JP2006183615A - Engine controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine controller capable of avoiding the seizure of an engine due to shortage of lubricant even if the amount of a fuel is almost brought into an empty state in a light oil fuel lubricating engine in which the fuel such as light oil is also used as a lubricating oil. <P>SOLUTION: This engine controller 10 of the engine 2 in which the fuel such as the light oil is also used as the lubricating oil comprises a lubrication system fuel circulating circuit and an injection system fuel circulating circuit. Also, the engine controller comprises a fuel residual amount detection means 3a detecting the residual amount of fuel in a fuel tank 3 and a bypass passage 6 feeding the fuel from the fuel tank 3 directly to a direct injection pump 5 after bypassing a lubrication pump 4. When the fuel residual amount detection means 3a indicates a prescribed value or below, the flow of the fuel from the lubrication pump 4 to the injection pump 5 is cut off by a selector valve 7 to separate the lubrication system fuel circulating circuit from the injection system fuel circulating circuit so that the fuel can be circulated by the lubrication system fuel circulating circuit only. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine control device for a fuel lubricated engine such as light oil that uses fuel such as light oil as a lubricating oil, and in particular, to control the supply of fuel when the fuel approaches an empty state. The present invention relates to a possible engine control device.

Conventionally, a light oil lubricated diesel engine in which a reservoir for separating bubbles is disposed between a fuel tank and a diesel engine, and a lubrication system fuel circulation circuit and a combustion system fuel circulation circuit are configured between the reservoir and the engine. Is disclosed (Patent Document 1). In such a light oil lubricated diesel engine, light oil as a fuel is also used as a lubricant for each part of the engine and circulates through each part of the engine. For this reason, the oil only for lubrication is unnecessary, and the effort of oil replacement can be saved.
JP 60-194112 A

However, in the light oil lubricated diesel engine as described above, the consumption of the fuel in the fuel tank due to the in-cylinder explosion simultaneously decreases the lubricating oil, so when the fuel is consumed and approaches the empty state, There is a possibility that sufficient fuel (lubricating oil) is not supplied to the fuel circulation circuit and the fuel does not reach the sliding portions in the engine. If the fuel, that is, the lubricating oil, does not reach the sliding portions in the engine, the engine seizure occurs, which is a problem.
Such means for avoiding the problem of engine burn-in when the fuel is in an empty state is not disclosed in Patent Document 1.

  Accordingly, the present invention provides an engine control device that avoids the above-described problems in a fuel-lubricated engine such as light oil and does not cause engine burn-in even when the fuel approaches an empty state. This is the issue.

  In order to achieve the above object, an engine control device according to the present invention is an engine control device for controlling fuel supply of a fuel lubricated engine such as light oil that uses fuel such as light oil as a lubricating oil, and is provided from a fuel tank by a lubrication pump. A lubrication system fuel circulation circuit for supplying fuel to each part of the engine, an injection system fuel circulation circuit for supplying fuel to the fuel injection system from the lubrication pump via an injection pump, a fuel remaining amount detection means in the fuel tank, A bypass passage for bypassing the lubrication pump and supplying fuel from the fuel tank to the injection pump; and a fuel flow path switching for shutting off fuel from the lubrication pump to the injection pump and allowing fuel to flow through the bypass passage And when the fuel remaining amount detecting means shows a predetermined value or less, the fuel flow path switching means removes the lubrication pump from the lubrication pump. Blocking the flow of fuel to the serial injection pump, the fuel in the fuel tank is supplied to the injection pump through the bypass passage, and characterized in that to continue driving of the lubricant pump.

  In such a fuel supply device, an oil tank is interposed between the fuel tank and the lubrication pump, the lubrication pump supplies fuel from the oil tank, and the bypass passage supplies fuel from the fuel tank. It can be set as the structure to do.

  By adopting such a configuration, when the fuel remaining amount detecting means shows a predetermined value or less, that is, when the fuel in the fuel tank approaches an empty state, the lubrication system fuel circulation circuit and the injection system fuel It can be separated from the circulation circuit. By separating the lubrication system fuel circulation circuit and the injection system fuel circulation circuit, while the remaining fuel in the fuel tank is consumed by in-cylinder explosion, the lubricating fuel stored in the oil tank is consumed. It can be circulated in the same way as conventional engine oil to prevent engine burn-in.

  According to the present invention, when the fuel remaining amount detecting means shows a predetermined value or less, the fuel flow switching means interrupts the flow of fuel from the lubrication pump to the injection pump and allows the fuel in the fuel tank to pass through the bypass passage. Since the fuel is supplied to the injection pump and the lubrication pump is continuously driven so that the fuel is circulated through the lubrication system fuel circulation circuit, the fuel that acts as the lubricating oil even when the fuel is nearly empty Can be continuously circulated in the lubricating fuel circulation circuit. Thereby, engine burn-in can be prevented.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a vehicle 1 equipped with an engine control device 10 of the present invention. A schematic configuration of the engine control device 10 mounted on the vehicle 1 will be described with reference to FIG. The vehicle 1 is equipped with an engine 2 that uses light oil as fuel, a fuel tank 3, a lubrication pump 4, and an injection pump 5 that supplies fuel to the fuel injection system via the lubrication pump 4. Yes. A bypass passage 6 that bypasses the lubrication pump 4 and supplies fuel from the fuel tank 3 to the injection pump 5 and a switching valve 7 that is positioned between the lubrication pump 4 and the injection pump 5 are provided. This switching valve 7 corresponds to the fuel flow path switching means in the present invention, interrupts the flow of fuel from the lubrication pump 4 to the injection pump 5 and allows the fuel from the fuel tank 3 to flow in the bypass passage 6. Have a role.
The engine control device 10 is further provided with a return path 16 for returning the fuel injected by the injection pump 5 to the fuel tank 3 again.

  A more specific configuration of the engine control device 10 whose schematic configuration has been described above will be described with reference to FIG. The engine control device 10 includes a fuel tank 3 and an oil tank 9, both of which are connected by a pipe 11 including a supply pump 8. By operating the supply pump 8, the fuel in the fuel tank 3 is supplied into the oil tank 9. The fuel in the oil tank 9 is sucked up by the lubrication pump 4, passes through the filter 12, and is supplied as a lubricant to the engine parts 13. The fuel supplied to each part 13 of the engine flows down in the engine 2 and returns to the oil tank 9 again as indicated by an arrow 14. That is, the engine control device 10 includes a lubrication system fuel circulation circuit including a fuel tank 3, a supply pump 8, an oil tank 9, a lubrication pump 4, engine parts 13, and an oil tank 9 again.

  Further, the engine control device 10 has a switching valve 7 and an injection pump 5 on the downstream side of the lubrication pump 4, and supplies fuel to a fuel injection system 15 located on the downstream side of the injection pump 5. ing. Further, a return path 16 is provided for returning the fuel that has not been used for combustion in the fuel injection system to the fuel tank 3 again as indicated by an arrow 17. In other words, the engine control device 10 includes a fuel tank 3, a supply pump 8, an oil tank 9, a lubrication pump 4, a switching valve 7, an injection pump 5, a fuel injection system 15, a return path 16, and a fuel tank 3 again. It has a circuit. The fuel injection system 15 includes a common rail (not shown) that receives fuel supplied from the injection pump 5 and a fuel injection valve (injector). Further, the engine control device 10 includes a bypass passage 6 in which one end is disposed in the fuel in the fuel tank 3 and the other end is connected to the switching valve 7.

Further, the fuel tank 3 is equipped with a level gauge 3a that corresponds to the fuel remaining amount detecting means of the present invention and that monitors the fuel remaining amount in the fuel tank 3. The level gauge 3a is connected to the ECU 21. The ECU 21 is also connected to the supply pump 8 and the switching valve 7. Such an ECU 21 sends a command to the switching valve 7 based on the value indicated by the level gauge 3a to switch the fuel flow path. Further, the driving and stopping of the supply pump 8 are switched in accordance with such switching of the fuel flow path.
The lubrication pump 4 is driven when the engine 2 is started, and the driving state is continued when the engine 2 is in an operating state. That is, when the engine 2 is in an operating state, fuel as a lubricant is supplied to each part 13 of the engine.

  The operating state of the engine control apparatus 10 configured as described above will be described with reference to FIGS. FIG. 3 illustrates a state in which fuel is sufficiently present in the fuel tank 3, and FIG. 4 illustrates a state in which the fuel in the fuel tank 3 is consumed and is nearly empty.

  As shown in FIG. 3, when the oil level 22 of the fuel in the fuel tank 3 is at a sufficiently high position, the ECU 21 acquires information that the fuel is not in an empty state from the level gauge 3a. When receiving such information from the level gauge 3a, the ECU 21 issues a drive command to the supply pump 8 and permits the switching valve 7 to flow from the lubrication pump 4 to the injection pump 5, A command is issued to shut off the fuel flow in the bypass passage 6.

  When the ECU 21 issues such a command, the engine control apparatus 10 forms a fuel path as shown by a thick line in FIG. That is, by driving the supply pump 8, the fuel in the fuel tank 3 is supplied into the oil tank 9 through the pipe 11. The fuel in the oil tank 9 is sucked up by the lubrication pump 4 driven by the rotation of the engine 2, passes through the filter 12, and is supplied to each part 13 of the engine as lubricating oil. Thereby, the friction of each part 13 of an engine is reduced, and the engine 2 is prevented from being seized. The fuel supplied to each engine part 13 flows down inside the engine 2 and returns to the oil tank 9 again.

  Further, the fuel sucked up by the lubrication pump 4 is allowed to flow between the lubrication pump 4 and the injection pump 5 by the switching valve 7, so that it is branched from the fuel supplied to each part 13 of the engine. And supplied to the injection pump 5. The fuel supplied to the injection pump 5 is supplied to a common rail constituting the fuel injection system 15, and high-pressure fuel is supplied to the combustion of the engine 2 through the injector. The fuel that has not been used for combustion is returned to the fuel tank 3 again as indicated by an arrow 17 through the return path 16.

  Next, as shown in FIG. 4, the case where the fuel in the fuel tank 3 is consumed and the state becomes nearly empty will be described. As shown in FIG. 4, when the oil level 22 of the fuel in the fuel tank 3 falls below the position of the level gauge 3a, the ECU 21 acquires information that the fuel is in an empty state from the level gauge 3a. When such information is received from the level gauge 3a, the ECU 21 issues a drive stop command to the supply pump 8 and interrupts the flow from the lubrication pump 4 to the injection pump 5 to the switching valve 7. Then, a command is issued to permit the fuel flow in the bypass passage 6.

  When the ECU 21 issues such a command, the engine control apparatus 10 forms a fuel path as shown by a thick line in FIG. That is, the drive of the supply pump 8 is stopped, the switching valve 7 blocks the flow from the lubrication pump 4 to the injection pump 5 and permits the flow of fuel in the bypass passage 6. The lubrication system fuel circulation circuit for supplying fuel and the injection system fuel circulation circuit for supplying fuel to the fuel injection system 15 are completely separated.

  In such a state, the lubrication system fuel circulation circuit is supplied with only the fuel stored in the oil tank 9 by the lubrication pump 4 driven by the rotation of the engine 2 until the filter 12, the lubrication pump 4, Each part of the engine 13 circulates again as an oil tank 9. In this way, the lubrication system forms an independent circulation circuit in the same manner as the conventional engine, so that regardless of the amount of fuel in the fuel tank 3, the engine 2 can be used as a lubricant until the engine 2 is completely stopped. Fuel continues to be supplied. Thereby, the burning of the engine 2 can be prevented.

  On the other hand, the fuel in the fuel tank 3 can continue to be supplied to the injection system fuel circulation circuit through the bypass passage 6 until the fuel tank 3 is completely empty, and traveling can be continued.

The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.
For example, a hybrid vehicle can be configured by combining an electric motor and an engine incorporating the engine control device of the present invention, which also uses fuel as a lubricating oil.

It is a mimetic diagram of a vehicle carrying an engine control device of the present invention. It is a block diagram which shows schematic structure of an engine control apparatus. It is explanatory drawing which shows the distribution route of the fuel before the fuel in a fuel tank approaches an empty state. It is explanatory drawing which shows the distribution route of fuel when the fuel in a fuel tank approaches an empty state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Fuel tank 3a Level gauge 4 Lubrication pump 5 Injection pump 6 Bypass passage 7 Switching valve 8 Supply pump 9 Oil tank 10 Engine control device 11 Pipe 12 Filter 13 Engine parts 15 Fuel injection system 16 Return path 21 ECU
22 Oil level

Claims (2)

An engine control device for controlling fuel supply of a fuel lubrication engine such as light oil that uses fuel such as light oil as a lubricating oil,
A lubrication system fuel circulation circuit for supplying fuel from a fuel tank to each part of the engine by a lubrication pump;
An injection system fuel circulation circuit for supplying fuel to the fuel injection system from the lubrication pump via the injection pump;
Fuel remaining amount detecting means in the fuel tank;
A bypass passage for bypassing the lubrication pump and supplying fuel from the fuel tank to the injection pump;
Fuel flow path switching means for blocking the flow of fuel from the lubrication pump to the injection pump and flowing the fuel to the bypass passage;
With
When the fuel remaining amount detecting means shows a predetermined value or less, the fuel flow switching means interrupts the flow of fuel from the lubrication pump to the injection pump, and the fuel in the fuel tank passes through the bypass passage. An engine control apparatus characterized in that the lubrication pump is continuously driven while being supplied to the injection pump. The fuel supply device according to claim 1, wherein
An engine control comprising an oil tank interposed between the fuel tank and the lubrication pump, wherein the lubrication pump supplies fuel from the oil tank, and the bypass passage supplies fuel from the fuel tank. apparatus.

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