JP2010084673A - Engine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable engine tool that is environment friendly by improving fuel economy and improved in operability compared with a conventional portable engine tool. <P>SOLUTION: This engine tool has a throttle motor for rotating a throttle valve of a carburetor for controlling the rotational speed of an engine and a cell motor for starting the engine mounted thereon, and is capable of switching between the rotational speed appropriate for work of the engine and the stopped state of the engine according to the operation of an on/off switch. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine tool having an engine as a power source.

In portable engine tools, in order to control the rotational speed of the engine, which is the power source, the amount of inflow air and wind speed are changed by the opening of the throttle valve of the carburetor, and the rotational speed is controlled by changing the amount of inflow of fuel. is doing. In general, the operator can obtain the opening degree of the valve according to the pulling amount of the throttle lever by operating the throttle lever connected to the throttle valve, and the amount of inflow air with the throttle lever pulled most If the throttle lever is not pulled and the throttle lever is not pulled, the engine is fully closed with the minimum amount of inflow air left, and the engine speed is low when the work is stopped (the so-called idling state). ).

6-67841

  In this way, the engine is in a low-speed idling state when the operation is paused. However, even in this idling state, the engine speed is maintained so that the engine does not stop, so that noise and vibration are generated and fuel is consumed little by little.

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the above-mentioned drawbacks of the prior art and to prevent unnecessary fuel consumption and improve fuel consumption by stopping the engine during work suspension. It is to provide environmentally friendly engine tools. Further, it is to provide a lower noise engine tool by stopping the engine during the operation stop. Another object is to improve the operability by allowing the engine to be started and stopped and to control the number of revolutions suitable for work with a single switch.

  Of the inventions disclosed in the present application, typical features will be described as follows.

  According to one aspect of the present invention, in an engine tool including an engine and a starting device for starting the engine, an on / off switch for controlling driving of the engine is provided, and the on / off switch is in an ON state. The engine speed increases to the working area, and the engine stops when the on / off switch is in the OFF state.

  According to another feature of the present invention, a cell motor may be further provided, and the cell motor may be rotated to start the engine when the on / off switch is turned on while the engine is in a stopped state.

  According to another feature of the present invention, when the on / off switch is in an OFF state, the select switch can select a stop mode for stopping the engine and an idling mode for maintaining the engine speed at a low speed. Can be further provided.

  According to another aspect of the present invention, a throttle motor that controls a rotational speed by operating a throttle opening of a carburetor of the engine, a drive unit that drives the throttle motor, and a rotation that sets the rotational speed of the engine Number setting means and control means for outputting a drive signal to the drive means for the throttle motor in accordance with the output of the rotation speed setting means can be further provided.

  According to another feature of the present invention, the control means controls the throttle motor so that the engine has a rotational speed set by the rotational speed setting means when the on / off switch is in an ON state. it can.

  According to another feature of the present invention, a battery pack for supplying electric power to the cell motor and the control means can be further provided.

  According to another feature of the present invention, the battery pack further comprises a battery remaining amount detecting means for detecting the remaining capacity of the battery pack, and the on / off switch is turned off when the remaining capacity of the battery pack becomes a predetermined value or less. Even when the engine is in a state, the engine can be maintained at a low rotation speed without stopping the engine.

  According to another feature of the present invention, the battery pack further comprises: a power supply circuit that uses the generated energy of the ignition coil as a power source of the control means; and battery connection detection means for detecting whether or not the battery pack is connected. If not connected, the engine can be maintained at a low speed without stopping the engine even when the on / off switch is turned off.

  According to another feature of the invention, the drive power of the control means can be provided by the output of an ignition coil connected to the engine.

  According to the first aspect of the present invention, an on / off switch for controlling the driving of the engine is provided, and when the on / off switch is in the ON state, the engine speed increases to a work area and the on / off switch is turned off. Since the engine is configured to stop when it is in a state, it is possible to stop the engine when the work is stopped, and it is possible to provide an engine tool that is low in fuel consumption and friendly to the environment without consuming unnecessary fuel. In addition, since the engine is stopped when the operation is stopped, it is possible to supply a lower noise engine tool.

  According to a second aspect of the present invention, a cell motor is further provided, and when the on / off switch is turned on while the engine is in a stopped state, the cell motor is rotated to start the engine. Thus, the engine can be restarted directly, so that even if the engine is stopped during non-working, the work can be easily restarted and comfortable work can be performed.

  According to a third aspect of the present invention, there is provided a select switch capable of selecting a stop mode for stopping the engine and an idling mode for maintaining the engine speed at a low speed when the on / off switch is in the OFF state. Further, since the operator can arbitrarily select a conventional idling mode and a stop mode excellent in environmental performance, the tool can be used in accordance with the working state.

  According to the invention of claim 4, the throttle motor for controlling the rotational speed by operating the throttle opening of the carburetor of the engine, the drive means for driving the throttle motor, and the rotational speed setting means for setting the rotational speed of the engine And a control means for outputting a drive signal to the throttle motor drive means in accordance with the output of the rotation speed setting means, so that the throttle opening can be operated by the motor and stable at a constant speed. Work can be performed.

  According to a fifth aspect of the present invention, the control means controls the throttle motor so that the engine has a rotational speed set by the rotational speed setting means when the on / off switch is in an ON state. As a result, there is no need for the operator to adjust the pulling amount of the on / off switch, and the engine can be started and stopped and the number of revolutions suitable for the work can be controlled with a single switch, thereby improving the operability.

  According to the sixth aspect of the present invention, it is possible to drive the cell motor even when the engine is not in a driving state by further including a battery pack for supplying electric power to the cell motor and the control means.

  According to a seventh aspect of the present invention, the battery pack further comprises battery remaining amount detecting means for detecting the remaining capacity of the battery pack, and the on / off switch is turned off when the remaining capacity of the battery pack becomes a predetermined value or less. When the battery pack becomes low, the engine is not stopped and the engine speed is maintained at a low speed, so that when the remaining capacity of the battery pack is low, battery consumption can be minimized. .

  According to an eighth aspect of the present invention, the battery pack further includes a power supply circuit that uses the generated energy of the ignition coil as a power source of the control unit, and a battery connection detection unit that detects whether or not the battery pack is connected. If not, the battery pack is not connected because the engine is not stopped and the engine speed is maintained at a low speed even when the on / off switch is turned off. Sometimes, it becomes possible to ensure the workability as before.

  According to the ninth aspect of the present invention, the driving power of the control means is given by the output of the ignition coil connected to the engine, so that the power generation energy of the ignition coil can be used together as the power source of the control circuit. The control circuit can be driven even when the pack has a small capacity or is not connected.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

  FIG. 1 is a circuit diagram according to the first embodiment of the present invention, and FIG. 2 is an overall schematic diagram of a tool according to the first embodiment of the present invention. Here, a case where the present invention is applied to a brush cutter is shown as an example. The brush cutter 23 has an engine 20 and is configured to perform work by transmitting a driving force to the working unit 22 via the operation rod 21. Near the center of the operation rod 21, an operator handle 19 is provided for an operator to hold the brush cutter 23 during work, and an on / off switch 5 for operating the rotational speed of the engine 20 is arranged on the operator handle 19. Has been.

  The brush cutter 23 in the present embodiment includes a control circuit 2 to be described later that is driven by power from the battery pack 1 disposed near the lower portion of the engine 20, so that the operation brush is less affected by the heat of the engine 20. 21 is disposed near the mounting portion of the operation handle 19. The control circuit 2 controls switches such as the main switch 3, the on / off switch 5, the select switch 6, and the rotation speed setting circuit 8, and various switches are also provided near the control circuit. When the main switch 3 is OFF, the contact 3a is opened to cut off the power supply to the control circuit 2, and the contact 3b is closed. The contact 3b is connected to an ignition coil (not shown). When the contact 3b is closed, the ignition coil (not shown) is short-circuited and the engine 20 is stopped. When ON, the contact 3b is opened and the engine 20 can be started. At the same time, the contact 3a is closed and the voltage of the battery pack 1 is supplied to the DC / DC converter 4 that outputs 5V, and the control circuit 2 starts its operation. While the ON / OFF switch 5 is in the ON state, the engine speed is controlled to a speed suitable for work according to the output of a speed setting circuit described later. The select switch 6 can select two modes of idling and stop for the state of the engine 20 when the on / off switch 5 is in the OFF state. The rotation speed setting circuit 8 includes a variable resistor 8a, a resistor 8b, a capacitor 8c, and the like, and can set the rotation speed stepwise. The operation of the control circuit 2 is controlled by the microcomputer 7 and includes a CPU, ROM, RAM, timer, A / D converter, etc. (not shown).

  The engine 20 has a manual starter (not shown) and a cell motor 9 as a starting device. The cell motor 9 can start the engine 20 by rotating a crankshaft of the engine 20 (not shown) via a gear and a power storage device (not shown).

  Further, the brush cutter 23 includes a throttle motor 11, which is driven forward and backward by the output signal of the microcomputer 7 via the drive circuit 12, holds the throttle of a carburetor (not shown) in a predetermined position, and controls the rotational speed of the engine 20. . In the present embodiment, a stepping motor that can easily switch between forward and reverse rotation, can be controlled without a rotation angle detection circuit, and has a large torque at rest is used.

  The control circuit 2 includes a relay 13, a battery voltage detection circuit 14, and a battery remaining amount display circuit 15, and the relay 13 can stop the engine 20 by short-circuiting an ignition coil (not shown) by a signal from the microcomputer 7. I can do it. The battery voltage detection circuit 14 estimates the remaining battery capacity from the battery voltage, and the battery remaining capacity display circuit 15 turns off the LED when the battery voltage is higher than a predetermined value, and turns on the LED when the battery voltage is lower than the predetermined value. Inform the user that the remaining battery capacity is low. Since the battery remaining amount display circuit 15 is disposed on the operation handle 19, the operator can always check the remaining battery amount while holding the brush cutter 23.

Next, the operation will be described with reference to the flowchart of FIG. When the main switch 3 is turned on, the contact 3a is closed and the voltage of the battery pack 1 is supplied to the control circuit 2, whereby the microcomputer 7 starts to operate. Step 301 is an initial setting process, and an initial process such as port input / output setting is performed.
In step 302, the voltage from the rotation speed setting means 8 is A / D converted and read as a rotation speed command value. In step 303, the state of the on / off switch 5 is confirmed. In step 304, the state of the select switch 6 is confirmed, and each state is stored as a latest state determination value in a memory (not shown) in the microcomputer 7, and the previous state determination value is stored in the memory. Stored in another area as the previous state determination value.

  In step 305, the battery voltage is detected via the battery voltage detection circuit 14, and when the battery voltage is lower than a predetermined first predetermined value, it is determined that the remaining battery capacity is low. The LED 15 is turned on to notify the user that the remaining battery capacity is low, and in step 308, the state determination value of the select switch 6 previously read in step 304 is rewritten to the idling mode regardless of the actual state. . If the state determination value of the on / off switch 5 previously read in step 309 is not different from the previous state determination value, the process returns to step 302, and if it is different from the previous state determination value, that is, if the on / off switch 5 is operated, step Proceed to 310.

If the state determination value of the on / off switch 5 is on in step 310, the process proceeds to step 311 to check the state determination value of the select switch 6. If the state determination value of the select switch 6 is in the idling mode, the process proceeds to step 313 and a drive signal is output to the throttle motor drive circuit 12 in accordance with the value of the rotational speed command value to drive the throttle motor 11 and the rotational speed of the engine is the rotational speed. Control is performed so that the predetermined value set by the setting means 8 is obtained. If the state determination value of the select switch 6 is the stop mode in step 311, the process proceeds to step 312, the cell motor 9 is driven via the drive circuit 10, the engine is started, and the speed setting means 8 is set in step 313. The engine is controlled to the predetermined number of revolutions, and the process returns to step 302.
In step 310, when the state determination value of the on / off switch 5 is OFF, the process proceeds to step 314, and the state determination value of the select switch 6 is confirmed. If the state determination value of the select switch 6 is the idling mode, the process proceeds to step 315 to drive the throttle motor 11 via the drive circuit 12 to set the engine to the idling state and return to step 302. If the state determination value of the select switch 6 is the stop mode, the process proceeds to step 316, the relay 13 is driven, an ignition coil (not shown) is short-circuited to stop the engine 20, and then the process returns to step 302. The relay 13 returns to the open state after stopping the engine 20. At this time, the engine 20 may be stopped after a predetermined time elapses after the state determination value of the on / off switch 5 is turned off.

In the above embodiment, the operation is described using the battery pack 1 as a power source. However, as shown in FIG. 4, the output voltage of an ignition coil (not shown) is stabilized by a stabilization circuit (not shown), and is supplied to the control circuit 2 via a diode 17. Power may be supplied. In this case, it is also possible to charge the battery pack 1 via the charge control circuit 18. When the battery pack 1 is not set, the control circuit 2 can start operation only after the output voltage of the ignition coil is stabilized after the engine is started, so that the cell motor 9 cannot be driven when the engine is started. Therefore, the engine is started manually. Since the control circuit 2 operates after the engine is started, it is possible to drive the throttle motor 11 and switch the rotational speed. However, when the select switch 6 is in the stop mode, if the engine 20 is stopped every time the on / off switch 5 is turned off, the manual engine start becomes complicated and the work efficiency is lowered. 14 is smaller than the second predetermined value which is smaller than the first predetermined value, it is determined that the battery pack 1 is not connected, and the engine speed is set during the operation stop regardless of the state of the select switch 6. The idling state does not impair the operability. Further, when the voltage of the battery pack 1 is larger than the second predetermined value and smaller than the first predetermined value, it is determined that the remaining capacity of the battery is low, and the LED of the battery remaining amount display means 15 is turned on to leave the remaining battery capacity low. In addition to notifying the user of the fact that the battery pack 1 is idle regardless of the state of the select switch 6, the engine speed is set to an idling state to suppress the consumption of the battery pack 1, and the battery pack 1 is connected via the charging control circuit 18. When the battery voltage is recovered by charging the battery, idling or stopping can be performed when the operation is suspended depending on the state of the select switch 6. (Disclosed flowchart)
Further, the configuration is such that the rotational speed of the engine 20 is detected from the pulsed output of the ignition coil, and the rotational speed of the engine 20 is fed back to the control circuit to keep the rotational speed constant even if the load of the engine 20 changes. If so, the operability is further improved.

  As mentioned above, although demonstrated based on embodiment which shows this invention, this invention is not limited to the above-mentioned form, A various change is possible within the range which does not deviate from the meaning. For example, in the embodiment of the present invention, the on / off switch 5 is configured to control the engine to the predetermined rotation speed set by the rotation speed setting means 8, but the ON state of the on / off switch is divided stepwise to the pull amount. By controlling the throttle motor 11 so as to achieve a corresponding set rotational speed, it is possible to perform control to a constant engine rotational speed while eliminating the need for fine adjustment of the pulling amount, thereby improving workability.

The select switch 6 sets the operation pattern in the OFF state, but the OFF state is configured to have an idling state and a stop state, and the idling state is maintained even when the select switch 6 releases the on / off switch 5. It may be configured to include a locking unit that can only be used, and to allow the on / off switch to be stopped when the locking unit is removed.

1 is a circuit diagram showing a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The tool whole schematic which shows 1st embodiment of this invention. The flowchart which shows 1st embodiment of the control method of this invention. The circuit diagram which shows 2nd embodiment of this invention.

Explanation of symbols

  1 is a battery pack, 3 is a main switch, 4 is a DC / DC converter, 5 is an on / off switch, 6 is a select switch, 7 is a microcomputer, 9 is a cell motor, 11 is a throttle motor, 13 is a relay, 14 is a battery voltage detection circuit It is.

Claims (9)

Engine,
In an engine tool comprising a starting device for starting the engine,
An on / off switch for controlling the driving of the engine is provided, and when the on / off switch is in the ON state, the engine speed increases to a work area, and when the on / off switch is in the OFF state, the engine Engine tool characterized by stopping.   The engine tool according to claim 1, further comprising a cell motor, wherein the cell motor rotates when the on / off switch is turned on in a state where the engine is in a stopped state, and the engine is started.   The apparatus further comprises a select switch capable of selecting a stop mode for stopping the engine when the on / off switch is in an OFF state and an idling mode for maintaining the engine speed at a low rotation state. The engine tool according to any one of claims 1 to 2.   A throttle motor for controlling the rotational speed by operating a throttle opening of the carburetor of the engine, a driving means for driving the throttle motor, a rotational speed setting means for setting the rotational speed of the engine, and the rotational speed setting means The engine tool according to any one of claims 1 to 3, further comprising a control unit that outputs a drive signal to the drive unit of the throttle motor in accordance with the output of the motor.   5. The control unit according to claim 1, wherein the control unit controls the throttle motor so that the engine has a rotation speed set by the rotation speed setting unit when the on / off switch is in an ON state. The engine tool according to any one of the above.   The engine tool according to claim 4, further comprising a battery pack for supplying electric power to the cell motor and the control means.   The battery pack further comprises a battery remaining amount detecting means for detecting the remaining capacity of the battery pack, and when the remaining capacity of the battery pack becomes a predetermined value or less, the engine is activated even when the on / off switch is turned off. The engine tool according to claim 6, wherein the engine speed is maintained at a low speed without stopping.   A power supply circuit that uses the generated energy of the ignition coil as a power source for the control means; and battery connection detection means for detecting whether or not the battery pack is connected, and when the battery pack is not connected, the on / off switch The engine tool according to claim 6 or 7, wherein the engine speed is maintained at a low speed without stopping the engine even when is turned off. The engine tool according to any one of claims 4 to 8, wherein a driving power source of the control means is provided by an output of an ignition coil connected to the engine.

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