JPS5986590A - Generator for critical signal of state of stoppage in hydraulic cylinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stop state danger signal generating device for a hydraulic cylinder.

Hydraulic cylinder FD to which the present invention is applied (FP has a pressure chamber on the long operation side and a pressure oil chamber on the contraction operation side, and is controlled by a full hydraulic control device for supplying and discharging hydraulic oil to these two oil chambers and stopping the supply and discharge. This is a hydraulic cylinder that can be telescopically driven and stopped while carrying a load. This will be explained in detail based on FIG. 1.

In FIG. 1, the hydraulic cylinder 1 is comprised of a cylinder 2 piston rod 31 and a piston 4 fixed to the base end of the piston rod 3 and slidably inserted into the cylinder 2 in an oil-tight manner. The piston 4 divides the cylinder 2 into a full extension side pressure chamber 5 and a contraction side pressure chamber 6. A hydraulic control device 7 that controls the supply and discharge of hydraulic oil to and from the extension operation side pressure oil chamber 5 and the contraction operation side pressure oil chamber 6 of the oil field cylinder 1 controls the supply and discharge of hydraulic oil to the extension operation side pressure oil chamber 5 and the contraction operation side pressure oil chamber 5. A supply/discharge circuit 8 and a supply/discharge circuit 9 connected to the supply/discharge circuit 6. Supply circuit 1 connected to hydraulic pressure generator 10
1. and a discharge circuit 13 connected to the oil tank 12. In the case of FIG. 1, this supply/discharge control device 7 is composed of a four-way three-position oil pressure removal switching valve 14 and a holding pulp 15 provided in the supply/discharge circuit 8. The holding pulp (or counterbalance box) 15 allows hydraulic oil to freely flow from the four-way three-position hydraulic pressure removal switching valve 14 to the hydraulic cylinder 1, but in the opposite direction to the supply/discharge circuit 9.
It is foggy so that it is only allowed when the oil pressure inside rises.

F is the load f' carried by the hydraulic cylinder 1 (the hydraulic cylinder 1 is driven to extend by operating the hydraulic control device 7 to the four-way n=position hydraulic switching valve 14'rI position;
By operating the four-way three-position hydraulic pressure removal switching valve 14'kI [position, it will reduce the drive, and by setting the four-way three-position hydraulic switching valve 14 to the center position 0, it will stop with the load Fi being carried. ing.

If this type of hydraulic cylinder 1 is fully extended and stopped for a long time, it may suddenly contract. That is, the oil temperature in the extension operation side pressure oil chamber 5 on the side that carries the load Pi of the hydraulic cylinder 1 is transmitted to the cylinder 2 or the cylinder 2 and released to the outside air.

As the oil temperature gradually decreases, the volume of the hydraulic oil filled in the extension side pressure oil chamber 5 decreases.The decrease in the volume of the hydraulic oil causes the oil pressure in the extension side pressure oil chamber 5 to decrease. The load carrying force due to the hydraulic pressure in the extension operation side pressure oil chamber 5 (pressure of the hydraulic oil in the extension operation side pressure oil chamber 5 x pressure receiving area of the piston 4) is completely reduced.On the other hand, the piston 4 of the hydraulic cylinder 1, the cylinder 2 and the piston rond. 3 and the cylinder 2, or the mechanical parts where the hydraulic cylinder 1 is installed (friction exists in this area, so even if the load-carrying force due to hydraulic pressure decreases somewhat as described above, the load due to this friction will be reduced). The carrying capacity fully covers the reduction in load carrying capacity due to hydraulic pressure.

Load F? The hydraulic cylinder 1 is held in a stopped state, but when the load-carrying force due to hydraulic pressure decreases beyond a certain level, the load-carrying force due to friction is no longer able to compensate for the load-carrying force.
This will lead to a rapid reduction in size. Is this kind of phenomenon something that occurs suddenly? It was extremely dangerous because it was unpredictable.

The present invention detects in advance that the hydraulic cylinder is suddenly moved by the load as described above in a stopped state where the hydraulic cylinder is stopped while carrying a load, and generates an electric output signal. It is an object of the present invention to provide a device for generating a stop condition danger signal in an oilfield cylinder.

The electrical signal obtained by the stop state danger signal generating device for a hydraulic cylinder of the present invention is used for activating or lighting a warning buzzer or warning lamp, or the oil chamber (on the side that carries the load of the hydraulic cylinder). This signal is used as a command signal for replenishing hydraulic oil to the extension operation side pressure oil chamber or the contraction operation side pressure oil chamber.

The stop state danger signal generating device for a hydraulic cylinder according to the present invention has an extension operation side pressure oil chamber and a contraction operation side pressure oil chamber, and a full hydraulic control device for supplying and discharging hydraulic oil to both oil chambers and stopping the supply and discharge. With proper control, the extension m IF51. This is a stop state danger signal generating device for a hydraulic cylinder that can stop while carrying a load as well as a load in both oil chambers of the hydraulic cylinder. An oil temperature detector that detects the entire oil temperature of the oil on the supporting side, responds to the oil temperature, and outputs the fc electric signal as a total actual value signal, a memory command signal input device,
and the storage command signal from the storage command signal input device □
The actual value signal from the oil temperature detector when the oil temperature sensor is received is memorized, and the relationship between this stored value and the actual value signal from the oil temperature detector is continuously created by an optical illusion. Does it consist of an arithmetic unit configured to generate an electrical output signal when the value decreases by more than a predetermined value? This is a characteristic feature.

Is this invention the following? An embodiment implemented in the hydraulic cylinder shown in FIG. 1 will be explained in detail based on the drawings from FIG. 2 onwards. The reference numerals 1 to 15 and F used in FIG. 1 and described above have the same meanings in the following explanation, so the explanation thereof will be omitted entirely. −′
-', Fig. 2 (shown below) 16 detects the oil temperature of the oil chamber 5 on the side that carries the load, that is, the pressure oil chamber 5 on the extension operation side, of the two oil chambers 5 and 6 of the hydraulic cylinder 1. This is an oil temperature detector that outputs an electrical □ signal in response to temperature as an actual value signal.The actual value signal that is output by the oil temperature detector 16 is:

The signal is input to an arithmetic unit 17, which will be described later. 18 is a computing unit 17
This is a storage command signal input device for storage command Kanayama. Said mu
The device 17 is configured as a first-order device. Namely.

An A/D converter 19 that converts the actual value signal t from the oil temperature detector 16 into a digital electrical signal. The A/D converter 19 and the storage command signal input device 18 (this storage command signal generator 18 includes two resistors 51 and 52 directly connected between the poles of the direct 24V power supply 500, and both resistors 51 and 52). resistance 5175
The switch 53 is connected to the metal so that the potential of the connection part between the resistors 51 and 52 is set to 2 OV, and the switch 53 is connected to the metal.
By completely disconnecting the resistors 51 and 52, the potential at the connection portion of both the resistors 51 and 52 can be set to 3V. A connecting portion between the resistors 51 and 52 of the storage command signal input device 18 is connected to a computing device 17, which will be described later. ) signal from? Input port 21 connected to common bus 20, C! connected to common bus 20! I) U (Central Processing Unit)22. ROM (IJ-only memory) 23
．． A RAM (Random Access Memory) 24 and an output port 25 constitute a TG.

Then, the OP key 22 executes the program stored in the RAM 24. Execute. This calculation is.

This is executed while the storage command signal from the storage command signal input device 18 is being input to the input port 21. When the switch 53 of the storage command signal input device 18 is turned on and the storage command signal of ○■ is input from the storage command signal input device 18 to the input port 21 of the arithmetic unit 17, (n)
1! At that time (memory command signal 7'l; 1 interval after input), the PU 22 receives the actual value signal from the oil temperature detector 16 which is inputted to the input port 21 & here via the A/D converter 19. A command is issued to store it in the ROM23.

In accordance with this command, the ROM 23 stores an actual value signal from the oil temperature detector 16 at the time (instantaneous) when the operation command signal is output from the memory command signal input device This is the value in response to the oil temperature of No. 5.

) is stored as a memory value. Next, 0PU22 is RO
M24G has the above-mentioned stored value.

The actual value signal from the oil temperature detector 16 that is input to the input port 21 via the AD converter 19 is continuously compared.

The comparison result is input to the input port 21 via the A/D converter 19.
When the actual value signal from the oil temperature detector 16, which is input to the oil temperature sensor 16, decreases from the stored value by a predetermined value or more, an electric signal is output from the output port 25. The above predetermined value is.

The oil pressure in the oil chamber (extension operation side pressure oil chamber) 5 of the piece that carries the load changes from the oil pressure (hereinafter referred to as initial pressure) at π when the hydraulic cylinder 1 is fully extended and retracted and stops carrying the load Ft.
Hydraulic cylinder 1 is fully loaded? ? The minimum pressure required to safely stop the product while it is supported (hereinafter referred to as the minimum required pressure).

). This corresponds to the decrease in oil temperature (hereinafter referred to as allowable reduced temperature) in the oil chamber 5 on the side that carries the entire load (extension operation side pressure oil chamber). Specifically, the load on oil field cylinder 1? When the temperature of the oil chamber 5 on the supporting side drops by the allowable reduction temperature, the A/D converter 1
This is the fluctuation of the actual value signal of the oil temperature detector 16 inputted through the input terminal 9. This predetermined value is 1 and is stored in the ROM 23 in advance. The stop state danger signal generating device for a hydraulic cylinder according to the present invention includes an oil temperature detector 16. It is composed of a storage command signal input device 18 and an arithmetic unit 17. Reference numeral 26 denotes a relay that operates based on the electrical output signal output from the output port 25 of the computing unit 17.
When activated, switch 2 is fully closed.

28 is a buzzer that operates when the relay switch 27 is opened.

Next, I will explain the effect of Q. After operating the oilfield drive device 7 and driving the hydraulic cylinder 1 to expand and contract, the load F is applied to the hydraulic cylinder 1.
When it comes to a complete stop while carrying a
Memory command signal input device 18 in stop state danger signal generator A? The memory command signal is input to the full input port 21 by operation. Then, when the storage command signal is input, the arithmetic unit 17 outputs the input port 21 (*) via the A/D converter 19.
The input output signal from the oil temperature detector 16 is stored as a memory value.

Thereafter, the computing unit 17 continuously monitors the stored value and the actual value from the oil temperature detector 16 that is input to the input port 21 via the A/D converter 19, and compares the stored value with the actual value. When the value decreases by a predetermined value or more, the output port 25 outputs the full electric signal. This comparison operation by the calculator 17 is continuously performed while the storage command signal is being input from the storage command signal input device 18 to the input port 21. Arithmetic unit 17
When an electrical signal is output from the output port of t'L7c,
The oil temperature in the oil chamber on the side that carries the load 11''7 of the hydraulic cylinder 1, that is, the extension operation side pressure oil chamber 5, and the memory command signal input device 1
It will be understood from the above description that this is the time when the temperature has been reduced by a predetermined value, that is, the allowable reduction temperature since the time when 8 was operated.

-j In other words, the output of the electric transmitter from the output port 25 of the calculator 17 decreases as the oil temperature in the oil chamber W that carries the load Fk of the hydraulic cylinder 1, that is, the pressure oil chamber 5 on the extension operation side decreases, and the Is the top one hydraulic cylinder 1? Has the load F become dangerously low to keep it stopped? means. The electrical output signal of the arithmetic unit 17 output in this way is transmitted to the relay 26
Activate relay switch 27? Make M. and,
Closing of the relay switch 27 activates the buzzer 28', which issues a warning signal 7 to the operator.

When the operator receives this warning message, the operator operates the four-way three-position hydraulic switching box 14k to the 1 position to supply pressure oil from the hydraulic generator 1° to the extension operation side pressure oil chamber 5 of the hydraulic cylinder 5 'Tt''L, is good.

In the above embodiment, the buzzer 28 is activated by the electrical output signal of the computing unit 17, but as shown in FIG. 3, the buzzer 28 is operated by this electrical signal.

A quantitative replenishment device 29 for replenishing a constant amount of oil to the load carrying 9111 oil chamber 5 of the hydraulic cylinder 1 may be operated. That is, in FIG. 3, the quantitative replenishment device 29 is
Measuring cylinder 32 with piston/rod side oil draft 3o and non-piston Rondo 4 oil chamber 31; its P port) 33'!
r When connected to the non-piston rod side oil chamber 31 of the metering cylinder 32, it is a tank port) 34 all 1ttft 1 position connected to the piston rod side oil chamber 3o of the cylinder 32, and its P boat 33 pistons of the metering cylinder 32 An oil passage 35 connected to the rond side oil chamber 30 and to the load carrying side oil chamber 5 of the hydraulic cylinder 1 is connected to the metering cylinder 32
A solenoid-driven replenishment control valve 36 having a position ■ connected to the non-piston rod side oil chamber 31; and a pressure source 3
7 and the 1 position where the P boat 33 tray of the replenishment control valve 36 is shut off and these? ■Solenoid-driven metering control valve 38 with all positions connected? We are prepared. The replenishment control valve 36 and the metering control valve are operated to position (2) by energizing the solenoids 36' and leeches.

Both the solenoid 3C of the supply side' control valve 36 and the solenoid 38' of the metering control valve 38 are controlled to be energized by the switches 27 and 27' connected by the electrical output signal of the computing unit 17. For this reason, the arithmetic unit 17
When an electrical output signal is output from the oil source 37,
The oil.

Planned control measure 38. The oil passes through the replenishment control 136 and flows into the piston rond side oil i30 of the metering cylinder 32, moving the piston to the left in the figure. This clock amount cylinder 3
The filling oil in the non-piston rod side oil chamber 31 of No. 2) is supplied to the load carrying side oil chamber 5 of the hydraulic cylinder 1 through the supply control 9P36 and the entire oil passage 35. 39 is a switch that is connected when the piston of the measuring cylinder 32 moves to the left end in the figure (when this switch 39 is connected, the switch 40 connected in series with the switch 53 of the memory command signal input device 18 is immediately disconnected). Join me, this switch 3
When 9 goes from disconnected to connected, is this the predetermined time?
The timer 41 is turned on so that the switch 53 is connected.
It is associated with the switch 40 via. 42 is
This switch is turned off only when the piston of the measuring cylinder 32 is at the right end in the figure.This switch 42 is connected to the power supply 50 (! It is interposed between the solenoid of the control 9P38. When the piston of the meter-it cylinder 32 moves to the left end in the figure as described above, the switch 39 is connected and at the same time the switch 40 is disconnected. As a result, the memory The signal generated by the command signal generator 18 becomes &4V, and the storage command signal disappears.The disappearance of the storage command signal causes the entire operation of the arithmetic unit 170 to be stopped, and the arithmetic unit 17 stops its electric output signal. Switches 27 and 27' accordingly
is cut off, and the replenishment control 9f36 is reset to the 1 position. However, the solenoid 38' of the metering control valve 38
The switch 42 (as mentioned above, this switch 42 is a switch that is closed only when the piston of the needle cylinder 32 crosses the right end in the illustration, and is closed at this point) is closed. ■The position is maintained because of this.

Therefore, the pressure oil from the hydraulic source 37 is transferred to the metering control valve 38. The oil flows through the supply fblJ control tank 36 into the non-piston rond side oil supply 31 of the measuring cylinder 32 and moves the piston of the measuring cylinder 32 to the right.

Simultaneously (piston rond fflt1 of measuring cylinder 32
mffis.

The oil is discharged through the tank port 34 of the replenishment control valve 36. When the piston of the measuring cylinder 32 reaches the right end,
The switch 42 is turned off and the metering control valve 38 is reset to the position (2). In this way, the quantitative replenishment device 29 completes the replenishment preparation. Note that when the piston of the metering cylinder 32 begins to move to the right as described above, the switch 39 is closed.
Due to the action of the timer 41, the switch 40 is activated by the fixed amount replenishing device 2.
No contact will be made until 9 completes preparations for replenishment. When the switch 40 is connected after the quantitative replenishment device 29 has completed the replenishment preparation, the storage command signal generator 18
Two storage command signals are issued, and the arithmetic unit 17 stores the actual value signal from the oil temperature detector 16 at this point and starts full functioning.

When the oil temperature of the load carrying side oil amount 5 of the hydraulic cylinder 1 drops and replenishment becomes necessary (in this case, replenishment is performed again as described above).

The hydraulic cylinder to which the stopping state danger signal generating device for a hydraulic cylinder of the present invention is applied is the one described at the beginning, and in the above embodiment, this hydraulic cylinder is operated under the conditions explained at the beginning. However, are there any specific examples of uses of the lateral pressure cylinder to which the present invention is applied? Let me explain. It is a hydraulic cylinder for extending and retracting the boom of a crane. As shown in FIG. 4, the telescopic boom 54 of the crane includes an outer boom 55 on the proximal end, an inner boom 56 at the tip telescopically inserted into the outer boom 55. and a hydraulic cylinder 1' which is interposed between the outer boom 55 and the inner boom 56 and drives and stops the inner boom 56 in relation to the outer boom 55. This telescopic boom 54 is connected to a hydraulic cylinder 57 for raising and lowering the boom.
The elevation is operated by. For crane work, telescopic boom 5
This is done by suspending a load W'6 from the tip of the cylinder 4, extending, retracting and stopping the 54 telescopic booms, and operating the entire boom. However, since this type of hydraulic cylinder 1' is extremely long, However, the sudden contraction due to a drop in oil temperature or oil leakage in the extension side pressure oil chamber was extremely dangerous. When the present invention is adopted in this hydraulic cylinder 1', a great effect can be expected.The special feature is the telescopic boom 54 of the crane as described above.

As the lifting angle of the telescopic boom 54 changes, the outer pool 5
5 and the fitting portion of the inner boom 5 (frictional force that attempts to prevent (q3 retracting movement of the telescopic boom 54) changes. And this tendency becomes larger as the telescopic boom 54 is lowered. This is obvious if we consider that the direct pressure acting on the fitting portion due to the load W increases.In other words, 'jn'.

9. The more the telescopic boom 54 is lowered, the greater the load-carrying force due to friction becomes.9. Even if the oil pressure in the extension side pressure oil chamber of the hydraulic cylinder 1' is significantly reduced, the hydraulic cylinder 1' can still remain in a stopped state.

That is, the allowable reduction temperature of the hydraulic cylinder 1' increases. In this way, in a device where the load-carrying force due to friction fluctuates rapidly, the value responsive to the allowable reduction temperature stored as a predetermined value in the RAM 24 of the calculator 17 is changed in accordance with the boom's heave angle. It is proposed as a further development of the present invention to do so. In this case, it is possible to suppress the generation of the electrical output signal of the stop state danger signal generating device # in the oil discharge cylinder according to the present invention to the minimum necessary level.

In the end, since the Kinai BA is configured and operates in the manner described above, it will be possible to detect in advance that a hydraulic cylinder that is in a stopped state while carrying a full load is suddenly driven by a load. Since it outputs the full electrical signal, it has an extremely large effect on ensuring safety.

[Brief explanation of the drawing]

FIG. 1 and FIG. 4 are explanatory diagrams of a hydraulic cylinder to which the stop state danger signal generation device for a hydraulic cylinder of the present invention is applied;
FIGS. 2 and 3 are explanatory diagrams of an embodiment of a stop state danger signal generating device for a hydraulic cylinder according to the present invention. Extension action side pressure oil chamber; 5° Reduction action side pressure oil chamber; 6° Oil field control device; 7° Output cylinder; 1° Memory command signal input device; 18° Liquid calculator: 17° Oil temperature detector; To 1

Claims (2)

[Claims] (1) It has an extension side pressure oil chamber and a contraction side pressure oil chamber. By controlling the supply and discharge of hydraulic oil to and from these internal oil chambers by a full-hydraulic control device, hydraulic cylinders that can be stopped while carrying a load as well as telescopic drive (stop state danger signal in this an oil temperature detector which is a generator and detects the oil temperature of the oil chamber on the side that carries the load among the inner oil chambers of the hydraulic cylinder and outputs an electric signal in response to the oil temperature as an impingement value signal; A memory command signal input device, and all the actual value signals from the oil temperature detector when receiving the memory command signal from the memory command signal input device, and this memory value and the actual value from the oil temperature detector. an arithmetic unit configured to continuously monitor all signal relationships and generate an electrical output signal when the actual value decreases by more than a predetermined value with respect to the stored value;
A stop state danger signal generating device for a hydraulic cylinder, characterized by comprising: (2) A stop state danger signal generating device for a hydraulic cylinder according to claim 1, wherein the hydraulic cylinder is a hydraulic cylinder for extending and retracting a telescopic boom of a crane.