JPS62174423A - Oil-pressure driver for civil construction machine - Google Patents

Abstract

PURPOSE:To permit combined operation of a traveling motor with other actuators and also combined operation of the other actuators with each other without the operation of the traveling motor to be performed by reducing the opening degree of a direction switch valve. CONSTITUTION:In the combined operation of traveling motors 56 and 58 with other actuators, the opening degree of direction switch valves 32 and 38 for traveling or direction switch valves 24, 28, 44, and 45 for other actuators is reduced by a controller 200, thereby permitting combined operations of the motors 56 and 58 with other actuators to be performed. In the combined operations of other actuators with each other without the operation of the motors 56 and 58, the opening degree of the direction switch valve for any of the actuators is reduced by the controller 200 in such a way as to effect combined operation of the actuators.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> Seikan FIA relates to a hydraulic drive device installed in a civil engineering construction machine such as a hydraulic excavator, and particularly relates to a hydraulic drive device with excellent compound operation and performance.

<Prior art> As this type of hydraulic drive device, for example, Japanese Patent Application Laid-Open No. 58-14
There is one described in Japanese Patent No. 6632.

This conventional example has two hydraulic circuits, each of which includes a hydraulic pump, a travel directional valve, a swing directional valve, a boom directional valve, an arm directional valve, and a packet directional valve. A valve group including a switching valve is provided, and each directional switching valve of the valve group is connected to a corresponding actuator such as a travel motor, a swing motor, a boom cylinder, an arm cylinder, a packet cylinder, or the like. In order to perform compound drive of the travel motor and other actuators, independent drive of each of the other actuators by two hydraulic pumps, and double metal ``EV'' between the other actuators, a boom cylinder, an arm cylinder, and a packet cylinder are used. A plurality of directional control valves are connected to each of the hydraulic pumps, etc.In addition, in order to perform combined operation of the boom and arm without traveling, a directional control valve for the boom is connected to one hydraulic pump via a bypass line. The valve and the arm directional control valve are connected in parallel.

<Problems to be Solved by the Invention> By the way, in the hydraulic drive device configured as described above, there are many directional control valves connected to actuators such as boom cylinders, arm cylinders, and packet cylinders. Manufacturing costs tend to be high. In addition, since the boom cylinder and arm cylinder are connected in parallel to one hydraulic pump, when performing two combined operations of the boom and arm, the operation must be performed according to changes in the load pressure of each of the boom and arm. This causes unintended speed changes in the boom and arm, making it difficult to improve operability.

The present invention has been made in view of the actual situation in the prior art, and its purpose +S is achieved by providing a relatively large number of directional control valves in the combined drive of the travel motor and other actuators. The object of the present invention is to provide a hydraulic drive device for civil engineering and construction machinery that can perform two combined operations of a boom and an arm without being influenced by other load pressures.

Means for Solving Problems> In order to achieve this objective, the present invention includes a first hydraulic circuit and a second hydraulic circuit that drive a plurality of actuators, the first hydraulic circuit: The second hydraulic circuit has a first hydraulic pump and a first valve group Z including a plurality of directional valves Y each controlling the flow of pressure oil from the first hydraulic pump to a corresponding actuator. , a second hydraulic pump, and a second valve group including a plurality of directional control valves each controlling the flow of pressure oil from the hydraulic pump of this wc2 to the corresponding actuator, and the plurality of actuators are at least left and right. an operation command means, which includes a traveling actuator, a boom actuator, an arm actuator, and a swing actuator, and is provided corresponding to the actuator and outputs an operation command No. 1a for driving these actuators; The control means performs predetermined calculation and discrimination processing according to the operation command signal outputted from the operation command means, and outputs an operation command signal to the directional control valve according to the result. Providing a passage connecting the discharge passage of the pump and the discharge passage of the second hydraulic pump,
A valve means capable of communicating and shutting off the passage is provided in the passage,
The first valve group includes a first travel direction switching valve that controls the flow of pressure oil to one of the left and right travel actuators, and an arm direction switching valve that controls the flow of pressure oil to the arm actuator. A switching valve, a swing direction switching valve for controlling the flow of pressure oil to the swing actuator, and a first traveling direction switching valve, an arm direction switching valve,
The swing direction switching valve is connected in parallel to the first hydraulic pump, and the second valve group is a second valve group that controls the flow of pressure oil to the other of the left and right travel actuators.
a traveling directional switching valve; and a boom directional switching valve that controls the flow of pressure oil to the boom actuator; connected in parallel to the pump, the control means includes a valve means, a first travel directional valve, a second travel directional valve, a swing directional valve, a boom directional valve,
Output means for outputting signals for respectively operating the arm directional control valves.

A first operation command signal for driving a predetermined first actuator among the plurality of actuators is being output, and a predetermined second actuator Z among the plurality of actuators is driven. and a limiting means for limiting the operation command signal given to the directional control valve corresponding to the first actuator according to a predetermined functional relationship when the second operation command signal is output.

Since the present invention is configured as described above, when the travel motor and other actuators are combinedly driven, the restriction means of the control means controls the travel direction switching valve and the direction switching valves for the other seven actuators. By narrowing the opening of either one of the directional control valves, it is possible to implement combined drive between the travel motor and other actuators.In addition, in the case of combined drive between other actuators that does not involve driving the travel motor, the limiting means is used. By restricting the opening degree of the directional control valve for either actuator, it is possible to perform compound drive between the actuators, and basically by providing one directional control valve for one actuator, these compound drives can be performed. It is now possible to do it. Furthermore, since the arm cylinder 'lt is provided in the first valve group connected to the first hydraulic pump, and the boom cylinder 'lt is provided in the second valve group connected to the second hydraulic pump, these booms The cylinder and the arm cylinder can be driven without being influenced by other load pressures.

<Example> Hereinafter, a hydraulic drive system for civil engineering construction machinery according to the present invention will be explained based on the drawings. FIG. 1 is a circuit diagram showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram illustrating a function table provided in a control means constituting the embodiment shown in FIG.

In FIG. 1, 4 is a first hydraulic pump, and 5 is this first hydraulic pump.
a regulator that controls the discharge volume of the hydraulic pump 4;
6 is a second hydraulic pump, 7 is this second hydraulic pump 6
This is a regulator that controls the discharge volume. 48 is a swing motor; 24 is a link from the first hydraulic pump 4 to the swing motor 4;
8 is a swing direction switching valve that controls the flow of pressure oil supplied to the arm cylinder 52; 28 is an arm directional switching valve that controls the flow of pressure oil that is supplied from the first hydraulic pump 4 to the arm cylinder 52; 56 is a travel motor, for example, a left travel motor; 32 is a valve from the first hydraulic pump 4 to the left travel motor 5;
This is a left-hand travel directional switching valve that controls the flow of pressure oil supplied to the left-hand drive. The above-mentioned swing direction switching valve 24, arm direction switching valve 28, and left travel direction switching valve 32 are each connected in parallel to the first hydraulic pump 4; The connecting boat is a neutral block. In addition, these directional control valves 24°28
．． 32 constitutes a first valve group, and this first valve group and the first hydraulic pump 4 constitute a first hydraulic circuit.

In particular, the above-mentioned swing direction switching valve 24 and swing motor 48
．． and arm directional control valve 28 and arm cylinder 52
This means that they are almost integrally connected directly without any intervening hydraulic hoses.

58 is a right travel motor, 38 is a right travel direction switching valve that controls the flow of pressure oil supplied from the second hydraulic pump 6 to the right travel motor 58, and 50 is a first boom cylinder (for right travel).
, 44 is a boom right direction switching valve that controls the flow of pressure oil supplied from the second hydraulic pump 6 to the first boom cylinder 50, 51 is a second boom cylinder (Ishikawa), and 45 is a second boom cylinder. a boom rock directional switching valve that controls the flow of pressure oil supplied from the hydraulic pump 6 to the second boom cylinder 51;
54 is a packet cylinder, and 42 is a flow of pressure oil supplied from the second hydraulic pump 6 to the packet cylinder 54.
This is a packet directional switching valve that controls 1tlJ. The above-mentioned right travel direction switching valve 38 and boom main direction switching valve 44.
The boom right directional control valve 45 and the packet directional control valve 42 are each connected in parallel to the second hydraulic pump 6, and the connection ports connected to the respective hydraulic pumps 6 serve as neutral blocks. ing. Further, these directional control valves 38, 44, 45, 42 constitute a second valve group, and this second valve group and the second hydraulic pump 6 constitute a second hydraulic circuit. There is.

In particular, the above-mentioned boom left directional switching valve 44, first boom cylinder 50, and boom useful directional switching valve 45
The second boom cylinder 51, the packet directional switching valve 42, and the packet cylinder 54 are each connected almost integrally without intervening a hydraulic hose.

121 is a discharge passage of the first hydraulic pump 4, 122 is a discharge passage of the second hydraulic pump 6, and 123 is a discharge passage of these discharge passages 121, 122'P! : A valve means, for example, an on-off valve 120, is provided in the middle of this passage 123 to connect the passage 123 and to shut it off. Note that the ends of the discharge channels 121 and 122 and the ends of the return channels 124 and 125 connected to the tank are closed off by blind plates.

1) 0 is the left travel motor 56, right travel motor 58, swing motor 48, arm cylinder 52, first boom'/su 7
The operation command means, that is, the command device 200 outputs the operation command signal to drive each actuator Z such as the cylinder 50, the second boom cylinder 51, and the packet cylinder 54, and performs a predetermined calculation 1 determination process according to the operation command signal, Depending on the result, the directional control valve 24.28, 32, 38, 44
45.42 and an output means for outputting an operation command signal to the drive section of the on-off valve 120.

As shown in FIG. 2, this control means 200 includes a second actuator, for example a first actuator, which is output from the command device 1)0. A first function table 130 showing the correlation between the operation command signal X1 for driving the second boom cylinder 50, 51 and the coefficient; A second function table 131 showing the correlation between X2 and the target operation command signal Y2, and a coefficient output from the first function table 130 and a target operation command signal Y2 output from the second function table 131. Multiply the left and right travel motors 56,5
8Y [multiplier 13 that outputs operating command signal Y2”k to move
2 are provided. Note that the first relationship table 130
A relationship is set in which the coefficient decreases as the operation command signal X1 increases, and the second function table 1
31 is set such that the target operation command signal Y2 increases as the operation command signal X2 increases, and these first function table 130, second function table 131, and multiplier 132 are as follows. It constitutes a limiting means for limiting the operation command signal Y2' to be smaller than the target operation command signal Y2χ.

In the embodiment configured in this way, for example, when performing a combined operation of traveling and raising the boom, the command device! !
1) An operation command signal X1 from 0 to the 1st #2 boom 50, 51 is output to the control means 200, and an operation command signal X2 from the command device 1) 0 to the left and right travel motors 56, 58 is output. It is output to the control means 200. In response to this, the control means 200 outputs an operation command signal sound to the drive section of the on-off valve 120 to open the passage 123'! The operation command signal Y is outputted to the respective drive parts of the boom left direction switching valve 44 and the boom rock direction switching valve 45, and the first function table 130 shown in FIG. Second
The coefficient K corresponding to the operation command signal X related to the boom cylinder 50.51 is selected, and the operation command signal X related to the left and right travel motors 56.58 is selected based on the second function table 131.
Select target operation command signal Y27 according to 2, and multiplier 13
Multiply these coefficients by 2 by the target operation command signal Y21,
Obtained operation command signal Y2'Y left travel direction switching valve 32
, is output to the drive section of the right travel direction switching valve 38.

As a result, the value of the operation command signal Y2' becomes smaller than the value of the target operation command signal Y2, that is, the opening degrees of the left-hand travel direction switching valve 32 and the right-hand travel direction change-over valve 38 are narrowed down, and the left-right travel direction change valve 38 is narrowed down. The king on the motor 56.5B side rises, and boom raising work, which requires relatively large pressure, can be performed while traveling.

Further, when performing a combined operation of the boom and arm that does not involve traveling, the control means 200 does not output an operation command signal to the drive section of the on-off valve 120, so the passage 123 is kept cut off, and the control means 200 The drive section of the arm direction switching valve 28 and the boom left direction switching valve 44.
An operation command signal is output to the drive section of the boom right direction switching valve 45.

The oil discharged from the first hydraulic pump 4 is transferred to the arm directional control valve 28.
The oil discharged from the second hydraulic pump 6 is supplied to the arm cylinder 52 through the boom right direction switching valve 44 and the boom right direction switching valve 45 to the first and second boom cylinders 50 and 51. and can drive each of them.

In the embodiment with grooves as described above, by basically providing one directional switching valve for each actuator, it is possible to drive the left and right travel motors in combination with other actuators, or to drive the other actuators independently. Drive, combined drive with other actuators! It can be done easily and the manufacturing cost can be reduced.

Furthermore, when performing combined operations of the boom and arm, each can be driven independently without being affected by other load pressures. Second boom cylinder 44, 45
, excellent operability can be obtained without causing a change in the operating speed of the arm cylinder 52.

Furthermore, by appropriately setting the function relationship between the first function table 130 and the second function table 131 shown in FIG. , sudden speed changes χ of the left and right boom directional control valves 44 and 45 can be prevented, thereby providing excellent operability.

Note that in the above embodiment, the first function table 13
0, the second function table 131, and the multiplier 132, during traveling, that is, while the left and right travel motors 56 and 58, which are the first actuators, are being driven, the boom raising operation, that is, the first.0, which is the second actuator, is performed. When driving the second boom cylinder 50.51, the operation command signal Y2 is output to the left/right travel direction switching valve 32.38.
However, the present invention is not limited to this, and the first actuator is the left and right travel motor 56,
58, and the second actuator is one of the first . The present invention can also be applied to either one of the second boom cylinders 50 and '51. Further, the above-mentioned first actuator is the arm cylinder 52, and the above-mentioned second actuator is the arm cylinder 52.
The actuator may be the swing motor 48, and in this case, for example, the arm can be lowered during the swing by increasing the pressure on the arm side by narrowing the opening degree of the arm directional control valve 28. Also, depending on the type of work, the second actuator described above may be driven by the left and right travel motors 56, 5.
8, the first actuator is the swing motor 48, the first actuator is the swing motor 48, and the first actuator is the swing motor 48. Second boom cylinders 44, 45. It may also be an arm cylinder 52 or a packet cylinder 54.

FIG. 3 is a circuit diagram showing another embodiment of the present invention. In the embodiment shown in FIG. 1 described above, each directional control valve 24°28.
, 45, 42Y neutral block, but in another embodiment shown in FIG.
2. Directional switching valve 38 for right travel, directional switching valve 44 for boom
The a1 packet switching valves 42 are each set to a center bypass type, and have a structure that can be adapted to the on-off valve 120a'g center bypass provided in the passage 123. The first arm directional control valve 44a has two arm directional control valves 44a. It is configured to drive a second boom cylinder 50.51. Control means 2
The function table etc. provided in 00 are similar to those shown in FIG. 2, for example.

Even in the embodiment configured in this manner, the same operation and effect as the embodiment shown in FIG. 1 described above can be achieved.

<Effects of the Invention> Since the hydraulic circuit of the civil engineering construction machine of the present invention is configured as described above, the combined drive of the travel motor and other actuators can be achieved by providing a smaller number of directional control valves than in the past. This can be realized by doing this, and the manufacturing cost can be lower than in the past. In addition, the combined two movements of the boom and arm can be realized without being influenced by each other (other load pressures), and there is no unintended speed change Z of the boom or arm caused by the operator, as in the past. Depending on the setting of the limiting means of the control means, it is possible to prevent sudden changes in the operating speed of each actuator during compound drive, and as a result, superior operability compared to the conventional art can be obtained.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the hydraulic drive system for civil engineering construction machinery according to the present invention, and FIG. 2 is an embodiment of the hydraulic drive system shown in FIG. 1. FIG. 3 is an explanatory diagram showing a function table provided in the constituting control means, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. 4...First hydraulic pump, 6. Old...Second hydraulic pump, 24...Swivel directional control valve, 28.
...7-Directional switching valve for boom, 32... Directional switching valve for left running, 38... Directional switching valve for right running, 44... Own boom left direction Switching valve, 44a/old/
・Boom directional switching valve, 45...Boom useful directional switching valve, 48...Swivel motor, 50...
...First boom cylinder, 51...Second boom cylinder, 52...Arm cylinder, 54
...Packet cylinder, 56...Left travel motor, 58...Right travel motor, 1)0...
group/command device, 120a, 120...on/off valve,
121.122...Group・Discharge flow path% 123...Group・
Passage, 130... River, first function table, 131...
. . . second function table, 132 . . . multiplier, 200 . . . control means. '-''-ri... , : ゛, mini agent patent attorney Kenjibu Takeshi's, Hl, i Figure 1 Figure 2 / 30: Rin's B0 number tape 131: Tomi 2's Function 'Qi7-)L 132: Multiplier

Claims (4)

[Claims] (1) The first hydraulic circuit includes a first hydraulic circuit and a second hydraulic circuit that drive a plurality of actuators, and the first hydraulic circuit includes:
a first valve group including a first hydraulic pump and a plurality of directional valves each controlling the flow of pressure oil from the first hydraulic pump to a corresponding actuator; , a second hydraulic pump, and a second valve group including a plurality of directional valves each controlling the flow of pressure oil from the second hydraulic pump to a corresponding actuator, the plurality of actuators having at least an operation command means that includes left and right traveling actuators, a boom actuator, an arm actuator, and a rotation actuator, and is provided corresponding to the actuator and outputs an operation command signal to drive these actuators; , a control means for performing predetermined calculation and discrimination processing according to the operation command signal output from the operation command means, and outputting an operation command signal to the directional control valve according to the result. In the hydraulic drive device, a passage is provided that connects the discharge passage of the first hydraulic pump and the discharge passage of the second hydraulic pump, and the passage can be communicated or disconnected in the passage. The first valve group includes a first travel direction switching valve that controls the flow of pressure oil to one of the left and right travel actuators, and a first travel directional control valve that controls the flow of pressure oil to one of the left and right travel actuators, and a first travel directional control valve that controls the flow of pressure oil to one of the left and right travel actuators. an arm directional switching valve that controls the flow of oil; and a swinging directional switching valve that controls the flow of pressure oil to the swinging actuator; The directional control valve and the swing directional control valve are connected in parallel to the first hydraulic pump, and the second valve group supplies pressure oil to the other of the left and right travel actuators. the second to control the flow of
a traveling directional switching valve, and a boom directional switching valve that controls the flow of pressure oil to the boom actuator,
Moreover, the second travel directional valve and the boom directional valve are connected in parallel to the second hydraulic pump, and the control means is connected to the valve means and the first travel directional valve. , a second driving direction switching valve, a turning direction switching valve,
Output means for outputting signals for respectively operating the boom directional switching valve and the arm directional switching valve; and a first operation command signal for driving a predetermined first actuator of the plurality of actuators. When a second operation command signal for driving a predetermined second actuator among the plurality of actuators is output in a state where 1. A hydraulic drive device for civil engineering and construction machinery, comprising a limiting means for limiting an operation command signal given to a directional control valve corresponding to an actuator. (2) The first actuator is at least one of the first travel actuator and the second travel actuator, and the second actuator is the first travel actuator and the second travel actuator. at least one of the other plurality of actuators excluding
A hydraulic drive system for civil engineering and construction machinery according to claim (1). (3) The hydraulic drive system for civil engineering and construction machinery as set forth in claim (1), wherein the first actuator is an arm actuator and the second actuator is a swing actuator. (4) The first actuator is at least one of a plurality of actuators excluding the first travel actuator and the second travel actuator, and the second actuator is the first travel actuator and the second travel actuator. The hydraulic drive device for civil engineering and construction machinery according to claim (1), wherein the hydraulic drive device is at least one of the two traveling actuators.