JPH0539197A - Interlock device for work machine - Google Patents

Abstract

PURPOSE:To form a device by providing an oil hydraulic pump driven by an electric motor and an oil hydraulic pump driven by an engine, for driving a hydraulic actuator, so that the hydraulic actuator is driven by any of the oil hydraulic pump but can not be driven simultaneously by both the oil hydraulic pumps. CONSTITUTION:The case of driving an electric motor 10 is detected by the first detecting means R2, and the case driven by an engine is detected by the second detecting means R3 and also restricting an engine starting means 27 by the first restricting means R2b, when the first detecting means R2 is actuated, and an electric motor starting means 23 by the second restricting means R3a when the second detecting means R3 is actuated, so that a hydraulic actuator can not be driven simultaneously by both oil hydraulic pumps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working machine in which a boom is erected and swung freely by a hydraulic actuator appropriately arranged on a vehicle, and in particular, it is driven by a hydraulic pump driven by an electric motor and an engine. The present invention relates to a working machine which is provided with a hydraulic pump described above, and selectively drives these hydraulic pumps to drive the hydraulic actuator.

[0002]

2. Description of the Related Art An aerial work vehicle A shown in FIG. 3 will be described below as an example of this type of work machine. The aerial work vehicle A has a swivel base 2 rotatably mounted on a vehicle 1 and a boom 3 having a base end portion pivotally supported and erected freely. The boom 3 is composed of a telescopic boom 4 in which a plurality of booms are telescopically inserted in a telescopic manner (hereinafter, the boom 3 will be described as a telescopic boom 4 in which a plurality of booms are telescopically inserted in a telescopic manner). At the tip of 4 is provided a bucket 5 on which the operator can ride so as to freely rotate (hereinafter, referred to as swinging).

In this aerial work vehicle A, the swivel base 2 is swung with respect to the vehicle 1 by means of a hydraulic motor 6 for swiveling, which is appropriately arranged between the vehicle 1 and the swivel base 2. A hoisting hydraulic cylinder 7 is arranged between the telescopic boom 4 and the swivel base 2 so that the telescopic boom 4 can be hoisted and driven with respect to the swivel base 2. The telescopic boom 4 in which a plurality of booms are inserted in a telescopic manner is arranged such that a telescopic hydraulic cylinder 8 is arranged between the booms on the base end side and an appropriate wire rope or the like is provided between the other booms (not shown). ) Is placed,
The telescopic boom 4 can be driven to extend and retract. Between the tip of the telescopic boom 4 and the bucket 5, a hydraulic motor 9 is appropriately arranged so that the bucket 5 can be swung with respect to the tip of the telescopic boom 4.

Such an aerial work vehicle A, which has been used for work in a cargo hold or indoors in recent years, and which is driven by the power of an engine in a closed work place, requires exhaust gas countermeasures. Therefore, it has become necessary to drive the electric motor. Therefore, both power sources of the electric motor 10 and the engine 11 are provided on the swivel base 2 of the aerial work vehicle A, and the hydraulic pump 1 is used as the power source of the electric motor 10.
2 to drive the hydraulic pump 13 with the engine 11 power source.
Can be driven. The hydraulic pumps 12 and 13 are selectively used to drive the hydraulic actuator.

The hydraulic actuators and hydraulic pumps 12, 13 arranged on the work vehicle A in this way are
It is controlled by a hydraulic circuit as shown in FIG. That is, the hydraulic power source from the hydraulic pump 12 or the hydraulic pump 13 is drive-controlled by operating the respective control valves 14, 15, 16, 17 arranged corresponding to the hydraulic actuators. The hydraulic pumps 12, 13 and respective control valves 14, 15, 16, 17
A relief valve 18 is arranged between them to regulate the maximum pressure of the hydraulic circuit.

[0006]

However, the aerial work vehicle A constructed as described above is inadvertently operated by the electric motor 10.
And both power sources of the engine 11 were sometimes operated. In this case, the speed of each actuator is increased by receiving the discharge amount from both hydraulic pumps 11 and 12, or the set pressure cannot be controlled by the relief valve 18 due to a large flow rate, and the hydraulic circuit, each control valve 14, There was a risk of damaging each of the hydraulic actuators 15, 16, and 17. It is an object of the present invention to provide a safe working machine that does not operate both power sources at once.

[0007]

In order to achieve the above object, an interlock device for a working machine of the present invention is a working machine in which a boom is hoisted and swung by a hydraulic actuator appropriately arranged on the vehicle. In particular, in a working machine including a hydraulic pump driven by an electric motor and a hydraulic pump driven by an engine, the hydraulic actuator is selectively driven to drive the hydraulic actuator. A first detecting means for detecting a starting preparation state or an operating state of the motor and a second detecting means for detecting a starting preparation state or an operating state of the engine are arranged, and the first detecting means is the electric motor. A first restricting means for restricting the starting means of the engine and a second detecting means for detecting the start-up condition or the operating condition of the engine when the starting condition of the engine is detected. In which characterized in that a second regulating means for regulating the starting means of the electric motor when it detects a preparation state or operating state.

[0008]

In the interlock device for a working machine of the present invention configured as described above, when the first detecting means detects the starting preparation state or operating state of the electric motor, the first regulating means operates the engine starting means. The engine is not started while the electric motor is operating because the restriction is imposed so that the engine cannot be started. Further, when the second detecting means detects the engine starting preparation state or the operating state, the second regulating means regulates the starting means of the electric motor so that the electric motor cannot be started. It does not start the electric motor when the is running. Therefore, since both power sources cannot be operated at the same time, it is possible to prevent actuation of each actuator by receiving the discharge amount from both hydraulic pumps and eliminate troubles for that. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An interlock device for a working machine according to the present invention will be described below with reference to FIG. In describing the embodiment of the present invention, the case where it is carried out on the aerial work vehicle A illustrated in FIGS. 2 and 3 and described in the related art will be described below. Therefore, the reference numerals 1 to 18 and the reference numeral A used in the description of the conventional technique are the same in the following description, and the same reference numerals are used and the description thereof is omitted.

In FIG. 1, reference numeral 19 denotes an electromagnetic switch, which is manually closed when receiving power from a commercial power source.
When the current flowing through the electromagnetic switch 19 exceeds a predetermined value, the circuit is automatically opened by the electromagnetic force. Reference numeral 20 denotes an inverter, which receives power supply from any one phase of the high-voltage three-phase AC power supply and converts it into a DC low-voltage power supply.

The DC low-voltage power supply output from the inverter 20 is connected to the battery 22 via the diode 21 so that the battery 22 can be charged. R
Reference numeral 2 denotes a relay connected between the inverter 20 and the diode 21, which corresponds to the first detecting means described in the claims. When the electromagnetic switch 19 is closed, the relay 2 operates to open the normally closed contact R2b. It is configured to open.

Reference numeral 23 is a starting means for the electric motor,
It is configured as follows. Reference numeral 24 denotes an operation switch of the electric motor, which is a normally open switch. 25
Is a stop switch of the electric motor, which is a normally closed switch. The operation switch 24 and the stop switch 25 are connected in series to a series circuit of a normally open contact R3a (corresponding to a second restricting means described in the claims) and a relay MS1 described later, and a high-voltage three-phase alternating current. The power supply is connected from any one phase of the power supplies, and the normally open contact MS1a is connected in parallel to the series circuit of the operation switch 24 and the normally open contact R3a.

Numeral 26 is a device for operating the electric motor 10, which is turned on by a relay MS1 to a high voltage three-phase AC power source.
When a predetermined time elapses after the wiring is started to start the electric motor 10 and the built-in timer starts the Y connection to start the electric motor 10, the Δ connection is performed to operate the electric motor 10, and when stopped, the electric motor 10 is connected in reverse. It is a device that operates to stop.

Reference numeral 27 denotes an engine starting means, which is constructed as follows. Reference numeral 28 denotes a safety relay, which detects a power generation voltage from an alternator (not shown), turns off the output transistor 29 when the power generation voltage is generated, and turns on the output transistor 29 when the power generation voltage is not generated. It is supposed to be.
That is, the output transistor 29 is turned off while the engine 11 is rotating, and the output transistor 29 is turned on while the engine 11 is stopped.

R5 is a starter relay that operates when the output transistor 29 is turned on.
It is connected in series with the output transistor 29. Also,
The starter relay R5 is connected in series with a normally closed contact R2b which opens its contact when the relay R2 is actuated. Therefore, the starter relay R5 is in a state where the electromagnetic switch 19 is opened and power is not supplied from the commercial power source, and
It operates only when the engine 11 is stopped.

R3 is a relay disposed in parallel with the series circuit of the normally closed contact R2b and the starter relay R5, and corresponds to the second detecting means described in the claims, and operates by turning on the output transistor 29. Normally open contact R3a described above
Is designed to close. That is, if the relay R3 does not operate (in other words, if the engine 11 is not in the stopped state), the normally-open contact R3a that is the second restricting means does not close, so that the relay MS1 does not operate even when the operation switch 24 is closed. Therefore, the electric motor 10 cannot be started.

Reference numeral 30 denotes a key switch having two circuits of three positions of OFF, ON, and START, which are ON and STA.
At the RT position, the power from the battery 22 is normally closed contact R
2b and the relay R3 are connected so as to be supplied. In the START position, the start relay R4 is connected to supply power.

Reference numeral 31 denotes a starter motor, which is a normally open contact R4a closed by the operation of the start relay R4 and a normally open contact R5a closed by the operation of the starter relay R5.
It is connected to the battery 22 via the series circuit. Therefore, when the start relay R4 and the starter relay R5 are activated, the starter motor 31 causes the engine 11 to operate.
So that it can be started. (In other words, when the key switch 30 is set to the START position and the start relay R4 is operated while the electromagnetic switch 19 is opened and power is not supplied from the commercial power supply, and the engine 11 is stopped. , Starter motor 31
The engine 11 is thereby started. )

The interlock device for the aerial work vehicle A having the above-described structure requires the key switch 30 to be turned from the OFF position to the ON position without fail.
The electric motor 10 or the engine 11 cannot be started. That is, the relay R3 or the starter relay R5 does not operate unless the key switch 30 is set to the ON position.

Next, the operation will be described. Now the electromagnetic switch 19
Is manually closed to receive power from a commercial power source, drive the electric motor 10, and operate the aerial work vehicle A with the hydraulic power source from the hydraulic pump 12. At this time, key switch 3
0 is, of course, in the ON position. The relay R2, which is the first detection means, is connected to the inverter 2 from the commercial power source.
Power is supplied via 0 and is operating. That is, the relay R2 closes the electromagnetic switch 19 and detects that power is being supplied from the commercial power supply.

It is assumed that the key switch 30 is further moved from the ON position to the START position while trying to drive the engine 11 even though the electric motor 10 is being driven. However, since the relay R2 is operating, the normally-open contact R2b, which is the first restricting means, is open and the starter relay R5 is in a non-operating state. Therefore,
Even if the key switch 30 is moved from the ON position to the START position and the start relay R4 is operated to close the normally open contact R4a contact, the normally open contact R5a contact that is closed by the operation of the starter relay R5 is not closed. The engine 11 cannot be started by 31.

As described above, the relay R which is the first detecting means.
2, the electromagnetic switch 19 is closed to detect that power is being supplied from the commercial power source, and the engine starting means 27 is regulated by the normally-open contact R2b which is the first regulating means.

Next, it is assumed that the engine 11 is driven to operate the aerial work vehicle A with the hydraulic pressure source from the hydraulic pump 13. At this time, the key switch 30 is, of course, in the ON position. The relay R3, which is the second detection means,
Since the engine 11 is rotating, the output transistor 29 is turned off and does not operate. That is, the relay R3 detects that the engine 11 is not in the stopped state.

It is assumed here that the operation switch 24 is closed while trying to drive the electric motor 10 while the engine 11 is being driven. However, since the relay R3, which is the second detecting means, is operating, the relay R3a, which is the second restricting means, remains open to the relay MS1.
Does not operate and the electric motor 10 cannot be started.

Thus, the relay R which is the second detecting means
3 detects that the engine 11 is not in the stopped state, and controls the starting means 23 of the electric motor by the normally-open contact R3a which is the second restricting means.

As described above, since it is possible to prevent both power sources of the electric motor 10 and the engine 11 from operating at the same time, the hydraulic pump 12 and the hydraulic pump 13 can be operated.
It is possible to prevent the actuators from being actuated in response to the discharge amounts from the two hydraulic pumps, and it is possible to eliminate the trouble for that purpose.

In the above-described embodiment, the relay R2 serving as the first detector closes the electromagnetic switch 19 to detect that power is supplied from the commercial power source, and the electric motor 10 is detected.
However, the rotation detector of the electric motor 10 may be provided and the normally closed contact R2b may be opened by the rotation detector when the electric motor 10 is in the rotation state. ..

In the above embodiment, the safety relay 2
Although the stop state or the operating state of the engine 11 is detected by the relay R3 which is the second detector by 8, the oil pressure detector of the engine 11 detects the stop state or the operating state of the engine 11. You can Further, a rotation detector of the engine 11 may be provided to detect the stopped state or the operating state of the engine 11. Next, when the key switch 30 is moved from the ON position to the START position, a start preparation position is added during this time, and when the key switch 30 is positioned at this position, the relay R3 serving as the second detecting means is activated. Alternatively, the starting preparation state of the engine 11 may be detected.

Further, in the above-mentioned embodiment, the case where it is applied to the work vehicle A at high places has been described, but it goes without saying that it can be applied to work machines such as a crane vehicle, a boring column truck, an excavator and the like.

The interlock device for a working machine according to the present invention, which has the above-described configuration and operation, prevents both the electric power sources of the electric motor and the engine from operating at the same time, and therefore is driven by the electric motor. It is possible to prevent the actuation of each actuator by receiving the discharge amount from both the hydraulic pump and the hydraulic pump driven by the engine, and it is possible to eliminate the trouble for that purpose.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an interlock device for a working machine according to the present invention.

FIG. 2 is an explanatory diagram illustrating a hydraulic circuit of an aerial work vehicle.

FIG. 3 is an explanatory diagram illustrating an aerial work vehicle as an example of a work machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 vehicle 3 boom 10 electric motor 11 engine 23 starting means for electric motor 27 starting means for engine R2 first detecting means R3 second detecting means R2b first restricting means R3a second restricting means

Claims (1)

[Claims] 1. A working machine in which a boom is lifted and swung freely by a hydraulic actuator appropriately arranged on a vehicle, and in particular, it comprises a hydraulic pump driven by an electric motor and a hydraulic pump driven by an engine. A work machine configured to drive the hydraulic actuator by selectively using these hydraulic pumps; first detection means for detecting a starting preparation state or an operating state of the electric motor; and a starting preparation of the engine. Second detecting means for detecting a state or an operating state, and a first regulating means for regulating the starting means of the engine when the first detecting means detects the starting preparation state or the operating state of the electric motor. A second regulation for regulating the starting means of the electric motor when the second detecting means detects the starting preparation state or the operating state of the engine. Interlock device for a working machine arranged means.