Lubricating oil supply structure

Abstract

The present invention provides a lubricating oil supply structure that can suppress foreign object blockage and reduce the flow rate of lubricating oil supplied to parts requiring lubrication with a simple structure. The lubricating oil supply structure (1) includes: an oil supply port (21) provided in a bearing portion (20) supporting a camshaft (30) for supplying lubricating oil between the bearing portion and the camshaft; a first oil passage (11) for allowing lubricating oil supplied from an oil pump to flow to the oil supply port; an inlet port (22) for introducing lubricating oil present between the bearing portion and the camshaft (30); and a second oil passage (12) for supplying lubricating oil introduced from the inlet port to a different supply destination than the bearing portion. The lubricating oil supply structure includes a connecting oil passage (8) formed by the gap between the bearing portion and the camshaft, connecting the first oil passage and the second oil passage. A throttling section (10) is provided in the connecting oil passage to suppress the flow of lubricating oil from the oil supply port to the inlet port.

Description

Technical Field

[0001] This invention relates to a lubricating oil supply structure. Background Technology

[0002] It is known that, from the perspective of preventing blockage by foreign objects, the oil passage for supplying lubricating oil should generally not be smaller than approximately φ1.2–1.5 mm. In this case, if the oil passage diameter is increased to prevent blockage, more lubricating oil would need to be supplied to the parts that require lubrication even with small amounts of lubricating oil. This would increase the pump capacity, increase mechanical losses, and potentially worsen fuel economy. Therefore, it is desirable to reduce the amount of lubricating oil supplied based on the required amount for the intended lubrication point (the part requiring lubrication).

[0003] Patent document 1 discloses the following: Lubricating oil is supplied from an oil pump to an oil filter, and the first oil passage, the second oil passage, and the third oil passage are connected downstream of the oil filter in such a way that the cross-sectional area of ​​the oil passage decreases sequentially.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-174803 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the structure described in Patent Document 1, it is necessary to make three hole shapes corresponding to the first to the third oil passages respectively. In addition to the processing cost, since the first, second and third oil passages extend in different directions, space is also needed to set up the oil passages, making the structure complicated.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a lubricating oil supply structure that can suppress foreign matter blockage and reduce the flow rate of lubricating oil supplied to parts that require lubrication with a simple structure.

[0010] Methods for solving problems

[0011] The lubricating oil supply structure of the present invention comprises: an oil supply port disposed in a bearing portion supporting a shaft, for supplying lubricating oil between the bearing portion and the shaft; a first oil passage connected to the oil supply port for allowing lubricating oil supplied from an oil pump to flow into the oil supply port; an inlet port disposed in the bearing portion for introducing lubricating oil present between the bearing portion and the shaft; and a second oil passage connected to the inlet port for supplying lubricating oil introduced from the inlet port to a different supply destination than the bearing portion. The lubricating oil supply structure is characterized by a connecting oil passage formed by the gap between the bearing portion and the shaft, connecting the first oil passage and the second oil passage, and a throttling portion provided in the connecting oil passage to inhibit the flow of lubricating oil from the oil supply port to the inlet port.

[0012] Alternatively, the bearing surface of the bearing portion may be provided with an oil groove extending circumferentially, the oil supply port may be opened inside the oil groove, the inlet port may be opened in the portion of the bearing surface where the oil groove is not provided, and the connecting oil passage may include the oil groove and the throttling portion, the throttling portion being formed with a gap narrower than the gap between the oil groove and the shaft.

[0013] According to this structure, the flow rate of lubricating oil at the guide inlet can be reduced by using the throttling section, and by supplying lubricating oil to the oil tank from the oil supply port that opens inside the oil tank on the bearing side, the amount of lubricating oil required for the lubrication of the bearing part can be ensured in the oil tank.

[0014] Alternatively, an oil groove extending circumferentially may be provided on the outer peripheral surface of the portion of the shaft supported by the bearing portion, the oil supply port may open at a position in the bearing surface of the bearing portion that is radially opposite to the oil groove, the inlet port may open at a position in the bearing surface that is not radially opposite to the oil groove, and the throttling portion may be formed with a gap narrower than the gap between the oil groove and the bearing surface.

[0015] According to this structure, the flow rate of lubricating oil at the guide inlet can be reduced by using the throttling section, and lubricating oil can be supplied from the oil supply port on the bearing side to the oil groove on the shaft side, thereby ensuring the amount of lubricating oil required for the bearing part in the oil groove.

[0016] Alternatively, the oil supply port and the inlet port may be located at positions where they overlap in the axial direction but differ in the circumferential direction.

[0017] According to this structure, the lubricating oil supply structure has a simple construction, and the design freedom for the configuration of the oil supply port and the inlet port is increased.

[0018] Alternatively, the oil supply port and the inlet port may open at different axial positions.

[0019] According to this structure, the lubricating oil supply structure has a simple construction, and the design freedom for the configuration of the oil supply port and the inlet port is increased.

[0020] Alternatively, the shaft may be a camshaft provided in an internal combustion engine, the portion supported by the bearing portion may be the cam journal of the camshaft, and the different supply destination may be a cam shower that drips lubricating oil onto the cam protrusion of the camshaft.

[0021] According to this structure, the lubricating oil supply mechanism can be applied to the lubrication device of an internal combustion engine. By arranging a cam shower on the downstream side of the camshaft journal, the flow rate of lubricating oil supplied to the cam shower can be reduced.

[0022] Alternatively, the shaft may be a crankshaft of an internal combustion engine, the portion supported by the bearing portion may be a crankshaft journal of the crankshaft, and the different supply destination may be a sprocket that rotates integrally with the crankshaft.

[0023] According to this structure, the lubricating oil supply mechanism can be applied to the lubrication system of an internal combustion engine, and can supply lubricating oil supplied to the crankshaft journal to the sprocket via a connecting oil passage. This reduces the flow rate of lubricating oil supplied to the sprocket.

[0024] Invention Effects

[0025] In this invention, the connecting oil path that connects the first oil path and the second oil path is formed by the gap between the bearing portion and the shaft, thus preventing foreign matter from flowing into the second oil path from the connecting oil path, and having a throttling portion, thus reducing the flow rate of lubricating oil supplied to the second oil path. Attached Figure Description

[0026] Figure 1 This is a structural diagram showing the application of the lubricating oil supply structure of the first embodiment to the lubrication device of an internal combustion engine.

[0027] Figure 2 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the first embodiment.

[0028] Figure 3 This is a perspective view schematically representing a variation of the first embodiment.

[0029] Figure 4 This is a partial cross-sectional view schematically representing a variation of the first embodiment.

[0030] Figure 5 This is a schematic diagram showing the general structure of the lubricating oil supply structure in a variation of the first embodiment.

[0031] Figure 6 It means Figure 5 A sectional view of the AA line section.

[0032] Figure 7 It means Figure 5 A schematic diagram of the structure of the cam cover viewed from direction B.

[0033] Figure 8 This is a structural diagram showing the application of the lubricating oil supply structure of the second embodiment to the lubrication device of an internal combustion engine.

[0034] Figure 9 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the second embodiment.

[0035] Figure 10 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the second embodiment.

[0036] Explanation of reference numerals in the attached figures

[0037] 1. Lubricating oil supply structure;

[0038] 2. Oil pump;

[0039] 3. Camshaft journal;

[0040] 4. Cam shower;

[0041] 5. Oil pan;

[0042] 6. Cylinder head;

[0043] 7. Cam cover;

[0044] 8. Connect the oil circuit;

[0045] 9. Oil tank;

[0046] 10 Throttling section;

[0047] 11. First oil circuit;

[0048] 12. Second oil circuit;

[0049] 21. Oil supply port;

[0050] 22. Import port. Detailed Implementation

[0051] Hereinafter, with reference to the accompanying drawings, the lubricating oil supply structure in embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described below.

[0052] (First Implementation)

[0053] Figure 1This is a structural diagram showing the application of the lubricating oil supply structure of the first embodiment to the lubrication device of an internal combustion engine. Figure 2 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the first embodiment.

[0054] The lubricating oil supply structure 1 in the first embodiment can be applied to the lubrication device 100 of an internal combustion engine. For example... Figure 1 As shown, the lubrication system 100 of the internal combustion engine is a device that uses an oil pump 2 to circulate lubricating oil, supplying lubricating oil to the camshaft journal 3 and the camshaft shower 4. The lubricating oil is supplied to both the camshaft journal 3 and the camshaft shower 4. In this circulation path, the camshaft shower 4 is located downstream of the camshaft journal 3. The camshaft shower 4 is a location where a small amount of lubricating oil is sufficient to meet the required amount.

[0055] Oil pump 2 draws in lubricating oil stored in oil pan 5 and discharges it to the first oil passage 11, which serves as the oil supply passage. The first oil passage 11 is an oil passage through which lubricating oil supplied from oil pump 2 flows to the camshaft journal 3 of camshaft 30. Lubricating oil is supplied to the camshaft journal 3 from the first oil passage 11. Furthermore, the lubricating oil supplied to the camshaft journal 3, after lubricating the camshaft journal 3, is supplied to the cam shower 4. The cam shower 4 drips lubricating oil onto the cam cam lobe (not shown) of camshaft 30. The lubricating oil dripping from the cam shower 4 is supplied to the cam lobe above the cylinder head 6 and then stored in oil pan 5 located at the lower part of the internal combustion engine. When oil pump 2 is driven, the lubricating oil stored in oil pan 5 is drawn in from the suction port of oil pump 2 via an oil filter (not shown) and discharged from the discharge port to the oil supply passage. Alternatively, an oil filter (not shown) may be installed between oil pump 2 and camshaft journal 3.

[0056] The camshaft 30 includes a camshaft journal 3 and cam cams. The camshaft journal 3 is supported by a bearing portion 20. The cam cams are the parts that slide on a rocker arm (not shown), and multiple cam cams are provided on the camshaft 30. Furthermore, the internal combustion engine has two camshafts: a camshaft for intake valves and a camshaft for exhaust valves. In this description, the camshaft for intake valves and the camshaft for exhaust valves are referred to as camshaft 30 without specifically distinguishing between them.

[0057] like Figure 2 As shown, a cam cover 7 is fixed to the upper surface 6a of the cylinder head 6 of the internal combustion engine. A camshaft 30 is rotatably supported by the cylinder head 6 and the cam cover 7. The bearing portion 20 of the camshaft 30 is formed by the cylinder head 6 and the cam cover 7. The cylinder head 6 forms the lower bearing portion. The cam cover 7 forms the upper bearing portion. In this description, the cylinder head 6 and the cam cover 7 are sometimes referred to together as the bearing portion 20. Furthermore, when describing the peripheral structure of the bearing portion 20, the camshaft journal 3 is synonymous with the camshaft 30.

[0058] The lubricating oil supply structure 1 of the first embodiment is a structure provided around the camshaft 30, and includes a connecting oil passage 8 formed by the gap between the camshaft 30 and the bearing portion 20. The connecting oil passage 8 is an oil passage formed by the surface of the part that needs lubrication, and constitutes a flow path connecting the first oil passage 11 and the second oil passage 12. Lubricating oil is supplied to the cam shower 4 via this connecting oil passage 8. Specifically, the path for supplying lubricating oil is formed sequentially from the upstream side to the downstream side as follows: the first oil passage 11, the oil supply port 21, the connecting oil passage 8, the inlet port 22, the second oil passage 12, and the cam shower 4.

[0059] The first oil passage 11 is an oil passage formed in the cylinder head 6, and its downstream side is connected to the oil supply port 21. The oil supply port 21 is an opening formed in the cylinder head 6, which supplies lubricating oil pressurized from the first oil passage 11 to the gap between the camshaft 30 and the bearing portion 20.

[0060] An oil groove 9a extending circumferentially is formed on the bearing surface 20a of the cylinder head 6, which serves as the lower bearing portion. Similarly, an oil groove 9b extending circumferentially is formed on the bearing surface 20b of the cam cover 7, which serves as the upper bearing portion. The oil grooves 9a of the cylinder head 6 and 9b of the cam cover 7 form a series. The oil groove 9 as a whole has a structure that extends only a portion of the circumferential direction, rather than the entire circumference. An oil supply port 21 opens inside the oil groove 9a provided on the bearing surface 20a of the cylinder head 6. Lubricating oil is supplied to the interior of the oil groove 9 from the oil supply port 21.

[0061] The connecting oil passage 8 is an oil passage that allows lubricating oil to flow between the oil supply port 21 and the inlet port 22, and it connects the first oil passage 11 and the second oil passage 12. This connecting oil passage 8 is configured to include an oil groove 9 and a throttling section 10. The oil passage formed by the oil groove 9 is formed by the gap between the bottom surface of the oil groove 9 and the outer peripheral surface 31 of the camshaft journal 3. In the circumferential direction of the bearing portion 20, the throttling section 10 is arranged between the inlet port 22 and the oil groove 9. That is, the oil supply port 21 and the inlet port 22 are arranged at positions that overlap axially but differ circumferentially.

[0062] The throttling section 10 is an oil passage formed by the gap between the bearing surface 20b of the cam cover 7 (which serves as the upper bearing section) and the outer peripheral surface 31 of the camshaft journal 3. This throttling section 10 has a structure that inhibits the flow of lubricating oil from the oil supply port 21 to the guide inlet 22. For example... Figure 2 As shown, the radial clearance formed by the throttling section 10 is narrower than the radial clearance formed by the oil groove 9. Therefore, the throttling section 10 makes the cross-sectional area of ​​the oil passage smaller than the cross-sectional area of ​​the oil passage where the oil groove 9 is provided, and functions as a part for throttling the flow rate of lubricating oil.

[0063] Furthermore, since the connecting oil passage 8 is formed by the gap between the bearing surface 20b and the shaft surface, it has the functions of foreign matter discharge and sealing. Therefore, when the diameters of the first oil passage 11 and the second oil passage 12 are formed to be approximately φ1.2 to 1.5 mm to suppress foreign matter blockage, the throttling section 10 provided in the connecting oil passage 8 is formed to be a flow path (narrow flow path) that is thinner than the minimum diameter of 1.2 mm. For example, the throttling section 10 is an oil passage formed by a gap of tens of μm.

[0064] The inlet 22 is an opening for introducing lubricating oil, which exists between the outer peripheral surface 31 of the camshaft journal 3 and the bearing surface of the bearing portion 20, into the second oil passage 12. This inlet 22 opens into the bearing surface 20b of the cam cover 7. More specifically, the inlet 22 opens into the portion of the bearing surface 20b of the cam cover 7 where the oil groove 9b is not formed. Lubricating oil can flow through this inlet 22 to a different supply destination than the camshaft journal 3.

[0065] The second oil passage 12 is formed in the cam cover 7 and is connected to the inlet 22 on its upstream side. A cam shower pipe 4a, forming the cam shower 4, is connected to the downstream side of the second oil passage 12. The cam shower pipe 4a is located on the upper part of the cam cover 7. The cam shower 4 has multiple lubricating oil supply ports 4b. The supply ports 4b are located above the cam protrusion of the camshaft 30 and open downwards. The lubricating oil introduced into the second oil passage 12 from the inlet 22 flows upwards within the cam cover 7 and is supplied to the cam shower 4. The lubricating oil supplied to the cam shower 4 drips from the supply ports 4b and is supplied to the cam protrusion of the camshaft 30.

[0066] As explained above, in the first embodiment, lubricating oil can be supplied to the cam shower 4 via the connecting oil passage 8 formed by the gap between the bearing surface of the bearing portion 20 and the outer peripheral surface 31 of the camshaft journal 3. Furthermore, since the gap between the bearing portion 20 and the camshaft 30 has a foreign matter discharge and sealing function, unlike a typical oil passage, even a narrow flow path can suppress foreign matter blockage. Therefore, by providing a throttling section 10 in this connecting oil passage 8, the flow rate of lubricating oil supplied to the cam shower 4, which is a destination requiring a small amount, can be reduced.

[0067] Furthermore, in the first embodiment, it is sufficient to provide a connecting oil passage 8 formed by the gap between the bearing portion 20 and the cam journal 3 on the upstream side of the cam shower 4, and to form a throttling portion 10 in a part of the connecting oil passage 8. Therefore, according to the first embodiment, compared with the conventional structure that forms multiple oil passages with different cross-sectional areas, it is possible to suppress foreign matter blockage and reduce the flow rate of lubricating oil with a simple structure.

[0068] Another existing construction is to place the inlet 22 of the second oil passage 12 within the oil groove 9b of the cam cover 7. Compared to this existing construction, in the first embodiment, only the location of the inlet 22 is changed from inside the oil groove 9b to a portion where the oil groove 9b is not located, thus reducing manufacturing costs.

[0069] Furthermore, by using the throttling section 10 to suppress the flow of lubricating oil, the minimum required amount of lubricating oil can be supplied to the cam shower 4, thus reducing the capacity of the oil pump 2 and reducing wasted work. This improves fuel economy in the internal combustion engine. Moreover, when more lubricating oil is supplied than required, the rate of air bubbles in the oil increases due to oil agitation. However, in the first embodiment, by suppressing the supply of wasted oil, the flow rate of the lubricating oil is reduced, thereby lowering the rate of air bubbles in the oil. Therefore, according to the first embodiment, the excess capacity of the oil pump, which takes into account the drop in supply pressure to the hydraulic equipment caused by air bubbles, can be reduced, further reducing the capacity of the oil pump 2.

[0070] Furthermore, in the first embodiment, the structure of the connecting oil passage 8 including the oil groove 9 was described, but the present invention is not limited thereto. That is, the connecting oil passage 8 may be constructed as long as it includes a throttling section 10 formed by the gap between the bearing surface and the outer peripheral surface of the shaft, and it may not necessarily include the oil groove 9. In short, it is also possible to have a lubricating oil supply structure 1 that includes the connecting oil passage 8 without the oil groove 9 in an oil passage structure that passes through the bearing section 20, which serves as a part for discharging and sealing foreign matter.

[0071] Furthermore, in the first embodiment, an example of a lubrication device 100 applied to an internal combustion engine was described, but the present invention is not limited thereto. That is, in a device that supplies lubricating oil to multiple supply destinations using an oil pump, it is sufficient to provide a connecting oil passage 8 composed of a shaft and a bearing section in the middle of the path that supplies lubricating oil to the part where the amount of lubricating oil required for lubrication is relatively small.

[0072] (A variation of the first embodiment)

[0073] Reference Figures 3-7 A variation of the first embodiment will now be described. In this variation, the lubricating oil supply structure 1A has an oil groove provided on the camshaft 30 side.

[0074] like Figure 3 , Figure 4As shown, in this modified example, an oil groove 32 extending circumferentially is formed on the outer peripheral surface 31 of the camshaft journal 3. The oil groove 32 is an annular groove forming the entire circumference of the outer peripheral surface 31. Furthermore, the inlet 22 is positioned at a different axial position than where the oil groove 32 is located. Therefore, an axially extending throttling portion 10A can be formed between the oil groove 32 and the inlet 22. Figure 6 (As shown).

[0075] like Figure 5 As shown, the oil supply port 21 opens on the bearing surface 20b of the cam cover 7. The opening portion of the oil supply port 21 is located radially opposite to the oil groove 32 of the cam journal 3 in the bearing surface 20b. That is, the oil supply port 21 of the cam cover 7 is positioned axially overlapping with the oil groove 32 of the cam journal 3. Thus, the oil supply port 21 opens into the oil groove 32. Furthermore, the first oil passage 11 has a structure that connects the oil passage formed in the cylinder head 6 with the oil passage 7a formed in the cam cover 7. Figure 7 As shown, the oil passage 7a is a straight groove formed on the lower surface 7b of the cam cover 7.

[0076] like Figure 6 As shown, the connecting oil passage 8A is configured to include an oil groove 32 and a throttling section 10A. The oil groove 32 is formed in the portion of the outer peripheral surface 31 opposite to the bearing surface 20b, and has a predetermined width in the axial direction. The inlet 22 opens at a position different from the axial position of the oil groove 32. The throttling section 10A is the part in the connecting oil passage 8A that forms a flow path between the oil groove 32 and the inlet 22. That is, the oil supply port 21 and the inlet 22 are arranged at positions that are different in both the axial and circumferential directions.

[0077] In detail, the throttling section 10A is formed by a radial clearance between the adjusting groove 23 formed on the bearing surface 20b and the outer peripheral surface 31 of the camshaft journal 3. The adjusting groove 23 is a shallow groove that adjusts the flow rate of lubricating oil flowing through the guide inlet 22. For example, the depth of the adjusting groove 23 is shallower than the depth of the oil groove 32. Furthermore, the adjusting groove 23 is located at a position that is not radially opposite to the oil groove 32. That is, the axial position of the adjusting groove 23 is different from the axial position of the oil groove 32. As a result, the oil passage formed by the radial clearance between the bottom surface of the adjusting groove 23 and the outer peripheral surface 31 becomes a narrower flow path than the oil passage formed by the radial clearance between the bottom surface of the oil groove 32 and the bearing surface 20b.

[0078] Furthermore, the second oil passage 12 is formed in an inclined shape relative to the height direction. By increasing this inclination angle, the second oil passage 12 can be formed at a location where the surface pressure from the camshaft journal 3 acting on the cam cover 7 is low. By providing the second oil passage 12 in the portion of the cam cover 7 where the surface pressure from the camshaft journal 3 is low, durability is improved.

[0079] like Figure 7 As shown, the adjustment groove 23 is formed on the bearing surface 20b of the cam cover 7. More specifically, the inlet 22 and the adjustment groove 23 are arranged at a position where they overlap in the circumferential direction. The adjustment groove 23 is formed in a portion of the bearing surface 20b in the circumferential direction. In this way, when the flow rate of lubricating oil in the oil passage cross-sectional area formed by the radial clearance between the bearing surface 20b of the cam cover 7 and the outer peripheral surface 31 of the camshaft journal 3 is low, the flow rate of lubricating oil flowing into the inlet 22 can be increased by providing the adjustment groove 23 on the bearing surface 20b. The inlet 22 opens in the outer peripheral surface 31 of the camshaft journal 3 at a position that is radially opposite to the portion where the oil groove 32 is not provided.

[0080] Furthermore, a branch oil passage 13, which branches off from the second oil passage 12, is connected to the oil passage formed by the oil groove 32 of the camshaft 30. This branch oil passage 13 connects to the downstream side of the oil passage formed by the oil groove 32 and supplies lubricating oil to a different destination than the cam shower 4. In this modified example, the oil supply port 21 and the inlet port 22 need only be located at least in different axial positions, and do not necessarily need to be located in different circumferential positions.

[0081] (Second Implementation)

[0082] Figure 8 This is a structural diagram showing the application of the lubricating oil supply structure of the second embodiment to the lubrication device of an internal combustion engine. Figure 9 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the second embodiment. Figure 10 This is a schematic diagram showing the general structure of the lubricating oil supply structure in the second embodiment. Figure 10 The diagram illustrates the representation. Figure 9 A cross-sectional view along the CC line. Furthermore, in the description of the second embodiment, descriptions of structures identical to those in the first embodiment described above are omitted, and their reference numerals are used instead.

[0083] like Figure 8 As shown, in the lubrication device 100 of the second embodiment, engine oil pumped from the oil pump 2 is supplied to the crankshaft 51 and the fuel injector 52. The destinations for the lubricating oil supply include the crankshaft 51 and the fuel injector 52. In this circulation path, the fuel injector 52 is arranged downstream of the crankshaft 51. The fuel injector 52 is a location where a small amount of lubricating oil is sufficient to achieve the required amount.

[0084] Oil pump 2 discharges lubricating oil into the supply oil circuit and supplies lubricating oil to the main oil passage 14 and the first oil passage 15, which are connected to the supply oil circuit. The main oil passage 14 is located in the cylinder block 53. Figure 9 The oil passage (shown) allows lubricating oil supplied to multiple destinations to flow. The first oil passage 15 directs lubricating oil supplied from the oil pump 2 to the crankshaft journal 51a of the crankshaft 51. Figure 10 (As shown) is the oil passage through which lubricating oil flows. The main oil passage 14 is connected to the first oil passage 15, from which lubricating oil is supplied to the crankshaft 51. Furthermore, the lubricating oil supplied to the crankshaft 51, after lubricating the crankshaft 51, is supplied to the fuel injector 52 via the second oil passage 16. The fuel injector 52 supplies oil to the sprocket 55 of the timing chain (…). Figure 10 (As shown) Lubricating oil is injected. The lubricating oil injected from the injector 52 is supplied to the sprocket 55, which rotates integrally with the crankshaft 51, and then stored in the oil pan 5 located at the bottom of the internal combustion engine.

[0085] like Figure 9 , Figure 10 As shown, the lubricating oil supply structure 1B of the second embodiment is a structure provided around the crankshaft 51, and includes a connecting oil passage 8B formed by the gap between the crankshaft 51 and the bearing portion 20A. The connecting oil passage 8B constitutes a flow path connecting the first oil passage 15 and the second oil passage 16. Lubricating oil is supplied to the injector 52 via this connecting oil passage 8B. Specifically, the path for supplying lubricating oil is formed sequentially from the upstream side to the downstream side as follows: main oil passage 14, first oil passage 15, oil supply port 21, connecting oil passage 8B, inlet port 22, second oil passage 16, and injector 52.

[0086] The first oil passage 15 is an oil passage formed in the cylinder block 53, and its downstream side is connected to the oil supply port 21. The oil supply port 21 is an opening formed in the cylinder block 53, which supplies lubricating oil pressurized from the first oil passage 15 to the gap between the crankshaft 51 and the bearing section 20A.

[0087] A first main bearing 53a is provided in the cylinder block 53, which serves as the upper bearing section. A second main bearing 54a is provided in the trapezoidal frame 54, which serves as the lower bearing section. Both the first main bearing 53a and the second main bearing 54a are semi-divided cylindrical metal parts. An oil groove 9A extending circumferentially is formed on the bearing surface 20c of the first main bearing 53a. On the other hand, no oil groove is provided on the bearing surface 20d of the second main bearing 54a. An oil supply port 21 opens inside the oil groove 9A on the bearing surface 20c on the cylinder block 53 side. Lubricating oil is supplied to the inside of the oil groove 9A from the oil supply port 21.

[0088] The connecting oil passage 8B is an oil passage that allows lubricating oil to flow between the oil supply port 21 and the inlet port 22, and it connects the first oil passage 15 and the second oil passage 16. This connecting oil passage 8B includes an oil groove 9A and a throttling section 10A. The oil passage formed by the oil groove 9A is formed by the gap between the bottom surface of the oil groove 9A and the outer peripheral surface 51b of the crankshaft journal 51a. In the circumferential direction of the bearing portion 20A, the throttling section 10A is positioned between the inlet port 22 and the oil groove 9A. That is, the oil supply port 21 and the inlet port 22 are positioned at different axial and circumferential locations.

[0089] The throttling section 10A is an oil passage formed by the gap between the bearing surface 20c on the cylinder block 53 side, which serves as the upper bearing section, and the outer peripheral surface 51b of the crankshaft journal 51a. This throttling section 10A has a structure that inhibits the flow of lubricating oil from the oil supply port 21 to the guide inlet 22. For example... Figure 10 As shown, the radial clearance formed by the throttling section 10A is narrower than the radial clearance formed by the oil groove 9A. Therefore, the throttling section 10A makes the cross-sectional area of ​​the oil passage smaller than the cross-sectional area of ​​the oil passage where the oil groove 9A is provided, thus functioning as a part for throttling the flow rate of lubricating oil.

[0090] Furthermore, since the connecting oil passage 8B is formed by the gap between the bearing surface 20c on the cylinder block 53 side and the shaft surface, it has the functions of foreign matter discharge and sealing. Therefore, when the diameters of the first oil passage 15 and the second oil passage 16 are formed to be approximately φ1.2 to 1.5 mm to suppress foreign matter blockage, the throttling section 10A provided in the connecting oil passage 8B is formed to be a flow path (narrow flow path) that is thinner than this minimum diameter of 1.2 mm. For example, the throttling section 10A is an oil passage formed by a gap of tens of μm.

[0091] The inlet 22 is an opening in the second oil passage 16 through which lubricating oil existing between the outer peripheral surface 51b of the crankshaft journal 51a and the bearing surface of the bearing portion 20A is introduced. This inlet 22 opens onto the bearing surface 20c of the first main bearing 53a on the cylinder block 53 side. More specifically, the inlet 22 opens onto the portion of the bearing surface 20c of the first main bearing 53a where the oil groove 9A is not formed. That is, the axial position of the inlet 22 is different from the axial position of the oil groove 9A. Lubricating oil can flow through this inlet 22 to a destination different from the crankshaft journal 51a.

[0092] The second oil passage 16 is an oil passage formed in the cylinder block 53, and its upstream side is connected to the inlet 22. A fuel injector 52 is connected to the downstream side of the second oil passage 16. The fuel injector 52 is positioned above the sprocket 55 of the timing chain. The fuel injector 52 has a supply port 52a for injecting lubricating oil. The supply port 52a is positioned above the sprocket 55 and opens downwards. Lubricating oil introduced into the second oil passage 16 from the inlet 22 is injected through the supply port 52a of the fuel injector 52 and supplied to the sprocket 55.

[0093] As explained above, in the second embodiment, lubricating oil can be supplied to the injector 52 via the connecting oil passage 8B formed by the gap between the bearing surface of the bearing portion 20A and the outer peripheral surface 51b of the crankshaft journal 51a. Furthermore, since the gap between the bearing portion 20A and the crankshaft 51 has a foreign matter discharge and sealing function, unlike a typical oil passage, even a narrow flow path can suppress foreign matter blockage. Therefore, by providing a throttling section 10A in this connecting oil passage 8B, the flow rate of lubricating oil supplied to the injector 52, which is a destination with a small required quantity, can be reduced.

[0094] Furthermore, in the second embodiment, a connecting oil passage 8B formed by the gap between the bearing portion 20A and the crankshaft journal 51a is provided on the upstream side of the oil injector 52, and a throttling portion 10A is formed in a part of this connecting oil passage 8B. As a conventional construction, a configuration in which the inlet 22 of the second oil passage 16 is opened inside the oil groove 9A of the first main bearing 53a can be cited. Compared with this conventional structure, in the second embodiment, only the position of the inlet 22 is changed from inside the oil groove 9A to a portion where the oil groove 9A is not provided, thus reducing manufacturing costs. Therefore, according to the second embodiment, foreign matter blockage and reduced lubricating oil flow can be suppressed with a simple construction.

[0095] Furthermore, by using the throttling section 10A to suppress the flow of lubricating oil, the minimum required amount of lubricating oil can be supplied to the injector 52, thereby reducing the capacity of the oil pump 2 and reducing wasted energy. Therefore, according to the second embodiment, the remaining capacity of the oil pump, which takes into account the drop in supply pressure to the hydraulic equipment caused by air bubbles, can be reduced, and the capacity of the oil pump 2 can be further reduced.

[0096] Furthermore, in the second embodiment, the structure of the connecting oil passage 8B including the oil groove 9A has been described, but the present invention is not limited thereto. That is, the connecting oil passage 8B may or may not include the oil groove 9A, as long as it includes a throttling section 10A formed by the gap between the bearing surface and the outer peripheral surface of the shaft. In short, it is also possible to have a lubricating oil supply structure 1B that does not include the oil groove 9A in the oil passage structure that passes through the bearing section 20A, which has the function of discharging and sealing foreign objects.

Claims

1. A lubricating oil supply structure comprising: an oil supply port provided to a bearing portion that supports a shaft, and supplying lubricating oil between the bearing portion and the shaft; a first oil passage that is connected to the oil supply port, and makes lubricating oil supplied from an oil pump flow to the oil supply port; a guide port provided to the bearing portion, and guiding lubricating oil present between the bearing portion and the shaft; and a second oil passage that is connected to the guide port, and supplies lubricating oil guided from the guide port to a supply destination different from the bearing portion, characterized in that the lubricating oil supply structure comprises a connection oil passage that is formed by a gap between the bearing portion and the shaft, and connects the first oil passage and the second oil passage, a throttle portion that suppresses flow of lubricating oil from the oil supply port to the guide port is provided in the connection oil passage, an oil groove that extends in a circumferential direction is provided to an outer peripheral surface of a portion of the shaft that is supported by the bearing portion, the oil supply port is opened at a position in the bearing surface of the bearing portion that is opposite to the oil groove in a radial direction, the guide port is opened at a position in the bearing surface that is not opposite to the oil groove in the radial direction, the throttle portion is formed as a gap that is narrower than a gap between the oil groove and the bearing surface, the throttle portion is formed by a radial gap between an adjustment groove formed in the bearing surface and the outer peripheral surface of the shaft, the adjustment groove is formed at a part of the circumferential direction in the bearing surface, adjusts a flow rate of lubricating oil that flows to the guide port, a depth of the adjustment groove is formed shallower than a depth of the oil groove, and the adjustment groove is provided at a position that is not opposite to the oil groove in the radial direction, whereby an oil passage formed by a radial gap between a bottom surface of the adjustment groove and the outer peripheral surface of the shaft becomes a flow path that is narrower than an oil passage formed by a radial gap between a bottom surface of the oil groove and the bearing surface, and the guide port and the adjustment groove are arranged at a position where circumferential positions overlap.

2. The lubricating oil supply structure according to claim 1, characterized in that the oil supply port and the guide port are opened at positions different in an axial direction.

3. The lubricating oil supply structure according to claim 1, characterized in that the shaft is a camshaft provided to an internal combustion engine, the portion supported by the bearing portion is a cam journal of the camshaft, and the different supply destination is a cam shower that drips lubricating oil to a cam lobe of the camshaft.

4. The lubricating oil supply structure according to claim 1, characterized in that the shaft is a crankshaft of an internal combustion engine, the portion supported by the bearing portion is a crank journal of the crankshaft, and the different supply destination is a sprocket that rotates integrally with the crankshaft. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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