sub-tank spaces with each other,    wherein the inlet pipe is fluidically connected to one of the sub-tank spaces, whereas the outlet pipe is fluidically connected to the other sub-tank space, so that a certain amount of the working fluid directly flows from the sub-tank space connected with the inlet pipe to the other sub-tank space connected with the outlet pipe through the bypass flow path, and the remaining amount of the working fluid flows from the sub-tank space connected with the inlet pipe to the other sub-tank space connected with the outlet pipe through the communication pipe and the multiple tubes.    
   
   
       2 . A heat exchanger according to  claim 1 , wherein 
 a curved portion is provided at a middle portion of the communication pipe for absorbing thermal deformation in a longitudinal direction of the communication pipe.    
   
   
       3 . A heat exchanger according to  claim 1 , further comprising: 
 another heat exchanger which includes; and    another pair of third and fourth header tanks;    a second group of multiple built-up tubes, both longitudinal ends of which are respectively connected to the other pair of header tanks, so that another working fluid flows from one of the third and fourth header tanks to the other of the third and fourth header tanks through the second group of the multiple built-up tubes,    wherein the multiple tubes of the second group are continuously built-up in the same direction to that of the multiple tubes of the first group, and    wherein the third and fourth header tanks are integrally formed with the respective first and second header tanks.    
   
   
       4 . A heat exchanger according to  claim 3 , wherein 
 the multiple tubes of the second group have the same specifications to that of the multiple tubes of the first group.    
   
   
       5 . A heat exchanger according to  claim 3 , wherein 
 a dummy tube is disposed between the multiple tubes of the first group and the multiple tubes of the second group,    wherein the dummy tube is filled with air and no working fluid flows through the dummy tube.    
   
   
       6 . A heat exchanger according to  claim 5 , wherein 
 the dummy tube has the same specifications to that of the multiple tubes of the first and second groups.    
   
   
       7 . A heat exchanger according to  claim 3 , wherein 
 the heat exchanger is an oil-cooler for cooling the working fluid of an automatic transmission for a vehicle, and    the other heat exchanger is a condenser for cooling refrigerant of an air conditioning apparatus for the vehicle.    
   
   
       8 . A heat exchanger comprising: 
 a pair of first and second header tanks;    an inlet pipe provided to the second header tank;    an outlet pipe provided to the first header tanks, the inlet and outlet pipes being connected to a heat generating device through delivery pipes so that working fluid is supplied from the heat generating device to the second header tank and the working fluid returns to the heat generating device from the first header tank;    a first group of multiple built-up tubes, both longitudinal ends of which are respectively connected to the header tanks, so that the working fluid flows from the second header tank to the first header tank through the multiple built-up tubes;    a communication pipe connected between the header tanks so that tank spaces formed in the respective header tanks are fluidically communicated with each other through the communication pipe, the communication pipe being arranged at an outer side of the built-up tubes in a direction of building-up the tubes , the communication pipe having a flow path sectional area almost equal to that of the delivery pipes;    a separator provided in the first header tank, for dividing the tank space formed by the first header tank into first and second sub-tank spaces, so that the first sub-tank space is communicated with the tubes and the second sub-tank space is communicated with the communication pipe; and    a bypass flow path having a certain flow resistance and formed in the separator for communicating the first and second sub-tank spaces with each other,    wherein a certain amount of the working fluid flows from the tank space formed by the second header tank to the second sub-tank space of the first header tank through the communication pipe, whereas the remaining amount of the working fluid flows from the tank space formed by the second header tank to the first sub-tank space of the first header tank through the multiple tubes, and    wherein the working fluid flows from the second sub-tank space to the first sub-tank space though the bypass flow path and flows out of the first sub-tank space through the outlet pipe.    
   
   
       9 . A heat exchanger comprising: 
 a pair of first and second header tanks;    an inlet pipe provided to the second header tank;    an outlet pipe provided to the first header tanks, the inlet and outlet pipes being connected to a heat generating device through delivery pipes so that working fluid is supplied from the heat generating device to the second header tank and the working fluid returns to the heat generating device from the first header tank;    a first group of multiple built-up tubes, both longitudinal ends of which are respectively connected to the header tanks, so that the working fluid flows from the second header tank to the first header tank through the multiple built-up tubes;    a communication pipe connected between the header tanks so that tank spaces formed in the respective header tanks are fluidically communicated with each other through the communication pipe, the communication pipe being arranged at an outer side of the built-up tubes in a direction of building-up the tubes, the communication pipe having a flow path sectional area almost equal to that of the delivery pipes;    a separator provided in the second header tank, for dividing the tank space formed by the second header tank into first and second sub-tank spaces, so that the first sub-tank space is communicated with the tubes and the second sub-tank space is communicated with the communication pipe; and    a bypass flow path having a certain flow resistance and formed in the separator for communicating the first and second sub-tank spaces with each other,    wherein the inlet pipe is fluidically connected to the first sub-tank space, so that a certain amount of the working fluid directly flows from the first sub-tank space to the second sub-tank space through the bypass flow path, and then to the tank space formed by the first header tank through the communication pipe, and    wherein the remaining amount of the working fluid flows from the first sub-tank space to the tank space formed by the first header tank through the multiple tubes.    
   
   
       10 . A duplex type heat exchanger for a vehicle comprising: 
 a first heat exchanger having first and second header tanks and first multiple tubes, both longitudinal ends of the first multiple tubes being connected to the first and second header tanks so that tank spaces formed in the first and second header tanks are fluidically communicated with each other through the first multiple tubes;    a second heat exchanger having third and fourth header tanks and second multiple tubes, both longitudinal ends of the first multiple tubes being connected to the third and fourth header tanks so that tank spaces formed in the third and fourth header tanks are fluidically communicated with each other through the second multiple tubes, wherein the third header tank is integrally formed with the first header tank and the fourth header tank is integrally formed with the second header tank;    a communication pipe connected to the first and second header tanks, so that the tank spaces formed in the first and second header tanks are fluidically communicated with each other through the communication pipe;    a separator provided in the first header tank for separating the tank space formed in the first header tank into first and second sub-tank spaces, so that each one end of the first multiple tubes is communicated with the first sub-tank space and one end of the communication pipe is communicated with the second sub-tank space;    an inlet pipe provided to the first header tank to be fluidically communicated to the second sub-tank space, the inlet pipe being connected to an automotive parts device through a vehicle delivery pipe;    an outlet pipe provided to the first header tank to be fluidically communicated to the first sub-tank space, the outlet pipe being connected to the automotive parts device through the vehicle delivery pipe;    a bypass flow path formed in the separator, so that a portion of working fluid from the inlet pipe flows from the second sub-tank space to the tank space of the second header tank, whereas the remaining portion of the working fluid flows from the second sub-tank space to the first sub-tank space through the bypass flow path,    wherein a flow path sectional area of the communication pipe is almost equal to that of the vehicle delivery pipe.