JP4300926B2 - Thermal storage oil supply system for internal combustion engine - Google Patents

Description

  The present invention relates to a system for storing oil in an internal combustion engine in a heat storage container and supplying the oil.

  The lubricating oil (oil) of the internal combustion engine has a high viscosity when the temperature is low, and therefore reduces the efficiency of the internal combustion engine. Moreover, if the viscosity of the oil is high when the engine is started, the startability is deteriorated.

With respect to such problems, a technique for storing oil in a heat storage tank during operation of the internal combustion engine and supplying the oil to a piston when the engine is started (see, for example, Patent Document 1), and the oil stored in the heat storage tank for each lubrication site There is known a technique (for example, refer to Patent Document 2) that supplies the image data.
Japanese Patent Laid-Open No. 2002-242637 JP 2002-250212 A

  By the way, since the oil stored in the heat storage tank is limited, it is desired to supply this oil efficiently.

  The present invention has been made in view of the above-described problems, and in a heat storage oil supply system for an internal combustion engine, more effectively utilize oil stored in a heat storage container based on the temperature of the internal combustion engine. It aims at providing the technology that can do.

In order to achieve the above object, a heat storage oil supply system for an internal combustion engine according to the present invention employs the following means. That is,
A heat storage oil supply system for an internal combustion engine capable of supplying oil stored in a heat storage container to a plurality of lubrication parts at the time of starting the engine, depending on the engine temperature at the time of engine start, from the heat storage container to the plurality of lubrication parts A means for changing the oil supply ratio is provided.

  The greatest feature of the present invention is that oil having a high temperature (hereinafter referred to as heat storage oil) stored in a heat storage container is supplied to an optimum lubricating portion according to the engine temperature, thereby improving startability and fuel consumption. It is to plan.

  Here, the lubrication part of the internal combustion engine is lubricated in various manners. And the effect at the time of supplying thermal storage oil changes with the aspects of the lubrication, and the temperature of the internal combustion engine at that time. Then, when the heat storage oil is supplied, the limited heat storage oil is wasted in the lubricating part where the effect is not exhibited or the effect is small. In that respect, the heat storage oil is not supplied to such a lubrication site, and if the supply amount of the heat storage oil to the lubrication site where the effect is greatly increased is increased, the effect of the heat storage oil supply can be further increased. Thereby, it becomes possible to reduce the frictional force as the whole engine. Therefore, it is possible to effectively use limited oil by supplying more oil to the lubrication site where the effect of supplying heat storage oil is large. It should be noted that “at the time of engine start” may include before engine start, immediately after engine start, and even during warm-up.

  In the present invention, the lubrication site has a frictional force at the lubrication site that varies according to the engine temperature, and the frictional force varies from lubrication site to lubrication unit. The means for changing the supply rate is stored in a heat storage container. If the frictional force of the engine as a whole is reduced by supplying only the lubrication part selected from the plurality of lubrication parts, rather than supplying the oil to all lubrication parts when starting the engine, it is selected. Oil from the heat storage container can be supplied only to the lubrication site.

  Here, the frictional force at the lubrication site increases as the temperature of the oil decreases, and the magnitude varies depending on the mode of lubrication. And depending on the engine temperature, rather than supplying heat storage oil to all lubrication parts, supplying heat storage oil concentrates on the lubrication part where the reduction rate of frictional force is large by supplying heat storage oil. The frictional force can be reduced.

  In the present invention, the plurality of lubrication sites include at least a site where boundary lubrication is performed, and the means for changing the supply ratio is such that oil is supplied to all lubrication sites when the engine temperature is lower than a specified temperature. On the other hand, when the engine temperature is equal to or higher than a specified temperature, oil can be supplied to a portion other than the portion where boundary lubrication is performed.

  Here, the frictional force at the lubrication site increases as the temperature of the oil decreases, and the lubrication site where fluid lubrication is performed is larger than the lubrication site where boundary lubrication is performed. When the engine temperature is lower than the specified temperature, supplying the heat storage oil to all the lubrication sites can reduce the frictional force of all the lubrication sites. However, when the engine temperature is equal to or higher than the specified temperature, the frictional force decreases little even if the oil temperature is increased at the lubrication site where boundary lubrication is performed. Therefore, even if heat storage oil is supplied, the effect is small. Even in such a case, the frictional force is greatly reduced by supplying the heat storage oil at the lubrication site where the fluid lubrication is performed. Moreover, if heat storage oil is not supplied to the site | part where boundary lubrication is performed, the part can be supplied to another site | part. Accordingly, a large amount of heat storage oil can be supplied in addition to the portion where boundary lubrication is performed, and as a result, the frictional force of the entire engine can be reduced.

  Here, the “specified temperature” is a temperature at which the effect of reducing the frictional force is sufficiently obtained when the heat storage oil is supplied to the lubricated part where boundary lubrication is performed. Varies depending on the type. This “specified temperature” can be obtained in advance by experiments or the like.

  In the heat storage oil supply system for an internal combustion engine according to the present invention, the supply ratio of the heat storage oil to the plurality of lubrication sites is changed according to the engine temperature, and more heat storage oil is added to the lubrication sites where the effect of reducing the frictional force is large. Can be supplied. Thereby, limited heat storage oil can be used efficiently. Further, it is possible to effectively reduce the friction force at the time of starting the engine, and it is possible to improve the startability and fuel consumption of the internal combustion engine.

  Hereinafter, specific embodiments of a heat storage oil supply system for an internal combustion engine according to the present invention will be described with reference to the drawings. Here, the case where the heat storage oil supply system for an internal combustion engine according to the present invention is applied to a vehicle drive engine will be described as an example.

  Hereinafter, specific embodiments of a heat storage oil supply system for an internal combustion engine according to the present invention will be described with reference to the drawings. Here, the case where the heat storage oil supply system for an internal combustion engine according to the present invention is applied to a vehicle drive engine will be described as an example.

  FIG. 1 is a diagram illustrating a schematic configuration of an engine according to the present embodiment.

  The engine 1 includes a cylinder head 1a, a cylinder block 1b connected to the lower part of the cylinder head 1a, and an oil pan 1c connected to the lower part of the cylinder block 1b.

  The cylinder head 1 a includes an intake camshaft (hereinafter referred to as an IN camshaft) 2 and an exhaust camshaft (hereinafter referred to as an EX camshaft) 3. The IN camshaft 2 drives the intake valve, and the EX camshaft 3 drives the exhaust valve by pressing. Boundary lubrication is mainly performed at the place where each valve is pressed.

  The cylinder block 1b injects oil toward the piston 4 that reciprocates in the cylinder, the crankshaft 5 that converts the reciprocating motion of the piston 4 into rotational motion, the oil pump 6a, the oil filter 7, and the periphery of the piston 4. An oil jet 8 is provided. The oil pump 6 a discharges an amount of oil corresponding to the rotation speed of the crankshaft 5. Here, the crankshaft 5 is mainly subjected to fluid lubrication. Further, in the piston 4, oil is supplied between the piston ring and the cylinder wall, and mixed lubrication between fluid lubrication and boundary lubrication is performed.

  An oil passage 9 is formed in the engine 1. The oil passage 9 has a first oil passage 9 a that has one end opened in the oil stored in the oil pan and the other end connected to the inlet side of the oil filter 7, and one end connected to the outlet side of the oil filter 7. The second oil passage 9b, the other end of which is connected to the lubrication portion of the crankshaft, the third oil passage branched from the middle of the second oil passage 9b and connected to the lubrication portions of the IN camshaft 2 and the EX camshaft 3. 9c is provided. The oil pump 6a is provided in the middle of the first oil passage 9a, and the oil pump 6a is driven during operation of the engine 1 so that oil flows through the oil passage 9.

  A heat storage container 10 is connected to the oil passage 9. Oil having a high temperature is introduced into the heat storage container 10 during operation of the engine 1.

  One end of the first heat storage oil passage 9d is connected to the heat storage container 10, and the other end of the first heat storage oil passage 9d is connected to the four-way valve 11a. The four-way valve 11a includes a second heat storage oil passage 9e connected in the middle of the third oil passage 9c, a third heat storage oil passage 9f connected to the oil jet, and a third oil passage in the middle of the second oil passage 9b. A fourth heat storage oil passage 9g connected to the crankshaft 5 side with respect to the passage 9c is connected. Here, a three-way valve 11b is provided at a connection portion between the third oil passage 9c and the second heat storage oil passage 9e, and a three-way valve is provided at a connection portion between the second oil passage 9b and the fourth heat storage oil passage 9g. 11c is provided. The first heat storage oil passage 9d is provided with an electric pump 6b driven by electric power. Heat storage oil is circulated by the electric pump 6b.

  The four-way valve 11a selectively switches between communicating all the passages connected to the four-way valve 11a or communicating only between the first heat storage oil passage 9d and the fourth heat storage oil passage 9g.

  The three-way valve 11b selects either the oil filter 7 side of the third oil passage 9c or the second heat storage oil passage 9e, and the IN camshaft 2 and the EX camshaft 3 of the third oil passage 9c. Connect to the side.

Furthermore, the three-way valve 11c selects either the oil filter 7 side of the second oil passage 9b or the fourth heat storage oil passage 9g and connects it to the crankshaft 5 side of the second oil passage 9b.

  An oil temperature sensor 12 that outputs a signal corresponding to the temperature of the oil stored in the oil pan is attached to the oil pan 1c. In the present embodiment, the oil temperature obtained from the oil temperature sensor 12 is used as the engine temperature.

  By the way, when the engine 1 is started when the temperature of the engine 1 is high, it is not necessary to supply heat storage oil. In such a case, the three-way valve 11b selects the oil filter 7 side of the third oil passage 9c and connects it to the IN camshaft 2 and EX camshaft 3 side of the third oil passage 9c. The three-way valve 11c selects the oil filter 7 side of the second oil passage 9b and connects it to the crankshaft 5 side of the second oil passage 9b.

  By doing in this way, the oil pumped up from the oil pan 1c by the oil pump 6a is supplied to the crankshaft 5 through the first oil passage 9a and the second oil passage 9b. Further, it branches from the second oil passage 9b and is supplied to the IN camshaft 2 and the EX camshaft 3 through the third oil passage 9c. At this time, no electric power is supplied to the electric pump 6b, and no heat storage oil is supplied from the heat storage container 10.

  The oil that has been lubricated at each lubrication site falls through a plurality of oil dropping passages provided in the engine and returns to the oil pan 1c.

  The engine 1 configured as described above is provided with an electronic control unit (ECU) 13 for controlling the engine 1. The ECU 9 is a unit that controls the engine 1 in accordance with the operating conditions of the engine 1 and the driver's request.

  An output signal from the oil temperature sensor 12 is input to the ECU 13. On the other hand, the electric pump 6b, the four-way valve 11a, the three-way valve 11b, the three-way valve 11c, and the like are connected to the ECU 13 via electric wiring, and these can be controlled. The ECU 13 stores various application programs and various control maps.

  By the way, the amount of oil that can be stored in the heat storage container 10 is limited. In order to increase the storage amount, the heat storage container 10 is increased in size. Therefore, when mounting on a vehicle is taken into consideration, the oil storage amount cannot be increased too much. Therefore, it is desirable to use limited heat storage oil efficiently.

  Here, FIG. 2 is a diagram showing the relationship between the oil temperature and the frictional force at the lubrication site. “Crankshaft” indicates the relationship between the crankshaft 5 and the bearing, and fluid lubrication is performed here. The “piston ring” indicates the relationship between the piston ring provided in the piston 4 and the inner wall surface of the cylinder, and here, mixed lubrication is mainly performed. Furthermore, the “valve system” indicates the relationship between the IN camshaft 2 and EX camshaft 3 and members that slide on them, and here, boundary lubrication is mainly performed.

FIG. 2 (A) shows the relationship between the oil temperature and the frictional force at each lubrication site when the engine is started when the oil stored in the oil pan 1c is lower than the specified temperature. ing. The lower the oil temperature, the greater the rate of increase of the friction force. Further, the crankshaft in which fluid lubrication is mainly performed has a larger frictional force than the piston ring or valve system in which boundary lubrication is performed. Also, since the oil film formed on the piston ring is thicker than the valve system and lubrication is performed in a state closer to fluid lubrication, the frictional force at the piston ring is the value between the valve system and the crankshaft. It has become. In addition, the reduction rate of the frictional force when the oil temperature rises is the largest in the crankshaft, and decreases in the order of the piston ring and the valve train. For this reason, when the heat storage oil is supplied to the crankshaft that is most effective when the heat storage oil is supplied, the frictional force of the engine as a whole may be reduced.

  Here, FIG. 2A shows a comparison between the case where heat storage oil is supplied only to the crankshaft 5 and the case where heat storage oil is supplied to the crankshaft 5, piston ring, and valve train. If the heat storage oil is supplied only to the crankshaft 5, it is not necessary to supply the heat storage oil to other lubrication parts, so that a large amount of heat storage oil can be supplied to the crankshaft 5. As a result, the temperature of the oil at the crankshaft 5 rises to (b).

  On the other hand, if heat storage oil is supplied to the piston ring and the valve system in addition to the crankshaft, the amount of heat storage oil supplied to each lubrication site is reduced, but the frictional force can be reduced at all lubrication sites. it can. As a result, the oil temperature at each lubrication site rises to (a). And the sum of the reduction amount of the frictional force in each lubrication site | part at this time is larger than the case where thermal storage oil is supplied only to a crankshaft. Therefore, in such a case, the frictional force of the engine as a whole can be reduced by supplying heat storage oil to all of the crankshaft, piston ring, and valve train.

  On the other hand, FIG. 2B shows the relationship between the oil temperature and the frictional force when the engine is started when the oil stored in the oil pan 1c is equal to or higher than a specified temperature. When the temperature of the oil is higher than the specified temperature, even if the temperature of the oil rises, the frictional force is hardly reduced in the piston ring or the valve train.

  2B shows a comparison between the case where heat storage oil is supplied only to the crankshaft 5 and the case where heat storage oil is supplied to the crankshaft 5, piston ring, and valve train. If the heat storage oil is supplied only to the crankshaft 5, it is not necessary to supply the heat storage oil to other lubrication parts, so that a large amount of heat storage oil can be supplied to the crankshaft 5. As a result, the temperature of the oil at the crankshaft 5 rises to (b).

  On the other hand, if heat storage oil is supplied to the piston ring and the valve system in addition to the crankshaft, the amount of heat storage oil supplied to each lubrication site is reduced, but the frictional force can be reduced at all lubrication sites. it can. As a result, the oil temperature at each lubrication site rises to (a). However, the sum of the reduction amount of the frictional force at each lubrication part at this time is smaller than the case where the heat storage oil is supplied only to the crankshaft. Therefore, in such a case, supplying the heat storage oil only to the crankshaft can reduce the frictional force of the engine as a whole rather than supplying the heat storage oil to all the lubrication sites.

  In this respect, in this embodiment, when the oil temperature is lower than the specified temperature, the heat storage oil is supplied to the crankshaft, the piston ring, and the valve operating system, while the oil temperature is higher than the specified temperature. In this case, heat storage oil is supplied only to the crankshaft. In this embodiment, when the temperature of the oil is lower than the specified temperature, the heat storage oil is supplied to all the lubrication sites. On the other hand, when the temperature of the oil is higher than the specified temperature, fluid lubrication is performed. The heat storage oil may be supplied only to the lubricated part. Further, when the temperature of the oil is equal to or higher than a specified temperature, the heat storage oil may be supplied to a portion other than the lubricated portion where boundary lubrication is performed.

  Here, the specified temperature is the amount of reduction in the frictional force of the engine as a whole when the heat storage oil is supplied only to the lubrication part where fluid lubrication is performed and when the heat storage oil is supplied to all the lubrication parts. It is good also as the temperature of the oil at the time of reverse.

  Next, an oil supply method in the present embodiment will be described. The oil supply method described here is performed when the engine 1 is started.

  FIG. 3 is a diagram illustrating an oil supply state when the temperature of the oil is lower than a specified temperature. Oil does not flow through the oil passage 9 indicated by the broken line.

  The four-way valve 11a communicates all the passages connected to the four-way valve 11a. The three-way valve 11b selects the second heat storage oil passage 9e and connects it to the IN camshaft 2 and EX camshaft 3 side of the third oil passage 9c. Further, the three-way valve 11c selects the fourth heat storage oil passage 9g and connects it to the crankshaft 5 side of the second oil passage 9b.

  In this way, the heat storage oil is supplied from the heat storage container 10 to the valve operating system such as the IN camshaft 2 and the EX camshaft 3 through the first heat storage oil passage 9d and the second heat storage oil passage 9e. Further, the heat storage oil is supplied from the heat storage container 10 to the piston 4 through the first heat storage oil passage 9d, the third heat storage oil passage 9f, and the oil jet 8. Furthermore, the heat storage oil is supplied from the heat storage container 10 to the crankshaft 5 through the first heat storage oil passage 9d, the fourth heat storage oil passage 9g, and the second oil passage 9b.

  In this way, heat storage oil can be supplied to the crankshaft, piston ring, and valve train.

  Even in such a case, the oil passing through the oil filter 7 is supplied to other lubricating parts and parts where hydraulic control is performed.

  FIG. 4 is a diagram showing an oil supply state when the oil temperature is equal to or higher than a specified temperature. Oil does not flow through the oil passage 9 indicated by the broken line.

  The four-way valve 11a communicates only with the first heat storage oil passage 9d and the fourth heat storage oil passage 9g. The three-way valve 11b selects the oil filter 7 side of the third oil passage 9c and connects it to the IN camshaft 2 and EX camshaft 3 side of the third oil passage 9c. Further, the three-way valve 11c selects the fourth heat storage oil passage 9g and connects it to the crankshaft 5 side of the second oil passage 9b.

  By doing in this way, heat storage oil is supplied only from the heat storage container 10 to the crankshaft 5 through the first heat storage oil passage 9d, the fourth heat storage oil passage 9g, and the second oil passage 9b. Oil from the oil pan 1c is supplied to the valve operating system such as the IN camshaft 2 and the EX camshaft 3.

  As described above, the four-way valve 11a, the three-way valve 11b, and the three-way valve 11c are controlled depending on whether or not the temperature of the oil at the time of starting the engine is lower than the specified temperature. It becomes possible.

  Even in such a case, the oil passing through the oil filter 7 is supplied to other lubricating parts and parts where hydraulic control is performed.

  In this embodiment, regardless of fluid lubrication or boundary lubrication, when the temperature of the oil in the oil pan 1c is lower than the specified temperature, the heat storage oil is supplied to all the lubrication sites, while the specified temperature In the above case, the heat storage oil may be supplied only to the lubrication part where the effect of supplying the heat storage oil is high. Here, the “site with high effect” may be obtained in advance by experiments.

  In this embodiment, one specified temperature is provided and each valve is controlled depending on whether the temperature is lower than the specified temperature. Instead, a plurality of specified temperatures are provided. The heat storage oil may be supplied to different lubricating parts at the prescribed temperature. Furthermore, the relationship between the specified temperature and the lubrication site to which the heat storage oil is supplied may be obtained in advance by experiments or the like so that the frictional force of the engine as a whole is the lowest.

  In the present embodiment, when the oil temperature is equal to or higher than the specified temperature, the heat storage oil is supplied only to the crankshaft. If it is a site | part which can reduce a frictional force, you may supply thermal storage oil.

  As described above, according to the present embodiment, when the temperature of the oil is lower than the specified temperature, the heat storage oil is supplied to all the lubrication sites to reduce the frictional force of all the lubrication sites. Can do. On the other hand, when the temperature of the oil is higher than the specified temperature, the heat storage oil is supplied to all the lubrication parts by supplying the heat storage oil only to the lubrication parts (for example, the crankshaft) where the effect of supplying the heat storage oil is large. Rather, it is possible to reduce the frictional force of the entire engine. Thereby, it is possible to improve the startability of the engine and further improve the fuel consumption.

It is a figure which shows schematic structure of the engine which concerns on the Example of this invention. It is the figure which showed the relationship between the oil temperature and frictional force in a lubrication site | part. FIG. 2 (A) shows the relationship between the oil temperature and the frictional force at each lubrication site when the engine is started when the oil stored in the oil pan is lower than the specified temperature. Yes. FIG. 2B shows the relationship between the oil temperature and the frictional force when the engine is started when the oil stored in the oil pan is equal to or higher than a specified temperature. It is the figure which showed the oil supply state in case the temperature of oil is lower than the regulation temperature. It is the figure which showed the oil supply state in case the temperature of oil is more than regulation temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 1a Cylinder head 1b Cylinder block 1c Oil pan 2 Intake camshaft 3 Exhaust camshaft 4 Piston 5 Crankshaft 6a Oil pump 6b Electric pump 7 Oil filter 8 Oil jet 9 Oil passage 10 Heat storage container 11a Four-way valve 11b Three-way valve 11c Three-way Valve 12 Oil temperature sensor 13 ECU

Claims (3)

  A heat storage oil supply system for an internal combustion engine capable of supplying oil stored in a heat storage container to a plurality of lubrication parts at the time of starting the engine, depending on the engine temperature at the time of engine start, from the heat storage container to the plurality of lubrication parts A heat storage oil supply system for an internal combustion engine, comprising means for changing an oil supply ratio.   The lubrication site has a frictional force at the lubrication site that varies according to the engine temperature, and the frictional force varies from lubrication site to lubrication unit. The means for changing the supply ratio starts the oil stored in the heat storage container. Sometimes when only the lubrication part selected from a plurality of lubrication parts is supplied to the lubrication part rather than all lubrication parts, if the frictional force of the entire engine is reduced, heat is stored only in the selected lubrication part. 2. The heat storage oil supply system for an internal combustion engine according to claim 1, wherein oil is supplied from a container.   The plurality of lubrication parts include at least a part where boundary lubrication is performed, and the means for changing the supply ratio supplies oil to all the lubrication parts when the engine temperature is lower than a specified temperature, 3. The heat storage oil supply system for an internal combustion engine according to claim 1, wherein when the engine temperature is equal to or higher than a predetermined temperature, oil is supplied to a portion other than the portion where boundary lubrication is performed.

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