JP4249888B2 - Control device for work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a work vehicle that can improve maintainability such as failure diagnosis when a failure occurs due to an excessive current due to a short circuit of a circuit load.
[0002]
[Prior art]
In recent work vehicles, in order to realize high performance, high function, high maintainability, and the like, many control devices that control actuators based on electric signals are used. These control devices are mainly composed of computers, perform predetermined calculation processing based on detection signals of various sensors, output a control command according to the calculation results, and drive each working machine, vehicle running, etc. There are provided various electric or hydraulic actuators to be controlled and a driving device for driving the various actuators in response to the control command. Usually, when various sensors or actuators fail, wiring shorts to these devices, ground faults, etc. occur, protection is provided so that excessive current does not flow to the controller, each driving device, each actuator and wiring. Therefore, each circuit is provided with an overcurrent protection function and a protection device such as a current limiting circuit and a fuse. In the case of a construction machine, as a fuse, a normal fuse that melts and protects a circuit when an excessive current flows is mounted at a predetermined place in a replaceable manner.
[0003]
In the unlikely event that a part of the circuit load is faulty and short-circuited and an overcurrent flows, the fuse of the circuit is blown to protect the circuit. In such a case, a field engineer (so-called serviceman) investigates the cause of the failure, replaces it with a new new fuse, and starts up the control device again.
[0004]
[Problems to be solved by the invention]
However, the following problems occur in the conventional circuit protection method using the fuse as described above. In the unlikely event that a fuse blows, the normal procedure is to replace the fuse with a new one after the field engineer has investigated the cause of the failure. However, in recent control devices, many loads (actuator drive circuits, sensors, etc.) are often connected to a single control device in order to achieve high functionality, high performance, and high maintainability. In addition, load paths of devices and the like are complex and diverse. Therefore, it is difficult to investigate the cause of the failure immediately in a short time. Conversely, in order to investigate the cause of the failure, the fuse is temporarily replaced, the control device is turned on again, and the failure status is grasped. A lot is done. For this reason, until the true cause is finally investigated, the power is turned on many times and a plurality of fuses are blown. As a result, a large number of spare fuses are required, resulting in an increase in maintenance cost, and if there is no spare fuse at the time of failure repair, it is very difficult to investigate the cause of the failure.
[0005]
In particular, in the case of a vehicle failure at a site far from the service center where the field engineer is located, such as a quarry in the back of the mountain, it takes time for the field engineer to go back and forth between the site and the service center. For this reason, it is required to complete the failure repair with only one field work as much as possible. For this reason, it is necessary to grasp the failure status in detail, estimate the cause of the failure, prepare repair parts thoroughly, and go to the site. The symptoms of the vehicle when the power is turned on several times to workers at the site You may also need to be contacted. At this time, the fuse may blow several times when the power is turned on again. Conventionally, there are many spare fuses on site or in the vehicle, so it is difficult to grasp the failure status in detail. As a result, there are problems that the number of round-trips between field engineers increases and that it takes time to repair the failure.
[0006]
The present invention has been made paying attention to the above-mentioned problems. When an overcurrent abnormality occurs in an electric circuit of a control device, the work vehicle can be turned on again and the cause can be easily investigated. It aims to provide a control device.
[0007]
[Means, actions and effects for solving the problems]
In order to achieve the above object, a first invention of a work vehicle control device according to the present invention includes an electric circuit that controls a work actuator and a drive actuator for traveling or the like and is provided with a protection device against overcurrent. In the control apparatus for a work vehicle, the protective device includes a circuit breaker, and the circuit breaker is provided at a predetermined position of a vehicle body. The circuit breaker includes a monitor device and an engine controller to which a plurality of current loads are respectively connected. And a power supply circuit to the pump controller .
[0008]
According to the first invention, even when the circuit breaker is turned off (tripped) due to an overcurrent of the load, the power can be turned on again immediately after being turned on many times. Therefore, it becomes easier to grasp the failure state and facilitate the failure diagnosis. It becomes like this. In addition, if a certain function is not used (for example, if a certain actuator is not driven), the circuit breaker may not be tripped and the vehicle can be moved and moved. At this time, the circuit breaker may be turned on again for the time being. Since it can move to a place close to the service center, it becomes easier to repair. In addition, since circuit breakers are provided at predetermined locations, the circuit breakers are easy to operate and maintainability is very good.
[0009]
In addition, when a circuit breaker of a control device to which a large number of current loads are connected, such as a monitor device, an engine controller, and a pump controller, trips, in order to investigate which of a plurality of current loads causes a short circuit, You can grasp the failure status by turning on the power several times. Therefore, it becomes very easy to repair the failure of these devices. Since it is not necessary to prepare a large number of spare fuses as in the prior art, it is economical.
[0010]
According to a second aspect of the present invention, based on the first aspect, the circuit breaker is provided in the vicinity of the power supply battery on the vehicle body .
[0011]
According to the second invention, the distance between the circuit breaker and the power source battery is shortened, and the number of circuit parts protected by the circuit breaker can be increased. Therefore, the reliability and maintainability of the electric circuit can be improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. In the following embodiments, a hydraulic excavator will be described as an example of a work vehicle. FIG. 1 is a side view of a hydraulic excavator to which the present invention is applied. The hydraulic excavator shown in FIG. 1 includes a lower traveling body 1 that is driven to travel by a traveling motor that is controlled by receiving pressure oil from a hydraulic pump that is rotated by the power of an engine (not shown). An upper swing body 2 is rotatably mounted at a substantially central portion of the lower traveling body 1 and is driven to rotate by a swing motor (not shown). Further, a work machine 3 such as a boom, an arm, and a bucket is attached to the upper center of the swivel frame 2a of the upper swing body 2 so as to be swingable up and down, and each work machine hydraulic cylinder (the boom cylinder 3a). Etc.). A driver's cab 4 is mounted on the front left end of the swivel frame 2a, and a battery 7 is mounted on the right front of the swivel frame 2a. A first step cover 5 is provided above the battery 7 so as to be openable and closable, and covers the top of the battery 7. The first step cover 5 may be freely opened and closed by rotating in the front-rear direction or the left-right direction. In addition, a second step cover 6 is attached to the rear of the first step cover 5 so as to be inclined rearward and upward, and an inner plate 9 covered with the second step cover 6 has a circuit breaker box. 10 (hereinafter referred to as CB box) is attached. In the CB box 10, as will be described in detail later, a predetermined number of circuit breakers (hereinafter referred to as CB) for protecting the power supply circuit of the control device are provided. A handrail 5b is provided at a side end portion of the upper surface of the step covers 5 and 6.
[0013]
FIG. 2 is a perspective view of the CB box 10 and the battery 7 mounting portion. As shown in FIG. 2, a footrest plate 5 a is fixed to the upper surface portion (above the battery 7) of the first step cover 5. In addition, a hole 6a is formed in the second step cover 6 in front of the CB box 10, and a step plate 8 is attached to the second step cover 6 so as to be openable and closable so as to cover the hole 6a. The step plate 8 is formed with a recess provided with a step 8a.
[0014]
FIG. 3 is a circuit block diagram of a control apparatus having an electric circuit using CB according to the present invention. In the following, for simplification of description and easy understanding, description will be made functionally (functionally) with a focus on the connection of the power supply circuit. In the figure, the output voltage of the battery 7 is input to the B terminal of the starter switch 31 via the CB11 in the CB box 10, and is applied to the excitation coil 32c of the battery relay 32 from the BR terminal when the starter switch 31 is turned on. . The excitation current of the battery relay 32 returns to the negative voltage terminal (usually vehicle body ground) of the battery 7. When the battery relay 32 is turned on, the power source current from the battery 7 passes through the CB 12, 13, 14, 15, 16, and 17 in the CB box 10 from the output a contact 32 a (normally open) of the battery relay 32. 33 (for the window of the cab 4), a work machine lamp 34 (illuminates the front of the work machine 3), a headlight 35 (vehicle headlamp), an electric grease pump 36, a pump controller 37 (work machine 3 and vehicle) The hydraulic pump for the hydraulic actuator that drives the traveling is controlled), and is supplied to predetermined fuses 21, 22, 23, etc. in the fuse box 20. From these fuses 21, 22, 23, etc., power is supplied to an air conditioner, a heater, a horn 68, a radio, a window washer motor, and the like.
[0015]
The output voltage of the battery 7 directly passes through the CB 18, 19, 17a in the CB box 10 respectively, and the engine controller 38 (controls the engine speed efficiently and with high accuracy) and the monitor device 39 (man-machine). Interface), and is applied to predetermined fuses 25, 26, etc. in the fuse box 20, and the fuses 25, 26, etc. supply power to room lights, step lights (for step covers 5 and 6). Are supplied respectively.
[0016]
The current load of the pump controller 37 includes a travel solenoid valve 41 and a swing solenoid valve 42 that respectively control the drive of the travel motor 45 and the swing motor 46, and the travel motor 45, the swing motor 46, and the working machine hydraulic cylinder 49 (the boom). The cutoff cancel solenoid valve 43 and the torque control electromagnetic for efficiently and accurately controlling the output torque of the variable displacement hydraulic pump 47 that supplies pressure oil via the control valve 48 that can be controlled to the control cylinder 3a, etc. The solenoid valve 41, 42, 43, 44 is controlled by a control command current from the pump controller 37. The pump controller 37 also has detection signals from various sensors 51 such as pressure sensors and pressure switches, a switch signal from an actuator control interlock switch 52, and a detection signal from an engine air cleaner clogging sensor 64. Etc. are input respectively.
[0017]
The current load of the engine controller 38 (controls the engine speed efficiently and with high precision) includes an injector 61 (engine fuel injection valve), a supply pump 62 (pressure-feeding fuel), an engine speed, Sensors 63 such as various pressures, oil temperatures, and water temperatures are connected. The injector 61 and the supply pump 62 are controlled by a control command current from the engine controller 38. The starter motor 65 is supplied with a power supply current directly from the C terminal of the starter switch 31 when the starter switch 31 is turned on.
[0018]
Further, as a current load of the monitor device 39, a wiper motor 33, a horn 68, a buzzer 67 (used for running alarm alarm, work machine alarm alarm, etc.) and the like are connected. It operates by the control command current.
[0019]
Each of the CBs 11 to 17a and 19 is set with a cutoff characteristic between a current value (rated current value) at the time of trip and an operating time according to the maximum load current in the corresponding circuit. These CBs have a trip switch that returns when an overcurrent flows and trips (that is, jumps outward from the CB body). After tripping, the power can be turned on again by pressing this trip switch. These CBs are suitable for use environment conditions such as vibration, impact and ambient temperature when the work vehicle is operated. In addition, since a return trip switch is used, it can be downsized and is suitable for in-vehicle use.
[0020]
According to the above configuration, since the power supply circuit of each control device, drive device and electrical equipment of the control device is overcurrent protected by the CB, an overcurrent occurs due to a short circuit failure of any load. However, it is possible to safely protect each device, and it is possible to immediately turn on the power again for failure diagnosis. At this time, it is not necessary to prepare a large number of spare fuses as described in the section of the prior art, and the power can be turned on any number of times. Therefore, failure diagnosis can be easily performed, and it is very economical. In particular, a circuit corresponding to a control device such as a pump controller 37, an engine controller 38, and a monitor device 39, in which a large number of current loads such as actuators and sensors are connected to each other in order to improve the control function and increase the accuracy. Even if an overcurrent abnormality occurs, it is possible to immediately check the failure status after turning on the corresponding CB and turning on the power again while sequentially disconnecting the current load connected to the control device. The cause can be easily investigated in a short time.
[0021]
In addition, since the CB box 10 is disposed in the vicinity of the power supply battery 7 and the wiring distance between the CB box 10 and the battery 7 is shortened, the range of circuit parts (devices and wiring) that can be protected by the CB can be widened and reliable. Increases sex. Moreover, since the CB box 10 is installed at a place where it is easy to open and close from the outside and the CB is easy to operate, workability at the time of repair is good.
[0022]
Further, for example, a short circuit between the motor coil and the case inside the electric grease pump 36 occurs, and the electric grease pump 36 is operated so that the short circuit current flows only when the internal electric motor is at a predetermined rotational position. If such a failure occurs, the CB 15 is turned on again, the power is turned on again, and the work vehicle can be moved to a predetermined service point without operating the electric grease pump 36. This makes it possible to repair the failure more easily.
[0023]
The position where the CB box 10 is installed is not limited to the above position, and may be any place where other workers can easily access. For example, FIGS. 4-6 has shown the other Example of the position which installs the CB box 10, and provides a space between the cab 4 and the hydraulic oil tank 71 installed in the back of the cab 4, and this. The CB box 10 may be installed in the space. In the CB box 10, it is arranged so that it is easy to push the trip switch after each CB trips, and in front of the CB box 10 in this operating direction (that is, the side of the CB box 10 in FIG. 5). A maintenance cover 72 that can be freely opened and closed is provided. By installing the CB box 10 immediately behind the cab 4 in this way, the operator's access from the cab 4 becomes very good, so the workability at the time of failure diagnosis is good.
[0024]
It should be noted that the CB may be applied only to a device whose cause is difficult to determine when performing failure diagnosis and the power needs to be turned on multiple times, and a fuse may be applied to other devices. The CB is not limited to the one having a return trip switch, but may be a circuit breaker.
[0025]
According to the present invention, since the power supply circuit of the work vehicle is provided with CB, when a short-circuit failure occurs, the failure symptom can be grasped immediately after the power is turned on again as many times as necessary. And it becomes possible to investigate the cause of failure accurately in a short time, and the maintainability can be improved.
[Brief description of the drawings]
FIG. 1 is a side view of a hydraulic excavator to which the present invention is applied.
FIG. 2 is a perspective view of a CB box and battery mounting portion according to the present invention.
FIG. 3 is a circuit block diagram of a control device having an electric circuit using the CB of the present invention.
FIG. 4 is a side view showing another embodiment of the installation position of the CB box.
FIG. 5 is a plan view of FIG. 4;
FIG. 6 is an explanatory diagram of a CB box.
[Explanation of symbols]
2 ... upper revolving structure, 2a ... swivel frame, 3 ... working machine, 4 ... cab, 5, 6 ... step cover, 7 ... battery, 8 ... step plate 8a ... step, 10 ... CB box, 11-19 ... CB, 20 ... fuse box, 31 ... starter switch, 32 ... battery relay, 33 ... wiper motor, 34 ... Work machine light, 35 ... Headlight, 36 ... Electric grease pump, 37 ... Pump controller, 38 ... Engine controller, 39 ... Monitor device, 41 ... Electromagnetic traveling Valve, 42 ... Swivel solenoid valve, 43 ... Cutoff cancel solenoid valve, 44 ... Torque control solenoid valve, 45 ... Travel motor, 46 ... Swivel motor, 47 ... Variable displacement type Hydraulic pump, 48 ... switching valve, 49 ... hydraulic cylinder for work equipment, 51 ... sensor, 52 ... interlock switch, 61 ... injector, 62 ... sup Iponpu.

Claims (2)

In the control device for the work vehicle, which controls the work machine (3) and the drive actuator (49, 46, 45) for traveling, etc., and has an electric circuit provided with a protection device against overcurrent,
The protective device has a circuit breaker (11-19),
The circuit breaker (11-19) is concentrated on a predetermined part of the vehicle body ,
The circuit breakers (11 to 19) are respectively provided in power supply circuits to a monitor device (39) , an engine controller (38) and a pump controller (37) to which a plurality of current loads are respectively connected .
A control device for a work vehicle. 2. The work vehicle control device according to claim 1, wherein the circuit breaker (11-19) is provided in the vicinity of a power supply battery (7) on a vehicle body .

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