Engine starting device, engine starting method, engine, and engine generator

Abstract

To provide an engine starting device that has a simple configuration and reduces fuel consumption when starting the engine. [Solution] A starting device 100 for engine E that starts with butane gas 3 and operates normally with kerosene 4, comprising a vacuum valve 8 configured to supply butane gas 3, a carburetor 5 configured to supply kerosene 4, a throttle SV provided on the carburetor 5, and a control device, wherein when starting engine E, the control device controls the opening S of the throttle SV of engine E to opening S1 so that the intake vacuum of engine E acts on the vacuum valve 8 to supply butane gas 3 to engine E, and kerosene 4 is not supplied to the carburetor 5 of engine E, and only butane gas 3 is supplied to the intake pipe 6 of engine E, thereby starting engine E.

Description

[Technical Field]

[0001] The present invention relates to an engine starting device, an engine starting method, an engine, and an engine generator. [Background technology]

[0002] There are kerosene engines that use kerosene, which is stockpiled in relatively large quantities as fuel for agricultural and residential heating. Kerosene has a low volatile content, making it difficult to start the engine when it is cold. Therefore, there are so-called heterogeneous fuel engines that use gasoline as starting fuel and kerosene as the normal fuel to start the engine.

[0003] Gasoline can deteriorate if stored for a long period of time. In engines that use gasoline as starting fuel or main fuel, there is a risk that the engine will not be able to start if the gasoline has deteriorated, for example, in the event of a disaster. To address this issue, there are kerosene engines that use LPG as starting fuel. For example, Patent Document 1 discloses a starting device for kerosene engines that uses LPG to start a kerosene engine that runs on kerosene. The kerosene engine starting device disclosed in Patent Document 1 interlocks the choke valve and the carburetor fuel on-off valve, and at start-up, the choke valve and the carburetor kerosene supply on-off valve are closed, so that the kerosene engine is started using only LPG. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-187353 Summary of the Invention [Problem to be solved by the invention]

[0005] In the kerosene engine starting device disclosed in Patent Document 1, the choke valve, which is linked to the fuel on-off valve, must be manually closed to start the engine, and after the engine has started, the choke valve must be manually opened. Furthermore, the choke valve must be manually opened to warm up the engine. Because the choke valve must be operated manually, forgetting to operate the choke valve will result in the engine continuing to run on LPG alone, resulting in increased LPG consumption.

[0006] An object of the present invention is to provide an engine starting device that has a simple configuration and reduces the consumption of fuel required to start the engine. [Means for solving the problem]

[0007] In order to achieve the above object, the starting device of the present invention is a starting device for an engine that starts with a first fuel and normally operates with a second fuel, and includes a vacuum valve configured to supply the first fuel, a carburetor configured to supply the second fuel, a throttle provided in the carburetor, and a control device, and when starting the engine, the control device controls the opening of the throttle of the engine to a predetermined opening so that the intake vacuum of the engine acts on the vacuum valve to supply the first fuel to the engine, and the second fuel is not supplied to the carburetor of the engine, and only the first fuel is supplied to the intake pipe of the engine, thereby starting the engine. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an engine starting device that has a simple configuration and reduces the consumption of engine starting fuel. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a starting device 100 according to an embodiment of the present invention. [Figure 2] 1 is a control diagram of a starting device 100 according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, an engine starting device, an engine starting method, an engine, and an engine generator according to an embodiment of the present invention will be described with reference to FIG.

[0011] Gasoline-fueled engine generators used as emergency engine generators can deteriorate if the engine is not operated for a long period of time, potentially rendering the generator unusable in the event of a natural disaster or emergency. This requires regular operation of the engine generator or the management of gasoline fuel, resulting in unnecessary fuel consumption. To address this issue, kerosene engines are available, which run on kerosene, a fuel relatively abundantly stockpiled for agricultural use or home heating. Kerosene has no expiration date, can be stored for long periods, and is relatively abundantly stockpiled, making it easy to use in the event of a natural disaster or emergency. However, because kerosene is a fuel with low volatile components, it is extremely difficult to start an engine using kerosene alone.

[0012] Therefore, a starting device 100 of the present invention is disclosed that uses butane gas 3 as the engine starting fuel to easily start a kerosene engine. Figure 1 is a schematic diagram of a starting device 100 for an engine E according to an embodiment of the present invention. Note that the main parts of the present invention will be described in detail, and explanations of other parts will be simplified or omitted.

[0013] The engine E according to the embodiment and a starting device 100 mounted on the engine E will now be described. The engine E includes a cylinder 1 (first tank) configured to store butane gas 3 (or isobutane gas or propane gas) as a first fuel, and a fuel tank 2 (second tank) configured to store kerosene 4 (or diesel, biodiesel, or biodiesel blend fuel) as a second fuel. The engine E also includes a carburetor 5 configured to supply kerosene 4 to an intake pipe 6 of the engine E, a throttle SV, a starter device (not shown) (recoil starter or starter motor), and a temperature sensor TS for measuring the temperature of the engine E. The temperature sensor TS is located in the engine head. The cylinder 1 may be a gas cartridge used in a portable stove. The starting device 100 according to the embodiment does not include a so-called choke valve for throttling the intake air volume. The carburetor 5 includes a supply portion 5a, a drain portion 5b, a float chamber 5c, and a throttle SV. The throttle SV is located downstream of the supply portion 5a.

[0014] First, the supply of butane gas 3, which is the starting fuel for engine E, will be described. Butane gas 3 is supplied to the intake pipe 6 downstream of the throttle SV of the carburetor 5, near engine E, via a vacuum valve 8 (vacuum valve) configured to open under the intake vacuum of engine E. The vacuum valve 8 is a diaphragm vacuum valve that opens and closes in response to the intake vacuum generated in the intake pipe 6 by cranking engine E. A vacuum line 7 is connected from the intake pipe 6 to the vacuum valve 8, and timing is measured based on the vacuum pressure in this vacuum line 7, which also operates the vacuum valve 8. An electrically controlled normally-open control valve V1 (first valve) is connected to the vacuum line 7. This control valve V1 controls the intake vacuum supplied to the vacuum valve 8, preventing the vacuum valve 8 from being turned on and off accidentally, thereby improving durability and reliability. A gas regulation line 11 is connected to one side of the negative pressure valve 8, and a regulator 9, a vaporizer 10, and a cylinder 1 are connected to the gas regulation line 11.

[0015] A gas supply line 12 for supplying butane gas 3 to the intake pipe 6 is connected to the other end of the negative pressure valve 8, and the gas supply line 12 is connected to the intake pipe 6. A normally open gas supply electromagnetic valve V2 (second valve) configured to supply butane gas 3 is disposed on the gas supply line 12. When the engine E starts, the negative pressure valve 8 opens in accordance with the intake negative pressure, and only butane gas 3 is supplied to the engine E via the gas supply electromagnetic valve V2. The supply of butane gas 3 can be stopped by controlling the gas supply electromagnetic valve V2, which is a normally open valve, to close. A gas nozzle 13 is connected to the end of the gas supply line 12, which is connected to the intake pipe 6, and butane gas 3 is supplied to the intake pipe 6 via the gas nozzle 13.

[0016] Next, the supply of kerosene 4, which is the main fuel for engine E, will be described. A kerosene supply line 14 and a kerosene recovery line 15 are connected to fuel tank 2. One end of kerosene supply line 14 is connected to fuel tank 2, and the other end of kerosene supply line 14 is connected to supply portion 5a of carburetor 5. A normally closed kerosene supply electromagnetic valve V3 (third valve) configured to supply kerosene 4 to supply portion 5a of carburetor 5 is disposed midway along kerosene supply line 14.

[0017] One end of the kerosene recovery line 15 is connected to the fuel tank 2, and the other end of the kerosene recovery line 15 is connected to the drain portion 5b of the carburetor 5. A normally closed kerosene recovery solenoid valve V4 (fourth valve) and a pump P are arranged along the kerosene recovery line 15, and are configured to discharge the kerosene 4 from the drain portion 5b of the carburetor 5. By providing a check valve 16 in the kerosene recovery line 15 downstream of the pump P, the flow of kerosene 4 can be stopped in the event of a malfunction of the kerosene recovery solenoid valve V4 or the pump P, and the check valve 16 functions as a so-called fail-safe.

[0018] Next, a method for starting the engine E using the starting device 100 according to the embodiment will be described with reference to FIG. 2. FIG. 2 is a control diagram of the starting device 100 of the present invention. First, the starting phase of the engine E will be described. To start the engine E, a user turns the ignition key Ig to the ON position (1), setting the ignition circuit so that the ignition mechanism I of the engine E can ignite. The ignition key Ig is a physical switch operated by the user. The engine E according to the present invention is battery-less, so power is not generated until the engine E starts rotating and a power generation unit (not shown) generates power. In other words, power is not yet supplied to an ECU (Electrical Control Unit, control device) (not shown). When starting the engine E, the throttle SV remains in the state in which the engine E was stopped (10) (described below) the previous time.

[0019] Next, the engine E is cranked (2). Cranking is performed using a recoil starter. Cranking can also be performed using a starter motor, but in this case, a known battery is provided and a signal to rotate the starter motor is output from the ECU. Cranking increases the engine speed N.

[0020] Negative pressure generated in the intake pipe 6 by cranking the engine E activates a negative pressure valve 8 via a negative pressure line 7, and butane gas 3 from a cylinder 1 is supplied to a gas supply line 12 via a regulator 9. If butane gas 3 is extracted from the cylinder 1 in liquid form, the liquid butane gas 3 is vaporized by a vaporizer 10. A gas supply electromagnetic valve V2 provided in the gas supply line 12 is a normally open valve, and supplies butane gas 3 to a gas nozzle 13 provided in the intake pipe 6.

[0021] When the engine E is cranked, a spark is generated from the ignition mechanism I, and the butane gas 3 is supplied to the engine E, which then ignites the butane gas 3 through the ignition mechanism I of the engine E, starting the engine E (3). As the engine E rotates, electricity is generated by the power generator, an engine relay Er (not shown) is turned on, and power is supplied to the ECU.

[0022] The starting device 100 does not include a choke valve. However, when starting the engine E (3), the opening S of the throttle SV of the engine E is controlled to a predetermined opening S1 so that the intake negative pressure of the engine E acts on the vacuum valve 8 to supply butane gas 3 to the engine E. By optimally controlling the opening S of the throttle SV of the engine E, the engine E can be started with butane gas 3. At this time, kerosene 4 is not supplied to the carburetor 5 of the engine E, and only butane gas 3 is supplied to the intake pipe 6 downstream of the throttle SV, starting the engine E. The predetermined opening S1 is an opening that generates an intake negative pressure that can operate the vacuum valve 8, and is an opening that supplies the butane gas 3 needed to start the engine E and ensures stable idling rotation. In reality, the opening degree S1 is about 30% of the throttle SV fully open, which is almost the same as the opening degree when the engine E is idling, but the predetermined opening degree S1 is optimally controlled depending on the temperature conditions of the engine E.

[0023] In conventional engine starting devices, the throttle SV is fully open before the engine starts, so the intake volume is throttled by a choke valve, and the fuel supplied is temporarily enriched in order to start the engine E. However, the starting device 100 according to this embodiment is characterized in that a vacuum valve 8 is operated to supply butane gas 3 to the engine E, and therefore the conventional choke valve that throttles the intake volume is eliminated. Then, the opening S of the throttle SV is adjusted to introduce the intake vacuum of the engine E to the vacuum valve 8, thereby activating the vacuum valve 8, and the engine E is started by the butane gas 3.

[0024] In Patent Document 1, which shows the prior art, LPG is supplied to a position upstream of the carburetor and downstream of the choke valve, and the distance from this supply position to the cylinder of the engine is long. On the other hand, in the starting device 100 according to this embodiment, butane gas 3 is supplied to the intake pipe 6 downstream of the throttle SV, near the engine E, so the distance from the supply position of butane gas 3 to the cylinder of the engine E is short. In other words, because the butane gas 3 supplied to the intake pipe 6 quickly reaches the cylinder, it becomes possible to easily start the engine E by adjusting the opening S of the throttle SV.

[0025] When the engine is started, butane gas 3 is supplied to the engine E, but kerosene 4 has not yet been supplied. In other words, because the normally closed kerosene supply electromagnetic valve V3 is closed, kerosene 4 is not supplied to the carburetor 5. In addition, the normally closed kerosene recovery electromagnetic valve V4 is also closed.

[0026] The temperature of engine E is measured by a temperature sensor TS mounted on the engine head. When the temperature of engine E reaches a predetermined temperature, it is determined that the first warm-up operation W1 (warm-up operation) using butane gas 3 has ended. When the first warm-up operation W1 ends, the supply of kerosene 4 begins (4). To supply kerosene 4, a normally closed kerosene supply electromagnetic valve V3 is controlled to open. Then, kerosene 4 fills the float chamber 5c of the carburetor 5, and both butane gas 3 and kerosene 4 are supplied to engine E. In other words, after the temperature of engine E reaches a predetermined temperature, kerosene 4 is supplied to the carburetor 5, and the butane gas 3 and kerosene 4 are supplied to engine E for a predetermined time.

[0027] When engine E is started, throttle SV is maintained at a predetermined opening S1 that generates a negative intake pressure that allows vacuum valve 8 of engine E to operate, and even when engine E is started with butane gas 3, throttle SV is maintained at the predetermined opening S1. And even when kerosene 4 begins to be supplied, throttle SV is maintained at the predetermined opening S1.

[0028] The period during which both butane gas 3 and kerosene 4 are supplied to engine E is defined as an overlap period (predetermined time), which is the second warm-up operation W2. During this overlap period, engine E is burning both butane gas 3 and kerosene 4, and although there may be some changes in the engine sound, the throttle SV is controlled so that the rotation speed of engine E does not fluctuate. If it is necessary to extend the overlap period, for example, when the outside air temperature is low, the overlap period can be controlled by controlling control valve V1 and gas supply electromagnetic valve V2.

[0029] To end the overlap period, normally open control valve V1 and normally open gas supply solenoid valve V2 are controlled to close. That is, after a predetermined time has elapsed, when control valve V1 and gas supply solenoid valve V2 are closed, the supply of butane gas 3 is stopped (5), only kerosene 4 is supplied to engine E, engine E enters normal operation OP, and throttle SV is controlled according to the load on engine E to an opening degree S2. In normal operation OP, when engine E is operating as an engine generator, it is possible to output electricity (100V or 200V). The start phase of engine E has been described above.

[0030] Next, the stop phase of the engine E will be described. To stop the engine E, the user turns off (6) the ignition key Ig (not shown). When the ignition key Ig is turned off, the engine E enters the stop phase, but the engine E is still rotating and has not stopped. Then, if the engine E is being operated as an engine generator, the output of electricity (100V or 200V) is stopped.

[0031] Next, the throttle SV is changed to the stop mode (7) of the engine E. Here, the opening degree S of the throttle SV is temporarily controlled to 0%. Then, the throttle SV is set to a predetermined opening degree S1. This is because the next time the engine E is started, the opening degree S of the throttle SV is set to the setting at the time of engine start.

[0032] Thereafter, the supply of kerosene 4 to the carburetor 5 is stopped (8), and the kerosene 4 in the carburetor 5 is recovered. The ECU de-energizes the kerosene supply solenoid valve V3, which closes the normally closed kerosene supply solenoid valve V3 and stops the supply of kerosene 4 to the carburetor 5. At the same time, the kerosene recovery solenoid valve V4 is energized to open it, driving the pump P to send the kerosene 4 in the float chamber 5c to the fuel tank 2, thereby recovering the kerosene 4. Note that since the engine E is still running using the remaining kerosene 4 in the float chamber 5c, electricity is supplied from the generator, and the kerosene recovery solenoid valve V4 and the pump P can be driven. The kerosene 4 in the float chamber 5c of the carburetor 5 is also recovered, but this is also an engine start-up setting to prevent kerosene 4 from being supplied to the engine E the next time the engine E is started.

[0033] The starting device 100 according to the embodiment then performs settings for restarting the engine E. That is, during the stop phase of the engine E, the throttle SV is maintained at a predetermined opening S1. Furthermore, the supply of kerosene 4 to the carburetor 5 is stopped, and the kerosene 4 in the float chamber 5c of the carburetor 5 is recovered.

[0034] Since the kerosene 4 in the float chamber 5c of the carburetor 5 is recovered, the float chamber 5c of the carburetor 5 is nearly empty the next time the engine E is started. When the engine E is restarted, even if the engine E is cranked, the kerosene 4 is not initially supplied to the engine E.

[0035] After that, the engine speed N decreases, the power generation unit stops generating power (9), the engine relay Er turns off, and the stop phase ends. In other words, since there is no power supply, the pump P stops operating and the kerosene recovery solenoid valve V4 is also de-energized. Furthermore, since there is no power, the control valve V1 and the gas supply solenoid valve V2 remain open. The ignition circuit also loses power, and the ignition mechanism I no longer ignites. After that, the rotation of the engine E stops completely (10).

[0036] According to the present invention, it is possible to provide a starting device 100 that has a simple configuration and reduces the consumption of starting fuel for an engine E that runs on fuel with a low volatile content. Furthermore, since there is no need to provide a choke valve, the number of defective products can be reduced and the configuration of the starting device 100 can be simplified.

[0037] Although butane gas 3 is used as the starting fuel, isobutane gas or propane gas can be used instead of butane gas 3. Butane gas 3 is easy to obtain but has a relatively high boiling point, so when the outside temperature is low, it is better to use isobutane gas or propane gas, which have a low boiling point. Also, kerosene 4 is supplied as the main fuel during normal operation OP, but diesel, biodiesel, or biodiesel blended fuel can be used instead of kerosene 4.

[0038] The engine E equipped with the starting device 100 according to the embodiment may be used as an engine generator. Since kerosene 4 can be used as the main fuel, the engine generator can be used even in the event of a natural disaster or emergency.

[0039] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0040] 1. Cassette gas cylinder (first tank) 2 fuel tanks (second tanks) 3 Butane gas (primary fuel) 4. Kerosene (secondary fuel) 5. Carburetor 5c Float Room 6 Intake pipe 8 Negative pressure valve (negative pressure valve) 100 Starting Device E-Engine OP Normal operation P pump SV Throttle S1 opening TS Temperature Sensor V1 Control valve (first valve) V2 Gas supply solenoid valve (second valve) V3 Kerosene supply solenoid valve (third valve) V4 Kerosene recovery solenoid valve (fourth valve) W1 First warm-up operation (warm-up operation) W2 Second warm-up operation (predetermined time)

Claims

1. A starting device for an engine that starts with a first fuel that is a gas fuel and normally operates with a second fuel, comprising: a vacuum valve configured to supply the first fuel; a carburetor configured to supply the second fuel; a throttle provided in the carburetor; a control device; When starting the engine, the control device controls the opening degree of the throttle of the engine to a predetermined opening degree so that the intake negative pressure of the engine acts on the negative pressure valve to supply the first fuel to the engine; A starting device for starting the engine, characterized in that the second fuel is not supplied to the carburetor of the engine, and only the first fuel is supplied to an intake pipe of the engine.

2. a temperature sensor for measuring the temperature of the engine; After the engine is started, only the first fuel is supplied during a warm-up operation until the temperature of the engine reaches a predetermined temperature, After the temperature of the engine reaches the predetermined temperature, the second fuel is supplied to the carburetor, and the first fuel and the second fuel are supplied to the engine for a predetermined time; 2. The starting device according to claim 1, wherein after the predetermined time has elapsed, the supply of the first fuel is cut off, only the second fuel is supplied, and the throttle is controlled in accordance with the load of the engine.

3. When the engine is stopped, the supply of the second fuel to the carburetor is stopped, and the second fuel in the float chamber of the carburetor is recovered, thereby stopping the engine; 3. The starting device according to claim 2, wherein the throttle is maintained at the predetermined opening.

4. 2. The starting device according to claim 1, wherein the first fuel is butane gas, isobutane gas, or propane gas.

5. 2. The starting device according to claim 1, wherein the second fuel is kerosene, diesel, biodiesel, or biodiesel blend fuel.

6. 4. The starting device of claim 3, wherein the float chamber of the carburetor is substantially empty when the engine is started.

7. 2. The starting system of claim 1, wherein said first fuel is supplied to an intake manifold of said engine downstream of said throttle to start said engine.

8. 2. The starting device according to claim 1, wherein the starting device does not include a choke valve for adjusting the amount of intake air of the engine.

9. a normally open first valve configured to control the suction negative pressure supplied to the negative pressure valve; a normally open second valve configured to supply the first fuel; a normally closed third valve configured to supply the second fuel to the carburetor; a normally closed fourth valve and pump configured to exhaust the second fuel from the carburetor; At the time of starting the engine, the negative pressure valve is opened via the first valve, and only the first fuel is supplied to the engine via the second valve; after the temperature of the engine reaches the predetermined temperature, the third valve is opened to supply the second fuel to the carburetor, and the first fuel and the second fuel are supplied to the engine for a predetermined time; after the predetermined time has elapsed, the first valve and the second valve are closed to cut off the supply of the first fuel, and only the second fuel is supplied to the engine; 3. The starting device according to claim 2, wherein when the engine is stopped, the third valve is closed, the fourth valve is opened, and the pump is driven to recover the second fuel in the float chamber of the carburetor, thereby stopping the engine.

10. The first fuel, The second fuel, a first tank configured to contain the first fuel; a second tank configured to contain the second fuel; A starter device; An engine comprising the starting device according to any one of claims 1 to 9, and started by the starting device.

11. An engine generator comprising a generator driven by the engine according to claim 10.

12. A method for starting an engine that starts on a first fuel that is a gas fuel and operates normally on a second fuel, comprising: when starting the engine, an opening degree of a throttle of the engine is controlled to a predetermined opening degree so that an intake negative pressure of the engine acts on a negative pressure valve configured to supply the first fuel, thereby supplying the first fuel to the engine; a starting method for starting the engine by supplying only the first fuel to an intake pipe of the engine without supplying the second fuel to a carburetor of the engine;

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