JPS5865827A - Oil-pressure circuit for civil work and construction machine - Google Patents

Abstract

PURPOSE:To allow the straight running of a civil work and construction machine having plural oil-pressure pumps as driving sources by using a contrived circuit constitution around the pumps to supply pressure oil to left- and right-handed running motirs when operating various actuators during the running period. CONSTITUTION:For an oil-pressure shovel, direction switching valves 21 and 23 to operate a bucket cylinder 13 and right-side running motor 7 are connected in parallel to the first oil-pressure pump 20. Also, direction switching valves 26, 29, and 25 to operates a turning motor 3, a boom cylinder 11, and an arm cylinder 12 are connected in parallel to the second oil-pressure pump 24, and a direction switching valve 27 for a left-side running motor 5 is connected in tandem to the downstream side of the arm direction switching valve 25. Then, the input port of the direction switching valve 27 and the discharge oil supply circuit of the oil-pressure pump 24 are connected with a circuit 33 having a load check 31c and a throttle 34 on its midway.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic circuit for a civil engineering/construction machine such as a hydraulic excavator equipped with a plurality of actuators.

In general, a civil engineering/construction machine, such as a hydraulic excavator, is equipped with a rotating body, a running body, and attachments such as a boom, arm, and packet.
y m by an actuator such as a packet cylinder
-,;reooAnd these actuators are 1μ
J 9J It is controlled by the warrior box. FIG. 1 is a side view 11j1 showing the overall construction of the gamma field pressure shovel, and FIG. 2 is a half-view of FIG. 1.

In these figures, 1 is a revolving body, which is equipped with a rotating body 2, a rotating body, a motor 3. Rotate by driving. 4 is a left truck, which is driven by a left traveling motor 5. 6 is the right truck, and the N is driven by the stone row motor 7.
JA/s jli! I do it. 8 is boom, 9 is arm,
Numeral 10 is a packet, and these constitute a work. 11 is a boom cylinder that operates the boom 8;
An arm cylinder 13 is used to operate the double arm 9, and a packet cylinder 13 is used to operate the packet 10.

Figure A3 is a circuit diagram showing an example of a conventional hydraulic circuit installed in the hydraulic excavator mentioned above. In these figures,
20 is a first hydraulic pump, and 2] is a packet recirculation valve, which connects the first hydraulic pump 20 and the packet cylinder 1.
3 and φ. Reference numeral 22 denotes a boom directional switching valve, which is interposed between the packet directional switching valve 21 and the boom cylinder 11. Reference numeral 23 designates a directional control valve for right-hand travel; a directional control valve 22 for arm, a directional control valve 22 for arm 1', and a directional control valve 22 for right-hand travel; The valve 23 is connected in parallel to the first hydraulic pump 20. Gamma field of Ki 1 and 1 Nibomb 20, directional switching valves 21, 22, 23. and a packet cylinder 13,
The boom cylinder 11 and the young lip motor 7 constitute one independent hydraulic circuit.

Further, 24 is a second hydraulic pump, and 25 is an arm directional control valve, which is connected to the second hydraulic pump 24 and the arm cylinder 1.
It is interposed between 2 and 2. 26 is a turning directional control valve,
It is interposed between the arm directional switching valve 25 and the swing motor 3. This is a 27-digit running direction switching valve, and is interposed between the turning direction switching valve 26 and the left running motor 5. Note that the force direction switching for the arm, the square 25, the turning direction switching valve 26, and the right running direction switching valve 27 are connected in parallel to the second hydraulic pump 24. The second hydraulic pump 24 mentioned above
, directional control valves 25, 2b, 27. Another independent hydraulic rotating vessel is formed by the arm cylinder 12, the k-turn motor 3, and the left foot pedal 5.

However, the conventional hydraulic circuit configured as described above has the following problems. In other words, ■°When operating the arm while traveling, the arm directional switching valve 25 and the right running directional switching valve 27 are connected in parallel, so compared to the left running directional switching valve 27 side. Pressure oil tends to flow toward the directional control valves 2 and 5 for the arms with light loads, and as a result, the operation of the left truck tends to be slower than that of the right truck, making it impossible for heavy vehicles to travel on mountain roads. Conventionally, a combined arm/travel simulation has been performed when a wetland emerges, etc., but if the left and right trunks spin, sufficient force cannot be obtained from the arms.

■ When performing a turning operation while traveling, since the turning/drawing direction switching valve 26 and the right running direction switching valve 27 are connected in parallel, it is easier to turn than the right running direction switching valve 27. Pressure oil tends to flow toward the direction switching valve 26, which is slower than the operation of the sticky left trunk or the stone trunk, making it impossible for the vehicle to travel straight. Also, when the running load is heavy, there is insufficient pressure to support turning.
It is difficult to perform the rotation ig1 operation.

■ When operating the packet while driving, the packet directional control valves 2 and 1 and the right-hand directional control valve 23 are connected in parallel, so the load is lower than that on the right-hand directional control valve 23 side. Pressure oil tends to flow toward the light packet directional control valve 21, and as a result, the operation of the right trunk becomes slower than that of the left trunk, making it impossible for a heavy object to travel straight ahead.

■ When operating the boom while traveling, the boom directional switching valve 22 and the right foot directional switching valve 23 are connected in parallel, so the boom directional switching valve 22 has enough power to raise the boom. The present invention has been made in view of the above problems in the prior art, and its purpose is to prevent the boom from rising due to insufficient pressure oil being supplied. Activate the actuator of the village.
The purpose is to provide the hydraulic recovery machine of the recovery machine to flames.

To achieve this objective, the present invention supplies pressure oil to the actuator? JJ [hydraulic pump glue, first
10,000 travel directional valves are connected to the left and right hydraulic pumps, and a swing directional valve, an arm directional valve, and an arm directional valve are connected to the second hydraulic pump. Connect at least one of the
The driving directional control valve on the Ip side is connected in tandem, and the input boat of the other driving directional control valve and the second upstream directional control valve are connected in tandem.
and the discharge oil supply circuit of the oil volume pump through a pressure regulating means, and the input port of the one retraction directional control valve and the input port of the other traveling directional control valve are connected to each other.

! The configuration is connected by blue.

Hereinafter, the hydraulic circuit of the civil engineering/construction machine of the present invention will be explained with reference to the drawings. 14g, Figure 4 shows the first opening of the present invention.
The rotation diagram of IJ, without showing the structure, is the second husband btx of the present invention. This is a diagram of the composition of 'i. In addition, in these attacks, MiJ mentioned fc, m51 figure or the third attack, the attack and the dent! The phase is indicated by a 10"-mark.

Directional switching valve 2 for vacunt that operates the cylinder 13
-1, the first boom direction switching 7P28 that operates the boom cylinder 11, and the right travel direction switching valve 23 that fully operates the right travel motor 7 are connected in parallel to the first hydraulic pump 20. be. 1) i-side directional control valve 26 for operating the gl motor 3; and a second arm directional control valve for operating the boom cylinder 11;
9, the arm directional switching valve 25 that operates the arm cylinder 12 and the hydraulic pump 24 of program 2 are connected in parallel, and the left running directional switching valve 27 that operates the left running cloud 5 is connected in parallel to the arm directional switching valve 25 that operates the arm cylinder 12. It is connected in tandem downstream of the switching valve 25. Then, the input port of the left travel direction switching valve 27 and the discharge oil supply circuit of the second r...
For example, the pressure adjustment circuit 34 is made up of waves by a circuit 33, which is a light source. In addition, the input port of the direction cutting car 23 for stone fixing and the input port of the left credit force direction cutting machine 27 are connected through the connection chamber 3o to set the stone. Note that the load check 31c and load check 31a described above,
Reference numeral 31b is a 7ζ type provided to prevent discharged oil from being quenched.

Like this Di r,! The action in the hydraulic circuit is as follows.

7. When operating the side direction switching valve 23 and 27 independently, it is the same as the normal outer layer 1. In other words, Ki 1-7
The oil discharged from the soup stock pump 2'O is supplied from the parallel circuit through the load check 31a to the stone traveling direction changeover 023, and the oil discharged from the second hydraulic pump 24 is supplied to the load check 31b from the parallel circuit. The air is supplied to the left travel direction switching valve 27.

In addition, when operating the arm direction switching valve 25 while driving with the ladle side direction switching (Y valve 23, 27 operated),
The pressure oil of the first 71+ (pressure pump 2o) is sent to the right travel directional control valve 23 to the stone 71: row motor 7゛, which
drive -The second hydraulic pump 24 is damaged by the
+ indicates arm side [cutback: 9p2. s purple to arm cylinder 12 91. iq areru. At the same time, a portion of the pressure oil from the hydraulic system node z4 of m12 is also supplied to the traveling direction changeover valve 27 through the circuit 33. A part of the pressure oil from the second hydraulic pump 24 flows into the arm cylinder 12 as described above, and the oil is transferred to the left travel direction switching valve 2.
7, the amount of oil to this left-hand direction switching valve '27 is insufficient or insufficient, but the pressure oil of the first hydraulic pump 2o is also supplied to the left-hand direction change-over valve 27 by the cover pipe 30. Therefore, the left foot motor 5 can be driven in rotation with the right travel motor 7. Here, the oil supply circuits for the left leg motor 5 and the right running motor 7 are connected in parallel through a connection pipe 3o, and it seems that the amount of oil does not necessarily flow every minute. The crawler itself, which is a running body, has an undesirable straight-line ability, which hinders self-propulsion. In this way, the oil discharged from the hydraulic pump 24 of the arm cylinder 12VC can be supplied with priority, and the oil discharged from the first hydraulic pump 2o and the oil discharged from the first hydraulic pump 2o can still be supplied to the EEi row motor 5 and the right travel motor 7. Since the remaining discharge oil from the second hydraulic pump 24 can be supplied, I! ``Without impairing malignancy''
In addition, sufficient power can be secured in the arm even when escaping from a wetland by combining the arm and travel joint.

Furthermore, when operating the swing direction changeover valve 26 while operating the travel direction changeover valves 23 and 27, the oil discharged from the second hydraulic pump 24 is transferred to the swing direction changeover valve 26. Although the oil supply to the left running motor 5 is insufficient, the connection pipe 3o allows the discharge oil of the mud 1 (γ1 (1 pressure pump 20) to be Right travel motor 7
Since JK is supplied, it is possible to maintain the progression +1-. .

i fr travel direction switching valve 23.・When operating the packet directional switching valve 21 while operating the packet directional switching valve 27, the pressure oil of the first hydraulic pump 20 is transferred to the packet directional switching valve 21 and the right travel directional switching valve 23. It is then supplied to the packet cylinder 13 and the right travel motor 7. Therefore, the Fl-oil supplied to right travel motor 7r4 is reduced.
However, the second i which is supplying pressure oil to the left travel motor 5
l! Since sufficient pressure oil is supplied from the pressure pump 24 to the right travel motor 7 via the #112 blower 30 (r), straight travel can be maintained.

In addition, when operating the boom side direction switching a 2d, 29τ while traveling by operating the travel direction switching valves 23, 27, the pressure oil from the second hydraulic bone pump 24 is restricted by the throttle 34. Therefore, the flow to the left fixed bamboo side direction Kirimata valve 27 is <<,
This pressure oil is supplied to the boom cylinder 11 via the second boom side directional control valve 29, and the pressure oil from the first hydraulic pump 20 passes through the travel directional control valves 23' and 27 for right travel. Since it is supplied to the motor 7 and the travel motor 5, the boom can be reliably raised even if the travel distance is low.

The second embodiment shown in FIG. 5 is basically the same in configuration as the first embodiment shown in No. 4M, but the difference is that the input boat of the right-hand travel directional control valve 23 and h: for travel. Direction - Houben 2
An opening/closing fP32 is provided in the middle of the connecting pipe 30 that connects the input boat 7 and e6. This on-off valve 32 may be operated manually according to the Ministry of Construction, or may be operated by pedal operation using a hand or foot. In the second Oshima spear constructed in this way, the left travel motor 5 and the right travel motor 7 can be operated separately by operating the on-off valve 32 as appropriate.
Therefore, if only the driving operation is carried out in a semi-uniform manner, it becomes impossible to maintain straight running, especially on sloping terrain.

゛ Naojo 6 members first. In the second 1J^' example, there is a directional switching valve 21 for packets, a directional switching valve 28 for the first boom, and a directional switching valve 23 for right travel.
Although this is connected in parallel to the first one-way pump 20, it is also possible to connect only the packet directional switching valves 21 in tandem instead of this. Even in this case, the same effect as above can be obtained.

Further, in the above-mentioned oil and light, the pressure adjustment means interposed in the circuit 33 is provided with a relief valve 34, but a relief valve may be provided in place of this ft.934.

Civil engineering of all inventions, Meimei 61. The hydraulic circuit of the machine is
Connect the indicated one of the left and right running directional control valves to the first valve, as shown in Figure 2,
The turning side direction is a chivalry masu, the arm force is also a grudge masu,
Connect at least one C of the Mando 9J Kaisho for the boom, and connect the other traveling direction switching valve in tandem 1 downstream of it.
However, the input boat of the other travel directional control valve and the discharge of the second hydraulic pump located upstream? A configuration in which the self-supply circuit is connected to the pressure-receiving means through a bush, and the input boat of one running directional control valve and the input boat of the other running directional control valve are connected by a drop pipe. In the event that the actuator is actuated during the car C), the left drive motor and the H off from the first or second hydraulic pump via the connection i-. It is possible to uniformly supply the right running motor to the right running motor, and it is possible to obtain uniform running force to the left and right tracks of the outer body fff, which makes it possible to operate various actuators evenly, and to drive straight. This has the effect of reducing your driving time to 1J.

[Brief explanation of the drawing]

The first problem is civil engineering, which is the object of the present invention.
J oia diagram, the second box is the first prisoner's ¥-1, the third box is the subordinate O, a circuit diagram showing an example of the hydraulic Lg circuit of the civil engineering / girl construction equipment - the fourth and 1 is +: A circuit diagram showing the first embodiment of the hydraulic circuit for the civil engineering, construction and machinery of the invention, Figure 5 is the civil engineering -
・Illustrated in Figure 1 showing an example of the hydraulic circuit of the rainbow 6 "Hydraulic circuit 2". 1...Swivel body, 2...Rotating body, 3...Swivel motor, 4...・Left trunk, 5...Left running motor, 6...
・Right truck, 7...Right travel motor, 8...Boom, 9...Arm, 11...Boom cylinder, 12.
・・Arm cylinder, 20,・, U-1 hydraulic pump,
23... Directional switching valve for right travel, 24... Second hydraulic pump, 25... Directional switching valve for arm, 26... Directional switching valve for turning, 27... Left traveling direction switching Screw valve, 28
...First boom directional switching valve, 29...-Second arm directional switching valve, 30... Connection pipe, 31a. 31b, 3]c...Load check, 32...l[
Valve, 33...Circuit, ;34...Carp (H-force 1.1
^: Adjustment means). Figure 1 0 Figure 2

Claims (1)

[Claims] 1. A plurality of hydraulic pumps, a plurality of actuators driven by pressure oil from these hydraulic pumps, and a direction and a flow rate of the pressure oil flowing from the hydraulic pumps to the actuators. In a hydraulic circuit for a civil engineering/construction machine equipped with a plurality of directional switching valves for controlling Connect the pump to at least one of a directional switching valve for swing, a directional switching valve for arm, and a directional switching valve for boom, and connect the other directional switching valve for traveling in tandem downstream thereof, The input boat of the switching valve and the discharge old supply circuit of the second hydraulic pump located upstream are connected via a pressure regulating means, and the human-powered boat of one of the traveling directional switching valves and the upper me Hydraulic (9) path of civil engineering/MFI machinery whose sexual characteristics are the input boat of the travel directional control valve and the fact that it was boxed by the number code pile officer. 2. The hydraulic circuit for civil engineering/construction machinery according to claim 1, wherein the pressure vI4 adjusting means is a throttle. 3. The hydraulic circuit for civil engineering and construction machinery as set forth in claim 1, wherein the pressure regulating means is a relief valve. 4. Civil engineering/41ff according to claim 2 or 3, characterized in that an on-off valve is provided in the middle of the connecting pipe.
Machine hydraulic circuit.