JP2012197690A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more properly ensure circulation of oil, even if an oil filter is temporarily clogged which contains multiple substances included in a lubricating device of an internal combustion engine.SOLUTION: This internal combustion engine 10 includes: the oil filter 32, which is arranged in an oil passage 34, for receiving multiple substances having functions of absorbing predetermined components; a bypass passage 40, which communicates with the oil passage 34, and which is extended to bypass the oil filter 32; and a flow controller 42 for controlling the flow of the oil in the bypass passage 40. The flow controller 42 is configured to allow the oil of the upstream side of the oil filter 32 to flow into the bypass passage 40, when the oil filter 32 is temporarily clogged as the viscosity of the oil in the oil filter 32 is more than a predetermined viscosity.

Description

  The present invention relates to an internal combustion engine that can be used in an automobile or the like.

  Patent Document 1 discloses a chemical filter used in a lubrication system of an internal combustion engine. According to the description of Patent Document 1, this chemical filter is used in a housing of an oil filter in an internal combustion engine lubrication system or used in a bypass portion of the oil filter and can have an ion exchange material. .

Special table 2008-540123

  The oil filter can contain an ion exchange material. However, since the oil generally has the characteristic that the viscosity of the oil increases as the temperature of the oil decreases, the oil tends to hardly pass through an oil filter including a plurality of substances such as ion exchange materials as the temperature of the oil decreases. . And since the viscosity of oil is high, when the oil filter is temporarily clogged, it is desired to ensure the oil circulation in the lubricating device of the internal combustion engine so that the oil flow does not stagnate.

  Therefore, the present invention has been made in view of such a point, and the purpose thereof is to more appropriately ensure oil circulation even when an oil filter including a plurality of substances is temporarily clogged. There is.

  An internal combustion engine according to an aspect of the present invention is provided in an oil passage, and includes an oil filter containing a plurality of substances having a function of adsorbing predetermined components, and bypasses the oil filter in communication with the oil passage. And a flow rate adjusting device for adjusting the flow rate of oil in the bypass passage, wherein the oil filter is in a temporarily clogged state because the oil viscosity in the oil filter is not less than a predetermined viscosity. And a flow rate adjusting device configured to allow the oil on the upstream side to flow into the bypass passage.

  The flow rate adjusting device may include a mechanism for opening the bypass passage when the pressure of oil on the upstream side of the oil filter exceeds a predetermined pressure.

  The bypass passage may be configured to be able to exchange heat with the oil filter.

  The bypass passage may be configured to pass through the oil filter.

  The bypass passage may be configured to contact the oil filter.

  A second flow rate adjusting device that adjusts the flow rate of the oil toward the oil filter according to the viscosity of the oil in the oil passage may be further provided.

1 is a conceptual diagram of an internal combustion engine according to an embodiment of the present invention. FIG. 2 is an enlarged schematic view of an oil filter of the internal combustion engine of FIG. 1 and its surroundings. It is a figure for demonstrating control of the control valve of the internal combustion engine of FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 conceptually shows an internal combustion engine (hereinafter, engine) 10 according to an embodiment of the present invention. Here, the internal combustion engine 10 is mounted on a vehicle. However, the engine 10 in the present embodiment is an in-line four-cylinder engine, but the engine to which the present invention is applied is not only the number of cylinders and the cylinder arrangement type, but is a spark ignition engine or a compression ignition type engine. It doesn't matter if it's an institution.

  The engine 10 includes a cylinder block 12 that is integrally provided with a crankcase, a cylinder head 14, a head cover 16 that covers the cylinder head 14 from above, and an oil pan 18. The air-fuel mixture of the air taken in through the throttle valve 22 of the intake passage 20 and the fuel injected from the fuel injection valve is combusted in the combustion chamber, and the exhaust gas is discharged through the exhaust passage 24.

  An oil return passage (oil dropping passage) 26 is formed (provided) in the cylinder block 12 and the cylinder head 14 so as to communicate the inside of the head cover 16 or the inside of the cylinder head 14 and the inside of the crankcase, that is, the oil pan 18. ing). The oil return passage 26 is, for example, a passage for returning (dropping) oil that has finished lubrication of the valve system from the cylinder head 14 into the oil pan 18, and at the same time, blow-by gas in the crankcase is passed into the head cover 16. It is a passage for making it move upward toward. The number of oil return passages 26 may be any number.

  Here, blow-by gas is gas that leaks into the crankcase from the gap between the piston ring of the piston and the cylinder bore of the cylinder block 12. This blow-by gas contains a large amount of hydrocarbons and moisture. For this reason, too much blow-by gas causes premature deterioration of engine oil and rust inside the engine. Further, since the blow-by gas contains hydrocarbons, it is not environmentally preferable to release it to the atmosphere as it is. Therefore, the engine 10 includes a blow-by gas recirculation device (not shown). After the blow-by gas is introduced into the head cover 16, it is forcibly returned to the intake system through a route described later using intake negative pressure and supplied to the combustion chamber.

  Although not shown, the blow-by gas recirculation device includes a PCV passage that connects the intake passage on the downstream side of the throttle valve 22 and the inside of the head cover 16. Here, PCV is an abbreviation for Positive Crankcase Ventilation. Further, the intake passage on the upstream side of the throttle valve 22 and the inside of the head cover 16 are communicated with each other by an atmospheric passage. A PCV valve that opens and closes the PCV passage is provided. The PCV valve opens and closes in accordance with the magnitude of the intake negative pressure and changes the flow rate. Here, the PCV valve is fixed to the head cover 16.

  By the way, such blow-by gas contains NOx, SOx and moisture. For example, the head cover 16 is difficult to transmit heat from the engine and its outer surface is exposed to the outside air and cooled by cooling air or the like, so that condensed water due to condensation or the like tends to be generated on the inner surface of the head cover 16. Therefore, particularly in the head cover 16, acidic substances such as nitric acid and sulfuric acid are likely to be formed by the reaction. These acidic substances can be mixed with lubricating oil, that is, engine oil, and can promote generation, adhesion, and accumulation of sludge inside the engine.

  Therefore, the lubricating device 30 of the engine 10 has an oil filter 32 in order to remove such acidic substances, that is, acidic components from the engine oil. In FIG. 1, only a part of the lubricating device 30 is exaggerated and schematically shown. The lubrication device 30 has an oil passage 34 including the oil return passage 26 and the oil pan 18 in the engine 10, and includes an oil filter 32 in the middle of the oil passage 34.

  However, in FIG. 1, a part of the lubrication device 30 including the oil filter 32 is drawn outside the engine body 10 ′ in order to exaggerately represent a part of the lubrication device 30 in the embodiment including the oil filter 32. . However, the installation position of the oil filter 32 and the like is not limited to the position shown in FIG. 1 and can be changed to various places, for example, at a part in contact with the outside of each part of the engine body 10 ′ or on the inside. Can be defined.

  The lubricating device 30 includes a strainer 36 and an oil pump 38, and the oil in the oil pan 18 is pumped (sucked) by the oil pump 38 through the strainer 36. The oil pumped up in this way passes through a main oil passage 34a (including a plurality of oil passages corresponding to each supply site) formed in the engine 10 via an oil filter (not shown) (not shown). 10, for example, a camshaft journal, a crank journal, a connecting rod, and a piston. Then, the lubricating oil, that is, the oil thus supplied to each part finally returns to the oil pan 18 by its own weight. A space in which oil flows in such a manner as to circulate in the engine 10 is referred to herein as an “oil passage”.

  Here, the oil passage 34 includes the main oil passage 34a and a sub oil passage 34b connected to the main oil passage 34a. The oil filter 32 is positioned in the sub oil passage 34b. However, the oil filter 32 may be provided in the main oil passage 34 a, for example, in the oil return passage 26. The oil that has flowed into the auxiliary oil passage 34b can finally flow into the oil pan 18 due to its own weight.

  The oil filter 32 in the lubricating device 30 is partitioned by the filter parts 32a and 32b, the outer shell member 32c, and the outer shell member 32c and the filter parts 32a and 32b so as to be sandwiched between the filter parts 32a and 32b. It has a formed accommodating portion (accommodating chamber) 32d (see FIG. 2). Each of the filter portions 32a and 32b is a porous member, and specifically has a plurality of pores through which oil substantially extending in the flow channel direction (directions of arrows a1 and a2 in FIG. 2) can flow. The filter portions 32a and 32b are provided so as to capture solid matter such as solid particles in the oil. The filter portions 32a and 32b maintain the shape and size of the storage portion 32d, and are provided to protect and hold a plurality of reactants (or filter bodies), that is, substances, provided in the storage portion 32d. Yes.

The plurality of reactants accommodated in the accommodating portion 32d are mainly composed of hydrotalcite that functions as an ion exchanger (ion exchange material). Hydrotalcite has a function of adsorbing predetermined ions (ionic components). In other words, the reactant of the housing portion 32d has a function of adsorbing such predetermined ions in order to remove the predetermined ions from the engine oil. Specifically, nitrate ions (NO ₃ ⁻ ) that can be generated by NOx and water in blow-by gas, and sulfate ions (SO ₄ ²⁻ ) that can be generated by SOx and water in blow-by gas should be removed from the oil. Hydrotalcite is provided. Various hydrotalcites can be used as the hydrotalcite, for example, “Mg ₆ Al ₂ (OH) (CO ₃ ) ₁₆ ” manufactured by Wako Pure Chemical Industries, Ltd. can be used.

  Therefore, when the oil passes through the oil filter 32 provided in the sub oil passage 34b of the oil passage 34 of the lubrication device 30, the above-mentioned in the oil is caused by the action of the plurality of reactants in the housing portion 32d of the oil filter 32. Such components can be removed from the oil.

  By the way, such a hydrotalcite is accommodated in the accommodating part 32d of the oil filter 32 in a very fine state here, for example, in a fine particle state. In other words, many (plural) fine hydrotalcites are accommodated in the accommodating portion 32d of the oil filter 32.

  On the other hand, the engine oil flowing through the oil passage 34 of the lubricating device 30 generally has a characteristic that its viscosity increases as its temperature decreases. In general, when the viscosity of the oil is low, the oil can flow between the reactants of the oil filter 32. However, when the viscosity of the oil is equal to or higher than the predetermined viscosity, the oil is difficult to flow between the plurality of reactants of the oil filter 32, and can temporarily stay between them, for example. In such a case, the plurality of reactants are mixed with the oil to form a mud, and the oil filter 32 is temporarily clogged. Even in such a case, it is desirable to ensure the oil circulation in the sub oil passage 34b. Therefore, a bypass passage 40 extending so as to bypass the oil filter 32 is provided.

  The bypass passage 40 communicates with the sub oil passage 34 b in the oil passage 34. The bypass passage 40 is formed so as to diverge from the upstream portion of the oil filter 32 and to join the downstream portion thereof. The upstream end 40a of the bypass passage 40 is positioned above the downstream end 40b in the vertical direction. Therefore, when it is difficult to distribute oil in the oil filter 32, the oil accumulated on the upstream side in the vertical direction above the oil filter 32 is guided to the downstream side of the oil filter 32 through the bypass passage 40 by its own weight. Can do.

  However, it is usually desired to remove the above-described components from the oil by passing the oil through the oil filter 32. Therefore, when the oil becomes difficult to pass through the oil filter 32 as described above, that is, when the oil viscosity in the oil filter 32 is equal to or higher than a predetermined viscosity and the oil filter 32 is temporarily clogged, A flow rate adjusting device 42 is provided to allow oil to flow through 40.

  The flow rate adjusting device 42 is a device that adjusts the flow rate of oil in the bypass passage 40 and is configured to allow oil to flow into the bypass passage 40 in accordance with the oil passage resistance in the oil filter 32. Specifically, as schematically shown in FIG. 2, the flow rate adjusting device 42 is capable of moving forward and backward with respect to the valve seat 42 a and can be seated thereon, and the valve body 42 b is attached to the valve seat 42 a. And a spring 42c as an urging member for urging the urging member. The biasing member is not limited to the spring 42c, and may be composed of another elastic body. The spring 42c is designed and selected to allow oil to flow through the bypass passage 40 when the oil passage resistance in the oil filter 32 is higher than a predetermined level. In other words, when the oil filter 32 is in the temporarily clogged state, oil can accumulate on the upstream side of the oil filter 32, but in this case, the spring 32 so that the pressure of the accumulated oil exceeds the urging force of the spring 32. Is structured. As described above, the flow rate adjusting device 42 includes a mechanism that opens the bypass passage 40 when the pressure of the oil upstream of the oil filter 32 exceeds a predetermined pressure. Therefore, in such a case, the oil accumulated on the upstream side of the oil filter 32 can flow into the bypass passage 40 and can flow into the oil pan 18 by bypassing the oil filter 32 (see arrows a3 and a4 in FIG. 2). ). Therefore, it is possible to prevent the oil flow from stagnation in the lubricating device 30 of the engine 10.

  The bypass passage 40 is configured to be capable of exchanging heat with the oil filter 32, and in particular, capable of exchanging heat with the housing portion 32d. Specifically, as shown in FIG. 2, the bypass passage 40 is configured to pass through the accommodating portion 32 d of the oil filter 32 so that heat can be exchanged between them. Therefore, heat can be supplied from the oil flowing through the bypass passage 40 to the housing portion 32d of the oil filter 32 to warm the housing portion 32d. Note that the bypass passage 40 may be configured to be in contact with the oil filter 32, for example, to be in contact with the periphery of the accommodating portion 32d. In this case, heat can be supplied to the oil filter 32 from the periphery. Further, the bypass passage 40 can be configured to be able to exchange heat with other portions of the oil filter 32.

  For example, when a plurality of reactants are mixed with oil having a high viscosity in the accommodation portion 32d of the oil filter 32 and become muddy, the oil may flow into the bypass passage 40 via the flow rate adjusting device 42 as described above. it can. For example, when a predetermined time has elapsed since the engine 10 started operating, the temperature of the oil exceeds the predetermined temperature. Accordingly, since the oil flowing through the bypass passage 40 at such time exceeds a predetermined temperature and is warm or hot, the accommodation portion 32d is heated by the heat of the oil being transmitted. As a result, even when the oil filter 32 is in a temporarily clogged state as described above, the temperature of the oil in the oil filter 32 can be quickly raised to increase its fluidity and weaken the aggregation of a plurality of reactants. it can. Therefore, the temporary clogging of the oil filter 32 can be quickly eliminated.

  And in the lubrication apparatus 30, since the temperature of engine oil is low, when the viscosity is high, the 2nd flow volume adjustment apparatus 44 is provided so that oil may flow toward the oil filter 32. The second flow rate adjusting device 44 includes a control valve 46 that is a flow rate adjusting valve and a part of an electronic control unit (ECU) (not shown) that functions as a control means for controlling the opening / closing operation thereof. .

  Here, the control valve 46 is provided at the upstream end of the sub oil passage 34b so as to adjust the flow rate of oil to the oil filter 32 of the sub oil passage 34b (see FIG. 1). Specifically, the control valve 46 is selectively controlled between a fully open state and a fully closed state. Here, the control valve 46 opens and closes when an actuator is operated based on an operation signal from the ECU.

  The engine 10 includes the ECU. The ECU is composed of a microcomputer including a CPU, ROM, RAM, A / D converter, input interface, output interface, and the like. The input interface includes an engine rotation speed sensor for detecting the engine rotation speed, an engine load sensor for detecting the engine load, a viscosity sensor 48 as a viscosity detection means for detecting the viscosity of the engine oil, and the like. Sensors are electrically connected. Based on the output signals (detection signals) from these various sensors, the ECU is electrically connected to the fuel injection valve and the throttle valve from the output interface so that the engine 10 can be smoothly operated or operated in accordance with a preset program. An operation signal (drive signal) is output to the actuator for 22 and the actuator for the control valve 46.

  A part of such an ECU functions as a control unit for the control valve 46 of the second flow rate adjusting device 44. Further, the viscosity sensor 48 as a viscosity detecting means and a part of the ECU substantially constitute a viscosity detecting device for detecting the viscosity of the engine oil. Although the viscosity sensor 48 is provided in the oil pan 18, it can be provided in another part of the oil passage 34.

  Next, the operation control of the control valve 46 will be described with reference to FIG. Note that the flow of FIG. 3 is repeated after the engine 10 is started.

  First, it is determined whether or not the viscosity of the engine oil is equal to or higher than a predetermined viscosity (step S301). The viscosity of the oil is detected based on an output signal from the viscosity sensor 48. The predetermined viscosity is determined based on experiments in advance as a viscosity that may adversely affect the flow of oil in the oil filter 32 when the oil of that viscosity flows into the oil filter 32. More specifically, here, the predetermined viscosity is determined as to whether or not the oil filter 32 becomes temporarily clogged when the oil is mixed with a plurality of reactants of the oil filter 32 as described above. It is determined based on whether or not.

  For example, at the time of cold start or the like, the oil temperature is equal to or lower than a predetermined temperature, so the viscosity is equal to or higher than the predetermined viscosity. Therefore, in such a case, since the oil viscosity is equal to or higher than the predetermined viscosity (affirmative determination in step S301), the control valve 46 is controlled by the ECU so as to be closed (step S303). Here, the control valve 46 is normally closed.

  On the other hand, for example, when the temperature of the oil exceeds a predetermined temperature and the viscosity falls below the predetermined viscosity (No in step S301), the control valve 46 is controlled by the ECU to open (step S305). Accordingly, the oil flows toward the oil filter 32.

  Thereby, for example, when the passage resistance of the oil in the housing portion 32d of the oil filter 32 does not exceed a predetermined level, the oil flows into the oil filter 32 and the predetermined component can be removed from the oil. On the other hand, when the oil passage resistance in the accommodating portion 32d of the oil filter 32 is higher than a predetermined level, that is, when the oil filter 32 is temporarily clogged, a part of the oil may pass through the oil filter 32. The oil can flow into the bypass passage 40 as described above. Thereby, the accommodating part 32d of the oil filter 32 can be heated by the oil of the bypass passage 40 as described above. Therefore, the fluidity of the reactant and oil in the housing portion 32d of the oil filter 32 is increased or the integrity of the reactants is relaxed, and the passage resistance of the oil filter 32 can be lowered.

  In the above embodiment, the viscosity sensor 48 is provided to detect the viscosity of the engine oil. However, a temperature sensor (temperature detection means) for detecting the temperature of the engine oil may be provided in addition to or instead of the viscosity sensor 48. it can. In this case, the temperature sensor and a part of the ECU substantially constitute a temperature detection device for detecting the temperature of the engine oil or a viscosity detection device for detecting the viscosity of the engine oil. Based on this, the opening / closing operation of the control valve 46 can be controlled. This is because the viscosity of the engine oil has a correlation with its temperature. The ECU may control the opening / closing operation of the control valve 46 based on both the temperature and viscosity of the engine oil detected separately.

  As mentioned above, although this invention was demonstrated based on the said embodiment, the flow volume adjusting device 42 is not limited to the above structures, for example. When the viscosity of the oil in the oil filter 32 is so high that the oil filter 32 is temporarily clogged, the oil can collect on the upstream side of the oil filter 32. Therefore, the flow control device 42 can be configured to detect the presence of the oil accumulated in such a manner and open the bypass passage 40. In this case, the flow rate adjusting device 42 includes a control valve for adjusting the flow rate of oil in the bypass passage, a sensor as oil amount detecting means for detecting the amount of oil accumulated on the upstream side of the oil filter 32, Control means for controlling the opening and closing operation of the control valve based on the output from the sensor. The function of the control means can be carried by a part of the ECU. A sensor as an oil amount detecting means for detecting the amount of oil accumulated on the upstream side of the oil filter 32 can be provided, for example, in an oil reservoir of an oil passage on the upstream side of the oil filter 32.

  The reactant used in the oil filter is not limited to the hydrotalcite as described above. The reactant may be a substance having a function of adsorbing and removing a predetermined component from the oil, and may be, for example, an ion exchange resin. Various anionic ion exchange resins and cationic ion exchange resins can be used as the reactant. Examples of ion exchange resins include Diaion (registered trademark) series ion exchange resins manufactured by Mitsubishi Chemical Corporation and Amberlite (registered trademark) series ion exchange resins manufactured by Rohm and Haas.

Ionic components that are desired to be removed from the oil by using reactants such as anionic ion exchange resins include not only nitrate ions (NO ³⁻ ) and sulfate ions (SO ₄ ²⁻ ), but also blowby gas, for example. There are acetate ions (CH ₃ COO ⁻ ) that can be generated from the above, as well as formate ions (HCOO ⁻ ), chloride ions (Cl ⁻ ), and chromate ions (CrO ₄ ²⁻ ) that can be generated from blow-by gas. A reactant having a function of adsorbing at least one ionic component selected from the group containing these or a group consisting of these may be used.

  When an alkaline substance such as calcium carbonate is provided on the oil passage, for example, the inner surface of the head cover 16 so as to suppress sludge generation, a reactant having a function of adsorbing Ca ions may be used. In addition, when calcium sulfonate is added as an additive in the oil, Ca ions can be generated from this calcium sulfonate. In such a case, when a reactant having a function of adsorbing Ca ions is used. Good.

In addition, not only such Ca ions (Ca ²⁺ ) but also, for example, Al ³⁺ , Fe ²⁺ , Fe ³⁺ are ions desired to be removed from the oil by using a reactant such as a cationic ion exchange resin. , Cr ³⁺ , Pb ²⁺ , Ni ²⁺ , Cu ²⁺ , Mg ²⁺ , Ti ⁺ . These can come from additives to the oil, such as ZnDTP, or from wear and / or elution of engine components. In particular, it is desired that Cu ions, Al ions, Fe ions, and the like generated in engine oil due to wear of the sliding portion of the engine be removed. A reactant having a function of adsorbing at least one ionic component selected from the group containing these or a group consisting of these may be used.

  Further, the substance such as the reactant may be other than hydrotalcite or ion exchange resin. It is possible to use reactants such as inorganic ion exchangers, chelate resins, and synthetic adsorbents. As the reactant, various substances having a function of adsorbing a predetermined component, and various substances having a function of adsorbing a predetermined component and a function of releasing another predetermined component can be used.

  In addition, the components to be adsorbed and removed by the reactants are acids such as nitrate ions and sulfate ions, components generated from additives, components generated by wear and / or elution of engine components. It may be an unnecessary component or an impurity in the oil. The component to be adsorbed is not limited to the above ionic component, and may include components other than the ionic component. In addition, the component to be released from the reactant to the oil may be a component that is harmless to engine oil or a useful component that functions as an additive to the oil. Similarly, the component to be released is not limited to the above ions, and may include components other than ions.

  Since such reactants can be used to remove unwanted components or impurities in the oil, various materials and / or agents that can supply such unwanted components or impurities in the oil, It can also be added to oil as an antioxidant, a metallic detergent, a friction modifier, an ashless dispersant, and a pH adjuster.

  In addition, the substance accommodated in an oil filter is not limited to the said reactant. Various substances having a function of adsorbing a predetermined component can be accommodated in the oil filter. And especially this invention is effective when the several substance accommodated in an oil filter is a fine substance, respectively.

  Further, in the oil filter, a wire mesh case, a bag-like case formed using a wire mesh, a resin, or the like, a mesh type cylindrical case (having a storage area between the inner cylinder and the outer cylinder), and the like are used. A housing can be formed, and a plurality of substances can be placed therein.

  As described above, the present invention has been described based on the above embodiment and its modifications. However, the present invention is not limited to these embodiments and the like, and other embodiments are allowed. The present invention includes all modifications, applications, and equivalents included in the spirit of the present invention defined by the claims.

10 Engine 12 Cylinder block 14 Cylinder head 16 Head cover 18 Oil pan 20 Intake passage 22 Throttle valve 24 Exhaust passage 26 Oil return passage 30 Lubrication device 32 Oil filter 34 Oil passage 38 Oil pump 40 Bypass passage 42 Flow rate adjustment device 44 Second flow rate adjustment Device 48 Viscosity sensor

Claims (6)

An oil filter provided in the oil passage and containing a plurality of substances having a function of adsorbing a predetermined component;
A bypass passage communicating with the oil passage and extending to bypass the oil filter;
A flow control device for adjusting the flow rate of oil in the bypass passage, wherein the oil on the upstream side of the oil filter is in a temporarily clogged state because the oil viscosity in the oil filter is not less than a predetermined viscosity. An internal combustion engine comprising: a flow control device configured to allow flow to the bypass passage.   2. The internal combustion engine according to claim 1, wherein the flow rate adjusting device includes a mechanism that opens the bypass passage when the pressure of oil on the upstream side of the oil filter exceeds a predetermined pressure.   The internal combustion engine according to claim 1, wherein the bypass passage is configured to be able to exchange heat with the oil filter.   The internal combustion engine according to claim 3, wherein the bypass passage is configured to pass through the oil filter.   The internal combustion engine according to claim 3, wherein the bypass passage is configured to contact the oil filter.   The internal combustion engine according to any one of claims 1 to 5, further comprising a second flow rate adjusting device that adjusts a flow rate of the oil toward the oil filter in accordance with a viscosity of the oil in the oil passage.

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