JP2009287508A - Cooling water circulation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling water circulation system which does not hinder cooling performance. <P>SOLUTION: If an outside air temperature is not higher than a preset temperature, a first exhaust heat recovery circuit C1 is selected as a circulation circuit, in which a cooling water whose temperature is raised by heat recovered from exhaust gas of an engine E using an exhaust heat recovery unit 5 is flown into the engine E via a hydraulic oil heat exchanger 6 and is circulated. Meanwhile, if the outside air temperature is higher than the preset temperature, a second exhaust heat recovery circuit C2 is selected as the circulation circuit, in which the cooling water whose temperature is raised by heat recovered from exhaust gas of the engine E using the exhaust heat recovery unit 5 is flown into the engine E, but not via the hydraulic oil heat exchanger 6, and is circulated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooling water circulation device applied to an automobile including an engine and a transmission that operates in a state infiltrated with hydraulic oil.

  Generally, in order to avoid friction loss in the transmission at the time of engine cold start, it is important that the hydraulic fluid of the transmission is at least out of the cold state as soon as possible after engine start. Yes.

  Therefore, Patent Document 1 proposes a technique for more effectively reducing the friction loss of the transmission at the time of engine cold start.

Specifically, Patent Document 1 discloses that exhaust heat is recovered depending on whether the hydraulic oil temperature in the transmission has risen above a temperature that is lower than the hydraulic oil temperature in the hydraulic oil storage tank by a predetermined temperature difference. It is disclosed to determine whether to supply the heated hydraulic fluid to the transmission or to bypass the transmission.
JP 2004-176877 A

  By the way, in the cooling water circulation device of an automobile provided with an engine and a transmission that operates in a state infiltrated with hydraulic oil, when there is a hydraulic oil heat exchanger on the downstream side of the exhaust collector, for example, When the outside air temperature is low, such as in winter, the fuel economy and heater performance can be improved by warming up the transmission.For example, when the outside air temperature is high, such as in summer, the exhaust heat is reduced. Since the recovered hot cooling water flows into the hydraulic oil heat exchanger, the cooling performance is contradictory.

  Therefore, when the outside air temperature is lower than the set temperature, the heat oil heat exchanger is warmed. When the outside air temperature is higher than the set temperature, the exhaust heat recovery unit is used to actively cool the heat oil heat exchanger. It is necessary to switch the circulation circuit of the cooling water whose temperature is increased by the heat recovered from the exhaust gas.

  However, in the technique described in Patent Document 1, the fact is that no consideration is given to the above matters.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cooling water circulation device that does not contradict the cooling performance.

  In order to achieve the above object, a cooling water circulation device according to the present invention is a cooling water circulation device applied to an automobile including an engine and a transmission that operates in a state infiltrated with hydraulic oil, A first exhaust heat recovery circuit for circulating the cooling water whose temperature has been increased by heat recovered from the exhaust gas of the engine with the recovery unit, and flowing into the engine via the hydraulic oil heat exchanger, and operation When the outside air temperature is equal to or lower than the first set temperature, there are two systems including a second exhaust heat recovery circuit for flowing into the engine and circulating without passing through the oil heat exchanger. Switching means for switching the circulation circuit so that when the one exhaust heat recovery circuit is selected and the outside air temperature is higher than the first set temperature, the second exhaust heat recovery circuit is selected as the circulation circuit; Including.

  In the above configuration, when the outside air temperature is equal to or lower than the first set temperature, a cooling water whose temperature is increased by heat recovered from the exhaust gas of the engine by the exhaust heat recovery device is used as a circulation circuit as a heat exchanger for hydraulic oil A first exhaust heat recovery circuit is selected that flows into and circulates through the engine. On the other hand, when the outside air temperature is higher than the first set temperature, cooling water whose temperature is increased by heat recovered from the exhaust gas of the engine by the exhaust heat recovery device is used as a circulation circuit, and a heat exchanger for hydraulic oil is used. A second exhaust heat recovery circuit is selected that flows into the engine and circulates it without going through it. Therefore, for example, in the winter season, the hydraulic oil heat exchanger can be warmed, and in the summer season, for example, hot cooling water from which exhaust heat has been recovered can be prevented from flowing into the hydraulic oil heat exchanger. The heat exchanger can be actively cooled.

  Further, the cooling water circulation device further includes a hydraulic oil cooling circuit for directing the cooling water flowing out from the engine to the hydraulic oil heat exchanger without passing through the exhaust heat recovery unit, and circulating the cooling water into the engine. When the outside air temperature is higher than the first set temperature and the water temperature in the engine reaches the second set temperature in consideration of the limit temperature of the hydraulic oil, the switching means serves as the second exhaust gas as a circulation circuit. Means for allowing the hydraulic fluid cooling circuit to be selected in addition to the heat recovery circuit.

  In the above configuration, when the outside air temperature is higher than the first set temperature and the water temperature in the engine reaches the second set temperature considering the limit temperature of the hydraulic oil, the second exhaust is used as a circulation circuit. In addition to the heat recovery circuit, a hydraulic oil cooling circuit is selected in which the cooling water flowing out from the engine is directly led to the hydraulic oil heat exchanger without passing through the exhaust heat recovery device, and flows into the engine for circulation. Therefore, for example, even when high load operation continues in summer, the hydraulic oil heat exchanger can be cooled more actively.

  According to the present invention, when the outside air temperature is high as in summer, the cooling water whose water temperature is increased by the heat recovered from the exhaust gas of the engine by the exhaust heat recovery unit so as to actively cool the heat exchanger for hydraulic oil. The circulation circuit can be switched. As a result, there is no contradiction to the cooling performance of the cooling water circulation device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Overall configuration>
FIG. 1 is a circuit diagram schematically showing a cooling water circulation system of a cooling water circulation apparatus according to an embodiment of the present invention.

  Referring to FIG. 1, the cooling water circulation device according to the present embodiment is applied to an automobile provided with engine E and a transmission (not shown) that operates in a state infiltrated with hydraulic oil. A radiator 1, a thermostat 2, a water pump 3, a heater core 4, a waste heat recovery device 5, a hydraulic oil heat exchanger 6, and these devices 1, 2, 3, 4, 5 and 6. Includes piping and hoses H1, H2, H3, H4, H5, H6, H7, H8, H9, H10. In addition, as the heat exchanger 6 for hydraulic fluid, CVT (Continuously Variable Transmission) warmer, ATF (Automatic Transmission Field) warmer, etc. are employ | adopted.

  Specifically, the lower tank 11 and the thermostat 2 of the radiator 1 are connected by a lower hose H1.

  The discharge port of the water pump 3 communicates with the water jacket of the engine E. In this water jacket, the coolant from the water pump 3 passes through the water jacket on the cylinder block side, is introduced into the water jacket on the cylinder head side, and is then taken out from the engine E by the take-out pipe H2.

  The take-out pipe H2 is branched to the radiator 1 side and the heater core 4 side. One of the take-out pipes H1 is connected to the heater core 4 via the first hose H3, and the other is connected to the upper tank 12 of the radiator 1 via the upper hose H4.

  The heater core 4 and the inflow side of the exhaust heat recovery device 5 are connected by a second hose H5.

  The outflow side of the exhaust heat recovery device 5 is connected to the A port of the four-way valve 7 via a third hose H6. On the other hand, the inflow side of the hydraulic oil heat exchanger 6 is connected to the B port of the four-way valve 7 via a fourth hose H7.

  The outflow side of the hydraulic oil heat exchanger 6 and the suction side of the water pump 3 are connected by a fifth hose H8.

  Further, a sixth hose H9 that bypasses the hydraulic oil heat exchanger 6 is interposed between the C port of the four-way valve 7 and the middle portion of the fifth hose H8. In addition, a seventh hose H10 that bypasses the heater core 4 and the exhaust heat recovery device 5 is interposed between the D port of the four-way valve 7 and the middle portion of the first hose H3. A two-way valve 8 is provided in the middle of the seventh hose H10.

  In other words, the present cooling water circulation device has the first hose H3, the second hose H5, and the third hose with respect to the circulation of the cooling water whose water temperature is increased by the heat recovered from the exhaust gas of the engine E by the exhaust heat recovery device 5. H6, a fourth hose H7, and a fifth hose H8, a first exhaust heat recovery circuit C1 for flowing into the engine E through the heat exchanger 6 for hydraulic oil and circulating, 1 hose H3, 2nd hose H5, 3rd hose H6, 6th hose H9 and 5th hose H8, which flows into engine E without going through hydraulic oil heat exchanger 6 And a second exhaust heat recovery circuit C2 for circulation. Furthermore, in this cooling water circulation device, it is composed of the first hose H3, the seventh hose H10 and the fifth hose H8, and the cooling water flowing out from the engine E is not passed through the exhaust heat recovery device 5. A hydraulic fluid cooling circuit C3 is provided for directing the hydraulic fluid to the hydraulic fluid heat exchanger 6 so as to flow into the engine E for circulation.

<Configuration of exhaust heat recovery unit 5>
FIG. 2 is a longitudinal sectional view showing the internal structure of the exhaust heat recovery device 5 and cut along the flow direction of the exhaust gas. FIG. 3 is a cross-sectional view at a position corresponding to the line III-III in FIG.

  Referring to FIGS. 2 and 3, the exhaust heat recovery unit 5 is a substantially cylindrical member, and includes an exhaust heat recovery unit 5A disposed on the outer peripheral side of the exhaust heat recovery unit 5A and an exhaust heat recovery unit 5A. It is provided with a silencer 5B disposed on the peripheral side, and these are integrally formed.

  Specifically, the exhaust heat recovery device 5 has a substantially triple-pipe structure including three members, an outer cylinder member 51, an intermediate cylinder member 52, and an inner cylinder member 53. And in the space between the outer cylinder member 51 and the intermediate cylinder member 52, the said exhaust heat recovery part 5A is comprised, and the said silencer part 5B is comprised by the inner cylinder member 53. As shown in FIG.

  In the outer cylinder member 51, the central portion in the exhaust gas flow direction is a main body 51a having a relatively large diameter cylindrical shape, while both end portions in the exhaust gas flow direction are connected to the exhaust pipe 7 respectively. The side connection pipe part 51b and the discharge side connection pipe part 51c are formed. That is, the exhaust gas discharged from the engine E and flowing through the exhaust pipe 7 is introduced into the exhaust heat recovery unit 5 from the introduction side connection pipe portion 51b, and after passing through the exhaust heat recovery operation and the silencing operation, the exhaust side connection pipe The gas is discharged from the portion 51c toward the downstream side of the exhaust pipe 7.

  The intermediate cylinder member 52 is a cylindrical member, and an exhaust heat recovery space (gas flow path) 54 is formed between the outer peripheral surface thereof and the inner peripheral surface of the main body 51 a of the outer cylinder member 51. The intermediate tube member 52 is wound with a spiral pipe 55 having one end connected to the second hose H5 and the other end connected to the third hose H6. Both ends of the spiral pipe 55 pass through the main body 51 a of the outer cylinder member 51 and are disposed in the exhaust heat recovery space 54, and within the exhaust heat recovery space 54, the main body of the outer cylinder member 51. It is arrange | positioned so that a predetermined space | interval may exist between the internal peripheral surfaces of the part 51a. In other words, the outer diameter of the spiral pipe 55 is set slightly smaller than the height of the exhaust heat recovery space 54. For this reason, when the exhaust gas flows through the exhaust heat recovery section 5A, the exhaust gas flowing in the space (exhaust heat recovery space 54) on the outer peripheral side (the inner peripheral surface side of the outer cylinder member 51) than the spiral pipe 55 Heat exchange is performed with the cooling water flowing inside the spiral pipe 55, the heat of the exhaust gas is given to the cooling water, the temperature of the exhaust gas is lowered, and the temperature of the cooling water is raised. The spiral pipe 55 is disposed from one end to the other end of the intermediate cylinder member 52 in the exhaust gas flow direction. The flow direction of the cooling water in the intermediate pipe member 52 is the exhaust gas of the exhaust heat recovery unit 5. The second hose H5 and the third hose H6 are connected so that the introduction side is the cooling water inlet side and the exhaust gas discharge side of the exhaust heat recovery unit 5 is the cooling water outlet side.

  The inner cylinder member 53 is formed by a cylinder attached to the inner peripheral surface of the intermediate cylinder member 52, and a small cross-section passage portion 56 and a large cross-section passage portion 57 are sequentially formed from the upstream side in the exhaust gas flow direction. The small cross-section passage portion 56 has an inner passage cross-sectional area slightly smaller than the passage cross-sectional area of the exhaust pipe 7, and its axial length is about ¼ of the total length of the inner cylinder member 53. Is set to The upstream end of the small cross-section passage portion 56 in the exhaust gas flow direction is formed as the exhaust gas inlet 56a of the silencer 5B. On the other hand, the large cross-section passage portion 57 has an inner passage cross-sectional area larger in diameter than the passage cross-sectional area of the small cross-section passage portion 56 and the passage cross-sectional area of the exhaust pipe 7. It is set to about 3/4 of the total length of the cylindrical member 53. The downstream end of the large cross-section passage portion 57 in the exhaust gas flow direction is formed as an exhaust gas outlet 57a of the silencer 5B. Since the small cross-section passage portion 56 and the large cross-section passage portion 57 are formed in this way, a step A is formed at the boundary portion between the small cross-section passage portion 56 and the large cross-section passage portion 57, and the small cross-section passage portion is formed. The flow path is extended from the portion 56 to the large cross-sectional passage portion 57.

  The large cross-section passage portion 57 is provided with an on-off valve 58 that can open and close the exhaust gas outlet 57a. The on-off valve 58 has a disk shape that substantially matches the opening shape of the exhaust gas outlet 57a, and is supported by a rotating shaft 58a attached to the upper end portion of the inner peripheral surface of the intermediate cylinder member 52 to be a horizontal axis. The exhaust gas outlet 57a can be opened and closed by rotating around. Further, a spring is wound around the rotating shaft 58a, and the urging force of the spring in the direction of closing the exhaust gas outlet 57a is applied to the on-off valve 58 by the urging force of the spring. Therefore, in a state where the exhaust gas outlet 57a is closed by the on-off valve 58, the inner space of the inner cylinder member 53 is a space where only one side (upstream side in the exhaust gas flow direction) is opened. In the state where the exhaust gas outlet 57a is opened, the internal space of the inner cylinder member 53 is a space opened on both the upstream side and the downstream side.

<Electrical configuration>
FIG. 4 is a block diagram showing an electrical configuration of the cooling water circulation device.

  Referring to FIG. 4, the cooling water circulation device includes an ECU (Electronic Control Unit) 100. The ECU 100 serves as a control center of the cooling water circulation device, and includes a CPU, a ROM, a RAM, and the like. The ECU 100 is provided with detection signals from the outside air temperature sensor 101 and the water temperature sensor 102. Based on these detection signals, the ECU 100 controls the four-way valve 7 and the two-way valve 8 described above.

  The water temperature sensor 102 is a sensor for detecting the water temperature in the engine E, and faces the water jacket of the engine E as shown in FIG.

<Operation>
With reference to FIGS. 5-7, operation | movement of this cooling water circulation apparatus is demonstrated.

  If the ECU 100 determines that the outside air temperature is equal to or lower than the first set temperature TH1 (for example, 30 ° C.) based on the detection signal from the outside air temperature sensor 101, the ECU 100 opens the two-way valve 8 as shown in FIG. In addition, the first exhaust heat recovery circuit C1 is selected as a circulation circuit by communicating the AB port of the four-way valve 7. Then, the cooling water flows in the order of the first hose H3, the second hose H5, the third hose H6, the fourth hose H7, and the fifth hose H8. Therefore, the cooling water whose water temperature has been increased by the heat recovered from the exhaust gas of the engine E by the exhaust heat recovery device 5 flows into the engine E via the hydraulic oil heat exchanger 6, and the first exhaust heat recovery circuit Circulate C1.

  On the other hand, if the ECU 100 determines that the outside air temperature is higher than the first set temperature TH1 based on the detection signal from the outside air temperature sensor 101, the ECU 100 maintains the closed state of the two-way valve 8 as shown in FIG. The second exhaust heat recovery circuit C2 is selected as a circulation circuit by switching the communication port of the four-way valve 7 from the A-B port to the AC port while the state is kept. Then, the cooling water flows in the order of the first hose H3, the second hose H5, the third hose H6, the sixth hose H9, and the fifth hose H8. Therefore, the cooling water whose water temperature has been raised by the heat recovered from the exhaust gas of the engine E by the exhaust heat recovery device 5 flows into the engine E without passing through the hydraulic oil heat exchanger 6, and the second exhaust heat recovery Circuit C2 is circulated.

When the high load operation continues in the state shown in FIG. 6, the water temperature E _THW in the engine E rises. Therefore, when it is determined that the water temperature E _THW in the engine E has reached the second set temperature TH2 (for example, 125 ° C.) considering the limit temperature of the hydraulic oil based on the detection signal from the water temperature sensor 102, the ECU 100 The hydraulic oil cooling circuit C3 is selected in addition to the second exhaust heat recovery circuit C2 as a circulation circuit by opening the direction valve 8 and newly communicating with the BD port of the four-way valve 7. . Then, the cooling water flowing out from the engine E flows in the order of the first hose H3, the seventh hose H10, and the fifth hose H8. 6 is led directly into the engine E and circulates in the hydraulic oil cooling circuit C3.

<Action and effect>
According to the present embodiment, the following operations and effects are achieved.

  (1) When the outside air temperature is equal to or lower than the first set temperature TH1, as the circulation circuit, the cooling water whose temperature is raised by the heat recovered from the exhaust gas of the engine E by the exhaust heat recovery device 5 is used as the heat for hydraulic oil. A first exhaust heat recovery circuit C1 is selected that flows into the engine E through the exchanger 6 and circulates it. On the other hand, when the outside air temperature is higher than the first set temperature TH1, the cooling water whose temperature has been raised by the heat recovered from the exhaust gas of the engine E by the exhaust heat recovery device 5 is used as the hydraulic oil heat as a circulation circuit. A second exhaust heat recovery circuit C2 is selected that flows into the engine E and circulates it without passing through the exchanger 6. Therefore, for example, in the winter season, the hydraulic oil heat exchanger 6 can be warmed, and in the summer season, for example, hot cooling water from which exhaust heat has been recovered can be prevented from flowing into the hydraulic oil heat exchanger 6. The oil heat exchanger 6 can be actively cooled.

(2) When the outside air temperature is higher than the first set temperature TH1 and the water temperature E _THW in the engine E reaches the second set temperature TH2 (> TH1) considering the limit temperature of the hydraulic oil, circulation As a circuit, in addition to the second exhaust heat recovery circuit C2, the cooling water flowing out from the engine E is directly led to the hydraulic oil heat exchanger 6 without passing through the exhaust heat recovery unit 5 and flows into the engine E. The hydraulic oil cooling circuit C3 to be circulated is selected. Therefore, for example, even when a high load operation continues in summer, the hydraulic oil heat exchanger can be cooled more positively.

  As a result, the present cooling water circulation device does not contradict its cooling performance.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, an example in which the present invention is applied to a CVT vehicle or an AT vehicle has been described. However, the present invention is not limited to such a configuration. Even if the present invention is applied to a manual vehicle, the object of the present invention can be sufficiently achieved. It goes without saying that various design changes and modifications can be made within the scope of the claims attached to this specification.

It is a circuit diagram which simplifies and shows the circulating system of the cooling water of the cooling water circulating apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the internal structure of a waste heat recovery device, Comprising: (a) shows the closed state of an on-off valve, (b) shows the open state of an on-off valve. It is sectional drawing in the position corresponding to the III-III line in Fig.2 (a). It is a block diagram which shows the electrical structure of a cooling water circulation apparatus. It is a figure which shows a cooling water circulation path when outside temperature is below 1st preset temperature. It is a figure which shows a cooling water circulation path when outside temperature is more than 1st setting temperature. It is a figure which shows a cooling water circulation path | route when outside temperature is more than 1st preset temperature and the water temperature in an engine has reached 2nd preset temperature in consideration of the limit temperature of hydraulic oil.

Explanation of symbols

E Engine 5 Waste heat recovery device 6 Hydraulic oil heat exchanger 7 4-way valve 8 2-way valve 100 ECU
101 Outside air temperature sensor 102 Water temperature sensor H1-H10 Piping and hose

Claims (2)

A cooling water circulation device applied to an automobile including an engine and a transmission that operates in a state infiltrated with hydraulic oil,
A first exhaust heat recovery circuit for circulating the cooling water whose temperature has been increased by heat recovered from the exhaust gas of the engine by the exhaust heat recovery unit, and flowing into the engine via the hydraulic oil heat exchanger; , Having two systems with a second exhaust heat recovery circuit for flowing and circulating into the engine without going through the hydraulic oil heat exchanger,
When the outside air temperature is equal to or lower than the first set temperature, the first exhaust heat recovery circuit is selected as the circulation circuit, and when the outside air temperature is higher than the first set temperature, the second exhaust heat recovery is used as the circulation circuit. A cooling water circulation device comprising switching means for switching the circulation circuit so that the circuit is selected. The cooling water circulation device according to claim 1,
Further includes a hydraulic fluid cooling circuit for directing the coolant flowing out of the engine to the hydraulic fluid heat exchanger without passing through the exhaust heat recovery device and circulating the coolant through the engine;
When the outside air temperature is higher than the first set temperature and the water temperature in the engine reaches the second set temperature in consideration of the limit temperature of the hydraulic oil, the switching means serves as a circulation circuit to provide the second exhaust heat. A cooling water circulation device comprising means for selecting the hydraulic oil cooling circuit in addition to the recovery circuit.

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