JP6523983B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine such as a hydraulic shovel and a wheel loader.

  In general, a construction machine such as a hydraulic shovel includes a diesel engine as a prime mover, an alternator as a power generation device driven by the engine, and a battery charged by the alternator and serving as a power supply of various devices. At this time, on the negative side of the battery, a grounding wire connected to a vehicle body frame that is a body ground is provided. Also, it is known that a negative cut switch is provided in the middle of the grounding wire and the negative side of the battery and the vehicle body frame are electrically connected or disconnected by manually operating the switch switching member of the negative cut switch. (See, for example, Patent Documents 1 and 2).

JP, 2014-20101, A JP, 2014-88766, A

  However, in the above-described prior art, the alternator continues the power generation even when the minus cut switch is switched to the shutoff state during driving of the engine. For this reason, the electrical equipment (for example, an engine controller, an engine stop solenoid) for driving an engine is maintained by the electric power supply from an alternator.

  As a result, since the engine continues driving even when the minus cut switch is in the shutoff state, the operator may not notice that the minus cut switch is in the shutoff state. On the other hand, if the ignition key is turned off while the minus cut switch is in the shutoff state, the engine is stopped. However, even if it is attempted to start the engine again using the ignition key in this state, there is a problem that the engine does not start because power is not supplied from the battery. In addition to this, when the ignition key is turned off with the minus cut switch in the cut-off state, backup power is not supplied to the various controllers controlling the machine. For this reason, data etc. can not be written in memory, and there is a possibility that data may be damaged.

  The present invention has been made in view of the above-described problems of the prior art, and it is an object of the present invention to provide a construction machine which can stop the prime mover when the minus cut switch is switched to the shutoff state during drive of the prime mover. And

  In order to solve the problems described above, the present invention provides a vehicle body frame forming a support structure, a motor mounted on the vehicle body frame and driving a hydraulic pump, and an engine controller capable of controlling start and stop of the motor. Alternatively, an engine stop solenoid capable of controlling supply and stop of fuel to the prime mover, a power generation device mechanically connected to the prime mover and generating power by driving the prime mover, and the prime mover separately from the vehicle body frame A storage device attached and storing electric charge, and a load circuit provided on the vehicle body frame, connected to the storage device and the positive side of the power generation device, and operated by supplying power from the storage device and the power generation device; A grounding wire connecting the negative side of the power storage device to the vehicle body frame which is a body ground; Construction machine provided with a negative cut switch provided in the middle of the grounding wire and electrically connecting or disconnecting between the negative side of the power storage device and the vehicle body frame by manually operating the switch switching member An engine stop controller connected to the power storage device and capable of controlling the engine controller or the engine stop solenoid in response to the cutoff of the negative cut switch, the engine stop controller driving the prime mover When the negative cut switch is in the cut-off state, the motor is stopped by using the engine controller or the engine stop solenoid.

  According to the present invention, it is possible to stop the prime mover by the engine stop controller when the negative cut switch is shut off during driving of the prime mover.

1 is a front view showing a hydraulic shovel according to an embodiment of the present invention. It is the top view which saw the hydraulic shovel from upper direction. It is an expansion perspective view showing the state where the right rear side cover was opened. 1 is an electric circuit diagram showing an electric system of a hydraulic shovel according to a first embodiment. It is a flow chart which shows engine stop processing by an engine stop controller. It is an electrical circuit diagram showing an electrical system of a hydraulic shovel by a 2nd embodiment.

  Hereinafter, a construction machine according to an embodiment of the present invention will be described in detail with reference to the attached drawings, taking as an example a case where the construction machine is applied to a rear swing type hydraulic excavator.

  Here, FIGS. 1 to 5 show a first embodiment of the present invention. A hydraulic shovel 1 as a construction machine includes a self-propelled crawler type lower traveling body 2 having left and right crawlers (tracks) 2A, and an upper revolving structure 3 rotatably mounted on the lower traveling body 2 The swing type working device 4 is provided roughly on the front side of the upper swing body 3 via a swing post 4A. The hydraulic shovel 1 performs excavation work of soil and the like by the work device 4.

  As shown in FIG. 2, the upper swing body 3 has a width dimension in the left-right direction substantially equal to the vehicle width of the lower traveling body 2 (the distance between the left and right crawlers 2A), and a counter described later from the turning center The weight 6 is formed in a substantially circular shape as viewed from above so as to be contained within a virtual circle of a turning radius defined by the distance to the rear surface 6A of the weight 6. As a result, the hydraulic shovel 1 is a rear small turning type in which the rear surface 6A of the counterweight 6 substantially fits within the vehicle width of the lower traveling body 2 when the upper revolving body 3 performs a turning operation on the lower traveling body 2 It is configured as a hydraulic shovel.

  The swing frame 5 constitutes a vehicle body frame forming a support structure, and serves as a base of the upper swing body 3. The swing frame 5 is located on the front side and supports the swing post 4A in a swingable supporting bracket 5A, extends in the longitudinal direction an intermediate portion in the longitudinal direction, and is a partition member for partitioning between the counterweight 6 and the oil reservoir 9 It is equipped with 5B. The partition member 5B defines the device housing space 13 together with a heat exchanger 12 and a right rear side surface cover 19 described later, and suppresses transfer of heat from the heat exchanger 12 to the oil storage tank 9.

  On the other hand, on the rear end side of the swing frame 5, a counterweight 6 is disposed to balance the work device 4 in weight. Also, a cab 7 is disposed on the front left side of the turning frame 5. In the cab 7, a driver's seat 8 on which an operator is seated, various operation devices (not shown) operated by the operator, and the like are arranged.

  The oil storage tank 9 is provided on the right side of the swing frame 5. The oil storage tank 9 includes a fuel tank 9A disposed on the front right side of the swing frame 5 and a hydraulic oil tank 9B disposed adjacent to the rear side of the fuel tank 9A. The fuel tank 9A is formed as a substantially rectangular pressure-resistant tank, and stores fuel supplied to the engine 10. On the other hand, the hydraulic oil tank 9B is formed as a rectangular pressure-resistant pressure tank and stores hydraulic oil supplied to hydraulic actuators such as the work device 4 and the like.

  An engine 10 as a prime mover is provided on the front side of the counterweight 6. The engine 10 is constituted by an internal combustion engine such as a diesel engine, for example, and is disposed in a laterally extending state extending in the left-right direction. On the left side of the engine 10, a hydraulic pump 11 for supplying hydraulic pressure to the work device 4 is disposed. On the right side of the engine 10, a heat exchanger 12 composed of a radiator, an oil cooler, etc. is disposed. The engine 10 is mounted on the swing frame 5 and drives the hydraulic pump 11.

  As shown in FIG. 3, the equipment housing space 13 is formed on the right side of the heat exchanger 12 by being covered by a building cover 18. In the device housing space 13, mounted devices such as the battery 14 and the air cleaner 17 which require regular maintenance are housed. The device housing space 13 is configured to be opened or closed by the right rear side cover 19.

  The battery 14 is attached to the swing frame 5 separately from the engine 10, and constitutes a storage device for storing charge. The battery 14 is disposed on the swing frame 5 in the device housing space 13. The battery 14 supplies power to the starter 33 of the engine 10 and the like. For this reason, the positive side of the battery 14 is connected to a load circuit such as a starter 33, a display device 39, a fuel pump 43, etc., which operates by power supply from the battery 14. At this time, the load circuit is connected to the positive side (B terminal) of the alternator 32 in addition to the positive side of the battery 14. For this reason, the load circuit operates by supplying power from the battery 14 and the alternator 32. On the other hand, the negative side of the battery 14 is connected to the swing frame 5 which is the body ground by the grounding wire 15.

  The minus cut switch 16 is provided in the middle (in the middle) of the wiring path of the ground wiring 15 and includes, for example, a switch switching member 16A that is turned by the operator. The minus cut switch 16 electrically connects or disconnects between the minus side of the battery 14 and the swing frame 5 by manually operating the switch switching member 16A.

  The negative cut switch 16 is located in the device housing space 13 near the battery 14. Specifically, the minus cut switch 16 is attached to the partition member 5B, and is disposed at a position where the switch switching member 16A can be operated from the opening formed by opening the right rear side surface cover 19.

  An air cleaner 17 is provided above the battery 14 in association with the engine 10. The air cleaner 17 removes dust and the like in the outside air sucked into the engine 10 with a filter, and supplies clean intake air to the engine 10.

  The building cover 18 is provided on the swing frame 5 from the right side to the rear side of the cab 7. The building cover 18 covers the engine 10, the hydraulic pump 11, the heat exchanger 12, the oil storage tank 9, the battery 14, the air cleaner 17, and the like.

  As shown in FIG. 3, the building cover 18 includes a right rear side cover 19 that covers the device housing space 13 formed between the counterweight 6 and the oil storage tank 9 from the right side. The front end side of the right rear side cover 19 is rotatably attached to the right end portion of the partition member 5B via a hinge 20. On the other hand, on the rear end side of the right rear side cover 19, a handle portion 21 is provided. The operator can open or close the device housing space 13 by gripping the handle portion 21 and rotating the right rear side cover 19, and can perform maintenance work on the heat exchanger 12, the battery 14, the air cleaner 17, etc. It is a structure.

  Next, the configuration of the electrical system applied to the hydraulic shovel 1 will be described with reference to FIG.

  The electric system of the hydraulic shovel 1 comprises a key switch 31, a battery 14, an alternator 32, a starter 33 for starting the engine 10, a safety relay 34 for controlling the starter 33, and an operation of the lock switch 40. Safety start relay 35 for controlling safety relay 34 according to position, engine stop solenoid 36 for connecting or disconnecting the fuel supply line to engine 10, and power relay for controlling engine stop solenoid 36 37 and a timer 38. At this time, the engine stop solenoid 36 can control the supply and stop of fuel to the engine 10.

  The alternator 32 constitutes a power generation device. The alternator 32 is mounted near the engine 10 and connected by a crank pulley and a belt of the engine 10. That is, the alternator 32 is mechanically connected to the engine 10.

  The alternator 32 generates power by driving the engine 10. Specifically, the alternator 32 rotates an internal motor by the rotation of the engine 10 to generate power. A display device (monitor) 39 is connected to the L terminal of the alternator 32. When the rotational speed of the alternator 32 is slow or when the alternator 32 is stopped, the lamp of the display device 39 is lit.

  The key switch 31 is composed of a key cylinder and an engine key that can be inserted into the key cylinder, and can be turned to the OFF position, the ON position, and the START position. When the key switch 31 is operated to the OFF position, the B terminal, the C terminal and the Acc terminal are not connected to each other. Further, when the key switch 31 is operated to the ON position, the B terminal and the Acc terminal are connected to each other. When the key switch 31 is operated to the START position, the B terminal, the C terminal and the Acc terminal are connected to one another. When the key switch 31 is released after being operated to the START position, it is shifted to the ON position by the biasing force of a spring or the like.

  The B terminal of the key switch 31 is connected to the relay contacts of the battery 14 and the starter 33. That is, the motor of the starter 33 is connected to the positive side of the battery 14 through the relay contact of the starter 33. The B terminal of the key switch 31 is connected to the contact of the safety relay 34 and the B terminal of the alternator 32. That is, the contact of the safety relay 34 is connected to the battery 14, and the relay coil of the starter 33 is further connected through the contact of the safety relay 34. Further, the B terminal of the alternator 32 is connected to the battery 14. The B terminal of the key switch 31 is connected to the contact of the power relay 37. That is, the contact of the power relay 37 is connected to the battery 14, and the suction side of the engine stop solenoid 36 is further connected through the contact of the power relay 37.

  The C terminal of the key switch 31 is connected to the contact of the safety start relay 35, and is further connected to the E terminal of the safety relay 34 via the contact of the safety start relay 35. The Acc terminal of the key switch 31 is connected to the lock switch 40, and is further connected to the coil of the safety start relay 35 via the lock switch 40. The Acc terminal of the key switch 31 is connected to the C terminal of the safety relay 34, the IG terminal of the alternator 32, the holding side of the engine stop solenoid 36, and the timer 38. The Acc terminal of the key switch 31 is also connected to the fuel pump 43.

  Then, for example, when the key switch 31 is operated to the START position, the current from the battery 14 is held by the C terminal of the safety relay 34, the IG terminal of the alternator 32, and the engine stop solenoid 36 via the Acc terminal of the key switch 31. It flows to the side and the timer 38 to become the respective power supplies. In addition to this, the current from the battery 14 is supplied to the fuel pump 43 via the Acc terminal of the key switch 31 to become this power supply.

  At this time, when energized, the timer 38 excites the coil of the power relay 37 for one second, and switches the contact of the power relay 37 to the closed state. As a result, the current from the battery 14 flows to the suction side of the engine stop solenoid 36 for one second, and the engine stop solenoid 36 moves to the suction position, and the control rack (not shown) of the mechanical governor 41 (combustion injection device) Is activated. As a result, the fuel supply line from the fuel pump 43 to the engine 10 is brought into communication, and the engine 10 becomes rotatable. Note that although the contact of the power relay 37 is cut off after one second, the current from the Acc terminal of the key switch 31 flows to the holding side of the engine stop solenoid 36, so the engine 10 can rotate. It is supposed to continue.

  When the lock lever (not shown) is operated to the lock position (raised position) and the lock switch 40 is in the open contact (OFF) state, the contact of the safety start relay 35 is in the ON position, and the battery 14 A current flows to the E terminal of the safety relay 34 via the C terminal of the key switch 31 and the contact of the safety start relay 35. Thus, the safety relay 34 excites the internal coil to switch the internal contact to the closed state. Therefore, the current from the battery 14 flows to the relay coil of the starter 33 via the contact of the safety relay 34. As a result, the contacts of the starter 33 are switched to the closed state, the current from the battery 14 flows to the motor of the starter 33, and the motor rotates. As a result, the engine 10 is started.

  Then, when the engine 10 is started, the alternator 32 starts power generation, and the voltage at the P terminal and the B terminal of the alternator 32 rises. From the P terminal of the alternator 32, a pulse signal corresponding to the rotational speed of the alternator 32 is output to the H terminal of the safety relay 34. Then, when the rotation speed of the alternator 32 reaches a preset rotation speed, the rotation speed of the engine 10 is sufficiently increased to enable the continuous operation of the engine 10, so the safety relay 34 De-energize the internal coil and switch the internal contact to the open state. As a result, no current flows in the relay coil of the starter 33, the relay contact of the starter 33 is opened, and the motor of the starter 33 is stopped.

  After the engine 10 is started, the operator operates the lock lever to the unlocking position (lowering position). As a result, the lock switch 40 is in the close contact (ON) state, and the contact of the safety start relay 35 is in the OFF position. In addition to this, the supply of the hydraulic pressure from the hydraulic pump 11 to the work device 4 or the like is permitted by, for example, a lock valve (not shown), and various operations such as traveling, turning and digging of the hydraulic shovel 1 become possible.

  During operation of the engine 10, the fuel from the fuel pump 43 is supplied to the engine 10 through the governor 41. At this time, a centrifugal force corresponding to, for example, the rotational speed of the engine 10 acts on the flyweight of the governor 41. Thus, the governor 41 keeps the rotational speed of the engine 10 constant by the inertia force of the flyweight and the governor spring force.

  The governor 41 variably controls the injection amount (fuel injection amount) of the fuel injected into the cylinder (not shown) of the engine 10 according to the operation position of the fuel lever 42. As a result, the rotational speed (rotational speed) of the engine 10 is controlled to be the target rotational speed set by the fuel lever 42.

  Thereafter, for example, when the key switch 31 is operated to the OFF position, the power to each circuit is turned off. The current flowing from the Acc terminal of the key switch 31 to the holding side of the engine stop solenoid 36 disappears, and the engine stop solenoid 36 moves to the stop position by the biasing force of the spring. As a result, the fuel supply line to the engine 10 is shut off, and the engine 10 is stopped.

  The engine stop controller 44 is connected to the battery 14. Specifically, the engine stop controller 44 is directly connected to the positive side and the negative side of the battery 14. For this reason, the engine stop controller 44 can be supplied with power from the battery 14 in any state of connection and disconnection of the negative cut switch 16 and can continue operation.

  The engine stop controller 44 is connected to the ground side of the negative cut switch 16 and the negative side of the battery 14, and the negative cut switch 16 is turned off (ON) based on, for example, the current value and resistance value therebetween. It can be monitored which of the states (OFF). Further, an input terminal of the engine stop controller 44 is connected to an Acc terminal of the key switch 31.

  Further, the engine stop controller 44 includes a switch 45 provided in the middle of the power supply wiring to the engine stop solenoid 36 and the fuel pump 43. The switch 45 is controlled by the engine stop controller 44 in the connection state and the disconnection state. The switch 45 may be incorporated, for example, in the engine stop controller 44, and is provided at a position different from the engine stop controller 44, and is switched between the connection state and the disconnection state based on the control signal from the engine stop controller 44. It may be something. The switch 45 is normally connected to permit the supply of power to the engine stop solenoid 36 and the fuel pump 43.

  Further, an output device of the engine stop controller 44 is connected to a notification device 46 including, for example, a buzzer and a lamp. The notification device 46 may be provided inside the cab 7 in order to give notification to the operator who got on the cab 7, and is provided outside the cab 7 in consideration of the notification to the surroundings of the hydraulic shovel 1 May be

  The engine stop controller 44 can control the engine stop solenoid 36 in response to the cutoff of the negative cut switch 16. That is, the engine stop controller 44 executes a program for engine stop processing shown in FIG. 5 and controls the switch 45 and the notification device 46 in accordance with the state of the minus cut switch 16. Specifically, the engine stop controller 44 supplies a voltage from the alternator 32 when the negative cut switch 16 is in the cut off state and the Acc terminal of the key switch 31 supplies the power supply voltage (for example, +12 V) from the battery 14. Therefore, it is determined that the engine 10 is in operation. At this time, the engine stop controller 44 uses the notification device 46 to notify the operator or that the engine 10 is stopped around. When the predetermined time which has been determined in advance after the notification is opened, the engine stop controller 44 switches the switch 45 to the cutoff state. As a result, the power supply to the engine stop solenoid 36 and the fuel pump 43 is stopped, so the fuel supply to the engine 10 is stopped and the engine 10 is stopped.

  Next, a program for engine stop processing by the engine stop controller 44 will be described with reference to FIG. The engine stop process is repeatedly performed at a predetermined constant cycle.

  For example, when the vehicle is activated by an ignition key or the like, a program for engine stop processing is activated. In step 1, it is determined whether the Acc terminal of the key switch 31 is in the power ON state. Specifically, it is determined whether current is supplied from the battery 14 or the alternator 32 to the Acc terminal of the key switch 31.

  When the determination in step 1 is "NO", since the engine 10 is stopped, the alternator 32 is in a non-power generation state. Therefore, the engine stop controller 44 does nothing and ends the program as it is.

  On the other hand, when "YES" is determined in step 1, there is a possibility that the alternator 32 is generating electric power by the rotational drive of the engine 10. For this reason, the process proceeds to step 2 to determine whether the minus cut switch 16 is in the cutoff state (OFF).

  When the determination in step 2 is “NO”, the negative cut switch 16 is in the connected state (ON), so step 1 and subsequent steps are repeated. On the other hand, when the determination in step 2 is “YES”, since the minus cut switch 16 is switched to the cutoff state during driving of the engine 10, the processes of step 3 and subsequent steps are executed to stop the engine 10.

  In step 3, the engine stop counter is used to count down a predetermined time until the engine stop. In step 4, the notification device 46 is operated to notify the operator and the surroundings that the engine 10 is to be stopped. In step 5, data is stored in various controllers that control, for example, an air conditioner, a radio, a lighting apparatus, and the like. Specifically, each controller is caused to execute a process for stopping operation and a process for writing necessary data into the non-volatile memory. In the following step 6, based on the time measured by the counter, it is determined whether or not a predetermined time determined in advance has passed after the determination in step 2 is “YES”.

  At this time, the predetermined time is set to, for example, a value of about one minute until the work device 4 or the like is changed to a stable posture until the engine 10 stops. The fixed time is appropriately set in consideration of the time required for the posture change of the work device 4 and the like.

  If it is determined in step 6 that the result is "NO", step 3 and subsequent steps are repeated because a predetermined time has not elapsed. On the other hand, when “YES” is determined in the step 6, a predetermined time has elapsed since the negative cut switch 16 is in the cutoff state. Therefore, the engine stop controller 44 switches the switch 45 to the shutoff state. As a result, the power supply to the engine stop solenoid 36 and the fuel pump 43 is stopped, and the engine stop solenoid 36 is turned off. As a result, since the control rack of the governor 41 moves to the stop position by the spring, the fuel supply to the engine 10 is stopped, and the engine 10 is stopped.

  At this time, steps 3 and 6 in FIG. 5 show a specific example of the off timer which waits until a predetermined time passes before stopping the engine 10. When the negative cut switch 16 is switched to the shutoff state while the engine 10 is stopped, processing similar to that in step 5 may be performed to write data of each controller in the non-volatile memory.

  Thus, according to the present embodiment, the engine stop controller 44 connected to the battery 14 and capable of controlling the engine stop solenoid 36 in response to the cutoff of the minus cut switch 16 is provided. Here, in the small hydraulic excavator 1, the minus cut switch 16 is disposed in the device housing space 13 for performing maintenance work such as the heat exchanger 12, the battery 14, the air cleaner 17, and the like. Therefore, when the maintenance work is performed in a state where the engine 10 is driven, there is a possibility that the minus cut switch 16 is switched to the cutoff state. At this time, since the alternator 32 continues the power generation by the driving of the engine 10, the engine stop solenoid 36 maintains the operating state, and the hydraulic shovel 1 can operate normally. Therefore, the operator may not notice that the minus cut switch 16 is in the shutoff state.

  On the other hand, in the present embodiment, the engine stop controller 44 uses the engine stop solenoid 36 to stop the engine 10 when the minus cut switch 16 is in the shutoff state while the engine 10 is being driven. Therefore, the operator can know that the negative cut switch 16 has been switched to the shut off state by stopping the engine 10, and can switch the negative cut switch 16 to the connected state before starting the engine 10 next time. .

  Further, since the engine stop controller 44 is provided with an off timer that waits until a predetermined time elapses before stopping the engine 10, the operator changes the posture of the hydraulic shovel 1 to a stable state before the engine 10 stops. be able to. For this reason, it can suppress that the hydraulic shovel 1 stops by an unstable attitude | position by stop of the engine 10. FIG. In addition to this, since various controllers secure a certain time until the power supply is stopped, the data writing to the internal memory can be completed during that time, and the data damage can be suppressed.

  Furthermore, the engine stop controller 44 further includes a notification device 46 operated by the engine stop controller 44, and the engine stop controller 44 operates the notification device 46 when the engine 10 is stopped. For this reason, the notification device 46 can notify in advance that the engine 10 is stopped, to an operator, a worker located around the hydraulic shovel 1, and the like. As a result, before the engine 10 stops, the operator can, for example, change the posture of the working device 4 in a stable state, and the surrounding workers know in advance that the hydraulic shovel 1 stops. Can.

  Next, FIG. 6 shows an electric system of a hydraulic shovel according to a second embodiment of the present invention. A feature of the present embodiment is that the engine stop controller stops the engine using the engine controller. In the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The electric system according to the second embodiment includes a key switch 51, a battery 14, an alternator 32, a starter 33, a starter relay 52, and a safety start relay 53.

  At this time, the starter 33 is connected to the positive side of the battery 14. That is, the contact of the starter relay 52 is connected to the positive side of the battery 14, and the relay coil of the starter 33 is connected via the contact of the starter relay 52.

  The Acc terminal of the key switch 51 is connected to the display device 39. Therefore, when the key switch 51 is in the ON position or the START position, the display device 39 is supplied with power via the Acc terminal of the key switch 51 and starts up.

  The C terminal of the key switch 51 is connected to one end of the coil of the starter relay 52 and the engine controller 55 (ECU). The Acc terminal of the key switch 51 is connected to the IG terminal of the alternator 32, the fuel pump 43 and the engine controller 55. In addition to this, the Acc terminal of the key switch 51 is connected to the lock switch 40 and is further connected to the coil of the safety start relay 53 via the lock switch 40.

  Then, for example, when the key switch 51 is operated to the START position, the current from the battery 14 is supplied to the IG terminal of the alternator 32, the fuel pump 43 and the engine controller 55 via the Acc terminal of the key switch 31. Power supply. Further, the current from the Acc terminal of the key switch 51 flows to the safety start relay 53 and the lock switch 40. At this time, the engine controller 55 operates a control rack (not shown) of the electronic governor 54 (combustion injection device). As a result, the fuel supply line from the fuel pump 43 to the engine 10 is brought into communication, and the engine 10 becomes rotatable. Therefore, the engine controller 55 can control the start and stop of the engine 10.

  When the lock lever (not shown) is operated to the lock position (raised position) and the lock switch 40 is in the open contact (OFF) state, the contact of the safety start relay 53 is in the ON position and the battery 14 The current flows to the engine controller 55 via the safety start relay 53. In addition to this, the current from the C terminal of the key switch 51 flows to the engine controller 55.

  When current flows from both the key switch Acc terminal and the C terminal, the engine controller 55 connects the other end of the coil of the starter relay 52 to the ground, and excites the starter relay 52. As a result, the contacts of the starter relay 52 are connected, the current from the battery 14 flows to the motor of the starter 33, and the motor rotates. As a result, the engine 10 is started.

  On the other hand, when the lock lever is operated to the lock release position (lower position) and the lock switch 40 is in the close contact (ON) state, the contact of the safety start relay 53 is in the OFF position. As a result, no current from the safety start relay 53 is supplied to the engine controller 55, so the engine controller 55 stops the excitation of the starter relay 52. As a result, in the state where the lock lever is lowered, even if the key switch 51 is at the START position, the starter 33 does not rotate and the engine 10 does not start.

  Then, when the engine 10 is started, the alternator 32 starts power generation, and the voltage at the P terminal and the B terminal of the alternator 32 rises. At this time, the engine controller 55 detects the rotational speed of the engine 10 by a signal from a rotation sensor (not shown). When the rotational speed of the engine 10 reaches a preset rotational speed, the engine controller 55 deactivates the coil in the starter relay 52 to switch the internal contact to the open state. As a result, no current flows in the relay coil of the starter 33, the relay contact of the starter 33 is opened, and the motor of the starter 33 is stopped.

  The engine controller 55 may determine whether or not the engine 10 has reached a preset rotational speed based on the output voltage from the P terminal of the alternator 32 as well as the signal from the rotation sensor. .

  After the engine 10 is started, the operator operates the lock lever to the unlocking position (lowering position). As a result, the lock switch 40 is in the close contact (ON) state, and the contact of the safety start relay 53 is in the OFF position. In addition to this, the supply of the hydraulic pressure from the hydraulic pump 11 to the work device 4 or the like is permitted by, for example, a lock valve (not shown), and various operations such as traveling, turning and digging of the hydraulic shovel 1 become possible.

  During operation of the engine 10, fuel from the fuel pump 43 is supplied to the engine 10 through the governor 54. At this time, the governor 54 calculates the difference between the target rack position and the actual rack position (the actual position of the control rack), and controls the rack position by the actuator. Thus, the governor 54 keeps the rotational speed of the engine 10 constant.

  Further, a rotation sensor or the like that detects the rotational speed of the engine 10 is connected to the engine controller 55. The engine controller 55 outputs a control signal to the governor 54 in accordance with the rotational speed of the engine 10. At this time, the governor 54 variably controls the injection amount (fuel injection amount) of the fuel injected into the cylinder (not shown) of the engine 10 based on the control signal output from the engine controller 55. Thereby, the number of revolutions (rotational speed) of the engine 10 is controlled to be the number of revolutions corresponding to the target number of revolutions by the control signal from the engine controller 55.

  Thereafter, for example, when the key switch 51 is operated to the OFF position, the power to each circuit is turned off. At this time, the current flowing from the Acc terminal of the key switch 51 to the engine controller 55 disappears. As a result, since the control signal to the governor 54 is not output from the engine controller 55, the control rack of the governor 54 moves to the stop position. In addition to this, since the power supply to the fuel pump 43 is lost, the fuel pump 43 is also stopped. As a result, the fuel supply line from the fuel pump 43 to the engine 10 is cut off, and the engine 10 is stopped.

  The engine stop controller 56 is directly connected to the positive side and the negative side of the battery 14. The engine stop controller 56 is connected to the ground side of the minus cut switch 16 and the minus side of the battery 14, and monitors whether the minus cut switch 16 is in the connected state (ON) or in the disconnected state (OFF). can do. Further, an input terminal of the engine stop controller 56 is connected to an Acc terminal of the key switch 51.

  Further, the engine stop controller 56 is provided with a switch 57 provided in the middle of the power supply wiring to the engine controller 55 and the fuel pump 43. The switch 57 is controlled by the engine stop controller 56 in the connection state and the disconnection state. The switch 57 may be incorporated in, for example, the engine stop controller 56, and may be provided at a position different from the engine stop controller 56. The switch 57 is normally connected, and permits the supply of power to the engine controller 55 and the fuel pump 43.

  Further, an output device of the engine stop controller 56 is connected to a notification device 46 including, for example, a buzzer and a lamp. The engine stop controller 56 executes a program for engine stop processing shown in FIG. 5 and controls the switch 57 and the notification device 46 in accordance with the state of the minus cut switch 16. Specifically, when the engine cut controller 56 is supplied with the power supply voltage from the battery 14 from the Acc terminal of the key switch 31 when the negative cut switch 16 is in the cut off state, the voltage is supplied from the alternator 32, It is determined that the engine 10 is in operation. At this time, the engine stop controller 56 uses the notification device 46 to notify the operator or that the engine 10 is stopped around. The engine stop controller 56 switches the switch 57 to the shutoff state when a predetermined time that has been determined in advance has passed since the start of the notification. As a result, the power supply to the engine controller 55 and the fuel pump 43 is stopped, so the fuel supply to the engine 10 is stopped, and the engine 10 is stopped.

  The electrical system according to the second embodiment has the configuration as described above. In the second embodiment configured as described above, the engine stop controller 56 causes the engine controller 55 to stop the engine 10 when the minus cut switch 16 is in the shutoff state while the engine 10 is being driven. . For this reason, also in the second embodiment, the same operation and effect as those of the first embodiment described above can be obtained.

  In addition, in embodiment mentioned above, the crawler type hydraulic shovel 1 was illustrated as a construction machine. However, the present invention is not limited to this, and may be applied to, for example, a wheel-type hydraulic shovel, and can be widely applied to other construction machines such as a hydraulic crane.

1 Hydraulic excavator (construction machine)
2 lower traveling body 3 upper swing body 4 working device 5 swing frame (body frame)
10 engine (motor)
11 Hydraulic pump 14 Battery (power storage device)
15 Wiring for grounding 16 Minus cut switch 16A Switch switching member 31, 51 Key switch 32 Alternator 33 Starter (load circuit)
36 Engine stop solenoid 39 Display device (load circuit)
41, 54 Governor (fuel injection device)
43 Fuel pump (load circuit)
55 engine controller 44, 56 engine stop controller 45, 57 switch 46 notification device

Claims (3)

A body frame forming a support structure;
A motor mounted on the body frame and driving a hydraulic pump;
An engine controller capable of controlling start and stop of the motor, or an engine stop solenoid capable of controlling supply and stop of fuel to the motor;
A power generation device mechanically connected to the motor and generating power by driving the motor;
A power storage device attached to the vehicle body frame separately from the motor and storing charges;
A load circuit provided on the vehicle body frame, connected to the power storage device and the positive side of the power generation device, and operated by supplying power from the power storage device and the power generation device;
A grounding wire connecting the negative side of the power storage device to the vehicle body frame which is a body ground;
A construction machine provided with a negative cut switch provided in the middle of the grounding wire and electrically connecting or disconnecting between the negative side of the power storage device and the vehicle body frame by manually operating a switch switching member In
It further comprises an engine stop controller connected to the storage device and capable of controlling the engine controller or the engine stop solenoid in response to the cutoff of the negative cut switch.
The engine stop controller is configured to stop the prime mover using the engine controller or the engine stop solenoid when the minus cut switch is shut off during driving of the prime mover. machine.   The construction machine according to claim 1, wherein the engine stop controller is provided with an off timer which waits until a predetermined time elapses before stopping the prime mover. The system further comprises a notification device operated by the engine stop controller,
The construction machine according to claim 1, wherein the engine stop controller operates the notification device when stopping the prime mover.

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