JP2005214075A - Cooling device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine capable of prematurely warming up the internal combustion engine in low temperature starting by a simple structure. <P>SOLUTION: This cooling device is used for the internal combustion engine in which the downstream side end of a main circulating passage 16 having a radiator and the downstream side ends of a bypass passage 19 and a heater passage 21 bypassing the radiator are connected to a water jacket (water pump inlet passage 18) through a merged part 17. The cooling device comprises a heat sensitive actuator 31 disposed in the merged part 17 and deformed according to the temperature of a cooling water, a first valve 36 allowing the main circulating passage 16 and the water pump inlet passage 18 to communicate with each other or cut out from each other by opening and closing according to the deformation of the heat sensitive actuator 31, and a second valve 41 opened and closed according to the deformation of the heat sensitive actuator 31, allowing the bypass passage 19 and the water pump inlet passage 18 to communicate with each other or cut out from each other, and allowing the heater passage 21 and the water pump inlet passage 18 to communicate with each other or cut out from each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling apparatus for an internal combustion engine that circulates cooling water and cools the internal combustion engine by exchanging heat between the cooling water and the internal combustion engine.

  As a cooling device for an internal combustion engine mounted on a vehicle or the like, for example, the one described in Patent Document 1 can be cited. In this cooling device, as shown in FIG. 7, a water jacket 51 is formed inside the internal combustion engine, and a water pump (W / P) 52 is disposed in the vicinity of the inlet. The upstream end of the main circulation passage 54 having the radiator 53 is connected to the outlet of the water jacket 51, and the downstream end is connected to the water pump 52 via the switching valve 55 and the water pump inlet passage 56.

  The cooling device is provided with a first bypass passage 57 and a heater passage 58 that bypass the radiator 53 and a second bypass passage 59 that bypasses the water jacket 51. The upstream end of the first bypass passage 57 is connected between the radiator 53 and the outlet of the water jacket 51 in the main circulation passage 54, and the downstream end is connected to the switching valve 55. The upstream end of the heater passage 58 is connected to the outlet of the water jacket 51, and the downstream end is connected to the switching valve 55. The upstream end of the second bypass passage 59 is connected to the inlet of the water jacket 51, and the downstream end is connected to the switching valve 55.

  The switching valve 55 communicates and shuts off the water jacket 51 (water pump inlet passage 56) of each of the main circulation passage 54, the first bypass passage 57, the heater passage 58, and the second bypass passage 59 according to the operating state of the internal combustion engine. For switching. The switching valve 55 includes a cylindrical housing, a valve main body rotatably incorporated in the housing, a motor connected to a rotation shaft of the valve main body, and a controller. The controller controls energization of the motor based on signals from a sensor for detecting the starting state of the internal combustion engine, a sensor for detecting the temperature of the cooling water, and the like. Through this control, the valve body is rotationally driven by the motor, and the communication / blocking of the passages 54 and 57 to 59 with respect to the water pump inlet passage 56 is switched as follows.

  When the internal combustion engine is started at a low temperature, the switching valve 55 causes the second bypass passage 59 and the water pump inlet passage 56 to communicate with each other. Each of the main circulation passage 54, the first bypass passage 57, and the heater passage 58 is blocked from the water pump inlet passage 56. The cooling water only circulates through the water pump inlet passage 56 and the second bypass passage 59 and does not flow into the water jacket 51 as indicated by arrows in FIG. Cooling water does not flow through the heater passage 58. As described above, the flow of the cooling water in the water jacket 51 is restricted by blocking the flow of the cooling water in the main circulation passage 54, the first bypass passage 57, and the heater passage 58. As a result, heat generated by the combustion of the air-fuel mixture is confined in the internal combustion engine, and the intake port, the combustion chamber, etc. are preferentially warmed and the combustion state is improved early.

  Further, when the temperature of the cooling water is lower than the required value, each of the first bypass passage 57 and the heater passage 58 and the water pump inlet passage 56 are communicated by the switching valve 55. Each of the main circulation passage 54 and the second bypass passage 59 is blocked from the water pump inlet passage 56. Therefore, the cooling water flows around the radiator 53, and the overcooling of the cooling water is suppressed.

Further, when the temperature of the cooling water is equal to or higher than the required value, the main circulation passage 54 and the water pump inlet passage 56 are communicated by the switching valve 55. At this time, each of the first bypass passage 57 and the second bypass passage 59 is disconnected from the water pump inlet passage 56. As the cooling water flows through the radiator 53, the temperature of the cooling water is lowered.
Japanese Patent Laid-Open No. 11-280473 (pages 4, 5, 7 and FIG. 2)

  However, according to Patent Document 1 described above, when the internal combustion engine is started at a low temperature, it is possible to prevent the heat around the combustion chamber from diffusing and to achieve early warm-up. For this purpose, the second bypass passage 59 is provided. In addition, a motor for driving the valve main body is newly required, and energization control of the motor by the controller is also newly required. And these things invite complication of the whole system including the structure of a cooling device.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cooling device for an internal combustion engine that can warm up the internal combustion engine early at the time of low-temperature start with a simple configuration. It is in.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, an internal combustion engine in which a downstream end of a main circulation passage having a radiator, and a bypass passage that bypasses the radiator and each downstream end of a heat receiving / radiating passage are connected to an engine cooling water passage through a junction. A cooling device used in an engine, which is disposed in the merging portion and is deformed according to the temperature of the cooling water, and is opened and closed according to deformation of the thermal actuator, and the main circulation passage and the engine A first valve for communicating or blocking the cooling water passage, and opening and closing according to deformation of the thermal actuator, and communicating or blocking the bypass passage and the engine cooling water passage, and also the receiving and radiating passage and the engine cooling water passage And a second valve that communicates or shuts off.

  According to said structure, the cooling water which flows through each path | route of a main circulation path, a bypass path, and a heat-receiving / radiating path is guide | induced to an engine cooling water path, after passing a junction part. At the junction, the thermal actuator is deformed into a form corresponding to the temperature of the cooling water, and the first valve and the second valve are opened and closed accordingly. The main circulation passage and the engine coolant passage are communicated or blocked by opening and closing the first valve. Further, by opening and closing the second valve, the bypass passage and the engine cooling water passage are communicated or blocked, and the heat receiving / radiating passage and the engine cooling water passage are communicated or blocked. Therefore, by appropriately setting the relationship between the cooling water temperature and the opening and closing timings of the first and second valves in advance, the main circulation passage, the bypass passage, and the heat receiving and radiating heat when the temperature of the cooling water is low. Each of the passages and the engine coolant passage can be blocked. These interruptions confine the heat generated by the combustion of the air-fuel mixture when the internal combustion engine is started at a low temperature, preferentially warm up each part of the internal combustion engine, and suppress the diffusion of the heat to the heat receiving and radiating passage etc. It becomes possible.

  Further, the passages and the engine cooling water passages are blocked by the thermal actuator being deformed according to the temperature change of the cooling water. This eliminates the need for driving means such as a motor for driving the switching valve and control for operating the driving means. Thus, according to the first aspect of the present invention, the internal combustion engine can be warmed up early at the time of low-temperature start-up while having a simple configuration.

  According to a second aspect of the present invention, in the first aspect of the present invention, a first region in which the downstream end of the main circulation passage and the upstream end of the engine coolant passage are connected to each other in the merging portion, A partition wall is provided to partition the bypass passage and a second region to which each downstream end of the heat receiving and radiating passage is connected, and the first valve is connected to the connection portion of the main circulation passage in the first region and the second region. A first seat portion provided between a connection portion of the engine coolant passage and a first main body portion which is displaced in accordance with deformation of the thermal actuator and is seated on or separated from the first seat portion. Suppose there is.

  According to said structure, a 1st main-body part is displaced with a deformation | transformation of the thermosensitive actuator according to the change of the temperature of cooling water. When the first main body portion is seated on the first seat portion and the first valve is closed, the inflow of the cooling water from the main circulation passage to the engine cooling water passage is blocked. On the other hand, when the first main body portion is separated from the first seat portion and the first valve is opened, the main circulation passage and the engine cooling water passage are in communication with each other through the first region. Inflow from the circulation passage to the engine cooling water passage becomes possible.

  According to a third aspect of the present invention, in the second aspect of the present invention, the first main body portion is attached to the thermal actuator, and the first body portion is only when the temperature of the cooling water is lower than the first temperature. It is assumed that it is seated on one seat part.

  According to said structure, when the temperature of the cooling water in a confluence | merging part is less than 1st temperature, a 1st main-body part will seat on a 1st seat part, a 1st valve will close, and the main circulation passage of cooling water To the engine cooling water passage is blocked. On the other hand, when the temperature of the cooling water becomes equal to or higher than the first temperature, the first main body portion is separated from the first seat portion, the first valve is opened, and the cooling water main circulation passage to the engine cooling water passage Inflow becomes possible.

  According to a fourth aspect of the present invention, in the second or third aspect of the invention, the second valve is displaced with the deformation of the second seat portion provided on the partition wall and the thermal actuator. Suppose that the 2nd main-body part seated on the 2nd seat part or leaves | separates is provided.

  According to said structure, a 2nd main-body part is displaced with a deformation | transformation of the thermal actuator according to the change of the temperature of cooling water. When the second main body portion is seated on the second seat portion and the second valve is closed, the inflow of the coolant from the bypass passage and the heat receiving / radiating passage to the engine coolant passage is blocked. On the other hand, when the second main body portion is separated from the second seat portion and the second valve is opened, each of the bypass passage and the heat receiving / radiating passage and the engine coolant passage are communicated through the second region; Become. The cooling water can flow into the engine cooling water passage from each of the bypass passage and the heat receiving and radiating passage.

  The invention according to claim 5 is the invention according to claim 4, wherein the second main body is attached to the thermal actuator, and the temperature of the cooling water is set to be equal to or lower than the first temperature. It is assumed that the seating is performed on the second seat portion only when the temperature is less than two temperatures.

  According to said structure, when the temperature of the cooling water in a confluence | merging part is less than 2nd temperature, a 2nd main-body part seats on a 2nd seat part, a 2nd valve closes, a bypass passage of cooling water, and Inflow from the heat receiving / radiating passage to the engine coolant passage is blocked. Since the second temperature is set to be equal to or lower than the first temperature, the first valve is also closed at this time, and the inflow of the cooling water from the main circulation passage to the engine cooling water passage is blocked. Therefore, the cooling water is blocked from the main circulation passage, the bypass passage, and the heat receiving and radiating passage at the junction, and does not flow into the engine cooling water passage.

  On the other hand, when the temperature of the cooling water is equal to or higher than the second temperature, the second main body portion is separated from the second seat portion, the second valve is opened, and the engine from the cooling water bypass passage and the heat receiving / radiating passage Inflow into the cooling water passage becomes possible. At this time, if the temperature of the cooling water is lower than the first temperature, the first valve continues to close, and the inflow of the cooling water from the main circulation passage to the engine cooling water passage continues to be blocked. Therefore, the cooling water can flow into the engine cooling water passage from each of the bypass passage and the heat receiving and radiating passage through the second region, but cannot flow into the engine cooling water passage from the main circulation passage.

  Then, when the temperature of the cooling water becomes equal to or higher than the first temperature, the first valve is opened as described above. For this reason, the cooling water can flow into the engine cooling water passage from the main circulation passage, the bypass passage, and the heat receiving and radiating passage through the junction.

  The invention according to claim 6 is the invention according to claim 4 or 5, wherein at least one of the partition wall and the second main body portion is seated on the second seat portion of the second main body portion. It is assumed that a communication portion that allows the cooling water to flow between the second region and the first region is provided.

  According to the above configuration, under the temperature condition where the second main body portion is seated on the second seat portion and the second valve is closed, the first valve is closed as described above, and the main circulation passage of the cooling water To the engine cooling water passage is blocked. At this time, assuming that the inflow of the coolant from the bypass passage and the heat receiving / dissipating passage to the engine coolant passage is completely blocked by the closing of the second valve, the thermal actuator increases the temperature of the coolant in the internal combustion engine. It takes time to detect, and there is concern that the temperature will rise too much. On the other hand, in claim 6, the cooling water in the second region can flow into the first region through the communicating portion even when the second valve is closed. Therefore, it is possible to prevent the temperature of the internal combustion engine from becoming excessively high by causing the thermal actuator to sense the temperature rise of the cooling water in the internal combustion engine at an early stage.

  In the invention according to claim 7, in the invention according to claim 5, when the temperature of the cooling water is equal to or higher than a third temperature set higher than the first temperature, It is assumed that the connecting portion of the bypass passage in the second region is closed.

  According to said structure, the connection part of the bypass channel in a 2nd area | region is open | released as the temperature of the cooling water in a junction part is less than 3rd temperature. For this reason, inflow from the bypass passage of the cooling water to the second region is possible. At this time, if the temperature of the cooling water is lower than the second temperature, the second main body portion is seated on the second seat portion as described above, so that the cooling water flows into the engine cooling water passage from the second region. Is cut off. On the other hand, if the temperature of the cooling water is equal to or higher than the second temperature, the second main body portion is separated from the second seat portion, so that the cooling water can flow into the engine cooling water passage from the second region. It is.

  On the other hand, when the temperature of the cooling water is equal to or higher than the third temperature, the connection portion of the bypass passage in the second region is closed by the second main body portion. Accordingly, the cooling water is blocked from flowing from the bypass passage into the second region, and thus the first region and the engine cooling water passage. Therefore, it is possible to efficiently cool the internal combustion engine by actively guiding the cooling water having passed through the radiator and having a low temperature to the engine cooling water passage.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
In the internal combustion engine 11 in FIG. 2, the air / fuel mixture is combusted in the combustion chamber. Part of the heat energy generated by this combustion is converted into power. A part of the heat energy that is not converted into motive power is lost together with the exhaust or as a friction loss, and the rest is absorbed by each part of the internal combustion engine 11. In order to prevent the internal combustion engine 11 from being overheated by the absorbed heat, a water cooling type cooling device 12 shown below is provided.

  A water jacket 13 is provided inside the internal combustion engine 11 as an engine cooling water passage. A water pump (W / P) 14 is disposed at or near the inlet of the water jacket 13. An upstream end of a main circulation passage 16 having a radiator 15 is connected to the outlet of the water jacket 13. The downstream end of the main circulation passage 16 is connected to the water pump 14 via a junction 17 and a water pump inlet passage 18. Then, by the operation of the water pump 14, the cooling water circulates in the main circulation passage 16 in the clockwise direction in FIG. 1 starting from the water pump 14 (see the arrow in FIG. 1). The cooling water absorbs the heat of the internal combustion engine 11 in the process of passing through the water jacket 13 and rises in temperature. The heated cooling water releases heat when it passes through the radiator 15.

  A bypass passage 19 that bypasses the radiator 15 is connected to the main circulation passage 16. The upstream end of the bypass passage 19 is connected between the radiator 15 and the outlet of the water jacket 13 in the main circulation passage 16, and the downstream end is connected to the junction portion 17.

  In addition to the bypass passage 19, a heater passage 21 is provided as a heat receiving and radiating passage that bypasses the radiator 15. In the heater passage 21, the cooling water flowing through the passage 21 is led to the heater core (heating heat exchanger) of the hot water heater (heating device) 22 as a heat source. The upstream end of the heater passage 21 is connected between the outlet of the water jacket 13 and the radiator 15 in the main circulation passage 16, and the downstream end is connected to the junction portion 17.

  Accordingly, the cooling water flowing through each of the main circulation passage 16, the bypass passage 19, and the heater passage 21 passes through the junction 17 and is then guided to the water jacket 13 through the water pump inlet passage 18 and the water pump 14.

  In the present embodiment, the housing of the existing cooling device is used as it is as the housing 24 having the junction portion 17 to which the main circulation passage 16, the bypass passage 19, the heater passage 21, and the water pump inlet passage 18 are connected. .

  The junction 17 is provided with a switching valve 23 for switching the communication state between each of the main circulation passage 16, the bypass passage 19 and the heater passage 21 and the water jacket 13 (water pump inlet passage 18).

  FIG. 1 shows a cross-sectional structure of the switching valve 23 and its surroundings. The housing 24 is provided with the junction 17 described above. The merging portion 17 is formed of a cylindrical recess, and is open on the outer wall surface of the housing 24 (the right side surface in FIG. 1). At the opposite locations (upper and lower sides in FIG. 1) on the inner peripheral surface of the merging portion 17, the downstream end of the heater passage 21 provided in the housing 24 and the upstream end of the water pump inlet passage 18 are opened. ing. In addition, a downstream end of the bypass passage 19 provided in the housing 24 is opened on the bottom surface of the merging portion 17. Further, the downstream end of the main circulation passage 16 is connected to the opening portion of the merging portion 17 in the housing 24. That is, the pipe 25 is attached to the outer wall surface of the housing 24 so as to cover the opening portion of the merging portion 17, and the internal space of the pipe 25 forms the main circulation passage 16.

  A thermal actuator 31 that is deformed in accordance with the temperature of the cooling water (cooling water temperature THW) is supported by the pair of support members 28 and 29 inside the junction portion 17. The thermal actuator 31 includes a pellet 32 and a spindle 33 as main components. The pellets 32 and the spindle 33 extend in the direction connecting the openings of the bypass passage 19 and the main circulation passage 16 in the merging portion 17 (left-right direction in FIG. 1). In the pellet 32, wax (not shown) whose volume is changed according to temperature is enclosed. The volume change here means that the volume is small (shrinks) when the cooling water temperature THW is low, and the volume increases (expands) as the cooling water temperature THW rises. The wax preferably has a volume proportional or substantially proportional to the temperature.

  The pellet 32 is slidably inserted into the support member 28. On the other hand, the spindle 33 is accommodated in the pellet 32 so as to be able to appear and retract, and an end portion (right end portion in FIG. 1) protruding from the pellet 32 is locked to the support member 29. Accordingly, when the volume of the wax changes according to the temperature, the pellet 32 is displaced along with the change.

  A partition wall 34 that divides the internal space into two regions (a first region Z1 and a second region Z2) is disposed in the merge portion 17. The partition wall 34 has a substantially cylindrical shape with a bottom that opens at one end (the right end in FIG. 1), and surrounds the support member 28. The partition wall 34 is locked to the inner peripheral surface or the like of the merging portion 17 at the opening portion. In the merging portion 17, the space inside the partition wall 34 forms the first region Z1, and the outer space forms the second region Z2.

  The partition wall 34 is provided with a communication hole 35 that allows the internal space (first region Z1) and the water pump inlet passage 18 to always communicate with each other. For this reason, the flow of the cooling water from the first region Z1 to the water pump inlet passage 18 is possible. Further, most of the outer peripheral surface of the partition wall 34 has a cylindrical shape and is in contact with the inner peripheral surface of the merging portion 17, but only a part (upper part of FIG. 3) has a flat surface and is in the same shape. Separated from the circumferential surface. Due to the shape of the partition wall 34, the heater passage 21 and the second region Z2 are always connected, and cooling water can flow into the second region Z2 from the heater passage 21.

  The switching valve 23 opens and closes in response to the deformation of the thermal actuator 31 to connect or block the main circulation passage 16 and the first region Z1 in order to connect or block the main circulation passage 16 and the water jacket 13. I have. The first valve 36 is attached to the first seat portion 37 attached to the opening portion of the merging portion 17 and the end of the pellet 32 on the side of the main circulation passage 16 and extends and contracts the thermal actuator 31 according to the cooling water temperature THW. A first main body portion 38 that is displaced in association with the first seat portion 37 and moves away from the first seat portion 37 is provided. The attachment position of the first seat portion 37 is between the connection portion of the main circulation passage 16 and the connection portion of the water pump inlet passage 18 in the first region Z1. As the first main body 38, a relatively large thickness is used. This is because the first main body 38 is separated from the first seat portion 37 on the condition that the coolant temperature THW rises from the state of FIG. 1 and the thermal actuator 31 extends to some extent.

  Here, the opening and closing timing of the first valve 36 differs depending on the location of the first main body 38 attached to the pellet 32, but the location in the present embodiment is only when the cooling water temperature THW is lower than the first temperature THW1. The first main body portion 38 is set at a position where the first valve portion 36 is seated on the first seat portion 37 (see FIG. 6). A return spring 39 is interposed in a compressed state between the first main body portion 38 and the support member 28 on the outer periphery of the pellet 32, and the first main body portion 38 is always biased toward the main circulation passage 16 side. Has been.

  The switching valve 23 opens and closes in response to deformation of the thermal actuator 31 to connect or block the bypass passage 19 and the water jacket 13, and to connect or block the heater passage 21 and the water jacket 13. A second valve 41 is provided for communicating or blocking the two regions Z2. The second valve 41 includes a second seat portion 42 and a second main body portion 43. The second main body portion 43 is formed by dividing a part of the bottom portion of the partition wall 34, and is slidably mounted on the pellet 32. A stopper (not shown) for preventing the second main body portion 43 from falling off from the pellet 32 is provided at the end of the pellet 32 on the bypass passage 19 side. The second sheet portion 42 is constituted by a peripheral portion of a hole generated in the bottom portion of the partition wall 34 due to the division of the second main body portion 43. In the second valve 41 having such a configuration, the second main body portion 43 is displaced and seated on or separated from the second seat portion 42 as the thermal actuator 31 expands and contracts according to the coolant temperature THW.

  Here, the opening and closing timing of the second valve 41 differs depending on the location of the second main body 43 with respect to the pellet 32, but the location in the present embodiment is the location where the following conditions (1) and (2) are satisfied. (See FIG. 6).

  Condition (1): A location where the second valve 41 is closed by being seated on the second seat portion 42 only when the coolant temperature THW is lower than the second temperature THW2 set to be equal to or lower than the first temperature THW1. .

  Condition (2): A location where the coolant temperature THW is seated on the third seat portion 44 when the coolant temperature THW is equal to or higher than the third temperature THW3 set higher than the first temperature THW1. The third seat portion 44 is a location around the connection portion of the bypass passage 19 in the second region Z2.

  A spring 45 is interposed between the outer periphery of the pellet 32 and the intermediate portion in the longitudinal direction of the pellet 32 and the second main body portion 43 in a compressed state. It is biased toward the bypass passage 19 side.

Next, the effect | action of the cooling device 12 comprised as mentioned above is demonstrated with reference to FIG.1 and FIG.4-FIG.6.
FIG. 1 shows the state of the switching valve 23 when the coolant temperature THW is low (THW <THW2), such as when the internal combustion engine 11 is started at a low temperature. In this state, the thermal actuator 31 is most contracted, and the pellet 32 is positioned closest to the main circulation passage 16. The first main body portion 38 is seated on the first seat portion 37 (more precisely, completely fitted into the first seat portion 37), and the first valve 36 is closed. The main circulation passage 16 and the first region Z1 are blocked by the first main body 38 seated in this way. For this reason, the inflow from the main circulation passage 16 of the cooling water to the first region Z1, and consequently the water pump inlet passage 18 and the water jacket 13 is blocked.

  Further, in the above state, the second main body 43 is seated on the second seat portion 42, the second valve 41 is closed, and the first region Z1 and the second region Z2 are shut off. For this reason, the inflow of the coolant from the bypass passage 19 and the heater passage 21 to the first region Z1, and consequently the water pump inlet passage 18 and the water jacket 13 is blocked.

  In this way, the inflow of the cooling water to the water jacket 13 through the main circulation passage 16, the bypass passage 19 and the heater passage 21 is blocked, and the cooling water in the internal combustion engine 11 only circulates with the operation of the water pump 14. is there. Therefore, the heat generated around the combustion chamber is not easily taken away by the cooling water, and each part of the engine, particularly the vicinity of the combustion chamber, is preferentially warmed, and the temperature of that part rises. As a result, the combustion state can be improved, and the combustion state at the time when the warm-up is completed can be made early.

  When the cooling water temperature THW rises within the range of THW2 ≦ THW <THW1 from the state of FIG. 1, the pellet 32 starts to be displaced toward the bypass passage 19 due to the volume expansion of the wax (the thermal actuator 31 begins to expand). Along with this, the first main body portion 38 and the second main body portion 43 are integrated with the pellet 32 and start to be displaced in the same direction.

  As shown in FIG. 4, when the second main body 43 is separated from the second seat portion 42 and the second valve 41 is opened due to the displacement, the first region Z1 and the second region Z2 are in communication. As indicated by solid arrows in FIG. 4, the cooling water flowing through the bypass passage 19 and the heater passage 21 can flow into the water pump inlet passage 18 and the water jacket 13 through the second region Z2 and the first region Z1, respectively. Become.

  At this time, the first main body 38 is also displaced in the same direction (left side in FIG. 4). However, since the first main body 38 has a certain thickness, the first main body 38 is slightly displaced. It is not separated from the 1st sheet | seat part 37 only by doing. Since the first valve 36 continues to close, the inflow of the cooling water from the main circulation passage 16 into the first region Z1 continues to be blocked.

  Therefore, not the cooling water that has passed through the radiator 15 in the process of flowing through the main circulation passage 16 and the cooling water temperature THW has decreased, but the cooling water that has flowed through the bypass passage 19 and the heater passage 21 flows into the water jacket 13. Warm-up of the internal combustion engine 11 is promoted. Further, since the coolant flows through the bypass passage 19 and the heater passage 21 when the coolant temperature THW rises to some extent (THW2 ≦ THW), the temperature of the internal combustion engine 11 is set by setting the second temperature THW2 to an appropriate value. An excessively high problem can be prevented.

  When the coolant temperature THW rises and THW1 ≦ THW <THW3, the first main body portion 38 is separated from the first seat portion 37, the first valve 36 is opened, and the first region Z1 and the main circulation passage 16 are opened. Is communicated. For this reason, in addition to the bypass passage 19 and the heater passage 21, the water jacket 13 of the cooling water flowing through the main circulation passage 16 can be introduced.

  At this time, the degree of cooling of the internal combustion engine 11 by the cooling water varies depending on the ratio of the amount of cooling water flowing into the water jacket 13 from the main circulation passage 16, the bypass passage 19 and the heater passage 21. That is, the cooling water temperature THW for cooling the internal combustion engine 11 decreases as the proportion of the cooling water flowing into the water jacket 13 occupies the cooling water from the main circulation passage 16 increases.

  Further, when the coolant temperature THW rises and becomes equal to or higher than the third temperature THW3, as shown in FIG. 5, the second main body portion 43 is seated on the third seat portion 44 and the bypass passage 19 is closed. Inflow from the cooling water bypass passage 19 to the water jacket 13 is blocked. At this time, since the main circulation passage 16 and the first region Z1 are communicated with each other, and the first region Z1 and the second region Z2 are communicated, the water of the cooling water flowing through the main circulation passage 16 and the heater passage 21 respectively. Inflow into the jacket 13 is possible. As described above, in the state where the second main body portion 43 is seated on the third seat portion 44, further displacement toward the bypass passage 19 is prevented, but the pellet 45 is compressed by the spring 45 being compressed. Is allowed to be displaced toward the bypass passage 19.

According to the embodiment described in detail above, the following effects can be obtained.
(1) A thermal actuator 31 that is deformed according to the cooling water temperature THW is disposed in the merging portion 17, and a first valve 36 and a second valve 41 that open and close according to the deformation of the thermal actuator 31 are provided.

  Accordingly, the relationship between the coolant temperature THW and the opening / closing timings of the first and second valves 36 and 41 is appropriately set in advance, so that the coolant circulation temperature THW is low (THW <THW2). 16, each of the bypass passage 19 and the heater passage 21 and the water jacket 13 can be shut off. These interruptions confine the heat generated by the combustion of the air-fuel mixture when the internal combustion engine 11 is started at a low temperature, preferentially warm up each part of the internal combustion engine 11, and the heat diffuses into the passages 16, 19, 21. Can be suppressed.

  Further, the passages 16, 19, and 21 and the water jacket 13 are blocked by the thermal actuator 31 deforming (extending / contracting) in accordance with the change in the coolant temperature THW. Therefore, unlike the background art, driving means such as a motor for driving the switching valve and control for operating the driving means become unnecessary. Thus, according to the present embodiment, the internal combustion engine 11 can be warmed up early at the time of low-temperature start-up with a simple configuration.

  (2) The first main body portion 38 is set to be seated on the first seat portion 37 only when the cooling water temperature THW is lower than the first temperature THW1, and the second main body portion 43 is set so that the cooling water temperature THW is first. It is set so as to be seated on the second seat portion 42 only when the temperature is less than the two temperatures THW2 (≦ THW1). With these settings, when the coolant temperature THW is in the range of THW2 ≦ THW <THW1, the second valve 41 is opened with the first valve 36 closed.

  For this reason, cooling water is allowed to flow from the bypass passage 19 into the water jacket 13 instead of the main circulation passage 16, and the cooling water having a low cooling water temperature THW is prevented from flowing through the water jacket 13 and excessively cooling the internal combustion engine 11. can do. Therefore, even when the coolant temperature THW is low immediately after the internal combustion engine 11 is started, the internal combustion engine 11 can be warmed up early (warming up time can be shortened).

  (3) When the coolant temperature THW is equal to or higher than the third temperature THW3 (≧ THW1), the second main body 43 is configured to close the connection portion of the bypass passage 19 in the second region Z2. Therefore, by setting the third temperature THW3 to an appropriate value, the cooling water is prevented from flowing from the bypass passage 19 into the water jacket 13 when the cooling water temperature THW is high, and passes through the radiator 15 to pass through the cooling water temperature THW. Therefore, the internal combustion engine 11 can be efficiently cooled by actively guiding the cooling water having a low temperature to the water jacket 13.

  (4) In the present embodiment, the structure of the switching valve 23 is devised, but a special structure is not adopted for the junction portion 17 in which the switching valve 23 is incorporated. For this reason, the cooling device 12 can be established by diverting an existing housing having a merging portion and incorporating the switching valve 23 into the merging portion. Since the cooling water passages such as the main circulation passage 16, the bypass passage 19, the heater passage 21, and the water pump inlet passage 18 do not need to be changed, it is easy to realize.

Note that the present invention can be embodied in another embodiment described below.
In the above-described embodiment, the cooling water in the second region Z2 is reliably prevented from leaking to the water pump inlet passage 18 through the gap between the partition wall 34 and the inner peripheral surface of the merging portion 17 (see A in FIG. 1). For this purpose, a seal member made of rubber or the like may be disposed in the same gap.

  In the above embodiment, when the cooling water temperature THW is lower than the second temperature THW2 and the valves 36 and 41 are closed, each of the main circulation passage 16, the bypass passage 19, the heater passage 21, and the water jacket 13. And do not have to be completely blocked. This is because in the state where the cooling water is not circulated at all, it takes time until the thermal actuator 31 senses the temperature rise around the combustion chamber, and there is a concern that the temperature will rise too much. From this point of view, it may be preferable to circulate a certain amount of cooling water rather than circulating cooling water at all. Therefore, when the second main body 43 is seated on the second seat portion 42, the partition wall 34 and the second main body portion are arranged so that a small amount of cooling water can flow between the first region Z1 and the second region Z2. At least one of 43 may be provided with a communicating portion that allows the two regions Z1 and Z2 to communicate with each other when the second main body portion 43 is seated on the second seat portion. For example, a gap may be formed between the second body portion 43 and the bottom portion of the partition wall 34 when the second body portion 43 is seated on the second seat portion 42. Moreover, you may make a small diameter hole in 2nd main-body part 43 itself or the partition wall 34. FIG. These gaps and holes correspond to communication portions.

  In addition to the heater passage 21 described above, the heat receiving and radiating passage connected to the merging portion 17 includes a throttle body hot water passage, an EGR (exhaust gas recirculation) cooler passage, an automatic transmission hydraulic oil warmer (transmission oil cooler) passage, hot water A heating-type hot air intake passage may be used. In the throttle body warm water passage, the throttle body is warmed by the cooling water (hot water) flowing through the passage, so that the operation of the throttle valve and the like is stabilized during extremely cold weather. In the EGR cooler passage, the components of the EGR device, the intake passage (particularly, the intake manifold) and the like are cooled by the cooling water flowing through the passage. In the hydraulic oil warmer passage, the cooling water (warm water) flows through the hydraulic oil warmer, and when cold, the hydraulic oil of the automatic transmission is warmed early and the friction of the automatic transmission is reduced. The hydraulic oil warmer functions as an oil cooler when the hydraulic oil temperature is high. In the hot air intake passage, the intake air is warmed in the process in which the cooling water passes through the heater core provided in the vicinity of the air cleaner.

  -This invention is applicable also to the cooling device which connected the some heat receiving / radiating passage to the confluence | merging part.

Sectional drawing which shows the state of the switching valve | bulb when the cooling water temperature THW is less than 2nd temperature THW2, and its peripheral location in one Embodiment of this invention. The schematic diagram which shows the structure of a cooling device. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. Sectional drawing which shows the state of the switching valve | bulb when the cooling water temperature THW is 2nd temperature THW2 or more and less than 1st temperature THW1, and its peripheral location. Sectional drawing which shows the state of the switching valve | bulb when the cooling water temperature THW is 3rd temperature THW3 or more, and its peripheral location. The characteristic view which shows the relationship between cooling water temperature and the flow volume of the cooling water in each channel | path. The systematic diagram which shows the cooling device in background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Internal combustion engine, 12 ... Cooling device, 13 ... Water jacket (engine cooling water passage), 15 ... Radiator, 16 ... Main circulation passage, 17 ... Junction part, 19 ... Bypass passage, 21 ... Heater passage (radiation / radiation passage) , 31 ... thermal actuator, 34 ... partition wall, 36 ... first valve, 37 ... first seat portion, 38 ... first body portion, 41 ... second valve, 42 ... second seat portion, 43 ... second body portion. THW ... cooling water temperature, THW1 ... first temperature, THW2 ... second temperature, THW3 ... third temperature, Z1 ... first region, Z2 ... second region.

Claims (7)

A cooling device for use in an internal combustion engine in which a downstream end of a main circulation passage having a radiator and a downstream end of a bypass passage and a heat receiving and radiating passage each bypassing the radiator are connected to an engine coolant passage through a junction. ,
A thermal actuator disposed in the junction and deformed according to the temperature of the cooling water;
A first valve that opens and closes in response to deformation of the thermal actuator to communicate or block the main circulation passage and the engine coolant passage;
A second valve that opens and closes according to the deformation of the thermal actuator, and connects or blocks the bypass passage and the engine coolant passage, and connects or blocks the heat receiving / radiating passage and the engine coolant passage. A cooling device for an internal combustion engine characterized by the above. A first region where the downstream end of the main circulation passage and the upstream end of the engine cooling water passage are connected to each other in the junction, and a second region where the downstream ends of the bypass passage and the heat receiving / dissipating passage are connected. There is a partition wall that separates the area,
The first valve is displaced in accordance with the deformation of the first seat portion provided between the connection portion of the main circulation passage and the connection portion of the engine coolant passage in the first region, and the thermal actuator. The cooling device for an internal combustion engine according to claim 1, further comprising a first main body portion that is seated on or separated from the first seat portion. 3. The internal combustion engine according to claim 2, wherein the first main body portion is attached to the thermal actuator and is seated on the first seat portion only when the temperature of the cooling water is lower than the first temperature. Cooling system. The said 2nd valve | bulb is provided with the 2nd sheet | seat part provided in the said partition wall, and the 2nd main-body part which displaces with the deformation | transformation of the said thermosensitive actuator, and seats on or separates from the said 2nd sheet | seat part. Or the cooling apparatus for an internal combustion engine according to 3. The second body portion is attached to the thermal actuator and is seated on the second seat portion only when the temperature of the cooling water is lower than a second temperature set to be equal to or lower than the first temperature. The cooling device for an internal combustion engine according to claim 4. At least one of the partition wall and the second main body portion allows the cooling water to flow between the second region and the first region when the second main body portion is seated on the second seat portion. The cooling device for an internal combustion engine according to claim 4 or 5, wherein a communication portion is provided. The second body portion closes a connection portion of the bypass passage in the second region when the temperature of the cooling water is equal to or higher than a third temperature set higher than the first temperature. 5. A cooling device for an internal combustion engine according to 5.

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