JPS5838051Y2 - Work equipment pilot valve operation structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a work machine such as a backhoe, and more specifically, the present invention includes a boom that can freely swing up and down, an arm that can swing freely around an axis parallel to the swing axis of the boom, and In addition to attaching a work tool that can swing freely around the swing axis on the tip side of the arm,
The present invention relates to a working machine configured to remotely control the boom, arm, and working implement by operating a single module configured to be proportional to the working equipment equipped with the boom, arm, and working implement.

According to the above-mentioned work machine, the movement of the model itself can be magnified proportionally and the boom, arm, and work tool can be remotely controlled. It is possible to carry out excavation work by activating the work tools as desired while performing a combined operation by all the workers at once, and even an unskilled worker can perform the work with high efficiency.

The control valves for the hydraulic drive systems for the boom, arm, and work tools are controlled and operated by pilot valves, and the control valves are controlled on and off by pilot valves, and the movements of the hydraulic drive systems due to the control are controlled by wires and linkages. However, after the pilot valve is operated, it takes time to feed back the movement of the hydraulic drive device to the pilot valve, and this reduces the supply time of pressure fluid to the hydraulic drive device. This, combined with the fact that the supply of pressure fluid shows a rapid rise due to on/off control, causes an overrun in the operation of the hydraulic drive system, resulting in, for example, an increase in the amount of swing of the boom and of the work implement. The amount of rotation is extremely small in terms of time, and most of the rotation is done in a straight line by the swinging motion of the arm. Excavation resulted in a wavy tip trajectory, or the overrun of the boom and work implement was fed back as a reverse operating force on the motile, causing these reversal operations to occur repeatedly, making it difficult to expect smooth straight excavation. .

However, if the control valve is throttled and controlled by adjusting the operating amount of the pilot valve, the control problem will disappear, but it is difficult to intuitively throttle and control the valve in a predetermined manner, and this is accompanied by operational disadvantages. Problems such as increased fluid temperature arise due to throttle control.

The purpose of this invention is to solve the above-mentioned problems, and the technical problem is to be able to perform continuous control as much as possible while using a pilot valve that is controlled in an on-off manner, and The purpose is to automatically gradually reduce the amount of oil sent from the valve so that the valve itself can exert a substantial throttling action.

The technical means of this invention taken to solve the above problems are as follows:
An arm is attached to a boom that can freely swing vertically around an axis parallel to the swing axis, and a work tool that can swing freely around the swing axis on the tip side of the arm is attached. , a working machine configured to remotely control the boom, arm, and working implement by operating one model configured in a scale-down proportion to the working equipment equipped with the boom, the arm, and the working implement; , a first link whose base end is pivotably supported around a first pivot axis with respect to the mounting base side, and a third link parallel to the first pivot axis on the distal end side of the first link. It consists of a second link that is swingably supported via two pivot shafts, and a grip operation member that is rotatable around a third pivot shaft attached to the tip of the second link. the first pivot shaft is fixed to the first link, the second pivot shaft is fixed to the second link, and the third pivot shaft is fixed to the operating member so as to rotate integrally with each other; A contact piece is fixed to the pivot shaft, and a pilot valve for a control valve that controls the expansion and contraction operation of each hydraulic drive device of the working device is positioned on both sides of the contact piece, and the shaft of each pivot shaft is fixed. Each contact piece of each pivot shaft, which is mounted on a mounting frame that is relatively rotatable around a core and rotates integrally with the rotation of each link and operating member, comes into contact with the pilot valve. The pilot valve is configured to actuate the control valve so that the pilot valve operates the boom, arm, or implement of the working device corresponding to the rotatably operated link or operating member in the same direction. and the control valve, and the mounting frame provided around each pivot shaft on the model side and each axis on the working equipment side are connected to each other on the model side at a position corresponding to each axis on the working equipment side. Each mounting frame is interlocked and connected via a connecting tool so as to rotate in the same direction as the mounting frame, and the pilot valve is connected to the control valve from the pump port as the contact piece is suppressed. A spool that opens the refueling port to the side, and a spool located between the pilot valve case and the spool, operates a certain amount as the refueling port is opened, and then closes the pump port and closes the refueling port and the tank. The actuator is switched to communicate with the port side, and the spool and the actuator are returned to their original positions within the valve case as the valve case moves away from the contact piece as the mounting frame rotates. This is because a return spring is provided to return the vehicle to the original state, and the effects obtained by taking this technical means are as follows.

(Function) When the grip operation member of the model is operated and the first link or the second link is swung or the grip operation member is rotated, the grip operation member is integrally fixed to the first link, the second link or the grip operation member. The provided contact piece slides the spool of the pilot valve, and the pump port of the pilot valve and the oil supply port to the control valve are brought into open communication, and pilot pressure is applied to the control valve.

Then, the control valve is switched by this pilot pressure, and the hydraulic drive device that drives the boom, arm, or work implement of the working equipment is activated, causing the boom, arm, or work implement to swing, and the swinging causes the boom, arm, or work implement to swing. The feedback is fed back to the first link, the second link, and the grip operation member corresponding to the work tool, so that the model swings in the same direction as the swing direction of the work device, and the work device is moved in the direction in which the grip operation member operates the model. sways.

Then, when the grip operation member is operated and pilot pressure is applied to the aforementioned control valve, as the pilot pressure increases, the actuator slides against the return spring of the actuator, and the actuator When it slides a certain amount, the pump port is closed, the oil supply port and the tank port are communicated, and the pilot pressure oil to the control valve flows out into the tank, and the control valve becomes open and the hydraulic drive device stops.

Then, the pilot valve moves via its mounting frame in a direction in which the spool moves away from the contact piece by feedback from the working device in response to the application of pilot pressure to the control valve.

At this time, if the spool is subsequently pressed by the grip operating tool, the above-described operation is continuously repeated and the working device swings.

(Effects) Although the control valves of the hydraulic drive devices for booms, arms, and work tools are controlled on and off, the control can be performed as continuously as possible, and the pilot valve itself is automatic. Since it has a squeezing effect, it is possible to smoothly control working devices such as booms and arms, suppress overruns of these working devices, and ensure that the working devices follow the model in a proportionate manner. This has the advantage that the boom, arm and implement can be operated as desired.

That is, when the spool operated by the contact piece begins to open the refueling port, the actuator immediately starts sliding in the direction of closing the refueling port, and the spool begins to open the refueling port, causing the control valve to close. When is switched,
The hydraulic drive device on the working equipment side, which operates in conjunction with this, moves the entire valve case housing the actuator in the same direction as the direction in which the actuator is going to move, and on the opening side of the spool, via the connecting device. During operation, the actuator's operating speed is shifted at a speed proportional to the operating speed of the actuator, so that the hydraulic drive can be operated continuously while the spool continues to be operated, and therefore, the oil supply flow by this spool is Compared to a system in which a hydraulic drive device is controlled by frequently repeating opening and closing of a road, the control is easier to perform smoothly.

Moreover, as mentioned above, while the spool is being operated to the open side, the valve case continues to operate in the same direction at a speed proportional to the operating speed of the actuator, and even after the spool operation is stopped, the valve case continues to operate in the same direction. Although it lags behind the operating speed, the valve case follows suit, so when the actuator attempts to close the oil supply port, the relative speed to the valve case becomes extremely slow, and as a result, the pilot valve This allows the control valve to be switched gently, making it easy to accurately operate the hydraulic drive device on the working device side by the desired amount of operation, and effectively suppressing overruns due to the inertia of the working device.

Embodiments of the present invention will be described below with reference to the drawings.

A swivel base 3 is attached to a machine base 2 equipped with a crawler traveling device 1, an arm A for excavation work as a working device is attached to this swivel base 3, and a driving cabin 4 and an engine 5 are mounted to constitute a backhoe work vehicle. has been done.

The working arm A has an arm 7 at the tip of a boom 6 that is swingable around the horizontal axis P, and a packet 8 as a working tool 8 at the tip of the arm 7, respectively, and the working arm A has an arm 7 at the tip of a boom 6 that is swingable around the horizontal axis P, and a packet 8 as a working tool 8 at the tip of the arm 7, respectively. A fluid pressure cylinder 9 is provided as a hydraulic device that is connected to be swingable around P2 and drives and swings the boom 6, arm 7, and work tool 8, so that the work tool 8 It is configured to draw an excavation work trajectory B.

A model D depicting a trajectory C that decreases proportionally to the working trajectory B of the working arm A is a model D that depicts a trajectory C that is proportionally reduced with respect to the working trajectory B of the working arm A.
The cabin 4 is composed of an operating tool 12 corresponding to
cylinder 9 of the working arm A;
Control valve V for...
・Pilot valve ■1... is linked to model D, and pilot valve ■1 is controlled by model D.
The working arm A is configured to be remotely controlled by the operations of .

As shown in FIG. 4, the pilot valve (1) is a refueling port which is a connection port between the fluid pressure operating part (8) of the control valve (1) and the flexible pipe passages (a, l) for the control pump 13. C, a valve case 14 including a pump port d and a tank port i communicating with the tank T;
In the free state of the spring 15, the actuator 16 having chambers e and f connected to the ports c and d is slidably fitted therein, and in the biased state by the spring 17, the chambers f and e are connected.
A spool 18 having a notch that communicates with the case 14 and the actuator 16 is coaxially slidably fitted therein, and by sliding the spool 18 against the spring 17, the The chamber g is formed so that the chambers e and f communicate with each other, and the spool 1 is placed against the spring 17.
The spool 18 is provided with a flow path that communicates the tank T and the chamber e, which can be closed by a slight movement of the spool 18, and the spool operating portion 18 protrudes from the case 14.The case inner wall 14 on the a side
A chamber j is formed between a and the end surface of the actuator 16, and a flow path k extending between the chamber j and the port C is provided in the case 14.

These two pilot valves V, , V are considered as a pair,
The first pivot shaft 19a is attached to the first link 10 of model D, the second pivot shaft 19b is attached to the second link 11, and the grip operation member 1
A third pivot shaft 19C is fixed to each of the third pivot shafts 19C so as to rotate integrally with each other, and a member 20 that rotates relative to each of the pivot shafts 19a, 19b, 19C, The spool operation parts 18a and 18a are arranged to face each other, and this valve 1. (1) The contact piece 21 for selectively operating 1 is attached to the pivot shafts 19 a , 19 b ,
19C, and in order to transmit the movements of the boom 6, arm 7, and work tool 8 to the mounting frame 20, a push-pull wire 22 is provided as a linking device.

According to the above structure, in the state shown in FIG. 4A, when the spool 18 is operated by the contact piece 21 against the spring 17 to the state shown in the opening in the figure, the flow path is closed and the chamber g The flow paths a and l) communicate with each other, and the pump 13
The control valve (2) is controlled using the pressure fluid from the cylinder as a pilot pressure, and the cylinder 9 is operated.

Then, the fluid pressure for the pilot is determined by operating the control valve V and simultaneously pressurizing the chamber j.
As shown in Figure C, the actuator 16 resists the spring 15.
to the spool operation side, connect port (c) to flow path (a) to flow path, and switch port (d) and chamber f (for flow path (a) to the off state, that is, for the pilot to control control valve ■). Only when fluid pressure is supplied, pilot valve 1 is switched to the off state using the fluid pressure, and flow path a is communicated with tank T to return valve V to the neutral position, during which the operating amount of cylinder 9 is 22 to the mounting frame 20, and as shown in FIG.
Operator 1 until the human power to control the mounting frame 20 is exhausted.
6 slides back and forth to control the control valve (1) intermittently on and off within a short period of time, and to operate the working arm A smoothly without overrun.

[Brief explanation of the drawing]

The drawings show an embodiment of the pilot valve operation structure for a work machine according to the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a remote control system diagram, Fig. 3 is a perspective view of main parts, and Fig. 4 Figure 2 is an explanatory diagram of the operation of the pilot valve. 6...Boom, 7...Arm, 8...
...Work tool, 9...Hydraulic drive device, 10.
...First link, 11...Second link,
12... Grip operation member, 14... Valve case, 15° 17... Spring, 16.
... Actuator, 18 ... Spool, 19
a...First pivot shaft, 19 b...Second pivot shaft, 19C...Third pivot shaft, 20...
...Mounting frame, 21...Contact body, 22...Connector, P, P=, P2...Shaft, ■...
...Control valve, ■1...Pilot valve, C, curve, oil supply port, d...Pump port,
i...Tank port, A...Working device, D...Model.

Claims (1)

[Scope of claim for utility model registration] A boom 6 that can freely swing up and down has an axis P that is parallel to the swing axis P of the boom 6.
The boom 6, the arm 7, and the work tool 8 are attached with an arm 7 that can swing freely around the boom 6, the arm 7, and the work tool 8. In a work machine configured to remotely control the boom 6, the arm 7, and the work tool 8 by the operation of one model D configured in a scaled-down proportion to the work machine A equipped with a A first link 10 whose base end is pivotably supported around a first pivot shaft 19 a with respect to the base side, and a first link 10 with the first pivot shaft 19 a on the distal end side of the first link 10 . A second link 11 is swingably supported via a parallel second pivot shaft 19b, and is configured to be rotatable around a third pivot shaft 19C attached to the tip of the second link 11. The first pivot shaft 19a is connected to the first link 10, the second pivot shaft 19b is connected to the second link 11, and the third pivot shaft 1
9C are fixed to the operation member 12 so as to rotate integrally with each other, and the contact pieces 21 are fixed to the respective pivot shafts 19a, 19b, 19C, and the working device A Pilot valve v for the control valve ■... which controls the expansion and contraction operation of each hydraulic drive device 9...
1... are located on both sides of the contact pieces 21..., and the respective pivot shafts 19a, 19b
, 19 Mounting frame 20 that is relatively rotatable around the axis of C
Each of the pivot shafts 19 a , 19 b , 19 C is mounted on the . The contact piece 21... is the pilot valve V1...
As it comes into contact with..., its pilot valve■
1... is the link 10.11 which has been rotated.
or the boom 6 of the working device A corresponding to the operating member 12;
In order to operate the control valve V to operate the arm 7 or the work implement 8 in the same direction, the pilot valve ■1
. . . and the control valve V .
, 19 Mounting frame 20 provided around C...
and the respective axes P, P, P2 on the working device A side are:
Each axis P on the working device A side. Each mounting frame 20 on the model D side at a position corresponding to Pl and P2
. . . are interlocked and connected via a connecting fitting 22 . . . so as to rotate in the same direction as the pilot valve V 1 . ·teeth,
A spool 18 that opens the oil supply port C from the pump port d to the control valve V side with the pressing operation of the contact piece 21, between the case 14 of the pilot valve 1 and the spool 18. an actuator 16 that is located at a position where the pump port d is operated a certain amount with the opening of the oil supply port C, and then is switched to close the pump port d to communicate with the oil supply port C and the tank port i; and the mounting frame 20 node. A return spring 17.15 returns the spool 18 and actuator 16 to their original positions within the valve case 14 as the valve case 14 moves away from the contact piece 21 as the valve case 14 rotates. A pilot valve operation structure for a work machine, characterized by a provision for a pilot valve.