INTERNAL COMBUSTION ENGINE COOLANT PASSAGE SYSTEM

Abstract: A coolant passage system in a V-shaped internal combustion engine includes a coolant pump (4) disposed on one side of the engine in the direction of the crankshaft (l8), at the V-shaped space between the cylinder banks (2), for delivering a coolant into coolant jackets (3) defined respectively in the cylinder banks, the coolant pump having an inlet opening toward the V-­ shaped space. A collecting conduit (5) is disposed on an opposite side of the engine at the V-shaped space for delivering the coolant from the coolant jackets to a radiator(6). A valve casing (8) housing a thermovalve (7) therein for delivering the coolant from said radiator is integrally formed with the collecting conduit and has an outlet (a) opening toward the V-shaped space. The inlet of the coolant pump and the outlet of the collecting conduit are interconnected by a connecting pipe (9) disposed in the V-­ shaped space.

Description: The present invention relates to an internal combustion engine, and more particularly to a coolant pas­ sage system in a V-shaped internal combustion engine. One known coolant passage system in a V-shaped internal combustion engine comprises a coolant pump for delivering the coolant into coolant jackets defined respectively in a pair of cylinder banks of the engine, and a collecting conduit for supplying the coolant from the coolant jackets to a radiator, as disclosed in Japanese Laid-Open Patent Publication No. 58(l983)-l07840. In that system the coolant pump and the conduit are disposed on one side of the cylinder banks in the direction of the crankshaft. However, with the coolant pump and the conduit being thus positioned on one side of the banks, that side of the bank is crowded with components, which cannot easily be serviced. U.S. Patent No. 2,807,245 to Unger also discloses a conventional cooling system for an engine wherein the coolant is used for heating the intake manifold. Viewed from one aspect the present invention provides a coolant passage system in a V-shaped internal combustion engine having a crankshaft, a radiator, and a pair of cylinder banks having respective coolant jackets defined therein, with a V-shaped space defined between said cylinder banks, comprising: a coolant pump disposed on one side of said cylinder banks in the direction of said crankshaft for delivering a coolant into said coolant jackets, said coolant pump having an inlet opening toward said V-shaped space; a collecting conduit disposed on an opposite side of said cylinder banks for delivering the coolant from said coolant jackets to said radiator; a valve casing housing a thermovalve for delivering the coolant from said radiator, said valve casing being integrally formed with said collecting conduit and having an outlet opening toward said V-shaped space; and a connecting pipe interconnecting said inlet and said outlet and disposed in said V-shaped space. Viewed from another aspect the invention provides a coolant passage system in a V-shaped internal combustion engine having a crankshaft, a radiator and a pair of cylinder banks having respective coolant jackets defined therein, comprising: a collecting conduit disposed on one side of said cylinder banks in the direction of the crankshaft and having an outlet for delivering the coolant from said coolant jackets to said radiator; and a valve casing housing a thermovalve substantially horizontally therein for delivering the coolant from said radiator, said valve casing being integrally formed with said collecting conduit adjacent to said outlet of said collecting conduit and having an open outer end for receiving the coolant from said radiator, said valve casing having a bypass port de­ fined in a side wall between said valve casing and said collecting conduit, an outlet port defined in a lower side wall of said valve casing, and an outlet extending inwardly from said outlet port beneath said collecting conduit. An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Fig. l is a schematic plan view of a V-shaped internal combustion engine incorporating a coolant pas­ sage system according to the present invention; Fig. 2 is a plan view of the engine; Fig. 3 is a left-hand side elevational view, partly broken away, of the engine; Fig. 4 is a right-hand side elevational view of the engine; Fig. 5 is an enlarged plan view of a collecting conduit of the coolant passage system; Fig. 6 is a right-hand side elevational view of the collecting conduit shown in Fig. 5; Fig. 7 is a cross-sectional view taken along line VII - VII of Fig. 5; and Fig. 8 is a cross-sectional view taken along line VIII - VIII of Fig. 5. As shown in Fig. l, a V-shaped internal combustion engine for use on an automobile and designed to be mounted transversely of the automobile includes a pair of front and rear cylinder banks 2 inclined to each other in the form of a V, each of the cylinder banks 2 having a coolant jacket 3 defined therein. An engine coolant is supplied by a common coolant pump 4 into the coolant jackets 3 of both banks through respective inlets 3a. The engine coolant which has been heated in the coolant jackets 3 is then delivered from the coolant jackets 3 through respective outlets 3b into a collecting conduit 5 connected thereto, and then supplied from the collecting conduit 5 into a radiator 6 disposed in front of the engine l. The engine coolant that has been cooled by the radiator 6 is delivered from the radiator 6 through a thermostatical controlled valve or thermovalve 7, which is positioned downstream of the radiator 6, into the coolant pump 5 via its inlet 4a which opens toward the V-shaped space l9 between the cylinder banks 2. The engine coolant is therefore forcibly circulated by the coolant pump 4 through the engine coolant passage system. The coolant pump 4 is disposed on one side of the engine l in the direction of a crankshaft l8 (Fig. 3), while the collecting conduit 5 is disposed on the opposite side of the engine l. The thermovalve 7 is housed in a valve casing 8 integrally formed with the collecting conduit 5. The valve casing 8 has an outlet 8a opening toward the V-shaped space l9 and connected to the inlet 4a of the coolant pump 4 through a connecting pipe 9 disposed in the V-shaped space l9 and extending parallel to the cylinder banks 2. As illustrated in Figs. l through 3, the coolant pump 4 is in the form of a centrifugal pump having a pump casing 4c in which an impeller 4b is rotatably housed. The pump casing 4c has a pair of outlets 4d defined in opposite ends thereof which communicate with the inlets 3a, respec­ tively, of the coolant jackets 3. The inlet 4a of the coolant pump 4 is located centrally in a side of the pump casing 4c. The coolant pump 4 is positioned on one side of the cylinder banks 2 where a timing belt l0 is located, i.e., on the left-hand side of Fig. 2, whereas the collecting conduit 5 is disposed on the opposite side of the cylinder banks 2 where a transmission case (not shown) is located i.,e, on the right-hand side of Fig. 2. The connecting pipe 9 lying in the V-shaped space l9 has one end fitted in the inlet 4a and the opposite end fitted in the outlet 8a. As shown in Figs. 4 through 6, the collecting conduit 5 has an outlet 5a extending laterally outwardly from a coolant passage portion 5b which extends between the cylinder banks 2 and interconnects the outlets 3b. The outlet 5a opens forwardly toward the radiator. The valve casing 8 is disposed adjacent to the outlet 5a and has an open lateral outer end for receiving the coolant from the radiator 6. The outlet 8a of the casing 8 extends laterally inwardly from a lower side of the casing 8 beneath the coolant pas­ sage portion 5b into communication with the connecting pipe 9. The thermovalve 7 is housed horizontally in the valve casing 8. As shown in Figs. 7 and 8, the thermovalve 7 comprises a first valve body 7a movably positioned in confronting relation to a bypass port 8b defined in a side wall 8c positioned between the coolant passage portion 5b and the valve casing 8, a second valve body 7d movably positioned in confronting relation to an inlet port 7c defined in a valve seat 7b fitted in the valve casing 8, the inlet port 7c communicating with the radiator 6, and a temperature sensor 7e on which the first and second valve bodies 7a, 7d are mounted. The temperature sensor 7e is horizontally disposed in the valve casing 8 and supported on the valve seat 7b by a piston rod 7f having one end inserted in the temperature sensor 7e and an opposite end attached to a bracket 7h fixed to the valve seat 7b. The valve seat 7b is retained in position on the valve casing 8 by a cap ll attached to the valve casing 8 and having a connecting port lla communicating with the radiator 6. The valve casing 8 has an outlet port 8d defined in a lower side wall 8e of the valve casing 8 and communicating with the oulet 8a, which extends inwardly from the outlet port 8d. The second valve body 7d is normally urged in a direction to close the inlet port 7c by a spring 7g disposed around the temperature sensor 7e and acting between the second valve body 7d and a bracket 7i attached to the valve seat 7b remotely from the bracket 7h. The thermovalve 7 functions in a conventional manner. During engine warm-up or any other condition when the coolant is at a low temperature, the valve body 7d closes inlet port 7c to prevent coolant from being drawn from the radiator 6 and the valve body 7a is open to cause the coolant to be recirculated through the engine. When the coolant is at or above a selected temperature, the valve body 7a closes and the valve body 7d opens to allow coolant to be drawn from the radiator. A valve l2 known as a jiggle pin is mounted in the side wall 8c for bleeding air out of the valve casing 8. As shown in Fig. l, the outlet 5a of the col­ lecting conduit 5 is connected by a hose l3 to the radiator 6. The connecting port lla of the cap ll is connected by a hose l4 to the radiator 6. As shown in Figs. 2 and 3, the timing belt l0 is covered by a belt cover l5. The timing belt l0 is trained around a pulley 20 mounted on the crankshaft l8, a pair of pulleys 2l mounted on camshafts 22 rotatably supported by the cylinder banks 2, respectively, and a pulley l6 coupled to the coolant pump 4b. As shown in Figs. 2 and 4, an intake manifold l7 is positioned in the V-­ shaped space l9 and above the connecting pipe 9. Operation of the coolant passage system as thus constructed is as follows: When the coolant pump 4 is operated, the coolant is delivered from the inlets 3a into the coolant jackets 3. The coolant as it is heated is delivered from the coolant jackets 3 into the collecting conduit 5, from which the coolant is fed through the outlet 5a and the hose l3 into the radiator 6, in which the coolant is cooled. Then, the coolant is fed through the hose l4, the thermovalve 7 in the valve casing 8, the outlet 8a, and the connecting pipe 9 into the inlet 4a of the coolant pump 4. The coolant is therefore forcibly circulated through the coolant passage system by the coolant pump 4. The outlet 8a of the valve casing 8 extends across and beneath the collecting tube 5 for supplying the coolant from the radiator 6 to the connecting pipe 9 coupled to the inlet 4a of the coolant pump 4. The valve casing 8 that houses the thermovalve 7 is integrally formed with the collecting conduit 5, with the outlet 8a opening toward the V-shaped space l9. This tubing arrangement is relatively compact and small in size. Since the coolant pump 4 is disposed on one side of the cylinder banks 2 and the collecting conduit 5 is on the other side, with the connecting pipe 9 between the coolant pump 4 and the collecting conduit 5 being disposed in the V-shaped space l9. neither side of the cylinder banks 2 is crowded with components. As a result, the entire coolant passage system is relatively simple and compact, and can easily be serviced. Inasmuch as the valve casing 8 is integral with the collecting conduit 5, the number of components required is reduced, and also the number of parts to be sealed is small. It is to be clearly understood that there are no particular features of the foregoing specification, or of any claims appended hereto, which are at present regarded as being essential to the performance of the present invention, and that any one or more of such features or combinations thereof may therefore be included in, added to, omitted from or deleted from any of such claims if and when amended during the prosecution of this application or in the filing or prosecution of any divisional application based thereon.

Claims: 1. A coolant passage system in a V-shaped internal combustion engine having a crankshaft, a radiator, and a pair of cylinder banks having respective coolant jackets defined therein, with a V-shaped space defined between said cylinder banks, comprising: a coolant pump disposed on one side of said cylinder banks in the direction of said crankshaft for delivering a coolant into said coolant jackets, said coolant pump having an inlet opening toward said V-shaped space; a collecting conduit disposed on an opposite side of said cylinder banks for delivering the coolant from said coolant jackets to said radiator; a valve casing housing a thermovalve for delivering the coolant from said radiator, said valve casing being integrally formed with said collecting conduit and having an outlet opening toward said V-shaped space; and a connecting pipe interconnecting said inlet and said outlet and disposed in said V-shaped space. 2. A coolant passage system according to claim l, wherein said coolant pump comprises a pump casing and an impeller rotatably disposed in said pump casing, said pump casing having a pair of outlets communicating with said coolant jackets, respectively. 3. A coolant passage system according to claim 2, wherein said outlets of said pump casing are defined respectively at opposite ends thereof, said inlet of said pump casing being positioned between said outlets. 4. A coolant passage system according to any of claims l to 3, wherein said collecting conduit has a coolant passage portion extending between said cylinder banks and communicating with said coolant jackets, and an outlet extending from said coolant passage portion and communicating with said radiator, said outlet of said valve casing extending across said coolant passage portion. 5. A coolant passage system according to any preceding claim, wherein said connecting pipe extends parallel to said cylinder banks and has opposite ends fitted in said inlet and said outlet, respectively. 6. A coolant passage system according to any preceding claim, wherein said collecting conduit has an outlet for delivering the coolant to said radiator, said thermovalve being housed substantially horizontally in said valve casing, said valve casing being disposed adjacent to said outlet of said collecting conduit and having an open outer end for receiving the coolant from said radiator, said valve casing having a bypass port defined in a side wall between said valve casing and said collecting con­ duit, and an outlet port defined in a lower side wall of said valve casing, said outlet of the valve casing extending inwardly from said outlet port beneath said collecting conduit into communication with said connecting pipe. 7. A coolant passage system according to claim 6 wherein said thermovalve has means for opening said bypass port during low coolant temperature conditions and closing said bypass port during high coolant temperature conditions. 8. A coolant passage system in a V-shaped internal combustion engine having a crankshaft, a radiator and a pair of cylinder banks having respective coolant jackets defined therein, comprising: a collecting conduit disposed on one side of said cylinder banks in the direction of the crankshaft and having an outlet for delivering the coolant from said coolant jackets to said radiator; and a valve casing housing a thermovalve substantially horizontally therein for delivering the coolant from said radiator, said valve casing being integrally formed with said collecting conduit adjacent to said outlet of said collecting conduit and having an open outer end for receiving the coolant from said radiator, said valve casing having a bypass port de­ fined in a side wall between said valve casing and said collecting conduit, an outlet port defined in a lower side wall of said valve casing, and an outlet extending inwardly from said outlet port beneath said collecting conduit. 9. A coolant passage system according to claim 8 wherein a coolant pump is disposed on an opposite side of said cylinder banks in the direction of the crankshaft, and means extending along and between said cylinder banks connects said coolant pump to said outlet from the valve casing. l0. A coolant passage system according to claim 8 or 9, wherein a thermovalve is provided and has means for opening said bypass port during low coolant temperature conditions and closing said bypass port during high coolant temperature conditions.

Inventors: KOINUMA, YUTAKA KABUSHIKI KAISHA HONDA
Applicants: HONDA GIKEN KOGYO KABUSHIKI KAISHA
Application year: 1986
Main classification: F02B75
IPC codes: F01P11, F01P7, F02B75, F01P5, F02B67, F01P3