JP4566073B2 - Cooling device for internal combustion engine - Google Patents

Description

  The present invention relates to a cooling device for an internal combustion engine, and more particularly to a cooling device for an internal combustion engine characterized by an improvement in a cooling water supply structure.

In an internal combustion engine cooling apparatus including an oil cooler that cools lubricating oil of an internal combustion engine with cooling water, as a cooling water supply structure, a branch cooling water to an oil cooler is provided in a main cooling water passage from a water pump to an internal combustion engine cooling unit. One with a passage is known. In the cooling water supply structure of the cooling device, the cooling water supplied to the oil cooler is returned to the water pump via the radiator even when the cooling water temperature is low, such as when the internal combustion engine is started. Yes. As another cooling water supply structure, an oil cooler is installed directly on the main cooling water passage from the water pump to the internal combustion engine cooling section, and the total amount of cooling water supplied to the internal combustion engine cooling section is oil. A technique for passing through a cooler is also known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-189264 (pages 2 to 3, FIGS. 2 and 9)

  The cooling device for an internal combustion engine described in Patent Document 1 includes the above-described cooling water supply structure. However, in this cooling water supply structure, even when the cooling water temperature during the warm-up operation at the start of the internal combustion engine is low. Since the cooling water that passes through the oil cooler passes through the radiator, the rise in the cooling water temperature is suppressed and the engine is not easily warmed due to the circulation of the cooling water having a low water temperature, and the warm-up operation time is increased accordingly. End up. Further, when the oil cooler is directly installed in the middle of the main cooling water passage in the cooling water supply to the engine, the entire amount of the cooling water supplied to the engine passes through the cooling part of the oil cooler, As a result, the capacity of the oil cooler increases more than necessary.

  For this reason, during the warm-up operation of the internal combustion engine, the cooling water is circulated without passing through the radiator so as to improve the warm-up characteristic of the internal combustion engine, and after the warm-up operation, via the radiator A cooling device for an internal combustion engine in which high cooling efficiency is stably ensured by circulation of the cooled cooling water.

The present invention relates to the provision of a cooling device for an internal combustion engine for solving the above-described problems, and includes a water pump that discharges cooling water, a cooling unit for the internal combustion engine that cools the internal combustion engine with the cooling water, and the cooling water. Select a lubricating oil cooling section for cooling the lubricating oil, a radiator for cooling the cooling water, a plurality of cooling water flow paths that communicate with each other for the flow of cooling water, and a cooling water flow path at a predetermined temperature. In the cooling device for an internal combustion engine provided with a thermostat that switches automatically, the cooling water flow path is configured such that the cooling water is discharged from the water pump and passes through the cooling portion of the internal combustion engine, a radiator, and a thermostud in this order. A main cooling path that is recirculated, a bypass path that is connected downstream of the cooling section of the internal combustion engine and to the thermostat so as to bypass the radiator, Part is connected between the cooling section of the water pump engine on the upstream side main cooling path path through consists of a lubricating oil cooling path downstream side is connected to the upper tank of the radiator, the thermostat, the main cooling A cooling device for an internal combustion engine, which is arranged to selectively switch these paths at the predetermined temperature to a portion where a thermostat upstream path of the bypass path is connected to a path downstream of a radiator of the path. .

The thermostat case that houses the thermostat is formed integrally with the case of the water pump.
Furthermore, a thermostat case for accommodating the thermostat is formed integrally with the radiator structure.
The thermostat case for accommodating the thermostat is disposed on a cooling water passage connecting the radiator and the water pump.

  According to a first aspect of the present invention, in the cooling device for an internal combustion engine described above, the cooling water flow path is such that the cooling water is discharged from the water pump and passes in the order of the cooling portion of the internal combustion engine, the radiator, and the thermostat. The main cooling path that is recirculated to the water pump, the bypass path connected to the cooling section of the internal combustion engine and the thermostat so as to bypass the radiator, and the upstream side of the path that passes through the lubricating oil cooling section are main. It is connected between the water pump of the cooling path and the cooling part of the internal combustion engine, and the downstream side is between the cooling part of the internal combustion engine of the main cooling path and the upstream of the radiator, or between the cooling part of the internal combustion engine of the main cooling path and the thermostat of the bypass path The thermostat is connected to the radiator downstream path of the main cooling path and the bypass path Cooling water provided for cooling the engine cooling unit and the lubricating oil cooling unit during warm-up operation because the thermostat upstream path is connected to the portion where the upstream path is connected to selectively switch the paths at the predetermined temperature. Is recirculated to the water pump without passing through the radiator, so that it is possible to improve the warm-up characteristics during the warm-up operation, without increasing the capacity of the oil cooler in cooling the lubricating oil. The maximum utilization of the cooling efficiency of the cooler is achieved. In addition, after the warm-up operation, all the cooling water used for cooling the engine cooling unit and the lubricating oil cooling unit is circulated to the water pump via the radiator and circulated, ensuring high cooling performance stably. Is done.

  According to a second aspect of the present invention, in the first aspect of the present invention, since the thermostat case that houses the thermostat is formed integrally with the case of the water pump, the thermostat case and the water pump Integration with the case reduces the number of parts and saves space. Moreover, since piping downstream of the gathering portion is not necessary, the piping length can be shortened and the weight can be reduced.

  According to a third aspect of the present invention, in the first aspect of the present invention, since the thermostat case that houses the thermostat is formed integrally with the radiator structure, the thermostat case and the radiator structure Integration with the unit reduces the number of parts and saves space. Moreover, since the length of the bypass passage can be shortened, the weight can be reduced.

  Furthermore, in the invention according to claim 4 of the present invention, in the invention according to claim 1, the thermostat case that accommodates the thermostat is disposed on a cooling water passage that connects the radiator and the water pump. The thermostat is formed separately from the radiator and the water pump, and the thermostat and its case can be used as a common part for a plurality of models, so the cost can be reduced. Moreover, since the fixing position of the thermostat can be arranged at an arbitrary position, that is, at a position corresponding to the shape of the internal combustion engine or the vehicle, versatility can be improved.

  The embodiment of the present invention illustrated in FIGS. 1 to 6-3 will be described below.

  FIG. 1 is a side view of a motorcycle equipped with a water-cooled in-line four-cylinder internal combustion engine to which an embodiment of the present invention is applied, partially shown in cross section. A body frame 10 of the motorcycle includes a plurality of frame members. An internal combustion engine E in which a transmission M is integrated is suspended from a main frame 11 connected to the head pipe 12, and a front fork 13 is suspended from the head pipe 12. A steering handle 14 is attached to the upper end of the steering wheel 14, and a front wheel Wf is pivotally supported on the lower end.

  A rear fork 15 is pivotally supported at the rear portion of the main frame 11 by pivotally supporting the front end thereof. A rear cushion is interposed between the rear fork 15 and the main frame 11 via a triangular link member 16. 17 is interposed. A rear wheel Wr is pivotally supported at the rear end of the rear fork 15. The rear wheel Wr is wound between a drive sprocket (not shown) mounted on a shaft end (described later) of the transmission unit M of the internal combustion engine E and a driven sprocket 18 mounted on the shaft of the rear wheel Wr. It is driven by a chain 19 that is hung.

  A fuel tank 20 is mounted on the upper part of the main frame 11 of the vehicle body, and a seat S for a rider is mounted behind the fuel tank 20. As described above, the internal combustion engine E is a water-cooled engine. For this purpose, the internal combustion engine E is equipped with a radiator R for cooling the cooling water whose temperature has been raised in the course of cooling the cylinder and the lubricating oil.

  As can be understood by referring to FIG. 3-1, etc., the radiator R is a round type whose front side is curved in a concave shape, and the cylinder portion of the engine E is disposed on the front side of the internal combustion engine E as shown in FIG. The upper tank R1, which is a cooling water inflow tank, is disposed on the right side of the radiator core R3 when viewed in the traveling direction, and the lower tank, which is an outflow side tank, is disposed on the left side. R2 is a cross-flow type, and the vertical direction of the radiator R reaches just from the upper part of the cylinder part of the engine E to the lower part of the crankcase 1, and the radiator fan is located on the upper back side of the radiator core R3. R4 is attached, and a sub-tank R5 for returning the steam to water via an overflow pipe is attached to the upper part of the upper tank R1.

Here, the outline of the structure of the internal combustion engine E equipped with the cooling device of the present invention will be described.
As described above, the internal combustion engine E of the present invention is a water-cooled in-line four-cylinder engine. As shown in FIG. 2, the internal combustion engine E of the present invention is divided into an upper crankcase 1A and a lower crankcase which are divided into upper and lower parts. A crankcase 1 made of 1B, a cylinder block 2 formed integrally with the case 1A above the upper crankcase 1A, a cylinder head 3 mounted on the cylinder block 2, and a head cover that covers the cylinder head 3 4 is provided.

  A crankshaft 1a is rotatably supported by the crankcase 1 and a piston P is attached to a crankpin 1b of the crankshaft 1a via a connecting rod 1c. The piston P is disposed in a cylinder bore 2a of a cylinder block 2 described later. Sliding up and down. Further, the crankcase 1 is provided with a main shaft 1d and a countershaft 1e that are arranged in parallel with the crankshaft 1a constituting the transmission portion M.

  The main shaft 1d and the counter shaft 1e are equipped with a gear mechanism G composed of a plurality of transmission gears that can be engaged with each other as desired, and the drive gear 1a1 at the end of the crankshaft 1a and the driven gear 1d1 of the main shaft 1d are engaged. Further, the rotation of the crankshaft 1 transmitted through the opening and closing of the switching clutch 1d2 on the main shaft 1d is shifted by the transmission unit M, and as described above, the driving wheel is driven by chain transmission from the driving sprocket (not shown). It is transmitted to the rear wheel Wr.

  The cylinder block 2 integrally formed with the upper crankcase 1A is provided with the cylinder bore 2a as described above, and the upper portion of the cylinder bore 2a is coupled with the lower portion of the cylinder head 3 to form a combustion chamber 3a. The piston P described above is pushed down in response to the combustion energy in 3a, and the crankshaft 1a is rotationally driven by sliding in the cylinder bore 2a.

  The cylinder head 3 is formed with the above-described combustion chamber 3a at the bottom, and an ignition plug (not shown) is attached to the combustion chamber 3a, and an opening 3b for intake and exhaust is provided. An intake / exhaust valve 3c is disposed in the opening 3b for exhaust. Further, a cam shaft 3e provided with a cam 3d for opening and closing the intake / exhaust valve 3c is provided on the upper portion of the cylinder head 3. A head cover 4 is attached to the cylinder head 3 so as to cover the cam shaft 3e and the like above the cylinder head 3.

  An oil pan 1C is attached below the lower crankcase 1B, and an oil pump Op is disposed at the upper portion of the oil pan 1C and opposite the oil pan 1C. A drive sprocket 1d3 provided on the shaft 1d is driven via a chain 1d4. A strainer 1C3 having an oil suction opening 1C2 facing the oil pan bottom 1C1 is disposed in the oil pan 1C, and the upper portion of the strainer 1C3 is connected to the oil suction port Op1 of the oil pump Op.

  The lubricating oil sucked into the oil pump Op through the oil passage A in the strainer 1C3 and discharged from the oil pump Op is supplied to the oil filter Of through the oil passage B, and the lubricating oil purified by the oil filter Of is oil. The oil is supplied to the oil cooler Oc via the path C and is cooled by cooling water described later. The cooled lubricating oil is supplied to the main gallery E through the oil passage D.

  The lubricating oil supplied to the main gallery E is supplied to each bearing portion of the crankcase 1 through the oil passage F, and further to the large end portions of the crankpin 1b and the connecting rod 1c through an oil passage (not shown) in the crankshaft 1a. Is supplied to a rotating sliding portion such as the like, and is used for lubrication and cooling of the rotating portion of the crankshaft 1a. The arrows in the figure indicate the flow of the lubricating oil. A relief valve Rv is provided in the oil passage G branched from the oil passage B, and the hydraulic pressure is released when excessive hydraulic pressure is generated.

  The water pump Wp is illustrated in FIGS. 3-1, 3-4, and the like. Although not clearly shown in these drawings, the water pump Wp is coaxial with the above-described oil pump Op, and the lower part of the internal combustion engine E, that is, both the pumps Wp and Op are mounted coaxially so that the lower crankcase. The water pump Wp is positioned so as to be opposed to each other at a position in the vicinity of both sides below 1B, and the water pump Wp is driven together with the oil pump Op via the chain 1d4 from the main shaft 1d of the transmission section M described above. Driven by the driving force. Details of the cooling water supply by the water pump Wp will be described later.

The internal combustion engine E of the present invention generally has the structure described above.
The above-described internal combustion engine E is an in-line (parallel) multi-cylinder engine, but may be a V-type or single-cylinder internal combustion engine as long as it uses an oil cooler.

  Here, the supply structure of the cooling water supplied from the water pump Wp of the present invention will be described. Referring to FIG. 3A, the cooling water supply passage is shown in association with the structure of the internal combustion engine E. In addition, the flow of the cooling water illustrated in FIG. 3A shows a state after the warm-up operation. FIG. 3-2 shows a cooling water supply system diagram, and FIGS. 3-3 and 3-4 show a side view of a vehicle equipped with the internal combustion engine E equipped with the cooling water supply structure. A figure is shown and Example 1 of the supply structure of cooling water is described based on these figures.

  The discharge port of the water pump Wp is connected via a main cooling water passage 50 to a cooling water intake E2 of a water jacket E1 of a cylinder that is a cooling part of the internal combustion engine E. The main cooling water passage 50 is connected to the internal combustion engine E. At the time of mounting on a vehicle, for the connection, the lower crankcase 1B is connected to the intake port E2 by extending upward from the lower side of the lower side of the lower crankcase 1B through the front side of the upper crankcase 1A. . The cooling water drain E3 of the water jacket E1 is connected to the upper tank R1 of the radiator R via the upstream side passage portion 51A of the first cooling water passage 51.

  More specifically, the radiator upstream passage portion 51A of the first cooling water passage 51 protrudes integrally from the passage portion 51A1 having a predetermined length connected to the cooling water drain port E3 and the upper tank R1 of the radiator R. Formed by a short passage portion 51A2 and a flexible rubber upper radiator hose 51A3 connecting the passage portions 51A1 and 51A2 (see FIG. 3A).

  The lower tank R2 of the radiator R is connected to a thermostat Ts via a flexible rubber-made lower radiator hose 51B3 that forms the radiator downstream passage portion 51B of the first cooling water passage 51, and It is connected to the water pump Wp. Eventually, the first cooling water passage 51 extends from the drain E3 of the water jacket E1 serving as the engine cooling section to the upper tank R1 of the radiator R, the water tube inside the radiator R, the lower tank R2 of the radiator R, and the thermostat Ts and water. A cooling water passage leading to the pump Wp is formed. As a structural feature, the case Ts1 of the thermostat Ts is integrally formed with the case Wp1 of the water pump Wp.

  From the middle of the main cooling water passage 50, a passage forming the third cooling water passage 53 is branched, and this branch passage 53 has the branching portion as one end and the other end is a cooling water intake port of the oil cooler Oc. The cooling water intake side passage portion 53A connected to the cooling water drainage side, and the cooling water drainage side passage portion whose one end is connected to the cooling water drainage port of the oil cooler Oc and the other end is connected to the upper tank R1 of the radiator R 53B.

  Further, a passage that forms the second cooling water passage 52 is provided in the middle of the upstream passage portion 51A of the first cooling water passage 51 that connects the cooling water drain E3 of the water jacket E1 and the upper tank R1 of the radiator R. The branch passage 52 is a passage in which the branch portion is one end and the other end is connected to the thermostat Ts. Therefore, the thermostat Ts is connected to the cooling water intake port with the radiator downstream passage portion 51B of the first cooling water passage 51 and the other end of the second cooling water passage 52, that is, the downstream side 52a. Yes.

  The thermostat Ts senses the temperature of the cooling water flowing into the thermostat Ts, controls the opening of the connection portion, and selects one of the two passages 51 and 52 in the collective connection for the circulation of the cooling water. In other words, the collective connection on the downstream side of the cooling water in the thermostat Ts is that the thermostat Ts is in the first cooling water passage 51 when the temperature of the cooling water is lower than a predetermined value (70 ° to 80 °), such as during warm-up operation of the internal combustion engine E. The intake port on the second cooling water passage 52 side is opened, and the intake port on the first cooling water passage 51 side is opened when the coolant temperature is higher than a predetermined value, and the second cooling water passage 52 is opened. It is designed to close the side intake.

  The cooling water discharge side of the thermostat Ts is a substantial extension of the radiator downstream side passage 51B of the first cooling water passage 51, and the thermostat case Ts1 is integrally formed with the case Wp1 of the water pump Wp. The drain side of Ts is directly connected to the cooling water inlet of the water pump Wp. The valve opening / closing control of the thermostat Ts is based on control using paraffinic wax that expands and contracts by sensing the water temperature.

  The state of the specific piping of the cooling water passage in the first embodiment can be partially seen in the side view of the vehicle shown in FIGS. 3-3 and 3-4. 3-4, which is an enlarged view, shows water pump Wp and cooling water to the third cooling water passage 53 that is a branch passage from the discharge port of the water pump Wp to the water jacket E1 of the cylinder and the oil cooler Oc. A main cooling water passage 50 which is a supply passage is shown.

  Further, the upstream side passage portion 51A of the first cooling water passage 51 connecting the water jacket E1 and the upper tank R1 of the radiator R, and the downstream side of the first cooling water passage 51 connecting the lower tank R2 of the radiator R and the thermostat Ts. Side passage 51B, second cooling water passage 52 which is a bypass branched from the middle of upstream passage portion 51A of first cooling water passage 51 and connected to thermostat Ts is shown, and further a case of water pump Wp The structure of the thermostat case Ts1 formed integrally with Wp1 is partially illustrated.

  The above-described cooling water supply structure performs the following cooling water supply operation. This operation is performed based on the cooling water supply system diagram of FIG. 3-2.

  First, the flow of the cooling water during the warm-up operation at a low temperature such as at the start of the internal combustion engine E is shown in FIG. 3-2 (a), and is attached to the lower part of the crankcase 1 of the internal combustion engine E. The cooling water discharged from the discharge port of the water pump Wp that is rotated along with the operation of the engine E flows through the main cooling water passage 50 and is supplied to the water jacket E1 of the cylinder, which is a cooling part of the engine E, and the like. A part flows through a branch passage which is a third coolant passage 53 that branches in the middle of the main coolant passage 50, and is supplied to the cooling portion of the oil cooler Oc. (Outlined arrow in the figure)

  The cooling water that flows through the main cooling water passage 50 and is supplied to the water jacket E1 that is the cooling portion of the internal combustion engine E passes through the water jacket E1 and is warmed, drained from the jacket drain E3, and the first cooling water. Although it flows to the upstream passage portion 51A of the passage 51, the temperature of the cooling water is lower than a predetermined value, and the thermostat Ts is closed.

  That is, the valve of the thermostat Ts closes the cooling water intake port at the connection portion of the first cooling water passage 51 with the radiator downstream passage portion 51B, and connects to the downstream side 52a of the second cooling water passage 52 that is a bypass. Since the cooling water intake port is open, the flow of the cooling water flows into the second cooling water passage 52, which is a bypass, and flows through the thermostat Ts through the cooling water passage 52, and further the water pump Wp. To reflux. (Shown with slanted arrows)

  On the other hand, the cooling water flowing through the main cooling water passage 50 and flowing into the third cooling water passage 53, which is a branch passage, passes through the cooling portion of the oil cooler Oc and is heated and flows into the upper tank R1 of the radiator R. This cooling water cannot flow to the water tube inside the radiator R in the closed state. Cooling water that cannot flow into the water tube inside the radiator R flows through the first cooling water passage upstream passage portion 51 </ b> A so as to flow backward from the upper tank R <b> 1, and then flows into the second cooling water passage 52. (Shown with slanted arrows)

  This flow of cooling water merges with the above-mentioned flow of cooling water that flows into the second cooling water passage 52 through the water jacket E1 that is a cooling portion of the internal combustion engine E, so that the cooling water intake port of the thermostat Ts. This is a flow that flows through the thermostat Ts through the open mouth and returns to the water pump Wp. The cooling water recirculated to the water pump Wp is discharged again by the pump Wp, and is circulated and supplied to the cooling unit of the internal combustion engine E and the oil cooler Oc cooling unit in the above-described cooling cycle.

  This characteristic structure for supplying the cooling water maintains the warmed water temperature because the circulating cooling water during the warm-up operation does not pass through the radiator R, so that the warm-up performance in the warm-up operation of the internal combustion engine E is improved. There is an advantage that the warm-up operation time of the engine E can be shortened. In addition, the pipe length to the oil cooler Oc is secured during the warm-up operation, the flow of the cooling water to the oil cooler Oc side is suppressed, and the warm-up characteristic can be further improved by reducing the cooling effect of the lubricating oil. it can.

  The flow of the cooling water after the warm-up operation of the internal combustion engine E is such that the cooling water discharged from the discharge port of the water pump Wp flows through the main cooling water passage 50 as shown in FIG. Is supplied to the water jacket E1 of the cylinder, which is a cooling part of the internal combustion engine E, and a part thereof flows through the third cooling water passage 53 branched from the middle of the main cooling water passage 50 to cool the cooling part of the oil cooler Oc. To be supplied. (Outlined arrow in the figure)

  The cooling water flowing through the main cooling water passage 50 and supplied to the cooling portion of the internal combustion engine E passes through the water jacket E1 which is the cooling portion of the engine E, and then the upstream passage portion of the first cooling water passage 51. Since the thermostat Ts is in an open state, that is, the thermostat Ts opens the cooling water intake port of the connecting portion that connects the valve to the downstream passage portion 51B of the first cooling water passage 51. Since the cooling water intake port of the connecting portion connected to the second cooling water passage downstream side 52a that is the bypass is closed, the flow of the cooling water flows through the upstream side passage portion 51A of the first cooling water passage 51. To the upper tank R1 of the radiator R. (Black arrow shown)

  In the upper tank R1 of the radiator R, it merges with cooling water from a third cooling water passage 53 used for cooling an oil cooler Oc described later, passes through the water tube inside the radiator R, and is cooled during this time. The radiator lower tank R2 flows through the downstream passage portion 51B of the first cooling water passage 51, flows through the drainage side of the thermostat Ts through the opening of the cooling water intake port of the thermostat Ts, and is returned to the water pump Wp. It is discharged by the pump Wp and circulated and supplied to the cooling part of the internal combustion engine E and the cooling part of the oil cooler Oc in the above-described cooling cycle. (Outlined arrow in the figure)

On the other hand, the cooling water flowing through the main cooling water passage 50 and flowing into the third cooling water passage 53, which is a branch passage of the passage 50, passes through the cooling portion of the oil cooler Oc, and then enters the upper tank R1 of the radiator R. It flows in and merges with the flow of the cooling water heated through the cooling part of the engine E as described above, and flows along the above-mentioned flow together with the cooling water after passing through the cooling part of the engine E.
The supply of the cooling water in the first embodiment is as described above. The flow of the cooling water after the warm-up operation ensures high cooling efficiency because all of the warmed cooling water is circulated through the radiator.

  Incidentally, the thermostat case Ts1 in the above-described first embodiment is integrally formed with the casing portion Wp1 of the water pump Wp. Instead, the thermostat case Ts1 is illustrated in FIGS. 4-1 to 4-4. The cooling water supply structure is provided with a cooling water supply passage associated with the structure of the internal combustion engine E as shown in FIG. The thermostat case Ts1 is formed integrally with the structure of the radiator R, that is, the thermostat case Ts1 is formed integrally with a part of the radiator core R3 forming material. In addition, the flow of the cooling water illustrated in FIG. 4A shows a state after the warm-up operation.

  The structure of the cooling water passage in the second embodiment is a perspective view showing the relationship between the cooling water supply passage and the structure of the internal combustion engine E, FIG. 4-1 is a cooling water supply system diagram, and FIG. Further, it will be described with reference to the side view of the vehicle shown in FIGS. 4-3 and 4-4. Basically, it has the same cooling system and function as those of the first embodiment, and the thermostat case as described above. Since Ts1 is formed integrally with the structure of the radiator R, a part of the cooling water supply passage is changed accordingly.

  That is, as shown in FIG. 4B, which is a cooling water supply system diagram, in the drawing, the thermostat Ts is integrally formed with the radiator R, and the upstream side passage portion 51 </ b> A of the first cooling water passage 51 is formed. In the first embodiment, the second cooling water passage 52 that is a bypass branching from the middle is disposed on the right side of the internal combustion engine E. However, in the second embodiment, the second cooling water passage 52 is located on the left side of the internal combustion engine E and close to the radiator R. And a structure that is branched. This structural change does not change the basic structure of the cooling water supply system in the first embodiment. Therefore, the flow of the cooling water during and after the warm-up operation in the second embodiment is shown in FIG. As shown in FIGS. 4A and 4B, the embodiment is not substantially different from the first embodiment, and the description thereof is omitted.

  And the concrete piping structure of the cooling water channel | path in this Example 2 can be seen partially in FIGS. 4-3 and 4-4 which illustrate a side view of a vehicle. In these drawings, the radiator R, the upstream side passage portion 51A of the first cooling water passage 51 connected to the upper tank R1 of the radiator R, and a branch from the middle of the passage portion 51A are integrated with the radiator R. One end of the second cooling water passage 52 connected to the thermostat Ts including the formed case Ts1 and the water tube inside the radiator R are connected to the thermostat Ts in order to communicate with the water tube via the thermostat Ts. A downstream side passage portion 51B of the first cooling water passage 51 whose other end is connected to the water pump Wp is illustrated.

  Further, a water pump Wp and an oil cooler Oc are illustrated, and cooling water is supplied from a discharge port of the water pump Wp to a water jacket E1 of a cylinder that is a cooling unit of the internal combustion engine E, and the cooling water is supplied to the oil cooler Oc. The main cooling water passage 50 and the like supplied to the third cooling water passage 53 which is a branch passage to the cooling unit are partially illustrated.

  Furthermore, as another embodiment 3, the cooling water supply structure shown in FIGS. 5-1 to 5-4 can be adopted, and this cooling water supply structure has a thermostat case Ts1 disposed between the radiator R and the water pump Wp. Although not clearly shown, the case Ts1 is fixed to a part of the vehicle body frame 10 or a part of the engine E, and the thermostat Ts is connected to the radiator R and the water pump Wp. Is characterized by a completely separate structure, and this structure is a perspective view of a cooling water supply passage associated with the structure of the internal combustion engine E, and FIG. 5 is a cooling water supply system diagram. -2, and a side view of the vehicle shown in FIGS. 5-3 and 5-4. In addition, the flow of the cooling water illustrated in FIG. 5A shows the state after the warm-up operation.

  The third embodiment also basically has the same cooling system and function as the first embodiment, and as described above, the thermostat case Ts1 is disposed on the cooling water passage 51B between the radiator R and the water pump Wp, and the vehicle body frame. 10 or a part of the engine E, and the thermostat Ts is a separate structure from the radiator R and the water pump Wp. has been edited.

  As shown in FIG. 5B, the thermostat case Ts <b> 1 is disposed on the downstream side passage portion 51 </ b> B of the first cooling water passage 51, and the cooling water passage in the third embodiment The second cooling water passage 52, which is a bypass branched from the middle of the upstream passage portion 51A, is disposed on the right side of the internal combustion engine E in the first embodiment, whereas the second cooling water is provided in the third embodiment. The water passage 52 is disposed on the left side of the internal combustion engine E.

  And since the cooling water channel | path 52 is connected to the thermostat Ts on the 1st downstream channel | path part 51B, the connection position is made in the position away from the radiator R and the water pump Wp. Since this structural change does not change the basic structure of the cooling water supply system in the first embodiment, the flow of the cooling water during and after the warm-up operation in the third embodiment is shown in FIG. As shown in a) and FIG. 5-2 (b), this embodiment is not substantially different from the first embodiment, and the description thereof is omitted.

  FIGS. 5-3 and 5-4 illustrating a side view of the vehicle, the radiator R, the upstream side passage portion 51A of the first cooling water passage 51 connected to the upper tank R1 of the radiator R, and A downstream passage portion 51B of a first cooling water passage 51 connected to the lower tank R2 of the radiator R and connecting the radiator R and the water pump Wp, and a thermostat case Ts1 disposed on the passage portion 51B are illustrated. .

  Further, the second cooling water passage 52 branched from the middle of the upstream passage portion 51A of the first cooling water passage 51 connected to the thermostat case Ts1, the water pump Wp, the oil cooler Oc, and the water pump Wp. A main cooling water passage 50 and the like for supplying cooling water from the discharge port to the third water cooling passage 53 that is a branch passage to the water jacket E1 of the cylinder that is the cooling portion of the internal combustion engine E and the cooling portion of the oil cooler Oc. Each is partially illustrated.

  Here, the advantages of the operational effect in cooling the engine in the above-described embodiment of the present invention will be briefly described in comparison with the reference example. In addition, although each Example of this invention differs in the attachment structure of thermostat Ts, since there is no essential difference in a cooling water supply system, Example 3 (FIG. 5-2) is made into a representative example here. A comparison is made.

  In the reference example which is the cooling water supply system illustrated in FIG. 6A, during the warm-up operation at the start of the internal combustion engine E, as illustrated in FIG. The cooling water supplied to the cooling part of the engine E (the white arrow in the figure) passes through the cooling part of the engine E and flows through the upstream side passage part 51A of the first cooling water passage 51, but the thermostat Ts is closed. Without flowing to the R side, it flows to the second cooling water passage 52, which is a branch cooling water passage (bypass), and is directly returned to the water pump Wp (indicated by the hatched arrow in the figure).

  The flow from the main cooling water passage 50 to the oil cooler Oc, which is the third cooling water passage 53 branched from the main cooling water passage 50 (the white arrow in the figure), passes through the cooling part of the oil cooler Oc, and then the radiator of the first cooling water passage 51 It flows directly into the downstream passage 51B and returns to the water pump Wp (indicated by the hatched arrow in the figure).

  After the warm-up operation, as shown in FIG. 6B, the cooling water (the white arrow in the figure) supplied from the main cooling water passage 50 to the cooling unit of the engine E is the cooling unit of the engine E. After passing through the first cooling water passage 51, it flows through the upstream side passage portion 51A, and since the thermostat Ts is opened, the passage is passed through the passage portion 51A and is supplied to the upper tank R1 of the radiator R (black arrow in the figure). R passes through the water tube inside R, flows from the lower tank R2 through the radiator downstream passage portion 51B of the first cooling water passage 51, and returns to the water pump Wp (the white arrow in the figure).

  Further, the cooling water (the white arrow in the figure) that flows from the main cooling water passage 50 to the oil cooler Oc passes through the cooling portion of the oil cooler Oc, and then the radiator downstream side passage portion 51B of the first cooling water passage 51. To the water pump Wp, where it merges with the flow of the cooling water that has passed through the radiator R.

  In this case, the cooling water to the engine E when the internal combustion engine E is warmed up and the cooling water to the oil cooler Oc do not pass through the radiator R, so the temperature of the cooling water rises relatively quickly. Therefore, the warm-up operation time is shortened and the warm-up characteristics are excellent. However, after the warm-up operation of the engine E, the cooling water heated by the oil cooler Oc returns to the water pump Wp without passing through the radiator R and circulates in the engine E, so the cooling effect by the cooling water is deteriorated by that amount. Will do.

  Further, in the reference example of the cooling water supply system shown in FIG. 6B, during the warm-up operation of the internal combustion engine E, as shown in FIG. The cooling water supplied to the cooling section E (the white arrow in the figure) passes through the cooling section of the engine E and then flows through the upstream passage section 51A of the first cooling water passage 51, but the thermostat Ts is closed. Without flowing to the radiator R side, it flows to the second cooling water passage 52, which is a branch cooling water passage, and is directly returned to the water pump Wp (indicated by the hatched arrow in the figure).

  In addition, the flow to the oil cooler Oc, which is the third cooling water passage 53 branched from the main cooling water passage 50 (the white arrow in the figure), passes to the upper tank R1 of the radiator R after passing through the cooling portion of the oil cooler Oc. Flows (indicated by the hatched arrow in the drawing), passes through the water tube inside the radiator R, flows into the radiator downstream passage 51B of the first cooling water passage 51, and returns to the water pump Wp (open arrow in the drawing). .

  After the warm-up operation, as shown in FIG. 6B, the cooling water (the white arrow in the figure) supplied from the main cooling water passage 50 to the cooling unit of the engine E is the cooling unit of the engine E. After passing, the refrigerant flows into the upstream passage portion 51A of the first cooling water passage 51 and flows through the passage portion 51A to the upper tank R1 of the radiator R because the thermostat Ts is open (the black arrow in the figure).

  Further, the cooling water that flows through the third cooling water passage 53 branched from the main cooling water passage 50 (indicated by the white arrow in the drawing) and passes through the cooling portion of the oil cooler Oc flows into the upper tank R1 of the radiator R (shown in the drawing). Here, the two flows merge, pass through the water tube inside the radiator R, flow from the lower tank R2 through the radiator downstream passage portion R2 of the first cooling water passage 51, and the water pump Wp. (Returned arrow in the figure).

  In this case, the cooling water that has flowed into the oil cooler Oc is warmed by passing through the cooling part of the oil cooler Oc even during the warm-up period, but passes through the water tube inside the radiator R from the upper tank R1 of the radiator R. Thus, since the coolant is returned from the radiator lower tank R2 to the water pump Wp, the temperature rise of the cooling water is suppressed, and the warm-up operation time is increased correspondingly, and the warm-up characteristics are poor. Therefore, measures such as providing a thermo valve in the cooling passage of the oil cooler Oc are required to improve warm-up characteristics.

  However, after the warm-up operation, the cooling water warmed by the oil cooler Oc also passes through the radiator R, so that the cooling performance is excellent. Therefore, the oil cooler Oc and the radiator R can be reduced in size.

  FIG. 6-3 (cooling water supply system of Example 3 (see FIG. 5-2)) is shown in FIG. 6-3 in contrast to the reference example of the cooling water supply system shown in FIGS. According to the cooling water supply system in the representative example of the embodiment of the present invention, during the warming-up (closed thermostat), as shown in FIG. The cooling water (indicated by the slanted lines in the figure) circulates and is excellent in warm-up characteristics. Even if cooling water flows through the oil cooler Oc, it does not flow into the water tube inside the radiator R, so the temperature of the heated cooling water (indicated by the hatched line in the figure) is maintained as it is, and the warm-up operation is performed by circulating the cooling water at a low water temperature. Since there is no adverse effect of time, the warm-up characteristics are good and the warm-up operation time can be shortened.

  Further, after the warm-up operation, as shown in FIG. 6-3 (b), the warmed cooling water after passing through the cooling part of the engine E (shown in black) and the cooling part of the oil cooler Oc. The later warmed cooling water (shown in the black arrow) joins upstream of the radiator R, passes through the water tube inside the radiator R, is cooled, and is returned to the water pump Wp (shown in the white arrow). Cooling performance is good, and stabilization of the water temperature near the thermostat Ts working water temperature is achieved with the adoption of bottom bypass entrance control by the thermostat Ts.

  After all, in the embodiment of the present invention, the outlet of the oil cooler Oc is the first cooling water passage 51 (more specifically 51A) which is the main cooling water passage downstream of the connection point of the second cooling water passage 52 which is a bypass passage. Therefore, when the thermostat Ts is opened, the oil cooler Oc side cooling water directly merges with the main cooling water passage downstream of the bypass passage connection point, so that the main cooling water passage of the oil cooler Oc side cooling water passage connection conversion is switched. Therefore, it is not necessary to secure a sufficient amount of cooling in excess of the flow rate required by the cooling unit. Further, when the thermostat Ts is closed, as described above, it is only necessary to secure a capacity in the first cooling water passage 51, which is the main cooling water passage, for the required flow rate. Can be improved.

Since this invention is provided with the structure mentioned above, there exist the following effects.
Since all the cooling water during the warm-up operation is recirculated to the water pump Wp without passing through the radiator R, the warm-up performance is improved. In addition, after the warm-up operation, all the cooling water is cooled via the radiator R, and returned to the water pump Wp to be circulated, so that high cooling performance is ensured.

  A third cooling water passage 53 dedicated to the oil cooler Oc branched from the main cooling water passage 50 for supplying the cooling water to the cooling portion of the internal combustion engine E and connected to the upstream side of the radiator R is provided. The cooling water flowing through 53 passes through the cooling part of the oil cooler Oc to cool the lubricating oil, and during the warming-up operation, the cooling water is recirculated and circulated to the water pump Wp without passing through the radiator R. Characteristics are improved. In addition, securing the piping length of the cooling water passage to the oil cooler Oc suppresses the flow of the cooling water to the oil cooler Oc during the warm-up operation, thereby lowering the cooling efficiency of the lubricating oil, resulting in a warm-up characteristic. Is improved.

  In the case where the thermostat case Ts1 that accommodates the thermostat Ts is formed integrally with the water pump case Wp1, the number of parts can be reduced and the space can be saved by integrating these cases. In addition, since piping downstream of the collecting portion is not necessary, the piping length can be shortened, leading to weight reduction of the cooling device structure.

  In the case where the thermostat case Ts1 for accommodating the thermostat Ts is formed integrally with the structure of the radiator R, the number of parts can be reduced and the space can be saved by integrating the case. Since the length of the cooling water passage 52 can be reduced, the weight of the cooling device structure can be reduced.

  In the case where the thermostat case Ts1 for accommodating the thermostat Ts is formed on the downstream side passage portion 51B of the first cooling water passage 51 connecting the radiator R and the water pump Wp and separately from the radiator R and the water pump Wp. Since the thermostat Ts and its case Ts1 can be shared by a plurality of models, the cost can be reduced. Further, since the thermostat Ts can be fixed at an arbitrary position, that is, at a position corresponding to the shape of the internal combustion engine E or the vehicle, versatility can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a vehicle on which a water-cooled internal combustion engine equipped with a cooling device of the present invention is mounted, and a part thereof is shown as a cut surface. It is a sectional side view which shows the principal part of the internal combustion engine of this invention. It is a figure which shows Example 1 of this invention, and is the perspective view by which the cooling water supply path was shown linked | related with the structure of the engine. It is a figure which shows the cooling water supply system | strain in Example 1 of this invention. It is a figure which shows the side view of the vehicle provided with the cooling water supply structure in Example 1 of this invention. It is a figure which expands and shows the principal part in FIGS. 3-3 of this invention. It is a figure which shows Example 2 of this invention, and is the perspective view by which the cooling water supply path was shown linked | related with the structure of the engine. It is a figure which shows the cooling water supply system in Example 2 of this invention. It is a figure which shows the side view of the vehicle provided with the cooling water supply structure in Example 2 of this invention. It is a figure which expands and shows the principal part in FIGS. 4-3 of this invention. It is a figure which shows Example 3 of this invention, and is the perspective view by which the cooling water supply path was shown linked | related with the structure of the engine. It is a figure which shows the cooling water supply system | strain in Example 3 of this invention. It is a figure which shows the side view of the vehicle provided with the cooling water supply structure in Example 3 of this invention. It is a figure which expands and shows the principal part in FIGS. 5-3 of this invention. It is a figure which shows the reference example of a cooling water supply system. It is a figure which shows another reference example of a cooling water supply system. It is a figure which shows the cooling water supply system of the representative example of the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Crankcase, 1A ... Upper crankcase, 1B ... Lower crankcase, 1a ... Crankshaft, 1d ... Main shaft, 1e ... Counter shaft, 11 ... Main frame , 12 ... Head pipe, 15 ... Swing arm, 50 ... Main cooling water passage, 51 ... First cooling water passage, 51A ... Upstream passage portion, 51B ... Downstream passage , 52 ... second cooling water passage part, 53 ... third cooling water passage part, E ... internal combustion engine, E1 ... water jacket, E2 ... cooling water intake port, E3 ... -Cooling water drain, Op ... Oil pump, Oc ... Oil cooler, R ... Radiator, R1 ... Upper tank, R2 ... Lower tank, Ts ... Thermostat, Ts1 ... Thermostat Case Wp ··· water pump, Wp1 ··· pump case.

Claims (4)

A water pump that discharges cooling water, a cooling portion of the internal combustion engine that cools the internal combustion engine with the cooling water, a lubricating oil cooling portion that cools the lubricating oil with the cooling water, a radiator that cools the cooling water, and these A cooling device for an internal combustion engine comprising a plurality of cooling water flow paths communicating with each other for cooling water flow, and a thermostat for selectively switching the flow path of the cooling water at a predetermined temperature,
The cooling water flow path is a main cooling path in which cooling water is discharged from the water pump and passes through a cooling unit of an internal combustion engine, a radiator, and a thermostat in this order, and is returned to the water pump.
A bypass path connected downstream of the cooling portion of the internal combustion engine and to the thermostat so as to bypass the radiator;
The upstream side of the path through the lubricating oil cooling section is connected between the water pump / internal combustion engine cooling section of the main cooling path, and the downstream side consists of a lubricating oil cooling path connected to the upper tank of the radiator ,
The thermostat is arranged to selectively switch these paths at the predetermined temperature at a portion where the thermostat upstream path of the bypass path is connected to a radiator downstream path of the main cooling path. Engine cooling system.   2. The cooling apparatus for an internal combustion engine according to claim 1, wherein a thermostat case for housing the thermostat is formed integrally with the case of the water pump.   2. The cooling apparatus for an internal combustion engine according to claim 1, wherein a thermostat case for accommodating the thermostat is formed integrally with the radiator structure. 2. The cooling apparatus for an internal combustion engine according to claim 1, wherein a thermostat case for housing the thermostat is disposed on a cooling water passage connecting the radiator and the water pump.

Images