JP5061329B2 - In-oil diluted fuel separator for internal combustion engine - Google Patents

Description

  The present invention relates to an oil-in-oil diluted fuel separation device for an internal combustion engine, and more particularly, to an oil dilution in an internal combustion engine capable of efficiently separating fuel contained in lubricating oil of the internal combustion engine while suppressing deterioration of the oil. The present invention relates to a fuel separator.

2. Description of the Related Art Conventionally, an oil-in-oil diluted fuel separator for an internal combustion engine is known that evaporates and separates fuel contained in oil by heating the lubricating oil in order to suppress dilution due to fuel contamination of the lubricating oil (for example, Patent Document 1).
Patent Document 1 discloses that an oil heater is provided in the middle of an oil circuit of an internal combustion engine, and the lubricating oil flowing in the oil circuit is heated by this heater to vaporize and separate the fuel.
Further, Patent Document 2 discloses that a heater is provided at the bottom of the oil pan, and the lubricating oil in the oil pan is heated by this heater to vaporize and separate the fuel.

JP 2004-190513 A JP 2004-340056 A

  However, in Patent Document 1, a relatively large amount of lubricating oil that passes through an oil passage that connects the oil pan and the lubricated portion of the engine or a bypass passage provided in the oil passage is heated by a heater. Energy loss is large. Moreover, in the said patent document 2, since all the oil in an oil pan is heated, the above-mentioned problem becomes very remarkable.

  The present invention has been made in view of the above situation, and provides a diluted fuel separation apparatus for an internal combustion engine that can efficiently separate the fuel contained in the lubricating oil of the internal combustion engine while suppressing deterioration of the oil. The purpose is to provide.

The present invention is as follows.
1. Heating means for heating the lubricating oil of the internal combustion engine;
An oil storage section provided with a first chamber for storing lubricating oil heated by the heating means, and a second chamber partitioned from the first chamber so that the lubricating oil heated by the heating means can be introduced When,
An oil guide part provided in the main body of the internal combustion engine and for guiding lubricating oil that has lubricated a piston among the lubricated parts of the internal combustion engine to the first chamber;
An oil passage having an oil pump for supplying lubricating oil in the second chamber to the lubricated part is disposed in the second chamber ,
A raised portion that divides the oil reservoir into the first chamber and the second chamber is formed on the bottom wall of the oil reservoir, and the heating means uses the exhaust gas of the internal combustion engine as a heat source and the bump An oil-in-oil diluted fuel separator for an internal combustion engine, characterized in that it is a lower exhaust pipe that passes through a lower portion of the part .
2. The oil storage volume of the first chamber is smaller than the oil storage volume of the second chamber. The oil-diluted fuel separator for an internal combustion engine as described.
3. The heating means heats the lubricating oil flowing out from the first chamber to the second chamber. Or 2. 2. An oil-in-diluted fuel separator for an internal combustion engine according to 1.
4). The bottom wall of the oil reservoir is formed in a stepped shape so that the bottom wall constituting the first chamber is at a higher level than the bottom wall constituting the second chamber . To 3. An oil-in-oil diluted fuel separator for an internal combustion engine according to any one of the above.

According to the diluted fuel separation device for an internal combustion engine of the present invention, the lubricating oil that has lubricated the piston, which is the lubricated portion of the internal combustion engine, is guided to the first chamber of the oil reservoir by the oil guide and heated by the heating means. Thus, fuel vaporization is promoted. As described above, the lubricating oil in which a relatively large amount of fuel is mixed is introduced into the first chamber by the oil guide portion, and the lubricating oil containing a relatively large amount of the fuel is selectively heated. Even if it contains a lot of fuel, the fuel can be separated efficiently compared to the case where the lubricating oil is heated non-selectively and vaporized and separated, and the fuel contains a relatively large amount of fuel. By selectively heating the lubricating oil, it is possible to prevent the lubricating oil from being deteriorated more than necessary due to heating. In addition, since the lubricating oil that lubricated the piston does not flow directly into the second chamber, the lubricating oil supplied to the lubricated part can be made into a lubricating oil having a small viscosity decrease rate due to fuel dilution. The lubrication failure of the part can be prevented.
Further, since the heating means uses the exhaust gas of the internal combustion engine as a heat source, the fuel can be vaporized and separated from the lubricating oil using an existing heat source without newly providing a heat source for fuel separation.
Further, when the oil storage volume of the first chamber is smaller than the oil storage volume of the second chamber, the amount of lubricating oil stored in the first chamber and heated by the heating means is relatively small. The amount of lubricating oil stored in the second chamber that can be supplied to the lubricated portion can be relatively large. As a result, it is not necessary to secure a larger amount of lubricating oil than necessary while realizing efficient fuel separation.
Furthermore, when the heating means heats the lubricating oil flowing out from the first chamber to the second chamber, more efficient fuel separation can be realized for a smaller amount of lubricating oil, and the lubricating oil can be removed by heating. Unnecessary deterioration can be further suppressed.

  The oil-diluted fuel separator for an internal combustion engine according to the present embodiment includes a heating means, an oil reservoir, and an oil guide described below.

  As long as the “heating means” heats the lubricating oil of the internal combustion engine, its structure, heating mode, type of heat source, etc. are not particularly limited. Examples of the heating means include an exhaust pipe for exhausting exhaust gas from an internal combustion engine, and an electric heater. From the viewpoint that an existing heat source can be used, an exhaust pipe of an internal combustion engine is preferable.

  The “oil reservoir” includes a first chamber that stores lubricating oil heated by the heating unit, and a second chamber that is partitioned from the first chamber so that the lubricating oil heated by the heating unit can be introduced. As long as is provided, the structure, shape, material, partition form, etc. are not particularly limited. Examples of the oil reservoir include an oil pan provided at the lower part of the main body of the internal combustion engine, an oil tank provided separately from the main body of the internal combustion engine, and the like.

As the partition form of the first chamber and the second chamber, for example, (1) a form in which the bottom wall of the oil reservoir is raised and partitioned in a direction parallel to the axial direction of the crankshaft (FIG. 1, 3), (2) a configuration in which the bottom wall of the oil reservoir is raised and partitioned in a direction orthogonal to the axial direction of the crankshaft (see FIG. 2 and the like).
In the forms (1) and (2), for example, lubricating oil overflowing from the first chamber can be introduced into the second chamber over the upper edge of the raised bottom wall.

  Here, as the heating mode of the lubricating oil by the heating means, (1) a mode in which the entire lubricating oil stored in the first chamber is heated, and (2) a process in which the lubricating oil flows out from the first chamber to the second chamber. In the above, there can be mentioned a mode in which the lubricating oil flowing out is heated. From the viewpoint of realizing efficient fuel separation for a small amount of lubricating oil, the heating mode (2) is preferable.

An oil passage having an oil pump for supplying lubricating oil in the second chamber to a lubricated portion of the internal combustion engine is disposed in the second chamber.
When the oil reservoir is an oil pan, an oil strainer is usually provided on one end side of the oil passage, and the oil strainer is disposed in the oil pan.

Examples of the oil passage include one or a combination of two or more of piping, a passage formed in a main body or a mechanism portion of an internal combustion engine, a space, and the like.
Examples of the oil pump include a trochoid type, an internal gear type, an external gear type, and an inner gear type. This oil pump can be operated, for example, by a driving force of an internal combustion engine, or can be operated by a drive source different from the internal combustion engine.

Here, for example, the oil storage volume of the first chamber can be smaller than the oil storage volume of the second chamber. The ratio (C1 / C2) between the oil storage volume C1 of the first chamber and the oil storage volume C2 of the second chamber is preferably 0.2 to 0.5 (particularly 0.25 to 0.3). This is because fuel in a relatively small amount of lubricating oil can be more efficiently separated in the first chamber, and a large amount of lubricating oil can be secured in the second chamber.
Here, for example, the oil reservoir is formed in a stepped shape in the bottom wall of the oil reservoir, and the bottom wall constituting the first chamber is set at a higher level than the bottom wall constituting the second chamber. The storage volume can be made smaller than the oil storage volume of the second chamber.

The “oil guide part” is not particularly limited in its structure, shape, material, and the like as long as the lubricating oil that has lubricated the piston that is the lubricated part of the internal combustion engine is guided to the first chamber.
Along with the oil guide part, in the main body of the internal combustion engine, (a) lubricating oil formed in the cylinder block of the engine and returned to the oil storage part through a communication path connecting the crank chamber and the head cover. Another oil guide for guiding the oil to the second chamber is provided, or (b) Other oil guide for guiding the lubricating oil returned to the oil storage through the chain case or belt case of the engine to the second chamber A part can be provided. As a result, the lubricating oil in which the fuel is hardly mixed by the other oil guides can be guided and introduced into the second chamber, and the separation efficiency of the fuel in the lubricating oil in the first chamber can be further improved. From the viewpoint of further improving the separation efficiency, a combination of the above forms (a) and (b) is preferable.

  In the embodiments (1) and (2), for example, (a) the second chamber is formed in a cylinder block of the engine and is disposed directly below a communication path that connects the crank chamber and the inside of the head cover. ) The second chamber may be arranged directly under the chain case or the belt case of the engine. As a result, the lubricating oil in which almost no fuel is mixed can be dropped and introduced into the second chamber, and the separation efficiency of the fuel in the lubricating oil in the first chamber can be further improved. From the viewpoint of further improving the separation efficiency, a combination of the above forms (a) and (b) is preferable.

  Examples of the “lubricated part of the internal combustion engine” include, for example, a crankshaft, a connecting rod, a camshaft, and a drive system in addition to the piston. Among these, a relatively large amount of fuel that leaks from a gap in the cylinder inner wall surface of the piston is mixed in the lubricating oil that lubricates the crankshaft, the connecting rod, the piston, and the like and returns to the oil reservoir. On the other hand, almost no fuel is mixed in the lubricating oil that circulates through the camshaft, drive system, etc. and is returned to the oil reservoir. Also, the lubricating oil that lubricates the periphery of the piston is usually returned to the oil reservoir through a gap between the piston and the cylinder. On the other hand, the lubricating oil that lubricates the surroundings of the head is usually returned to the oil reservoir through a communication path that is formed in the cylinder block and cylinder head of the engine and connects the crank chamber and the space in the head cover. Or returned to the oil reservoir through the case or belt case.

  In a cylinder injection internal combustion engine, in addition to the main injection that injects fuel into the cylinder near the compression top dead center, the sub-injection that injects fuel into the cylinder before and after the main injection (for example, pilot injection, When performing post injection or the like, the injected fuel is likely to adhere to the inner wall surface of the cylinder, and the attached fuel is likely to be mixed into the lubricating oil. Accordingly, the oil-in-diluted fuel separation device for an internal combustion engine according to this embodiment can be suitably used as an oil-diluted fuel separation device for an in-cylinder injection type internal combustion engine that performs sub-injection before and after main injection.

Hereinafter, the present invention will be specifically described with reference to the drawings.
In this embodiment, as an “internal combustion engine” according to the present invention, an in-cylinder injection engine that performs sub-injection before and after the main injection is illustrated.

(1) Engine Configuration As shown in FIG. 1, the engine 1 according to the first embodiment includes a cylinder block 1a in which a cylinder 2 is formed, and a cylinder head 1b fixed to the upper portion of the cylinder block 1a. ing. A piston 3 is supported in the cylinder 2 of the cylinder block 1a so as to be able to reciprocate. In addition, a crankcase 1c configured to rotatably support the crankshaft 4 is fixed to the lower portion of the cylinder block 1a. The crankshaft 4 is connected to the piston 3 via a connecting rod 5. A combustion chamber 6 surrounded by the top surface of the piston 3, the wall surface of the cylinder head 1b, and the wall surface of the cylinder 2 is formed above the piston 3.

  The cylinder head 1b has an intake port 8a having one end connected to the intake pipe 7a and the other end connected to the combustion chamber 6, and one end connected to the exhaust pipe 7b and the other end connected to the combustion chamber 6. The exhaust port 8b is formed. The cylinder head 1b is provided with an intake valve 9a for opening and closing the intake port 8a and an exhaust valve 9b for opening and closing the exhaust port 8b, and camshafts 10a and 10b for driving the intake valve 9a and the exhaust valve 9b, respectively. It is supported rotatably. Further, a cylinder head cover 1d that covers the valve mechanism is attached to the upper portion of the cylinder head 1b. One end side of the intake pipe 7 a is connected to the air cleaner box 11. In the middle of the intake pipe 7a, a throttle valve 12 for adjusting the amount of intake air flowing through the intake pipe 7a is provided.

  The space 13 in the cylinder head cover 1d is connected through the PCV valve 15a to the other end of the first return path 15 whose one end is connected to the downstream side of the throttle valve 12 of the intake pipe 7a. Further, the space 13 in the cylinder head cover 1d is connected to the other end side of the second return path 16 whose one end side is connected to the upstream side of the throttle valve 12 of the intake pipe 7a.

  An oil pan 17 (illustrated as an “oil storage portion” according to the present invention) for storing lubricating oil is attached to the lower portion of the crankcase 1c. The oil pan 17 and the lubricated part of the engine 1 are connected via an oil circulation path (not shown) including an oil passage 18.

(2) Configuration of the oil-diluted fuel separator The oil-diluted fuel separator 20 according to the first embodiment includes an oil pan 17 that stores lubricating oil, as shown in FIG. The bottom wall of the oil pan 17 is formed with a raised portion 17 a that is raised in a cross-section arc shape along a linear direction parallel to the axial direction of the crankshaft 4. The oil pan 17 is partitioned into a first chamber 21 and a second chamber 22 by the raised portion 17a. Further, the bottom wall of the oil pan 17 is provided at a position where the bottom wall on the first chamber 21 side is higher than the bottom wall on the second chamber 22 side. The oil storage volume C1 of the first chamber 21 is set to about 1.2 l, and the oil storage volume C2 of the second chamber 22 is set to about 4 l. Therefore, the ratio (C1 / C2) between the oil storage volume C1 of the first chamber 21 and the oil storage volume C2 of the second chamber 22 is set to 0.3.
A lower exhaust pipe 23 for discharging exhaust gas of the engine 1 (illustrated as a heating means according to the present invention) is passed under the raised portion 17a and outside the main body of the engine 1.

  An oil strainer 18 a provided on one end side of the oil passage 18 is disposed in the second chamber 22. An oil pump 18 b for supplying the lubricating oil in the second chamber 22 to the lubricated part of the engine 1 is provided in the middle of the oil passage 18. The second chamber 22 is formed in the cylinder block 1a and the cylinder head 1b of the engine 1 and is disposed immediately below a communication path 24 that connects the crank chamber 14 and the space 13 in the cylinder head cover 1d.

  A plate-like baffle plate 25 that guides the lubricating oil returned to the oil pan 17 through the gap between the piston 3 and the cylinder 2 to the first chamber 21 below the crankcase 1 c and above the oil pan 17. Is provided.

(3) Operation of the oil-in-diluted fuel separation device Next, the operation of the oil-in-diluted fuel separation device 20 having the above configuration will be described.
In the present embodiment, the cylinder injection engine 1 that performs the sub-injection before and after the main injection is employed, so that the fuel adhering to the inner peripheral surface of the cylinder is mixed with the lubricating oil and the gap between the piston 3 and the cylinder 2 The fuel dilution rate in the lubricating oil that passes through and returns to the oil pan 17 increases.

During engine operation, lubricating oil that circulates around the pistons such as the crankshaft 4, the connecting rod 5, and the piston 3 serving as a lubricated portion of the engine 1 passes through the gap between the piston 3 and the cylinder 2 to the baffle plate 25. It is guided and returned into the first chamber 21 of the oil pan 17. On the other hand, the lubricating oil that circulates around the heads of the camshafts 10a and 10b and the drive system as the lubrication parts of the engine 1 is returned to the second chamber 22 of the oil pan 17 through the communication path 24, or 1 is returned to the second chamber 22 of the oil pan 17 through a chain case or a belt case (not shown).
The lubricating oil which is guided and stored in the first chamber 21 by the baffle plate 25 and overflows from the first chamber 21 climbs over the upper edge of the raised portion 17a provided on the bottom wall of the oil pan 17, and moves into the second chamber 22 chamber. To be introduced. At this time, the lubricating oil overflowing along the wall surface of the raised portion 17a is heated by the radiant heat of the exhaust gas passing through the lower exhaust pipe 23 passing through the lower portion of the raised portion 17a, and the fuel mixed in the lubricating oil is vaporized. .

  On the other hand, the lubricating oil that has lubricated the lubricated part but does not fall on the baffle plate 25, that is, the lubricated part such as the camshafts 10a, 10b on the upper part of the engine 1, is lubricated, and the communication path 24 from the cylinder head cover 1d is obtained. Lubricating oil or the like that is returned to the oil pan 17 through the first is introduced directly into the second chamber 22 without passing through the first chamber 21. Then, the lubricating oil that has reached the second chamber 22 is sucked into the oil strainer 18 a, pumped by the oil pump 18 b, and sent again to each lubricated portion of the engine 1 through the oil passage 18.

The vaporized fuel is mixed with blow-by gas and sent from the crank chamber 14 to the space 13 in the cylinder head cover 1d through the communication path 24. The blow-by gas is recirculated to the intake pipe 7a through the first return path 15 in a low-load operation state of the engine 1 (an operation state in which the throttle valve is open), and the engine 1 is in a high-load operation state (throttle valve operation). In an operation state where the opening degree is large), the refrigerant is recirculated to the intake pipe 7a via the second recirculation path 16 in addition to the first recirculation path 15.
When the engine 1 is in a low load operation state, fresh air flowing upstream of the throttle valve 12 of the intake pipe 7a via the second return path 16 is sucked into the space 13 in the cylinder head cover 1d and blow-by in the space 13 is blown. Gas will be ventilated.

(4) Effects of the Embodiment As described above, in this embodiment, the lubricating oil that has lubricated the piston 3 that is the lubricated portion of the engine 1 is guided into the first chamber 21 of the oil pan 17 by the baffle plate 25, and Stored in one chamber 21. The lubricating oil stored in the first chamber 21 is introduced into the second chamber 22 chamber over the upper edge of the raised portion 17 a provided on the bottom wall of the oil pan 17. At this time, the lubricating oil is heated by the lower exhaust pipe 23 to promote fuel vaporization. Thus, the lubricating oil mixed with a relatively large amount of fuel is introduced into the first chamber 21 by the baffle plate 25, and the lubricating oil containing a relatively large amount of the fuel is selectively heated. The fuel can be separated more efficiently than when the fuel is vaporized and separated by non-selective heating of the lubricating oil regardless of whether or not it contains a lot of fuel. Deterioration as described above can be suppressed.

  Further, in this embodiment, the lubricating oil that has lubricated the piston 3, that is, the lubricating oil containing a relatively large amount of fuel, does not flow directly into the second chamber 22, so that it is supplied to the lubricated part. The lubricating oil can be made into a lubricating oil having a small viscosity reduction rate due to fuel dilution, and poor lubrication of the lubricated part can be prevented.

  Further, in the present embodiment, the second chamber 22 is disposed directly below a communication path 24 formed in the cylinder block 1a and the cylinder head 1b of the engine 1 and connecting the crank chamber 14 and the space 13 in the cylinder head cover 1d. Therefore, the lubricating oil in which almost no fuel is mixed can be dropped and introduced into the second chamber 22 through the communication path 24, and the separation efficiency of the fuel in the lubricating oil in the first chamber 21 can be further improved. At the same time, the lubricating oil supplied to the lubricated part can be a lubricating oil having a small viscosity reduction rate due to fuel dilution, and the lubrication failure of the lubricated part can be prevented.

  In this embodiment, since the oil storage volume of the first chamber 21 is smaller than the oil storage volume of the second chamber 22, the lubricating oil stored in the first chamber 21, that is, stored for heating. The amount of lubricating oil stored can be made relatively small, and the amount of lubricating oil stored in the second chamber 22 that can be supplied to the lubricated part can be made relatively large. As a result, it is not necessary to secure a larger amount of lubricating oil than necessary while realizing efficient fuel separation.

Further, in the present embodiment, the lower exhaust pipe 23 heats the lubricating oil flowing out from the first chamber 21 to the second chamber 22, so that more efficient fuel separation for a smaller amount of lubricating oil is performed. It can be realized and further deterioration of the lubricating oil due to heating can be further suppressed.
Further, in this embodiment, the lower exhaust pipe 23 that discharges the exhaust gas of the engine 1 is used as the heating means. Therefore, a lubricating oil using an existing heat source is provided without newly providing a heat source for fuel separation. It is possible to achieve fuel vapor separation from the fuel.

  In the present invention, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in the above embodiment, the first chamber 21 and the second chamber 22 are partitioned in a linear direction parallel to the axial direction of the crankshaft 4 of the engine 1, but the present invention is not limited to this. For example, FIG. As shown, the first chamber 21 and the second chamber 22 may be partitioned in a linear direction orthogonal to the axial direction of the crankshaft 4. In addition, in the above, the engine 1 has a chain 26 that transmits its power to the camshafts 10 a, 10 b, etc. on the shaft end side of the crankshaft 4, and the lubricating oil that lubricates the chain 26 circulates to the oil pan 17. When the chain case 27 is provided, the second chamber 22 is provided on the chain case 27 side, and lubricating oil containing almost no fuel returning to the oil pan 17 through the chain case 27 is directly supplied to the second chamber 22. Can be introduced.

  In the above embodiment, the lubricating oil overflowing from the first chamber 21 and flowing into the second chamber 22 is heated. However, the present invention is not limited to this. For example, the entire lubricating oil stored in the first chamber 21 is You may make it heat.

  In the above-described embodiment, the lower exhaust pipe 23 is exemplified as the heating unit. However, the present invention is not limited to this. For example, an electric heater 23 ′ including a heating wire 23 ′ a may be employed as the heating unit. Also in this case, the lubricating oil that overflows from the first chamber 21 and flows out to the second chamber 22 may be heated, and the lubricating oil stored in the first chamber 21 as shown in FIG. The whole may be heated.

  It is widely used as a technique for separating diluted fuel contained in lubricating oil of an internal combustion engine. In particular, it is suitably used as an in-oil diluted fuel separator for a direct injection internal combustion engine that performs sub-injection before and after main injection.

It is explanatory drawing which shows the in-oil dilution fuel separation apparatus which concerns on an Example. It is explanatory drawing which shows the dilution fuel separation apparatus in oil of another form. It is explanatory drawing which shows the dilution fuel-in-oil separation apparatus of other form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Engine, 1a; Cylinder block, 1b; Cylinder head, 1c; Crankcase, 1d; Cylinder head cover, 2; Cylinder, 3; Piston, 4; Crankshaft, 5: Connecting rod, 6: Combustion chamber, 7a; Exhaust pipe, 8a; Intake port, 8b; Exhaust port, 9b; Intake valve, 9b; Exhaust valve, 10a, 10b; Camshaft, 11; Air cleaner box, 12: Throttle valve, 13; Space, 14; Crank chamber, 15; first return passage, 15a; PCV valve, 16; second return passage, 17; oil pan, 17a; raised portion, 18; oil passage, 18a; oil strainer, 18b; Medium dilution fuel separator, 21; first chamber, 22; second chamber, 23; lower exhaust pipe, 23 '; electric heater, 23'a; 24; connecting passage, 25; baffle plate, 26; chain, 27; chain case.

Claims (4)

Heating means for heating the lubricating oil of the internal combustion engine;
An oil storage section provided with a first chamber for storing lubricating oil heated by the heating means, and a second chamber partitioned from the first chamber so that the lubricating oil heated by the heating means can be introduced When,
An oil guide part provided in the main body of the internal combustion engine and for guiding lubricating oil that has lubricated a piston among the lubricated parts of the internal combustion engine to the first chamber;
An oil passage having an oil pump for supplying lubricating oil in the second chamber to the lubricated part is disposed in the second chamber ,
A raised portion that divides the oil reservoir into the first chamber and the second chamber is formed on the bottom wall of the oil reservoir, and the heating means uses the exhaust gas of the internal combustion engine as a heat source and the bump An oil-in-oil diluted fuel separator for an internal combustion engine, characterized in that it is a lower exhaust pipe that passes through a lower portion of the part .   The oil-diluted fuel separator for an internal combustion engine according to claim 1, wherein the oil storage volume of the first chamber is smaller than the oil storage volume of the second chamber.   3. The diluted fuel separation apparatus for an internal combustion engine according to claim 1, wherein the heating unit heats the lubricating oil flowing out from the first chamber to the second chamber. 4. The bottom wall of the oil reservoir is formed in a stepped shape so that the bottom wall constituting the first chamber is at a higher level than the bottom wall constituting the second chamber . The oil-in-diluted fuel separator for an internal combustion engine according to one item.

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