JP2011093493A - Walking type electric working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure operability and safety during a work by correcting machine body traveling speed matching the walking speed of a worker in a walking type working machine. <P>SOLUTION: This walking type working machine includes a chargeable battery and an electric motor 8 and drives a traveling part by the electric motor 8. A handle includes a pushing and pulling detection means 35 for detecting pushing and pulling of the worker. Based on the detection result of the pushing and pulling detection means 35, the number of rotation of the electric motor 8 is increased and output or lowered and output. When the pushing and pulling detection means 35 detects "pushing" of the handle by the worker, the number of rotation of the electric motor 8 is increased and output to increase the machine body traveling speed. When the pushing and pulling detection means 35 detects "pulling ", the number of rotation of the electric motor 8 is lowered and output to lower the machine body traveling speed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a walking electric work machine that includes a rechargeable battery and an electric motor, and that drives a working part or a traveling part such as a tillage part or a mowing part by the electric motor.

  Patent Document 1 discloses an arrangement configuration of a battery unit and an electric motor and an arrangement configuration of a controller. Patent Document 2 includes a controller to which an operation signal receiving unit, a control unit, a motor drive circuit, and the like are connected. The control unit receives signals from a charger, a handle mounting switch, a rotation sensor, and the like, and a display unit In addition, a display signal is issued and rotation control of the electric motor is performed via a motor drive circuit.

JP 2009-22173 A JP 2004-275100 A

  By the way, in the walking type electric working machine, the worker holds the left and right handles and performs work while correcting the direction according to the progress of the machine body. In addition, the traveling unit is driven by the rotation of the electric motor, and the traveling speed of the airframe is set based on the number of rotations of the electric motor. Therefore, depending on the walking speed of the worker, the traveling speed of the airframe is slow or the speed. However, it is a burden for the operator.

  This invention estimates the relative speed difference between the worker's walking speed and the body speed, and tries to correct the body speed to a work speed that matches the walking speed of the worker.

  In order to solve this technical problem, the present invention is a walking type electric working machine that includes a rechargeable battery B and an electric motor 8 and drives a traveling portion by the electric motor 8. A push-pull detection means 35 for detecting the push-pull is provided, and the walking type electric work machine is configured to increase or decrease the rotation speed of the electric motor 8 based on the detection result of the push-pull detection means 35. .

  With this configuration, when the push / pull detection means H detects the “push” of the handle 12 by the operator, the number of rotations of the electric motor 8 is increased and the vehicle traveling speed is increased while the “pull” is detected. Then, the rotation speed of the electric motor 8 is reduced and output, and the vehicle running speed is reduced.

  In the present invention, by providing the push / pull detection means H, it is possible to correct the traveling speed of the work machine body suitable for the worker, improving the operability and improving the safety.

Side view of electric field cultivator Rear view of electric field cultivator Top view of electric field cultivator Enlarged side view of an electric power tiller Front view inside the battery case Control block schematic diagram (A), switching circuit related block diagram (B) Block Diagram flowchart Load value-rotation increase (decrease) output relation graph Side view showing operation of safety device (A) (B) Plan views showing the operation of the safety device (A) (B) Perspective view showing another example of operation switch (A), position sensor value-motor rotational speed relationship graph (B) Enlarged view of the handle frame flowchart

An example of the walking type working machine of the present invention will be described with reference to the drawings using an electric power tiller.
Reference numeral 2 denotes a transmission frame in which a transmission shaft 41 is housed. A dish-shaped machine body frame 10 is fixed to the upper part, and the work machine frame 1 extends rearward from the transmission frame 2. A rotary shaft 3 that is rotationally driven around the horizontal axis by transmission through the transmission shaft 2a is pivotally supported at the lower part of the transmission frame 2, and a plurality of outer periphery of the rotary shaft 3 extending in the left-right direction from the transmission frame 2 is provided on the outer periphery. A rotary claw 4 is provided, and side disks 5 and 5 are attached to the left and right ends of the rotary shaft 3 to form a rotary portion R.

    A disk-shaped rotary cover 6 that covers the upper portion of the rotary part R is attached to the upper part of the body frame 10. A U-shaped wall portion 6a in a plan view is formed at the left and right central portions of the rotary cover 6, and an opening portion 6b is formed along the inside of the wall portion 6a. A motor cover 7 is attached to the front side of the opening 6b, an electric motor 8 for transmitting power to the transmission shaft 2a is housed inside the motor cover 7, and a battery B is accommodated behind the opening 6b. The battery case 9 is detachably inserted. The electric motor 8 and the battery case 9 are placed on the body frame 10 and are arranged to penetrate through the opening 6b.

  A front lower end side of a handle frame 11 is attached to a rear portion of the work machine frame 1. The handle frame 11 extends obliquely rearward and rearward. The left and right operation handles 12a and 12b are branched from the rear end side of the handle frame 11, and the grip 13a is provided at the rear ends of the left and right operation handles 12a and 12b. , 13b.

  At the rear end of the work machine frame 1, a support wheel 14 that supports the machine body when moving the electric power tiller and a resistance rod 15 that prevents dashing during the tilling work are attached. FIG. 1 shows a working posture in which the support wheel 14 is flipped up.

Next, the driving configuration of the aircraft will be described.
A key switch 16 for turning on and off the power supply is provided at a branch position between the handle frame 11 and the operation handles 12a and 12b, and an operation lever 17 for turning on and off the drive of the electric motor 8 is provided in the vicinity of the left and right grips 13b. On the rear surface of the battery case 9, an output terminal 18 of a motor drive circuit 20 that connects the battery B in the battery case 9 and the electric motor 8 and a charging terminal 19 for charging the battery B are provided.

  Here, the internal structure of the battery case 9 will be described. The battery case 9 has a rectangular parallelepiped shape and includes the output terminal 18 and the charging terminal 19 on the rear outer wall, and the front wall is configured as a detachable cover 9a. In such a battery case 9, a battery B composed of a plurality of cells 41, 41 occupying 1/2 or more of the volume of the battery case 9, and a charge control board 42 incorporating a charging circuit 42 a on the upper surface of each cell 41, 41, 42 is provided so that it can be freely inserted and removed by sliding the guide ribs 9b, 9b at the bottom in a rail shape and sliding back and forth. The terminals of the charge control board 42 are connected to the charge terminals 19 (two sets of terminals in the illustrated example) while being connected directly to the cells 41 and 41.

  A discharge control board 43 incorporating a discharge circuit 43a is provided above the charge control boards 42 and 42 disposed on substantially the same plane and spaced apart appropriately. Ribs 9c and 9c are formed on the inner peripheral side wall portion of the battery case 9 so as to form a front-rear guide recess, and the end of the discharge control base 43 is inserted into the guide recess and slid to be attached or detached. . The discharge control board 43 has a circuit configuration so that a voltage resulting from the series connection of the plurality of battery cells 41 and 41 can be output to the output terminal 18. On the inner side surface of the battery case 9, ribs 9d, 9d,... That are spaced apart from the battery cells 41, 41 and the inner wall are provided.

  The discharge board 43 is interposed in the middle of the motor drive circuit 20 that connects the battery cell 41 and the electric motor 8, and an output control circuit 43a, a current detection circuit 45, a switching circuit 46, and a current smoothing circuit are provided on the discharge board 43. 47, an overdischarge prevention circuit 48 and a short circuit prevention circuit 49 are provided.

  Among these, the output control circuit 43b receives the operation signal from the operation control circuit 51 by the key switch 16 and the operation limit switch 33, and outputs the ON / OFF switching output of the switching circuit 46. The ON / OFF switching output of the switching circuit 46 is The motor drive circuit 20 is switched to be cut off or connected.

  The current detection circuit 45 is configured to detect the control current of the discharge control board 43 and switch off the switching circuit 46 and shut off the motor drive circuit 20 when a state exceeding a preset set current value continues for a specified time. is doing.

    The charge control boards 42, 42 incorporate an overcharge prevention circuit 44, while the discharge control board 43 has a current smoothing circuit 47, an overdischarge prevention circuit 48, and a short circuit prevention circuit 49 in addition to the output control circuit 43a. Incorporated. The current smoothing circuit 47 is a circuit for smoothing a surge current generated when the operation signal is input.

    The short-circuit prevention for the discharge control board 43 can be prevented by the short-circuit prevention circuit 49. However, the short-circuit prevention for the charge control circuits 42, 42 is not provided for each of the discharge control boards 42, 42, but a common short-circuit prevention circuit. 50 is provided in the battery case 9 between the charging terminal 19 and the discharge control boards 42, 42 so as to be freely inserted into and removed from one side of the discharge control board 43 in a vertical posture.

  Next, the output terminal 18 of the battery case 9 will be described. The output terminals 18a and 18a to the electric motor 8 are two plus and minus terminals and are connected to the electric motor 8 side by the motor drive circuit 20, but the remaining two terminals 18b and 18b are signal input / output terminals. It is. That is, the pair of terminals 18b, 18b can input an ON / OFF signal from the signal control board 51 to the key switch 16 and the operation switch 33 linked to the operation lever 17 and output an operation signal to the input control circuit 43a. Based on the output from the control circuit 43a, the remaining battery level and a warning display signal to be described later are input from the signal control board 51 and output to the power on / off LED 26a, the driving warning LED 26b, and the remaining battery level LED 26c. The power on / off LED and the operation warning LED may be integrated.

  The output terminals 18 a and 18 a are connected to the electric motor 8 through a breaker 55. In other words, the breaker 55 includes an operation unit 55a for switching the motor drive circuit 20 between connection and disconnection. The operation unit 55a incorporates a solenoid (not shown), and is excited when the current value of the motor drive circuit 20 rises to operate the operation unit 55a. The motor drive circuit 20 is shut off and the electric motor 8 is turned off. The operation portion 55a of the breaker 55 is disposed on the upper surface of the rotary cover 6 in the form of an on-off switch.

    The output terminal 18 and the charging terminal 19 are respectively provided on the left and right sides of the handle frame 11 when viewed from the rear of the fuselage, and the operator does not easily get in the way of the handle frame 11 from the rear side of the fuselage on the operation side, and attaches / detaches the wiring. It is easy. In addition, since the output terminal 18 and the charging terminal 19 are arranged on both the left and right sides of the handle frame 11 in the rear view, it is possible to prevent the right and left from being inserted incorrectly.

  The motor drive circuit 20 that connects the breaker 55 and the electric motor 8 passes through the space between the lower part of the battery case 9 and the lower part of the inclined part 6 c formed on the outer periphery of the wall part 6 a of the rotary cover 6 and the body frame 10. It is configured to do.

    The battery case 9 has a handle 9e on the upper surface, a plurality of position fixing projections 9f on the lower surface, and the position fixing projections 9f are inserted into the position fixing holes 10a formed in the body frame 10. By doing so, the mounting position of the battery case 9 can be fixed. The battery case 9 is supported by the wall portion 6 a of the rotary cover 6 at the left and right side surfaces, and has a protruding portion 9 g for fixing the position that is long in the vertical direction on the front surface. It is set as the structure engaged with the recessed part 7a for use. In addition, an opening 10b is provided in the center of the left and right sides of the body frame 10 so that water that has flowed into the body frame 10 with rain water or the like can be drained.

    When the battery case 9 is set on the fuselage, the position fixing convex portion 9g is made to correspond to the position fixing concave portion 7a, and both are put in a fitted state, and the position fixing convex portion 9f is used for position fixing. The position of the battery case 9 is fixed by being inserted into the hole 10a. When the battery case 9 is taken out, it can be taken out simply by pulling up the handle 9e.

    The battery case 9 of the present embodiment is supported by the motor cover 7 on the front side and the wall portion 6a of the rotary cover 6 on the front side, but the wall portion 6a may be formed separately from the rotary cover 6. For example, it is good also as a structure formed by the wall part attached to the body frame 10 side.

    Further, by forming the wall portion 6a so as to be inclined upward, the support of the battery case 9 can be strengthened and the aesthetic appearance of the entire body can be improved. Further, a rear support wall 6d is formed on the back side of the battery case 9 to support the battery case 9 from the back side. The rear support wall 6d is formed lower than the wall 6a that supports the side surface of the battery case 9, and the output terminal 18 and the charging terminal 19 are exposed to the rear side of the fuselage so that the output terminal 18 and the charging terminal 19 are connected. It is easy to connect.

    The cover 9a of the battery case 9 is located between the motor case 7 and is formed inside the outer periphery of the main body of the battery case 9, and the outer periphery of the motor case 7 and the battery case 9 is also omitted. By forming them together, the gap is reduced and the cover 9a cannot be visually recognized from the appearance, so that the aesthetic appearance is enhanced and the intrusion of rainwater is also reduced.

    Next, the operation handles 12a and 12b are provided so as to be vertically rotatable around the horizontal axis with respect to the handle frame 11, and the handles 12a and 12b with respect to the handle frame 11 are loaded in the lifted state U or loaded in the pushed down state D. The push / pull detecting means 35 in the form of a strain gauge or a torque sensor is added or the size thereof is configured. That is, a member that can be set with a strain gauge such as a torsion bar attached to the horizontal axis is provided, and when the operator performs a tilling work while holding both or one of the handles 12a and 12b, the push / pull detecting means 35 Based on the detection, the following control is performed.

    As input signals to the control unit (operation control circuit) 51, the on / off signal of the key switch 16, the on / off signal of the operation switch 33, the lifting load or the pressing load from the push / pull detection means 35 and its load value, the electric motor 8 , The forward / reverse command signal and the rotational speed command signal of the electric motor 8 via the output control circuit 43a as a motor drive circuit. Is output.

Here, based on a flowchart, the effect | action of the said control part 51 is demonstrated.
In FIG. 8, when starting the tilling work, the key switch 16 is turned on, and the detection values of the switches and sensors are read (steps 101 and 102). Further, the set rotational speed Ms signal of the motor rotational speed setting dial is read (step 103). Next, it is detected whether or not the operation switch 33 by the operation lever 17 is ON (step 104). If the operation switch 33 is ON, the electric motor 8 is rotated and output (step 105). The rotation speed of the electric motor 8 is detected by a rotation detecting means (not shown) incorporated in the electric motor 8 at predetermined time intervals, and the detected rotation speed Ma of the motor is compared with the set rotation speed Ms. Then, it is determined whether or not the rotation speed is appropriate. If the rotation speed is not appropriate, the rotation speed is corrected to be high and low to obtain the proper rotation speed (steps 106 to 109).

    When an appropriate rotational speed is obtained in the determination of step 106, a push / pull load determination by the push / pull detection means 36 provided on the handles 12a and 12b is performed (step 110). This is when the push / pull detection means 35 detects a pushing load, that is, when the aircraft rear speed is slower than the movement speed of the operator when the operator behind the machine presses the handles 12a and 12b, The determination can be made with the load value Wn detected by the means 35. When the load value Wn is a positive value, it can be regarded as a “push” state, and when it is a negative value, it can be regarded as a “pulling” state.

    After the load value Wn is read, when the “push” is detected and determined, a rotation increase output is output to the electric motor 8, and when the “pull” is detected and determined, a rotation decrease output is output to the electric motor 8 (steps 111 to 116). ). As for the increase width or decrease width of the electric motor 8 with respect to the load value Wn, for example, by preparing a load value-rotation increase (decrease) output relationship graph as shown in FIG. 9 in advance, the increase width Ut and decrease width Dv are prepared. Can be calculated and brought close to the appropriate rotational speed at once, instead of one-step separation as in steps 107 and 108.

    Thus, by performing the process after the push / pull load determination by the push / pull detection means H, the work speed on the work machine side corresponding to the walking speed of the worker can be corrected. Since it is in the form of tillage, the rotation speed of the tillage can be adjusted up and down, so there is no unevenness in the work finish, and a uniform tillage work finish is obtained regardless of beginner or expert.

    In the load value-rotation increase (decrease) output relationship graph in FIG. 9, the response speed of step 114 or step 115, that is, the response speed is changed to a large or small depending on the magnitude of the increase width Ut or the decrease width Dv. It may be configured. If comprised in this way, it can correct to the rotation speed according to the operator's operation feeling, and can improve operativity and safety | security.

    The response speed of step 114 or step 115 may be arbitrarily set based on switch means or a dial that can be set by the operator. If comprised in this way, a response speed can be set according to an operator's skill, and it leads to the improvement of operativity and safety | security.

    The push / pull detection means 35 performs the “push” and “pull” determination by detecting the change in the angle of the handles 12a and 12b with respect to the handle frame 11 and detecting the load value by means such as a strain sensor and a torque sensor. In the case where a so-called loop handle in which the left and right handles 12a and 12b are connected to perform a work by gripping the loop handle portion, the operator's “push” “ It can be replaced by providing a detection means in the form of a pressure-sensitive sensor that can determine “pull”.

    In addition, a rotation detection sensor (cultivation shaft rotation detection means) 37 is provided at an appropriate position of the rotary shaft 3, and the rotation speed of the rotary shaft 3 is not more than a predetermined rotation speed even during the electric motor 8 rotation control by the push / pull detection means 35. By associating such that the predetermined rotation is maintained, there is little possibility that the rotation of the rotary shaft 3 becomes excessively low during the low speed control and the workability is impaired.

In the present embodiment, the configuration in which the rotary shaft 3 is single and also has a tow function is described, but the same effect can be obtained in a configuration in which the traveling unit and the tilling unit (or working unit) are driven separately.
Next, the safety device T for the operation lever 17 will be described.

  The operating lever 17 is configured to rotate around the fulcrum 30 of the horizontal axis, and is provided with a switch operating part 17 a formed on the front side of the fulcrum 30 and a gripping part 17 b formed on the rear side of the fulcrum 30. Reference numeral 33 denotes an operation switch in the form of a limit switch for inputting a signal to the control unit of the signal control board 51 in order to turn on / off the driving of the electric motor 8, and the driving of the electric motor 8 is turned on / off by the turning operation of the switch operating unit 17a. It is. Reference numeral 25 denotes a spring for returning the operating lever 17 gripped and rotated to the initial position.

    A moving shaft 31 is provided above the gripping portion 17b and supported in a direction (left-right direction) intersecting the gripping portion 17b and sliding in the left-right direction. A pushing portion 31c for pushing the moving shaft 31 toward the outside of the body is formed at the inner end of the moving shaft 31, and a spring 35 is wound around the moving shaft 31 adjacent to the pushing portion 31c. . The moving shaft 31 is formed with a small diameter portion 31a and a large diameter portion 31b adjacent to each other in order from the inside of the machine body. And it is set as the structure which the large diameter part 31b is located on the rotation locus | trajectory of the holding part 17b in the initial position of the safety device T (FIG. 11 (A)).

The operation at the time of tilling work of the operation lever 17 and the safety device T will be described below.
The state of charge of the battery B is confirmed by the presence or absence of blinking of the battery remaining amount LED 53. If the battery B is insufficient, a charger is connected to the charging terminal 19 to perform predetermined charging.

    When starting the tilling work, the key switch 16 is turned on, the pushing portion 31c formed at the end of the moving shaft 31 is pushed with the thumb, and the small diameter portion 31a is positioned on the rotation locus of the operation lever 17 (FIG. 11). (B)) Then, the operator holds the holding portion 17b and rotates to a position where the operation switch 33 is turned on. The ON signal of the operation switch 33 is transmitted to the output control circuit 43 a via the signal control board 51, the switching circuit 46 is operated to the circuit connection side, and the electric motor 8 is driven by the battery B. In response to the rotation of the electric motor 8, the rotary part R rotates and the tilling work is performed (FIG. 10B).

  When stopping the tilling work, when the operator releases the gripping part 17b, the switch operating part 17a is rotated to the initial position by the action of the spring 25, and the OFF signal of the operation signal 33 is transmitted to cut off the driving current of the battery B. Then, the rotary part R stops (FIG. 10A).

  Even when the operator carries the electric power tiller with the key switch 16 turned on, the gripping portion 17b moves even if the gripping portion 17b rotates unexpectedly by abutting against the gripping portion 17b of the operating lever 17 The operator touches the large-diameter portion 31b of the shaft 31 so that the switch operating portion 17a does not rotate to the position where the limit switch 33 is inserted, the operation switch 33 is not turned on, and the key switch 16 is turned on. Even when it is carried without being noticed, the rotary portion R will not rotate unexpectedly, so it is safe.

  Further, during a tilling operation, when the state in which the control current of the discharge control board 43 exceeds the preset current value continues for a predetermined time, this is detected by the current detection circuit 43d, and the switching circuit 43c in the ON output state is turned OFF. As a result, the motor drive circuit 20 is switched off, and the electric motor 8 is in a rotation stopped state. Therefore, the battery cell 41, the electric motor 8, and the motor drive circuit 20 can be protected by monitoring the control current for the discharge circuit 43a.

  When a load is applied to the motor drive circuit 20 and the current exceeds a predetermined value, the breaker 55 causes the motor drive circuit 20 to act on the cut-off side, and also switches the operation unit 55a to the cut side. Therefore, when starting up again, the operation unit 55a is operated to switch to ON. When the rotary part R is maintained, the operation part 55a of the breaker 55 is operated to switch the motor drive circuit 20 to the shut-off side (off), so that the non-drive of the electric motor 8 can be ensured reliably and safely. is there.

    Since the operation portion 55a is disposed on the rotary cover 6 portion (the left side of the rear portion of the rotary cover 6 in the illustrated example), the operation portion 55a is conveniently located near the maintenance work target location. That is, if the key switch 16 is disposed on the handle frame 11, it is easy for the operator who operates the handle, but it is inconvenient because it is inconvenient for the maintenance of the rotary portion R, but as described above. Constructing on the upper surface of the cover 6 is easy to reach and convenient.

    Further, although the operation switch 33 is in the form of an ON-OFF changeover switch, it is in the form of a potentiometer 33 ', and the operation angle of the operation lever 17' is transmitted to the operation angle of the potentiometer 33 '. It is good also as a structure which can set arbitrarily the maximum rotation speed (FIG. 12 (A) (B)). If comprised in this way, tillage rotation suitable for a worker's walking speed, skill, or soil quality can be performed. Moreover, starting and stopping can be performed gradually, which is safe. Note that the maximum number of rotations can be set when the operating lever 17 'is in the maximum grip state.

    The overcurrent protection circuit 45 configured on the discharge control board 43 is configured to stop the discharge output when the overcurrent of the discharge control circuit 43a is detected, and no current flows in the motor drive circuit 20. Further, the ON / OFF signal smoothing circuit 46 ensures smooth transmission by smoothing the current even when the current at startup is unstable. Further, the current smoothing circuit 47 prevents the occurrence of a surge current that may occur when the operation signal 33 is repeatedly turned ON / OFF by the operation lever 17 at the time of activation.

  Further, the overdischarge prevention circuit 48 of the discharge control board 43 suppresses and controls the voltage from the battery B to a predetermined value or lower (for example, 18 V or lower) when the voltage from the battery B is excessive. The short-circuit prevention circuit 49 relates to protection of the discharge control circuit 43a when the output terminal 18 is short-circuited, and the charge control circuit when the charge terminal 19 is short-circuited by the other short-circuit prevention circuit 50. 42a part can be protected.

  The configuration of the controller according to the present embodiment is such that the charge control boards 42 and 42 are directly connected to the battery cells 41 and 41 and accommodated in the battery case 9, and the discharge control board 43 is the charge control boards 42 and 42. Is configured to be mounted in the battery case 9 with a vertical separation, so that the connection between the charge control boards 42 and 42 and the battery cells 41 and 41 can be made directly without wire wiring, and can be made compact. On the other hand, the discharge control board 43 can be attached and detached independently from the battery cells 41 and 41 and the charge control boards 42 and 42, and the assembly property and the disassembly maintenance property are good.

    Further, the charge control circuits 42 a and 42 a of the charge control boards 42 and 42 and the charge terminal 19 are connected in parallel to perform the parallel connection process for the battery cells 41 and 41, and the output control circuit of the discharge control board 43. The battery cells 41 and 41 are output to the electric motor 8 via the output terminal 18 by serial connection with respect to 43a, and there is an effect that the parallel connection and the serial connection can be effectively assembled.

    In addition, since it is the structure which arrange | positions the charge control board | substrates 42 and 42 in the upper part of the battery cells 41 and 41 and inserts in the battery case 9, even if a water | moisture content penetrates, it accumulates below and influences board | substrates 42 and 42 itself. Less is.

Next, the configuration of the LED 26 will be described below.
A plurality of LEDs 26 indicating various operating states are provided in the vicinity of the key switch 16. That is, the key switch 16 and the LED 26 are provided on the inclined upper surface 60 a of the cover member 60 supported by the handle frame 11. The LED 26 and a holder 61 that supports the signal control board 51 to be positioned below the LED 26 are provided. The signal control board 51 receives the key switch 16 signal and the operation switch 33 signal and is connected to a pair 18 b and 18 b of the output terminal 18 by a wiring 62.

    In the present embodiment, a power on / off LED 26a, an operation on / off LED 26b, and a battery remaining amount LED 26c are provided. When the power switch is turned on and off, the key switch is turned on to emit green light of the first color, and when the overcurrent protection circuit 45 provided in the wiring 20 is detected and an overload is activated, the second color of red light is emitted. When the operation switch 33 is turned on and the rotary portion R is driven in the on / off LED 26b, the first color green is emitted, and when a protection circuit (not shown) by a temperature sensor built in the motor 8 is activated, the second color is emitted. The color red emits light. The battery remaining amount LED 26c emits green, which is the first color, when the remaining amount of the battery is normal, and emits red, which is the second color, when the remaining amount is equal to or less than the set amount. The power-on / off LED 26a may be omitted.

  In this way, various operation states are displayed with LEDs, and by appropriately changing the color from the first color to the second color, a large number of operation displays can be performed with a small number of LEDs, and in one place. It is easy to check various driving situations by placing the LEDs in a concentrated position that is easy to see from the operation side. Further, since the LED is provided adjacent to the key switch 16, it is easy to always check the LED when the power is turned on.

  The basic operation of the operation output and stop output for the electric motor 8 of the electric power tiller having the above-described configuration will be described with reference to the flowchart of FIG. When the key switch 16 is turned on (step 201), various switch signals and various detection sensor values are read (step 202). Next, it is determined whether or not the operation switch 33 is ON (step 203). When the ON signal output of both step 201 and step 203 is an operation signal, an ON signal is output to the switching circuit 46 (step 204). . When this output is received, the motor drive circuit 20 is connected, and the battery B and the electric motor 8 are in a circuit connection state and are driven to rotate (step 205).

  During operation, the current detection circuit 45 constantly monitors the control current and compares the detected current value with a predetermined value set in advance (step 206), and the breaker 55 detects the load current value of the motor drive circuit 20 and overloads. It is determined whether it is in a state (step 207). If it is less than the predetermined value in step 206 and not in an overload state in step 207, the electric motor 8 maintains the rotational drive state in order to continue the ON signal to the switching circuit 46.

  On the other hand, in the comparison with the predetermined value in step 206, when the predetermined time is not exceeded and the predetermined time is exceeded, an OFF signal is output to the switching circuit 46 as a control current abnormality (step 211), and the electric motor 8 Stops (step 212).

As described above, both the current detection circuit 45 and the breaker 55 can protect the battery B, the electric motor 8, the wiring, and the like.
In the speed increase / decrease control shown in FIG. 8, when the speed increase control is performed again after the speed reduction control, the speed is returned to the speed before the speed reduction control is performed, and the speed increase control is not performed unnecessarily. It is good to constitute so as to ensure. Also, speed detection means is incorporated in the aircraft, and the speed is monitored over time, the average speed is stored as the set speed, and the control to the speed increasing side is to increase the speed based on the average speed. By configuring, the average motor rotation speed is set to the upper limit, so that the speed is not increased unnecessarily and it is safe.

B Battery 8 Electric motor 11 Handle frame 12 Handle 35 Push / pull detection means

Claims (1)

  In a walking type working machine having a rechargeable battery (B) and an electric motor (8) and driving a traveling part by the electric motor (8), the handle (12) detects pushing / pulling of an operator. A walk-type work machine provided with a detection means (35) and configured to increase or decrease the number of rotations of the electric motor (8) based on the detection result of the push-pull detection means (35).

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