JP4246130B2 - Oil passage arrangement structure of internal combustion engine - Google Patents

Description

  The present invention relates to an arrangement structure of a lubricating oil passage in an internal combustion engine for a small vehicle.

  As a conventional technique, there is an example of a configuration in which an oil filter is disposed in a front portion of a lower crankcase, and an oil filter and a main gallery are disposed offset from a crankshaft in a side view of the internal combustion engine (for example, Patent Document 1). reference.).

Japanese Patent No. 3180540.

  In the conventional configuration, when the oil is passed from the oil pan to the oil filter, the path is not linear but greatly detoured, so the oil path is long and pressure loss occurs. Further, the passage formation for distributing oil from the main gallery to each journal bearing is long and complicated. An object of the present invention is to provide an oil passage arrangement structure capable of shortening an oil path to a journal portion of a crankshaft and reducing loss.

The present invention solves the above-mentioned problems, and the invention according to claim 1 is directed to an oil pump that supplies oil to each lubrication site, an oil filter that purifies the supplied oil, and a width direction of the internal combustion engine. A crankshaft that is disposed and the oil is supplied to the journal portion, a main gallery that is disposed in parallel with the crankshaft and serves as an oil passage for supplying oil to each journal portion of the crankshaft, and a crankcase that incorporates the crankshaft; In the oil passage arrangement structure of the internal combustion engine provided with an oil pan connected to the lower part of the crankcase , the oil filter, the main gallery, and the crankshaft are arranged in a substantially straight line in the cylinder direction in a side view of the internal combustion engine. The oil filter outlet pipe from the oil filter is connected to the center of the main gallery in the width direction of the internal combustion engine, The oil filter is attached to the lower surface of the oil pan, the oil filter mounting portion to the oil pan is provided in a portion that forms a shallow bottom portion of the oil pan, and the main gallery is disposed below the crankcase. It is arranged closer to the crankshaft than the part to be connected, and the mounting portion of the oil filter to the oil pan is raised in the oil pan, and the height of the mounting portion is such that the oil pan is below the crankcase. An oil passage arrangement structure of an internal combustion engine characterized by being higher than a connected portion .

According to a second aspect of the present invention, in the oil passage arrangement structure for an internal combustion engine according to the first aspect, an oil filter protective wall extending downward from the internal combustion engine is provided around the oil filter mounting portion. And

According to a third aspect of the present invention, in the oil passage arrangement structure of the internal combustion engine according to the first aspect , an oil filter protective wall extending downward from an outer peripheral portion of the oil filter mounting portion is provided, and the oil filter protective wall is The oil pan is connected to the oil pan and exposed downward from the lower surface of the shallow bottom portion to the oil pan.

According to a fourth aspect of the present invention, in the oil passage arrangement structure of the internal combustion engine according to any one of the first to third aspects, the oil filter inlet oil passage for supplying oil from the oil pump to the oil filter is It is provided in the crankcase at a position below the main gallery and above the oil filter.

According to a fifth aspect of the present invention, in the oil passage arrangement structure of the internal combustion engine according to the fourth aspect , in the plan view, the oil filter is disposed substantially in the center in the left-right direction of the oil pan, and the oil filter inlet oil passage Is arranged at a position not overlapping with the oil filter.
According to a sixth aspect of the present invention, in the oil passage arrangement structure of the internal combustion engine according to the fourth or fifth aspect, the oil filter inlet oil passage, the oil filter outlet pipe from the oil filter, and the main gallery are rectangular. It is characterized by being connected.
The invention according to claim 7 is the oil passage arrangement structure of the internal combustion engine according to any one of claims 1 to 6, wherein a baffle plate is arranged so as to cover the oil filter mounting portion.
According to an eighth aspect of the present invention, in the oil passage arrangement structure of the internal combustion engine according to any one of the first to seventh aspects, the height of the oil filter mounting portion is such that oil lubricated each part of the internal combustion engine returns to the oil pan. It is characterized by being higher than the opening height of the oil pan inlet which is a part.

According to the first aspect of the invention, the oil path from the oil filter to the journal portion of the crankshaft can be shortened, and the pressure loss can be reduced. Further, since the oil cleaned by the oil filter can be supplied to the journal part through a short path, the wear of the journal part can be reduced. Also, friction can be reduced. Furthermore, oil can be uniformly supplied to each journal bearing portion while shortening the oil passage. Further, since the oil filter position is also located substantially in the center of the internal combustion engine, the oil path from the oil filter can be arranged in the dead space of the vehicle, and the size can be reduced. In addition, since the oil path can be shortened, it is possible to prevent oil from adhering to the crankcase or the like when replacing the oil filter. Furthermore, the oil filter can be prevented from protruding and the oil passage can be further shortened. Further, since the oil filter can be mounted at a position close to the lower crankcase, the mounting rigidity is improved.

According to the second aspect of the invention, the oil filter can be protected against a collision with a stepping stone or the like.

According to the invention of claim 3 , the oil filter exposed from the oil pan can be reliably protected while reducing the number of parts. The oil filter can be protected against a collision with a stepping stone or the like.

According to the invention of claim 4, the oil passage can be compactly and efficiently disposed by disposing the filter inlet oil passage at a position between the main gallery and the oil filter .

According to the invention of claim 5, the oil filter can be provided at a position close to the main gallery without interfering with the oil filter inlet oil passage.
The invention of claim 6 is effective for imparting rigidity to the oil passage.
According to the seventh aspect of the present invention, the undulating oil can be suppressed by the baffle plate.
According to the invention of claim 8, the scattering of oil returning to the oil pan is suppressed.

  FIG. 1 is a view showing a cooling system oil circuit in a view of a longitudinal section of a four-cylinder DOHC wet sump type internal combustion engine 1 according to an embodiment of the present invention as viewed from the right side. Arrow F points forward. In the internal combustion engine 1, a power generation unit 2 and a transmission unit 3 are integrated. The outer shell of the internal combustion engine 1 includes a lower crankcase 5, an upper crankcase 6, a cylinder block 7, a cylinder head 8, a cylinder head cover 9, and an oil pan 10. The crankshaft 11, the main shaft 12 of the transmission, and the countershaft 13 are rotatably supported by bearings on the mating surfaces of the crankcases 5 and 6 that are divided into two vertically.

  The cylinder block 7 has four cylinders, and a piston 15 is slidably accommodated in each cylinder hole 14 and connected to the crankshaft 11 via a connecting rod 16. A combustion chamber 20 is provided below the cylinder head 8 facing the upper surface of each piston 15.

  A spark plug 21 is inserted into the upper center of each combustion chamber 20 from above the cylinder head 8, and its tip faces the combustion chamber 20. The cylinder head 8 is provided with an intake port 22 and an exhaust port 23 connected to each combustion chamber 20, and the inner ends thereof open to the combustion chamber. At the inner end openings of the intake port 22 and the exhaust port 23, an intake valve 24 and an exhaust valve 25 that open and close the respective openings are provided. A valve mechanism 28 including an intake cam shaft 26 and an exhaust cam shaft 27 is provided near the mating surface of the cylinder head 8 and the cylinder head cover 9.

  An oil pan 10 having a shallow bottom portion 10A and a deep bottom portion 10B is connected to the lower portion of the lower crankcase 5. An oil suction pipe 31 having a strainer 30 is provided in the deep bottom portion 10B of the oil pan 10, and an oil pump 32 is connected to the upper portion thereof. The oil pump 32 includes a cooling system oil pump 32A and a lubrication system oil pump 32B, and is connected to the same oil pump shaft 33.

  The internal combustion engine is provided with a cooling system oil circuit and a lubrication system oil circuit independently. Oil is separately supplied to each oil circuit from the cooling system oil pump 32A and the lubrication system oil pump 32B. FIG. 1 shows a cooling system oil circuit, and FIG. 2 shows a lubrication system oil circuit.

  In the cooling system oil circuit of FIG. 1, a cooling system discharge pipe A1 connected to the cooling system oil pump 32A extends upward. This pipe reaches the cooling system supply side oil gallery 38 provided in the cylinder block 7 via the lower crankcase oil passage A2 and the upper crankcase oil passage A3. An oil temperature sensor 47 is provided in the oil gallery 38. The oil path from the oil gallery 38 branches into a cooling system supply oil passage A4 provided for each cylinder in the rear wall of the cylinder block 7, and each oil passage is provided in the cylinder head 8 independently for each cylinder. To the oil jacket 40. The oil jacket 40 is connected to a cooling system return oil passage A5 provided in the front wall of the cylinder block 7, and reaches a cooling system return side oil gallery 42 via a return oil passage A6 provided in the upper crankcase 6.

  From here, the number of oil passages becomes one, and reaches the thermostat 43 through a connecting oil passage A7 provided in the upper crankcase 6. In this apparatus, when the oil temperature is high, the oil port connected to the oil cooler is opened, and the oil flows to the oil cooler connecting pipe A8. When the oil temperature is low, the oil port connected to the oil cooler is closed, and the oil flows into the upper crankcase oil return passage 45 through the bypass passage A9. The return oil from the return connection pipe A10 connected to the oil cooler flows into the lower crankcase oil return passage 46 connected to the flow path 45 via the oil cooler return pipe mounting portion 67. The oil that has flowed into the oil return passages 45 and 46 in the crankcase flows downward and returns into the oil pan 10. The above is the outline of the cooling system oil circuit.

  In the lubrication system oil circuit of FIG. 2, a lubrication system discharge pipe B 1 connected to the lubrication system oil pump 32 B extends forward while curving in the oil pan 10 and is connected to the oil filter 50. A main gallery 51 is provided above the oil filter 50 and below the crankshaft 11 in the lower crankcase, and an oil filter outlet pipe B2 extending from the center of the oil filter 50 is connected thereto. In order to support the crankshaft 11, journal bearings 52 are provided between the plurality of partition walls of the lower crankcase 5 and the plurality of partition walls of the upper crankcase 6. Oil passages B3 branched from the main gallery 51 and directed to the plurality of journal bearings 52 are formed in the walls of the partition walls of the lower crankcase.

  An oil gallery 53 for an oil jet is provided on the upper part of the upper crankcase 6. The oil gallery 53 communicates with one journal bearing 52 at the center by an oil passage B4 formed in the upper crankcase partition wall. A rear injection nozzle 54 connected to the oil jet oil gallery 53 is provided for each cylinder hole 14 to inject oil into the rear of each cylinder hole. Oil for lubricating the chain tensioner 55 is supplied from the oil jet oil gallery 53 through the oil passage B5. A front injection nozzle 56 that communicates with each journal bearing 52 is provided on the upper crankcase partition wall at the side of each cylinder hole 14, and the oil that has passed through the journal bearing 52 is injected into the front of each cylinder hole 14. .

  An oil passage B6 that communicates with the peripheral portion of one journal bearing 52, which is different from the above at the center, and that extends upward in the cylinder is drilled in one of the upper crankcase partition walls. Lubricating oil is sent to the intake camshaft 26 and the exhaust camshaft 27 through the in-head oil passage B8 and the upper oil passage B9. The oil that has lubricated the camshaft and the like returns to the oil pan 10 through the central cam chain chamber. The above is the outline of the lubricating oil circuit.

  3 is a longitudinal sectional view of the vicinity of the oil pan 10, and FIG. 4 is a top view of the vicinity of the oil pan. Arrow F points forward. In these drawings, an oil suction pipe 31 having a strainer 30 is provided at the deep bottom portion 10B of the oil pan 10 and is connected to an oil pump 32. The oil pump 32 includes a cooling system oil pump 32A and a lubrication system oil pump 32B, and is connected to the same oil pump shaft 33. Since the present invention relates to the arrangement structure of the lubrication system oil passage, the following explanation is limited to matters related to the lubrication system.

  An oil filter 50 is attached to the shallow bottom portion 10 </ b> A of the oil pan 10. The oil filter mounting portion 73 is raised in the oil pan, and the raised portion is located between the oil pan inlet 74 and the strainer 30 connected to the outlet of the cooling system oil return passage 46 in a plan view. The height of the oil filter mounting portion 73 raised in the oil pan 10 is higher than the opening height of the oil pan inlet 74. The oil filter mounting portion 73 to the oil pan is provided at a portion forming a shallow bottom portion of the oil pan, that is, a portion closest to the lower crankcase on the lower surface of the oil pan. The outer peripheral portion of the oil filter mounting portion 73 extends downward to form an oil filter protection wall 73a, and the lower end thereof is exposed downward from the lower surface of the oil pan shallow bottom portion 10A. .

  A baffle plate 75 having a surface above the upper surface of the oil filter attaching portion 73 and the strainer 30 is provided so as to cover the upper portion of the oil pan. The baffle plate 75 is made of a metal plate with punched holes, and is used to suppress the waving and scattering of oil in the oil pan 10 during vehicle operation and to prevent foaming.

  A lubrication system discharge pipe B1 connected to the lubrication system oil pump 32B extends forward while curving in the oil pan 10, and is connected to the oil filter 50 via an oil filter inlet oil passage 34. The oil sent to the lubrication point passes through the oil filter 50 and is purified, and the purified oil is sent to the main gallery 51 via the oil filter outlet pipe B2.

FIG. 5 is a cross-sectional view of the oil filter 50 and the vicinity of the main gallery 51 above it, as viewed from the rear. In the figure, the lower crankcase 5 has a lower portion of the cam chain chamber 57 at the center and two crank chambers 17 on both sides thereof. The lower crankcase 5 includes a side wall 5a at both ends and a partition wall 5b that partitions the chambers. A total of six wall bodies are provided. An oil passage B3 connected to the main gallery 51 is provided in these walls, and oil is supplied to the journal portion of the crankshaft 11 through this oil passage. The journal bearing 52 is provided with an oil groove 52a continuous to the entire circumference of the bearing portion.

  FIG. 6 is a rear cross-sectional view of the upper and lower crankcases 5 and 6 and the cylinder block 7. A crankshaft 11 is rotatably supported on a journal bearing 52 between the upper and lower crankcases 5 and 6. Each journal bearing 52 is provided with an oil groove 52a over the entire circumference as described above. The crankshaft is provided with a crankshaft oil passage B10 that opens into the oil groove, and the other end is opened at the large end of the connecting rod 16. The oil sent from the main gallery 51 to the journal bearing 52 through the oil passage B3 lubricates the journal of the crankshaft 11 and the sliding portion at the large end of the connecting rod 16.

  An oil passage B6 is formed in the partition wall 6b of the upper crankcase 6 adjacent to the right side of the cam chain chamber 57. This is connected to an oil passage B7 drilled in the partition wall 7d of the cylinder block 7 and an oil passage B8 drilled in the cylinder head 8, and the oil that has passed through the oil groove 52a of the journal bearing 52 is connected to these oil passages B7. The oil is supplied to the cylinder head 8 via the oil passage, and is used for lubricating the bearing portions and cam nose portions of the cam shafts 26 and 27.

  A front injection nozzle 56 communicating with the oil groove 52a of each journal bearing 52 is provided on the side of the side wall 6a and the partition wall 6b of the upper crankcase 6 corresponding to each cylinder hole 14, and the oil groove 52a of the journal bearing 52 is provided. The oil that has passed through is injected to the front part of each cylinder hole 14, and the sliding part of the piston 15 is lubricated. An oil passage B4 formed in the partition wall 6b of the upper crankcase 6 adjacent to the left side of the cam chain chamber 57 communicates with an oil gallery 53 for an oil jet described later.

  FIG. 7 is a longitudinal sectional view of a main part of the internal combustion engine 1. Arrow F points forward. In the figure, an oil gallery 53 for an oil jet is provided on the upper part of the upper crankcase 6. The oil gallery 53 communicates with an oil passage B4 formed in the partition wall 6b adjacent to the left side of the cam chain chamber 57 in FIG. A rear injection nozzle 54 is connected to the oil gallery 53, and the oil that has passed through the oil groove 52a of the journal bearing 52 is injected to the rear of each cylinder hole 14 through the oil gallery 53 and the nozzle 54, thereby sliding the piston. The moving part is lubricated. Oil is supplied from the oil jet oil gallery 53 to the chain tensioner 55 through the oil passage B5, and the chain tensioner 55 is lubricated.

  The aforementioned front injection nozzle 56 communicating with each journal bearing 52 is provided on the side of the upper crankcase partition wall, and the oil that has passed through the journal bearing 52 is injected into the front of each cylinder hole 14.

  The oil passage B6 provided in the right partition wall 6b (FIG. 6) of the cam chain chamber communicates with the oil passage B7 of the cylinder block 7 and the oil passage B8 of the cylinder head 8, and further penetrates into the cam shaft upper bearing member. It communicates with the provided upper oil passage B9.

  Oil pumped from one journal bearing part of the crankshaft is sent to the intake camshaft 26 and the exhaust camshaft 27 via the oil passage, and the sliding part between the camshaft bearing part and cam crest and valve lifter. Used for lubrication. The oil that has lubricated the camshaft and the like returns to the oil pan 10 through the cam chain chamber 57 at the center.

Since the oil passage arrangement structure of the present embodiment is configured and operates as described above, the following effects are obtained.
(1) As shown in FIG. 2, in the side view of the internal combustion engine, the oil filter, the main gallery, and the crankshaft are arranged in a substantially straight line in the cylinder direction, that is, in the vertical direction. The oil path to can be shortened, and loss can be reduced.
(2) Since the oil path from the oil filter is formed in the central part of the main gallery in the width direction of the internal combustion engine, the oil can be evenly supplied to each journal bearing part while shortening the oil path. Further, since the oil filter position is also located substantially in the center of the internal combustion engine, the oil path from the oil filter can be arranged in the dead space of the vehicle, and the arrangement is compact.
(3) Since the oil filter is attached to the lower surface of the oil pan, the oil path can be shortened. In addition, it is possible to prevent oil from adhering to the crankcase when the oil filter is replaced.
(4) The oil filter mounting part to the oil pan is provided in the shallow bottom part of the oil pan, that is, the part closest to the lower crankcase in the bottom surface of the oil pan. In addition to being suppressed, the oil passage can be further shortened. Moreover, since it can be attached at a position close to the lower crankcase, the attachment rigidity is improved.
(5) Since an oil filter protection wall extending downward from the internal combustion engine is provided around the oil filter mounting portion, the oil filter can be protected against contact with a stepping stone or the like.

It is the figure which showed the cooling system oil circuit of the internal combustion engine of this embodiment. It is the figure which showed the lubrication system oil circuit of the internal combustion engine of this embodiment. It is a longitudinal cross-sectional view near an oil pan. It is a top view of the vicinity of the oil pan. FIG. 5 is a view of a cross section near the oil filter and main gallery 51 as viewed from the rear. It is the figure which looked at the cross section of an up-and-down crankcase and a cylinder block from back. It is a principal part longitudinal cross-sectional view of an internal combustion engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 ... Lower crankcase, 6 ... Upper crankcase, 7 ... Cylinder block, 8 ... Cylinder head, 10 ... Oil pan, 10A ... Shallow bottom part, 10B ... Deep bottom part, 11 ... Crankshaft, 11a ... Journal part, 17 ... Crank 30 ... Strainer, 31 ... Oil suction pipe, 32 ... Oil pump, 32A ... Oil pump for cooling system, 32B ... Oil pump for lubrication system, 34 ... Oil filter inlet oil passage, 50 ... Oil filter, 51 ... Main gallery , 52 ... Journal bearing, 52a ... Oil groove, 53 ... Oil gallery for oil jet, 73 ... Oil filter mounting part, 73a ... Oil filter protective wall

Claims (8)

An oil pump that supplies oil to each lubrication site;
An oil filter for purifying the supplied oil;
A crankshaft that is arranged in the width direction of the internal combustion engine and in which the oil is supplied to the journal portion;
A main gallery that is arranged in parallel with the crankshaft and serves as an oil passage for supplying oil to each journal portion of the crankshaft ;
A crankcase containing the crankshaft;
An oil pan connected to the bottom of the crankcase;
In an oil passage arrangement structure of an internal combustion engine provided with
In a side view of the internal combustion engine, the oil filter, the main gallery, and the crankshaft are arranged on a substantially straight line in the cylinder direction,
The oil filter outlet pipe from the oil filter is connected to the center of the main gallery in the width direction of the internal combustion engine,
The oil filter is attached to the bottom of the oil pan,
The mounting part of the oil filter to the oil pan is provided at a site forming the shallow bottom of the oil pan,
The main gallery is disposed closer to the crankshaft than a portion where the oil pan is connected to the lower part of the crankcase,
The attachment portion of the oil filter to the oil pan is raised in the oil pan, and the height of the attachment portion is higher than a portion where the oil pan is connected to the lower portion of the crankcase. An oil passage arrangement structure for an internal combustion engine. 2. The oil passage arrangement structure for an internal combustion engine according to claim 1, wherein an oil filter protective wall extending downward of the internal combustion engine is provided around the oil filter mounting portion. An oil filter protective wall extending downward from the outer peripheral portion of the oil filter mounting portion is provided, and the oil filter protective wall is connected to the oil pan and exposed downward from the lower surface of the shallow bottom portion to the oil pan. The oil passage arrangement structure for an internal combustion engine according to claim 1, wherein the oil passage arrangement structure is provided. An oil filter inlet oil passage for supplying oil from the oil pump to the oil filter is provided in the crankcase at a position below the main gallery and above the oil filter. 4. An oil passage arrangement structure for an internal combustion engine according to any one of 3 above. 5. The oil filter according to claim 4, wherein the oil filter is disposed substantially in the center in the left-right direction of the oil pan in a plan view, and the oil filter inlet oil passage is disposed at a position not overlapping the oil filter. Oil passage arrangement structure of an internal combustion engine. 6. An oil passage arrangement structure for an internal combustion engine according to claim 4, wherein the oil filter inlet oil passage, the oil filter outlet pipe from the oil filter, and the main gallery are connected in a square shape. . 7. The oil passage arrangement structure for an internal combustion engine according to claim 1, wherein a baffle plate is arranged so as to cover the oil filter mounting portion. 8. The internal combustion engine according to claim 1, wherein the height of the oil filter mounting portion is higher than an opening height of an oil pan inlet where oil that has lubricated each part of the internal combustion engine returns to the oil pan. Engine oil passage arrangement structure.

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