JP3167612B2 - Split hydraulic unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic unit used for an industrial machine, a construction machine, and the like, and more particularly to a hydraulic unit having a structure divided into several units in consideration of transportation and use.

[0002]

2. Description of the Related Art A hydraulic unit in an industrial machine or construction machine drives a hydraulic pump by an engine or an electric motor to forcibly suck up hydraulic oil in an oil tank, discharge it as pressurized oil, and convert the pressurized oil to a desired pressure. The hydraulic oil is sent to a target actuator outside the hydraulic unit using a directional control valve or the like, and the oil whose work has been completed by the actuator is returned to the oil tank again. In such a hydraulic unit, hydraulic equipment such as a hydraulic pump, an oil tank, a pressure control valve, and a directional control valve as described above is generally mounted on a base frame, and is usually combined into one hydraulic unit.

[0003] However, there are sometimes divided into a hydraulic power unit having only a function of sending out pressure oil, and a control unit which sends out the pressure oil to each actuator by controlling the discharged pressure oil by various control valves according to its use. May be used. That is, if the control unit is adapted to the application, there is an advantage that the hydraulic power unit can be used in common and the hydraulic power unit becomes more versatile. Further, if the hydraulic power unit and the control unit are separated, there is an advantage that the hydraulic power unit and the control unit can be divided and transported by a small truck.

[0004]

As described above, when the hydraulic power unit and the control unit are divided and connected by a hydraulic hose, processing of the hydraulic hose becomes a problem. As the hydraulic hose connecting the hydraulic power unit and the control unit, a number of high-pressure hoses corresponding to the number of hydraulic pumps must be provided.However, low-pressure hoses for sending return oil do not need to be provided for each actuator. Want to reduce the number.

However, reducing the number of low-pressure hoses for return piping increases the size of the hose. As the size increases, there is no self-sealing type quick joint on the market.If an open connection fitting without a self-sealing function is used to connect the return piping of each hydraulic unit, both units must be disassembled during assembly and assembly. It becomes difficult to treat the hydraulic oil in the hose to be tied, and the hydraulic oil may spill around. In addition, when air enters the hose and the hose is connected for operation, a large amount of air in the piping generates cavitation, and depending on the situation, there is a possibility that the hydraulic pump or the like may be damaged.

For this reason, the hoses are divided into hoses of a size that can be used for quick joints. As a result, the number of hoses is increased, the piping space in the hydraulic unit is increased, and the workability of disassembly and assembly is increased. There was a problem that it caused the deterioration of.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a hydraulic unit in which a hydraulic power unit and a control unit are divided and each unit is connected by a hydraulic hose, and the number of hydraulic hoses is reduced to reduce piping space. In addition to improving the workability of disassembly and disassembly, the hydraulic oil can be prevented from leaking to the outside when an open type is used as the fitting for the hydraulic hose. It is an object of the present invention to provide a split hydraulic unit having a configuration capable of removing air and suppressing cavitation when a hydraulic pump is driven.

[0008]

According to a first aspect of the present invention, there is provided a hydraulic power unit having a hydraulic pump and a hydraulic oil tank, and a control unit for distributing hydraulic oil to each actuator. In a split hydraulic unit connected by a detachable hydraulic hose, an open connection fitting without a self-sealing function is provided at a connection part of a low-pressure hose connecting return pipes of the respective units, and a return pipe on a control unit side is provided. In the middle, an inverted U-shaped pipe is provided, a branch pipe is provided at the top of the inverted U-shaped pipe, and a cock is provided at the branch pipe or at a root thereof, and air in the pipe is discharged to the outside or discharged through the pipe through the cock. The air breather to be taken in is provided at a position higher than the oil level of the oil tank of the hydraulic power unit, and the open connection fitting on the hydraulic power unit side and the oil A check valve for preventing backflow of hydraulic oil from an oil tank is provided in the middle of a pipe between the oil tank and a pipe having the check valve between the open connection fitting on the hydraulic power unit side and the oil tank. Another branch pipe is provided, and a hydraulic oil suction hydraulic pump for sucking the hydraulic oil in the low-pressure hose into the oil tank is provided in the branch pipe, and the low-pressure hose is connected to the hydraulic oil suction hydraulic pressure unit when the unit is disassembled. A cock is provided for communicating with the pump and for communicating the inside of the oil tank with the low-pressure hose when assembling the hydraulic unit.

According to a second aspect of the present invention, a control unit is provided.
Between the cock and the directional control valve in the return pipe on the side
Oil from the control unit side by pilot pressure
Oil flow in the opposite direction to the pressure power unit side is allowed
A pilot check valve is provided. Claim
Item 3 has a hydraulic pump and a hydraulic oil tank.
Distributes hydraulic oil to hydraulic power unit and each actuator
And a control unit for
In a split hydraulic unit connected by a hose
The low pressure hose connecting the return pipes of each unit
Provide an open connection fitting without a self-sealing function at the connection part,
Install a branch pipe in the middle of the return pipe on the control unit side.
A cock is provided in the branch pipe, and the cock is distributed through the cock.
An air valve that discharges air inside the pipe or takes in air into the pipe
Raise the riser above the oil level in the hydraulic power unit oil tank.
And the return pipe on the control unit side
Between the directional control valve and the branch pipe connection at
Hydraulic power unit from the control unit side
Pilot that allows oil flow in the opposite direction to the knit side
A valve check valve is provided and the hydraulic power unit side is opened
In the middle of the piping between the mold fitting and the oil tank,
Check valves to prevent backflow of hydraulic oil
Between the open connection fitting on the power unit side and the oil tank
A branch pipe separate from the pipe with the check valve
The hydraulic oil in the low-pressure hose into the branch pipe
A hydraulic pump for sucking hydraulic oil into the inside of the
The low-pressure hose before disassembling the unit.
The hydraulic unit is connected to the hydraulic pump
A cock that connects the inside of the oil tank to a low-pressure hose during assembly
Is provided.

A fourth aspect of the present invention is a control unit.
Connect the cock on the side to the hydraulic oil in the oil tank of the hydraulic power unit.
Characterized by being mounted at the same height as the oil level
You.

[0011]

According to the first aspect, when the operation of the hydraulic unit is stopped and the hydraulic power unit and the control unit are disassembled for transportation or the like, the cock provided on the branch pipe of the control unit is operated to operate the low-pressure hose. To the outside air, and operate the cock provided in the hydraulic power unit to connect the low-pressure hose to the hydraulic oil suction hydraulic pump to drive the hydraulic pump, whereby the hydraulic oil in the low-pressure hose is transferred to the oil tank. Inhale inside. At this time, reverse U
Since the U-shaped piping is provided, air does not enter the directional control valve or the like in the control unit.

On the other hand, when the hydraulic power unit and the control unit are connected via a hydraulic hose, the cock provided in the branch pipe is operated to communicate the low pressure hose to the outside air, and the oil tank and the low pressure hose are connected to each other by hydraulic pressure. The cock is connected by operating the cock in the power unit, and the low pressure hose is filled with hydraulic oil from the oil tank. Thereafter, at the time of work, the outside air is shut off by operating the cock of the control unit, and the circuit through the cock between the low-pressure hose and the hydraulic pump for sucking hydraulic oil and the cock with the oil tank is shut off to turn off the hydraulic pump for driving the actuator in the hydraulic power unit. When activated, the return oil is returned to the oil tank via the check valve.

According to the second and third aspects, the control unit is provided.
A pilot check valve is provided on the return pipe of the knit
Therefore, separate the hydraulic power unit and control unit.
When the low pressure hose is filled with air during
Prevents air from entering the directional control valve in the roll unit
Is done.

According to a fourth aspect of the present invention, a collar provided on the branch pipe portion is provided.
Position was almost the same as the oil level of the oil tank.
When returning hydraulic oil to the low pressure hose,
Automatically fills with hydraulic oil.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural view showing an embodiment of a split type hydraulic unit according to the present invention, in which each device for sucking or filling hydraulic oil in a low pressure hose which is a part of a return pipe. This shows the state of attachment. FIG. 2 is a hydraulic circuit diagram showing the overall configuration of the embodiment.

In FIG. 2, the split hydraulic unit 1 comprises:
It comprises a hydraulic power unit 2 and a control unit 3. In the hydraulic power unit 2, reference numeral 4 denotes an oil tank having an oil supply port 6 and an air breather 5, reference numerals 7 and 8 denote strainers, reference numerals 9 and 10 denote hydraulic pumps driven by motors 11 and 12, reference numerals 13 and 14 denote pressure control valves, and reference numeral 53. Are check valves provided on these secondary pipes.

The discharge pipes of the hydraulic pumps 9 and 10 are connected to the directional control valves 22 and 23 of the control unit 3 through a high-pressure hose 20 and quick joints 16 and 17 which are attached and detached via quick joints 15 and 17, respectively.
8 and is connected by a high-pressure hose 21 which is detachable. The secondary pipes of the directional control valves 22 and 23 are connected to actuators, for example, a hydraulic motor 29 and a hydraulic cylinder 28 via high-speed hoses 30 and 31 which are attached and detached via quick joints 24 and 25, respectively. A high-pressure hose 32 detachable via 27;
33.

Reference numerals 34 and 55 denote return pipes integrated into the control unit 3 side and hydraulic power unit 2 side, respectively, and reference numeral 39 denotes a low-pressure hose connecting these return pipes 34 and 55 to each other. Open connection fittings 3 with no self-sealing function at both ends
7 and 38, it is detachably connected to the return pipes 34 and 55. The cooler 40, the filter 41, and the check valve 42 are provided in the return pipe 55 on the hydraulic power unit 2 side.

Reference numeral 50 denotes a drain pipe of the hydraulic motor 29;
Is a drain hose, 19 is a quick joint that detachably connects the drain hose 51 to the hydraulic power unit 2, and 52 is a check valve provided on the drain pipe on the hydraulic power unit side.

The above components are used when a normal hydraulic unit is operated.
The structure for disassembling the hydraulic unit, draining oil during assembly, and filling the oil will be described. First, the hydraulic power unit 2 will be described. Reference numeral 56 denotes a pipe provided between the connection fitting 38 and the oil tank 4 and branched from the return pipe 55. The branch pipe 56 is operated when the hydraulic unit is disassembled. A hydraulic pump 47 for sucking hydraulic oil in a low-pressure hose 39 driven by a motor 48, and filters 45, 4
6 and a check valve 49, and a suction side pipe 56a of a hydraulic pump 47 which is a part of the branch pipe 56.
Is provided with a cock 43. The pipe 57 and the cock 44 provided in the pipe 57 are provided to fill the low-pressure hose 39 with the hydraulic oil at the time of connection between the units, and one end of the pipe 57 is located below the oil level of the oil tank 4. The other end is connected between the cock 43 and the hydraulic pump 47 in the suction side pipe 56a.

On the control unit 3 side, an inverted U-shaped pipe 58 constituting a part of the return pipe 34 is provided.
As shown in FIG. 2, a branch pipe 5 is provided at the top of the inverted U-shaped pipe 58.
9, a cock 35 is provided in the branch pipe 59, and an air breather 36 which discharges air in the pipe to the outside or takes in the pipe via the cock 35 is higher than the oil level of the oil tank 4 of the hydraulic power unit 2. Position. The cock 35 may be a three-way cock provided at the root of the branch pipe 59. In this case, the three-way cock is
And a switching position for communicating the low-pressure hose 39 with the outside air.

As shown in FIG. 1, the oil tank 4 is located above the hydraulic power unit 2, and the cocks 43, 44 are located below the oil tank 4. In addition, the open-type fitting 38 of the low-pressure hose 39 constituting the return pipe on the hydraulic power unit 2 side is provided below the hydraulic power unit 2, while the open-type fitting 37 on the control unit 3 side is located above the control unit 3. The cock 35 and the air breather 36 are arranged near the connection fitting 37, thereby facilitating discharge of the air accumulated at the top of the inverted U-shaped pipe 58 to the outside. The height of the cock 35 is set substantially in accordance with the height of the oil level of the oil tank 4 of the hydraulic power unit 2.

Next, the operation of this embodiment will be described. During normal operation of the hydraulic unit, cocks 35, 43,
44 is closed, and the hydraulic pump 47 is stopped. The operation of the hydraulic pumps 9 and 10 causes the hydraulic oil in the oil tank 4 to be sucked up and discharged. The discharged oil is a high pressure hose 20,
Via 21, they are sent to the respective directional control valves 22, 23. Then, after operating the hydraulic motor 29 and the hydraulic cylinder 28 which are actuators corresponding to the respective directional control valves 22 and 23, the return oil is sent to the directional control valves 22 and 23 again, and the return pipe 34 and the inverted U-shaped pipe are returned. After passing through 58, it returns to the oil tank 4 via the connection fitting 37, the low-pressure hose 39, the connection fitting 38, the cooler 40 of the return pipe 55, the filter 41, and the check valve 42. In FIG. 1, solid arrows indicate the flow of hydraulic oil when the hydraulic unit 1 operates.

Next, the case of disassembly into the hydraulic power unit 2 and the control unit 3 will be described. In this case, stop the operation of the hydraulic pumps 9 and 10, and
Remove the 0 and 21 from the quick joints 15-18. Also, the drain hose 51 is connected to the quick joint 19.
Remove from Then, the cocks 35 and 43 are opened, and the cock 44 is kept closed. Thus, when the hydraulic pumps 9 and 10 are stopped, the cock 35
, The hydraulic oil does not leak outside because the air breather 36 is located at a position higher than the oil level of the oil tank 4.

As described above, the cocks 35, 43, and 44 are operated to operate the hydraulic pump 47. As a result, air enters from the air breather 36, and the hydraulic oil in the low-pressure hose 39 is sucked in the path indicated by the dotted arrow and returned to the oil tank 4. At this time, the cock 44 is closed and the return pipe 55
Is provided with a check valve 42, and only the hydraulic oil at the top of the inverted U-shaped pipe 58 is sucked by the hydraulic pump 47, so that only the hydraulic oil in the pipe line partitioned by these is supplied to the oil tank 4. The pipe will be sucked in, and eventually the entire pipe will be filled with air. Therefore, when the low-pressure hose 39 is removed, the hydraulic oil does not flow out. Further, since the discharge pipe and the return pipe 55 of the hydraulic pump 47 are provided with the check valves 49 and 42, even if the hydraulic pump 47 is stopped,
Does not flow out to the low pressure hose 39 side.

Next, the case where the hydraulic power unit 2 and the control unit 3 are connected will be described. First, the high pressure hoses 20 and 21 and the drain hose 51 are connected via the quick joints 15 to 19. Then, the low-pressure hose 39 is connected via the connection fittings 37 and 38.
Then, the cocks 35, 43, and 44 are opened. As a result, the hydraulic oil in the oil tank 4 is
After passing through 4 and 43, the low pressure hose 39 is filled. here,
As shown in FIG. 1, since the height of the cock 35 is set to be substantially the same as the height of the oil level of the oil tank 4, the air in the low-pressure hose 39 is automatically pushed out by the hydraulic oil according to the siphon principle. The air is then discharged to the outside via the air breather 36. As a result, the return pipe 55, the low pressure hose 39, and the reverse U
The inside of the V-shaped pipe 58 is filled with hydraulic oil. And cock 3
5, 43 are closed, and the operation state is established.

Here, since the oil level of the hydraulic oil in the oil tank 4 is not constant depending on the operation state of the actuator, the inverted U-shaped pipe 58 is not always filled with the hydraulic oil, and air may remain. When the operation is started, the air dissolves into the working oil, and the air is discharged into the oil tank 4 during the circulation.

FIGS. 3 and 4 are a configuration diagram and a hydraulic circuit diagram, respectively, showing another embodiment of the present invention drawn corresponding to FIGS. 1 and 2, respectively. 34 is provided with a pilot check valve 54 which is opened by hydraulic oil through a pilot pipe 62 from the hydraulic pump 9 or 10.

According to the present embodiment, the inverted U-shaped piping 58
3, the cock 35 at the level of the oil level in the oil tank 4 is opened and the hydraulic pump 47 sucks the air in the low-pressure hose 39 even if the pipe is a horizontal pipe as shown by the pipe 60 in FIG. The pilot check valve 54 prevents air from entering the return pipe 34 from the pilot check valve 54 toward the direction switching valves 22 and 23. Further, according to the present embodiment, the branch pipe 61 having the cock 35 and the air breather 36 for sucking or removing air can be made thin. Further, the upper piping structure in the control unit 3 is simplified. Further, a pilot check valve 54 may be provided in the inverted U-shaped pipe 58 shown in FIG. 1 as shown by a two-dot chain line.

In this embodiment, the pipe 57 having the cock 44 opened when the hydraulic unit is connected is connected to the suction pipe 56a between the fitting 38 and the cock 43 (connected to the return pipe 55). The pipe 5
One end of 7 may be connected between the cock 43 and the hydraulic pump 47. If the pipe 57 is connected between the cock 43 and the connection fitting 38 as in this embodiment, the cock 43 does not always need to be opened when the hydraulic unit is connected. However, in the embodiment shown in FIGS. 1 and 2, if the cock 44 is opened with the cock 43 closed and the hydraulic pump 47 is operated, the filters 45 attached to the front and rear of the hydraulic pump 47 are removed.
At 46, there is an effect that the operating oil in the oil tank 4 can be filtered and washed. The pilot check valve 54 only needs to be opened by a hydraulic pump that operates when the hydraulic unit 1 operates, and when a pilot pump is provided, it may be opened by the discharge oil of the pilot pump. Also,
The cocks 43 and 44 are three-way cocks provided at the connection between the suction side pipe 56a and the pipe 57. The three-way cocks are provided with a switching position for communicating the low-pressure hose 39 with the hydraulic pump 47 for sucking hydraulic oil, and a low-pressure hose 39. And a switching position at which the oil tank 4 and the hydraulic pump 47 are communicated with each other.

In the above embodiment, an example in which one low-pressure hose 39 is provided has been described. However, when the number of actuators is large, a plurality of low-pressure hoses 39 may be provided.

[0032]

According to the first aspect of the present invention, in the split hydraulic unit, even if open-type fittings are used at both ends of the low-pressure hose for connecting the hydraulic power unit and the control unit, when the hydraulic unit is disassembled, the inside of the low-pressure hose or the like can be reduced. Since the hydraulic oil can be sucked into the oil tank, the hydraulic oil does not flow out when the low-pressure hose is removed. Further, when connecting the units, a low-pressure hose filled with air is connected. However, simply opening the cock discharges the air in the low-pressure hose to the outside and fills the working oil. For this reason, the occurrence of cavitation can be suppressed when the hydraulic pump for driving the actuator is driven.

Since a large-diameter low-pressure hose using an open connection fitting can be used, the number of low-pressure hoses can be reduced to a small number such as one, and as a result, the hydraulic pressure between the hydraulic power unit and the control unit can be reduced. The number of hoses can be reduced, so that the piping space can be reduced and the workability of disassembly and assembly can be improved.

According to the second and third aspects , the control unit
Instead of using an inverted U-shaped pipe in the middle of the return pipe on the cut side
Or in addition to the inverted U-shaped piping,
Pilot check opened by pressure on pump discharge side
With the valve, the hydraulic power unit and control unit
When the low pressure hose is filled with air when separating the knit
Air to the directional control valve etc. in the control unit
Is prevented by the pilot check valve. Ma
The connection between the pilot check valve and the open fitting
If the pipe is installed horizontally, the branch pipe can be made thinner.
And the upper piping structure of the control unit is simple
Become.

According to the fourth aspect, the control unit
Connect the cock on the side to the hydraulic oil in the oil tank of the hydraulic power unit.
The hydraulic oil is mounted at the same height as
No more and no less than the cock of the control unit
Air to the hydraulic circuit.
Mixing can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a split type hydraulic unit according to the present invention, showing how various devices are attached for drawing or filling hydraulic oil in a low pressure hose of a return pipe.

FIG. 2 is a hydraulic circuit diagram showing an overall configuration of the embodiment.

FIG. 3 is a view corresponding to FIG. 1 of another embodiment of the split hydraulic unit according to the present invention.

4 is a diagram corresponding to FIG. 2 of the embodiment of FIG. 3;

[Explanation of symbols]

1: hydraulic unit, 2: hydraulic power unit, 3: control unit, 4: oil tank, 5, 36: air breather, 6: oil inlet, 7, 8, 41, 45, 46: filter, 9, 10: hydraulic pump , 11, 12: motor, 1
3, 14: pressure control valve, 15 to 19, 24 to 27: quick joint, 20, 21, 30 to 33: high pressure hose, 22, 23: directional switching valve, 28: hydraulic cylinder, 2
9: hydraulic motor, 34, 55: return pipe, 35, 43,
44: cock, 37, 38: open fitting, 39: low pressure hose, 42, 49, 52, 53: check valve, 4
7: Hydraulic pump for sucking hydraulic oil in low pressure hose, 54: Pilot check valve, 56: Branch pipe, 56a: Suction side pipe, 58: Reverse U-shaped pipe, 59, 61: Branch pipe

Claims (4)

(57) [Claims] A split hydraulic unit in which a hydraulic power unit having a hydraulic pump and a hydraulic oil tank and a control unit for distributing hydraulic oil to each actuator are connected by a detachable hydraulic hose. An open connection fitting without a self-sealing function is provided at the connection part of the low-pressure hose connecting the return pipes of the units, and the middle of the return pipe on the control unit side is formed as an inverted U-shaped pipe, at the top of the inverted U-shaped pipe. A branch pipe is provided, and a cock is provided at the branch pipe or at the root thereof, and an air breather which discharges air in the pipe to the outside or takes in the pipe via the cock is located at a position higher than the oil level of the oil tank of the hydraulic power unit. To prevent backflow of hydraulic oil from the oil tank in the middle of the pipe between the open connection fitting on the hydraulic power unit side and the oil tank. A check valve for stopping the operation is provided, and a branch pipe separate from the pipe having the check valve is provided between the open connection fitting on the hydraulic power unit side and the oil tank, and the hydraulic oil in the low-pressure hose is provided in the branch pipe. A hydraulic pump for sucking hydraulic oil into the oil tank, connecting the low pressure hose to the hydraulic pump for hydraulic oil suction when disassembling the unit, and connecting the inside of the oil tank to the low pressure hose when assembling the hydraulic unit. A split-type hydraulic unit having a cock. (2)In claim 1,  Control unit sideThe cock in the return pipe
Between the directional control valve and the pilot pressure
Oil in the opposite direction from the hydraulic unit to the hydraulic unit
Flow is acceptableProvision of pilot check valve
A split type hydraulic unit characterized by the following. (3)Oil with hydraulic pump and hydraulic oil tank
Distributes pressure oil to the pressure power unit and each actuator
And a control unit for
In the split type hydraulic unit connected by the base, Connection of low-pressure hoses connecting the return pipes of each unit
Provide an open connection fitting without a self-sealing function in the part, Install a branch pipe in the middle of the return pipe on the control unit side.
Ke A cock is provided on the branch pipe, and inside the pipe through the cock.
An air breeze that discharges air to the outside or takes in the piping
Is higher than the oil level in the oil tank of the hydraulic power unit.
Installed in the Direction cut in the return piping on the control unit side
Pilot pressure between the valve and the branch pipe connection
From the control unit side to the hydraulic power unit side
Pilot valve check valve that allows oil flow in one direction
Provided, The open connection fitting and oil tank on the hydraulic power unit side
Backflow of hydraulic oil from the oil tank in the middle of the piping between
Check valve to stop, The open connection fitting and oil tank on the hydraulic power unit side
Between the pipe having the check valve and the
A pipe is provided, and the hydraulic oil in the low-pressure hose is
Hydraulic oil suction hydraulic pump for sucking into the tank is provided, When disassembling the hydraulic power unit,
To the hydraulic oil suction hydraulic pump.
Connect the oil tank to the low-pressure hose during knit assembly
I have a cock A split-type hydraulic unit, characterized in that: 4. In any one of claims 1 to 3,  Connect the cock on the control unit side to the hydraulic power unit.
Oil level of the oil tankSame asTake it to height
A split hydraulic unit characterized by being attached.