JPH0471838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a hydraulic circuit for a hoisting machine that operates a bucket tote using multiple ropes, and more specifically to operations such as hoisting and lowering of the working machine. It is designed to be easy to operate without requiring any skill.

(Conventional technology) In order to hoist and lower a bucket such as a clam shell with a winch such as a crane to excavate, and to remove the soil trapped inside the bucket, two winches must be operated, and the operator is required to operate two winches. It requires advanced technology and skill. That is, conventionally,
The following methods are generally used: (1) using a brake and clutch in combination, and (2) using power hoisting and lowering.
This point will be explained in detail below with reference to FIG.

(1) Method of using a brake and clutch in combination This method uses a combination of a brake and a clutch to show step-by-step a series of operations such as hoisting, digging, raising, and dumping the bucket. In addition, in FIG. 8, a is a crane, b is a bucket, and c is an earth removal vehicle.

First, as shown in Figure 8a, the speed of the support rope is controlled by the brake to lower its own weight.
The tension of the opening/closing rope is controlled by a brake so that it follows the support rope so that it does not loosen and does not generate tension.

Next, as shown in FIG. 8b, sudden brakes are applied to both the support rope and the opening/closing rope.

Next, as shown in FIG. 8c, the tension of the supporting rope is controlled by the brake so that it does not loosen, and it is allowed to fall freely, and the opening/closing rope is wound up.

Next, as shown in FIG. 8d, the tension of the support rope is controlled by the clutch so that it follows the opening/closing rope and is wound up so that it does not loosen and no tension is generated, and the opening/closing rope is wound up.

Next, as shown in Figure 8e, the tension of the supporting rope is controlled by the brake so that it follows the opening/closing rope so that it does not loosen and tension does not occur, and the speed of the opening/closing rope is controlled by the brake. and let it fall freely.

Next, as shown in FIG. 8f, the support rope is stopped by the brake and the opening/closing rope is lowered.

Next, as shown in FIG. 8g, the support rope is wound up, and the opening/closing rope is wound up by controlling the tension so that it follows the support rope and does not loosen or generate tension.

In this method, the driver must perform supporting, opening/closing brake operations and clutch operations at the same time, and requires simultaneous operation of both feet and hands, so the driver requires a high level of skill and uses his/her nerves, resulting in a high level of fatigue. was also very high.

(2) Method using power hoisting and hoisting First, as shown in Figure 8a, the support rope is hoisted down (master), and the opening/closing rope follows the support rope so that it does not loosen and no tension is generated. Lower the winding while controlling it as follows (slave).

Next, as shown in FIG. 8b, both the support rope and the opening/closing rope stop.

Next, as shown in FIG. 8c, the support rope is lowered to the extent that it does not loosen, and the opening/closing rope is rolled up.

Next, as shown in Figure 8d, the support rope follows the opening/closing rope and is hoisted up (slave) while controlling the speed so as not to loosen and to prevent the generation of tension, and the opening/closing rope is hoisted (master). ).

Next, as shown in Figure 8e, the support rope follows the opening/closing rope and is lowered (slave) while controlling its speed so as not to loosen and to prevent the generation of tension, and the opening/closing rope is lowered (slave). Master).

Then, as shown in Figure 8f, the support rope is stopped and the opening/closing rope is lowered.

Next, as shown in Figure 8g, the support rope is hoisted up (master), and the opening/closing rope is hoisted up while controlling the speed so that it follows the support rope and does not loosen and does not generate tension (slave). ).

According to this method, hydraulic cranes are generally designed to have the same drum rotation speed, but in reality, at high speeds, two motors are connected in series, so the previous motor and The speed of the motor in the subsequent stage will be slowed down by the amount of valve relief. Furthermore, since there are variations in the absorption amount of the motor, the speed is not constant, and it is necessary to use both hands to control both speeds as needed. This means that the relationship between master and slave is not constant, which has been a major obstacle when automating the process. In other words, even in the case of power hoisting and hoisting operations, the lever must be operated minutely with both hands in order to maintain the same speed between the support rope and the opening/closing rope, which is troublesome.

Several proposals have been made in an attempt to alleviate such troublesome operations.

JP-A No. 60-52496 discloses a system in which the hydraulic circuits of two winches are made independent, and hydraulic pumps with regulators are connected to each other to equalize the hydraulic pressure, and the speeds of both can be made equal by operating a single lever. However, since there are variations in the rotational speed of the motor due to differences in the absorption amount of the hydraulic motor, the problem has not been completely solved.

Furthermore, Japanese Patent Application Laid-open No. 122698/1983 discloses a system in which the load in the bucket is automatically released when the bucket reaches a certain height. This only automated the setting of the load release height; other operations remained the same as before, and did not relieve the driver from fatigue.

(Problems to be Solved by the Invention) As mentioned above, the conventional device has problems in its operability, and requires skill to operate.
It did not relieve workers from fatigue.

The object of the present invention is to enable all operations such as hoisting and lowering of a bucket hoisting machine to be performed easily without requiring any skill, so that the operator can concentrate on operating only one lever, and to perform precise operations. This allows you to perform operations.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a hydraulic circuit for a hoisting machine having multiple ropes, in which a boost pump is connected to a first hydraulic circuit for driving a bucket support rope winch. By switchably connecting the hydraulic circuit of the motor to the hydraulic circuit of a second hydraulic motor that drives the bucket opening/closing rope winch,
The winch to which the boost pump is not connected is set to the highest speed, so that only the connected winch needs to be operated.

In addition, a bypass circuit is provided in the hydraulic circuit of the first hydraulic motor that drives the winch for the bucket support rope, so that when closing the bucket, the bucket can be lowered by its own weight without having to operate the support rope. The system is configured to reduce the number of operations required by the user.

Further, a means for detecting the rotational speed of the hydraulic motor is provided, and a controller is provided for equalizing the rotational speeds of the two motors based on a detection signal from the detection means, so that the operation can be performed more easily.

(Function) According to the present invention, by selecting the hydraulic circuit of the winch to which the boost pump is connected, the winch of the connected hydraulic circuit has an extra capacity corresponding to the boost pump connected. Since the maximum speed is increased, it is possible to easily follow the boost pump that is not connected.

Therefore, the operator can concentrate on operating only one lever, which is to set one winch to a certain speed and make the winch connected to the boost pump follow it, making the operation much easier and requiring skill to operate. This reduces driver fatigue.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a hydraulic circuit diagram showing a first embodiment of the present invention.

In the figure, 1 and 2 are hydraulic pumps, and the hydraulic pump 1 is connected via a control valve 3 to a hydraulic motor 5 that drives a bucket support rope winch (hereinafter simply referred to as a support winch).
is connected via a control valve 4 to a hydraulic motor 6 that drives a bucket opening/closing rope winch (hereinafter simply referred to as opening/closing winch). The control valves 3, 4 are remotely controlled by proportional pressure reducing valves 7, 8 of the pilot hydraulic circuit shown in FIGS. 2a and 2b. Note that the actual pipe line of the pilot hydraulic circuit is omitted and not shown. A boost pump 9 has a relatively small discharge amount compared to the hydraulic pumps 1 and 2. This boost pump 9 is connected via a switching valve 10 to a hydraulic circuit for a support winch and a hydraulic circuit for an opening/closing winch in a switchable manner. This switching of the switching valve 10 is performed by opening and closing a switch 11 to drive a solenoid of the switching valve 10. 12 is a power source for driving the solenoid. Note that FIG. 3 shows another embodiment of the switching valve 10 described above. This switching valve 13 has a neutral block and is connected to a low pressure relief valve 14. With this configuration, an inexpensive low-pressure pump can be used as the boost pump.

At each stage of operation, the driver connects the boost pump 9 to the hydraulic circuit of the slave winch.
Operate switch 11 so that it is connected. For example, when lowering the bucket, the opening/closing winch becomes the following side, so the switch 11 is left open, and the boost pump 9 is connected to the hydraulic circuit of the opening/closing winch. Then, the winch on the main operation (master) side is set to the highest speed. Next, the following winch may be operated to follow the main operated winch.

Since the side to which the boost pump 9 is connected has a higher capacity, the maximum speed is higher than the other side, so it is easy to follow the other side, and
Since the driver can concentrate on operating one lever, no skill is required.

FIG. 4 is a hydraulic circuit diagram showing a second embodiment of the present invention.

In this embodiment, in addition to the basic configuration of the first embodiment described above, a bypass valve 15 for eliminating the holding pressure of the support rope is provided in the hydraulic circuit of the hydraulic motor that drives the support winch. . This bypass valve 15 is switched by a switch 16.
This is done by driving the solenoid of the bypass valve 15 by opening and closing. 17 is a power source for driving the solenoid.

With this configuration, when the bucket reaches the ground, when the switch 16 is closed, the bypass valve 15 is switched by the operation of the solenoid, and the pressure oil in the hydraulic circuit of the motor 5 escapes to the tank through the bypass valve 15. Therefore, the supporting ropes are not held and the bucket will sink into the soil under its own weight, and at the same time, by winding up the open/close rope, the bucket will scoop loads such as earth and sand into the bucket.

In the first embodiment, at this time, it was necessary to open and close the support rope by winding it down to prevent the support rope from loosening, but in this embodiment, the support rope is held by the bypass valve 15. Loads such as earth and sand can be scooped into the bucket simply by operating the opening/closing rope.
The effort required for the driver's operations is significantly reduced.

As another example of the bypass valve, as shown in FIGS. 5a and 5b, when the pressure of the pressure oil in the hydraulic circuit of the hydraulic motor exceeds a certain value, switch 1 is activated.
It is possible to use bypass valves 18 and 19 which have safety measures such that they do not perform a bypass function even when valves 6 are closed. With this configuration, even if the switch 16 is closed by mistake when winding up the support rope, the bypass valve will not operate, so it is safe.

Note that the parts other than those described above are the same as the configuration shown in the first embodiment, and the explanation will be omitted.

FIG. 6 is a hydraulic circuit diagram showing a third embodiment of the present invention. In this embodiment, a controller 22 is provided, and the controller 22 includes an operating lever 23,
Switch 24 of the switching valve 10 of the boost pump 9
(corresponding to the switch 11 in the above embodiment) and a switch 25 of the bypass valve 15 (corresponding to the switch 14 in the above second embodiment) are connected. Further, the controller 22 is connected to each solenoid of the switching valve 10 and the bypass valve 15 by a control line ₁ and a control line 12. Furthermore, the hydraulic motors 5 and 6 of each winch
The speed detection signals from the speed detectors 20 and 21 are also sent to the controller 22 via the control line _l3 and the control line _l4 .

Electromagnetic proportional pressure reducing valve 2 that drives control valves 3 and 4
6 (corresponding to the proportional pressure reducing valves 7 and 8 of the above embodiment) are connected by a control line so as to be operated by a signal from the controller 22.

By controlling the operation with this controller 22, the load on the driver is further reduced.

The driver first selects the hydraulic circuit to be followed using the switch 24. Next, the speed command value on the main operation side is input to the controller 22 using the operation lever 23 .
The controller 22 outputs a signal to the electromagnetic proportional pressure reducing valve 26 to output a pilot pressure according to the input value. Control valves 3 and 4 send pressure oil from hydraulic pumps 1 and 2 to motors 5 and 6 to drive these motors. Speed detectors 20 and 21 detect the speeds of motors 5 and 6 and send their output signals to controller 22.

The controller 22 outputs a signal to the electromagnetic proportional pressure reducing valve 26 so that the following motor follows the speed of the main operating motor, and controls the control valve so that the speeds of both motors match. Since the boost pump 9 is connected to the follow-up side via the switching valve 10, it has more capacity than the main operation side, and follow-up can be easily performed.

Further, when scooping a load such as earth and sand into the bucket, the switch 25 is closed and the bypass valve 15 is opened to allow the support rope to fall freely under the bucket's own weight, as in the second embodiment.

In this way, the driver only needs to concentrate on speed control on the main operation side, and the operation can be easily performed without requiring much skill.

FIG. 7 is a hydraulic circuit diagram showing a fourth embodiment of the present invention.

In this embodiment, a pressure detector is provided in the motor hydraulic circuit section in place of the motor speed detector of the third embodiment. That is, pressure detectors 27 and 28 and motor 6 are installed on the inlet and outlet sides of the motor 5, respectively.
Pressure detectors 29, 30 are provided on the inlet side and the outlet side, respectively, and these pressure detectors 27, 28, 29, 3
0 is connected to the controller 22 by control lines l ₅ , l ₆ , l ₇ , l ₈ , and these pressure detectors measure the pressure of the pressure oil on the inlet side that enters the motor on the following side and the motor. The pressure on the output side of the driven motor is detected, and the detection signals thereof are taken into a controller 22, which detects the differential pressure of the motor. and,
By controlling this differential pressure, feedback is applied so that the slave motor follows the master motor with low torque and rotates at a constant speed, thereby simplifying the operation. In other words, the controller 22 controls the electromagnetic proportional valve 2 so that the differential pressure between the two pressure detectors on the following side becomes a predetermined low pressure.
6 is controlled.

Below, regarding the operation using this pressure control,
This will be explained with reference to FIG.

First, as shown in FIG. 8a, the support rope is hoisted (master), and the opening/closing rope is caused to fall freely by generating low pressure in the hoisting direction to prevent loosening (slave).

Next, as shown in FIG. 8b, both the support rope and the opening/closing rope stop.

Next, as shown in FIG. 8c, the support rope generates a low pressure in the hoisting direction to allow it to fall freely without loosening (slave), and the opening/closing rope is hoisted (master).

Next, as shown in FIG. 8d, the support rope is wound up (slave) by generating low pressure in the winding direction so that it does not loosen, and the opening/closing rope is wound up (master).

Next, as shown in FIG. 8e, the support rope generates a low pressure in the hoisting direction to allow it to fall freely without loosening (slave), and the opening/closing rope is hoisted down (master).

Then, as shown in Figure 8f, the support rope is stopped and the opening/closing rope is lowered.

Next, as shown in FIG. 8g, the support rope is hoisted (master), and the opening/closing rope is wound up to the extent that it does not loosen by generating low pressure in the hoisting direction.

In this case, since the driver only needs to operate the operating lever 15, it goes without saying that no skill is required as in the previous embodiment.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, the following effects can be achieved.

(1) By making the boost pump switchable between the hydraulic circuit of the first hydraulic motor that drives the winch for supporting the bucket and the hydraulic circuit of the second hydraulic motor that drives the winch for opening and closing the bucket,
The driver can concentrate only on the following side, so compared to conventional systems, it requires less skill to operate.
Moreover, the operation can be performed easily, and the driver's fatigue can be reduced.

(2) The boost pump can be switched between the hydraulic circuit of the first hydraulic motor that drives the bucket support winch and the hydraulic circuit of the second hydraulic motor that drives the bucket opening/closing winch, and
Since a bypass valve is provided in the hydraulic circuit of the hydraulic motor, the support rope is not held by the bypass valve, and loads such as earth and sand can be scooped into the bucket simply by operating the opening/closing rope. , it is possible to significantly reduce the effort required for the driver's operation.

(3) The boost pump is switchably connected to the hydraulic circuit of the first hydraulic motor that drives the bucket support winch and the hydraulic circuit of the second hydraulic motor that drives the bucket opening/closing winch, and The rotational speed of the second motor is detected by a detector, and the controller is used to control the rotational speed of the motor to a constant speed based on the output signal from the detector, so it is easy to perform feedback control. This allows accurate control and simplification of operation.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing a first embodiment of the present invention, Fig. 2 is a configuration diagram of a proportional pressure reducing valve, Fig. 3 is a diagram showing another embodiment of a switching valve, and Fig. 4 is a diagram of a proportional pressure reducing valve. Second
A hydraulic circuit diagram showing an embodiment, FIG. 5 is a diagram showing another embodiment of the bypass valve, FIG. 6 is a hydraulic circuit diagram showing a third embodiment of the present invention, and FIG. 7 is a fourth embodiment of the present invention. An exemplary acupressure circuit diagram, FIG. 8, is a diagram illustrating the various stages of operation of a hoist with multiple ropes. 1, 2... Hydraulic pump, 3, 4... Control valve, 5, 6... Hydraulic motor, 7, 8... Proportional pressure reducing valve, 9... Boost pump, 10... Switching valve, 1
1, 16, 24, 25... Switch, 12... Power source, 13... Switching valve, 14... Low pressure relief valve, 15, 18, 19... Bypass valve, 16...
Switch, 22...controller, 23...operation lever, 20, 21, 27, 28, 29, 30...speed detector, 26...electromagnetic proportional pressure reducing valve.

Claims (1)

[Claims] 1. In a hydraulic circuit of a hoisting machine having multiple ropes, a boost pump is connected to a first hydraulic motor hydraulic circuit that drives a bucket support rope winch, and a second hydraulic motor that drives a bucket opening/closing rope winch. A hydraulic circuit for a hoisting machine having multiple ropes, characterized in that the hydraulic circuit is switchably connected to the hydraulic circuit of a hydraulic motor. 2. In the hydraulic circuit of a hoisting machine with multiple ropes, the boost pump is connected to the hydraulic circuit of the first hydraulic motor that drives the bucket support rope winch and the second hydraulic circuit of the hydraulic motor that drives the bucket opening/closing rope winch. A hydraulic circuit for a hoisting machine having multiple ropes, characterized in that the hydraulic circuit of the first hydraulic motor is switchably connected and a bypass circuit is provided in the hydraulic circuit of the first hydraulic motor. 3. In the hydraulic circuit of a hoisting machine with multiple ropes, the boost pump is connected to the hydraulic circuit of the first hydraulic motor that drives the bucket support rope winch and the hydraulic circuit of the second hydraulic motor that drives the bucket opening/closing rope winch. A controller that is switchably connected and includes rotational speed or torque detection means for the first and second motors, and controls the rotational speeds of the two motors at a constant speed based on an output signal from the detection means. 1. A hydraulic circuit for a hoisting machine having multiple ropes, characterized in that the hoisting machine is provided with: 4. The hydraulic circuit for a hoisting machine having multiple ropes according to claim 3, wherein the rotational speed detection means of the motor is a speed detector provided in the motor. 5. The hydraulic circuit for a hoisting machine having multiple ropes according to claim 3, wherein the torque detecting means of the motor is a pressure detector provided on an inlet side and an outlet side of the motor.