JPS5998934A - Controller for operation of oil-pressure cylinder - Google Patents

Abstract

PURPOSE:To control the operational speeds of an oil-pressure cylinder by using a system in which output signals from a rocking displacement amount detector and an operational direction detector are put in a controller, and command output signal from the controller is put in an oil-pressure cylinder flow rate regulator. CONSTITUTION:The first detector 11 to send out the detected signal of rocking displacement amount of an arm cylinder 4 is fixed to upside of a boom 1, and the tip of the movable contactor of the detector 11 is rotatably fixed to the downside of the external cylindrical shell of the cylinder 4. The second detector 12 to send out detected signal of the operational direction of an operating lever 18 is provided, and a controller 13 for a micro computer to receive output signals of the detectors 11 and 12 is provided. A direction switch valve 14, an oil- pressure pump 15, a servo cylinder 16 and a switch valve 17 are provided to a flow rate regulator. Command output signal of the controller 13 is put in the switch valves 14 and 17 to adjust the discharge amount of the pump 15 and the operational speed of the cylinder 4 is controlled. The vibration of the cylinder 4 can thus be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation control device for a hydraulic cylinder included in a construction machine such as a hydraulic excavator, and more particularly to an operation control device that can perform good control of the operating speed of a hydraulic cylinder.

FIG. 1 is a side view showing the appearance of a hydraulic excavator as an example of a construction machine equipped with a hydraulic cylinder to which the present invention is applied.

In this FIG. 1, 1 is a boom rotatably connected to the main body, 2 is a zoom cylinder that rotates the poom 1, and 3 is a zoom cylinder that rotates the poom 1.
4 is an arm cylinder that is rotatably connected to the boom 1; 4 is an arm cylinder that rotates the arm 3; 5 is a packet that is rotatably connected to the arm 3; and 6 is a packet cylinder that rotates the packet 5. It is. The above-mentioned pool 1,
The arm 3 and packet 5 constitute the front of this hydraulic excavator, and the poom cylinder 2, arm cylinder 4, and packet cylinder 6 form the hydraulic cylinder that is the object of the present invention in this hydraulic excavator.

The base of the cylinder 2.4.6 is rotatably held by one member, and the tip of the rond is rotatably held by another member. For example, in the case of the arm cylinder 4, its base is rotatably held on the poom 1 via a pin 7, and the tip of the rod is rotatably held on the poom 1 via a pin 9. It can be freely swung against. Further, in FIG. 1, 8 is a pin that connects the pool 1 and the arm 3, that is, a pin that forms the center of rotation of the arm 3.

In this hydraulic excavator, cylinder 2.4
．． By expanding and contracting 5 appropriately, the poom 1 and the arm 3
, the packet 5 rotates to carry out work such as excavating earth and sand.

By the way, in the above-mentioned cylinder 2.4.6, in order to ensure good workability and operability during excavation etc.,
The actuation speed of the cylinder, that is, the actuation speed of the rod is controlled.

For example, near the end of the extension process and contraction process of these cylinders 2, 4, 6, the operating speed up to that point is reduced, thereby creating a buffering effect, and the cylinders 2, 4, 6
, 6, the pins connecting these cylinders, the front member, etc., are suppressed to a minimum.

FIG. 2 is an explanatory diagram showing an example of a conventional hydraulic cylinder operation control device. In this conventional example, the arm cylinder 4 shown in FIG. 1 mentioned above is used as a hydraulic cylinder. In FIG. 2, 10 is a displacement detection means such as a potentiometer, which is fixed on the cylindrical body forming the outer shell of the arm cylinder 4, and has a button to detect the cylinder stroke and output a signal. . Although not shown, the displacement detection means 10 controls the flow rate adjustment means via a predetermined control means.
That is, it is connected to a flow rate adjustment means such as a switching valve that controls the flow rate of the pressure oil discharged from a hydraulic pump that supplies pressure oil to the arm cylinder 4, and is connected to a flow rate adjustment means such as a switching valve that controls the flow rate of the pressure oil discharged from a hydraulic pump that supplies pressure oil to the arm cylinder 4. The flow rate adjusting means is operated, thereby adjusting the flow rate of the pressure oil supplied from the hydraulic pump to the arm cylinder 4, and controlling the operating speed of the arm cylinder 4.

However, in this conventional hydraulic cylinder operation control device, for example, as shown in FIG. Therefore, this displacement detection means 10 has a problem that it is easily damaged by directly receiving the vibration generated in the arm cylinder 4. Also, since the displacement detection means 10 is designed to detect the cylinder stroke, the above-mentioned displacement detection means 10 is A length dimension corresponding to the length dimension of the rod of the cylinder 4 is required, and there is also the problem that it becomes large.

Although not shown, conventionally, as an operation control device for this type of hydraulic cylinder, instead of the above-mentioned displacement detection means 100,
For example, an angle detection means for detecting the rotation angle of the arm 30 and outputting a signal is provided at the position of the pin 8 in FIG.
There is a device that controls the operating speed of the angle sensor, but with such a device, sufficient accuracy cannot be obtained due to the difficulty in manufacturing the angle detection device itself, resulting in a large detection error. There is. When the hydraulic excavator is equipped with an operation control device having such an angle detection means,
There is a problem where damage is likely to occur due to contact with earth and sand during excavation work. Incidentally, such damage may occur particularly when the angle detecting means is attached to the rotating portion of the packet 50 in order to control the operating speed of the packet cylinder 6 shown in FIG.

The present invention has been made in view of the actual situation in the prior art, and its purpose is to provide an operation control device for a hydraulic cylinder that can minimize the influence of vibrations occurring in a hydraulic cylinder and is easy to manufacture. There is a particular thing.

To achieve this objective, the present invention provides a hydraulic cylinder that is held swingably, a hydraulic pump that supplies pressure oil to the hydraulic cylinder, and a flow rate that adjusts the flow rate of the pressure oil discharged from the hydraulic pump. In the device comprising an adjusting means and an operating lever for operating the hydraulic cylinder, the first detecting means detects the amount of rocking displacement of the hydraulic cylinder and outputs a signal, and the first detecting means detects the operating direction of the operating lever and outputs a signal. and a control means for outputting a command signal for controlling the operating speed of the hydraulic cylinder to the flow rate adjustment means based on the signals output from the first detection means and the second detection means. It's Nishide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An operation control device for a hydraulic cylinder according to the present invention will be described below with reference to the drawings.

FIG. 3 is a schematic diagram showing an embodiment of the present invention. In FIG. 3, reference numeral 4 denotes a hydraulic cylinder held in a swingable manner, for example, an arm cylinder included in the above-mentioned hydraulic cylinder 1, and 15 denotes a hydraulic pump that supplies pressure oil to this arm cylinder 4, for example, a variable capacity hydraulic cylinder. A hydraulic pump, 16 is a servo cylinder that controls the discharge amount of the variable displacement hydraulic pump 15, 17 is a switching valve that controls the amount of movement of the piston of the servo cylinder 16, and 14 is between the variable displacement hydraulic pump 15 and the arm cylinder 4. A direction switching valve 18 is installed in the arm cylinder 4 to control the operating direction of the arm cylinder 4.
This is the operating lever that operates the. The above-mentioned directional switching valve 14, servo cylinder 16, and switching valve 17 each constitute a flow rate adjusting means for adjusting the flow rate of pressure oil discharged from the variable displacement hydraulic pump 15.

Reference numeral 11 denotes a first detection means that detects the amount of swing displacement of the arm cylinder 4 and outputs a signal, and 12 denotes a second detection means that detects the operating direction of the operating lever 18 and outputs a signal. As shown in FIG. 4, the first detection means 11 has its main body fixedly mounted on the pool 1, and the tip of its movable contact is a cylinder forming the outer shell of the arm cylinder 4. It is rotatably fixed to the lower part of the body. In FIG. 3, reference numeral 1 and 3 denote control means, which control the flow rate adjustment means, that is, the directional switching valve 14 or the switching valve 17, based on the signals output from the first detection means 11 and the second detection means 2. , outputs a command signal to control the operating speed of the arm cylinder 4. This control means 13 includes, for example, a central processing unit 13a having comparison and calculation functions, an input device 13b,
It is composed of a microcomputer having a storage device 13C1 and an output device 13d.

Next, the arm cylinder 4 implemented in this embodiment
The control operation of the operating speed will be explained.

FIG. 5 is an explanatory diagram of the control principle, and in this diagram,
A indicates the rotation center of the arm cylinder 40 shown in FIG. 4, that is, the center position of the pin 7, and B indicates the rotation center of the arm 30, that is, the center position of the pin 8 shown in FIG. M4. Further, Cm.about.C6 respectively indicate the rotation locus of the center position of the pin 9 in FIG. 4, which is connected to the tip of the arm cylinder 40. The position of the tip of the movable contact of the first detection means 11, that is, the amount of cylinder rocking displacement Y+, is such that the pin 9 shown in FIG.
As pi moves from 1 to C6 to C1 to C6, Y6 to Y,
→Y, →Ys-+Y4→Y, →Y, and so on. In addition,
Even in the explanatory diagram shown in Fig. 5, the house, Y, = Y,, Y, =
C, , C, , C8, and C4 are set so that Y.

Now, when the pin 9 shown in FIG. 4 moves from C3 to C in FIG. The required range is determined, and pin 9 is set to C4.
The period when the arm cylinder 4 moves toward C1 is defined as the range in which the operating speed of the arm cylinder 4 needs to be reduced for a buffering effect in the contraction process of the arm cylinder 4.

Further, suppose that when the tip of the movable contact of the first detection means 11 moves from the position Y shown in FIG.
dT(O), and when the operating amount X of the operating lever 18 shown in FIG.
""-) and Y4 (=Y, ') are stored in advance in the storage device 13C of the control means 13 shown in FIG.

After such settings, a control operation is performed according to the procedure shown in FIG. 6, for example.

That is, first, as shown in step 20, the signal output from the first detection means 11, that is, the cylinder swing displacement amount Y
and the operation lever 18 output from the second detection means 12.
A signal indicating the operating direction of the lever, that is, the lever operating amount X, is read into the central processing unit 13a via the input device 13b of the control means 13 shown in FIG. Next, move on to step 21,
This central processing unit 13a determines whether or not X≧0 is satisfied. When this procedure 21 is satisfied, the arm cylinder 4 is in the extension process and moves to the hand I@22. Next, as shown in step 22, the central processing unit 1
Y stored in storage device 13c in 3a (=Y,
) is called, and it is determined whether Y≦Y, (===Y・) is satisfied. If this judgment is not satisfied, the arm cylinder 4 is in a state where it does not need to reduce its operating speed for the purpose of buffering, and the process moves to step 23.

In this step 23, from the central processing unit 13a to the output device 13
d to the directional switching valve 14 or the switching valve 17.
A command signal indicating this is output. Therefore, the valve opening degree of the directional switching valve 14 and the valve opening degree of the switching valve 17 do not change.

Further, in step 22 above, if Y≦Y, (=y,) is satisfied, the process moves to step 24. Next, as shown in step 24, the central processing unit 13a determines whether dY/dT<O is satisfied.

If this judgment is not satisfied, the arm cylinder 4 is in the process of moving from C3 to C1 in FIG. 5, and therefore does not require deceleration of its operating speed, and the process moves to step 23, where the above operations are performed.

If the judgment in step 24 above is satisfied, the arm cylinder 4 is in the process of moving from C8 to C0 in FIG. Move to. In step 25, the central processing unit 13a outputs the directional control valve 14 via the output device 13d.
Alternatively, a command signal indicating ON is output to the switching valve 17. As a result, the valve opening degree of the directional control valve 14 changes mainly,
The flow rate of the pressure oil supplied to the arm cylinder 4 decreases, or the valve opening of the switching valve 17 changes, and the servo cylinder 1
6 is activated, the discharge amount of the variable displacement hydraulic pump 15 is accordingly decreased, and the arm cylinder 4 is decelerated to a desired operating speed. In this case, a command signal indicating ON may be output from the output device 13d to either the directional switching valve 14 or the switching valve 17 (or a command signal indicating ON may be output to both of them). Good too.

Further, if the judgment in step 21 above is not satisfied, the arm cylinder 4 is in the contraction process and moves to the hand 1 匪 26. Next, as shown in step 26, Y, (=Y, ) is stored in the storage device 13C in the central processing unit 13a.
is called, and it is determined whether Y≦Y, (=Y, ') is satisfied. this,! If F11 disconnection is not satisfied, there is no need to reduce the operating speed of the boom seat 1 and turn 4, and the process moves to hand 1@27.

In this step 27, similarly to step 23, the directional switching valve 14 is turned off via the output device 13d.
A command signal force indicating the output is output.

If the judgment in step 26 above is satisfied, the process moves to step 1 [24] described above. Next, as shown in Figure 24, the central processing unit 13a determines whether dY/dT (:0) is satisfied.

If this judgment is not satisfied, the arm cylinder 1)
is in the process of moving from C0 to C3 in FIG. 5, and is therefore in a state where there is no need to reduce the operating speed.The operation moves to step 23 and the above-mentioned operating force t is applied.

Furthermore, if the judgment in step 24 above is satisfied, the arm cylinder 4 is in the process of moving from C4 force 1 to C6 in FIG. The process moves to step 25, and the above-described operations are performed.

In this way, the arm cylinder 4 is adjusted according to the swing displacement amount Y of the arm cylinder 4 and the operation amount
The operating speed can be well controlled.

In one embodiment configured in this manner, the main body of the first detection means 11 is fixed on the pool 1, so that the influence of vibrations occurring in the arm cylinder 4 is suppressed to a minimum. Furthermore, since the first detection means 11 is constructed of a potentiometer or the like, it is easy to manufacture and can ensure sufficient accuracy. Furthermore, arm cylinder 4
By detecting the slight amount of rocking displacement of the arm cylinder 4, it is possible to know whether or not the operating speed of the arm cylinder 4 is in a state that requires deceleration, without the need to detect the 0 stroke. In particular, when controlling the operating speed of the packet cylinder 6 shown in FIG. In this case, the first detection means 11 is extremely unlikely to come into contact with earth and sand during excavation work, and damage to the first detection means 11 is effectively prevented.

In the above embodiment, when controlling the operating speed near the end of the extension process and the contraction process, the output device 1 of the control means 13
Although similar command signals are outputted from 3d, it is also possible to make the values of these command signals different.

Furthermore, in the above embodiment, the operating speed control of the arm cylinder 4 was described as the speed control associated with the buffering action near the end of the extension process and the contraction process, but the present invention is not necessarily limited to this, and the swing of the arm cylinder 4 is described. Needless to say, desired speed control can be performed at locations other than the vicinity of the terminal end in relation to the amount of dynamic displacement.

Further, in the above embodiment, the arm cylinder 4 and the packet cylinder 6, which are mainly provided in the hydraulic door bell, are used as hydraulic cylinders, but the present invention is not limited to these cylinders 4 and 6, but can be applied to the boom cylinder 2. It can also be applied to hydraulic cylinders included in construction machines other than hydraulic excavators.

As described above, the hydraulic cylinder operation control device of the present invention is configured to control the operating speed of the hydraulic cylinder based on the signal output from the first detection means that detects the amount of rocking displacement of the hydraulic cylinder. Since it is a natural gas, it has the following effects.

(1) The influence of vibrations occurring in the hydraulic cylinder can be suppressed to a minimum, and the durability is superior to that of conventional cylinder stroke detection systems.

(2) Since it is only necessary to detect a small amount of rocking displacement of the hydraulic cylinder compared to detecting the cylinder stroke, the device can be made smaller than the conventional one.

(3) Since the first detection means can be composed of a potentiometer or the like, it is easy to manufacture and can ensure sufficient accuracy.
The detection error can be reduced compared to the conventional one provided with five angle detection means.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the external appearance of a hydraulic excavator as an example of a construction machine equipped with a hydraulic cylinder to which the present invention is applied, and FIG. 2 is an explanatory diagram showing an example of a conventional hydraulic excavator operation control device. , FIG. 3 is a schematic configuration diagram showing an embodiment of the hydraulic cylinder operation control device of the present invention, and FIG. 4 is an explanation showing an example of the arrangement of the first detection means included in this embodiment. FIG. 5 is an explanatory diagram showing the control principle in this embodiment, and FIG. 6 is a flowchart showing an example of the control procedure executed in this embodiment. 2...Boom cylinder, 4...Arm cylinder, 6...Packet cylinder, 11...
...First detection means, 12...Second detection means, 13...Control means, 13a...
Central processing unit, 13b... Input device, 13C.
...Storage device, 13d...Output device, 1
4... Directional switching valve, 15... Variable displacement hydraulic pump, 16... Servo cylinder, 17...
...Switching valve, 18...Operation lever. lI Figure W42 Figure 31! l Figure 4 Figure 5

Claims (1)

[Claims] 1. A hydraulic cylinder held so as to be swingable, a hydraulic pump that supplies pressure oil to the hydraulic cylinder, and a flow rate adjustment means that adjusts the flow rate of the pressure oil discharged from the hydraulic bonder;
A hydraulic cylinder operation control device comprising an operating lever for operating the hydraulic cylinder, including a first detection means for detecting a swing displacement amount of the hydraulic cylinder and outputting a signal, and detecting an operating direction of the operating lever. a second detection means for outputting a signal; and a command signal for controlling the operating speed of the hydraulic cylinder to the flow rate adjustment means based on the signals output from the first detection means and the second detection means. 1. An operation control device for a hydraulic cylinder, comprising: a control means.