JPS5935660Y2 - Structure of pilot valve for operating model of work equipment - Google Patents

Description

[Detailed description of the invention] The present invention has an arm attached to a boom that can be driven and swung vertically, and a work tool attached to the arm, each of which is driven around an axis that is parallel or almost parallel to the swing axis of the boom. A pilot valve for controlling control valves of the boom and arm is provided with a model that is rotatably attached and operates proportionally to reduction in response to changes in the position and attitude of the boom and arm,
The boom and arm are configured to be operated by the model into the engaged state when the position and orientation of the model are different from those of the boom and arm, and to be operated into the off state by driving the boom or arm, and the boom and arm are operated by the model into the off state. The present invention relates to a work machine configured to operate a machine.

When operating the model on this type of machine, the initial
In this case, the model is operated after the sliding operation force on the spool exceeds the maximum static friction force due to static friction between the sliding spool and the valve body, but once the spool starts sliding, the valve body The resistance between the box and the box is converted into kinetic friction, and the resistance decreases rapidly, and conventionally, with the conversion from the above-mentioned maximum static friction to kinetic friction, which accounts for the total resistance applied to model operation, Even if the ratio of the amount of resistance change to be changed is a dog, and even if an attempt is made to perform a minute operation, the dynamic inertia caused by the above-mentioned resistance change acts greatly, and the amount of operation tends to become large, resulting in problems such as hunting.

In view of the above points, it is an object of the present invention to make it possible to easily perform minute operations on a model, suppress hunting, and perform desired excavation work well.

Next, embodiments of the present invention will be explained in detail based on illustrative drawings.

Describe.

A swivel base 2 is provided on a traveling vehicle body equipped with a crawler traveling device 1 so that it can freely travel around two vertical axes, a control cabin 3 is provided on the swivel base 2, and an excavation device 4 is provided at the front of the vehicle. 1. The swivel table 2 and the excavation device 4 are configured to be driven by hydraulic pressure, which is an example of a fluid pressure type, and therefore,
The work machine is configured to perform ground excavation work.

The excavation equipment 4 has a boom 5 pivotally connected to a rotating table 2, an arm 6 to the boom 5, and a packet 7, which is an example of a working tool, pivotally supported to the boom 5. Connect the swivel base 2 and boom 5, boom 5 and arm 6
, and a cylinder 8. between the arm 6 and the bucket 7, respectively. 9
．． 10 is interposed therebetween, and the boom 5, arm 6, and packet 7 are driven and moved by the operation of cylinders 8.

In the control cabin 3, there is provided a model B that operates proportionally to the change in position and attitude of the boom 5 and the arm 6, and the cylinders 8, 8 of the boom 5 and the arm 6, respectively, operate in conjunction with the operation of the model B. The control valves V and (2) for Model 9 are automatically operated via a pilot pressure mechanism 11, and the boom 5 and arm 6 can be driven by operations for Model B.

That is, to configure model B, a first link 5a corresponding to the boom 5 is rotatably connected to the base portion 12, and a second link 6a corresponding to the arm 6 is connected to the first link 5a. are rotatably pivotally connected, and the second link 6
The operating tool 13 is rotatably provided at the a.

In order to link the first link 5a and the boom 5, an arm member 14 integrally extended from the first link 5a and an angle member 15 provided swingably around the coaxial center X with the boom 5 are connected to one end by a rond 16. The sliding spool 18 of the pilot valve 1 is connected to the other end of the angle member 15 through the boom 5 and is attached to a plate 17 extending from the boom 5 into the cabin 3 so as to swing integrally therewith. The valve V1 is operated in conjunction with the operation of the model B, and pilot pressure is applied to one of the pressurizing chambers R and R formed in the two Rondo type cylinders 19 that are linked to the boom control valve (2). , so that the boom 5 is driven up or down, and as the boom 5 is driven and displaced, the plate 17, that is, the valve body 20 of the valve 1, moves against the sliding spool 18.
The structure is such that the boom 5 is displaced in the valve closing direction and automatically stopped, and the boom 5 is driven and displaced by an amount corresponding to the amount of operation of the first link 5a in model B.

In order to link the second link 6a and the arm 6, the dogleg-shaped member 21 and the pilot valve 1 are individually swingable around the pivot axis 0 to the base portion 12 of the first link 5a. The attached plate 22 is pivotally connected, and the second link 6
While interlocking and connecting one end side of the doglegged member 21,
The other end of the doglegged member 21 and the sliding spool 18 of the valve 1 are interlocked and connected, and the arm 6 and the plate 2
2 are interlocked and connected via a pair of release wires 23° 23 so that the plate 22 integrally swings around the axis 0 as the arm 6 swings relative to the boom 5. Similarly, the configuration is such that the arm 6 is driven and displaced by an amount corresponding to the amount of operation of the second link 6a with respect to the first link 5a in model B.

In addition, in order to link the packet 7 with the operating tool 13 (mini-bucket) 7a, a plate 2 is attached to the pilot valve V1 so as to be swingable around the rotation axis Y of the operating tool 13.
The arm member 25 integrally extended from the operating tool 13 and the sliding spool 18 of the valve 1 are interlocked and connected, and the plate 24 and the packet 7 are connected via release wires 26 and 26. The packets 7 are connected in conjunction with each other, and are configured to drive and displace the packet 7 by an amount corresponding to the amount of rotation operation of the operating tool 13.

Each of the pilot valves (1) is constructed by attaching a spool 18 with an operated portion 18a protruding to the outside of the valve box 20 so as to be freely slidable, as shown in FIG. At the same time, a spring 27 is interposed between the valve box 20 and the spool 18, and the spring 27 is initially deformed by being engaged with the stopper 31 via the member 32.
The structure is such that when the spool 18 starts sliding, a resistance greater than the maximum static friction force can be applied.

A cylindrical valve body 28 is interposed between the spool 18 and the valve body 20 so as to be slidable relative to each other, and return springs 29 and 29 are provided between both ends of the cylindrical valve body 28 and the valve body 20, respectively. When the spool 18 is slid and displaced as the model B is operated, the output port A communicates with the pump port A1 and the pressurizing chambers R, R of the two Rondo type cylinders 19.
2. When one of A3 is communicated with the output capo)
A2. A pressurized chamber r is connected to the other of A3 and the tank port 1'A4, and is formed between the pump port 1'A1, both ends of the cylindrical valve body 28, and the valve box 20.

Flow paths rl and r formed with different phases in the valve box 20
.

Pressurized fluid is also supplied to one pressurizing chamber r, and the fluid pressure causes the cylindrical valve body 28 to slide against the biasing force of the return spring 29 and displace it to the closed position. The configuration is such that pressurized fluid in an amount corresponding to the amount of sliding displacement of the spool 18 is sequentially supplied to the pressurizing chambers R of both Rondo type cylinders 19.

In addition, the boom 5, arm 6, or bucket 7 is driven and displaced in response to the pilot pressure supply, and the valve body 20 is accordingly slid against the spool 18 and the cylindrical valve body 28, automatically returning to the initial state. be done.

The ends E of each of the return springs 29 and 29 that contact the cylindrical valve body 28 are cut so as to make surface contact over the entire circumference or almost the entire circumference, and when the valve body 28 is in the neutral position, The ends E, E are configured to directly abut stopper portions 30, 30 formed on the valve body 20, respectively.

In summary, this invention is a working machine that has been officially registered.
The pilot valve (1) includes a spool 1 in which the operated portion 18a of the valve body 20 protrudes outside the valve body 20.
8 and a cylindrical valve body 28 fitted externally on this spool 18 are respectively internally slidably relative to each other, and the cylindrical valve body 28
A return spring 29.2 is installed between both ends of the valve body 20 and the valve body 20, respectively.
9 and a Calo pressure chamber r that slides the cylindrical valve body 28 by pressurization.
, r are provided, and the pressurized chambers r, r and the output port A are provided.
2. Pump port A1 and one output port A2 communicate with each other by sliding displacement of the spool 18 by the operation of model B, and the other output port A
3 and the tank port A4 are configured to communicate with each other, and the pilot pressure in the pressurizing chamber connected to the one output port A2 is maintained in response to the opening operation of the valve due to the sliding displacement of the spool 18 from the neutral position. Spool 18 due to increase
The cylindrical valve body 28 is configured to follow the sliding displacement direction to close the valve, and a spring 27 is provided between the valve box and the spool 18 to return the spool 18 to the neutral position. The spring 27 is compressed and deformed in advance by being engaged with the stopper 31 so as to be deformed with an operating force greater than its static maximum frictional resistance force for sliding the spool from the neutral position.

(Function) By operating the model B, the operated portion 18a of the spool 18
Apply operating force to spool 1 of valve ■1 to pylon 1.
8 is slid from the neutral position, a force 9 is passed between the pump port A1 and one of the output ports A2, and the control valve V of the work tool 7 or the arm 6 is actuated by pilot pressure.

Then, in order to drive the work tool 7 or the arm 6,
- When the operation control of the roll valve ■ is completed and the pilot pressure on the one output port A2 side increases, the pressure in the one output pressure chamber r increases accordingly, and the cylindrical valve body 28 Pump port A by following the sliding direction
1 and the one output capo 1'A2 is cut off.

The operation of the control valve ■ causes the work tool 7 or the arm 6 to follow the movement of the model B and operate proportionally to the reduction, and the drive of the work tool 7 or the arm 6 causes the control I/roll valve V1 to be turned off. Spool 1
8 moves relative to the valve box 20 and returns to its original neutral position.

At this time, the cylindrical valve body 28 is pressurized by the pilot pressure of the one pressurizing chamber r and remains in the above-mentioned moving state, and is moved to the neutral position by the spring 29 provided on the opposite side from the one pressurizing chamber. is energized by

Then, along with the return of the spool 18 to the original neutral position, one output port A2 and one tank port A4
The two are connected.

Through the communication between the pump port A1 and the other output port A3, the control valve ■ is controlled to immediately stop the E work tool 7 or the arm 6, and through the communication between the one output port A2 and the tank port 4A4, the control valve The pilot pressure in the one pressurizing chamber r connected to the output port A2 disappears, and the cylindrical valve body 28 is activated by the force of the biased spring 29 on the side opposite to the one pressurizing chamber r. It returns to the Chinese position and the flow path is cut off from the pump port 1'At.

(Effect) In this invention, in particular, when an operating force is applied to the spool 18 of the pilot valve 1 by operating the model B to make it slide against the spring 27 from the valve center position, the spool 18 moves in the operating direction. It slides on the
Since the spring 27 is compressed and deformed in advance so that it is initially deformed with an operating force greater than the static maximum frictional resistance force of the spool 18 in the neutral position, when the static friction at the initial stage of sliding of the spool 18 changes to dynamic friction. This has the advantage that the spool 18 can be slid gradually and smoothly without being forced to slide suddenly due to excessive force, and that minute operations can be easily performed. It has now become possible to perform the desired work, such as positioning reliably.

[Brief explanation of drawings]

The drawings show an embodiment of the structure of a pilot valve for operating a model of a working machine according to the present invention, and FIG. 1 is an overall side view of the working machine, and FIG. 2 is a mechanism diagram showing the state of cooperation between the model and the working device. FIG. 3 is a circuit diagram showing the pilot pressure mechanism, FIG. 4 is a vertical sectional view of the valve, and FIG. 5 is a bottom view of the valve. 5...Boom, 6...Arm, 7...
...Work tool, 18...Spool, 18a.
...Operated part, 20...Valve box, 27, 2
9.29... Spring, 28... Cylindrical valve body, 31... Stopper r, r...
... Pressurized chamber, A1 ... Pump port, A2
．． A3: Output port, A4: Tank port, B: Model, ■: Control valve, ■1: Pilot valve.

Claims (1)

[Scope of utility model registration request] An arm 6 is attached to a boom 5 that can be driven and swung vertically, and a work tool 7 is attached to the arm 6 so that it can be driven and rotated about an axis that is parallel or almost parallel to the swing wheel center of the boom 5, respectively, A model B is provided which operates proportionally to the change in the position and posture of the work tool 7 and arm 6, and pilot valves V1 for controlling the control valves for the work tool 7 and arm 6 are provided. . . . is to be operated by the model B into the entering state when the position and posture of the model B are different from those of the working tool 7 and the arm 6, and to be brought into the cutting state by driving the working tool 7 or the arm 6. The working tool 7 is configured to be operated by the model B.
and a working machine configured to operate the arm 6, in which the pilot valve V1 includes a spool 18 having an operated portion 18a protruding from the valve box 20 to the outside of the valve box 20.
and a cylindrical valve body 28 fitted on the outside of this spool 18 are respectively housed so as to be able to slide relative to each other, and return springs 29 and 29 are provided between both ends of the cylindrical valve body 28 and the valve box 20, respectively.
and pressurized chambers r, r in which the cylindrical valve body 28 is slid by pressurization.
are provided, and the pressurizing chambers r, r and the output port A2. A3°
and the spool 18 by the above-mentioned model B operation.
The sliding displacement of the spool 18 from the neutral position causes the pump port A1 to communicate with one output port A2, and the other output port A3 and the tank port A4 to communicate with each other. In response to the opening operation of the valve, the cylindrical valve body 28 follows the sliding displacement direction of the spool 18 by increasing the pilot pressure in the pressurizing chamber r connected to the one output capo A2, and closes the valve. Furthermore, a spring 27 for returning the spool 18 to the neutral position is provided between the valve box and the spool 18, and the spring 27 has a static maximum frictional resistance force sufficient to slide the spool from the neutral position. The structure of a pilot valve for operating a model of a work machine is characterized in that the pilot valve is compressed and deformed in advance by being locked to a stopper 31 so as to be deformed by a large operating force.