JPH0358997B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a control device for a torque converter used in a power transmission device in a crane such as a jib crane or a mobile crane.

(Prior art) In the process of crane work, with cranes such as jib cranes and mobile cranes, a suspended load is suspended at a certain height and the position of the suspended load is changed, ie, raised, lowered, or Work often involves turning the aircraft and then raising and lowering it. In this case, with conventional cranes that use a torque converter, once the load is hoisted to a certain height, the brakes are applied to the drum to suspend the load, and then the control lever for controlling the torque converter is used as a guide. Operate to reach the stall point of the torque converter (the point where the output torque of the torque converter becomes equal to the load torque required for lifting the load, and the rotation speed of the output shaft becomes zero regardless of the rotation speed of the prime mover). Once the brakes are roughly adjusted, the load is suspended in the air by loosening the brakes.For this reason, if the control lever is set below the stall point, the load will drop immediately when the brakes are loosened, and the load will instead stall. If the stall point is adjusted above this point, the load will rise, making it unstable and time-consuming to suspend the load, and finding the stall point that is appropriate for the size of the load will require the entire operating range of the operating lever. Since it is extremely inconvenient to have to search for a torque converter, the present applicant previously proposed a torque converter control device as shown in FIGS. 4 and 5. (Japanese Unexamined Patent Publication No. 59-163294) In other words, a multi-plate input adjustment clutch 5 is installed in the power transmission device 6 that connects the prime mover 4 and the hoisting drum 3.
By interposing the torque converter 5 with a, the suspended load P
The load detector 11 provided at the upper end of the jib 2 is engaged in the middle of the lifting wire 8a of the
A includes an amplifier 12 for amplifying the electrical signal detected by the load detector 11, a first converter 13 for digitally converting the amplified signal, an arithmetic unit 14, and an analog converter for converting the output signal from the amplified signal. A second converter 15 connected to the input adjustment clutch 5a of the torque converter is provided, and an amplifier 12' that amplifies the operation signal of the operation lever 7 for controlling the torque converter and the amplified signal is digitally converted and sent to the arithmetic unit 14. A third converter 13' for input is provided, and the signal detected by the load detector 11 and the signal from the operating lever 7 are added or subtracted by the calculator 14 to control the input of the torque converter 5. Cargo P
The stall point is automatically determined according to the weight of the vehicle.

(Problems to be Solved by the Invention) Incidentally, the mass-produced torque converters used in the cranes mentioned above have individual performance variations, and even the same ones may vary depending on the ambient conditions during use (e.g., temperature, torque converter oil cooling water, etc.). water volume and temperature,
Since the performance exhibited is not constant depending on the engine horsepower, etc.), even if the load is the same and the signal from the load detector is the same, the output torque will differ depending on the torque converter used, and the load will be suspended in the air. What should be done rises or falls without being suspended in the air.

In addition, if the operating lever of the above crane is operated in the direction of raising or lowering the suspended load, the suspended load will rise or lower according to the direction of operation, but there is no means to regulate the speed at that time. , the speed will depend on the weight of the suspended load. In other words, suppose that when the neutral position of the control lever is set at the center and speed notches are arbitrarily attached before and after it, and when the lever is aligned with one notch and a load of 100 tons is lifted, the load rises at a speed of 5 m/min. ,
A load weighing half as much, 50 tons, will rise at a speed of 10 m/min if the control lever is in the same notch position.

In this way, the speed changes depending on the weight of the suspended load at the same notch position, which is not only inconvenient but also dangerous.

Therefore, even if there are variations in the performance of the torque converter, this invention can compensate for this and stabilize the performance, and the crane can maintain constant lifting and lowering speed regardless of the size of the suspended load. The purpose is to obtain a control device for a converter.

(Means for Solving the Problems) Based on the above object, the present invention provides a power transmission device that connects a prime mover and a hoisting drum with a torque converter to provide a crane or the like for raising and lowering a load. A load detector is engaged in the middle of the machine, and a main computing unit and first and second sub-computing units connected to it are installed in the operator's cab of the aircraft. The load detector is connected to the load detector through a first analog-to-digital converter and a load signal amplifier installed in the operator's cab, while a second
It is connected to a torque detector disposed halfway along the output shaft of the torque converter via an analog-to-digital converter and a torque signal amplifier, and the second sub-processor is connected to a third analog-to-digital converter in the driver's cab and an operation signal. It is connected to the operating lever via an amplifier, and also connected to the rotation detector connected to the output shaft end via a fourth analog-to-digital converter and a rotation signal amplifier in the driver's cab, and also connected to the rotation detector connected to the output shaft end. is connected to the input adjustment device of the torque converter via a digital-to-analog converter to correct the output torque of the torque converter and to raise and lower the load at a constant speed regardless of the size of the load. .

(effect) This will be explained in detail in the following Examples section.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

Reference numeral 1 denotes a machine body that is rotatably disposed on a base 10, and at its front end, a jib 2 of a required length is pivotally supported by a suspension wire 8b to be able to rise and fall freely. Inside the fuselage 1, there is a hoisting drum 3 equipped with a clutch 3a for engaging and disengaging gears on one side and a brake 3b on the other side, and behind it a prime mover 4 such as an engine or motor, and a multi-plate input adjustment. A torque converter 5 with a clutch 5a is provided, and the output shaft of the torque converter 5 is connected to the hoisting drum 3 via a power transmission device 6 including a belt or chain mechanism and a gear train, and is connected to the driver's cab 1 at the front of the machine.
A lever for operating the drum (not shown) and an operating lever 7 for the input adjustment clutch 5a are provided in the inside of the drum 3, and a lifting wire 8 extending from the winding drum 3 is provided.
a hangs downward through multiple sheaves at the jib head,
A hook block 9 is suspended in the middle, and its tip is connected to the jib head.

In addition, a load detector 11 consisting of a load cell is provided at the head of the jib, and a part of the lifting wire 8a is stretched over the detection roller 11a, and the weight of the load P suspended on the hook block 9 is detected as a voltage. The electric signal is sent to a control device disposed in the driver's cab 1a. The control device is configured as follows.

That is, a main computing unit (computer) 14 and first and second sub-computing units 19 and 20 connected to it on both sides are arranged in the driver's cab 1a.
The first sub-operator 19 includes, on the one hand, a first analog-to-digital converter (hereinafter referred to as an A/D converter) 13 that converts voltage into a digital quantity; and a load signal amplifier 1.
2 to the load detector 11 on the jib 2, and on the other hand to the torque converter 5 via a second A/D converter 18 and a torque signal amplifier 17.
The second sub-operator 20 is electrically connected to a torque detector 16 disposed midway on the output shaft of the controller, and the second sub-operator 20 is connected to the third A/D converter 13' and the operation signal amplifier 12 on the other hand. ', and electrically connected to the rotation detector 21 provided at the output shaft end of the torque converter 5 via the fourth A/D converter 18' and rotation signal amplifier 17'. It is connected to the.

The main computing unit 14 then supplies electricity to the multi-disc input adjustment clutch 5a of the torque converter 5 via a digital-to-analog converter (hereinafter referred to as a D/A converter) 15 that converts the digital signal back into an analog quantity as a voltage. connected.

Note that the operating lever 7 is configured not to transmit an operating signal at a neutral position (the stall point of the torque converter, for example, the center position of the operating range).

Based on the above configuration, during crane work, the clutch 3a of the hoisting drum 3 is disengaged, the brake 3b is loosened, the drum 3 is freed, the lifting wire 8a is let out, the hook block 9 is lowered, and the brake 3b is applied. Once the drum 3 is stopped, the load P is placed on the hook block 9, the clutch 3a is engaged, the brake 3b is released, and the operating lever 7 is moved from the neutral position to a certain position on the upward side (for example, rearward). A voltage signal corresponding to the amount of movement is amplified by the operation signal amplifier 12', and the third A/
The signal is digitally converted by the D converter 13' and input as a (+) signal to the second sub-operator 20.

Furthermore, this is the main arithmetic unit 14 and the D/A converter 15.
is sent to the torque converter 5 side through the
lift up.

Then, the weight of the luggage is detected as a voltage by the load detector 11, and the signal is amplified by the load signal amplifier 12 and sent to the first A/D converter 13.
The signal is converted into a digital signal and input to the first sub-processing unit 19.

At the same time, the torque of the output shaft of the torque converter 5 is detected as a voltage by the torque detector 16 disposed in the middle of the output shaft of the torque converter 5, and the signal is amplified by the torque signal amplifier 17. The signal enters the second A/D converter 18, is converted into a digital signal, and is input to the first sub-operator 19.

Therefore, in the first sub-operator 19, the detector 1
A value proportional to the deviation between the load signal and the actual torque signal is added to the load signal from 1, and the calculated digital signal is input to the main calculator 14. Therefore, the digital signal input from the first sub-computer 19 to the main processor 14 generates the expected torque signal (i.e. stall torque) based on the load signal, regardless of the performance of each torque converter 5. The deviation is repeatedly corrected until a signal suitable for the load is obtained.

On the other hand, the rotation speed of the output shaft of the torque converter 5 is detected as a voltage by the rotation detector 21 provided at the output shaft end of the torque converter 5, and the signal is amplified by the speed signal amplifier 17'. The signal enters the fourth A/D converter 18', is converted into a digital signal, and is input to the second sub-operator 20.

Therefore, in the second sub-computer 20, a value proportional to the deviation between the operation signal and the speed signal is added to the previous operation signal, and the calculated digital signal is input to the main calculator 14. Therefore, the digital signal input from the second sub-computer 20 to the main processor 14 can be operated regardless of the size of the suspended load if the movement position of the operating lever 7 is the same, that is, the operating signal is the same. The speed signal expected by the signal (i.e. the output shaft rotational speed of the torque converter 5)
The deviation is repeatedly corrected until the operation signal is adjusted to correspond to the movement position of the operation lever 7.

Both signals inputted to the main processor 14 in this way are added in the main processor 14, and the added digital signal is again converted into a voltage as an analog signal by the D/A converter 15, and the torque converter 5 input adjustment clutch 5a,
The slip rate is controlled, and the load P rises at a speed commensurate with the amount of movement of the operating lever 7.

Then, when the operating lever 7 is returned to the neutral position when it has risen to a certain height, the operating signal becomes zero, and the output of the second sub-computer 20 is transmitted to the rotation detector 21.
This is a negative (-) signal proportional to the signal from the rotation detector 21, and this becomes one input of the main processor 14. Since a digital signal with the input of Since the signal from the sub-computer 19 becomes equal to the output of the main processor 14 and is sent to the torque converter 5 side, the torque converter 5 is controlled to the stall point corresponding to the magnitude of the load, and the load P is Suspended at a fixed height without brakes. After that, apply the brake 3b and release the clutch 3a.

In this state, to lower the cargo after turning the aircraft 1 at a desired angle, engage the clutch 3a and press the brake 3a.
If b is removed, the load P will automatically become suspended due to the above-mentioned effect. This time, control lever 7
If the is moved to the lower side (forward), a (-) signal corresponding to the amount of movement is transmitted, and this is transmitted through the operation signal amplifier 12' and the third A/D converter 13' to the (-) signal. is input to the sub-processing unit 20 as a digital signal. The signal from the rotation detector 21, which is the other input of the sub-processor 20, is initially zero, that is, the rotation speed of the converter output shaft is zero, so the output of the sub-processor 20 is dependent on the operation signal from the control lever 7. A value proportional to that operation signal is added, (-)
is input to the main processor 14 as a digital signal,
The output of the first sub-processing unit 19, which is the other input to the main processing unit 14, is the same signal amount as in the case of the above-mentioned suspended state, and this is reduced and the output of the first sub-processing unit 19 is
Output from 4. The torque converter 5 is controlled to the lowering state by the output signal, and the load P starts to lower. Then, when the descending speed becomes a constant value, that is, when the (-) signal amount from the rotation detector 21 becomes the same value as the signal amount from the operating lever 7, the output of the second sub-computer 20 becomes the signal from the operating lever 7. This becomes the same as the amount, and this is input to the main arithmetic unit 14.

Here, the output of the main computing unit 14 becomes a constant value, the slip rate of the torque converter 5 controlled by the signal also becomes constant, and the load P descends at a speed commensurate with the amount of movement of the operating lever 7.

Then, when the operating lever 7 is returned to the neutral position after descending to a certain height, the operating signal becomes zero, and the output of the second sub-computer 20 is transmitted to the rotation detector 21.
This is a positive (+) signal proportional to the signal from the first sub-processor 19, and since this becomes one input of the main processing unit 14, the output of the main processing unit 14 becomes a digital signal with the input from the first sub-processor 19 increased. Torque converter 5
Since the torque converter 5 is sent to the side, the descending speed of the torque converter 5 is controlled to be reduced until the speed detected by the rotation detector 21 becomes zero. When the speed detected by the rotation detector 21 becomes zero, the signal from the first sub-computer 19 becomes equal to the output of the main processor 14 and is sent to the torque converter 5, so the torque converter 5 is suspended in the air. controlled by the state.

In the above example, the load detector 11 is installed at the head of the jib 2, but it may be installed at any other location as long as the load can be detected.

(Effects of the Invention) As described above, according to the present invention, variations in the performance of individual torque converters and differences in performance due to ambient conditions even for the same torque converter are always automatically corrected, and the torque converter is able to handle suspended loads. The stall point is automatically controlled according to the weight, and the suspended load can be suspended easily, reliably, and stably. Furthermore, as long as the operating lever is moved the same amount, the suspended load will rise regardless of the weight difference. Since the lowering speed can be kept constant, safe and efficient work can be performed.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the invention. Figure 2 is its plan view. Figure 3 is a block diagram of the control system. FIG. 4 is a side view of the crane according to the previous application. Figure 5 is its plan view. In the diagram, 1... fuselage, 1a... driver's cab, 2... jib, 3... hoisting drum, 3a... clutch, 3
b...brake, 4...prime mover, 5...torque converter, 5a...input adjustment clutch, 6...power transmission device, 7...operation lever, 8a, 8b...
Wire, 11... Load detector, 12, 12'...
Load and operating signal amplifier, 13, 13'...first
and a third A/D converter, 14...main computing unit, 1
5...D/A converter, 16...torque detector, 1
7, 17'... Torque and rotation signal amplifier, 18,
18'...Second and fourth A/D converters, 19,2
0...First and second sub-processing units.

Claims (1)

[Claims] 1 In cranes, etc. that raise and lower loads by interposing a torque converter in the power transmission device that connects the prime mover and the hoisting drum, a load detector is engaged in the middle of the load lifting wire, and the main A computing unit and first and second sub-computing units connected thereto are provided, and the first sub-computing unit detects the load through a first analog-to-digital converter and a load signal amplifier provided in the driver's cab. and a torque detector disposed midway along the output shaft of the torque converter via a second analog-to-digital converter and a torque signal amplifier also provided in the driver's cab,
The second sub-processor is connected to the operating lever via a third analog-to-digital converter and an operating signal amplifier in the operator's cab, and is connected to the operating lever via a fourth analog-to-digital converter and a rotational signal amplifier also in the operator's cab. The main calculator is connected to a rotation detector connected to the end of the output shaft, and the main calculator is connected to an input adjustment device of the torque converter via a digital-to-analog converter to correct the output torque of the torque converter. A torque converter control device characterized by raising and lowering the load at a constant speed regardless of the size of the load.