JP4434672B2 - Engine generator - Google Patents

Description

  The present invention relates to an engine generator.

  In an engine generator that generates power by being driven by the rotational output of an engine, a breaker (no-fuse breaker) is provided in the output circuit, and when many electrical loads are connected simultaneously (that is, when an overload occurs), the breaker A technique has been proposed in which the power supply is cut off by the operation of, and the engine is prevented from being damaged due to excessive output.

Further, as described in Patent Document 1, for example, an output current of the engine generator is detected, and a warning is issued to the operator before the power supply is cut off by the breaker based on the detected value. In addition, a technique for preventing the power supply from being suddenly interrupted has been proposed.
No. 7-22959 Publication

  In the above-described prior art, since the engine is prevented from being overpowered by detecting the operation of the breaker and the output current, the configuration becomes complicated and the cost is increased. There was a problem that it was difficult to apply the technology related to the generator.

  Accordingly, an object of the present invention is to eliminate the above-mentioned inconveniences, and prevent the engine from being overpowered without detecting the operation of the breaker or the output current, and thus damaging the engine while being small and inexpensive. An object of the present invention is to provide an engine generator that prevents the power supply from being suddenly cut off.

In order to solve the above-described object, according to the first aspect of the present invention, the power is generated by driving the generator with the rotational output of the engine, and the throttle is set so that the rotational speed of the engine becomes a preset target rotational speed. In an engine generator for adjusting the valve opening, a throttle opening detecting means for detecting the throttle opening, and an engine for estimating the output of the engine based on the target rotational speed and the detected throttle opening Based on the output estimation means and the estimated engine output, the target rotational speed is switched to either the first target rotational speed or the second target rotational speed set higher than the first target rotational speed. target rotation speed switching means, for when said target rotational speed is switched to the second target rotational speed, the estimated engine output for a predetermined time, the error If Jin rotational speed exceeds a predetermined value set based on the full throttle output when the second is the target rotational speed, an over output determining unit determines that the engine is over-output, and the engine is Warning means for warning the operator when it is determined that the output is excessive is provided.

  According to a second aspect of the present invention, the warning means includes at least one of a lighting means and a warning sound generating means, and the lighting means and the warning sound generating means operate the operation of the engine generator. It was configured to be placed on the operation panel.

According to the first aspect of the present invention, the engine generator generates electric power by driving the generator with the engine rotation output, and adjusts the opening of the throttle valve so that the engine rotation speed becomes a preset target rotation speed. A throttle opening detecting means for detecting the throttle opening, an engine output estimating means for estimating the output of the engine based on the target rotational speed and the detected throttle opening, and an estimated engine Based on the output, target rotational speed switching means for switching the target rotational speed to either the first target rotational speed or the second target rotational speed set higher than the first target rotational speed; when two of being switched to a target rotational speed, over the estimated engine output for a predetermined time, total engine when the engine speed is the second target rotation speed If it exceeds a predetermined value set based on the output, the engine will warn the operator when the over power determining means for determining that the excessive output, and said engine is determined to be excessive output Therefore, it is possible to prevent the engine from being overpowered with a simple configuration without detecting the operation of the breaker and the output current. In addition to preventing damage, the power supply can be prevented from being suddenly cut off.

  Especially for engine generators equipped with electronically controlled throttle devices (electronic governors), which are increasing recently, use preset target rotation speeds and detection values of existing throttle opening detection means. By doing so, it can be estimated whether or not the engine is overpowered, so that the effects of downsizing and cost reduction can be obtained more remarkably. Further, since the engine is determined to be overpowered when the estimated engine power exceeds a predetermined value over a predetermined time, the engine power is temporarily increased (accidental due to fuel accumulation or the like). Unnecessary warning can be prevented.

  According to a second aspect of the present invention, the warning means includes at least one of a lighting means and a warning sound generating means, and the lighting means and the warning sound generating means operate the operation of the engine generator. Since it is configured to be arranged on the operation panel, it is possible to more reliably transmit the warning to the operator, and more effectively prevent the engine from being overpowered.

  The best mode for carrying out an engine generator according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a front view of an engine generator according to a first embodiment of the present invention.

  In FIG. 1, the code | symbol 10 shows an engine generator. The engine generator 10 includes an engine 14 and an alternator 16 (generator) connected to the engine 14 inside a frame 12.

  An operation panel 18 is attached to the front of the engine generator 10. The operation panel 18 includes a plurality of (two) outlets 18a for taking out the output voltage of the engine generator 10, a pilot lamp 18b, an overpower warning lamp 18c, and a main switch 18d for operating the engine generator 10. With. In FIG. 1, reference numeral 20 denotes a fuel tank.

  FIG. 2 is an explanatory sectional view of the engine 14.

  The engine 14 includes one cylinder (cylinder) 22 in which a piston 24 is reciprocally accommodated. A combustion chamber 26 is formed between the head of the piston 24 and the cylinder wall surface, and an intake valve 28 and an exhaust valve 30 are disposed on the cylinder wall surface, and a space between the combustion chamber 26 and the intake passage 32 or the exhaust passage 34 is provided. Open and close. The engine 14 is specifically an air-cooled four-cycle single-cylinder OHV type internal combustion engine and has a displacement of 163 cc.

  The piston 24 is connected to the crankshaft 38, and the crankshaft 38 is connected to the camshaft 40 through a gear. A flywheel 42 is attached to one end of the crankshaft 38, and a recoil starter 44 for manually starting the engine 14 is attached to the front end side of the flywheel 42.

  The alternator 16 is connected to the other end of the crankshaft 38. The alternator 16 generates alternating current by being driven by the engine 14. The alternator 16 is a known AC generator composed of a rotor and a stator (not shown), and detailed description thereof is omitted.

  The alternating current generated by the alternator 16 is converted into direct current through a processing circuit (not shown), and then supplied as an operating power source to an ECU (not shown) or an ignition circuit (not shown), and via an inverter (not shown). After being shaped into a stable sine wave of 50 Hz or 60 Hz, it is supplied to an external device via the outlet 18a.

  A throttle body 50 is disposed upstream of the intake passage 32. A throttle valve 52 is accommodated in the throttle body 50, and the throttle valve 52 is connected to an electric motor 54 (actuator, specifically a stepping motor) via a throttle shaft and a reduction gear mechanism (both not shown). A carburetor assembly (not shown) is provided on the upstream side of the throttle valve 52 in the throttle body 50. The carburetor assembly is connected to the fuel tank 20 described above, and generates an air-fuel mixture by injecting gasoline fuel into the intake air in accordance with the opening of the throttle valve 52. The generated air-fuel mixture is sucked into the combustion chamber 26 of the cylinder 22 through the throttle valve 52, the intake passage 32 and the intake valve 28.

  A throttle opening sensor 56 is disposed near the electric motor 54 and outputs a signal corresponding to the throttle valve opening θTH (hereinafter referred to as “throttle opening”). A crank angle sensor 58 made of an electromagnetic pickup is disposed near the flywheel 42 and outputs a pulse signal at every predetermined crank angle.

  An ECU (electronic control unit) 60 is disposed in the vicinity of the engine 14. The ECU 60 includes a microcomputer and includes a CPU, a ROM, a RAM, and a counter.

  The outputs of the throttle opening sensor 56 and the crank angle sensor 58 described above are input to the ECU 60. The ECU 60 counts the output pulses of the crank angle sensor 58 and detects (calculates) the engine speed NE.

  Further, the ECU 60 calculates the energization command value for the electric motor 54 based on the detected engine speed NE and the throttle opening θTH so that the engine speed NE matches the target speed NED, and the calculated energization command. The value is output to the electric motor 54 to control its driving.

  Further, the ECU 60 lights the pilot lamp 18b indicating whether or not the engine generator 10 is normally generating power, and whether the engine 14 is overpowered based on the detected throttle opening θTH and the engine speed NE. It is judged whether or not, and when it is an overpower, the overpower warning lamp 18c is turned on. In addition, an instruction to stop the engine 14 or the like is input to the ECU 60 from the operator via the main switch 18d. The ECU 60 performs ignition cut, adjustment of the opening of the throttle valve 52, and the like according to the instruction.

  As described above, the engine generator 10 according to this embodiment drives the alternator 16 by the rotational output of the engine 14 to generate electric power, and at the same time, an electronically controlled throttle device (electronic) including the throttle body 50, the ECU 60, various sensors, and the like. The throttle valve 52 is opened and closed by a governor and the intake air amount of the engine 14 is adjusted so that the engine speed NE is controlled to the target speed NED.

  Next, of the operations of the engine generator according to this embodiment, the setting operation of the target rotational speed NED will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation. The illustrated program is executed in the ECU 60 every predetermined cycle (for example, 100 msec).

  In the following, first, in S10, the engine speed NE is detected, and the detected engine speed NE is stored in the RAM of the ECU 60. Next, in S12, it is determined whether or not the detected value of the engine speed NE is stored for a predetermined cycle (for example, 10 cycles). When the result in S12 is NO, the following process is skipped and the process is terminated. When the result is YES in S12, the process proceeds to S14, and the engine speed average value NEavg is calculated. The engine speed average value NEavg is an average value of the engine speed NE for a stored predetermined cycle (for 10 cycles).

  Next, the routine proceeds to S16, where the current value of the throttle opening .theta.TH is detected, and the routine further proceeds to S18, where the target rotational speed NED of the engine 14 is the first target rotational speed NED1 (low load target rotational speed. In this embodiment). Is set to 2000 rpm). Since the target rotational speed NED is set to the first target rotational speed NED1 when the ECU 60 is started, the description will be continued assuming that the determination here is affirmed.

  When the result in S18 is affirmative, the program proceeds to S20, and the output OP of the engine 14 is estimated. Here, the engine output OP is a value (parameter) representing the engine load, and is estimated based on the engine speed average value NEavg (generally, the engine speed NE) and the throttle opening degree θTH.

  Specifically, the engine output OP is obtained by searching a map showing the characteristics in FIG. 4 based on the average engine speed NEavg and the throttle opening θTH. As shown in FIG. 4, the characteristic of the engine output OP with respect to the throttle opening degree θTH varies according to the engine speed NE (engine speed average value NEavg). In other words, the engine output OP at that time can be estimated from the relationship between the engine speed NE (engine speed average value NEavg) and the throttle opening θTH. Therefore, in this embodiment, the relationship between the throttle opening θTH and the engine output OP is previously mapped through experiments for each rotation speed, and the detected (calculated) engine rotation speed NE (engine rotation speed average value) is mapped. NEavg) and the throttle opening θTH are searched to estimate the engine output OP.

  Returning to the description of the flowchart of FIG. 3, the process then proceeds to S22, in which it is determined whether or not the engine output OP has exceeded the first predetermined OP1, in other words, whether or not the engine load has exceeded a predetermined value. Specifically, as shown in FIG. 5, the first predetermined output OP1 is 30% output (100%) with respect to the fully open output (100%) when the engine speed NE is the first target speed NED1. Output rate 30%).

  When the result in S22 is negative (when it is determined that the engine output OP is less than the first predetermined value OP1 and the engine load is low), the subsequent processing is skipped, whereas when the result is positive in S22 (the engine output OP is the first value). (When it is determined that the engine load is large exceeding the predetermined value OP1 of 1), the process proceeds to S24, and whether or not the engine output OP exceeds the first predetermined value OP1 for the first predetermined time t1 (continuously). Judge. This determination is made by starting the counter with another program (not shown) when the result in S22 is affirmative and confirming whether or not the counter value has reached a first predetermined time t1 (for example, 1 sec). .

  When the result is negative in S24, the subsequent processing is skipped and the first target rotational speed NED1 is held, whereas when the result is positive in S24, the process proceeds to S26, and the target rotational speed NED is set as shown in FIG. It is set (changed) to a second target rotational speed NED2 (a target rotational speed at high load, which is 3000 rpm in this embodiment) that is higher than the first target rotational speed.

  If the target rotational speed NED is changed to the second target rotational speed NED2 in S26, the next program loop is denied in S18 and proceeds to S28. In S28, the engine output OP is estimated by the same method as in S20.

  After estimating the engine output OP in S28, the process then proceeds to S30, in which it is determined whether or not the engine output OP has fallen below a second predetermined value OP2, in other words, whether or not the engine load has fallen below a predetermined value. The second predetermined value OP2 is a value smaller than the first predetermined value OP1, specifically, as shown in FIG. 5, the fully open output when the engine speed NE is the second target speed NED2 ( 100%) is set to 10% output (output generation rate 10%).

  When the result in S30 is negative, the subsequent processing is skipped, while when the result in S30 is positive (when the engine output OP is below the second predetermined value OP2 and it is determined that the engine load is small), the process then proceeds to S32. Then, it is determined whether or not the engine output OP has fallen below the second predetermined value OP2 over the second predetermined time t2. This determination is made by starting the counter with another program (not shown) when the result in S30 is affirmative and confirming whether or not the counter value has reached a second predetermined time t2 (for example, 1 sec). .

  When the result in S32 is negative, the subsequent processing is skipped and the second target rotational speed NED2 is held, whereas when the result is positive in S32, the process proceeds to S34, and the target rotational speed NED is set to the above-mentioned value as shown in FIG. The first target rotational speed NED1 is set (changed).

  As described above, in this embodiment, the engine speed NE (engine speed NEavg) and the throttle opening degree θTH are detected (calculated), and the engine output OP is estimated based on these values. The target engine speed NED of the engine 14 is changed based on the engine output OP (the first target engine speed NED1 (the target engine speed at low load) and the second target engine speed NED2 set higher than that ( The engine speed NE can be changed according to the load without detecting the output current and output voltage, and is therefore small and inexpensive. However, both improvement in fuel consumption and stable power supply can be achieved.

  Further, when the estimated engine output OP exceeds the first predetermined value OP1 over the first predetermined time t1, the target rotational speed NED is set higher than the first target rotational speed NED1 at the time of low load. Since the engine speed is changed to the second target rotational speed NED2 at the time of high load, it can be accurately determined whether or not the engine 14 is at high load (temporary fluctuation of the engine output OP (such as fuel accumulation) Therefore, the target rotational speed can be changed more accurately.

  Further, when the estimated engine output OP falls below the second predetermined value OP2 set lower than the first predetermined value OP1 over the second predetermined time t2, the target rotational speed NED is set to the second value when the load is high. The target rotational speed NED2 is changed to the first target rotational speed NED1 at the time of low load, so it is possible to accurately determine whether or not the engine 14 has become a low load (temporary output of the engine output OP). Therefore, the target rotational speed can be changed more accurately. Further, it is possible to prevent the target rotational speed NE from frequently switching (control hunting occurs).

  Next, of the operations of the engine generator according to this embodiment, the overpower warning operation of the engine 14 will be described with reference to FIG. FIG. 6 is a flowchart showing the operation. The illustrated program is also executed at a predetermined cycle (for example, 100 msec) in the ECU 60.

  Before the description of the flowchart of FIG. 6 is continued, the outline of the operation will be described first. In this embodiment, the output of the engine 14 is estimated based on the target rotational speed NED of the engine 14 and the throttle opening θTH. It is determined whether or not the engine is overpowered, and when it is determined that the engine 14 is overpowered, the overpower warning lamp 18c is lit to warn the operator.

  The engine 10 overpower determination method will be described in detail. As shown in FIG. 7, from the fully open output (100%) when the engine speed NE is the second target speed NED2 (3000 rpm) at high load. An output that is lower by a predetermined rate is set as an overpower point. In this embodiment, an output of 80% of the fully open output (output generation rate 80%) is set as an overoutput point.

  FIG. 8 is a graph showing a characteristic of the throttle opening degree θTH with respect to the output occurrence rate OPrate when the engine speed NE is the second target speed NED2 (3000 rpm). By searching the graph (map) shown in FIG. 8 based on the throttle opening θTH, it is possible to estimate the output generation rate OPrate (generally, the engine output OP), and the estimated output generation rate OPrate is It can be determined whether or not the over-output point (output occurrence rate 80%) is exceeded.

  6 will be described based on the above assumption. First, in S100, it is determined whether or not the target engine speed NED of the engine 14 is the second target engine speed NED2 at the time of high load.

  When the result in S100 is negative (that is, when the first target rotational speed NED1 at the time of low load), the process proceeds to S102, and the overpower warning lamp 18c is turned off. On the other hand, when the result in S100 is affirmative, the program proceeds to S104, in which the throttle opening θTH is detected. Then, the process proceeds to S106, and the graph (map) shown in FIG. 8 is searched based on the throttle opening degree θTH, and the engine output OP, specifically, the output occurrence rate OPrate is estimated.

  Next, in S108, it is determined whether or not the estimated output occurrence rate OPrate exceeds 80%. In other words, it is determined whether or not the engine 14 is overpowered.

  When the result in S108 is negative and it is determined that the engine 14 is not overpowered, the process proceeds to S102 and the overpower warning lamp 18c is turned off. On the other hand, when the result in S108 is affirmative and it is determined that the engine 14 is overpowered, the process proceeds to S110, and whether or not the engine 14 continues to be determined to be overpowered for a third predetermined time t3 (continuously). Judge. When this determination is affirmative in S108 (when the engine 14 is determined to be overpowered), the counter is started by another program (not shown), and the count value is a third predetermined time t3 (for example, 1 sec). This is done by checking whether or not

  When the result in S110 is affirmative, the program proceeds to S112, where the overpower warning lamp 18c is turned on to warn the operator that the engine 14 is overpowered. That is, the operator is urged to reduce the electrical load on the engine generator 10.

  On the other hand, when the result in S110 is negative, the overoutput warning lamp 18c is turned off in S102. This is to prevent the engine output OP from being erroneously determined to be an excessive output of the engine 14 even if a temporary increase (accidental increase due to fuel accumulation or the like) occurs.

  As described above, in this embodiment, the engine output OP, more specifically, the output occurrence rate OPrate is estimated based on the target rotational speed NED of the engine 14 and the throttle opening θTH, and the estimated value is calculated. When the output occurrence rate OPrate exceeds a predetermined value (80%) over the third predetermined time t3, it is determined that the engine 14 is overpowered, and when the engine 14 is determined to be overpowered, an overpower warning is issued. Since the lamp 18c is lit to warn the operator, it is possible to prevent the engine 14 from being overpowered with a simple configuration without detecting the operation and output current of the breaker used conventionally. Therefore, while being small and inexpensive, it is possible to prevent the engine 14 from being damaged and to prevent the power supply from being suddenly cut off.

  In particular, in an engine generator equipped with an electronically controlled throttle device (electronic governor) as in this embodiment, a preset target rotational speed (second target rotational speed NED2) and an existing throttle By using the detection value of the opening sensor 56, it can be estimated whether or not the engine 14 is overpowered, so that the effects of downsizing and cost reduction can be obtained more remarkably.

  Further, the engine 14 is determined to be overpowered when the estimated engine output (output generation rate OPrate) exceeds a predetermined value (output generation rate 80%) for the third predetermined time t3. Further, it is possible to prevent an unnecessary warning for a temporary increase in engine output (accidental increase due to fuel accumulation or the like).

  Further, since the overpower warning lamp 18c is arranged on the operation panel 18 for operating the engine generator 10, the warning can be transmitted more reliably to the operator, so that the engine 14 It is possible to more effectively prevent over output.

  In the above description, when the engine 14 is determined to be overpowered, the overpower warning lamp 18c is turned on to visually warn, but a buzzer or the like may be sounded to warn by voice. .

As described above, in the first embodiment of the present invention, the generator (alternator 16) is driven by the rotational output of the engine (14) to generate electric power, and the rotational speed of the engine (14) is preset. In an engine generator (10) that adjusts the opening (θTH) of the throttle valve (52) so as to achieve the target rotational speed (NED), throttle opening detection means (throttle throttle) that detects the throttle opening (θTH) The opening sensor 56, S104 in the flowchart of FIG. 6, and the output (OP, more specifically, the engine (14) based on the target rotational speed (NED) and the detected throttle opening (θTH). , engine output estimation means for estimating the output power rate OPrate) (ECU 60, and S106) of FIG. 6 flowchart, the estimated based on the engine output (OPrate) The target rotational speed switching is performed to switch the target rotational speed (NED) to either the first target rotational speed (2000 rpm) or the second target rotational speed (3000 rpm) set higher than the first target rotational speed. Means (ECU 60, S18 to S34 in the flowchart of FIG. 3) and when the target rotational speed is switched to the second target rotational speed, the estimated engine output (OPrate) is maintained over a predetermined time (t3) . If the engine speed exceeds a predetermined value set based on the engine fully open output (100%) when a second target rotational speed (3000 rpm) (output power rate of 80%), the engine (14) There over power determining means for determining that the excessive output (ECU 60, S100 of FIG. 6 flowchart, S108, S110) and, and the engine (14) is configured to include a warning means for warning to the operator when it is determined that the excessive output (over power warning lamp 18c, S112 of FIG. 6 flowchart).

  The warning means includes at least one of a lighting means (18c) and a warning sound generating means (such as a buzzer), and the lighting means (18c) and the warning sound generating means are connected to the engine generator (10). It arrange | positions so that it may arrange | position to the operation panel (18) which operates the driving | operation of.

1 is a front view of an engine generator according to a first embodiment of the present invention. FIG. 2 is an explanatory sectional view of the engine shown in FIG. 1. It is a flowchart which shows the setting operation | movement of target rotational speed among operation | movement of the engine generator shown in FIG. FIG. 4 is a graph showing a characteristic of a throttle opening with respect to an engine speed average value calculated by the processing of the flowchart of FIG. 3. 3 is a graph showing the engine speed characteristic with respect to the engine output estimated by the processing of the flowchart of FIG. 3. It is a flowchart which shows the engine overpower warning operation | movement among operation | movement of the engine generator shown in FIG. FIG. 6 is a graph similar to FIG. 5 showing the characteristics of the engine speed with respect to the engine output. 6 is a graph showing the characteristics of the throttle opening with respect to the output occurrence rate estimated by the processing of the flowchart of FIG.

Explanation of symbols

10 Engine generator 14 Engine 16 Alternator (generator)
18c Overpower warning lamp (Warning means)
52 Throttle valve 56 Throttle opening sensor (throttle opening detecting means)
58 Crank angle sensor (engine speed detection means)
60 ECU (engine output estimation means, overpower determination means)

Claims (2)

In the engine generator that drives the generator with the rotational output of the engine to generate electric power and adjusts the throttle valve opening so that the engine rotational speed becomes a preset target rotational speed, the throttle opening is set to Throttle opening degree detecting means for detecting, engine output estimating means for estimating the output of the engine based on the target rotational speed and the detected throttle opening degree, and the target rotation based on the estimated engine output Target rotational speed switching means for switching the number to either the first target rotational speed or the second target rotational speed set higher than the first target rotational speed, and the target rotational speed is the second target rotational speed. when switched to the rotational speed, engine when the estimated engine output for a predetermined time, the engine rotational speed is in a second target rotational speed If it exceeds a predetermined value set based on the full-open output, warning to the operator when the engine is an over-output determining means for determining that the excessive output, and said engine is determined to be excessive output An engine generator characterized by comprising a warning means.   The warning means includes at least one of a lighting means and a warning sound generating means, and the lighting means and the warning sound generating means are arranged in the vicinity of an operation panel for operating the operation of the engine generator. The engine generator according to claim 1.

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