JPH0127958B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to 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, and the present invention relates to 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. The purpose is to control operations efficiently and safely.

Figures 1 and 2 show recent cranes that use an engine or motor as the prime mover (a), and a torque converter (t) with a multi-disc input adjustment clutch (s) is interposed in the power transmission device (m) to suspend the crane. It is designed to convert the input torque from the prime mover a according to the weight of the load p and transmit it to the hoisting drum d.

Then, the prime mover a is started, the clutch c of the hoisting drum d is disengaged, the brake b is released, and the drum d is
Free and play w, hook block f
, apply brake b to temporarily stop drum d, apply load p to hook block f, first engage clutch c and release brake b, then increase the output rotation of torque converter t to raise load p to a certain height. A so-called crane operation is performed in which the cargo P is hoisted up to the ground, and then the aircraft F is rotated to lower the cargo P to the destination location.

In the process of the above work, the load p lifted to a certain height is lifted higher or lowered, or after the aircraft F turns with the load p lifted to a certain height, the load p is lowered. When the suspended load p is already temporarily suspended in the air, as in the above case, there is a need to change its position.

Conventionally, this is done as follows.

That is, when the load p is lifted to a certain height, the load p is suspended in the air by applying the mechanical brake b, and then the torque converter control lever l is operated as a guide to raise the torque converter t.
At the stall point of
Next, the mechanical brake b is released, the load p is suspended in the air without the brake, and the load p is raised or lowered.

In this case, the driver manually operates the operating lever l, and transmits the operating amount to the torque converter t by oil pressure, pneumatic pressure, or voltage, changes the slip rate of the input adjustment clutch s, and controls the input of the prime mover a. Although the torque is controlled, the control of the input adjustment clutch s is performed as a guideline, so if the operating lever l is set below the stall point, when the brake b is released, the load p will start to fall and the reverse stall point will be reached. If the above conditions are met, the load p will rise immediately when brake b is released, and it will be extremely difficult to remove the brake, that is, to make the load p hang in the air. It is necessary to search over the entire operating range of the lever, which takes some time, is complicated when there are many types of cargo, has poor work efficiency, and is not good in terms of safety.

Therefore, this invention was devised to eliminate the above-mentioned drawbacks, and provides a control device that is easy to operate, efficient, and ensures safety. In a hoisting device, a hoisting device is provided with an operating lever that controls the hoisting operation by interposing a torque converter in the hoisting device, and the operating lever controls the input of the torque converter to raise and lower a load and suspend the load. The operating lever is equipped with a load detector that measures the weight of the load and transmits it as an electrical signal, and the operating lever transmits changes in the amount of operation as an electrical signal of opposite positive and negative amounts in the hoisting and lowering directions, and The system is configured so that the amount of position transmission is zero, converts both the electrical signal transmitted by the load detector and the electrical signal transmitted by the operating lever into digital quantities, receives them, and adds both electrical signals. and converts the electric signal of the addition amount transmitted from the computer into an analog value to control the input of the torque converter, and performs hoisting and lowering when the operating lever is in the positive and negative positions, and when the operating lever is in the neutral position. This is characterized in that the torque converter stalls, causing the load to suspend in the air.

Embodiments of the present invention will be described below with reference to FIGS. 3 and 4. Reference numeral 1 denotes a machine body that is rotatably arranged on a base 10, and as usual, a jib 2 of a required length is attached to a suspension wire 8b at its front end.
The machine body 1 is provided with 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.
Behind it is a prime mover 4 such as an engine or motor,
A torque converter 5 with a multi-plate input adjustment clutch 5a is provided, and the torque converter 5 is connected to the hoisting drum 3 via a power transmission device 6 including a belt or chain mechanism and gears, and is connected to the driver's cab 1a at the front of the machine. A lever for operating the drum and an operating lever 7 for the input adjustment clutch 5a are provided inside, and a lifting wire 8 extending from the hoisting 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.

By the way, in this invention, a load detector 11 consisting of a load cell is provided at the head of the jib 2,
A part of the lifting wire 8a is hung on the detection roller 11a, and a load signal amplifier 12 electrically connected to the load detector 11 and amplifying the voltage as a pressure signal is installed in the operator's cab 1a of the machine body 1. The first step is to convert the voltage into a digital quantity to make it easier to calculate.
an analog-to-digital converter (hereinafter referred to as A/D converter) 13, a computer 14, and a second digital-to-analog converter (hereinafter referred to as D/A converter) that converts the digital signal output from the computer 14 back into voltage as an analog quantity. ) 15 are sequentially provided, and this D/A converter 15 is electrically connected to the input adjusting clutch 5a of the torque converter 5, and is also connected in parallel to the above control circuit with an operating control circuit for controlling the torque converter. A lever signal amplifier 1 that is electrically connected to the lever 7 and amplifies the operation signal.
A third A/D converter 13' is provided which converts the lever signal 2' and its amplified lever signal into a digital quantity and sends it to the computer 14.

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).

In order to control the input adjustment clutch of a torque converter by an electric signal, conventionally, an electromagnetic proportional pressure regulating valve (for example, an electric modulating valve manufactured by Twin Disk Inc. of the United States), which is commonly sold for this purpose, is used.
use.

To briefly explain how it is used, the input adjustment clutch is a hydraulic multi-plate clutch, and the input torque of the torque converter is adjusted by adjusting the degree of engagement of the clutch.The hydraulic control circuit for this purpose is Contains an electromagnetic proportional pressure regulating valve,
This valve is equipped with a pilot valve that controls the drain by electrical signals.

This pilot valve consists of an electromagnetic coil, a plunger, and a regulating orifice, and the plunger is moved by changes in the magnetic field caused by increases and decreases in electric signals, that is, signals in the (+) direction or (-) direction, and is composed of the plunger and its seat. The orifice is adjusted. By adjusting the orifice, the drain of the pressure oil passing through the electromagnetic proportional pressure regulating valve is adjusted, and the pressure oil sent to the input adjustment clutch is adjusted, thereby adjusting the degree of engagement of the clutch.

Based on the above configuration, when performing crane work, the clutch 3a of the hoisting drum 3 is disengaged as described above, the brake 3b is loosened, the drum 3 is freed, the lifting wire 8a is let out, and the hoisting drum 3 is released. 9, apply the brake 3b, stop the drum 3, apply the load P to the hook block 9, engage the clutch 3a, release the brake 3b, and move the operating lever 7 from the neutral position to the raised side (for example, the rear side). ), the load p will be lifted.

Then, the weight of the load p 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 1.
3 and is converted into a digital signal and input to the computer 14.

On the other hand, the signal from the operating lever 7 is amplified by the lever signal amplifier 12', and then the third A/D
The signal is digitally converted by the conversion group 13' and inputted to the computer 14 as a (+) signal.

Therefore, both signals are added in the computer 14, and the added digital signal is again converted into a voltage as an analog signal by the second D/A converter 15, and sent to the input adjustment clutch 5a of the torque converter 5. 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 after rising to a certain height, the signal from the manual operating device becomes zero, so the output of the computer 14 becomes equal to the input from the load detector 11. Since only the output signal is sent to the torque converter 5 side, the torque converter 5 is controlled to a stall point corresponding to the magnitude of the load, and the load p is suspended at a constant height without a brake. Then brake 3
Apply clutch b and release clutch 3a. In that state, Aircraft 1
After turning to a desired angle, the clutch 3a is engaged and the brake 3b is released to lower the cargo, and the cargo p is automatically suspended in the air by the above-mentioned action. Next time, if the lever 7 is moved to the lower side (forward), a signal of a (-) amount corresponding to the amount of movement will be transmitted, this will be input to the computer 14, and the data signal from the load detector 11 will decrease. and output. The torque converter 5 is controlled to the lowering state by the output signal, and the load p is lowered at a speed commensurate with the amount of movement of the manual operation lever 7.

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.

Further, when the brake 3b is applied and the clutch 3a is released with the load p suspended in the air, the signal from the load detector 11 continues to be sent to the input adjustment clutch 5a of the torque converter, so the torque converter 5, The power transmission device 6 will spin idly, so if it is necessary to avoid this,
A switch interlocked with the engagement and disengagement of the clutch 3a for engaging and disengaging the gear may be provided at the connection between the load detector 11 and the amplifier 12. That is, when the clutch 3a is released, the amount of signal sent from the load detector 11 to the torque converter input adjustment clutch 5a becomes zero, the same as when no cargo is suspended, so the output rotation speed of the torque converter becomes zero. Become.

As described above, according to the present invention, instead of the driver searching for the stall point of the torque converter by groping as in the past, the driver can move the operating lever to a certain position called the neutral position. , the input of the torque converter is controlled to the stall point torque according to the weight of the suspended load, making it easier to lift the load.
The suspension can be reliably stopped, improving operability and allowing quick transition to the next operation, increasing work efficiency.Furthermore, since suspension work is not done as a guideline, the load can be increased. You can work safely without slipping or falling.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional crane, FIG. 2 is a plan view thereof, and FIG. 3 is a side view of an embodiment of the present invention.
FIG. 4 is a plan view thereof, and FIG. 5 is a block diagram of the control system. In the diagram, 1... fuselage, 1a... driver's cabin, 2... jib, 3
...Hoisting drum, 3a...Clutch, 3b...
Brake, 4... Prime mover, 5... Torque converter, 5a... Input adjustment clutch, 6... Power transmission device, 7... Operating lever, 8a, 8b... Wire, 11... Load detector, 12, 12 '...Amplifier, 13, 13'...A/D converter, 14...Computer, 15...D/A converter.

Claims (1)

[Claims] 1 A torque converter is interposed in the power transmission device connecting the prime mover and the hoisting drum, and an operating lever is provided to control the hoisting operation, and the operating lever controls the input of the torque converter to raise and lower the load and suspend the hoist. The hoisting device is equipped with a load detector that measures the weight of the load in relation to the lifting wire and transmits it as an electrical signal, and the operating lever is configured to detect changes in the amount of operation by adjusting the hoisting and lowering directions by an amount opposite to positive or negative. The electrical signal transmitted by the load detector and the electrical signal transmitted by the operating lever are both converted into digital quantities. It is equipped with a computer that converts, receives, and adds both electric signals, converts the electric signal of the addition amount sent from the computer into an analog amount, controls the input of the torque converter, and winds and winds with the positive and negative positions of the operating lever. A control device for a torque converter in a crane, etc., characterized in that when the operating lever is lowered and the operating lever is at the neutral position, the torque converter stalls and the load is suspended in the air.