JP2003247506A - Valve system and fluid pressure circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve system capable of directly performing pilot operations of a main control valve and precisely grasping an interlocked operating state without using a pressure switch on a pressure sensor. <P>SOLUTION: An oil pressure remote-control valve 24 produces a pilot pressure to the main control valve 23 of a hydraulic circuit in proportion to control input amount by a manipulation body 22. A control input amount detection device 26, which outputs an electric signal corresponding to control input amount by a lever to a controller 25 for controlling the hydraulic circuit by electrically detecting the control input amount of the manipulation body 22, is arranged on an upper portion of the oil pressure remote-control valve 24. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manually operated valve device and a fluid pressure circuit using this valve device.

[0002]

2. Description of the Related Art As shown in FIG. 4, a hydraulic excavator as a construction machine includes an undercarriage 11 provided with a traveling motor.
The upper revolving structure that can be revolved by the revolving motor of the revolving unit 12.
A boom 14 of a front working machine is rotatably supported by a boom cylinder 15 on the upper swing body 13 so as to be vertically rotatable. A stick 16 is attached to the tip of the boom 14 and an inward / outward direction is applied by a stick cylinder 17. The stick 18 has a bucket 18 rotatably supported at its tip end by a bucket cylinder 19 so as to be rotatable in the opening / closing direction.

In such a hydraulic excavator, the operation of actuators such as a traveling motor, a swing motor, a boom cylinder 15, a stick cylinder 17 and a bucket cylinder 19 is controlled by a movable valve element of a pilot operated main control valve. There is a running stem, a turning stem,
Boom stems, stick stems, and bucket stems, each of which is a lever-operated or pedal-operated hydraulic pilot control valve (hereinafter,
The pilot control valve is generally called a "remote control valve").

In this case, in order to detect an interlocking operation state such as boom raising + turning, a pressure switch or pressure sensor is mounted in the circuit on the pilot secondary pressure side generated from the hydraulic remote control valve, and the operating lever is operated by these. The amount of operation of is detected indirectly, or a hydraulic logic circuit is installed in the main control valve, and when the interlocking operation state is met, pressure is generated and the hydraulic circuit is switched to adapt to the interlocking operation state. Are doing

In a machine equipped with an electric operation lever that outputs an electric signal corresponding to the lever operation amount, it is easy to detect the interlocking operation state from the electric signal,
An arithmetic circuit for arithmetically processing this signal and driving the main control valve is required in the controller.

[0006]

As described above, when the conventional hydraulic remote control valve is used, the pressure switch, the pressure sensor, and the pressure sensor for detecting the interlocking operation state and switching the hydraulic circuit,
It is necessary to use a hydraulic logic circuit, and for machines equipped with electric operation levers, a controller that controls the main control valve with a control signal that processes the detection signal of the interlocked operation state is required, which makes the system complicated. However, there is a problem in that it is difficult to troubleshoot to investigate the cause of the trouble.

The present invention has been made in view of the above points, and a valve device which can directly pilot the main control valve and accurately grasp the interlocking operation state without using a pressure switch or a pressure sensor, A fluid pressure circuit using a valve device is provided.

[0008]

According to a first aspect of the present invention, there is provided a pilot control for outputting a pilot pressure to an operating body and a pilot operated main control valve of a fluid pressure circuit according to an operation amount of the operating body. A pilot control valve, which is a valve device including a valve and an operation amount detection device that electrically detects an operation amount of an operating body and outputs an electric signal corresponding to the operation amount to a controller for controlling a fluid pressure circuit. The pilot pressure output from the main control valve can be directly pilot-operated according to the operation amount of the operating body, and the operation amount of the operating body can be directly detected by the operation amount detecting device to the controller for controlling the fluid pressure circuit. Since it outputs an electric signal according to the operation amount, pressure detection means for detecting the interlocked operation state of conventional pressure switches and pressure sensors is used. Without providing the body pressure circuit in, the electric signal output from the operation amount detecting apparatus, the controller can accurately determine the synchronous operation state.

According to a second aspect of the invention, in the valve device according to the first aspect, the operating body is provided so as to be movable in any direction, and the pilot control valve is operated by the operating body operated in one direction. One spool that outputs a pilot pressure to one movable valve body of the main control valve that is pushed and moved to another movable valve body of the main control valve that is pushed and moved by an operating body that is operated in the other direction that intersects with one direction. The operation amount detection device, which has another spool for outputting pilot pressure, outputs one signal according to the operation amount in one direction, and one operation amount sensor for outputting a signal according to the operation amount in one direction. The other operation amount sensor is provided, and one spool and the other spool can be interlocked with one operation body, and the operation amount of each of these spools is It can accurately grasp the interlock operating state is respectively detected by the operation amount sensor.

According to a third aspect of the invention, in the valve device according to the second aspect, the operating body is rotatably provided in any direction, and one operation amount sensor is a rotating angle in one direction. Is a valve device that is a single angle sensor that outputs a signal in accordance with the above, and the other operation amount sensor is a valve device that is another angle sensor that outputs a signal in accordance with the rotation angle in the other direction. Can be rotated in the middle between one direction and the other direction to easily operate the one spool and the other spool, and the operation amount of each spool can be adjusted by the one angle sensor and the other angle sensor, respectively. You can easily detect and accurately know the linked operation status.

According to a fourth aspect of the present invention, a plurality of movable valve bodies of the main control valve for controlling the direction of the fluid discharged from the pump and supplying the fluid to a plurality of actuators, and a plurality of movable valve bodies of the operating body are provided. A valve device that performs pilot operation with a pilot pressure according to the operation amount and that outputs an electrical signal according to the operation amount of the operating body, and determines the interlocking operation state from the electrical signal output from the valve device, and responds to the interlocking operation state Fluid pressure circuit that includes a controller that outputs a control signal and a solenoid proportional valve that outputs a pilot control pressure according to the control signal from the controller to the movable valve body to change the movable valve body according to an interlocking operation state. The pilot pressure output from the valve device directly pilots the movable valve element of the main control valve according to the operation amount of the operating element. The delay caused by the calculation time in the controller can be prevented, and the controller determines the interlocking operation state by the electric signal output from the valve device according to the operation amount of the operating body, and controls according to the interlocking operation state. A signal is output to the solenoid proportional valve, and a pilot control pressure corresponding to the control signal is output from the solenoid proportional valve to the movable valve body to change the movable valve body according to the interlocking operation state. If an abnormality occurs in the, the interlocking operability may be impaired, but the basic function of pilot-operating the movable valve element of the main control valve by the valve device is not impaired.

According to a fifth aspect of the present invention, in the fluid pressure circuit according to the fourth aspect, the controller and the solenoid proportional valve receive a fluid supplied from a common pump, and a specific movable valve element and another movable valve element. Among them, the pilot pressure acting on a specific movable valve element is controlled to return the specific movable valve element to the direction of the neutral position according to the operation amount for another movable valve element. Since the flow rate of the fluid supplied to the corresponding actuator via the movable valve body is suppressed, the flow rate of the fluid supplied from the common pump to the corresponding actuator via the other movable valve body can be secured.

According to a sixth aspect of the invention, in the fluid pressure circuit according to the fourth or fifth aspect, the flow rate of the fluid supplied to one movable valve body is changed to the flow rate of the fluid supplied to another movable valve body. On the other hand, a priority valve that prioritizes the flow rate supplied to another movable valve element over one movable valve element by throttling according to the operation amount for another movable valve element is provided, and the controller and the solenoid proportional valve are
This priority valve is controlled, and since the flow rate of the fluid supplied to one movable valve body is throttled according to the operation amount for the other movable valve body by the priority valve, it can be handled via one movable valve body. With respect to the flow rate supplied to the corresponding actuator, a larger flow rate can be supplied to the corresponding actuator via the other movable valve body.

The invention described in claim 7 is the fluid pressure circuit according to any one of claims 4 to 6, wherein the pump is
It is a variable displacement pump that is equipped with a regulator that controls the displacement of the variable displacement pump by a control signal output from the controller according to the operation amount of the valve device. Since the regulator is operated by the output control signal to control the pump flow rate, a conventional device for controlling the pump flow rate such as a relief valve for negative control is unnecessary.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A valve device according to the present invention is shown in FIG.
And referring to the embodiment shown in FIG. 2, a hydraulic circuit as a fluid pressure circuit according to the present invention will be described with reference to the embodiment shown in FIGS. 3 and 4.

FIGS. 1 and 2 show a hybrid remote control valve 21 as a valve device having a structure in which an electric operating lever (electric joystick) and a hydraulic pilot control valve are combined.

As shown in FIG. 1, the hybrid remote control valve 21 is an operating body 22 which can be moved in any direction by a manual operation, and a pilot operating type hydraulic circuit according to the operation amount of the operating body 22. A hydraulic remote control valve 24 as a pilot control valve that outputs pilot pressure to the main control valve 23, and an electric signal corresponding to the operation amount to the controller 25 for hydraulic circuit control by electrically detecting the operation amount of the operating body 22. And a manipulated variable detecting device 26 for outputting.

The operating body 22 is provided with a universal joint 28 such as a universal joint or a ball joint on the head of a screw 27 screwed to the center of the upper portion of the hydraulic remote control valve 24.
It is rotatably provided in any direction of 0 °.

When the universal joint 28 is a universal joint, the universal joint 28 is pivoted in the left-right direction as one direction around the pivot shaft 31 in the front-rear direction in FIG. It has a joint member 33 centered on 32 and rotated in the front-back direction as the other direction intersecting with one direction.

A disk 35 as a rod pressing member is screwed into the threaded portion 34 of the joint member 33, and a lower portion of the adjusting nut 36 is screwed into the screw portion 34, and the upper portion and the upper portion of the adjusting nut 36 are provided. The lower part of the lever 38 is screwed into the lock nut 37 and is fixed by the lock nut 37. A handle 39 is integrally provided on the upper portion of the lever 38.

As described above, the lever 38 and the operation amount detecting device 26, which are rotatably provided in the arbitrary direction by the universal joint 28, have the groove portion 41 provided at the lower portion of the handle 39 and the hydraulic remote control valve 24. It is covered with a bellows-like cover 43 fitted in a groove 42 provided in the upper part.

Further, the hydraulic remote control valve 24 is pushed down above the valve body 44 by the operating body 22 which is rotated in the left-right direction about the rotation support shaft 31 in the front-back direction in FIG. A pair of left and right push rods 45 are fitted in a liquid-tight manner so that they can slide freely.
Underneath these push rods 45 are intervening rods, respectively.
A pair of left and right spools 47 provided via 46 are slidably fitted to the lower portion of the valve body 44.

Similarly, a pair of front and rear push rods (not shown) pushed down by a manipulating body 22 pivoted in the front-rear direction about a pivot shaft 32 in the left-right direction in FIG. ,
Liquid-tightly slidably fitted on the upper portion of the valve body 44, and a pair of front and rear spools (ie, upper and lower portions in FIG.
A pair of spools 48) is slidably fitted to the lower portion of the valve body 44.

Each push rod 45 is urged upward through a seat 52 by a large diameter spring 51 provided in the valve body 44. The spools 47 and 48 are urged downward by the spring 53 provided on the inner diameter side of the spring 51, but can be moved upward by the return pressure.

The pair of left and right spools 47 outputs pilot pressure to one end surface or the other end surface of one stem 54 as one movable valve body of the main control valve 23,
A pair of spools 48 that do not appear in FIG. 1 output pilot pressure to one end surface or the other end surface of another stem (not shown) as another movable valve element of the main control valve 23. .

In the valve body 44, a primary passage 56 on the pilot primary pressure supply side that communicates with a pilot pump 55, a return passage 59 in a bushing 58 that communicates with a tank 57, and a return chamber that communicates therewith. 61 and the position of the spool 47 can communicate with the primary side passage 56 via the passage 62 or the passage 63
A secondary passage 64 on the pilot secondary pressure supply side is provided which can communicate with the return chamber 61 via the above.

Therefore, when the spool 47 moves downward, the primary side passage 56 and the secondary side passage 64 communicate with each other, and the spool
When 47 moves upward, the secondary passage 64 and the return chamber 61 communicate with each other.

A plate 65 is liquid-tightly attached to the lower surface of the valve body 44, and a port 66 communicating with the two secondary passages 64 and a port communicating with the primary passage 56 are mounted on the plate 65. A port (not shown) communicating with the return passage 59 (not shown) is provided respectively.

The ports 66 of the two secondary passages 64 are connected to one end of the stem 54 of the main control valve 23 for directional control and throttle control of the hydraulic oil supplied from the variable displacement pump 67 as a pump to the actuator 68. Each pilot line 69 communicates with the other end.

The manipulated variable detecting device 26 is installed above the valve body 44 of the hydraulic remote control valve 24. That is, in FIG. 2, the sensor mounting portion 71 is provided at the location shown on the lower side, and the sensor mounting portion 71 has a rotation support shaft in the front-back direction in FIG.
One angle sensor 72 as one operation amount sensor such as a potentiometer that outputs an electric signal according to a rotation angle as an operation amount in one direction by rotating the lever in the left-right direction about 31 is its sensor body. Pair of mounting plates protruding from the section
At 73, they are fixed by a pair of screws 74.

Similarly, a sensor mounting portion 75 is provided at the position shown on the left side of FIG. 2, and the sensor mounting portion 75 has a lever rotation in the front-rear direction centered on the pivot shaft 32 in the left-right direction of FIG. Another angle sensor 76 as another operation amount sensor such as a potentiometer that outputs an electric signal according to the rotation angle as the operation amount in the other direction by a pair of attachments protruding from the sensor main body. The plate 77 is fixed by a pair of screws 78.

Further, bearings 81 and 82 are provided on the upper surface of the valve body 44 via the lever 38 of the operating body 22 at positions opposite to the angle sensors 72 and 76, respectively. Between the angle sensors 72, 76 and the bearings 81, 82 facing them, two slides as operating body angle transmitting members for transmitting the rotation angle of the lever 38 to the angle sensors 72, 76. Rings 83 and 84 are provided to intersect.

These slide rings 83, 84 are operation bodies.
A pair of parallel-shaped portions 86 slidably contacting one side portion and the other side portion of the collar 85 (FIG. 1) fitted to the 22 adjusting nuts 36.
And a shaft support plate portion connecting between both ends of these parallel portions 86.
And 87 form an endless shape.

Shaft supporting plate portions 87 at both ends of these slide rings 83 and 84 are bent downward, and these shaft supporting plate portions 87 are arranged on the extensions of the respective rotation supporting shafts 31 and 32. Shaft fitting portion 89 that fits with the shaft 88 (FIG. 1) of the angle sensors 72 and 76 that have been fixed,
Bearings 81 and 82 arranged on the extensions of the respective rotation support shafts 31 and 32 and a shaft 90 (FIG. 1) that fits are integrally provided. Shaft 88 of each angle sensor 72, 76 and each slide ring 8
After the shaft fitting portions 89 of 3, 84 are fitted, they are integrated by the screw 91.

As shown in FIG. 1, a cover mounting portion 92 is fitted on the valve main body 44, and a sensor cover 93 is mounted on the cover mounting portion 92. 76 covered and protected.

A wiring cover 94 is fitted to the lower portion of the valve body 44, and a bushing 95 fitted to the wiring cover 94 is fitted.
The electric wire 96 for taking out an electric signal, which is connected to the angle sensors 72 and 76, is pulled out to the outside. An electric wire 97 connected to a switch (not shown) provided on the handle 39 is drawn to the outside via the bellows-shaped cover 43 and the wiring cover 94.

Next, the function and effect of the hybrid remote control valve 21 shown in FIGS. 1 and 2 will be described.

In FIG. 1, when the operating body 22 is rotated to the right, for example, the disc 35 is tilted to the right, and the push rod on the right side is rotated.
Push down 45. When the push rod 45 is lowered, the right seat 52 is lowered while compressing the inner and outer springs 51 and 53.

The spool 47 on the right side is pushed down by the compressive force of the inner spring 53 to open the lower passage 62, and the pilot primary pressure oil supplied from the pilot pump 55 into the primary passage 56 is The pressure is controlled in the passage 62 in accordance with the displacement amount of the spool 47 and flows as pilot secondary pressure oil to the right side secondary passage 64, and further from the right port 66 through the pilot line 69 to the stem 54 of the main control valve 23. Acts on the left side of.

The stem 54 strokes according to this secondary pilot pressure, and controls the direction and flow rate of the hydraulic oil supplied from the variable displacement pump 67 to one side of the actuator 68 and returned from the other side of the actuator 68 to the tank 57. The actuator 68 is controlled to operate at a predetermined speed.

That is, the force of the inner spring 53 increases or decreases according to the lever rotation angle, and the primary passage 56 to the passage 62
The secondary pilot pressure supplied to the secondary passage 64 via the high-low changes, the stroke of the stem 54 of the main control valve 23 is controlled, and the amount of hydraulic oil supplied from the variable displacement pump 67 to the actuator 68 is controlled. The actuator
The operating speed of 68 is determined.

On the other hand, the pilot return oil extruded from the right side of the stem 54 is returned to the secondary side passage 64 on the left side from the port 66 via the pilot line 69, and at this time, the left push rod 45 is ejected from the disc 35. Since it is opened, the left spool 47 moves upward against the inner spring 53 due to the pressure difference acting on both ends of the spool 47, and opens the upper passage 63. Therefore, the left side secondary passage 64
The pilot return oil returned to the tank is returned to the return chamber 61 via this passage 63, and further to the tank via the return passage 59.
Returned to 57.

At the same time, the lever operation when the operating body 22 is rotated to the right in FIG. 1 is performed by the slide ring 83 provided in the vertical direction in FIG. 2 and the axis of the angle sensor 72 such as a potentiometer located in the lower side in FIG. Is transmitted to this angle sensor
The lever rotation angle is electrically detected by 72, and the controller 25 can obtain an angle signal from the angle sensor 72.

Such a lever operation is an example of a single spool operation in which the operating body 22 is pivotally operated only in the left-right direction around the pivot shaft 31 in the front-back direction of FIG. When tilted diagonally upward or diagonally downward, the spool 47 arranged in the vertical direction together with the spool 47 arranged in the horizontal direction in FIG.
Is simultaneously moved, and the stem 54 is pilot-operated by the pilot secondary pressure from the spool 47 arranged in the left-right direction, and at the same time, another stem is pilot-operated by the pilot secondary pressure from the spool 48 arranged vertically. Then, it becomes possible to operate the actuator 68 and another actuator in an interlocking manner with one operating body 22.

At this time, the two slide rings 83, 84 provided in the vertical direction and the horizontal direction in FIG. 2 are simultaneously rotated, and the axis of the angle sensor 72 positioned on the lower side in FIG. 2 and the angle sensor 76 positioned on the left side. The two-direction components of the lever operation are transmitted to the axis of the, and these angle sensors 72 and 76 simultaneously detect the lever rotation angles in the two directions. An angle signal corresponding to the secondary pilot pressure output to the stem 54 can be obtained.

Further, the controller 25 includes two angle sensors 72 mounted on the single hybrid remote control valve 21,
In addition to obtaining the angle signal corresponding to the secondary pilot pressure output from the two stems from the 76, it is also output to the multiple stems from the multiple angle sensors 72 and 76 mounted on the multiple hybrid remote control valves 21. It is also possible to obtain an angle signal corresponding to the pilot secondary pressure.

The controller 25 includes a plurality of angle sensors 72,
The angle signal detected at 76 is read and arithmetic processing is performed to determine the interlocking operation state of the plurality of actuators, and the hydraulic circuit is controlled according to the interlocking operation state.

In this manner, the pilot secondary pressure output from the hydraulic remote control valve 24 allows the stem 54 of the main control valve 23, which is not of a solenoid type, to be robust and hard to break down, according to the operation amount of the operation body 22 and directly pilot-operated. In addition, since the operation amount of the operation body 22 is directly detected by the operation amount detection device 26 and an electric signal corresponding to the operation amount is output to the controller 25 for controlling the fluid pressure circuit, a conventional pressure switch or pressure sensor, etc. The controller 25 can accurately grasp the interlocking operation state by the electric signal output from the operation amount detecting device 26 without installing a pressure detecting means for detecting the interlocking operating state in the fluid pressure circuit.

Further, when one operating body 22 is simultaneously rotated around the rotation support shaft 31 in the front-rear direction and the rotation support shaft 32 in the left-right direction in FIG. 1, the left and right spools 47 and the upper and lower spools in FIG.
48 can be easily operated in conjunction with each other, and the operation amount of each spool 47, 48 can be detected by the angle sensor 72 on the lower side and the angle sensor 76 on the left side in FIG.

As described above, 1. Angle sensors 72 and 76 of the operation amount detection device 26 that directly detects the lever operation angle on the lever-operated hydraulic remote control valve 24.
Is attached to form a hybrid remote control valve 21.

2. The pilot operated main control valve 23 is the pilot 2 generated from the hydraulic remote control valve 24.
Drive at next pressure.

3. The interlocking operation state is determined by reading the angle signals detected by the angle sensors 72 and 76 with the controller 25.

4. The controller 25 includes angle sensors 72 and 76.
The angle signal obtained in step 3 is arithmetically processed to output a control signal to the hydraulic circuit, and the hydraulic circuit is controlled according to the interlocking operation state as described below.

5. The angle sensors 72 and 76 may be mounted not only on the lever-operated hydraulic remote control valve 24 but also on the pedal-operated hydraulic remote control valve.

Next, FIG. 3 shows an application example in which hybrid remote control valves 21a and 21b similar to the hybrid remote control valve 21 shown in FIGS. 1 and 2 are applied to a hydraulic circuit of a hydraulic excavator. FIG. 4 shows the corresponding actuator.

As shown in FIG. 3, the discharge lines 101 and 102 connected to the discharge ports of the pair of variable displacement pumps 67a and 67b, which are hydraulic pressure sources, are connected to the pilot-operated main control valve 23. There is.

The main control valve 23 controls the direction and throttle of the hydraulic oil discharged from the variable displacement pumps 67a and 67b to control a plurality of actuators (the left and right traveling motors shown in FIG. 4, (Swing motor, boom cylinder 15, stick cylinder 17, bucket cylinder 19, etc.) Stem 54 as a plurality of movable valve bodies
TrL, 54TrR, 54Sw, 54Bm1, 54Bm2, 54St1, 54St2, 54B
It has k and 54 Au.

That is, from the variable displacement pump 67a on the right side to the discharge line 101, the straight traveling valve 103 and the parallel passage 10.
As a stem to which hydraulic oil is supplied via 4, a right traveling stem 54TrR, a bucket stem 54Bk, an attachment stem 54Au, a second stick stem 54St2 as a specific movable valve body, and a boom as another movable valve body. The first stem 54Bm1 for the vehicle is provided.

A left traveling stem 54TrL and a stick as one movable valve body are provided as a stem for receiving hydraulic oil from the left variable displacement pump 67b through the discharge line 102, the straight traveling valve 103 or the parallel passage 105. A first stem 54St1 for operation, a turning stem 54Sw as another movable valve body, and a second boom stem 54Bm2 are provided.

A priority valve 106, which is a pilot operated flow control valve, is provided together with a check valve 107 between the first stick stem 54St1 and the turning stem 54Sw.

The priority valve 106 restricts the flow rate of the hydraulic oil supplied from the parallel passage 105 to the hydraulic oil supply port of the first stick stem 54St1 in accordance with the turning / stick interlocking operation state, so that the stick first valve 54St1 1 Priority is given to the flow rate of hydraulic oil supplied from the stem 54St1 to the turning stem 54Sw,
The turning motion is prioritized over the stick motion.

A tandem passage 108 passing through the second stick stem 54St2 is also connected to the hydraulic oil supply port of the first stick stem 54St1.

Discharge line of each variable displacement type pump 67a, 67b
101 and 102 communicate with the tank 57 via the center bypass passages 109 and 110 when the stems are in the neutral position.

Further, for example, the hybrid remote control valve 21a shown on the right side of FIG. 3 has a pilot line 69aBm for supplying pilot pressure controlled by one spool 47.
Is connected to the end surfaces of the boom first stem 54Bm1 and the boom second stem 54Bm2, and supplies the pilot pressure controlled by the other spool 48 to the pilot line 69aB.
k is communicated with the end surface of the bucket stem 54Bk.

Similarly, in the hybrid remote control valve 21b shown on the left side of FIG. 3, a pilot line 69bSw for supplying pilot pressure controlled by one spool 47 is connected to the end surface of the turning stem 54Sw, and the other spool. A pilot line 69bSt for supplying pilot pressure controlled by 48 is connected to the end faces of the first stick stem 54St1 and the second stick stem 54St2.

Each pilot line 69aBm, 69aBk, 69bS
Although w and 69bSt are arranged only on one side of each stem in the drawing, it goes without saying that they are also arranged on the opposite side.

Then, the hybrid remote control valve 21 on the right side
a is a boom first stem 54Bm1, a boom second stem 54
The Bm2 and the bucket stem 54Bk are simultaneously operated by the pilot secondary pressure according to the operation amount of one operating body 22, and the hybrid remote control valve 21b on the left side is the first stem 54St1 for stick and the second stem for stick. 54St
2. Simultaneously operate the turning stem 54Sw by the pilot secondary pressure according to the operation amount of one operating body 22.

Each of these hybrid remote control valves 21a, 2
The two angle sensors 72 and 76 (FIG. 2) attached to 1b are respectively connected to the input section of the controller 25 by the electric wire 96 for extracting the electric signal. Then, the respective angle sensors 72 and 76 simultaneously output electric signals in two directions according to the operation direction and the operation amount of the operating body 22.

The controller 25 arithmetically processes the electric signals output from the two angle sensors 72 and 76 (FIG. 2) of the hybrid remote control valves 21a and 21b, determines the interlocking operation state, and determines the interlocking operation state. The corresponding control signal is output to the electro-oil conversion means and the pump control means electrically connected by the control signal output lines 111, 112, 113, 114 and 115.

As the electro-hydraulic converting means, for example, the electromagnetic proportional valve 11 is provided for the pilot pressure acting portion of the second stick stem 54St2, the priority valve 106, and the second boom stem 54Bm2.
6, 117, 118 are connected to these solenoid proportional valves 116, 11
7, 118 outputs the pilot control pressure corresponding to the control signal from the controller 25 to the second stick stem 54St2, the priority valve 106, and the second boom stem 54Bm2 to put these stems in an interlocking operation state. Change accordingly.

As the pump control means, regulators 119 and 120 are provided for the capacity varying means such as the swash plates in the variable displacement pumps 67a and 67b. These regulators 119 and 120 are hybrid remote control valves 21a. ， 2
The displacements of the variable displacement pumps 67a, 67b are variably controlled by a control signal output from the controller 25 according to the manipulated variable of 1b.

Next, the function and effect of the circuit shown in FIG. 3 will be described.

The first boom remote stem 54Bm1 and the second boom boom stem 54B are controlled by the hybrid remote control valve 21a.
In the interlocking operation state in which the pilot operation is performed on m2 and at the same time, the pilot operation is performed on the first stick stem 54St1 and the second stick stem 54St2 by the other hybrid remote control valve 21b.
The controller 25 detected by 76 (FIG. 2) acts on the second stick stem 54St2 as a specific movable valve body through the solenoid proportional valve 116 by the control signal according to the boom side lever operation amount of the hybrid remote control valve 21a. The second pilot stem 54St2 is controlled to return to the neutral position by increasing the pilot pressure.

That is, in the case of a single operation in which only the hybrid remote control valve 21b is lever-operated to the stick side,
1st stem 54St1 for sticks and 2nd for sticks
The stem 54St2 is driven by the pilot secondary pressure from the hybrid remote control valve 21b, and then the two hybrid remote control valves 21a and 21b are simultaneously operated by the levers to connect the boom cylinder 15 and the stick cylinder 17 to each other.
When the stick interlocking operation state is entered, as the specific gravity of the boom operation amount increases, the controller 25
The second stem 54St2 for stick is controlled to be pushed back toward the neutral position through 6

As a result, the second stem 54St for sticks
It is possible to suppress the flow rate of the hydraulic oil supplied to the corresponding stick cylinder 17 via 2 and, by that much, from the variable displacement pump 67a common to the second stem 54St2 for stick, the first stem for boom as another movable valve body It is possible to secure the necessary hydraulic oil flow rate that is supplied to the corresponding boom cylinder 15 via 54Bm1, and to avoid the pressure interference between the second stick stem 54St2 and the first boom boom stem 54Bm1. Can supply pressure.

When the stick cylinder 17 and the swing motor are operated by the hybrid remote control valve 21b, the controller 25 sets the priority valve 106 through the solenoid proportional valve 117 according to the swing side lever operation amount of the hybrid remote control valve 21b. By controlling and pilot-operating the priority valve 106 in the flow throttle direction by the pilot pressure from the solenoid proportional valve 117, it is supplied from the parallel passage 105 through the priority valve 106 to the first stick stem 54St1 as one movable valve body. The flow rate to be reduced is reduced, and the common parallel passage 105
From other turning valve stem 54Sw as a movable valve,
Can supply more flow rate.

That is, in the interlocked operation state of the stick 16 and the upper swing body 13, the priority valve 106 is controlled by the controller 25 and the solenoid proportional valve 117, and the parallel passage 105 is controlled according to the swing side lever operation amount of the hybrid remote control valve 21b.
Is variably controlled so that the ratio of the flow rate supplied from the parallel passage 105 to the turning stem 54Sw to the flow rate supplied to the first stick stem 54St1 via the priority valve 106 from the parallel passage 105 is increased. The flow rate supplied from the second stick stem 54St2 through the tandem passage 108 to the first stick stem 54St1 via the priority valve 106 to the first stick stem 54St1 is increased. It is variably controlled.

Further, in response to the angle signal from the angle sensors 72 and 76 (FIG. 2) corresponding to the lever operation amount of the hybrid remote control valves 21a and 21b, the controller 25 controls the control line 11
Since a control signal is output to the regulators 119 and 120 via 4 and 115 to operate the regulators 119 and 120 to control the pump flow rate discharged from the variable displacement pumps 67a and 67b, the conventional relief valve for negative control is used. Therefore, a hydraulic device for controlling the flow rate of the pump such as a so-called negative control relief valve becomes unnecessary.

In this way, the hybrid remote control valve 21
The stems of the main control valve 23 are directly pilot-operated according to the operation amount of the operating body 22, that is, the lever rotation angle by the pilot secondary pressure output from a and 21b, which results from the calculation time in the controller 25. The delay can be prevented, and the controller 25 determines the interlocking operation state by the electric signal output from the angle sensors 72, 76 (FIG. 2) of the hybrid remote control valves 21a, 21b according to the operation amount of the operation body 22. , Outputs a control signal according to the interlocking operation state to the solenoid proportional valves 116, 117, 118,
Since the pilot control pressures corresponding to the control signals from 6, 117, 118 are output to the respective stems 54St2, 54Bm2 and the priority valve 106 and these movable valve bodies are changed in accordance with the interlocking operation state, the electronic devices such as the controller 25 If an abnormality occurs in the control system, the interlocking operability may be impaired, but each stem of each main control valve 23 is pilot operated from the pilot secondary pressure according to the lever operation amount of the hybrid remote control valves 21a and 21b. The basic function of doing is not impaired.

As described above, the hybrid remote control valve 21
Is a lever-operated or pedal-operated hydraulic remote control valve
Since the angle sensors 72 and 76 (Fig. 2) are attached to the 24, they have the following features.

The main control valve 23 is not a solenoid type, but a proven and robust one can be used, which is driven and controlled by the pilot secondary pressure of the hydraulic remote control valve 24.

Since the interlocking operation state is detected by the angle sensors 72 and 76 which interlock with the operating body 22, it is not necessary to mount a pressure switch or a pressure sensor in the hydraulic circuit, and a hydraulic logic circuit is provided in the main control valve 23. There is no need to incorporate it.

In other words, the interlocking operation state of the hydraulic excavator or the like can be accurately grasped without mounting a pressure switch, a pressure sensor or the like.

That is, the angle sensors 72,
Since the interlocking operation state of the hybrid remote control valve 21 can be known from 76, the interlocking operation state can be accurately grasped without being affected by the pilot primary pressure or the hydraulic oil temperature.

Since the main control valve 23 is directly driven by the pilot secondary pressure from the hydraulic remote control valve 24, a signal obtained by processing the lever operation signal by the operation controller like an electric operation lever is converted into an electric oil. Then, as compared with the case where each stem of the main control valve 23 is indirectly driven, the delay due to the calculation time in the arithmetic controller does not occur.

Since the angle signals of the angle sensors 72 and 76 interlocked with the operation lever or the operation pedal are used, the earliest signal in time can be obtained after the operation by the operator.

Since the angle signal of the operating lever or the operating pedal is mainly used for changing the hydraulic circuit according to the conditions, even if an abnormality occurs in the electronic control system in the worst case, each of the main control valve 23 can be operated. The basic function of piloting the stem is not compromised.

In the embodiment shown in FIGS. 3 and 4, the hybrid remote control valves 21a and 21b used in the hydraulic excavator and the hybrid remote control valves 21a and 21b are used.
However, the present invention can also be applied to a hybrid remote control valve used in another work machine and a fluid pressure circuit using this hybrid remote control valve.

[0089]

According to the first aspect of the invention, the pilot pressure output from the pilot control valve causes
The main control valve can be directly pilot operated according to the operation amount of the operating body, and the operation amount of the operating body can be directly detected by the operation amount detecting device, and an electric signal corresponding to the operation amount is sent to the controller for controlling the fluid pressure circuit. Because it outputs
The controller accurately determines the interlocked operation state by the electric signal output from the operation amount detection device without installing the pressure detection means for detecting the interlocked operation state of the conventional pressure switch or pressure sensor in the fluid pressure circuit. Can understand.

According to the second aspect of the present invention, one spool and the other spool can be interlocked by one operating body, and the operation amount of each spool is controlled by the one operation amount sensor and the other operation amount. It is possible to accurately grasp the interlocking operation state by detecting each with a sensor.

According to the third aspect of the invention, one operating body can be rotated in an intermediate direction between one direction and the other direction to easily operate the one spool and the other spool in an interlocked manner. The operation amount of each spool can be easily detected by the one angle sensor and the other angle sensor to accurately grasp the interlocking operation state.

According to the fourth aspect of the present invention, the movable valve body of the main control valve is directly pilot-operated according to the operation amount of the operating body by the pilot pressure output from the valve device. It is possible to prevent the delay due to it, and the controller judges the interlocking operation state by the electric signal output from the valve device according to the operation amount of the operating body, and the control signal according to the interlocking operation state is sent to the solenoid proportional valve. When a malfunction occurs in the electronic control system such as the controller, the electromagnetic proportional valve outputs the pilot control pressure according to the control signal to the movable valve body and changes the movable valve body according to the interlocking operation state. Although the interlocking operability may be impaired, the basic function of pilot-operating the movable valve element of the main control valve by the valve device is not impaired.

According to the fifth aspect of the present invention, the pilot pressure acting on the specific movable valve element is controlled to move the specific movable valve element toward the neutral position in accordance with the operation amount for another movable valve element. By controlling the return, the flow rate of the fluid supplied to the corresponding actuator via the specific movable valve element is suppressed, so that the flow rate of the fluid supplied from the common pump to the corresponding actuator via the other movable valve element is controlled. Can be secured.

According to the sixth aspect of the invention, since the flow rate of the fluid supplied to one movable valve body is reduced by the priority valve in accordance with the operation amount for the other movable valve body, one movable valve body is required. It is possible to supply a larger flow rate to the corresponding actuator via the other movable valve body with respect to the flow rate supplied to the corresponding actuator via the above.

According to the seventh aspect of the present invention, the regulator is operated by the control signal output from the controller according to the operation amount of the valve device to control the pump flow rate. Therefore, a pump such as a relief valve for negative control is used. Eliminates the need for conventional equipment to control the flow rate.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a valve device according to the present invention.

FIG. 2 is a horizontal sectional view of the same valve device.

FIG. 3 is a circuit diagram showing an embodiment of a fluid pressure circuit according to the present invention.

FIG. 4 is a front view of a hydraulic excavator to which the above fluid pressure circuit is applied.

[Explanation of symbols]

15, 17, 19 Actuators (boom cylinders, stick cylinders, bucket cylinders) 21 Hybrid remote control valve as a valve device 22 Operating body 23 Main control valve 24 Hydraulic remote control valve as a pilot control valve 25 Controller 26 Operation amount detection device 47 Spool 48 Other spool 54 Stem 54St2 as a movable valve body Stick second as a specific movable valve body Second stem 54Bm1 Boom 1st stem 54St1 as another movable valve body 1st stick as a movable valve body 1st Stem 54Sw Rotating stem as another movable valve body 67 Variable displacement pump as pump 72 One angle sensor as one operation amount sensor 76 Other angle sensor as another operation amount sensor 106 Priority valves 116, 117 , 118 Solenoid proportional valve 119,120 Regulator

Continued front page    (72) Inventor Seiichi Akiyama             4-10-1, Yoga, Setagaya-ku, Tokyo             Within Mitsubishi Corporation F-term (reference) 2D003 AA01 AB02 AB03 AB05 BA08                       CA04 DA03 DA04 DB02 DB04                       EA00 EA02                 3H002 BA01 BB09 BC01 BD04 BE02                 3H089 AA60 BB15 BB17 BB27 CC01                       CC11 DA03 DA07 DB32 EE06                       EE22 EE36 FF05 GG02 JJ02

Claims (7)

[Claims] 1. An operating body, a pilot control valve for outputting pilot pressure to a pilot-operated main control valve of a fluid pressure circuit according to the operating volume of the operating body, and an operating volume of the operating body electrically detected. And a manipulated variable detecting device for outputting an electric signal according to a manipulated variable to a controller for controlling a fluid pressure circuit. 2. The operating body is provided so as to be movable in any direction, and the pilot control valve is pushed and moved by the operating body operated in one direction to output pilot pressure to one movable valve body of the main control valve. And a spool that outputs a pilot pressure to another movable valve body of the main control valve that is pressed and moved by an operating body that is operated in the other direction that intersects with one direction. The one-operation amount sensor that outputs a signal according to the operation amount in one direction, and the other operation amount sensor that outputs a signal according to the operation amount in the other direction. Valve device. 3. The operating body is rotatably provided in an arbitrary direction, and one operation amount sensor is one angle sensor that outputs a signal according to a rotating angle in one direction, and another operation amount sensor. 3. The valve device according to claim 2, wherein the quantity sensor is another angle sensor that outputs a signal corresponding to a rotation angle in another direction. 4. A plurality of movable valve bodies of a main control valve for controlling the direction of fluid discharged from a pump and supplying the plurality of actuators to the plurality of actuators, and a plurality of movable valve bodies by pilot pressure according to an operation amount of an operating body. A valve device that performs pilot operation and outputs an electrical signal according to the operation amount of the operating body, and a controller that determines the interlocking operation state from the electrical signal output from the valve device and outputs a control signal according to the interlocking operation state. A fluid pressure circuit, comprising: a pilot control pressure according to a control signal from a controller, which is output to the movable valve body to change the movable valve body according to an interlocking operation state. 5. The controller and the solenoid proportional valve control a pilot pressure acting on a specific movable valve element of a specific movable valve element and another movable valve element supplied with a fluid from a common pump to control a specific movable valve element. The fluid pressure circuit according to claim 4, wherein the movable valve body is controlled to return to the neutral position in accordance with the operation amount for another movable valve body. 6. A single movable valve body, wherein the flow rate of a fluid supplied to one movable valve body is reduced with respect to the flow rate of a fluid supplied to another movable valve body according to an operation amount for another movable valve body. The fluid pressure circuit according to claim 4, further comprising a priority valve that prioritizes a flow rate supplied to another movable valve element rather than the valve element, and the controller and the solenoid proportional valve control the priority valve. 7. The pump is a variable displacement pump, comprising a regulator for controlling the displacement of the variable displacement pump according to a control signal output from the controller according to the manipulated variable of the valve device. Item 7. The fluid pressure circuit according to any one of Items 4 to 6.