JP4875573B2 - Engine coolant passage structure - Google Patents

Description

  The present invention provides an integrated external device in which the downstream ends of a plurality of internal cooling water passages branched from a cooling water collecting portion formed in the engine main body are opened to the outer wall surface of the engine main body and coupled to the outer wall surface. The present invention relates to a cooling water passage structure for an engine in which a plurality of external cooling water passages whose upstream sides communicate with openings of the plurality of internal cooling water passages are formed inside a cooling water passage forming member.

A joint (external cooling water passage forming member) is fixed to the outer wall surface of the engine body, and the cooling water discharged from the water jacket provided inside the engine main body is passed through the external cooling water passage formation member to a radiator, a water pump, What is supplied to a heater core, a turbocharger, an EGR cooler, and the like is known from Patent Document 1 below.
JP 2002-349261 A

  By the way, in the above-mentioned conventional one, the water jacket provided inside the engine body and the external cooling water passage forming member fixed to the outer wall surface of the engine main body communicate with each other through a single opening. Since a plurality of cooling water passages branched from the cooling water collecting portion formed inside the forming member are connected to the radiator, water pump, heater core, turbocharger, EGR cooler, etc., the dimensions of the external cooling water passage forming member are There was a possibility that it would be difficult to lay out in a narrow engine room due to the increase in size.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to enable the supply of cooling water from the cooling water passage of the engine body to each auxiliary machine outside the engine with a compact structure.

In order to achieve the above object, according to the invention described in claim 1, the downstream ends of the plurality of internal cooling water passages branched from the cooling water collecting portion formed in the engine main body are the outer wall surfaces of the engine main body. And a plurality of external cooling water passages whose upstream sides communicate with the openings of the plurality of internal cooling water passages, respectively, in an integrated external cooling water passage forming member that is connected to the outer wall surface. And a downstream side of the first external cooling water passage communicating with the cooling water collecting portion at the highest position among the plurality of external cooling water passages communicates with the gas-liquid separator, and A cooling water passage structure for an engine is proposed, which is provided with an air venting device including an opening formed in the first external cooling water passage and a breathing bolt for closing the opening .

According to the invention described in claim 2, in addition to the first aspect, the first boss portion in which the breathing bolt is mounted is formed around the opening of the air vent device, before Kigaibu the cooling water passage structure for an engine in which the second boss portion for inserting a fixing member for fixing the coolant passage formation member to the outer wall surface of the engine body, characterized in that it is connected by the ribs is proposed.

  According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, a cooling water pump for circulating the cooling water is provided, and the downstream side of the plurality of external cooling water passages is always on the downstream side. A cooling water passage structure for an engine is proposed, wherein a cooling water temperature sensor is provided in a second external cooling water passage communicating with the suction side of the cooling water pump.

  According to the invention described in claim 4, in addition to the structure of claim 3, the radiator provided for cooling the cooling water and the cooling water passage communicating the radiator and the cooling water passage in the engine body are provided. A thermostat for controlling the flow of the cooling water in the cooling water passage, and the second external cooling water passage provided with the cooling water temperature sensor is connected to the cooling water pump regardless of whether the thermostat is opened or closed. A cooling water passage structure for an engine is proposed, which communicates with the intake side of the engine.

  According to the invention described in claim 5, in addition to the configuration of claim 3 or claim 4, the cooling water temperature sensor includes a main body exposed to the outside of the external cooling water passage forming member, A cooling water passage for an engine comprising: a temperature sensing portion housed inside an external cooling water passage forming member, wherein the temperature sensing portion is mounted so as to be positioned vertically above the main body portion. A structure is proposed.

The cylinder head 12 of the embodiment corresponds to the engine body of the present invention, and the first to third external cooling water passages 16 to 18 of the embodiment correspond to the external cooling water passage of the present invention. The expansion tank 19 corresponds to the gas-liquid separation device of the present invention, the water jacket 26 and the pipe P12 of the embodiment correspond to the cooling water passage of the present invention, and the bolt 31 of the embodiment corresponds to the fixing member of the present invention. corresponding, first to third internal coolant passages 34 to 36 of the embodiment you corresponds to the internal cooling water passage of the present invention.

According to the configuration of the first aspect, the downstream ends of the plurality of internal cooling water passages branched from the cooling water collecting portion formed in the engine main body are opened in the outer wall surface of the engine main body, and are integrally coupled to the outer wall surface. A plurality of external cooling water passages whose upstream sides communicate with the openings of the plurality of internal cooling water passages are formed inside the formed external cooling water passage forming member, and the cooling water collects among the plurality of external cooling water passages The first external cooling water passage communicating with the portion at the highest position is made to communicate with the gas-liquid separator, and includes an opening formed in the first external cooling water passage and a breathing bolt for closing the opening. Since the air venting device is provided, the external cooling water passage forming member has a cooling water collecting part inside, or compared with the case where a plurality of external cooling water passages are individually connected to the engine body. It is possible to increase the degree of freedom of layout path forming member is downsized. In addition, since it is lighter than the cooling water, not only can the air bubbles gathering upward be surely guided to the gas-liquid separation device via the first external cooling water passage located at a high position, but also the cooling water is supplied to the engine cooling system. By providing an air venting device in the first external cooling water passage where air bubbles tend to collect when the air is charged, the air venting device is effectively vented to completely fill the engine cooling system with the cooling water. Can do.

According to the second aspect, securing a first boss portion breathing bolt is mounted is formed around the opening of the air bleeding device, the external coolant passage formation member to the outer wall surface of the engine body fixed Having connected the second boss portion for inserting the member with ribs, it is possible to increase the rigidity of the external coolant passage formation member by the reinforcing effect of the ribs.

  According to the third aspect of the present invention, the cooling water pump that circulates the cooling water is provided, and the downstream side of the plurality of external cooling water passages is always cooled to the second external cooling water passage that communicates with the suction side of the cooling water pump. Since the water temperature sensor is provided, it is possible to detect the cooling water temperature with high accuracy by positioning the cooling water temperature sensor at a portion where the cooling water always flows.

  According to the configuration of claim 4, in addition to the configuration of claim 3, the coolant is provided in the cooling water passage that communicates the radiator and the cooling water passage in the engine body, and the circulation of the cooling water in the cooling water passage is performed. The second external cooling water passage with a thermostat to be controlled and provided with a cooling water temperature sensor communicates with the suction side of the cooling water pump regardless of the opening and closing state of the thermostat, so it is closed even when the thermostat is open Even in this case, it is possible to detect the cooling water temperature with high accuracy by positioning the cooling water temperature sensor in the portion where the cooling water always flows.

  According to the fifth aspect of the present invention, the cooling water temperature sensor includes a main body exposed to the outside of the external cooling water passage forming member, and a temperature sensing portion housed inside the external cooling water passage forming member. Since the temperature unit is attached so as to be positioned on the upper side in the vertical direction with respect to the main body, it is possible to avoid a situation in which bubbles are accumulated around the temperature sensing unit and the accurate temperature of the cooling water cannot be measured.

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

  1 to 6 show an embodiment of the present invention, FIG. 1 is a schematic view of an engine cooling system, and FIG. 2 is a view showing an outer wall surface of a cylinder head to which an external cooling water passage forming member is attached. 3 is a view taken in the direction of arrow 3 in FIG. 2, FIG. 4 is a view taken in the direction of arrow 4-4 in FIG. 3, FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. FIG.

  As shown in FIG. 1, the in-line four-cylinder engine includes an engine block 13 including a cylinder block 11 and a cylinder head 12, and one end side of the cylinder head 12 from a cooling water pump 14 provided on one end side of the engine block 13. Is supplied with cooling water. An external cooling water passage forming member 15, which will be described in detail later, is fixed to the other end side of the cylinder head 12, and cooling water is distributed in four directions via the external cooling water passage forming member 15.

  The external cooling water passage forming member 15 includes a first external cooling water passage 16, a second external cooling water passage 17, and a third external cooling water passage 18 independently of each other. The branch passage 17a branches from the middle.

  The first external cooling water passage 16 communicates with the upper part of the expansion tank 19 via the pipe P1, and the lower part of the expansion tank 19 communicates with the lower part of the radiator 20 via the pipe P2. The upper part of the radiator 20 also communicates with the upper part of the expansion tank 19 via the pipe P3. The second external cooling water passage 17 communicates with the turbocharger 21 via a pipe P4, and further communicates with the upper portion of the radiator 20 via a pipe P5. The third external cooling water passage 18 communicates with the heater core 22 via the pipe P6, further communicates with the thermostat 24 via the pipe P7, and further communicates with the suction side of the cooling water pump 14 via the pipe P8. A branch passage 17a branched from the second external cooling water passage 17 is connected to an intermediate portion of the pipe P7 connecting the heater core 22 and the thermostat 23 through the pipe P9, the breather riser 23, and the pipe P10.

  An oil cooler 25 is arranged so as to bypass the suction side and the discharge side of the cooling water pump 14. The water jacket 26 of the cylinder block 11 and the water jacket 27 of the cylinder head 12 communicate with each other. The water jacket 26 of the cylinder block 11 communicates with the upper portion of the radiator 20 through the pipe P11, and the thermostat 24 and the pipe P12 are connected. And communicates with the lower part of the radiator 20. A cooling water temperature sensor 28 is provided in the second external cooling water passage 17. Cooling fans 30 and 30 that are rotated by motors 29 and 29 are provided behind the radiator 20.

  Therefore, at a low temperature before the engine warm-up operation is completed, the valve body 24a of the thermostat 24 is in the raised position in FIG. 1, and the communication between the pipe P12 on the downstream side of the radiator 20 and the thermostat 24 is cut off. The water jacket 26 of the cylinder block 11 is connected to the pipe P8 on the upstream side of the cooling water pump 14. As a result, a closed circuit is formed to connect the water jacket 27 of the cylinder head 12 → the water jacket 26 of the cylinder block 11 → the thermostat 23 → the pipe P 8 → the cooling water pump 14 → the water jacket 27 of the cylinder head 12. The engine is warmed up by quickly increasing the temperature of the cooling water.

  On the other hand, at a high temperature after the engine warm-up operation is completed, the valve body 24a of the thermostat 24 is in the lowered position in FIG. 1, and the pipe P12 on the downstream side of the radiator 20 is connected to the pipe P8 on the upstream side of the cooling water pump 14. And the water jacket 26 of the cylinder block 11 is shut off from the pipe P8 on the upstream side of the cooling water pump 14. As a result, the closed circuit connecting the water jacket 27 of the cylinder head 12 → the water jacket 26 of the cylinder block 11 → the pipe P 11 → the radiator 20 → the pipe P 12 → the thermostat 24 → the pipe P 8 → the cooling water pump 14 → the water jacket 27 of the cylinder head 12. As the cooling water passes through the radiator 20, the temperature of the cooling water can be lowered to prevent the engine from overheating.

  Further, the cooling water discharged from the water jacket 27 of the cylinder head 12 is supplied to the third cooling water passage 18 of the external cooling water passage forming member 15 → pipe P6 → heater core 22 → pipe P7 → thermostat 24 → pipe P8 → cooling water pump 14 → The passenger compartment can be heated by flowing through a closed circuit connecting the water jacket 27 of the cylinder head 12 and exchanging heat with the air by the heater core 22.

  Further, the cooling water discharged from the water jacket 27 of the cylinder head 12 is supplied to the radiator 20 through the second cooling water passage 17 → pipe P4 → turbocharger 21 → pipe P5 of the external cooling water passage forming member 15. Then, the turbocharger 21 is cooled. The cooling water branched from the second cooling water passage 17 communicates with the intermediate portion of the pipe P7 through the branch passage 17a → the pipe P9 → the breather riser 23 → the pipe P10, and the breather riser 23 warms the breather during that time. To do.

  Further, the cooling water discharged from the water jacket 27 of the cylinder head 12 is supplied from the first cooling water passage 16 of the external cooling water passage forming member 15 to the expansion tank 19 via the pipe P 1, and the cooling water discharged from the radiator 20. Is supplied to the expansion tank 19 through the pipe P3, and the cooling water from which the bubbles are separated is returned to the radiator 20 through the pipe P2.

  Further, the cooling water flows through the oil cooler 25 due to the pressure difference between the front and rear of the cooling water pump 14, whereby the oil is cooled in the oil cooler 25.

  Next, the structure of the external cooling water passage forming member 15 will be described in detail with reference to FIGS.

  As is apparent from FIGS. 2 to 4, the cylinder head 12 includes a flat lower surface 12 a coupled to the cylinder block 11 and a flat upper surface 12 b coupled to a head cover (not shown). The cylinder axis L perpendicular to 12a and the upper surface 12b is inclined with respect to the horizontal plane H by an angle θ. A flat seat surface 12d is formed on the outer wall surface 12c on the other end side with respect to the coolant supply side of the cylinder head 12, and the flat mounting surface 15a of the external coolant passage forming member 15 is formed on the seat surface 12d. And are fixed by three bolts 31, 32, 33.

  A cooling water collecting portion 12e located at the downstream end of the water jacket 27 is formed inside the cylinder head 12 facing the external cooling water passage forming member 15, and the cooling water collecting portion 12e is directed to the seat surface 12d. The short first to third internal cooling water passages 34, 35, 36 penetrate independently.

  The first to third external cooling water passages 16, 17, 18 are opened on the mounting surface 15 a of the external cooling water passage forming member 15, and the first internal cooling water passage 34 is connected to the first external cooling water passage 16. The second internal cooling water passage 35 communicates with the second external cooling water passage 17, and the third internal cooling water passage 36 communicates with the third external cooling water passage 18. A sealing member 37 is disposed on the mounting surface 15 a of the external cooling water passage forming member 15 so as to surround the first to third external cooling water passages 16, 17 and 18.

  As apparent from FIGS. 2, 3, and 5, among the first to third external cooling water passages 16, 17, and 18 of the external cooling water passage forming member 15, the first external cooling water passage 16 is the cylinder head 12. The cooling water collecting portion 12e communicates with the highest position, and the height gradually increases from the upstream side toward the downstream side. A first boss portion 15 b is formed around an opening 38 that branches upward from an intermediate portion of the first external cooling water passage 16, and a breathing bolt 39 is screwed into the opening 38.

  The opening 38 has a small diameter portion 38a, a large diameter portion 38b, and a female screw portion 38c in this order from the bottom to the top. The breathing bolt 39 has a small-diameter portion 39a, a male screw portion 39b, and a hexagonal portion 39c in this order from the bottom to the top. A breathing hole 39e opens in the small diameter portion 39a.

  Of the three bolts 31, 32, 33 for fixing the external cooling water passage forming member 15 to the cylinder head 12, a portion through which one bolt 31 closest to the first boss portion 15b to which the breathing bolt 39 is screwed passes. A second boss portion 15c is formed on the first boss portion 15c, and the first boss portion 15b and the second boss portion 15c are connected by a rib 15d.

  Thus, the first boss portion 15b for mounting the breathing bolt 39 and the second boss portion 15c for mounting the bolt 31 for fixing the external cooling water passage forming member 15 to the cylinder head 12 are connected by the rib 15d. The rigidity of the external coolant passage forming member 15 can be increased by the reinforcing effect of the ribs 15d.

  As apparent from FIGS. 2, 4 and 6, a third boss portion 15 e protrudes obliquely downward from an intermediate portion of the second external cooling water passage 17 of the external cooling water passage forming member 15. The main body 28a of the cooling water temperature sensor 28 is screwed into the opening 15f of the three boss 15e. A temperature sensing portion 28 b that protrudes obliquely upward from the main body portion 28 a of the cooling water temperature sensor 28 extends into the second external cooling water passage 17.

  As described above, the cooling water temperature sensor 28 is configured such that the temperature sensing portion 28b housed inside the external cooling water passage forming member 15 is vertically above the main body portion 28a exposed to the outside of the external cooling water passage forming member 15. Therefore, it is possible to avoid a situation in which bubbles are accumulated around the temperature sensing portion 28b and the accurate temperature of the cooling water cannot be measured.

  When the cooling system is filled with the cooling water at the time of factory shipment of the engine, the cap of the expansion tank 19 at the highest position of the cooling system is removed and the cooling water is injected. At this time, in FIG. 5, if the breathing bolt 39 provided in the first external cooling water passage 16 of the external cooling water passage forming member 15 is loosened, the small diameter portion 39 a is shifted upward from the large diameter portion 38 b of the opening 38. Therefore, the second external cooling water passage 16 communicates with the atmosphere through the small diameter portion 38a and the large diameter portion 38b of the opening 38, the second breathing hole 39e and the first breathing hole 39d of the breathing bolt 39. Thereby, the air in a cooling system can be discharged | emitted to air | atmosphere, and cooling water can be supplied smoothly.

  As apparent from FIG. 2, the breathing bolt 39 is disposed at the highest position of the inclined cylinder head 12, that is, at the highest position of the cooling system of the engine body, and therefore when the cooling water overflows from the breathing bolt 39. It is confirmed that the cooling water has spread throughout the cooling system of the engine body. Therefore, by tightening the breathing bolt 39 in this state, the supply of cooling water to the cooling system of the engine body can be completed with certainty.

  Further, since the external cooling water passage forming member 15 does not have a cooling water collecting portion, not only can the external cooling water passage forming member be miniaturized to increase the degree of freedom of layout, but also the inside of the external cooling water passage forming member 15 can be Since the 1st-3rd external cooling water passages 16-18 were provided, space efficiency can further be improved compared with the case where they are provided separately. Moreover, since the first external cooling water passage 16 located at a higher position in the external cooling water passage forming member 15 communicates with the expansion tank 19, bubbles generated in the engine can be reliably guided to the expansion tank 19.

  Further, a second downstream side of the first to third external cooling water passages 16 to 18 always communicates with the suction side of the cooling water pump 14 via the branch passage 17a (regardless of whether the thermostat 24 is opened or closed). Since the cooling water temperature sensor 28 is provided in the external cooling water passage 17, the cooling water temperature sensor 28 can be positioned at a portion where the cooling water always flows, and the cooling water temperature can be detected with high accuracy.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, although the external cooling water passage forming member 15 of the embodiment includes the first to third external cooling water passages 16, 17, and 18, the number of external cooling water passages is not limited to three. .

  Further, the thermostat 24 of the embodiment is provided in a cooling water passage that connects the inlet of the engine main body and the outlet of the radiator 20 (inlet control). The thermostat 24 includes the outlet of the engine main body and the radiator 20. It may be provided in a cooling water passage communicating with the inlet (exit control).

Schematic diagram of engine cooling system The figure which shows the outer wall surface of the cylinder head with which the external cooling water channel | path formation member was mounted | worn 3 direction arrow view of FIG. 4-4 arrow view of FIG. Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG.

12 Cylinder head (engine body)
12c outer wall surface 12e cooling water collecting portion 14 cooling water pump 15 external cooling water passage forming member 15b first boss portion 15c second boss portion 15d rib 16 first external cooling water passage (external cooling water passage)
17 Second external cooling water passage (external cooling water passage)
18 Third external cooling water passage (external cooling water passage)
19 Expansion tank (gas-liquid separator)
20 Radiator 24 Thermostat 28 Cooling Water Temperature Sensor 28a Main Body 28b Temperature Sensing Unit 31 Bolt (Fixing Member)
34 First internal cooling water passage (internal cooling water passage)
35 Second internal cooling water passage (internal cooling water passage)
36 Third internal cooling water passage (internal cooling water passage)
38 opening 39 breathing bolt 40 air bleeding device

Claims (5)

The downstream ends of the plurality of internal cooling water passages (34, 35, 36) branched from the cooling water collecting portion (12e) formed in the engine body (12) are connected to the outer wall surface (12c) of the engine body (12). Opened and integrated with the external cooling water passage forming member (15) connected to the outer wall surface (12c), and the upstream side is the opening of the plurality of internal cooling water passages (34, 35, 36). A cooling water passage structure for an engine having a plurality of external cooling water passages (16, 17, 18) communicating with each other,
Of the plurality of external cooling water passages (16, 17, 18), the gas-liquid separator (19) is located downstream of the first external cooling water passage (16) communicating with the cooling water collecting portion (12e) at the highest position. ) And an air venting device (40) comprising an opening (38) formed in the first external cooling water passage (16) and a breathing bolt (39) for closing the opening (38). A cooling water passage structure for an engine. Wherein formed around the first boss portion breathing bolt (39) is mounted and (15b), before Kigaibu coolant passage formation member (15) of the opening (38) of the air vent device (40) The second boss portion (15c) that is inserted through a fixing member (31) that is fixed to the outer wall surface (12c) of the engine body (12) is connected by a rib (15d). Engine coolant passage structure.   A cooling water pump (14) for circulating cooling water is provided, and a second outer side in which the downstream side of the plurality of external cooling water passages (16, 17, 18) always communicates with the suction side of the cooling water pump (14). The cooling water passage structure for an engine according to claim 1 or 2, characterized in that a cooling water temperature sensor (28) is provided in the cooling water passage (17).   A radiator (20) that cools the cooling water, and a cooling water passage (P12) that connects the radiator (20) and the cooling water passage (26) in the engine body (12) to the cooling water passage (P12). ) And the second external cooling water passage (17) provided with the cooling water temperature sensor (28) is in an open / closed state of the thermostat (24). 4. The engine coolant passage structure according to claim 3, wherein the coolant passage communicates with the suction side of the coolant pump (14).   The cooling water temperature sensor (28) includes a main body (28a) exposed to the outside of the external cooling water passage forming member (15), and a temperature sensitive accommodated in the external cooling water passage forming member (15). The temperature sensor (28b) is attached so that it may be located in the vertical direction upper side with respect to the main-body part (28a). Engine coolant passage structure.

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