JPH0643449Y2 - Lubricating oil cooling system for internal combustion engines in motorcycles, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a lubricating oil cooling device for an internal combustion engine, and
The present invention relates to a lubricating oil cooling device mounted on a motorcycle or the like and suitably used for an internal combustion engine in which a transmission is integrally provided.

[Prior Art] Generally, in an internal combustion engine mounted on a motorcycle or the like, lubricating oil is supplied to sliding parts and rotating parts for the purpose of reducing friction and removing heat. .

The lubricating oil changes its viscosity by being heated while being circulated inside the internal combustion engine,
Since the lubricating characteristics also change due to this change in viscosity, it is desirable to keep the lubricating oil temperature as constant as possible.

Therefore, conventionally, for example, as shown in JP-A-63-195309, a lubricating oil cooling device is provided in an internal combustion engine, and when the temperature of the lubricating oil rises, the lubricating oil is cooled in a heat exchanger of the lubricating oil cooling device. By cooling, the lubricating oil temperature is maintained at a predetermined temperature or lower, and a lubricating oil bypass passage is provided in the lubricating oil cooling device so that the lubricating oil bypasses the heat exchanger during warm-up operation of the internal combustion engine. A technique for preventing supercooling of the lubricating oil by circulating the oil has been already proposed.

[Problems to be Solved by the Invention] By the way, in particular, in an internal combustion engine mounted on a motorcycle or the like, a transmission is integrally attached to a rear portion of a crankcase, and vibration of the internal combustion engine is generated. In order to cancel the above, a balancer that is driven to rotate by a crankshaft is provided.Furthermore, the balancer is arranged in the front part of the crankcase for the purpose of downsizing the internal combustion engine, and In order to improve the cooling efficiency, it is desired to arrange the cooling device in front of the crankcase.

If the above-mentioned devices are not installed in the internal combustion engine so as to satisfy such conditions, the following problems to be improved occur.

That is, according to the above conditions, the lubricating oil cooling device and the balancer are centrally arranged in the front part of the crankcase, so that the lubricating oil passage and the lubricating oil bypass passage that configure the lubricating oil cooling device and the balancer are They are liable to interfere with each other, and the installation position is limited by the shape of the crankcase or the like to avoid the interference, so that the degree of freedom in design is narrowed.

On the other hand, even if the lubricating oil passage and the lubricating oil bypass passage are provided so as to avoid these interferences, it is assumed that these passages are complicated and lengthened due to the detour of the balancer.

Therefore, conventionally, it has been desired to deal with such a problem, and the present invention is to solve such a problem that remains in the related art.

[Means for Solving the Problems] The present invention provides a lubricating oil cooling device for an internal combustion engine in a motorcycle or the like, which can effectively solve the above-mentioned problems. This lubricating oil cooling device is particularly useful for motorcycles. A lubricating oil cooling device installed in an internal combustion engine, which is mounted on a crankcase, etc., is equipped with a transmission behind the crankcase, and is equipped with a balancer for vibration cancellation. Located in the section,
A heat exchanger for cooling the lubricating oil is arranged in front of the crankcase, and a lubricating oil bypass passage branched from a lubricating oil passage for feeding the lubricating oil to the heat exchanger is formed in the balancer. Is characterized by.

[Operation] According to the present invention, with the above-described configuration, the inside of the balancer is also used as the lubricating oil bypass passage, and it is not necessary to provide a dedicated lubricating oil bypass passage, and the lubricating oil passage is provided with a balancer. And the heat exchanger of the lubricating oil cooling device are brought close to each other to make the internal combustion engine compact, and when forming the lubricating oil passage and the lubricating oil bypass passage. Further, the shape of the crankcase is less restricted and the handling of the lubricating oil passage and the lubricating oil bypass passage is simplified.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, reference numeral 1 indicates an internal combustion engine to which the present embodiment is applied, and a crankcase 3 having a crankshaft 2 mounted thereon and a crankcase 3 integrally mounted substantially above the crankcase 3. A cylinder block 4, a cylinder head 5 attached above the cylinder block 4, a head cover 6 provided over the cylinder head 5, and an oil pan 7 attached below the crankcase 3. , The cylinder head 5
A carburetor G that is connected to the rear of the cylinder head 5, and an exhaust pipe H that is routed downward from the front portion of the cylinder head 5 through the front portion of the crankcase 3.

The crankshaft 2 includes the cylinder block 4
Plural pistons 8 which are slidably fitted inside are connected through a connecting rod 9, and one end portion (the end portion on the right side in FIG. 2) of the piston 8 is projected to the outside of the crankcase 3, A drive sprocket 10 for transmitting power to a cam shaft (not shown) mounted on the cylinder head 5 is attached to the projecting end portion.

A cam chain 11 is wound between the drive sprocket 10 and the cam shaft, and the cam chain 11 transmits power from the crank shaft 2 to the cam shaft. There is.

A drive gear 13 for transmitting power to a mission 12 disposed in the crankcase 3 is integrally provided near one end of the crankshaft 2 and mounted on a main shaft 14 of the mission 12. Clutch
It is meshed with 15 drive gears 16.

Further, the other end of the crankshaft 2 is projected to the outside of the crankcase 3 as shown in FIGS. 1 to 4, and the water pump 17 is attached to the protruding end.
A drive sprocket 18 for transmitting power to is attached.

The drive sprocket 18 can also be directly formed on the crankshaft 2.

As shown in FIG. 1 and FIG. 3 to FIG. 6, the front portion of the crankcase 3 is provided with a recess A that opens forward, and by forming this recess A, A side wall 3a is formed along the side surface of the crankcase 3, the water pump 17 is disposed in the recess A, and the water pump 17 is fixed to the side wall 3a by a bolt 26.

As shown in FIGS. 3 and 4, the water pump 17 includes a body 20 on which a driven shaft 19 is rotatably mounted, an impeller 21 attached to one end of the driven shaft 19, and a driven shaft 19. A driven sprocket 22 attached to the other end of the body, an impeller 21 attached to the body 20 and a cooling water suction port 23a (see FIG. 3) and a discharge port 23b (see FIG. 4). And a formed cover 23.

A boss portion 20a into which the driven shaft 19 is inserted is formed in the body 20, and a bearing 24 that rotatably supports the driven shaft 19, a body 20 and the driven shaft 19 are formed in the boss portion 20a. And a seal 25 for maintaining a liquid-tight state between them.

Then, the water pump 17 having such a configuration is
As shown in FIG. 3, the boss portion 20a of the body 20 is fitted into the through hole 36b formed in the side wall 3a from the inside of the recess A while being disposed in the recess A. It is positioned with respect to the crankcase 3 and, as shown in FIG. 4, is fixed to the side wall 3a by a bolt 26 penetrating the side wall 3a.

The water pump 17 fixed in this way is
As shown in FIGS. 3, 3 and 4, the other end of the driven shaft 19 is projected to the outside of the side wall 3a of the crankcase 3 together with the driven sprocket 22. A chain 27 wound between the crankshaft 2 and a drive sprocket 18 attached to the other end of the crankshaft 2 is connected to the crankshaft 2 so that the crankshaft 2 can be driven to rotate.

Meanwhile, the driven sprocket 2 of the water pump 17 is
2, the drive sprocket 18 attached to the crankshaft 2, and the chain 27 wound between them are the covers attached to the side portions of the crankcase 3, as shown in FIGS. 3 and 4. Covered by 28.

As shown in FIG. 5, the suction port 23a of the water pump 17 has a cooling water suction passage B formed in a cover 29 mounted on the front surface of the crankcase 3, the cover 29 and the crankcase 3 as shown in FIG. Is connected to a radiator (not shown) through a cooling water flow path C formed between the front surface of the cover and a front surface of the cover 29, and through a bypass path D formed in the cover 29.
It is connected to a water jacket formed in the cylinder head.

The bypass passage D is branched from a confluence portion of the cooling water suction passage B and the cooling water passage C, and the cooling water suction passage B is attached to the branch point. The cooling water passage C and the bypass passage D are selectively communicated with each other.

Further, the discharge port 23b of the water pump 17 is connected to the lubricating oil cooling device 32 according to the present embodiment provided in the front part of the crankcase 3 via the cooling water passage E formed in the cover 29. In addition, the crankcase 3
Is communicated with the water jacket 30 through the communication ports 33, 34 formed on the front surface of the.

The water pump 17 supplies cooling water to the cylinder block 4
In addition to being circulated to the cylinder head 5 and the cylinder head 5, the cooling water is also circulated to the lubricating oil cooling device 32.

The lubricating oil cooling device 32 according to the present embodiment includes a heat exchanger 35 attached to the front end surface of the crankcase 3, and the suction portion 35a of the heat exchanger 35 is shown in FIGS.
And, as shown in FIG. 7, the lubricating oil passage 36 formed in the side wall of the crankcase 3 is connected, and the lubricating oil passage 36 is connected to the lubricating oil pump 37 shown in FIG. As a result, the lubricating oil discharged from the lubricating oil pump 37 is changed to a chain line arrow (a) in FIGS. 3 to 5 and 7.
As shown in FIG. 7, the cooling water supplied from the cooling water passage E is brought into contact with the surface as shown by the solid arrow (B) in FIG. The heat exchange is performed between the lubricating oil and the cooling water.

In addition, the discharge portion 35b of the heat exchanger 35 has a lubricating oil passage formed in the crankcase 3 so as to be separated from the lubricating oil passage 36.
The lubricating oil passage 38 is communicated with the lubricating oil passage 38, and the lubricating oil passage 38 is provided on the front surface of the crankcase 3 to the lubricating oil filter 39 provided at the side of the lubricating oil cooling device 32.
(See FIG. 6 to FIG. 6), the lubricating oil after cooling is supplied to the lubricating oil filter 39.

On the other hand, the lubricating oil supplied to the lubricating oil filter 39 is filtered by the lubricating oil filter 39 and then discharged from the outlet.
It is adapted to be fed into each part of the internal combustion engine 1 from 41 via a lubricating oil supply path 42 and a main gallery 43 formed in the crankcase 3.

Further, the lubricating oil passage 36 is a suction part of the heat exchanger 35.
It is connected to the lubricating oil bypass passage 44 in the vicinity of 35a.

As shown in FIGS. 3 and 4, the lubricating oil bypass passage 44 passes through the inside of the balancer 45 arranged in the front portion of the crankcase 3 so as to be parallel to the crankshaft 2. The suction port 46 of the lubricating oil filter 39 is communicated with.

Then, by providing a thermostat (not shown) in the lubricating oil passage 36 or by providing an orifice in the lubricating oil bypass passage 44, the lubricating oil pump
If the temperature of the lubricating oil discharged from 37 is low,
Most of the oil is supplied from the lubricating oil bypass passage 44 to the lubricating oil filter 39.
After the lubricating oil temperature reaches a predetermined temperature, most of the lubricating oil is sent to the heat exchanger 35.

The balancer 45 is fitted on the outside of the pipe 47 supported by the crankcase 3, and is rotatably supported via a bearing 48 interposed therebetween, and
A driven gear 49 that is meshed with the drive gear 13 of the crankshaft 2 is integrally provided at one end of the balancer 45, and can be rotated by the crankshaft 2 in a direction opposite to the rotation direction thereof. ing.

Further, at the other end of the balancer 45, there is provided a balance weight 50 for canceling the vibration of the internal combustion engine 1 by the above-mentioned rotation.

The heat exchanger 35 and the cover 29 provided on the front surface of the crankcase 3 that constitutes the lubricating oil cooling device 32 are
It is located in the space formed between the crankcase 3 and the exhaust pipe H routed in front of it.

Therefore, according to the lubricating oil cooling device 32 of the internal combustion engine 1 of the present embodiment, the heat exchanger 35, which is a component thereof, is arranged in the front surface of the crankcase 3, and the lubricating oil bypass passage 44 is provided in the crank. Since the balancer 45 is formed in the front portion of the case 3, they are brought close to each other with the front wall of the crankcase 3 interposed therebetween, and as a result, the lubricating oil bypass passage 44 and the heat exchanger 35 are separated from each other. Lubricating oil passages such as the lubricating oil passage 36 formed between the suction portion 35a and the like are shortened, and the balancer 45 is also used as the lubricating oil bypass passage 44. Planned.

By integrating the balancer 45 and the lubricating oil bypass passage 44, the area occupied by them is narrowed, and the degree of freedom in the layout is increased.

On the other hand, since the lubricating oil cooling device 32 is centrally arranged in the front portion of the crankcase 3, the cooling effect can be improved by the action of traveling wind.

Further, by mounting the constituent elements of the lubricating oil cooling device 32 on the front portion of the crankcase 3, these function as a reinforcing material, and as a result, the rigidity of the crankcase 3 is increased.

The lubricating oil cooling device 32 includes a lubricating oil bypass passage.
In the case where the orifice is provided in 44, when the lubricating oil temperature is low, the viscosity of the viscosity causes the flow path resistance between the heat exchanger 35 and the lubricating oil filter 39 to lubricate from the orifice and the lubricating oil bypass passage 44. Since the resistance becomes larger than the flow path resistance up to the oil filter 39, most of the lubricating oil is sent to the lubricating oil filter 39 from the lubricating oil bypass passage 44.

Therefore, the supercooling of the lubricating oil is prevented, and the lubricating oil is heated to a temperature at which an appropriate viscosity is obtained.

When the thermostat type flow path switching valve is used, the heat exchanger 35 and the lubricating oil bypass passage 44 are switched depending on the lubricating oil temperature so that all of the lubricating oil is in the lubricating oil bypass passage.
It is sent to the 44 side.

Further, when the orifice is used, if the decrease in viscosity gradually progresses due to the increase in lubricating oil temperature, the heat exchanger
The flow path resistance at 35 gradually decreased and this heat exchanger
When the amount of lubricating oil passing through the heat exchanger 35 increases and the heat exchanger 35 cools the lubricant oil and reaches a predetermined temperature or higher, most of the lubricant oil is sent to the heat exchanger 35 and its temperature is exceeded. The rise is controlled.

On the other hand, the water pump 17 is driven by the crankshaft 2 when the internal combustion engine 1 is started, and when the cooling water temperature is low, the communication of the cooling water passage C and the water pump 17 is cut off by the action of the thermostat 31. Therefore, as shown by the arrow (c) in FIG. 5, in the order of water jacket 30, bypass passage D, cooling water suction passage B, water pump 17, cooling water passage E, oil cooler 32, and water jacket 30. Circulating cooling water prevents supercooling of the internal combustion engine 1.

Also, after the cooling water temperature reaches the predetermined temperature,
By the action of the thermostat 31, the communication between the bypass passage D and the water pump 17 is cut off, so that the water jacket 30 → radiator → cooling water passage C → cooling water suction passage B → water pump 17 → cooling water passage E → oil. Cooler 32
→ Cooling water is circulated in the order of the water jacket 30 to cool the cylinder block 4 and the cylinder head 5 and the lubricating oil.

It should be noted that the shapes, sizes, etc. of the respective constituent members shown in the above embodiments are merely examples, and can be variously changed based on the type of internal combustion engine or water pump to be applied, design requirements, or the like.

[Advantages of the Invention] As described above, the lubricating oil cooling device for an internal combustion engine in a motorcycle or the like according to the present invention is mounted on a motorcycle or the like, and a transmission is provided at a rear position of a crankcase, and A lubricating oil cooling device provided in an internal combustion engine equipped with a balancer for canceling vibrations, wherein the balancer is arranged in a front portion of a crankcase,
A heat exchanger for cooling the lubricating oil is arranged in front of the crankcase, and a bypass passage branched from a lubricating oil passage for feeding the lubricating oil to the heat exchanger is formed in the balancer. And has the following excellent effects.

By using the inside of the balancer also as a lubricating oil bypass passage, it is not necessary to provide a dedicated lubricating oil bypass passage, and the lubricating oil passage and the balancer are crossed, which allows heat exchange between the balancer and the lubricating oil cooling device. The internal combustion engine can be made compact by simplifying the handling of both passages by bringing them into close proximity with each other.

Further, when forming the lubricating oil passage and the lubricating oil bypass passage, the lubricating oil bypass passage can be formed separately from the crankcase, so that these can be formed without being limited by the shape of the crankcase. ,
The degree of freedom in design can be greatly expanded.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention. FIG. 1 is a side view of an internal combustion engine to which the embodiment is applied, and FIG. 2 is II of FIG.
-II is a cross-sectional view taken along the line, FIGS. 3 and 4 are cross-sectional views showing the front part of the crankcase, FIGS. 5 and 6 are front views of the crankcase, and FIG. VI in the figure
FIG. 7 is a sectional view taken along line I-VII. 1 ... Internal combustion engine, 3 ... Crankcase, 32 ... Lubricating oil cooling device, 33 ... Communication port, 34 ... Communication port, 35 ... Heat exchanger, 35a ... Suction part, 35b ... Discharge part , 36 …… Lubricating oil passage, 37 …… Lubricating oil pump, 38 …… Lubricating oil passage, 44 …… Lubricating oil bypass passage, 45 …… Balancer, 47 …… Pipe, 48 …… Bearing, 49 …… Driven gear, 50 …… Balance weight.

Claims (1)

[Scope of utility model registration request] 1. A lubricating oil cooling device provided in an internal combustion engine mounted on a motorcycle or the like, provided with a transmission at a rear position of a crankcase, and equipped with a balancer for vibration cancellation. The balancer is arranged in the front part of the crankcase, and a heat exchanger for cooling the lubricating oil is arranged in front of the crankcase, and the heat exchanger is branched from a lubricating oil passage for feeding the lubricating oil. A lubricant oil cooling device for an internal combustion engine in a motorcycle or the like, characterized in that a lubricant oil bypass passage is formed in the balancer.