JP4006787B2 - Control device for hydraulic drive winch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to braking GoSo location of the hydraulic drive winch for controlling the rotation of the winch drum driven by a hydraulic motor.
[0002]
[Prior art]
Conventionally, a control device for a hydraulic drive winch is provided with a clutch, a negative brake and a positive brake on a winch drum as disclosed in Japanese Patent Publication No. 63-35555,
(I) When the drum is driven, the torque of the hydraulic motor (winch motor) is transmitted to the drum as brake off and clutch on.
(Ii) When the drum is stopped, the clutch is turned off and the negative brake is turned on to hold the drum in a stopped state.
(Iii) At the time of free fall where the suspended load is freely dropped, both the clutch and the negative brake are turned off to make the winch drum free, and the drum rotation speed is adjusted by operating the positive brake pedal while rotating the winch drum according to the suspended load amount. It is configured as follows.
[0003]
[Problems to be solved by the invention]
However, according to this conventional control device, the clutch and the positive brake and their control system are required for free fall, so the device configuration is complicated and the cost is high.
[0004]
In addition, because the speed adjustment of the winch drum during free fall is performed by a friction brake (positive brake), the brake equipment becomes large and heavy, and it is necessary to manage the wear of the friction part, etc. There were drawbacks, such as troublesome maintenance.
[0005]
Accordingly, the present invention provides a control device for a hydraulic drive winch that can eliminate the need for a clutch and brake for freefall.
[0006]
[Means for Solving the Problems]
The inventions of claims 1, to control the winch drum, a variable displacement hydraulic motor for driving the winch drum, and a hydraulic pump as a hydraulic source of the hydraulic motor, the hydraulic fluid supply and discharge to said hydraulic motor Motor capacity control for controlling the capacity of the hydraulic motor in a hydraulic drive winch comprising a control valve, control valve operating means for switching the control valve, and pump pressure setting means for setting the discharge pressure of the hydraulic pump And a free fall command means for commanding a small motor capacity is provided in the motor capacity control means. On the other hand, among the control valve operating means, as the lowering operation means for operating the control valve to the lowering side, The first lowering operation means for lowering and the flow rate of the hydraulic motor exceed the allowable flow rate at the minimum motor capacity. And a second lowering operation means for restricting the flow rate of the control valve so that the excess flow rate exceeding the motor allowable flow rate is returned to the tank when the control valve is operated by the second lowering operation means. A flow control valve is provided .
[0007]
According to a second aspect of the present invention, in the configuration of the first aspect, the apparatus further comprises hoisting pressure detecting means for detecting the pressure of the hoisting pipe line of the hydraulic motor, and the motor capacity control means is detected by the hoisting pressure detecting means. The higher the hoisting line pressure, the more the motor capacity is increased .
[0008]
According to the above Symbol configuration, the rotational speed of the hydraulic motor is inversely proportional to the motor capacity (displacement) at the same flow rate, the rotational speed as the motor capacity is smaller becomes higher, to operate wound under the set conditions of the small motor capacity Thus, the winch drum can be rotated at a high speed.
[0009]
The adjustment of the lowering speed and the lowering stop at this time can be arbitrarily performed by hydraulic control such as controlling the opening degree of the control valve.
[0010]
Thereby, it is possible to perform the same high-speed winding operation (hereinafter referred to as free fall) as in the conventional free fall.
[0011]
Therefore, according to this structure, the clutch and positive brake for free fall and these control systems are unnecessary .
[0012]
In time the hydraulic pump is a hydraulic source for the hydraulic motor, rather than a hydraulic motor only winch, it is customary shared as a hydraulic source of a plurality of actuators.
[0013]
The engine speed changes depending on the total load of the actuators. The change in the engine speed changes the pump flow rate, and the motor flow rate changes.
[0014]
If this happens, the motor flow rate will change at the same control valve position during free fall operation, the motor flow rate will exceed the allowable flow rate when the engine speed increases, and the lowering speed will be too high. There is a risk of causing random rolls.
[0015]
In this regard, according to the above configuration, if the free fall operation is performed by the second lowering operation means, the motor flow rate is reduced to the minimum value of the motor capacity by the flow rate regulating action at the control valve and the surplus flow rate returning action at the flow rate control valve. Within the allowable flow rate.
[0016]
For this reason, a motor flow rate can be maintained appropriately and free fall operation can be performed safely.
[0017]
On the other hand, according to the configuration of claim 2 , when the load is large at the time of free fall and the pressure on the motor winding side is high, that is, when the motor rotation speed becomes too high, the winding capacity pressure is detected to increase the motor capacity. Therefore, the motor rotation speed is automatically reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0019]
Prior to the description of the embodiment, the configuration and operation of the winch control device serving as the basis thereof will be described in order to help understanding of the embodiment .
[0020]
In FIG. 1, reference numeral 1 denotes a winch drum. A rotating shaft 1 a of the winch drum 1 is directly connected to a variable displacement hydraulic motor 2 for winch or connected via a speed reducer, and the winch drum 1 is rotationally driven by the motor 2. The
[0021]
Both the upper and lower pipe lines 3 and 4 constituting the drive circuit of the hydraulic motor 2 are hydraulic pilot switching type control valves 5 having neutral, hoisting and lowering three positions a, b and c. The control valve 5 controls the supply and discharge of pressure oil to and from the motor 2 (driving, stopping, rotating direction and speed during driving).
[0022]
7 is a hoisting-side remote control valve as hoisting-up operation means for operating the control valve 5 in hoisting-up direction. 8 is a lowering-side remote control valve as lowering-side operation means for operating the valve 5 in the lowering side when power is being lowered. The pilot pressure corresponding to the operation amount of both the remote control valves 7 and 8 is sent to the upper and lower pilot ports 5a and 5b of the control valve 5 through the pilot pressure lines 9 and 10.
[0023]
Reference numeral 11 denotes a counter balance valve as a brake valve that generates a hydraulic brake force in the hoisting line 3 during power down rotation, and E denotes an engine that drives the hydraulic pump 6.
[0024]
The motor capacity control means for controlling the capacity of the hydraulic motor 2 will be described.
[0025]
Reference numeral 12 denotes a cylinder as a motor capacity adjustment actuator (hereinafter referred to as a capacity adjustment cylinder) that changes the motor capacity by changing the tilt angle of the hydraulic motor 2, and the motor 12 is reduced in size as shown in the figure. The large capacity is set in the state, and the small capacity is set in the cylinder extended state.
[0026]
The reduction-side oil chamber 12a of the capacity adjustment cylinder 12 is connected to the hoisting line 3 via a hydraulic pilot switching type cylinder control valve (actuator control valve) 13.
[0027]
The cylinder control valve 13 has a large-capacity position A and a small-capacity position B. At the large-capacity position A, the cylinder expansion side oil chamber 12a communicates with the tank T and the capacity adjustment cylinder 12 is reduced (the motor 2 is reduced). Set to large capacity).
[0028]
On the other hand, when the control valve 13 is switched to the small capacity position b, the cylinder 12 is extended by introducing the oil in the hoisting pipe line 3 into the cylinder extension side oil chamber 12a (the motor 2 is moved to the small capacity range). Set).
[0029]
The small capacity side pilot port 13 a of the cylinder control valve 13 is connected to the pilot pressure line 10 of the lowering side remote control valve 8 via a motor capacity switching line 14.
[0030]
The motor capacity switching line 14 is provided with an electromagnetic switching type free fall valve 15 as a free fall command means.
[0031]
The free fall valve 15 is set to the non-operating position (a) during normal operation (except during free fall operation). In this state, the small capacity pilot port 13a of the cylinder control valve 13 communicates with the tank T. The control valve 13 is held at the large capacity position (a) in the figure.
[0032]
From this state, when the free fall valve 15 is switched to the operating position B by the operation of the free fall switch 16, and the lowering remote control valve 8 is lowered in this state, the pilot pressure is changed to the cylinder control valve 13. Is supplied to the small capacity side pilot port 13a and the control valve 13 is switched to the small capacity position B.
[0033]
Thereby, the capacity adjusting cylinder 12 is extended and the motor 2 is set to a small capacity.
[0034]
On the other hand, the large-capacity side pilot port 13b of the cylinder control valve 13 is connected to the hoisting line 3 by the hoisting pressure detection line 17, and when the pressure in the duct 3 increases, the cylinder control valve 13 is moved to the large capacity position i side. Operates to increase motor capacity.
[0035]
Next, a description attached to the pump pressure control means for setting a small pump pressure in a free-fall during operation.
[0036]
Reference numeral 18 denotes a variable relief valve as a pump pressure setting means for setting a pump pressure. A hydraulic pilot type pump pressure switching valve 19 is switched to a spring-side pressure port of the relief valve 18 between a closed position and an open position. And the pump pressure setting valve 20 are connected in series.
[0037]
A pump pressure control line 21 is connected to the pilot port 19 a of the pump pressure switching valve 19, and this pump pressure control line 21 is connected to the output port of the free fall valve 15.
[0038]
With this configuration, when the free fall valve 15 is set to the operating position B, the pilot pressure of the lowering side remote control valve 8 is supplied to the pilot port 19a of the pump pressure switching valve 19, and the switching valve 19 is closed. To open position b.
[0039]
Thereby, the set pressure of the relief valve 18, that is, the pump pressure is set to a value determined by the set pressure of the pump pressure setting valve 20.
[0040]
The pump pressure determined by the pump pressure setting valve 20 is as described above.
It is set to a value that satisfies the relationship of lowering rotational force due to pump pressure and suspension load> drum rotational resistance.
[0041]
In the above configuration, the free fall valve 15 is set to the non-operating position (a) during normal hoisting / lowering operation.
[0042]
In this state, the motor capacity is set to a large capacity and the pump pressure is set to a high pressure, and the hydraulic motor 2 rotates at a speed corresponding to the operation amount (stroke of the control valve 5) of both the hoisting and lowering remote control valves 7 and 8. Then, normal hoisting or lowering operation is performed.
[0043]
Next, when performing the free fall operation, the free fall switch 16 is operated to switch the free fall valve 15 to the operating position b.
[0044]
When the lowering side remote control valve 8 is operated in this state, the motor capacity is set to a small capacity and the pump pressure is set to a low pressure, so that the hydraulic motor 2 rotates at a high speed to perform a free fall operation.
[0045]
At this time, since the opening degree of the control valve 5 changes according to the operation amount of the lowering side remote control valve 8, and the motor flow rate changes, the free fall speed can be adjusted and stopped by the remote control valve 8.
[0046]
Thus, by setting the motor capacity to a small capacity, the hydraulic motor 2 is rotated at a high speed to obtain the free fall function, so that the free fall clutch and positive brake and their control systems are provided. Is no longer necessary.
[0047]
At the same time, since the pump pressure is set to a low pressure, the motor rotation speed does not become excessively high, and an operation close to the original free fall can be performed without causing slack or turbulence of the rope.
[0048]
FIG. 2 shows a winch control device obtained by developing the configuration of FIG.
[0049]
Only differences from the winch control device of FIG. 1 will be described.
[0050]
Difference (1)
In the winch control device of FIG. 1 , the pump pressure is set to a constant value determined by the pump pressure setting valve 20, whereas in this winch control device , the pump pressure control remote control valve 22 is arranged downstream of the pump pressure switching valve 19. A hydraulic pilot type pump pressure setting valve 23 whose set pressure is controlled by the above is provided, and the set pressure of the pump pressure setting valve 23 is changed from the minimum value 0 by operating the pump pressure control remote control valve 22.
[0051]
Difference (2)
An open / close type free fall valve 24 that is switched from the closed position A to the open position B by a free fall switch 16 is provided in parallel with the lowering side remote control valve 8, and the output port of the free fall valve 24 is connected to the capacity switching line 14 and the pump. The pressure control line 21 is connected to the lower pilot pressure line 10 via a shuttle valve (high pressure selection valve) 25.
[0052]
In this configuration, when the free fall valve 24 is set to the open position b, the cylinder control valve 13 is set to the small capacity position b and the motor capacity is set to a small capacity, and at the same time, the output pressure of the free fall valve 24 is controlled. The control valve 5 is set at the lowering position by being supplied to the lowering pilot port 5b of the valve 5.
[0053]
However, if the pump pressure control remote control valve 23 is not operated at this time, the set pressure of the relief valve 18 is close to 0 and the pump discharge oil is in an unloaded state, so the motor 2 does not rotate.
[0054]
When the pump pressure control remote control valve 23 is operated in this state, the pump pressure increases, the motor 2 is driven to the lowering side, and the free fall operation is started.
[0055]
According to this configuration, the pump pressure can be variably controlled in accordance with the magnitude of the load. For example, when the load is large, the lowering rotation speed becomes too high, or conversely, the motor 2 is rotated downward. Free fall operation can be performed more reliably without or without.
[0056]
Further, since the motor capacity, the pump pressure, and the control valve 5 are switched only by operating the free fall valve 24, the free fall operation is performed, so that the free fall valve 24 and the remote control valve 7 are the same as in the first embodiment. Compared with the case where the free-fall operation is performed by operating one valve, the operation is simplified and the risk of erroneous operation is eliminated.
[0057]
In the case of this winch control device , the deceleration / stop during the freefall operation may be performed by the pump pressure control remote control valve 23 or may be performed by the brake action of the counter balance valve 11.
[0058]
FIG. 3 shows a modification of the winch control device of FIG.
[0059]
A remote control type free fall valve 26 is connected in parallel with the lowering side remote control valve 8 instead of the on / off type free fall valve 24 in the winch control device of FIG. The free fall operation is performed when the free fall valve 26 is operated.
[0060]
Also with this configuration, since the free fall operation is performed only by operating the free fall valve 26 as in the winch control device of FIG. 2 , the operation is simplified.
[0061]
Based on the above configuration, an embodiment of the present invention will be described with reference to FIGS.
[0062]
This implementation mode is based on the winch control apparatus shown in FIG.
[0063]
In the winch control device of FIG. 2, by operating the free fall valve 24,
(1) Motor capacity switching
(2) Pump pressure switching
(3) the control valve 5 with respect to that configured to perform all of the switching of, in the implementation mode, performs switching of the motor capacity and the pump by operating the free-fall valve 24, switching of the control valve 5 and the second winding The pump pressure control remote control valve 23 also serves as a lower operation means.
[0064]
That is, the pilot pressure connecting the pump pressure control remote control valve 23 and the pump pressure setting valve 22 while connecting the output port of the free fall valve 24 to each of the pilot ports 13a and 19a of the cylinder control valve 13 and the pump pressure switching valve 19. A branch line 28 is connected to the line 27, and this branch line 28 is connected to the lower pilot port 5 b of the control valve 5 via a shuttle valve 29.
[0065]
Therefore, when the free fall valve 24 is operated, the cylinder control valve 13 is switched to the small capacity position B and the motor capacity is set to the small capacity, and at the same time, the pump pressure switching valve 19 is set to the open position B, By operating the pump pressure control remote control valve 23, the pump pressure is set according to the operation amount.
[0066]
Further, by operating the remote control valve 23, the pilot pressure is supplied to the lowering pilot port 5b of the control valve 5, the valve 5 is set at the lowering position C, and the free fall operation is performed.
[0067]
Here, the hydraulic pump 6 is not dedicated to the winch hydraulic motor 2 but is shared as a hydraulic source of one or more other actuators (not shown).
[0068]
And the rotation speed of the engine E changes with the sum total of the load of each actuator, a pump flow volume changes with the change of this engine rotation speed, and a motor flow volume changes.
[0069]
Therefore, during free-fall operation, the motor flow rate changes at the same control valve position, and when the engine speed increases, the motor flow rate exceeds the allowable flow rate and exceeds the rotation limit of the motor 2, or the unwinding speed becomes too high and is disturbed. There is a risk of winding.
[0070]
Therefore, in the implementation form, in the above-described circuit configuration, the following condition setting, engine speed free fall during operation is to keep the range not exceeding the allowable flow motor flow vary.
[0071]
As shown in FIG. 5, the pilot pressure Ps output by the full stroke of the remote control valve 23 that is used for both the pump pressure control and the control valve 5 is the full stroke of the upper and lower remote control valves 7 and 8. Only the pilot pressure PS that is smaller than the pilot pressure Pf that is output at the time is output, and as shown in FIG. 6, the stroke Ss to the lowering side of the control valve 5 by the pilot Ps is both the upper and lower side remote controllers. The stroke is set to be smaller than the stroke Sf of the valves 7 and 8.
[0072]
Then, as shown in FIG. 7, the maximum passing flow rate (= maximum motor flow rate) Qs of the control valve 5 at the full stroke of the remote control valve 23 is the maximum passing flow rate Qf of the other remote control valves 7 and 8 at the full stroke. The flow rate Qs (hereinafter, referred to as the allowable flow rate) corresponding to the allowable rotational speed when the motor capacity is small is set to be smaller than that.
[0073]
Further, as shown in FIG. 8, in the relationship between the engine speed (minimum value Nmin, maximum value Nmax) and the pump flow rate (minimum value Qmin, maximum value Nmax), a predetermined low value slightly higher than the minimum engine speed Nmin. It is set so that the allowable flow rate Qs can be obtained at the rotation speed Ns.
[0074]
Therefore, as shown in FIG. 9, even if the engine speed exceeds the low speed Ns, the motor flow rate does not increase beyond the allowable flow rate Qs.
[0075]
With this setting, during the free fall operation, the entire pump flow rate is sent to the motor 2 in the low engine speed range (Ns or less), whereas in the high engine speed range exceeding Ns, the pump flow rate Only the allowable flow rate Qs, which is a part, is sent to the motor 2.
[0076]
At this time, in order to return the excess flow rate to the tank T, a flow rate control valve 30 is provided in the pump line as shown in FIG.
[0077]
According to this configuration, since the motor flow rate is suppressed within the allowable flow rate Qs regardless of fluctuations in the engine speed, the motor 2 exceeds the rotation limit due to an increase in the engine speed, or the unwinding speed becomes too high, resulting in random winding. There is no risk of occurrence.
[0078]
Other Embodiments (1) As the motor capacity control means, instead of the capacity adjustment cylinder 12 and the cylinder control valve 13 used in the above embodiment, an electric motor and an electric motor control circuit for controlling the electric motor may be used.
[0079]
(2) as a control valve, in place of the switching valve of the hydraulic pilot type listed above you facilities embodiment, may be used switching valve electromagnetic pilot-type or manual.
[0080]
Here, the control valve operating means is an electric circuit that outputs an electric signal when an electromagnetic pilot type switching valve is used, and an operating lever when a manual type switching valve is used.
[0081]
(3) As for the pump pressure switching valve 19 constituting the pump pressure control means, an electromagnetic or manual switching valve may be used instead of the hydraulic pilot type mentioned in the above embodiment.
[0082]
【The invention's effect】
As described above, according to the present invention, the winch hydraulic motor is set to a small capacity so that the motor can be wound and rotated at high speed to obtain the free fall function. The brake and these control systems are unnecessary.
[0083]
For this reason, the apparatus configuration can be simplified and the apparatus cost can be reduced .
[0084]
Further, motor and over data flow, it is suppressed example Rukoto by the excess flow back action in the flow regulation effect and the flow control valve within the allowable flow rate at the motor capacity minimum value of the control valve.
[0085]
For this reason, a motor flow rate can be maintained appropriately and free fall operation can be performed safely.
[0086]
On the other hand, according to the second aspect of the present invention, when the load is large and the pressure on the upper side of the motor is high at the time of freefall, that is, when the motor rotation is too high, the motor capacity is increased by detecting the upper side pressure. The motor rotation speed automatically decreases.
[Brief description of the drawings]
1 is a hydraulic circuit diagram showing a configuration of the underlying winch control device implementation form of the present invention.
FIG. 2 is a hydraulic circuit configuration diagram showing a winch control device that is an extension of the configuration of FIG . 1 ;
FIG. 3 is a hydraulic circuit configuration diagram showing a modified example of the winch control device of FIG . 2 ;
4 is a hydraulic circuit diagram showing implementation of the invention.
5 is a diagram showing a lever operation amount of the remote control valve in the implementation form, the relation of the outputted pilot pressure.
FIG. 6 is a diagram showing the relationship between the pilot pressure of the remote control valve and the stroke of the control valve.
FIG. 7 is a diagram showing a relationship between the stroke of the control valve and the flow rate through the valve.
FIG. 8 is a graph showing the relationship between engine speed and pump flow rate.
FIG. 9 is a graph showing the relationship between engine speed and motor flow rate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Winch drum 2 Winch hydraulic motor 3 Motor winding upper line 4 Motor lowering line 5 Control valve 6 Hydraulic pump 7 Hoisting remote control valve as control valve operation means 8 Lower winding remote control valve 10 Lowering remote control Valve pilot pressure line E Engine 12 Cylinder constituting motor capacity control means 13 Cylinder control valve 14 Motor capacity switching line 15, 24, 26 Free fall valve as free fall command means 16 Free fall switch as free fall operation means 17 Hoisting pressure detection line as hoisting pressure detection means 18 Relief valve as pump pressure setting means 19 Pump pressure switching valve 20, 22 constituting pump pressure control means 23 Pump pressure setting valve 23 Remote control valve 25 for pump pressure control High pressure selection valve

Claims (2)

A winch drum, a variable displacement hydraulic motor that drives the winch drum, a hydraulic pump as a hydraulic source of the hydraulic motor, a control valve that controls the supply and discharge of pressure oil to and from the hydraulic motor, and the control valve In a hydraulic drive winch comprising a control valve operating means for switching operation and a pump pressure setting means for setting the discharge pressure of the hydraulic pump, motor capacity control means for controlling the capacity of the hydraulic motor, and this motor capacity control means Is provided with a free fall command means for commanding a small motor capacity. Among the control valve operating means, as a lowering operation means for operating the control valve to the lowering side, the first lowering for normal lowering Control so that the flow rate of the operating means and hydraulic motor does not exceed the allowable flow rate at the minimum motor capacity. A flow control valve for returning a surplus flow rate exceeding the motor allowable flow rate to the tank when the control valve is operated by the second roll-down operation unit. control device for a hydraulic drive winch, characterized in that provided. There is provided hoisting pressure detecting means for detecting the pressure of the hoisting line of the hydraulic motor, and the motor capacity control means increases the motor capacity as the hoisting line pressure detected by the hoisting pressure detection means increases. 2. The hydraulic drive winch control device according to claim 1, wherein the control device is a hydraulic drive winch.

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