JP6466825B2 - Hydraulic drive device and air conditioner for work machine - Google Patents

Description

  The present invention relates to a hydraulic drive device and an air conditioner for a work machine.

  In a working machine such as a crawler crane, an air conditioner (air conditioner) is installed in the cab. However, the engine may be stopped at the time of operation standby such as a slinging operation, and in this case, the air conditioner is also stopped. Therefore, when the engine is stopped, an air conditioner is driven using an external power source (Patent Document 1). When this is applied to a work machine, an external power source for driving the air conditioner when the engine is stopped is supplied from the lower traveling body to the electric motor of the upper swing body via the rotary joint, and the air motor is driven by the electric motor. Conceivable.

JP 2012-25225 A

  Conventional rotary joints are designed to transmit and receive weak electrical signals between the upper swing body and the lower traveling body. However, according to the above-described method, it is difficult to transfer the high-power electric power that drives the electric motor by using the conventional rotary joint used for the low-power signal. For this reason, a rotary joint capable of using strong electric power is required, and the increase in size and cost of the rotary joint is a problem. In addition, such a problem is not a problem peculiar to the working machine carrying an air conditioner.

  A hydraulic drive device for a work machine according to a first aspect of the present invention includes a first hydraulic pump provided on an upper swing body and driven by a prime mover, and a second hydraulic pump provided on the upper swing body and driven by the prime mover. A first hydraulic actuator provided on the upper swing body and driven by the discharge oil of the first hydraulic pump; a second hydraulic actuator provided on the lower traveling body and driven by the discharge oil of the second hydraulic pump; An electric motor provided in the lower traveling body and driven by an external power source, a third hydraulic pump provided in the lower traveling body and driven by the electric motor, and provided in the lower traveling body, between the external power source and the electric motor A switch provided in between, a commander provided on the upper swing body for commanding opening and closing of the switch, and a discharge oil of the second hydraulic pump provided on the upper swing body to the second hydraulic actuator, 3rd hydraulic pump And a rotary joint provided with a signal line for transmitting a command to the switch.

  According to the present invention, the first hydraulic actuator of the upper swing body, for example, the air conditioning hydraulic motor is driven by the discharge oil of the electric hydraulic pump provided in the lower traveling body. In particular, since the lower traveling body switch is opened and closed according to the command of the upper swing body commander, the electric motor of the lower traveling body is started, so a large rotary joint for supplying strong electric power is provided. It becomes unnecessary and the cost concerning a rotary joint is reduced.

It is an external appearance side view of a crane. It is a hydraulic / electric circuit diagram of an air conditioner when no external power supply is introduced. It is a hydraulic / electric circuit diagram of an air conditioner when an external power supply is introduced.

Hereinafter, an embodiment of a hydraulic drive device for a work machine according to the present invention will be described with reference to FIGS. This embodiment is an example in which a hydraulic drive device is applied to an air conditioner for a crawler crane.
FIG. 1 is an external side view of a crane having an air conditioner according to the present embodiment. The crane includes a lower traveling body 1, an upper revolving body 2 that is pivotably mounted above the lower traveling body 1 via a swivel wheel, and a boom 3 that is pivotally supported by the upper revolving body 2. Have A plurality of winch drums 5 are mounted on the main frame 4 of the upper swing body 2, and the boom 3 is raised or lowered by driving each winch drum 5, or the hook 6 is moved up and down from the tip of the boom.

  In this type of crane, the upper revolving unit 2 is disassembled from the lower traveling unit 1 during transportation in order to reduce the transportation weight, and the upper revolving unit 2 is assembled on the lower traveling unit 1 at the work site. When the crane is disassembled and assembled, the main frame 4 is jacked up by the jackup device. Moreover, the crawler crane of the embodiment includes an air conditioner.

  FIG. 2 is a hydraulic / electric circuit diagram showing details of the jack-up device, the air conditioner, and the electrical components of the crawler crane according to the embodiment. Below the dotted line in the figure is a circuit diagram of various hydraulic equipment and electrical equipment installed in the lower traveling body 1, and above the dotted line is a circuit diagram of various hydraulic equipment and electrical equipment installed in the upper swing body 2. . In FIG. 2, a pipeline through which pressure oil mainly circulates is indicated by a solid line, and a weak electric system wiring is indicated by a two-dot chain line. The pipe D is a drain line.

  The upper swing body 2 is provided with a cab that is air-conditioned by an air conditioner, and an engine 10, an upper air-conditioning hydraulic pump 12 driven by the engine 10, and a jack-up hydraulic pump 11 are mounted behind the cab. ing.

  The upper swing body 2 is provided with a battery 24, an engine start key switch 36, a fuselage electrical component 25, an external power supply introduction switch 22, and a relay 23 as upper electrical components. The key switch 36 and the external power supply introduction switch 22 are installed in the cab. The key switch 36 is switched between a starter position for outputting a starter activation signal, an ON position for supplying a power supply voltage, and an OFF position. The starter activation signal activates the starter of the engine 10 to start the engine 10. In the ON position, a power supply voltage is applied to the external power supply introduction switch 22 and the relay 23. The relay 23 to which the power supply voltage is applied constitutes a circuit so that power generated by a generator 15 described later is supplied to the battery 24. At this time, both the electric power of the battery 24 and the electric power of the generator 15 are supplied to the fuselage electrical component 25.

(Air conditioner)
The air conditioner includes an upper air conditioning hydraulic pump 12 driven by the engine 10, an air conditioning hydraulic motor 14 driven by pressure oil discharged from the upper air conditioning hydraulic pump 12, and a drive shaft of the air conditioning hydraulic motor 14. And an air conditioning compressor 16 connected thereto. As will be described later, the air conditioner also includes a lower air conditioning hydraulic pump 33 driven by the electric motor 32.
The oil discharged from the upper air conditioning hydraulic pump 12 is supplied to the hydraulic motor 14 through the check valve 13, and the hydraulic motor 14 rotates. A check valve 21 is provided on the downstream side of the check valve 13 so that the discharged oil flows only into the air conditioning hydraulic motor 14.
A generator 15 and an air conditioning compressor 16 are connected to the air conditioning hydraulic motor 14, and the generator 15 generates power by the rotational force of the hydraulic motor 14, and the air conditioning compressor 16 compresses the refrigerant. The refrigerant circulates in an air conditioning refrigeration cycle (not shown) and is compressed and expanded. Thereby, heat exchange is performed between the evaporator installed in the cab and the air in the cab, thereby cooling the cab.

The air conditioner can operate by receiving power from an external power source when the engine is stopped. Therefore, the air conditioner includes an air conditioning hydraulic source provided in the lower traveling body 1.
The air-conditioning hydraulic power source includes an outlet 30 that receives power from an external power source, an electric motor 32 that is driven by power from the external power source, a relay 31 that is provided in a circuit that supplies the external power source power to the electric motor 32, And a lower air conditioning hydraulic pump 33 driven by a motor 32.

The relay 31 is a relay switch that is closed by the switching operation of the external power supply introduction switch 22 to the external power supply introduction position and opened at the external power supply non-introduction position. Between the lower air conditioning hydraulic pump 33 and the air conditioning hydraulic motor 14, a check valve 34, a rotary joint 26, an on-off valve 20, and a check valve 21 are arranged. When the external power supply introduction switch 22 is switched to the external power supply introduction position, the on-off valve 20 is switched to the low position, and the discharge oil of the lower air conditioning hydraulic pump 33 is supplied to the check valve 34, the rotary joint 26, the on-off valve 20, It is supplied to the air conditioning hydraulic motor 14 via the check valve 21. In response to the supply of the discharged oil, the air conditioning hydraulic motor 14 rotates, the compressor 16 rotates, the refrigerant is compressed, and cold air blows out from the evaporator in the cab.
When the external power supply introduction switch 22 is switched to the external power supply non-introduction position, the relay 31 is opened, the electric motor 32 is not driven, and the lower air conditioning hydraulic pump 33 does not discharge pressure oil.

(Jack-up device)
The jack-up device includes a jack-up hydraulic pump 11 driven by an engine 10 provided on the upper swing body 2 and a jack-up provided on the lower traveling body 1 and extending and contracting with oil discharged from the jack-up hydraulic pump 11. A cylinder 40 and a jack-up switching valve 28 that switches a direction in which oil discharged from the jack-up hydraulic pump 11 flows into the jack-up cylinder 40 are provided. Further, a switching valve 17, a check valve 19, and an on-off valve 27 are arranged in series between the jackup hydraulic pump 11 and the jackup switching valve 28. A rotary joint 26 is provided between the check valve 19 provided in the upper swing body 2 and the on-off valve 27 provided in the lower traveling body 1.

  The jack-up device can be used when the external power supply introduction switch 22 is switched to the external power supply non-introduction position. When the external power supply introduction switch 22 is switched to the external power supply non-introduction position, both the on-off valve 20 and the on-off valve 27 are switched to the A position. The lower air conditioning hydraulic pump 33 is stopped. The oil discharged from the jackup hydraulic pump 11 is guided to the switching valve 17, the check valve 19, the rotary joint 26, the on-off valve 27, and the jackup switching valve 28. When the jack-up switching valve 28 is operated, the jack is raised and the 40 is expanded and contracted. The on-off valve 27 is switched to the “B” position when the air conditioner is operated by an external power source, and oil discharged from the lower air conditioning hydraulic pump 33 is prevented from flowing into the jack-up switching valve 28.

The operation of the air conditioner configured as described above will be described.
(When external power supply is not installed)
FIG. 2 is a circuit diagram of the air conditioner when no external power supply is introduced.
When the external power supply introduction switch 22 is switched to the external power supply non-introduction position and the key switch 36 is operated to the starter position, a start signal is transmitted to the engine 10 and the engine 10 is started. Then, the upper air conditioning hydraulic pump 12 is driven by the engine 10, pressure oil is supplied to the air conditioning hydraulic motor 14, and the generator 15 and the air conditioner 16 are driven. Thereby, the cab of the crane is air-conditioned and the battery 24 is charged.
An air conditioning switch that turns on and off the use of the air conditioner may be provided.

  When the external power supply is not introduced, the switching signal I is output from the external power supply introduction switch 22. This switching signal I is output to the on-off valve 20, the on-off valve 20 is switched to the A position, the P port and B port of the on-off valve 20 are shut off, and the T port and A port are communicated. In other words, the oil discharged from the jackup hydraulic pump 11 is blocked by the on-off valve 20 and is guided to the on-off valve 27 of the jackup device through the rotary joint 26. When jackup is necessary, when the jackup switching valve 28 is operated, the main frame 4 is jacked up by the pressure oil supplied to the jackup cylinder 40.

(When an external power supply is introduced)
FIG. 3 is a circuit diagram of the air conditioner when the external power supply is introduced.
When the operator switches the key switch to the OFF position in the work standby state, the engine 10 is stopped, the discharge of pressure oil from the upper air conditioning hydraulic pump 12 is also stopped, and the air conditioning hydraulic motor 14 is stopped. When air conditioning in the cab is required, the operator first switches the key switch 36 to the ON position and switches the external power supply introduction switch 22 to the external power supply introduction position. By the switching signal O output from the external power supply introduction switch 22, the on-off valve 20 and the on-off valve 27 are switched to the lower position, and the relay 31 provided in the lower traveling body 1 is closed.

When the relay 31 is closed, the external power supply from the outlet 30 is supplied to the air conditioning electric motor 32, and the lower air conditioning hydraulic pump 33 rotates to discharge the pressure oil. Since the on-off valve 27 is switched to the low position, the oil discharged from the lower air conditioning hydraulic pump 33 is prohibited from flowing into the jack-up switching valve 28. The pressure oil discharged from the lower air conditioning hydraulic pump 33 flows into the air conditioning hydraulic motor 14 through the rotary joint 26, the on-off valve 20, and the check valve 21, and the air conditioning compressor 16 is driven to rotate.
Thus, the air conditioner can be used by turning on the external power supply introduction switch 22 even when the engine 10 is stopped.

According to the embodiment described above, the following operational effects can be obtained.
(1) An air conditioner for a work machine according to an embodiment is provided in an upper swing body and is driven by an engine 10 and an upper air conditioning hydraulic pump 12 and is provided in the upper swing body and is used for jack-up that is driven by the engine 10. An air conditioning hydraulic motor 14 provided on the hydraulic pump 11 and the upper rotating body and driven by the discharge oil of the upper air conditioning hydraulic pump 12, and provided on the lower traveling body and driven by the discharge oil of the jackup hydraulic pump 11. Jack-up cylinder 40, an electric motor 32 provided in the lower traveling body and driven by an external power source, a lower air conditioning hydraulic pump 33 provided in the lower traveling body and driven by the electric motor 32, and a lower traveling A switch 31 provided between the external power source and the electric motor 32, a commander 22 provided on the upper swing body for commanding opening / closing of the switch 31, In addition to guiding the discharge oil of the jack-up hydraulic pump 11 provided in the revolving structure to the jack-up cylinder 40, a conduit for supplying the discharge oil of the lower air-conditioning hydraulic pump 33 to the air-conditioning hydraulic motor 14 is formed. And a rotary joint 26 provided with a signal line for transmitting the command to the switch 31.

In the air conditioner of such an embodiment, the lower traveling body 1 is provided with the lower air conditioning hydraulic pump 33 driven by the electric motor 32, and the air conditioning hydraulic motor of the upper swing body 2 is discharged by the lower air conditioning hydraulic pump 33. 14 was driven. In addition, in the rotary joint 26, the pipe connected to the discharge pipe from the lower air conditioning hydraulic pump 33 is also used as the jack-up pipe, so it is necessary to provide a new pipe in the rotary joint 26. Therefore, an increase in the size of the rotary joint 26 can be prevented. Also, an electric motor 32 driven by external power supply power is installed in the lower traveling body 1, a relay 31 that controls supply / cutoff of power to the electric motor 32 is installed in the lower traveling body 1, and an open / close command for the relay 31 is provided. Only a weak electric signal for use was exchanged with a rotary joint. Therefore, it is not necessary to provide an electric circuit for a strong electric signal in the rotary joint 26, and the enlargement can be similarly prevented. According to the air conditioner configured as described above, the cost related to the rotary joint 26 is reduced.
(2) In the air conditioner for the work machine of (1) above, when a command to close the relay 31 is output from the external power supply introduction switch 22, the pressure oil discharged from the lower air conditioning hydraulic pump 33 is supplied to the jackup cylinder 40. Further provided is an on-off valve 27 for closing the inflow pipe line.
Thereby, the discharge oil conduit of the lower air conditioning hydraulic pump 33 and the pressure oil supply conduit to the jack-up cylinder 40 can be used together.

The above embodiment can be carried out with the following modifications.
(1) In the above, (a) the lower traveling body 1 is transmitted by transmitting the start / stop command output by the external power supply introduction switch 22 of the upper swing body 2 to the relay 31 of the lower traveling body 1 through the rotary joint 26. The electric motor 32 is started / stopped. (B) Of the pipes that supply the oil discharged from the lower air conditioning hydraulic pump 33 of the lower traveling body 1 to the air conditioning hydraulic motor of the upper swing body 2, the lower traveling body is the pipe in the rotary joint 26. Also used as a pressure oil supply line to the jack-up cylinder 40 of No. 1.
In the embodiment, the enlargement of the rotary joint 26 can be prevented by the above (a) and (b). However, the external power supply that outputs the start / stop command by using the hydraulic line in the rotary joint 26 is also used. By arranging the introduction switch 22 other than the upper swing body 2, the weak electrical system wiring provided in the rotary joint 26 may be omitted. That is, the external power supply introduction switch 22 may be provided in the lower traveling body 1 or in a remote device away from the crane.

(2) In the above, the air conditioning hydraulic motor 14 provided on the upper swing body 2 is driven by the oil discharged from the lower air conditioning hydraulic pump 33. However, a hydraulic drive device that drives hydraulic actuators other than the air conditioning hydraulic motor 14 installed in the upper swing body 2 with oil discharged from a hydraulic pump installed in the lower traveling body 1 may be used.
(3) In the above, the case where the pipe for supplying pressure oil to the jack-up cylinder 40 installed in the lower traveling body 1 and the discharge pipe for the lower air conditioning hydraulic pump 33 are used has been described. However, a hydraulic drive device that also serves as a conduit for a hydraulic actuator other than the jack-up cylinder 40 may be used.

(4) Although the upper air conditioning hydraulic pump 12 is driven by the engine 10 in the above, the present invention can also be applied to an air conditioner driven by an electric motor. In this case, the electric motor may be driven by receiving electric power from a generator that generates electric power by rotating with the driving force of the engine.
(5) Although the crawler crane has been described above, the present invention can be applied to various work machines having an upper swing body and a lower traveling body such as a hydraulic excavator.

  The present invention is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. .

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving body 10 Engine 11 Jackup hydraulic pump 12 Upper air conditioning hydraulic pump 13, 19, 21, 34 Check valve 14 Air conditioning hydraulic motor 15 Generator 16 Compressor 20, 27 On-off valve 22 External power supply introduction Switch 26 Rotary joint 31 Relay 32 Electric motor 33 Hydraulic pump for lower air conditioning 40 Jack-up cylinder

Claims (3)

A first hydraulic pump provided in the upper swing body and driven by a prime mover;
A second hydraulic pump provided on the upper swing body and driven by the prime mover;
A first hydraulic actuator provided on the upper swing body and driven by oil discharged from the first hydraulic pump;
A second hydraulic actuator provided on the lower traveling body and driven by oil discharged from the second hydraulic pump;
An electric motor provided in the lower traveling body and driven by an external power source;
A third hydraulic pump provided on the lower traveling body and driven by the electric motor;
A switch provided in the lower traveling body, provided between the external power source and the electric motor;
A command device provided on the upper swing body for commanding opening and closing of the switch;
A conduit is formed for guiding the discharge oil of the second hydraulic pump provided in the upper swing body to the second hydraulic actuator and supplying the discharge oil of the third hydraulic pump to the first hydraulic actuator; And a rotary joint provided with a signal line for transmitting the command to the switch. The hydraulic drive device for a work machine according to claim 1,
The first and third hydraulic pumps are upper and lower air conditioning hydraulic pumps, the first hydraulic actuator is an air conditioning hydraulic motor that drives an air conditioning compressor, and the second hydraulic actuator is a jack-up cylinder. Hydraulic drive device for work machines. The hydraulic drive device for a work machine according to claim 2,
When a command to close the switch is output from a command device, the control device further includes an open / close valve that closes a pipeline through which pressure oil discharged from the lower air conditioning hydraulic pump flows into the jackup cylinder. Hydraulic drive device for work machines.

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