JPS602596A - Cargo-handling conveyor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cargo handling and transporting machine that raises and lowers cargo by increasing and decreasing the driving force of a modele and adjusting a cargo lifting blade of a cargo lifting mechanism.

A conventional device of this type is the one shown in Figure 1.

In the figure, (1) is a speed setting circuit consisting of, for example, a potentiometer, which has an operating lever that self-returns to the stop command position due to the elasticity of a spring, and outputs a voltage depending on the operating angle and direction of this operating lever. shall be done;
When it is at the stop instruction position, a zero voltage is output, when it is turned to the upward direction, a positive voltage is output, and when it is turned to the downward direction, a negative voltage is output as the speed setting signal. (2) is the addition point where the speed setting signal from this speed setting circuit (1) is compared with the speed feedback signal from the speed detection circuit (7), which will be described later, and (3) is the comparison point at addition point (2). a speed-torque conversion circuit (hereinafter referred to as an S-T conversion circuit) that converts the deviation signal generated into a torque signal according to its magnitude; (4)
) is a drive circuit that drives the wl motor (5), which will be described later, with the torque corresponding to the torque signal from this ST converter circuit (3), and (5) is an output that corresponds to the output from this drive circuit (4). The electric motor is composed of a torque motor that generates torque, and generates torque only in the direction in which the load (8) is lifted by the load lifting mechanism (6). (7) is the above electric motor (5)
This is a speed detection circuit consisting of a speed generator, etc. that detects the rotation speed of the load (8).When the rotation is stopped, the voltage is zero, when the load (8) rotates in the upward direction, the voltage is negative, and when the load (8) rotates in the downward direction, the voltage is positive. is output as a speed feedback signal according to the rotational speed.

In the device configured as described above, when the load (8) is suspended from the load lifting mechanism (6) and suspended in the air, the operator releases the control lever and the control lever moves to the stop instruction position. If there is, the speed setting signal from the speed setting circuit (1) is zero, and if the cargo (8) is stopped, the speed feedback signal from the speed detection circuit (7) is also zero, so the deviation signal is also zero. zero, and the S-T conversion circuit (3
) is zero. Therefore, the drive circuit (4) also does not drive the electric motor (5), and as a result, the load lifting mechanism (6) does not generate a lifting blade, so the load (8) begins to descend. Then, a positive voltage speed feedback signal is output from the speed detection circuit (7), and the summing point (2
) is input to the s-"r conversion circuit (3) as a comparison signal.The S-T conversion circuit (3) outputs a torque signal, and the drive circuit (4) drives the electric J"I" shaft (5). Since the load lifting mechanism (6) is driven, the load lifting mechanism (6) generates a lifting blade and lifts the load (8).
) will impede the descent.

By repeating this process, the load (8) continues to descend at a constant speed. Therefore, if the amplification degree of both the S-T converter circuit (3) and the drive circuit (4) is made sufficiently large, the absolute value of the speed feedback signal will be almost equal to the speed setting signal, so the speed The feed bank signal is almost zero, and the descending speed of the load (8) is extremely slow.

Here, when the load (8) is suspended in the air and is descending at a very slow speed without being held even though the control lever is in the stop instruction position, when the control lever is moved to the upward direction, the speed can be set. A speed setting signal of positive voltage is output from the circuit (1), but since the speed feed bank signal is almost zero, the deviation signal becomes the positive voltage of the speed setting signal itself. Therefore, a large torque signal train corresponding to the magnitude of the speed setting signal is output from the ST conversion circuit (3) during compression, and the N, UJ+ machine (5) is driven by the large output from the drive circuit (4). The load (8) is suddenly driven to increase the torque in the lifting direction of the load (8), and the load (8) is lifted by the load lifting mechanism (6).
) is raised. Then, a speed feedback signal of negative voltage is output from the speed detection circuit (7), which acts to prevent the load (8) from rising, and at this point, the absolute values of the speed setting signal and the speed feedback signal become almost equal. The load (8) continues to rise at a constant speed.

Next, when the load (8) is suspended in the air and is descending at a very slow speed even though the control lever is in the stop instruction position, when the control lever is set to the descending instruction side (11), the speed is A speed setting signal with a negative voltage is output from the setting circuit (1), but since the speed feedback signal is almost zero, the deviation signal becomes the negative m pressure of the speed setting signal itself.ST conversion circuit ( The torque signal from 3) becomes zero, and the electric motor (5) lifts the load (8) without being driven by the drive circuit (4), losing torque in the direction of the load (8).
8) begins to descend.

Then, a positive voltage speed feedback signal is output from the speed detection circuit (7), which acts to prevent the cargo load 8) from lowering, and when the absolute values of the speed setting signal and the speed feedback signal become almost equal, the speed remains constant. Baggage at speed (8
) continues to decline.

As described above, the conventional device is configured with a speed feedback control system, so the change in the speed setting signal due to rotation of the operating lever is greatly amplified and power is supplied to the electric motor. Although the response is good, there is a drawback that the electric motor is driven suddenly and a large impact load is applied to the load lifting mechanism (6), and the vibration phenomenon that the torque fluctuates is likely to occur, and the operating lever stops. There were drawbacks such as the baggage (8) falling at a very slow speed without being held at the indicated position.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the signals from the position detecting means and the position setting means are compared, cumulatively decremented, and the value is converted into a torque by a position-torque conversion circuit. By converting it into a signal, it is possible to suppress the vibration caused by sudden torque fluctuations and the impact load on the load lifting mechanism, and also prevent the load from lowering when the operating lever is in the stop command position. Cargo handling It G
is intended to provide.

An embodiment of the present invention will be described below with reference to the block diagram shown in FIG. (2) 0 is a position setting circuit which outputs an upward movement claw instruction pulse or a downward movement amount instruction pulse for each unit operation angle displacement according to the operating direction of the handle or the like. (2
The movement distance instruction pulse and the position detection circuit (described later)
(e) is a summing point that compares the shift mfat feedback detection pulses and outputs a deviation signal pulse, and (a) is a position-torque conversion circuit (hereinafter referred to as P - (referred to as T-conversion circuit),
(4) is a drive circuit that drives an electric motor (5), which will be described later, with the torque corresponding to the torque signal from this P-T conversion circuit (E), and (A) detects the amount of rotational angular movement of the electric motor (5). The position detection circuit outputs an upward movement amount detection pulse or a downward movement shore detection pulse as a position feedback signal every 17-1 rotation angle displacement.

In the specific circuit diagram shown in Figure 3, (801) is a rotary encoder for indication, and a handle (802) is connected to the input shaft. An instruction two-phase signal (808) consisting of two different rectangular waves is output.

(804) is an instruction rotation direction discrimination circuit which receives the instruction two-phase signal (808) and outputs a pulse for each unit operation angle displacement of the handle (802). An instruction pulse (805) is output as a position setting signal, and when the handle (802) is rotated in the opposite direction, a downward movement amount instruction instruction pulse (806) is output as a position setting signal. (
807) is the logical sum of the upward movement amount instruction pulse (805)', the downward movement amount detection pulse (818) described later, and the above downward movement amount instruction pulse (806) and the upward movement amount detection pulse (817) described later. The gate circuit (!310) which performs the above cumulative pulse (808) and outputs the cumulative pulse (809) accumulates upon receiving the cumulative pulse (808), and outputs the cumulative decreasing pulse (809) in response to the cumulative pulse (808). A digital counter outputs a binary digital signal. (811) is a digital-to-analog conversion circuit (hereinafter referred to as I/A conversion circuit) which receives the digital signal from the digital counter (110) and outputs a torque signal which is an analog voltage. Correspondingly, a control element (81
8) is a phase control circuit for controlling the firing angle; (814) is a detection rotary encoder connected to the electric motor (5); N'? When machine A (5) rotates, it outputs a detection two-phase signal (815) consisting of two rectangular waves with a 90-degree phase (816) to distinguish between forward and reverse rotation.
receives the detected two-phase signal (815) and operates the electric motor (5).
) is a rotational direction discrimination circuit for detection that outputs a pulse for each unit rotational angular displacement, and when the electric motor (5) is rotating in the direction in which the load (8) rises, an upward movement fiIlffi detection pulse (817) is output. and when rotating in the downward direction, a downward movement ItJffi detection pulse (818) is output as a position feedback signal.

In the item configured as above, the baggage (8)
is suspended from the load lifting mechanism (6) and is in a suspended state, the handle (802) must be rotated or the instruction rotation direction determination circuit (804) will determine the position setting 4.
The ascending movement claw instruction pulse (805), which is g, and the incidental movement amount (r゛1 indication pulse (806)) are not output.If the load (8) is stopped, the detection rotation direction discrimination circuit (816) ) also does not output the upward movement amount detection pulse (817) and the downward movement claw detection pulse (sig), which are position feed bank signals, so the gate circuit (80
7), the cumulative pulse (・308) and the cumulative decrease pulse (80
9) are not output. Digital counter (810
) is zero, the digital signal does not change and remains zero since neither the cumulative pulse (308) nor the cumulative reduction pulse (809) are input. Since the D/A conversion circuit (sit) receives a zero digital signal and gives a zero torque signal to the phase control circuit (812), the control element (818) is not fired at all and the electric motor (5) 8) Do not generate torque in the direction of lifting. Then, the load (8) starts to descend, and the detection rotation direction discrimination circuit ff1-a (816) outputs a downward j movement amount detection pulse (818), which is sent to the gate circuit (8).
07) to a digital counter (810) as an accumulated pulse (808). When the digital signal of the digital counter (810) increases as it is accumulated for each unit decrease amount, the conversion circuit (
The torque signal from 811) also increases, and in response to this, the phase control circuit (812) widens the firing angle of the control element (aia). As the firing angle widens,! The voltage applied to the 8 machine (5) gradually increases, and the torque in the direction of lifting the load (8) also increases.

As this torque increases, the force with which the load lifting mechanism (6) lifts the load (8) approaches the gravity of the load (8), and the descending speed slows down, causing the lifting force and the gravity of the load (8) to slow down. It stops when the torque becomes equal, and thereafter it is maintained at the stopped position by the torque.

As mentioned above, when the handle (802) is rotated in the forward direction while the load (8) is suspended in the air, the instruction rotation direction determination circuit (804) outputs an upward movement amount instruction pulse (805) as a position setting signal. ) is the handle (802)
A number proportional to the operating angle is output. This upward movement F
, the hand instruction pulse (805) passes through the gate circuit (807) and is sent to the digital counter (810) as the cumulative pulse (80).
8) It is inputted as oshi. Then, the digital signal increases by an amount proportional to the number of cumulative pulses (808) that have just been input, and the force to lift the load (8) increases.
begins to rise seven times around the gravity of When the load (lack;) rises, an upward shift fJ ffl detection pulse (817) is output as an i1°lff feedback signal, which passes through the gate recall (a07) and becomes a cumulative decrease pulse (809).
), the digital signal of the digital counter (810) starts to decrease, and the upper back movement 4 detection pulse (817 ) continues to decrease until it is fed banked, and then the said cargo ・(8
) will stop when the lifting force becomes equal to the gravity of the load (8), and thereafter it will be maintained at the stopped position by the torque.

As mentioned above, when the handle (802) is rotated in the reverse direction while the load (8) is suspended in the air, the rotation direction determination circuit (804) outputs a downward movement amount instruction pulse ( 806) Handle (802)
) is output in proportion to the operating angle.

This downward movement amount instruction pulse (806) is applied to the gate circuit (806).
07) and is input to the digital counter (810) as a cumulative decrement pulse (809). Then, the digital signal becomes smaller by an amount proportional to the number of cumulative reduction pulses (309) that have just been input, and the force for lifting the load (8) becomes lower than the gravity of the load (8), and the load starts to descend. (
8) descends, a descending moving star detection pulse (818) is output as a position feedback signal, which passes through the gate circuit (807) and becomes a cumulative pulse (808), so the digital signal of the digital counter (810') starts to increase and continues to increase until the position feedback of the downward movement amount detection pulses (818) is the same as the downward movement amount instruction pulses (806) generated by the reverse rotation operation of the handle (802) (7). The load (8) is stopped when the force for lifting the load (8) becomes equal to the gravity of the load (8), and is thereafter maintained at the stopped position by the torque.

4 and 5 show other embodiments of the present invention, and in the figures, H is a speed generator (819) for detecting the rotational speed of the electric motor (5), etc. The circuit outputs a zero voltage when the rotation is stopped, a negative voltage when the load (8) rotates in the upward direction, and a positive voltage when the load (8) rotates in the downward direction as a feedback signal depending on the rotation speed. be done.

(E) is a summing point that compares the torque signal from the P-T conversion circuit (A) with the speed feedback signal from the speed detection circuit (C) and outputs the deviation signal to the drive circuit (4). It is.

In the device configured in this way, the rotational speed of the electric motor (5) is output as a speed feedback signal from the speed detection circuit to the summing point (A), so that the P-T
The torque signal from the conversion circuit (e) is suppressed by the speed feedback signal. That is, when a torque signal is output from the P-T changeover circuit (2) based on the command value from the position setting circuit Q]), this torque signal causes the electric motor (5) to accelerate through the drive circuit. Although the speed tends to increase, the speed feedback signal suppresses the sudden increase in speed, and the electric motor (5) rotates while suppressing large fluctuations in speed.

As described above, the present invention includes a load lifting mechanism for lifting a load, a power source for driving the load lifting mechanism, a position setting means for instructing the movement ff1bffi of the load lifting mechanism,
position detection means for detecting the amount of movement of the load lifting mechanism;
The position at which the signals from this position detection means and the position setting means are compared, cumulatively decremented, and the value is converted into a torque signal.
Since it is provided with a torque conversion means and a drive circuit that generates a required torque in the power source in response to the torque signal, the torque signal reaches a predetermined value based on the cumulative decrease of the signal. This has the effect of suppressing the rise of the drive signal to the power source, suppressing the impact load on the load lifting mechanism, and preventing the occurrence of vibrations caused by sudden torque fluctuations.Also, the control lever is in the stop command position. In this case, a torque equal to the gravity of the load is maintained, which has the effect of preventing the load from descending.

In addition, when the configuration is such that the power source generates the required torque in response to the deviation signal l between the position-torque changing means and the speed detecting means, the P-T is determined by the speed feedback signal.
This has the effect of suppressing rapid changes in the conversion means, preventing sudden acceleration of the speed of the electric motor, and making it possible to smoothly raise and lower the load.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional device, Fig. 2 is a block diagram showing an actual commercial example of the present invention, Part 3 is a circuit diagram showing the specific configuration of Fig. 2, and Fig. 4 is a block diagram showing an example of the present invention. FIG. 5 is a block diagram showing an embodiment of the pond, and FIG. 5 is a circuit diagram showing a specific configuration of FIG. In the figure, (2) is the addition point, (4) is the drive circuit, (5) is the electric motor, (6) is the load lifting mechanism, (
8) Is it luggage? υ is the position setting circuit, (A) is the P-T conversion circuit, (A) is the position detection circuit, force is the speed B [detection circuit, 'JG 1. i is the addition point. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa

Claims (2)

[Claims] (1) A load lifting mechanism for lifting a load, a power source for driving the same, a position setting means for instructing the amount of movement of the load lifting mechanism, and a position setting means for instructing the amount of movement of the load lifting mechanism. a position detecting means for detecting, a position-torque converting means for comparing and cumulatively decrementing the signals from the position detecting means and the position setting means, and converting the value into a torque signal; A cargo handling/transporting machine comprising a drive circuit that generates the required torque from the above-mentioned power source. (2) A load lifting mechanism for lifting a load, a power source for driving the same, a position setting means for instructing the amount of movement of the load lifting mechanism, and a position setting means for instructing the amount of movement of the load lifting mechanism. a position detecting means for detecting, a position-torque converting means for comparing and accumulating signals from the position detecting means and the position setting means and converting the value into a torque signal, and moving the load lifting mechanism. A cargo handling and transporting machine comprising a speed detection means for detecting speed, and a drive circuit for generating a required torque in the power source in response to a deviation signal between the position-torque conversion circuit and the speed detection means.