JP5747500B2 - Engine oil circulation device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an engine oil circulation device, and in particular, an engine including a bypass passage branched from a branch supply oil passage for supplying oil to an oil supply target portion and an exhaust port side oil passage provided in the vicinity of an exhaust port of a cylinder head. The present invention relates to an oil circulation device.

  Conventionally, an engine oil circulation device supplies oil discharged from an oil pump to a plurality of lubrication target parts such as a crank journal and a cam journal mounted on a cylinder block and a cylinder head, and lubricates and cools each lubrication target part. Had gone. This oil is sucked from an oil pan by an oil pump, led to the main gallery, and then supplied to each oil supply target portion through a plurality of branch supply oil passages branched from the main gallery. The oil that has been lubricated and cooled in each oil supply target portion is collected and returned to the oil pan through the head side drain oil passage and the block side drain oil passage.

  Oil during warm-up of the engine has a low temperature and its viscosity is high, so the cooling water temperature of the engine usually rises, and after heat exchange with this heated cooling water, the oil is heated to an appropriate temperature. Until then, warm-up operation was required. Therefore, until the oil reaches an appropriate temperature, each oil supply target portion operates in a state where the mechanical resistance is high, which causes deterioration of the fuel consumption of the engine. Therefore, the temperature of the oil is increased by using the exhaust gas of the engine.

  The engine heat exchange system described in Patent Document 1 includes an exhaust manifold, a catalytic converter installed on the downstream side of the exhaust manifold, a main exhaust pipe connected to the downstream side of the catalytic converter, and a downstream of the catalytic converter. A sub-exhaust pipe branched from the side and having a downstream end connected to the main exhaust pipe, and a heat exchanger installed in the middle of the sub-exhaust pipe and capable of raising the temperature of oil flowing to the oil filter side by the heat of the exhaust gas And a switching valve provided in the sub exhaust pipe and capable of adjusting the flow rate of the exhaust gas flowing through the sub exhaust pipe. In this heat exchange system, the switching valve adjusts the flow rate of the exhaust gas flowing through the main exhaust pipe and the sub exhaust pipe according to the operating state of the engine, and raises the oil temperature to an appropriate temperature.

  The piston oil jet is installed in the cylinder block among the plurality of oil supply target portions, and injects cooling oil to the back surface of the piston crown portion that receives the explosion gas pressure of the combustion gas. The oil jet includes a valve member having a check valve therein, an oil injection nozzle, a case portion, and the like. The check valve is opened when the oil pressure is higher than a predetermined oil pressure, and is formed so that cooling oil is injected from the oil injection nozzle.

JP 2005-226474 A

  In the engine heat exchange system of Patent Document 1, the switching valve is controlled so that the exhaust gas flows through the sub-exhaust pipe when the engine is in a warm air state, so that heating of the oil is promoted regardless of the cooling water temperature of the engine. It is possible to reduce the mechanical resistance of each refueling target part and to improve the fuel consumption of the engine. However, in this heat exchange system, since the heat exchanger is arranged in the middle of the sub exhaust pipe, the flow resistance of the exhaust gas flowing in the sub exhaust pipe increases, and as a result, the fuel consumption of the engine may be deteriorated. is there. In addition, as described above, it is necessary to change the structure of the exhaust manifold, newly install a heat exchanger, and the like, which may cause a change in the exhaust system layout and increase the manufacturing cost.

  Further, in the heat exchange system, since oil is supplied to a so-called cooling oil supply target portion that does not require oil supply in a warm air state as well as other oil supply target portions, There is a possibility that warming up of the refueling target part is delayed. In particular, the flow rate of oil injected from the piston oil jet is significantly increased when the engine is in a warm-up state compared to the flow rate after the warm-up state. In other words, when the oil temperature is low, the oil viscosity increases, and the oil pressure in the branch supply oil passage that communicates with the oil jet rises rapidly due to the decrease in the bearing clearance area of each journal part. The oil flow rate injected from the nozzle increases. Therefore, when the engine is in a warm-up state, a large amount of low-temperature oil is injected onto the back surface of the piston crown portion, so that the piston is excessively cooled, resulting in deterioration of engine combustibility and piston warm-up delay.

  An object of the present invention is to provide an engine oil circulation device that can raise the oil temperature using the heat of the exhaust port without causing an increase in exhaust resistance or a change in the exhaust system layout. It is to provide an oil circulation device for an engine that can promote the engine.

An oil circulation device for an engine according to claim 1 includes a plurality of oil supply target portions provided in a cylinder block and a cylinder head, an oil pump that sucks oil stored in an oil pan and discharges the oil to a main oil passage, and the main oil passage. A multi-cylinder having a plurality of branch oil supply passages that branch from an oil passage and supply oil to the plurality of oil supply target portions, and a plurality of head side drain oil passages that can return oil from the plurality of oil supply target portions to an oil pan. In the engine oil circulation device, the bypass passage branched from any one of the plurality of branch oil supply passages, and is formed over an upper position of the multi-cylinder exhaust port of the cylinder head . and the downstream oil passage, and said multi-cylinder multiple exhaust port side oil passage Ru is directed annular to be formed and the oil to the plurality of head-side drain oil passage so as to surround the exhaust port A bypass passage and a plurality of branch oil passages for oil respectively dispensed from the downstream oil passage to a plurality of exhaust ports top of the exhaust port side oil passage, the engine is provided in the bypass passage is opened when the warm-up state And a valve means that closes when the warm-up is completed, and has a plurality of block-side drain oil passages that are connected to the plurality of head-side drain oil passages and return oil to an oil pan, and the exhaust port-side oil passages are An oil guiding section is provided for guiding the oil that has been refluxed through to the temperature rising oil request section where the heated oil is required, and the oil guiding section surrounds the inlet of the oil pump and is housed inside the oil pan. And an inner oil pan that is made to return to the inner oil pan .

  This engine's oil circulation device can direct heat-receiving oil to a position near the exhaust port by installing a bypass passage, which is a dedicated oil warm-up pipe, so that there is no change in the exhaust system structure or exhaust layout. Heat exchange with gas is possible. As a result, when the engine is in a warm-up state, the oil temperature can be raised quickly regardless of the engine coolant temperature, and the mechanical resistance of the refueling target portion can be reduced.

According to a second aspect of the present invention, in the first aspect of the invention, the oil guiding portion is configured to collect a plurality of introduction portions that introduce oil from downstream ends of the plurality of block-side drain oil passages, and the plurality of introduction portions. In addition, it is characterized by having a lead-out portion for leading the introduced oil to a position near the suction port of the oil pump .
According to a third aspect of the present invention, in the first or second aspect of the present invention, the cylinder block includes an oil jet capable of injecting oil to the piston, and the bypass passage branches from a branch oil supply passage that supplies oil to the oil jet. The amount of oil supplied to the oil jet is limited when the valve means is opened .

According to the first aspect of the present invention, since the exhaust system structure and the exhaust layout are not changed, the manufacturing cost can be suppressed without increasing the flow resistance of the exhaust gas while ensuring the oil temperature rising function. it can. Since the oil can be directed from the branch oil supply path of the oil supply target part to be supplied with oil to the position near the exhaust port among the plurality of branch oil supply paths, the oil is used as a heat receiving medium for the exhaust gas when the engine is warm. It can be used, and it is possible to prevent overcooling of the oil supply target portion by the oil, to prevent a delay in warming of the oil supply target portion, to promote warming up of the engine, and as a result, to improve the fuel efficiency of the engine.
Further, the bypass passage that can receive heat from the exhaust gas can be lengthened, and the amount of heat that can be received from the exhaust gas can be increased. Furthermore, the oil whose temperature has been raised by the oil guiding section can be collected in the temperature rising oil request section, and early warming of the engine can be promoted.
In addition, the oil heated by the oil guiding section can be collected in the inner oil pan, the temperature of the limited oil can be raised quickly and recirculated by the oil pump, and early warming of the engine can be promoted.

According to the second aspect of the present invention, the oil heated by the oil guiding portion can be collected in the vicinity of the suction port of the oil pump, and can be recirculated by the oil pump without lowering the temperature of the oil. Warm up can be promoted .

According to the invention of claim 3 , when the engine is in the warm-up state, the cooling performance of the piston is maintained, and when the engine is in the warm-up state, the amount of low-temperature oil injected to the piston is reduced, and the piston Early warm-up and improved engine combustibility .

1 is an overall configuration diagram of an engine oil circulation device according to Embodiment 1 of the present invention. It is a longitudinal cross-sectional view parallel to the cylinder row direction of an engine. It is a longitudinal cross-sectional view orthogonal to the cylinder row direction of an engine. It is the figure which looked at the cylinder block from the top. It is the figure which looked at the cylinder head from the bottom. It is the figure which looked at the cylinder head from the exhaust port side. It is the VI-VI sectional view taken on the line of FIG. FIG. 3 is a view corresponding to FIG. 2 illustrating a modification of the first embodiment. FIG. 9 is a view corresponding to FIG. 2 and showing another modification of the first embodiment. It is a 2 equivalent diagram according to the reference technique. FIG. 4 is a view corresponding to FIG. 3 according to the reference technique . It is a 11 corresponding view of a modified example of a reference technology.

  Hereinafter, modes for carrying out the present invention will be described based on examples. In the following description, the left side in FIG.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1-7, the oil circulation apparatus 1 of a present Example circulates oil with respect to the multicylinder engine of a vehicle, for example, a horizontal in-line 4 cylinder gasoline reciprocating engine E. As shown in FIG.
The engine E includes oil pans 2a and 2b, a cylinder block 3, a cylinder head 4 and the like, and the cylinder row direction is orthogonal to the traveling direction of the vehicle and the intake side camshaft is in front of the traveling direction of the vehicle. It is installed in the engine room.

  As shown in FIGS. 1 to 3, the outer oil pan 2 a is formed in a concave shape and configured to store oil circulating in the engine E. The upper end portion of the outer oil pan 2 a is connected to the lower end portion of the cylinder block 3. An inner oil pan 2b having a smaller storage capacity than the outer oil pan 2a is provided inside the outer oil pan 2a. The inner oil pan 2 b is formed in a concave shape and is connected to the lower end portion of the cylinder block 3, similarly to the outer oil pan 2 a.

  An on-off valve 5 is installed below the inner oil pan 2b. The on-off valve 5 is configured to be closed when the engine E is in a warm-up state, and to open when the engine E is warmed up, for example, when the coolant temperature of the engine E is raised to 80 to 90 ° C. ing. As a result, the oil stored in the outer oil pan 2a is separated from the oil stored in the inner oil pan 2b before the warming up of the engine E is completed, and only when the warming up of the engine E is completed, the oil is stored via the opening / closing valve 5. It can flow into the oil pan 2b.

  As shown in FIGS. 1 and 3, the cylinder block 3 includes an oil pump 6, four pistons 7, four oil jets 8, a crankshaft 9, and the like. The oil pump 6 is constituted by an electric variable displacement oil pump whose lower limit of discharge pressure is set to 150 kPa, and is configured to be able to discharge pressurized oil to the main gallery 31 (main oil passage). The oil pump 6 includes an oil strainer 6a. The oil strainer 6 a is formed in a cylindrical shape, and its downstream end is connected to the suction portion of the oil pump 6. The upstream end of the oil strainer 6a is disposed in the inner oil pan 2b, and the suction port of the oil strainer 6a is disposed opposite to the bottom of the inner oil pan 2b. A mechanical fixed displacement pump can be applied instead of the electric oil pump 6.

  Each piston 7 includes a piston crown portion, a pair of skirt portions, a pair of pin boss portions, and the like. The piston 7 is formed in a bottomed cylindrical shape that opens downward. Each piston 7 is fitted into the cylinder bore 3a of each cylinder, and is configured to be able to reciprocate up and down in the cylinder bore 3a. Each oil jet 8 is equipped at the lower part of the exhaust side of the cylinder bore 3a of each cylinder. The oil jet 8 has a check valve 8a therein. When each oil jet 8 is mounted on the cylinder block 3 and the oil supply pressure is a predetermined value, for example, 0.2 MPa or more, the check valve 8a is opened to cool the back surface of the piston crown of each piston 7. Oil is injected.

  The crankshaft 9 includes five shaft portions, four crankpin portions 9b, a crankshaft oil passage 9a (see FIG. 1), and the like. The shaft portion is formed coaxially with the rotational axis of the crankshaft 9. The shaft is pivotally supported via a main journal 10 formed in the cylinder block 3. The four crankpin portions 9b are arranged so that the rotation locus thereof is coaxial with the rotation axis of the crankshaft 9, and are formed at positions eccentric from the shaft portion. The crank pin portion 9 b pivotally supports each connecting rod 12 via a pin journal 11. Therefore, when the engine E is operating, the lubricating oil flows from the main journal 10 to the pin journal 11 through the crankshaft oil passage 9a.

  As shown in FIGS. 1 to 4, the cylinder block 3 includes a main gallery 31 (main oil passage), a plurality of branch oil supply passages 32 and 33 branched from the main gallery 31, and four block side drain oil passages. 34, an oil guiding portion 35, and the like are formed. The main gallery 31 is formed on the intake side wall of the cylinder block 3 and is connected to the discharge port of the oil pump 6. The first branch oil supply path 32 has an upstream end connected to the main gallery 31 and a downstream end connected to the main journal 10. Thereby, the lubricating oil supplied from the main gallery 31 via the first branch oil supply passage 32 is supplied to each shaft portion of the crankshaft 9 by the main journal 10. Further, the oil supplied to each shaft portion is supplied to the pin journal 11 through the oil passage 9a in the crankshaft. The oil supplied to the main journal 10 and the pin journal 11 is dropped into the inner oil pan 2b and refluxed after finishing the lubrication of the shaft portion and the crankpin portion.

  The second branch oil supply path 33 has an upstream end connected to the main gallery 31 and a downstream end connected to the check valve 8 a of the oil jet 8. Thereby, the cooling oil supplied from the main gallery 31 via the second branch oil supply passage 33 is supplied to the injection nozzle of the oil jet 8 via the check valve 8a. The oil sprayed from the spray nozzle to the back surface of the piston crown is dropped into the inner oil pan 2b and refluxed after cooling of the piston 7 is completed.

  As shown in FIGS. 2 to 4, each block-side drain oil passage 34 is formed on the exhaust side wall portion of the cylinder block 3 so as to extend in the vertical direction from the upper end to the lower end of the cylinder block 3. Each block-side drain oil passage 34 is arranged at the center position in the cylinder row direction with respect to the cylinder bore 3a of each cylinder.

  As shown in FIGS. 2 and 3, the oil guiding portion 35 includes four introduction portions 35 a and one lead-out portion 35 b. The four introduction portions 35 a are connected to the downstream end portions of the four block side drain oil passages 34 at the upstream end portions, respectively. The lead-out part 35b is formed by collecting downstream portions of the four introduction parts 35a. The derivation | leading-out part 35b is extended so that the oil strainer 6a may be approached from the gathering part of the downstream part of each introduction part 35a. The outlet of the outlet 35b is disposed in the vicinity of the inlet of the oil strainer 6a within the oil surface. As a result, the reflux oil that has flowed through each block-side drain oil passage 34 is gathered by the oil guide portion 35 and led out from the lead-out port of the lead-out portion 35b to a position near the suction port of the oil strainer 6a.

As shown in FIG. 1, the cylinder head 4 includes an intake side camshaft (not shown), an exhaust side camshaft (not shown), a plurality of variable valve timing mechanisms (VVT) 13 and the like.
Both camshafts are pivotally supported via a plurality of cam journals 14 formed in the cylinder head 4. A rotational driving force is transmitted from both crankshafts to the camshafts, and intake and exhaust valves (not shown) linked to the respective camshafts are reciprocated. The VVT 13 is formed so that the valve characteristics such as the opening / closing timing of the intake / exhaust valve and the lift amount can be adjusted. The VVT 13 is controlled by oil whose flow rate is adjusted by an OCV (Oil Control Valve) 13a.

  As shown in FIGS. 1 and 5 to 7, the cylinder head 4 is formed with a plurality of branch oil supply passages 41 and 42 branched from the main gallery 31, four head side drain oil passages 44, and the like. . The third branch oil supply passage 41 has an upstream end connected to the main gallery 31 and a downstream end connected to the plurality of cam journals 14. Thus, the lubricating oil supplied from the main gallery 31 via the third branch oil supply passage 41 is supplied to both camshafts by the cam journal 14. The oil supplied to the cam journal 14 is returned from each head-side drain oil passage 44 after the lubrication of both cam shafts is completed.

  As shown in FIG. 1, the fourth branch oil supply path 42 has an upstream end connected to the main gallery 31 and a downstream end connected to the OCV 13 a. As a result, the oil supplied from the main gallery 31 via the fourth branch oil supply passage 42 is adjusted in flow rate by the OCV 13a, and then operates the VVT 13. The oil supplied to the VVT 13 is returned from each head side drain oil passage 44 after the operation is finished.

As shown in FIGS. 6 and 7, each head side drain oil passage 44 is formed on the exhaust side wall portion of the cylinder head 4 corresponding to the exhaust port 4 a of the cylinder head 4.
The head side drain oil passage 44 is formed to extend downward from the lower position of the exhaust port 4a to the lower end. The upstream end of each head side drain oil passage 44 is communicated by a substantially straight head side common oil passage 45 extending in the cylinder row direction, and the downstream end of each head side drain oil passage 44 is connected to each block side. The drain oil passages 34 are respectively connected to the upstream end portions.

  As shown in FIGS. 1, 6, and 7, a bypass passage 15 capable of bypassing oil is formed from the second branch oil supply passage 33 to the head-side common oil passage 45. The bypass passage 15 includes an upstream oil passage 36, a downstream oil passage 46, four branch oil passages 47, four exhaust port side oil passages 48, and a switching valve 16 (valve means). .

The upstream oil passage 36 is branched from the middle portion of the second branch oil passage 33 and is formed to extend in the vertical direction from the cylinder block 3 side to the downstream oil passage 46. The downstream oil passage 46 is disposed at a position substantially parallel to the head-side common oil passage 45 across the exhaust ports 4a, and extends from the upper position of the front exhaust port 4a to the upper position of the rear exhaust port 4a. Is formed. A downstream end portion of the upstream oil passage 36 is connected to the front end portion of the downstream oil passage 46.
Between the downstream side oil passage 46 and the head side common oil passage 45, four annular exhaust port side oil passages 48 are formed so as to surround each exhaust port 4a. Each exhaust port side oil passage 48 has an upstream end connected to the downstream oil passage 46 via a branch oil passage 47 and a downstream end connected to the head side common oil passage 45.

  The switching valve 16 is installed in the middle of the upstream oil passage 36. The switching valve 16 opens when the engine E is in a warm-up state and guides oil toward the check valve 8a to the upstream oil passage 36. When the engine E is warmed-up, the switching valve 16 closes and closes the upstream oil passage. The oil guided to 36 is cut off. As a result, when the engine E is in a warm-up state, the oil guided from the second branch oil passage 33 passes through the upstream oil passage 36 and the downstream oil passage 46, and then passes through each branch oil passage 47 to each exhaust port side oil passage 48. Distributed to. The oil flowing through each exhaust port side oil passage 48 is heated by exchanging heat with the exhaust gas via the exhaust port wall of the cylinder head 4, and then the head side drain oil passage from the head side common oil passage 45. 44 and returned to each block-side drain oil passage 34.

Next, the operation and effect of the oil circulation device 1 of the engine E will be described.
The oil circulation device 1 directs heat-receiving oil to a position near the exhaust port 4a by installing a bypass passage 15 that is a dedicated oil warming pipe, so that there is no change in the exhaust system structure or the exhaust layout. And the exhaust gas can be heat exchanged. As a result, when the engine E is in a warm-up state, the oil temperature is appropriately raised early to reduce the oil viscosity regardless of the coolant temperature of the engine E, and the main journal 10, the pin journal 11, the cam journal 14, etc. The mechanical resistance of the lubrication target part can be reduced.

  Since the exhaust system structure and the exhaust layout are not changed, the manufacturing cost can be suppressed without increasing the flow resistance of the exhaust gas. Of the plurality of branch oil supply paths 32, 33, 41, 42, the oil can be directed from the second branch oil supply path 33 connected to the oil jet 8 to which the cooling oil is supplied to a position near the exhaust port 4a. Therefore, when the engine E is in a warm air state, the cooling oil supplied to the piston 7 can be used as a heat receiving medium for receiving heat from the exhaust gas, and the piston 7 is prevented from being overcooled by the cooling oil, thereby stabilizing the combustion property. Early warming of the engine E can be promoted, and as a result, the fuel efficiency of the engine E can be improved.

  A plurality of block-side drain oil passages 34 are connected to the plurality of head-side drain oil passages 44 and return the oil to the inner oil pan 2b, and each exhaust port-side oil passage 48 is formed in an annular shape so as to surround the exhaust port 4a. In addition, since the plurality of head side drain oil passages 44 and the plurality of block side drain oil passages 34 are provided on the exhaust side wall portion of the engine E, the bypass passage 15 that can receive heat from the exhaust gas can be formed long, and heat is received from the exhaust gas. The amount of heat that can be increased.

  An oil guiding portion 35 is provided for guiding the reflux oil heated through the exhaust port side oil passage 48 to the oil strainer 6a of the oil pump 6 as a temperature rising oil request portion where the heated oil is required. Therefore, the reflux oil heated by the oil guiding portion 35 can be collected at the intake port of the oil strainer 6a, and early warming of the engine E can be promoted.

  The oil guide portion 35 collects the plurality of introduction portions 35a for introducing oil from the downstream ends of the plurality of block side drain oil passages 34, and collects the introduced introduction portions 35a and supplies the introduced oil to the oil strainer of the oil pump 6. Since it has the derivation | leading-out part 35b derived | led-out to the position near the inlet of 6a, the reflux oil heated up by the oil guide part 35 can be collected to the position near the inlet of the oil strainer 6a, and the heated reflux oil The oil pump 6 can recirculate without lowering the temperature of the engine E, and the early warm-up of the engine E can be promoted.

  The oil guide 35 includes an inner oil pan 2b that surrounds the suction port of the oil strainer 6a and is housed inside the outer oil pan 2a, and the lead-out portion 35b guides the reflux oil to the inner oil pan 2b. The oil heated by the unit 35 can be reliably collected in the inner oil pan 2b, the limited oil can be recirculated by the oil pump 6, and the early warming of the engine E can be promoted.

  The cylinder block 3 includes an oil jet 8 that can inject oil to the piston 7, and the bypass passage 15 is formed to branch from a second branch oil supply passage 33 that supplies oil to the oil jet 8, and the switching valve 16 is opened. Since the flow rate of the oil supplied to the oil jet 8 is limited when the valve is operated, when the engine E is warmed up, the cooling performance of the piston 7 is maintained, and when the engine E is in the warmed state, Thus, the flow rate of the low-temperature oil injected can be reduced to prevent the piston 7 from being overcooled, and the combustion property can be stabilized at an early stage.

Next, a modification of the first embodiment will be described with reference to FIG. In addition, about the member similar to Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.
The difference from the first embodiment is that, in the first embodiment, four block-side drain oil passages 34 are formed corresponding to each cylinder, whereas in the oil circulation device 1A of this modification, the block-side drain oil is formed. The point is that two paths 34A are formed.

  The two block-side drain oil passages 34A are formed on the exhaust side wall portion of the cylinder block 3A so as to extend in the vertical direction from the upper end to the lower end of the cylinder block 3A. The front block side drain oil passage 34A is provided in a portion between the front end cylinder and the adjacent cylinder, and the rear block side drain oil passage 34A is provided in a portion between the rear end cylinder and the adjacent cylinder. It has been.

  The oil guide part 35A includes two introduction parts 35c and one lead-out part 35d. Each of the two introduction portions 35c has an upstream end connected to a downstream end of each block-side drain oil passage 34A. The lead-out part 35d is formed by collecting downstream portions of the two introduction parts 35c. The lead-out portion 35d extends from the gathering portion of the downstream portion of each introduction portion 35c so as to approach the oil strainer 6a. Two head-side drain oil passages (not shown) are formed from the head-side common oil passage 45, and are connected to upstream ends of the respective block-side drain oil passages 34A. According to this oil circulation device 1A, it is possible to achieve the same effects as in the first embodiment and to simplify the structure.

Next, another modification of the first embodiment will be described with reference to FIG. Note that members similar to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
The difference from the first embodiment is that, in the first embodiment, four block-side drain oil passages 34 are formed corresponding to each cylinder, whereas in the oil circulation device 1B of this modification, four blocks are provided. This is a point where the side drain oil passage 34B is gathered in the middle of the two block side drain oil passages 34C.

The four block side drain oil passages 34B are formed in the exhaust side wall portion of the cylinder block 3A so as to extend in the vertical direction from the upper end to the middle portion of the cylinder block 3B.
The block-side drain oil passage 34B of the front end cylinder and the block-side drain oil passage 34B of the cylinder adjacent thereto are gathered in the middle to form a block-side drain oil passage 34C. The block-side drain oil passage 34C is provided at an inter-cylinder portion between the front end cylinder and the adjacent cylinder, and is formed so as to extend in the vertical direction from the middle portion to the lower end of the cylinder block 3B. Similarly, the block-side drain oil passage 34B of the rear end cylinder and the block-side drain oil passage 34B of the cylinder adjacent thereto are gathered in the middle to form a block-side drain oil passage 34C. The block-side drain oil passage 34C is provided in an inter-cylinder part between the rear end cylinder and the adjacent cylinder, and is formed to extend in the vertical direction from the middle part to the lower end of the cylinder block 3B. According to this oil circulation device 1B, the same effects as those of the first embodiment can be obtained.

The oil circulation device 1C according to the reference technique will be described with reference to FIGS. Note that members similar to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
The difference from the first embodiment is that, in the first embodiment, the temperature rising oil requesting portion is the oil strainer 6a of the oil pump 6, whereas in the present reference technique , the temperature rising in which the heated oil is required. The oil demanding part is the crankshaft 9A.

  As shown in FIGS. 10 and 11, the four block-side drain oil passages 34 </ b> D are formed in the exhaust side wall portion of the cylinder block 3 </ b> C so as to extend in the vertical direction from the upper end to the lower end of the cylinder block 3 </ b> C. Each block-side drain oil passage 34D is disposed at a cylinder arrangement orthogonal position with respect to the cylinder bore 3a of each cylinder.

  A lower portion of the block side drain oil passage 34D of the front end cylinder is bent toward the adjacent cylinder side, and a lower end portion thereof is disposed on the cylinder side adjacent to the axis of the cylinder bore 3a. A lower portion of the block side drain oil passage 34D of the cylinder adjacent to the front end cylinder is bent toward the front end cylinder, and a lower end portion thereof is disposed on the front end cylinder side with respect to the axis of the cylinder bore 3a. Similarly, the lower part of the block side drain oil passage 34D of the rear end cylinder is bent to the adjacent cylinder side, and the lower end portion thereof is disposed on the cylinder side adjacent to the axis of the cylinder bore 3a. The lower part of the block side drain oil passage 34D of the cylinder adjacent to the rear end cylinder is bent toward the rear end cylinder, and its lower end is disposed on the rear end cylinder side with respect to the axis of the cylinder bore 3a.

  An oil guide pipe 37 is provided at the lower end of each block-side drain oil passage 34D. The oil guide pipe 37 is formed in a cylindrical shape and is mounted so as to be inclined from the lower end portion of each block-side drain oil passage 34D toward the intake side. As will be described later, the openings of the oil guide pipes 37 are arranged so that the recirculated oil can be dropped onto the rotation locus portions of the crank pin portions 9b.

  The crankshaft 9A includes four crankpin portions 9b, four oil reservoir portions 9c, four oil through holes 9d, and the like. Each oil reservoir 9c is formed at one end side position in the front-rear direction corresponding to the rotation locus portion of each crankpin portion 9b. The oil reservoir 9c is recessed and formed in the crankpin portion 9b. When the crankpin portion 9b in which the oil reservoir 9c is formed approaches the oil guide tube 37, the oil reservoir 9c opens the oil guide tube 37. Is formed at a substantially lower position in the vertical direction. Therefore, the oil recirculated from each block-side drain oil passage 34D is supplied to each oil reservoir 9c every time the crankshaft 9A makes one revolution.

  Each oil through-hole 9d is formed so that one end in the front-rear direction is connected to the oil reservoir 9c and penetrates each crank pin 9b from one end to the other end in the front-rear direction. The oil through hole 9d is formed such that when the crank pin portion 9b in which the oil through hole 9d is formed approaches the oil guide pipe 37, one end side in the front-rear direction is in an upper position compared to the other end side. Therefore, when the crank pin portion 9b approaches the oil guide pipe 37, the oil stored in the oil reservoir portion 9c flows from the one end side to the other end side by the weight of the oil through hole 9d.

  According to the oil circulation device 1C, in addition to the same effects as in the first embodiment, the oil guide pipe 37 that drops the reflux oil from the downstream ends of the plurality of block-side drain oil passages 34D to the rotation locus portion of the crankpin portion 9b. Therefore, the reflux oil heated by the oil guide pipe 37 can be concentrated and supplied to the rotation locus portion of the crankpin portion 9b of the crankshaft 9A, and the early temperature rise of the crankpin portion 9b can be promoted.

Next, a modification of the reference technique will be described with reference to FIG.
Difference from the reference technique are the reference technology, to the oil through hole 9d from the longitudinal direction end side of the crank pin portion 9b was formed so as to penetrate over the other end, the oil circulation of the modification In the apparatus 1D, an oil closing hole 9e whose other end is closed is provided.

Four oil blocking holes 9e are formed in each crankpin portion 9b of the crankshaft 9B.
Each oil blocking hole 9e is formed such that one end in the front-rear direction is connected to the oil reservoir 9c, and each crank pin 9b is extended from one end in the front-rear direction to the middle of the crank pin 9b. The oil blocking hole 9e is formed such that when the crank pin portion 9b in which the oil blocking hole 9e is formed approaches the oil guide pipe 37, one end side in the front-rear direction is in an upper position compared to the other end side. According to this modification, the same effects as those of the reference technique can be achieved.

Next, a modification in which the above embodiment is partially changed will be described.
1) In the above-described embodiment, an example of a horizontal 4-cylinder engine has been described. it can. It can also be applied to a vertical engine.

2] In the above embodiment, an example in which the bypass passage is branched from the second branch oil supply passage that supplies oil to the piston oil jet has been described. However, at least when the engine is warm, the supply of oil can be reduced. Any branch oil supply path connected to the appropriate oil supply target portion may be used, and any of the branch oil supply paths can be branched according to the demand condition of the oil. Further, the number of oil supply target portions is not limited to one, and may be bypass passages branched from a plurality of branch oil supply passages, and a plurality of bypass passages may be connected to the head side drain oil passage.

3) In the above embodiment, the example in which the bypass passage is provided with the annular exhaust port side oil passage surrounding the exhaust port has been described, but at least the oil flowing in the exhaust port side oil passage can exchange heat with the exhaust gas. It is also possible to use a part of the upstream side oil passage of the bypass passage also as the exhaust port side oil passage, and the upstream oil passage can be directly connected to the head side drain oil passage at a position near the exhaust port.
4) In addition, those skilled in the art can implement the present invention in various forms added with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

  The present invention provides an engine oil circulation device that increases the exhaust resistance and exhaust system layout by flowing oil supplied to an oil supply target portion to an exhaust port side oil passage through a bypass passage when the engine is warm. The oil temperature can be raised without causing any change, and the overcooling of the oil supply target portion can be suppressed and warming can be promoted.

1, 1A, 1B, 1C, Oil circulation device 1D
2a Outer oil pan 2b Inner oil pan 3, 3A, 3B, 3C Cylinder block 4 Cylinder head 4a Exhaust port 7 Piston 8 Oil jet 9, 9A, 9B Crankshaft 10 Main journal 11 Pin journal 13 VVT
14 cam journal 15 bypass passage 16 switching valve 32 first branch oil passage 33 second branch oil passage 34, 34A, 34B, block side drain oil passage 34C, 34D
35, 35A Oil guiding portions 35a, 35c Introducing portions 35b, 35d Deriving portions 37 Oil guiding pipe 41 Third branch oil passage 42 Fourth branch oil passage 44 Head side drain oil passage 48 Exhaust port side oil passage E Engine

Claims (3)

A plurality of oil supply target portions equipped in the cylinder block and the cylinder head, an oil pump for sucking oil stored in an oil pan and discharging it to the main oil passage, and the plurality of oil supply target portions branched from the main oil passage In an oil circulation device for a multi-cylinder engine, comprising a plurality of branch oil supply passages for supplying oil to the oil supply and a plurality of head side drain oil passages capable of returning oil from the plurality of oil supply target portions to an oil pan
A bypass passage branched from any one of the plurality of branch oil passages, a downstream oil passage formed over an upper position of the exhaust port of the multi-cylinder of the cylinder head ; and and multiple exhaust port side oil passage Ru annular to be formed and the oil to the plurality of head-side drain oil passage is directed to surround the exhaust port of the multi-cylinder, a plurality of exhaust ports top from the downstream oil passage A bypass passage including a plurality of branch oil passages that respectively distribute oil to the exhaust port side oil passage;
Valve means provided in the bypass passage and opened when the engine is in a warm-up state and closed when the warm-up is completed ,
A plurality of block-side drain oil passages connected to the plurality of head-side drain oil passages for returning oil to an oil pan;
An oil guiding part is provided for guiding the oil refluxed via the exhaust port side oil passage to the temperature rising oil requesting part where the heated oil is required,
An oil circulation device for an engine, wherein the oil guide portion includes an inner oil pan that surrounds an inlet of an oil pump and is housed in an oil pan, and leads the returned oil to the inner oil pan . The oil guide portion is configured to introduce a plurality of introduction portions that introduce oil from the downstream ends of the plurality of block-side drain oil passages, and to collect the introduced introduction portions and introduce the introduced oil to a position near the suction port of the oil pump. The engine oil circulation device according to claim 1, further comprising a deriving unit for deriving . The cylinder block has an oil jet that can inject oil into the piston.
The bypass passage is formed to branch from a branch oil supply passage that supplies oil to the oil jet, and an amount of oil supplied to the oil jet is limited when the valve means is opened. Item 3. The engine oil circulation device according to Item 1 or 2.