JP2011252453A - Cooling device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine, which has a valve for switching a circulation mode of cooling water in a water jacket formed in a cylinder block and a cylinder head and realizes miniaturization of the internal combustion engine including the valve more easily.SOLUTION: The cooling device of the internal combustion engine includes: a cooling water circulation path for serially circulating the cooling water to a block side water jacket 21 and a head side water jacket 31; a merging part 32 for merging the cooling water passed through the each water jacket 21, 31; and a thermostat valve 70 for opening and closing an outlet passage of the block side water jacket 21 according to water temperature of the merging part 32. The thermostat valve 70 and the merging part 32 are arranged in the cylinder head 30.

Description

  The present invention relates to a cooling device for a water-cooled internal combustion engine.

  2. Description of the Related Art Conventionally, in an internal combustion engine for an automobile, a cooling device for an internal combustion engine in which cooling water is circulated in parallel with respect to a water jacket of a cylinder head and a water jacket of a cylinder block has been proposed (for example, see Patent Document 1). ). This type of internal combustion engine cooling device includes a valve that circulates only the cooling water in the water jacket of the cylinder head while stopping the circulation of the cooling water in the water jacket of the cylinder block. And by performing such a circulation of cooling water at the time of a cold start of an internal combustion engine, it becomes possible to warm a cylinder block rapidly, suppressing the temperature rise of the combustion chamber wall of a cylinder head. As a result, knocking is suppressed, emissions are improved, and fuel consumption is improved by reducing cylinder friction loss.

Japanese Patent Laid-Open No. 5-86970

  In the cooling device for an internal combustion engine disclosed in Patent Document 1, a valve for stopping the circulation of the cooling water in the water jacket of the cylinder block is attached to the outside of the cylinder block. For this reason, there exists a problem that the physique of the internal combustion engine including the said valve tends to enlarge.

  The present invention was devised in view of such problems, and in the cooling device for an internal combustion engine provided with a valve for switching the circulation mode of the cooling water in the water jacket formed in the cylinder block and the cylinder head, the valve It is an object of the present invention to provide a cooling apparatus for an internal combustion engine that facilitates downsizing of the internal combustion engine including the engine.

  In order to achieve the above object, a cooling apparatus for an internal combustion engine of the present invention is configured as follows.

  That is, the cooling device for an internal combustion engine according to the present invention switches the block-side water jacket formed in the cylinder block, the head-side water jacket formed in the cylinder head, and the circulation mode of the cooling water in the water jacket. It is premised on what is provided with a valve, The said valve is provided in the said cylinder head, It is characterized by the above-mentioned.

  According to the cooling apparatus for an internal combustion engine having such a configuration, since the valve for switching the circulation mode of the cooling water in the water jacket is provided in the cylinder head, the valve is installed outside the cylinder head or the cylinder block. Compared with the case where it is, it becomes easy to implement | achieve size reduction of the internal combustion engine including the said valve.

  A cooling water circulation path for circulating cooling water in parallel to the block side water jacket and the head side water jacket; and a merging portion for merging the cooling water that has passed through the water jackets. It is desirable that the portion is provided in the cylinder head.

  According to the cooling apparatus for an internal combustion engine having such a configuration, since the merging portion is provided in the cylinder head together with the valve, piping for providing the merging portion outside the cylinder head or the cylinder block is not required. Furthermore, it becomes easy to realize downsizing of the internal combustion engine.

  In addition, switching of the circulation mode of the cooling water in the water jacket includes, for example, a mode in which the cooling water is circulated in parallel to the block side water jacket and the head side water jacket, and a circulation of the cooling water in the block side water jacket. Is switched to a mode in which the cooling water of the head side water jacket is circulated. And the said valve switches the circulation mode of the said cooling water by opening and closing the exit flow path of the said block side water jacket according to the water temperature of the cooling water which flows through the said confluence | merging part. Is desirable.

  Further, it is desirable that the valve is a thermostat valve and the temperature sensing part is provided in the junction part.

  According to the cooling apparatus for an internal combustion engine having such a configuration, since the merging portion also serves as an installation space for the temperature sensing portion of the thermostat valve, the internal combustion engine can be further reduced in size.

  According to the cooling apparatus for an internal combustion engine of the present invention, since the valve for switching the circulation mode of the cooling water in the water jacket is provided in the cylinder head, the valve is installed outside the cylinder head or the cylinder block. Compared with the case, it becomes easy to realize downsizing of the internal combustion engine including the valve.

It is the schematic which shows the cooling device of the internal combustion engine which concerns on embodiment of this invention. It is a figure equivalent to the AA cross section of the cylinder head of FIG. 1, Comprising: It is a figure which shows the form of a specific head side water jacket. It is a figure which shows the state which isolate | separated the thermostat valve and the branch pipe with respect to the cylinder head.

  Hereinafter, a cooling device for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings. As an internal combustion engine in the present embodiment, an in-line four-cylinder engine will be described as an example.

  As shown in FIG. 1, the cooling device for the engine 10 includes a water jacket 21 (hereinafter also referred to as “block-side water jacket 21”) formed in the cylinder block 20 and a water jacket formed in the cylinder head 30. 31 (see FIG. 2; hereinafter also referred to as “head-side water jacket 31”). The head side water jacket 31 is not shown in FIG.

  Cooling water discharged from the water pump 40 is introduced from the cooling water inlet 22 of the cylinder block 20 to the front portion of the block-side water jacket 21 (around the cylinder 51 arranged at one end position in the cylinder arrangement direction). Then, when the second thermostat valve 70, which will be described later, is opened, the introduced cooling water is diverted in front of the cylinder 51, a part of which flows in the block-side water jacket 21, and the remaining part is It flows to the head side water jacket 31 side.

  The cooling water flowing in the block-side water jacket 21 flows from the front (one side) to the rear (the other side) in the cylinder arrangement direction along both sides of each of the cylinders 51 to 54, as indicated by arrows 91 and 92. It merges behind the cylinder 54. The cooling water that has reached the rear of the cylinder 54 is connected to the communication hole 62 formed in the gasket 60 interposed between the cylinder block 20 and the cylinder head 30, and the merge guide channel 39 formed in the cylinder head 30. And the coolant that has passed through the head-side water jacket 31 merges at the junction 32 in the cylinder head 30. That is, in the engine 10, a cooling water circulation path for circulating cooling water in parallel through the block-side water jacket 20 and the head-side water jacket 30 is formed.

  The cooling water in the head-side water jacket 31 flows from the front (one side) to the rear (the other side) in the cylinder arrangement direction along the combustion chamber walls of the cylinders 51 to 54 as indicated by arrows 93. Then, it merges with the cooling water that has passed through the block-side water jacket 21 at the merging portion 32, and goes out of the cylinder head 30 through the outlet opening 33.

  A second thermostat valve 70 is installed at the junction 32. The second thermostat valve 70 switches the circulation mode of the cooling water in the block-side water jacket 21 and the head-side water jacket 31. Specifically, the second thermostat valve 70 opens and closes the outlet flow path of the block-side water jacket 21 based on the coolant temperature in the merging portion 32, and circulates the coolant in the block-side water jacket 21, Alternatively, it is provided to stop the circulation. The second thermostat valve 70 is closed at a temperature lower than the water temperature Tc (for example, Tc = 75 ° C.), opened at the water temperature Tc or higher, and fully opened at the water temperature Tcw (for example, Tcw = 85 ° C.) or higher.

  Cooling water that has flowed out of the cylinder head 30 through the outlet opening 33 branches at the branch point 41 if the first thermostat valve 43 is open, and part of the coolant passes through the radiator 82 and the first thermostat valve 43. Then, it returns to the water pump 40. Further, the surplus portion returns to the water pump 40 via the heater 44 and the first thermostat valve 43. On the other hand, when the first thermostat valve 43 is closed, the cooling water that has flowed out of the cylinder head 30 through the outlet opening 33 does not circulate through the radiator 82, and does not pass through the heater 44 and the first thermostat valve 43. It returns to the water pump 40 via. The first thermostat valve 43 is closed at a temperature lower than the water temperature Tw (for example, Tw = 88 ° C.), is opened at the water temperature Tw or higher, and is fully opened at the water temperature Tww (for example, Tww = 94 ° C.) or higher.

  Next, a specific structure in the cylinder head 30 will be described with reference to FIG. FIG. 2 shows a specific example of the AA cross-sectional view of FIG. For convenience of explanation, the upstream side of the cooling water flowing in the head-side water jacket 31 is referred to as “front” of the engine 10, and the downstream side is referred to as “rear” of the engine 10. Also, the direction from which exhaust gas is discharged from the exhaust port is referred to as “exhaust side”, and the direction from which fresh air is drawn from the intake port is referred to as “intake side”.

  As shown in FIG. 2, the head side water jacket 31 extends in the cylinder arrangement direction in the cylinder head 30. A communication path 61 communicating with the block-side water jacket 21 is formed at the front end of the head-side water jacket 31, and cooling water flows into the head-side water jacket 31 from the block-side water jacket 21 through the communication path 61. To do. The communication path 61 is configured by a through hole or the like formed at a predetermined position of the gasket 60.

  The rear end portion of the head-side water jacket 31 is formed on the exhaust side of a merging guide channel 39, which will be described later, and the downstream end thereof opens toward the intake side behind the merging guide channel 39.

  The merging guide channel 39 is a relatively short cooling water channel formed in the front-rear direction of the engine 10 from the communication hole 62 to the merging portion 32. The merging guide channel 39 guides the cooling water supplied from the block-side water jacket 21 through the communication hole 62 to the rear, and the cooling water supplied from the opening at the rear end of the head-side water jacket 31. And merge at the junction 32. Immediately behind the merging portion 32, an outlet opening 33 for discharging the merged cooling water to the outside of the cylinder head 30 is formed.

  In FIG. 2, reference numeral 34 denotes an exhaust port passage, reference numeral 35 denotes an intake port passage, and reference numeral 36 denotes a spark plug opening.

  In the present embodiment, the communication hole 62, the merging guide channel 39, and the merging portion 32 are unevenly distributed on the intake side (in FIG. 2, the intake side from the center line passing through the centers of the four cylinders 51 to 54). The rear end portion of the head-side water jacket 31 is formed on the exhaust side of the merging guide channel 39, but the communication hole 62, the merging guide channel 39 and the merging portion 32 are unevenly distributed on the exhaust side, and the head The rear end portion of the side water jacket 31 is formed on the intake side of the merging guide channel 39, and the downstream end of the head side water jacket 31 is opened toward the rear side and the exhaust side of the merging guide channel 39. Also good.

  As shown in FIG. 2, the second thermostat valve 70 includes a valve body 71, a temperature sensing part 72, a flange part 73, a piston part 74, and the like, and is installed from the joining guide channel 39 to the joining part 32. . The flange portion 73 of the second thermostat valve 70 includes a seating surface 38 formed toward the rear outlet opening 33 in the cylinder head 30 and an end portion of the branch pipe 45 (an insertion tube portion 451 of the branch pipe 45 described later). It is sandwiched between the end portions 451b).

  The temperature sensing part 72 is provided in the junction part 32 and opens and closes the valve element 71 in response to the temperature of the cooling water flowing through the junction part 32. The valve body 71 is fixed to a piston part 74 that is operated by the expansion / contraction force of wax in the temperature sensing part 72, and a flow path of cooling water flowing from the block-side water jacket 21 side to the merging part 32 is provided. It is installed so as to open and close in the merging guide channel 39.

  A branch pipe 45 as shown in FIG. 3 is attached to the outlet opening 33. The branch pipe 45 includes a flange portion 452 fixed around the outlet opening 33 with a bolt or the like, and an insertion cylinder portion 451 provided in front of the flange portion 45 and inserted into the cylinder head 30 from the outlet opening 33. And branch pipes 453 and 454 that are provided behind the flange portion 452 and branch the cooling water fed from the outlet opening 33 to the radiator 42 side and the heater 44 side.

  The insertion tube portion 451 has an opening 451 a facing the downstream end of the head-side water jacket 31 on the side surface. From the opening 451a, cooling water flows from the head side water jacket 31 side. Further, as described above, the distal end surface 451b of the insertion tube portion 451 holds the flange portion 73 of the second thermostat valve 70 together with the seat surface 38 in the cylinder head 30.

  According to the cooling apparatus for an internal combustion engine according to the embodiment of the present invention described above, since the second thermostat valve 70 is provided in the cylinder head 30, the second thermostat valve 70 is provided in the cylinder head 30 or the cylinder block 20. The size of the engine 10 including the second thermostat valve 70 can be easily reduced as compared with the case where it is installed outside the engine. That is, when the second thermostat valve 70 is installed outside the cylinder head 30 or the cylinder block 20, the physique of the engine (the engine including the cover and piping) is equal to the volume of the second thermostat valve 70 and its covers and piping. Physique) is likely to increase.

  In addition, since the cover and piping are not required, the number of parts, the number of steps for mounting the covers, and the associated cost reduction can be relatively reduced.

  Further, according to the cooling apparatus for an internal combustion engine according to the embodiment of the present invention, the merging portion 32 is provided in the cylinder head 30 together with the second thermostat valve 70, and therefore the size of the engine 10 can be further reduced in size. Become. That is, in the case where the merging portion 32 is provided outside the cylinder head 30 or the cylinder block 20, it is necessary to install piping for forming the merging portion outside the cylinder head 30 or the cylinder block 20. There is a high possibility that the physique of the engine (the physique of the engine including the piping) will increase by the installation space.

  Moreover, since piping for forming the merge portion is not required, it is possible to relatively reduce the number of parts, reduce the man-hours for installing the piping, and reduce costs associated therewith.

  In the cooling device for an internal combustion engine according to the embodiment of the present invention, the downstream end of the head-side water jacket 31 opens toward the rear side of the merging guide channel 39 and toward the intake side, and further, the merging portion 32. Since the outlet opening 33 is formed immediately after the rear, the cooling water supplied from the head side water jacket 31 side always flows in the merging portion 32 even when the second thermostat valve 70 is closed. It is difficult to itch. Thereby, the 2nd thermostat valve 70 can be made to react rapidly with respect to the change of the coolant temperature.

  The present invention is applicable to, for example, a cooling device for a water-cooled internal combustion engine.

10 Engine (Internal combustion engine)
20 Cylinder block 21 Block side water jacket 30 Cylinder head 31 Head side water jacket 32 Junction part 70 Thermostat valve 72 Temperature sensing part

Claims (4)

A block-side water jacket formed in the cylinder block;
A head-side water jacket formed in the cylinder head;
A cooling device for an internal combustion engine comprising: a valve that switches a circulation mode of the cooling water in the water jacket;
The cooling apparatus for an internal combustion engine, wherein the valve is provided in the cylinder head. The cooling apparatus for an internal combustion engine according to claim 1,
A cooling water circulation path for circulating cooling water in parallel to the block side water jacket and the head side water jacket;
A merging section for merging the cooling water that has passed through each of the water jackets,
The cooling apparatus for an internal combustion engine, wherein the merging portion is provided in the cylinder head. The cooling apparatus for an internal combustion engine according to claim 2,
The switching of the circulation mode of the cooling water in the water jacket includes a mode in which the cooling water is circulated in parallel to the block-side water jacket and the head-side water jacket, and the circulation of the cooling water in the block-side water jacket is stopped. , Switching to a mode of circulating the cooling water of the head side water jacket,
The valve is configured to switch the circulation mode of the cooling water by opening and closing an outlet flow path of the block-side water jacket according to a temperature of the cooling water flowing through the junction. Cooling device for internal combustion engine. The cooling apparatus for an internal combustion engine according to claim 3,
The said valve is a thermostat valve, The temperature sensing part is provided in the said junction part, The cooling device of the internal combustion engine characterized by the above-mentioned.

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