JPH0453796B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a control device for a torque converter used in a power transmission device in a hoisting device such as a jib crane or a mobile crane. The purpose is to control the torque converter efficiently and safely with easy operation.

[Prior Art] A recent crane hoisting device using an engine or a motor as the prime mover a is shown in FIGS. A torque converter t is interposed to convert the input torque from the prime mover a according to the weight of the suspended load p and transmit it to the hoisting drum d.

In the process of normal hoisting work using such a hoisting device with a built-in torque converter, the load p lifted to a certain height is lifted higher or lowered, or the aircraft F is lifted with the load p lifted to a certain height. When the load p is already temporarily suspended, such as when the load p is lowered after turning, the work to change its position occurs.

Conventionally, this is done as follows.
That is, since the output torque of the torque converter is controlled by the control lever 1, in order to stop the load p after it has been raised to a certain height, the control lever 1 is returned to the position where the load p stops rising.

The operating angle of this operating lever 1 is the stall point of the torque converter t (the output torque of the torque converter becomes equal to the load torque required for lifting the load, and the output shaft of the torque converter rotates regardless of the rotational speed of the prime mover). (the point where the number becomes zero), the load p becomes suspended in the air and stops. At this point, the mechanical brake b is applied once to end the winding operation.

Next, in order to raise or lower the suspended load, first align the operating lever 1 to the stall point of the load, release the mechanical brake and suspend the load p, and then
The load p is adjusted by adjusting the output torque of the torque converter.
Raise and lower.

To align the operating lever 1 with the stall point of the load, the driver must move the operating lever 1.
is manually operated, and the amount of operation is transmitted to the torque converter t by oil pressure, air pressure, voltage, etc., and the input torque of the prime mover a is controlled by adjusting the slip rate of the input adjustment clutch s. The operator ultimately determines the operating position of the operating lever 1 for controlling the adjusting clutch s.

[Problems to be solved by the invention] This stall point changes depending on the weight of the load, and even torque converters of the same type have slightly different characteristics. It is difficult to specify in advance.

Since the positioning of the control lever is done as a guide, if the control lever 1 is set below the stall point, when brake b is released, the load p will start to fall, and conversely, if it is set above the stall point, the load p will start to fall. In this case, the load p rises immediately when the brake b is released, and it requires skill to remove the brake, that is, to suspend the load, and the stall point corresponding to the size of the load is spread over the entire operating range of the control lever. Therefore, it takes some time to operate, is complicated when there are many types of loads, reduces work efficiency, and is not good in terms of safety.

Since jib cranes and the like equipped with torque converters have many advantages, various proposals have been made to overcome these operational difficulties, but the present invention has also been devised to overcome the above-mentioned disadvantages. The present invention provides a control device that is easy to operate, efficient, and ensures safety.

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention provides a torque converter in the power transmission device that connects the prime mover and the hoisting means, and converts the torque through the speed acceleration/deceleration amplifier. In a hoisting device that is equipped with an operating means for controlling the hoisting operation by operating the operating circuit of the converter, and that controls the torque converter to raise and lower the load and suspend the load, the output shaft of the torque converter has a shaft that stops rotating. A speed detector is provided which detects the change in the manipulated variable and transmits a detection signal thereof, and receives a signal indicating a change in the manipulated variable from the operating means at the same time as the speed acceleration/decreasing amplifier, and from the speed detector. A computer is provided to receive the detection signal of the torque converter output shaft, and the computer captures and stores only the signal at the time when the torque converter output shaft is stopped, which is specified by the signal from the speed detector, from among the signals received from the operating means. Based on the stored signal, a signal for setting the base voltage of the speed increasing/decreasing amplifier is sent to the speed increasing/decreasing amplifier.

The present invention will be described in more detail with reference to the block diagram of FIG. 5. A torque converter is interposed in the power transmission device that connects the prime mover and the hoisting winch, and the torque converter is controlled to raise and lower the load and to stop the load in mid-air. The operating hoisting device has a hydraulic (or pneumatic) operating circuit that controls the torque converter, and the circuit usually includes a control valve (e.g. electromagnetic proportional control valve) that is remotely operated by electricity (or working fluid). pressure reducing valve) is incorporated.

The output shaft of the torque converter is equipped with a speed detector (for example, an encoder) that detects when the rotation of the shaft has stopped and sends this information to the computer.

On the other hand, in the operator's cab of the crane, there is an operating lever that controls the hoisting operation, and this lever is equipped with one potentiometer each for hoisting and lowering.
These allow the lever to define the voltage of the electrical signal it emits by varying the lever angle.

The speed adjustment amplifier outputs an operating current commensurate with the signal received from the operating lever to operate the electromagnetic proportional pressure reducing valve of the torque converter operating circuit.

The operating lever also sends an equivalent signal to the speed increasing/decreasing amplifier and at the same time sends an equivalent signal to the computer via the A/D converter.

Of the signals that are sent to it, the computer captures and stores only those signals at the time when the output shaft of the torque converter stops.

Further, the computer sends a signal to the amplifier via the D/A converter to set the base voltage of the speed acceleration/decreasing amplifier based on the stored signal.

The speed adjustment amplifier defines the operating current to be output according to the operating angle of the operating lever, based on the set base voltage. The output operating current remains constant until the voltage of the signal received from the operating lever reaches the base voltage, and the output current increases (decreases in the case of lowering) for a signal with a voltage higher than that.

In this way, the speed of the torque converter is controlled by operating the electromagnetic proportional pressure reducing valve of the operating hydraulic circuit of the torque converter using the operating current output from the speed adjustment amplifier.

[Effect] The effects of the present invention are as follows.

When the driver operates the operating means, a signal indicating a change in the operating amount is sent to the torque converter operating circuit via the speed acceleration/reduction amplifier, the torque converter is controlled, and the power of the prime mover is hoisted by the power transmission device. The information is transmitted to the means, and the operations of raising and lowering the load and stopping the suspension in the air are performed.

A signal indicating a change in the operating amount based on the operation of the operating means is sent to the operating circuit of the torque converter and at the same time to the computer. On the other hand, the speed detector installed on the output shaft of the torque converter detects that the rotation of the output shaft has stopped.
The detection signal is also sent to the computer.

Of the signals received from the operating means, the computer captures and stores only the signal at the time when the torque converter output shaft is stopped, which is specified by the signal from the speed detector, and controls the speed acceleration/deceleration amplifier based on the stored signal. A signal for setting the base voltage of the operating means is sent to the amplifier, and the amplifier defines the operating current to be output according to the operating amount of the operating means, based on the set base voltage.

Furthermore, the relationship between each member will be explained in more detail.

(1) Torque converter operating lever Sends an electrical signal determined by the operating angle of the lever to the speed acceleration/reduction amplifier. The operating lever directly adjusts the voltage of the electrical signal it transmits by means of the attached winding and lowering potentiometers in accordance with the operating angle of the operating lever. This characteristic is shown in FIG.

On the other hand, the control lever sends a signal to the amplifier and at the same time sends the same signal to the computer via the A/D converter.

(2) Torque converter operating circuit A torque converter is controlled by adjusting its input adjusting clutch to adjust the input torque from the prime mover.The input adjusting clutch has an operating hydraulic (or pneumatic) circuit, and ultimately It will control the hydraulic pressure (or pneumatic pressure) in that circuit.
For this purpose, a control valve (electromagnetic proportional pressure reducing valve) is provided in the circuit, and an operating current is sent from a speed acceleration/reduction amplifier to operate the control valve.

(3) Torque converter speed acceleration amplifier Amplifies the signal sent from the operating lever and outputs operating current for the electromagnetic proportional pressure reducing valve provided in the operating hydraulic circuit of the torque converter. The operating current changes depending on the operating angle of the operating lever.
How it is output from the amplifier is determined by the setting of its base voltage. 6th
The figure shows the relationship between base voltage and lever angle.

To explain according to Fig. 6, when the base voltage is the lowest value, the neutral point of the lever (lever angle =
0), the operating current is output according to the change in angle. When the base voltage is the value at point a, the value of the output current is constant until the point where the voltage of the initial potentiometer is equal to that of the lever, that is, the lever angle is at point b. This means that if the base voltage is a value corresponding to the stall point for the suspended load at that time, in order to hoist that load, hoisting will not begin until the operating angle of the lever has passed point b, and will move toward point a. As it progresses, the winding speed increases. Next, when the lever is returned to below point b, it becomes a stall point and the load becomes suspended in the air and stops.

If the base voltage is constant, the control of the torque converter relative to the operating angle of the lever will always be the same, and equivalent control will be possible with the same lever operation.

The base voltage is set by a signal sent from the computer.

(4) Speed detector of torque converter output shaft A speed detector is provided at the output of the torque converter, and it detects the stall point for each load, that is, the signal (for example, a pulse signal) when the rotation speed of the output shaft reaches zero. send and send it to the computer.

(5) Computer The same signal that is sent from the operating lever to the amplifier is sent to the computer via the A/D converter.

On the other hand, a signal to stop the rotation of the output shaft sent from the speed detector of the torque converter output shaft is received, and only the control lever signal at this time is captured and stored.

This stored signal allows the computer to send a signal to the D/A to set the base voltage of the amplifier.
It is sent to an amplifier via a converter. Therefore, the base voltage of the amplifier can be kept constant as long as work continues with the same weight of load.

Since each element operates as described above, in this device, the electromagnetic proportional pressure reducing valve of the operating hydraulic circuit of the torque converter is remotely controlled by the operating current output from the speed acceleration/decreasing amplifier by operating the operating lever. In order to lift a load, the lever operation angle exceeds the point specified by the base voltage, and if the angle is further increased, the hoisting speed of the load increases. Also, if the load is returned to below the specified point, the load stops increasing and becomes suspended in the air.

To lower the winding, simply move the lever in the opposite direction from the neutral point, and the effect is the same as for winding up.

Crane work generally involves hoisting a load, temporarily stopping the lift, and suspending the load in the air.

In this operation, the movement of the operating lever always passes through the position of the stall point of the load.

The present invention reliably captures the operating lever signal at this time, stores it, and sets the base voltage of the speed acceleration/reduction amplifier. Once the base voltage is set, the position of the stall point of the operating lever can be specified and the torque converter can be easily controlled.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 3 and 4.

The fuselage 1 is rotatably arranged on a base, and as usual, a jib 2 of a required length is pivotally supported at the front end of the fuselage 1 by a raised rope 14b, and inside the fuselage 1 are: Clutch 3a for transmission attachment/detachment on one side
, a hoisting drum 3 with a brake 3b on the other side
A prime mover 4 such as an engine or a motor, and a torque converter 5 with a multi-plate input adjustment clutch 5a are arranged behind it, and this torque converter 5 has a power transmission device 6 including a belt or chain mechanism and gears. It is connected to the winding drum 3 via the winding drum 3.

A control lever for operating the drum and a control lever 7 for controlling the torque converter are provided in the operator's cab 1a at the front of the machine, and a hoisting rope 14a extending from the hoisting drum 3 passes through multiple sheaves at the jib head and is directed downward. A hook block 15 is suspended in the middle, and its tip is connected to the jib head.

Incidentally, in the present invention, a speed detector 10 is provided on the output shaft of the torque converter 5, and a computer 11 and an operating lever 7, which are electrically connected to the speed detector 10, are installed in the operator's cab 1a of the aircraft 1.
A/D converter 1 converts the electrical signal of the operating lever 7 into a digital quantity and sends it to the computer 11.
2. D/A converters 13 are sequentially provided to convert a digital signal sent from the computer 11 to the speed acceleration/subtraction amplifier for setting the base voltage.

On the other hand, the torque converter 5 is provided with an operating hydraulic circuit 5b that controls the input adjustment clutch 5a.
It has an electromagnetic proportional pressure reducing valve 8, which is remotely operated by an operating current output from an electrically connected speed amplifier 9.

In this manner, the hydraulic pressure of the operating hydraulic circuit 5b of the input adjusting clutch 5a is adjusted, and the slip rate of the clutch 5a is adjusted to control the torque input from the prime mover 4 to the torque converter 5, thereby performing so-called speed control of the torque converter.

With the above configuration, when working with the crane, the clutch 3a of the hoisting drum 3 is disengaged, the brake 3b is released, and the drum 3 is
is released, the lifting wire 14a is let out, the hook block 15 is lowered, the brake 3b is applied, the drum 3 is temporarily stopped, and the load p is applied to the hook block 15.
When the clutch 3a is engaged, the brake 3b is released, and the control lever 7 is operated from the neutral position to the upward side, the load p is hoisted up.

When the load p reaches a predetermined height, the operating lever 7 is returned to the neutral position to temporarily stop the operation.

While the lever is being returned, the output shaft of the torque converter 5 reaches zero rotational speed. The operating signal of the operating lever 7 at this time is captured and stored in the computer 11, and the base voltage of the amplifier 9 is immediately set, and the position of the stall point of the load p is specified in the operating angle section of the operating lever 7. . That is, from the neutral position of the lever 7 to that point, the output shaft of the torque converter 5 is stopped.

Therefore, from now on, when the load p has risen to a predetermined height, if the operating lever 7 is returned to below the lever position of the stall point, the load p will be suspended at a certain height without the brake, and then the brake will be applied. Engage clutch 3b and release clutch 3a.

After turning the aircraft 1 at a desired angle in this state,
To lower the load p, engage the clutch 3a and release the brake 3b, and the load p will be suspended in the air by the action already described.

Next, when the operating lever 7 is operated to the lower side and the operating angle passes the stall point position, a signal corresponding to the angle is transmitted, this is amplified by the amplifier 9, and the operating current is transferred to the torque converter. It is sent to the electromagnetic proportional pressure reducing valve 8 in the operating hydraulic circuit 5b of the input adjustment clutch 5a, and works to lower the hydraulic pressure, increasing the slip rate of the input adjustment clutch 5a.
The torque converter 5 is controlled to be lowered,
The load p falls at a speed commensurate with the operating angle of the operating lever 7.

To raise it again, operate the drum clutch and drum brake in the same way as above, then press the operating lever 7.
When it is operated to the upward side and it passes the stall point, the load p starts to rise, and if the operating angle is further increased, it will rise at a commensurate speed.

In the above example, the characteristics of the operating lever 7 were described in the case of the initial potentiometer (solid line) shown in FIG. You can also do it. In this case, the neutral position of the lever 7 becomes the stall point, and the speed can be adjusted over the entire operating angle of the lever, making speed control easy.

Furthermore, in the above explanation, the number of potentiometers that are the components of the operating lever 7 was described as two, but one
Individuals can also have similar functions.

[Effects of the Invention] As described above, the present invention has been achieved in a hoisting device such as a crane equipped with a torque converter. However, the position of the operating lever of the stall point of the torque converter according to the weight of the suspended load is automatically identified each time, making it possible to suspend the suspended load easily and reliably. This improves operability, allows quick transition to the next operation, increases work efficiency, and allows work to be carried out with a high degree of safety.

[Brief explanation of the drawing]

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, FIG. 5 is a block diagram connecting the components of the device, and FIG. 6 is a characteristic diagram of the operating lever. 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, 5b...
Operating hydraulic circuit, 6... Power transmission device, 7... Operating lever, 8... Electromagnetic proportional pressure reducing valve, 9... Speed acceleration/decreasing amplifier, 10... Speed detector, 11... Computer, 12... A/ D converter, 13...D/A
Converter, 14a... Hoisting rope, 14b... Hoisting rope, 15... Hook block.

Claims (1)

[Claims] 1. A torque converter is interposed in the power transmission device that connects the prime mover and the hoisting means, and an operating means is provided for controlling the hoisting operation by operating the operating circuit of the torque converter via a speed acceleration/decreasing amplifier, and controlling the torque converter to control the load. In the hoisting device that performs the operations of raising and lowering and stopping the suspension in the air, the output shaft of the torque converter is provided with a speed detector that detects when the rotation of the shaft has stopped and transmits a detection signal, and from the operating means, A computer is provided which receives a signal indicating a change in the manipulated variable at the same time as the speed acceleration/decreasing amplifier and also receives a detection signal from the speed detector. Captures and stores only the signal at the time when the torque converter output shaft stops, which is specified by the signal from the speed detector, and sends a signal to the speed acceleration/reduction amplifier to set its base voltage based on the stored signal. A control device for a torque converter in a hoisting device, characterized in that it is configured as follows.