JPS61235396A - Bucket crane device - 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] [Field of Industrial Application] The present invention provides a bucket crane that is equipped with a bucket support motor and a bucket opening/closing motor, and these motors are used to move the bucket up and down, and to open and close it. The present invention relates to a device, and more particularly, to a bucket crane device in which the output torques of the two electric motors are matched during closed-up or closed-down operation in which the bucket moves up or down while holding cargo or the like.

[Conventional technology]

FIG. 2 shows a bucket crane device of this type according to the prior art.

In the figure, 1 is a supporting electric motor that supports a bucket, which will be described later.
2 shows an opening/closing electric motor that opens and closes the bucket. in general,
The support motor 1 and the opening/closing motor 2 are operated with the same capacity. The support electric motor 1 supports the bucket 7 via the support drum 3 and the support rope 4. Further, the opening/closing electric motor 2 is configured to open/close the bucket 7 by an opening/closing lobe 6 via an opening/closing drum 5.

Incidentally, the operation of the equal capacity bucket crane is generally performed by grasping the object to be transported (sinking and grasping control), driving the opening/closing electric motor 2, hoisting the opening/closing lobe 6, and closing the bucket 7. After the closing is completed, both the supporting and opening/closing electric motors 1.2 are driven to wind up the bucket 7 while keeping the bucket closed. Next, after the bucket 7 is transported to a predetermined position by a moving drive device such as traversing or traveling, both the supporting and opening/closing electric motors 1 and 2 are driven to lower the bucket 7 while keeping the bucket closed.

After lowering it to the predetermined position, the opening/closing motor 2
is driven to lower the opening/closing row 16, open the bucket 7, and release the held object. After the object to be transported is released, it is returned to a predetermined point by the traversing or traveling drive device, and both the supporting and opening/closing electric motors 1.2 are driven to lower the supporting lobe 4 and the opening/closing row 16. Cargo handling operations using the bucket crane device are performed by repeating such operations.

The operation is shown in FIG.

This time, in this series of operations, we will use the closing method (A) in Figure 3 above.
We will now discuss the operation of the closure (B).

The closed up (A) and closed (B) operations are performed with the bucket 7 completely closed, and the closed up (A) operation is performed when both the supporting and opening/closing electric motors 1 and 2 are operated in the hoisting direction. Drive to,
In addition, for closing (B) operation, both electric motors for support and opening/closing 1.2
All you have to do is drive it in the lowering direction.

At this time, since the load is applied equally to both the support lobe 4 and the opening/closing lobe 6, both electric motors 1.2 generate equal torque evenly during the closing (A) and closing (B) operations. There is a need.

For this reason, in conventional thyristor secondary voltage control,
The torque detection method shown in FIG. 4 and the main circuit switching method shown in FIG. 5 were used.

Next, the torque detection method shown in FIG. 4 will be explained.

In the figure, 11 and 12 are finger speed generators directly connected to the respective electric motors 1 and 2, and 13 is a controller serving as an operation setting means for giving speed commands to the electric motors 1 and 2. The voltage value is compared with a speed feedback signal proportional to the speed of the motor 1.2 detected by the finger speed generator 11.12, and the comparison difference is amplified by the respective amplifier 14.15. It has become so. Therefore, 16.17 is the support motor 1
These thyristor stacks 16 and 17 each supply a positive-sequence voltage and a negative-sequence voltage to the support side thyristor device 18. Also, 19.2
Reference numeral 0 denotes a thyristor stack that supplies a positive-sequence voltage and a negative-sequence voltage to the switching motor 2, respectively, and these thyristor stacks 19 and 20 constitute an opening-closing side thyristor device 21. 22.23 and 24.25 are gate signal circuits for support and opening/closing, and these gate signal circuits 22, 23 and 24.25 are based on the comparative difference outputs output from each of the amplifiers 14.15. , the firing phase of each thyristor stack 16, 17 and 19, 20, thereby controlling the speed of each electric motor 1.2.

In addition, 26.27 is a current transformer for torque detection, which feeds back the generated torque of each electric motor 1, 2 by current detection, inputs the generated torque to the current conversion circuit 28.29, and converts the generated torque to each current conversion circuit. In this method, the inputs of 28 and 29 are compared, and the output of the amplifier 14 and 15 is limited by the clamp circuits 30 and 31 based on the comparison difference, so that the torques generated by both electric motors 1 and 2 are generated equally. .

That is, in the above configuration, a speed command is given from the controller 13, and the motor speed is determined by the finger speed generator 11.1.
Based on the speed feedback signal detected by 2, each of the support side and opening/closing side configures a closed loop automatic control circuit.
In order to correct the unbalance of generated torque due to speed fluctuations, etc., the torque correction method using current detection is used.

However, when such a compensation means is used, the structure thereof is complicated, lacks stability, and takes time to adjust. To solve this problem, there is a main circuit switching method as shown in FIG.

Identical equal signs in FIGS. 4 and 5 indicate identical parts.

The basic operation is the same as the torque detection method shown in Fig. 4, but if the characteristics of the induction motors, that is, the secondary side resistance values are equal, and the primary voltages given to each motor 1.2 are the same,
This utilizes the characteristic of generating equal torques. The main circuit is equipped with 32°33.34 main contactors, and in the case of closing (A) and closing (B), these main contactors 32, 3
The purpose is to generate equal torques by turning 3.34 ON and OFF. That is, in the case of closure (A) and closure (B), the main contactors 32 and 33 are ONL,
The main contactor 34 is at 0FFL, so that both electric motors 1.2 are supplied with power via the support side thyristor stack 16, 17, so that the primary voltages of both electric motors 1, 2 are equal and the generated torque is also become equal.

In this case, automatic control is basically the same as in the case of FIG. 4, and a current transformer for torque detection is not required.

This simplifies the circuit configuration and equalizes the generated torque, but the supporting side thyristor stacks 16 and 17
In order to bear the burden of two 1.2° electric motors for both support and opening/closing, twice the capacity of the opening/closing side thyristor stack 19.20 is required.

Also, main contactor 32.33.34 for main circuit switching
This increases the cost and increases the number of electromagnetic control panels, resulting in poor economic efficiency.

[Problem that the invention seeks to solve]

In this way, in a conventional crane with equal capacity, in order to generate equal torque for both the supporting and opening/closing motors 1.2, the torque detection method shown in Fig. 4 and the main circuit switching method shown in Fig. 5 are used. However, the former has a complicated circuit configuration and lacks stability, while the latter has support side thyristor stacks 16 and 17 twice the rated capacity, and also has a main contactor 32 for switching the main circuit, 33 and 34 were added, which led to an increase in the number of electromagnetic control panels, resulting in an increase in price and poor economic efficiency, which caused many problems. Accordingly, an object of the present invention is to provide a bucket crane device that is simple in construction, capable of reliable torque balance control, and in which the supporting side and opening/closing side thyristor devices can be configured with rated capacities.

[Means for solving problems]

In the present invention, there is provided a closing and closing operation setting means for performing a closing operation in which the bucket moves up and down while the bucket is closed, or a closing operation, and a support side thyristor device and an opening/closing side when the bucket is closed or closed down. and control means for setting the thyristor devices to the same ignition.

[Effect]

In the present invention, when the bucket is closed or closed, the control means sets the supporting side thyristor device and the opening/closing side thyristor device to the same ignition, so that the output torque of both the electric motors for supporting the bucket and for opening/closing the bucket is controlled. be the same.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG. Note that the same components as those in the prior art are given the same reference numerals, and the description thereof will be omitted.

However, as is clear from comparing FIG. 1 with FIGS. 4 and 5, the feature of the present invention is that a gate signal switching circuit 35 is newly added, and the supporting side width is increased. The comparison difference output of the amplifier 14 and the amplifier 15 is sent to the gate signal circuit 24.1 through the gate signal switching circuit 35.
25. Further, the gate signal switching circuit 35 has a closing switch for causing the gate signal switching circuit 35 to perform a closing operation or a closing down operation.

The closure setting means 36 is connected and the support side amplifier 14.11
The comparison difference output of the first open/close side amplifier 15 is selected via the gate signal switching circuit 35.

That is, when the bucket 7 is closed or closed down, the gate signal switching circuit 35 transmits the comparison difference output signal of the support side amplifier 14 to the opening/closing side gate signal circuit 24.25 by the closing/closer setting means 36. The purpose is to connect the same comparison difference output signal to the switching and supporting side gate signal circuits 22 and 23. For this reason, the supporting side thyristor stack 16.17
The opening and closing side thyristor stacks 24 and 25 are controlled to have the same firing phase.

The gate signal switching circuit 35 constitutes a control means for setting the support side thyristor device 18 and the opening/closing side thyristor device 21 to the same ignition.

Therefore, during closing and closing down operation, based on the comparison value of the support side closed loop automatic control circuit based on the speed command signal from the controller 13 and the speed feedback signal of the support side finger speed generator 11,
The comparative difference output signal of the support side amplifier 14 is transmitted from the support side gate signal circuit 22.23 and the opening/closing side gate signal circuit 24.25 to the same point on the supporting side thyristor stack 22.23 and the opening/closing side thyristor stack 24.25, respectively. Arc phase control is performed to equalize the primary voltages applied to both the support and opening/closing motors 1.2.

Therefore, due to the characteristics of induction motors, that is, the characteristics that generate equal torques when the secondary resistance values of both motors 1 and 2 are equal, that is, they have the same capacity, and the applied primary voltages are equal, the power supply fluctuation No torque imbalance occurs between the two electric motors 1.2 even when the electric motors 1.2 are used, reliable torque balance control is possible, and both the supporting and opening/closing electric motors 1.2 can generate equal torques.

In the above embodiment, the thyristor stacks 22, 23 and 2
Although the case of reversible connection of 4.25 has been described, this may be made irreversible and the forward and reverse phases may be switched using a reversible contactor (not shown). Also, it is of course possible to hook the hook instead of the bucket 7.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a closing/closing operation setting means for performing a closing operation in which the bucket moves upward or downward while the bucket is closed, or a closing/closing operation, and a closing/closing operation setting means for causing the bucket to move upward or downward while the bucket is closed. Since a control means for setting the support side thyristor device and the opening/closing side thyristor device to the same ignition is provided, reliable torque balance control is possible with a simple configuration, and support and opening/closing control without mechanical connection is provided. Since the plurality of electric motors generate the same torque, it is possible to obtain a control device for a bucket crane of equal capacity with good stability.

In addition, since the entire device is simpler than conventional products, it can be made cheaper.

[Brief explanation of the drawing]

11th! 1 is a block diagram showing an embodiment of a bucket crane device according to the present invention, FIG. 2 is a schematic configuration diagram of an equal capacity bucket crane, FIG. 3 is an operation diagram of an equal capacity bucket crane, and FIG. 4 is a diagram of a conventional thyristor. A block diagram showing a torque detection method using next voltage control. FIG. 5 is a block diagram showing a main circuit switching method using conventional thyristor next voltage control. 1... Support electric motor, 2... Opening/closing electric motor, 13... Operation setting means (controller)
, 18...Support side thyristor device, 21...
... Opening/closing side thyristor device, 35... Control means (gate signal switching circuit).

Claims (1)

[Claims] a supporting electric motor that raises and lowers the bucket; an opening/closing electric motor having the same capacity as the supporting electric motor and opening and closing the bucket; a supporting side thyristor device that controls ignition of the primary voltage of the supporting electric motor; A closed-up thyristor device that controls firing of the primary voltage, and an operation setting means that sets firing angles of the support-side thyristor device and the opening-closing thyristor device, and that raises and lowers the bucket while it is closed; In a bucket crane device that performs closed-down operation and open-close operation that opens and closes the bucket, closed-up and closed-down operations are performed to perform closed-up and closed-down operations in which the bucket moves up and down while the bucket is closed. By providing a setting means and a control means for setting the supporting side thyristor device and the opening/closing side thyristor device to the same ignition when the bucket is in the closed-up or closed-down operation, , a bucket crane device characterized in that the output torques of the two electric motors are the same.