JP2010203246A - Engine working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine working machine improved in the restarting performance of an engine after the stopping of the engine. <P>SOLUTION: The engine working machine such as a bush cutter 1 includes a starter 19 for starting the engine 17, a battery pack 4 for supplying electric power for driving the starter 19, and a cooling fan 2 for cooling the engine 17 operated by the electric power supplied from the battery pack 4. By driving the cooling fan 2, the engine 17 in an engine case 18 and components in the vicinity thereof can be cooled by the cooling air even after the stopping of the engine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine working machine, and more particularly to an engine working machine having a cooling fan driven by a motor.

  Some engine working machines such as brush cutters and chain saws that are driven by an engine are equipped with an engine with a cell motor for starting the engine as described in Japanese Patent Application Laid-Open No. H10-228707. In such an engine working machine, the engine is housed in an engine case. During engine operation, outside air is sucked in by cooling fins formed on a magnet rotor that rotates integrally with the crankshaft, and cooling air is generated. The cooling air passes around the engine in the engine case and is discharged out of the engine case, thereby discharging heat generated in the engine from the engine case.

Japanese Utility Model Publication No. 64-11371

  By the way, when the engine is stopped, the magneto rotor is also stopped and the cooling air does not flow, and it is difficult to discharge the heat in the engine case. Then, heat is transferred to the carburetor that supplies the air-fuel mixture to the engine housed in the engine case, so that the fuel before mixing is vaporized and the air-fuel mixture concentration decreases. For this reason, when the engine is restarted in a state where the temperature of the engine is high after the engine is stopped, the startability of the engine may be deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an engine work machine that improves the restartability of the engine after the engine is stopped.

  To achieve the above object, an engine work machine according to the present invention includes a motor for starting an engine, a battery for supplying electric power for driving the motor, and the electric power supplied from the battery. And a cooling fan for cooling the engine.

  The cooling fan may be driven by the motor.

  Furthermore, the cooling fan may be driven by a cooling fan motor.

  The engine working machine further includes an engine operation state detection unit that detects an operation state of the engine, and a control unit that controls driving of the cooling fan based on an output of the engine operation state detection unit. Also good.

  Furthermore, the control means may drive the cooling fan for a predetermined time when the engine operating state detecting means detects the stop of the engine.

  The engine working machine further includes battery remaining capacity detecting means for detecting the remaining capacity of the battery, and the control means detects the remaining capacity of the battery by the battery remaining capacity detecting means during driving of the cooling fan. When it is detected that the value is equal to or less than the predetermined value, the driving of the cooling fan may be stopped.

  Further, the remaining capacity of the predetermined value is a remaining capacity of the battery capable of starting the engine, and the control means is configured to control the battery of the battery capable of starting the engine based on an output of the remaining battery capacity detecting means. It is preferable to stop driving the cooling fan while leaving a remaining capacity.

  The engine working machine may be a brush cutter.

  According to the present invention, since the engine work machine includes the engine cooling fan that operates by the electric power supplied from the battery for the motor that starts the engine, the engine and its surrounding components can be cooled after the engine is stopped. Can be improved.

1 is a perspective view of a brush cutter according to a first embodiment of the present invention. It is sectional drawing of the engine part of the brush cutter of FIG. It is a block diagram which shows the structure of the principal part of the brush cutter of FIG. It is a control circuit diagram which shows the control circuit of the brush cutter of FIG. It is a flowchart which shows control of the cooling fan of the brush cutter of FIG. It is sectional drawing of the engine part of the brush cutter which concerns on 2nd Embodiment of this invention. It is a control circuit diagram which shows the control circuit of the brush cutter of FIG. It is sectional drawing of the principal part of the brush cutter which concerns on 3rd Embodiment of this invention.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the brush cutter 1 (engine work machine) includes a hollow rod-like operation rod 14, and a rotary blade 16 is attached to one end of the operation rod 14, and an engine 17 is attached to the other end. Further, a carburetor 13 for supplying an air-fuel mixture to the engine 17 is provided at a side portion of the engine 17. As shown in FIG. 2, a rotary shaft 27 is rotatably inserted into the operation rod 14. One end of the rotary shaft 27 is connected to a bevel gear mechanism (not shown) to rotate the rotary blade 16. Further, the other end of the rotating shaft 27 is connected to a centrifugal clutch mechanism 28, and the centrifugal clutch mechanism 28 transmits the power of the engine 17 to the rotating shaft 27 when the rotational speed of the crankshaft 22 exceeds a certain level. An operation handle 15 is provided near the center of the operation rod 14 so that an operator can hold it during work. Further, between the operating handle 15 of the operating rod 14 and the engine 17, in order to operate the main switch 6 and the cell motor 19 that enable the engine 17 when it is on and stop the engine 17 when it is off. A starter switch 20, a cooling fan switch 29 that enables the cooling fan 2 to operate when turned on, and stops the cooling fan 2 when turned off, and a control circuit 5 described later are provided.

  As shown in FIG. 2, the engine 17 housed in the engine case 18 is a single-cylinder two-cycle engine having a cylinder block 12 and a crankcase 30. One end of the crankshaft 22 penetrating the crankcase 30 is connected to a recoil starter 21 for manually starting the engine, and the other end is fixed to a magnet rotor 25 having fins and connected to the magnet rotor 25. The power can be transmitted to the rotary shaft 27 via the centrifugal clutch mechanism 28.

  Further, a cell motor 19 driven by electric power supplied from the battery pack 4 (battery) is provided in the engine case 18. The pinion 24 of the cell motor 19 meshes with a reduction gear 23 slidably provided on the engine case 18, and the reduction gear 23 is connected to the magnet rotor 25 via a starting centrifugal clutch mechanism 31. When the cell motor 19 is rotated, the reduction gear 23 meshed with the pinion 24 is rotated, the crankshaft 22 is rotated and the engine 17 is started. Is released. The cell motor 19 is operated by a starter switch 20. The battery pack 4 can be removed from the brush cutter 1.

  Further, the cooling fan 2 is provided in the engine case 18. The cooling fan 2 sucks air from an air inlet 32 provided in the engine case 18, blows air toward the cylinder block 12 as indicated by an arrow in FIG. 2, circulates cooling air in the engine case 18, and 17 and components such as the vaporizer 13 are cooled. The cooling fan 2 includes a cooling fan motor 3. The cooling fan motor 3 is driven by electric power supplied from the battery pack 4, and the operation of the cooling fan motor 3 is controlled by a controller 7 built in the control circuit 5.

  As shown in FIG. 3, the controller 7 (control means) is connected to the engine operating state detection means 33, the remaining battery capacity detection means 34 (remaining battery capacity detection means), and the cooling fan 2. The engine operating state detecting means 33 detects whether the engine 17 is operating or stopped and outputs it to the controller 7. Further, the remaining battery capacity detecting means 34 detects the remaining capacity of the battery pack 4 and outputs it to the control device. The controller 7 controls the operation or stop of the cooling fan 2 based on the detection output of the engine operation state by the engine operation state detection means 33 and the output of the remaining capacity of the battery pack 4 by the battery remaining capacity detection means 34. .

  A specific control circuit 5 is shown in FIG. As shown in FIG. 4, a starter switch 20 is connected to the control circuit 5. The starter switch 20 includes a movable contact 20a, a cell motor side contact 20b, and a control circuit side contact 20c. When the starter switch 20 is pressed, the movable contact 20a comes into contact with the cell motor side contact 20b, and the cell motor 19 is operated by the electric power supplied from the battery pack 4 to start the engine 17. When the starter switch 20 is released, the movable contact 20a comes into contact with the control circuit side contact 20c to supply the power of the battery pack 4 to the control circuit 5 and to allow the charge control circuit 10 to charge the battery pack 4. .

  A main switch 6 is connected to the control circuit 5, and when it is off, the contact 6a is closed and the contact 6b is closed. The contact 6b is connected to an ignition coil (not shown). When the contact 6b is closed, the ignition coil is short-circuited and the engine 17 is stopped. When the main switch 6 is on, the contact 6b is opened, the ignition coil can be operated, and the engine 17 can be started. Whether the main switch 6 is on or off, the contact 6a is closed, and power is supplied to the control circuit 5 from the ignition coil or the battery pack 4. Further, a cooling fan switch 29 is connected to the control circuit 5. When the cooling fan switch 29 is on, the contact is closed to enable the cooling fan motor 3, and when it is off, the contact opens to disable the cooling fan motor 3.

  The controller 7 provided in the control circuit 5 includes a DC / DC converter 8 that supplies electric power, a battery voltage detection circuit 34 that detects the remaining capacity of the battery pack 4 as a voltage as a battery remaining capacity detection means 34, and a motor for cooling fan 3, a motor drive circuit 9 for driving 3, a battery remaining capacity display means 35 for displaying the remaining capacity of the battery pack 4, and an operation for detecting the operation state of the engine 17 by detecting the rotation of the output shaft of the engine 17 by a rotation sensor not shown. State detection means 33 is connected. The controller 7 is a microcomputer and incorporates a CPU, ROM, RAM, timer, A / D converter and the like (not shown). The operation state detection means 33 detects whether the engine 17 is in the operation state or the stop state by detecting the on / off state of the main switch 6 instead of the rotation sensor that detects the rotation of the output shaft of the engine 17. The state may be detected.

  Next, the control operation of the cooling fan 2 of the brush cutter 1 will be described using the flowchart of FIG. When the engine 17 is started, the engine operating state detection means 33 detects the start of the engine 17 and the controller 7 starts operation. In step 301, initial setting processing such as clearing of the timer value is performed, and then the process proceeds to step 302. In step 302, the operating state of the engine 17 is detected by the engine operating state detection means 33, and then the process proceeds to step 303. In step 303, if the engine 17 is in the operating state, the process returns to step 302. If the engine 17 changes from the operating state to the stopped state, the process proceeds to step 304.

  When the engine 17 changes from the operating state to the stopped state, in step 304, the cooling fan 2 is activated and the timer is started, and the process proceeds to step 305. In step 305, the detected value of the remaining capacity (voltage) of the battery pack 4 by the remaining battery capacity detection means 34 is stored in the memory, and the process proceeds to step 306. In step 306, it is determined whether or not the remaining capacity (voltage) of the battery pack 4 detected in step 305 is equal to or greater than a predetermined remaining capacity (voltage) sufficient to restart the engine 17 by the cell motor 19. The When the remaining capacity (voltage) of the battery pack 4 is less than the predetermined value, the process proceeds to step 308, the cooling fan 2 is stopped, and the control is finished. If it is equal to or greater than the predetermined value, the process proceeds to step 307.

  In step 307, the time after the cooling fan 2 is operated is a time sufficient for the heat in the engine case 18 to be discharged to a temperature that does not affect the mixture generation in the carburetor 13 (predetermined time T). ) Has been determined. If the predetermined time T has elapsed, the process proceeds to step 308, where the cooling fan 2 is stopped and the control is terminated. If the predetermined time T has not elapsed, the process returns to step 305. Then, the cooling fan 2 continues to operate until the remaining battery capacity becomes less than the predetermined value or until the predetermined time T elapses, and when the remaining battery capacity becomes less than the predetermined value or the predetermined time T elapses, the process proceeds to step 308 and the cooling fan 2 stops and the control ends. When it is desired to stop the cooling fan 2, the cooling fan 2 that is operating can be forcibly stopped by turning off the cooling fan switch 29.

  According to the brush cutter 1 described above, since the battery pack 4 that supplies power to the cell motor 19 supplies power to the cooling fan 2 and the control circuit 5, the cooling fan is stopped when the engine 17 is stopped even after the engine 17 is stopped. 2 can be started, and the inside of the engine case 18 can be cooled. When the remaining capacity of the battery pack 4 is sufficient, the cooling fan 2 does not raise the temperature of the vaporizer 13 and its surrounding components to a temperature that does not affect the mixture generation in the vaporizer 13. Stop after operating for sufficient time. Therefore, the startability at the time of restarting the engine 17 can be improved, and at the same time, the battery is not consumed more than necessary, so that the cell motor 19 can be fully utilized when the engine 17 is started next time. . Further, even when the remaining capacity of the battery pack 4 is not sufficient, the cooling fan 2 is stopped with a capacity that allows the engine 17 to be restarted by the cell motor 19, so that the engine 17 can still be restarted by the cell motor 19. Become. Further, when it is not necessary to restart the engine 17 such as after a day's work, the cooling fan switch 29 is turned off to stop the operating cooling fan 2 and thereby reduce battery consumption. Can do. Therefore, when the brush cutter 1 is used next time, the engine 17 can be easily started using the cell motor 19.

  Next, a second embodiment of the brush cutter according to the present invention will be described with reference to FIGS. The same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in the sectional view of the engine 17 portion of the brush cutter 101 of the present embodiment in FIG. 6, the brush cutter 101 performs both driving of the cooling fan 2 and starting of the engine 17 by a motor 119 attached to the engine case 18. Is. The drive shaft 130 of the motor 119 is connected to the cooling fan 2 together with the one-way clutch mechanism 121. The geared outer ring of the one-way clutch mechanism 121 meshes with a reduction gear 23 slidably provided on the engine case 18. When the motor 119 rotates forward, the rotation of the drive shaft 130 is transmitted from the geared outer ring of the one-way clutch mechanism 121 to the reduction gear 23 and from the reduction gear 23 to the magneto rotor 25 via the starting centrifugal clutch mechanism 31. The engine 17 is started. When the motor 119 rotates in the reverse direction, the rotation of the drive shaft 130 is not transmitted to the geared outer ring of the one-way clutch mechanism 121, but is transmitted only to the cooling fan 2, and the cooling fan 2 rotates and the arrow shown in FIG. Then, air is blown toward the cylinder block 12.

  As shown in the circuit diagram of the control circuit 105 of the brush cutter 101 of this embodiment in FIG. 7, the starter switch 120 is connected to the controller 7. When the starter switch 120 is pressed, the contact is closed and the starter drive signal is sent to the controller 7. Entered. When the starter drive signal is input to the controller 7, the controller 7 outputs a signal for rotating the motor 119 forward to the motor drive circuit 109, and rotates the motor 119 forward to start the engine 17. When the cooling fan 2 is driven after the engine 17 is stopped, the controller 7 outputs a signal for rotating the motor 119 in the reverse direction to the motor drive circuit 109 and drives the cooling fan 2 only by rotating the motor 119 in the reverse direction. The other cooling fans 2 are controlled in the same manner as in the first embodiment.

  According to the brush cutter 101 configured as described above, the same effect as that of the first embodiment is obtained, and since only one motor 119 is used to start the cooling fan 2 and the engine 17, the weight of the brush cutter 101 is reduced. This has the further advantage that the brush cutter can be made compact by reducing the mounting space.

  In the above-described embodiment, the cell motor 19 or the motor 119 directly starts the engine 17 by rotating the crankshaft 22. However, for example, a configuration including a known accumulator starter device may be used. As shown in the sectional view of only the main part in FIG. 8, in this case, the pinion 231 of the motor drive shaft 230 connected to the motor (not shown) meshes with the gear 240, and the gear 240 is rotatably attached to the engine case 18. Further, it meshes with a cooling fan drive gear 260 fixed to the drive shaft 250 of the cooling fan 2. The gear 240 is connected via a one-way clutch 270 to a known spring-type power storage device 280 composed of, for example, a coil spring, and the power storage device 280 is connected to the crankshaft 22 through a transmission mechanism 290. When the motor drive shaft 230 rotates forward, the rotation is transmitted to the gear 240, and the rotational force is stored in the power storage device 280 via the one-way clutch 270. The power storage device 280 includes a holding unit (not shown) that holds the stored rotational force up to a predetermined torque. When the torque accumulated in the energy storage device 280 exceeds a predetermined value, the holding means releases the accumulated rotational force, and the released rotational force is transmitted to the crankshaft 22 via the transmission mechanism. The engine 17 is started by rotating 22. When the motor rotates in reverse and the motor drive shaft 230 rotates in reverse, the rotation is transmitted from the gear 240 to the cooling fan drive gear 260 and the cooling fan 2 rotates. Since the one-way clutch 270 is interposed between the gear 240 and the energy storage device 280, the rotation of the gear 240 is not transmitted to the energy storage device 280.

  When the operator presses the starter switch 120, the motor rotates in the forward direction, and the rotation is transmitted to the energy storage device 280 to start storing energy. When the torque stored in the power storage device 280 exceeds a predetermined value, the stored rotational force is released, the crankshaft 22 is rotated, and the engine 17 is started. Then, after the engine 17 is stopped, the controller 7 drives only the cooling fan 2 by rotating the motor in the reverse direction. The other cooling fans 2 are controlled in the same manner as in the first embodiment. In such a configuration, the same effect as that of the first embodiment is obtained, and the motor does not directly rotate the crankshaft 22 of the engine 17, so that the torque required for the motor can be reduced. For this reason, a small and lightweight motor can be used, the capacity of the required battery can be reduced, and even if a power storage device is provided, the weight of the brush cutter can be reduced.

  The present invention is not limited to application to a brush cutter, and can be applied to various engine working machines such as a chain saw and a hedge trimmer using an engine as a power source.

DESCRIPTION OF SYMBOLS 1,101 Brush cutter 2 Cooling fan 3 Cooling fan motor 4 Battery pack 5 Control circuit 6 Main switch 7 Controller 8 DC / DC converter 12 Cylinder block 13 Vaporizer 19, 119 Cell motor

Claims (8)

A motor for starting the engine;
A battery for supplying electric power for driving the motor;
A cooling fan for cooling the engine operated by electric power supplied from the battery;
An engine working machine comprising: The cooling fan is driven by the motor;
The engine working machine according to claim 1, wherein The cooling fan is driven by a cooling fan motor.
The engine working machine according to claim 1, wherein The engine working machine is:
Engine operating state detecting means for detecting the operating state of the engine;
Control means for controlling the driving of the cooling fan based on the output of the engine operating state detecting means;
The engine working machine according to any one of claims 1 to 3, further comprising: The control means drives the cooling fan for a predetermined time when detecting the engine stop by the engine operating state detection means.
The engine working machine according to claim 4, wherein The engine working machine is:
A battery remaining capacity detecting means for detecting the remaining capacity of the battery;
The control means stops driving the cooling fan when the remaining battery capacity detecting means detects that the remaining capacity of the battery is equal to or less than a predetermined value during driving of the cooling fan.
The engine working machine according to claim 4 or 5, characterized in that. The remaining capacity of the predetermined value is a remaining capacity of the battery capable of starting the engine,
The control means leaves the remaining capacity of the battery capable of starting the engine based on the output of the remaining battery capacity detecting means, and stops driving the cooling fan.
The engine working machine according to claim 6. The engine working machine is a brush cutter;
The engine work machine according to any one of claims 1 to 7, wherein

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