JPWO2020101033A1 - Hoisting motor overload determination method and hoisting machine manufacturing method - Google Patents

Abstract

Provided is a method for determining an overload of a hoisting motor, which enables accurate overload determination and can continue to perform accurate overload determination even if the overload threshold value is changed.
A reference function that defines the current (i) by the quadratic equation of the input voltage (v) based on the A step that applies various loads to the reference hoisting motor and measures the relationship between the input voltage and the current. Step B for deriving a reference overload determination threshold curve as a reference threshold for overload determination, step C for determining whether to change the reference overload determination threshold curve, and a reference overload determination threshold curve. If is not changed, the overload of the target hoisting motor is determined based on the reference overload determination threshold curve, and if the reference overload determination threshold curve is changed, the section of the reference function is corrected. Includes a D step of determining the overload of the target hoisting motor based on the corrected overload determination threshold curve consisting of the equation.

Description

The present invention relates to a method for determining an overload of a hoisting motor and a method for manufacturing a hoisting machine.

The hoisting machine is equipped with an overload limiter (Over Load Limiter), which is a safety device for preventing accidents due to overload and damage to the motor (winding motor). The OLL includes a mechanical OLL that stops the hoisting when the clutch slips due to a predetermined overload, and an electronic OLL that detects the overload from the value of the motor current and electrically stops the hoisting. Some hoisting machines are equipped with both mechanical and electronic OLLs, so that in such hoisting machines, the electronic OLL usually operates first and the mechanical OLL complements (backs up) it. (The electronic OLL threshold is set between the rated load and the mechanical OLL set value).

The electronic OLL is required to reliably perform the winding up and down operation up to 1.1 times the rated load (W), and to reliably stop the winding operation up to 1.25 times the rated load. Therefore, it is important to detect overload based on the motor current value to determine the necessity of operating the electronic OLL, and the overload threshold for stopping the hoisting operation is initially set before the hoisting machine is shipped. Pre-shipment inspection is performed to do so. At that time, it may be necessary to adjust the setting of the overload threshold value due to individual differences in the hoisting machine.

In addition, if the customer who rented or purchased the hoisting machine wants to change the default overload threshold to a safer direction, or the power supply situation at the installation location of the hoisting machine (voltage drop due to power distribution, etc.) You may want to change the overload threshold depending on the situation.

Conventionally, there is an invention disclosed in Patent Document 1, for example, regarding overload detection of a hoisting motor. The present invention detects an overload by approximating the power supply voltage-input power characteristic of the hoisting motor (motor) with a straight line, and is very excellent in that the overload can be easily detected with a certain degree of accuracy.

Japanese Patent No. 2593270

However, there is a demand for improving the overload determination accuracy (detection accuracy) by approximating the initial setting to the actual overload (threshold value) as compared with the invention described in Patent Document 1. In addition, we want to continue to improve the judgment accuracy even if the overload threshold is changed.

Therefore, the present invention provides a method for determining an overload of a hoisting motor and a method for manufacturing a hoisting machine, which can perform overload determination with good determination accuracy and continue to have good determination accuracy even if the overload threshold value is changed. The purpose.

According to the first aspect of the present invention, the overload determination method for determining the overload of the hoisting motor is as follows.
Step A, which measures the relationship between input voltage and current by applying a reference overload to the reference hoisting motor,
Based on the measured value, the B step and the B step for deriving the reference overload determination threshold curve as the reference threshold for overload determination consisting of the reference function in which the current (i) is defined by the quadratic equation of the input voltage (v). ,
The C step for determining whether or not to change the reference overload determination threshold curve, and
When the reference overload determination threshold curve is not changed, the overload of the target hoisting motor is determined based on the reference overload determination threshold curve, and when the reference overload determination threshold curve is changed, the overload is determined. The D step of determining the overload of the target hoisting motor based on the corrected overload determination threshold curve composed of the quadratic equation obtained by correcting the intercept of the reference function, and
It is characterized by including.

Here, in the method for determining the overload of the hoisting motor of the present invention,
When the reference overload determination threshold curve is changed in the C step, the coefficient and intercept of the reference function are corrected based on the difference between the current values at the input voltages of the first load curve and the second load curve. Based on the corrected overload determination threshold curve consisting of the quadratic equation, the overload of the target hoisting motor is determined and the overload is determined.
The first load curve is the input voltage of the reference hoisting motor in the first load set to the lower limit load that guarantees the hoisting operation of the reference hoisting motor measured in step A. Calculated based on current measurements
The second load curve is the input voltage of the reference hoisting motor in the second load set to the lower limit load that guarantees the hoisting stop of the reference hoisting motor measured in step A. Calculated based on current measurements,
Is preferable.

Further, in the method for determining the overload of the hoisting motor of the present invention,
The input voltage region for determining the overload is divided into a low voltage side input voltage region and a high voltage side input voltage region having a voltage higher than the low voltage side input voltage region.
In the low voltage side input voltage region, the overload is determined by a method including the A step, the B step, the C step, and the D step.
In the high voltage side input voltage region,
With step A
Based on the measured value of the current, instead of the reference overload determination threshold curve, as a reference threshold for overload determination consisting of a reference function in which the current (i) is defined by the linear equation of the input voltage (v). B2 step to derive the reference overload threshold line and
A C2 step for determining whether or not to change the reference overload determination threshold line, and
When the reference overload determination threshold line is not changed, the overload of the target hoisting motor is determined based on the reference overload determination threshold line, and when the reference overload determination threshold line is changed, the overload is determined. The D2 step of determining the overload of the target hoisting motor based on the corrected overload determination threshold line corrected by correcting the reference overload determination threshold line, and
Is preferably included.

Further, according to the first aspect of the present invention, a method for manufacturing a hoisting machine including a hoisting motor and a microcomputer and having a function of determining an overload of the hoisting motor by the microcomputer is described.
A reference overload in which the current (i) is defined by the quadratic equation of the input voltage (v) based on the measured value obtained by measuring the relationship between the input voltage and the current in a state where various loads are applied to the reference hoisting motor. An implementation step of implementing a function of deriving the reference overload determination threshold curve as a reference threshold for overload determination in a microcomputer, which is a determination threshold curve.
The C step for determining whether or not to change the reference overload determination threshold curve, and
When changing the reference overload determination threshold curve, the reference overload determination threshold curve is changed to a corrected overload determination threshold curve composed of a quadratic equation obtained by correcting the intercept of the reference function, and the microcomputer is used. And the change steps to implement in
It is characterized by including.

Here, in the method for manufacturing the hoisting machine of the present invention,
The corrected overload determination threshold curve in the change step is obtained by correcting the coefficient and section of the reference function based on the difference between the current values at the input voltages of the first load curve and the second load curve.
The first load curve is set to a lower limit load that applies various loads to the reference hoisting motor, measures the relationship between the input voltage and the current, and guarantees the hoisting operation of the reference hoisting motor. Calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference under the load of
The second load curve is set to the lower limit load that guarantees the hoisting stop of the hoisting motor as the reference while measuring the relationship between the input voltage and the current by applying various loads to the hoisting motor as the reference. Calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference under the load of.
Is preferable.

Further, in the method for manufacturing the hoisting machine of the present invention,
The mounting step includes a low voltage side mounting step and a high voltage side mounting step.
In the low voltage side mounting step, the function of deriving the reference overload determination threshold curve is mounted on the microcomputer.
In the high voltage side mounting step, the reference overload in which the current (i) is defined by the linear equation of the input voltage (v) when the input voltage region for determining the overload is higher than the low voltage side mounting step. The function of deriving the reference overload threshold line, which is a threshold line and serves as a reference threshold for overload determination, is implemented in the microcomputer in place of the function of deriving the reference overload determination threshold curve. ,
The change step includes a low voltage side change step and a high voltage side change step.
In the low voltage side change step, the reference overload determination threshold curve is changed to the correction overload determination threshold curve and mounted on the microcomputer.
In the high voltage side change step, the reference overload determination threshold curve and the reference overload determination threshold straight line are corrected when the input voltage region for determining the overload is higher than the low voltage side change step. Change to the corrected overload judgment threshold straight line and mount it on the microcomputer.
Is preferable.

According to the method for determining the overload of the hoisting motor and the method for manufacturing the hoisting machine of the present invention, it is possible to determine the overload with high accuracy. Then, even when a situation occurs in which the overload threshold value is changed, it is possible to continue to accurately determine the overload of the hoisting motor.

It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is the figure which shows the hardware composition of the overload determination apparatus (winding machine) of a hoisting motor. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is the figure which shows the functional block of the overload determination apparatus of a hoisting motor. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is the figure which shows the reference overload determination threshold curve in various loads. It is a figure for demonstrating the processing flow of the overload determination method which concerns on Embodiment 1. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is explanatory drawing about the derivation of the reference overload determination threshold curve. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is the figure explaining the flow which derives the reference overload determination threshold curve. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is explanatory drawing concerning the change of the reference overload determination threshold curve. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is the figure which explains the processing flow concerning the change of the reference overload determination threshold curve. It is a figure for demonstrating the overload determination method which concerns on Embodiment 1, and is explanatory drawing about the correction overload determination threshold curve. It is a figure for demonstrating the overload determination method which concerns on Embodiment 2, and is the figure which shows the functional block of the overload determination apparatus of a hoisting motor. It is a figure for demonstrating the processing flow of the overload determination method which concerns on Embodiment 2. It is a figure for demonstrating the overload determination method which concerns on Embodiment 2. It is a figure for demonstrating the overload determination method which concerns on Embodiment 3.

Hereinafter, the method for determining the overload of the hoisting motor and the method for manufacturing the hoisting machine of the present invention will be described based on the embodiment shown in the figure. It should be noted that each drawing is a schematic view and does not necessarily accurately reflect the actual structure, appearance, etc.

[Embodiment 1]
1 to 9 are views for explaining an overload determination method for the hoisting motor 22 according to the first embodiment.

First, the entire hoisting machine 21 will be described.
FIG. 1 is a diagram showing a hardware configuration of an overload determination device 24 (winding machine 21) of the hoisting motor 22 used in the overload determining method according to the first embodiment. The hoisting motor 22 means a motor in a state of being assembled on the hoisting machine 21.
Here, the “overload” means a load that exceeds the permissible load for the hoisting motor 22. Which load is to be overloaded is not necessarily uniquely determined, and the manufacturer or user of the hoisting motor 22 (winding machine 21) comprehensively judges safety, usability, etc. and decides. .. Therefore, in the present specification, "load 〇〇%" may be referred to as "load 〇〇%" as it is, or may be referred to as "overload 〇〇%". The "load" refers to a force for rotating the shaft of the hoisting motor 22 or a force for stopping the rotation of the shaft, and is mainly a load. Hereinafter, for example, the rated load (W) is defined as 100% of the load, and 1.1 times the rated load (W) is defined as 110% of the load.

The hoisting machine 21 is an electric chain block. The hoisting machine 21 includes a hoisting electric motor (motor) 22 and winds up a chain and winds up a load 51 such as a load by axially rotating a road sheave connected to the hoisting electric motor 22 via a reduction mechanism. The hoisting machine 21 may be a rope hoist or winch that winds a wire rope by rotating a drum.

The hoisting machine 21 includes an operation switch 25 for operating the hoisting and lowering of the hoisting motor 22, an overload determining device 24 for determining whether the load 51 is overloaded, and a braking device for braking the hoisting motor 22. 26 is provided. The braking device 26 is, for example, a pull rotor brake that applies a brake when the power supply to the hoisting motor 22 is cut off by opening and closing the electric circuit between the power supply 52 and the hoisting motor 22.

The operation switch 25 is a push button switch. When the hoisting button switch is pressed, power is supplied from the power supply 52 to the hoisting motor 22 to wind the load 51. When the hoisting switch is released, the power supply to the hoisting motor 22 is cut off and hoisting is stopped.

The overload determination device 24 includes a CPU 29, a ROM 31, a memory 30, and a sensor 23.

The CPU 29 is incorporated in a microcomputer (microcomputer), and reads and executes a computer program (software) that describes instructions (processes) for the CPU 29.
The program is stored in the ROM 31 or the RAM 32 in advance.
The memory 30 includes a ROM 31 and a RAM 32. The CPU 29, ROM 31, RAM 32 and sensor 23 are connected by a BUS to form a microcomputer (microcomputer).

FIG. 2 is a diagram for explaining the overload determination method according to the first embodiment, and is a diagram showing a functional block of the overload determination device 24 of the hoisting motor 22.

The overload determination device 24 includes a sensor 23, a memory 30, an overload determination means 61, a reference overload determination threshold curve derivation means 62, a reference overload determination threshold curve change determination means 63, and a correction overload determination threshold curve derivation means 64. Be prepared.

The sensor 23 detects the input voltage detector 53 that detects the input voltage of the hoisting machine 21 (the hoisting motor 22) and the current that flows through the hoisting motor 22 with respect to the electric power supplied from the power supply 52 to the hoisting machine 21. The current detector 54 is provided.

The "overload determination means" 61 refers to a microcomputer that reads a program and executes a function of determining an overload.
The “reference overload determination threshold curve derivation means” 62 refers to a microcomputer that reads a program and executes a function of deriving a reference overload determination threshold curve.
The “reference overload determination threshold curve change determination means” 63 refers to a microcomputer that reads a program and executes a function of determining a change in the reference overload determination threshold curve.
The “correction overload determination threshold curve derivation means” 64 refers to a microcomputer that reads a program and executes a function of deriving a correction overload determination threshold curve.
The memory 30 stores the input voltage and the current value under a constant (over) load of the hoisting motor 22.
The braking device 26 includes a braking command means 71 that gives a braking command to the hoisting motor 22, and a braking mechanism 261 that receives and brakes the braking command.

[Reference overload judgment threshold curve]
The reference overload determination threshold curve will be described.
FIG. 3 is a diagram for explaining the overload determination method according to the first embodiment, and is a diagram showing a reference overload determination threshold curve of the hoisting motor 22 as a reference in the reference load, but this is a diagram at the same time. It is also a figure which shows the reference overload determination threshold curve in the hoisting motor 22. The same applies to other figures.

Here, the "reference hoisting motor" means a "hoisting motor on which measurement or the like is based". The "target hoisting motor" means a "target hoisting motor for overload determination". For example, when there are multiple hoisting motors of the same model number, the average or model hoisting motor among them is set as the "reference hoisting motor", and the relationship between the input voltage and the current is measured in advance. Find the characteristics of the hoisting motor. The hoisting motor that reflects this measurement result and is subject to overload judgment in pre-shipment inspection or the like is referred to as the "target hoisting motor". If it is the same type of hoisting motor 22 such as the hoisting motor 22 of the same model number, there is little need to measure it individually, and the reference overload determination threshold curve 1 is derived based on the measurement of the reference hoisting motor 22. Then, the overload of the target hoisting motor 22 may be determined.
In the following embodiments including the first embodiment, the "hoisting motor 22" does not strictly separate the "reference hoisting motor" and the "target hoisting motor".

The reference overload determination threshold curve 1 of FIG. 3 shows the relationship between the input voltage of the hoisting motor 22 and the current (value) flowing through the hoisting motor 22 under a predetermined load. The horizontal axis is the input voltage (v) and the vertical axis is the current (i).
The input voltage in the operating range is 340V (volt) to 460V. The input voltage in this range is the guaranteed use range of the hoisting motor 22. The rated voltage is 400V.

The curve of reference numeral 1 is a curve showing the relationship between each input voltage (340V, 360V, 380V, 400V, 420V, 440V, 460V) at a reference load of 117.5% and the current, and this is the curve in the present embodiment. Was set as the reference overload determination threshold curve 1. That is, a load of 117.5% is set as a threshold value, and a load of 117.5% or more is set as an overload.
Here, the "threshold value" means the minimum value to be overloaded. Also called a limit value or a critical value. The threshold is set to 117.5%, which is an intermediate value between the load of 125%, which should strictly prohibit hoisting and ensure safety, and the load of 110%, which allows hoisting, to give more consideration to safety. Because it was done. The applicant's shipping standard is that the overload threshold at the time of shipment from the factory is a load of 117.5%. However, the load of 117.5% is a guideline for the threshold value, and it is sufficient that the winding does not stop when the load is 110% or less and the winding stops in the range of the load of 110% to 125%, strictly 117. It is not necessary to stop the hoisting with a load of 5.5%.

Further, in FIG. 3, in addition to the load of 117.5% (curve of reference numeral 1), the relationship between the input voltage and the current (measured value) at loads of 100% and 125% is shown in the curve of reference numeral 100 and the curve of reference numeral 125, respectively. It is shown by the overload judgment threshold curve. As can be seen from each curve, the increasing / decreasing tendency (motor characteristics) of the input voltage-current at each load can be read.
Actually, the quadratic curve of the load 117.5% is obtained in advance, and the current values of at least the input voltages 340V, 400V and 460V at the loads 100% and 125% are actually measured and stored in the memory 30. Thereby, if necessary, a rough curve of the motor characteristics of the hoisting motor 22 as a reference at a load of 100% and 125% can be drawn. Then, based on the approximate curves of the load of 100% and 125%, the approximate current value at an arbitrary input voltage at, for example, the load of 110% is obtained from the proportional relationship of the difference between the load of 100% and the load of 117.5%. be able to.

In the present embodiment, the load of 117.5% is set as the reference load, but when the reference load (overload threshold) at the time of shipment from the factory is set to, for example, the load of 115%, the load obtained in advance from the measured value is the same as above. The 115% quadratic curve is used as the reference overload determination threshold curve.

[Processing flow of overload judgment method]
FIG. 4 is a diagram for explaining a processing flow of the overload determination method according to the first embodiment.
In the overload determination method for determining the overload of the hoisting motor 22 of the first embodiment, first, the reference load 51 is applied to the reference hoisting motor 22 (1.175 W (117.5%) in the present embodiment). To measure the relationship between the input voltage and the current (value) in advance (steps S1 and A).
The measurement of the relationship between the input voltage and the current is performed by the input voltage detector 53 and the current detector 54.
The measurement result is stored in the memory 30. "Measurement" was performed by actual measurement. The measured value is an actually measured value.

Next, the reference overload determination threshold curve deriving means 62 is an overload determination including a reference function in which the current (i) is defined by the quadratic equation of the input voltage (v) based on the measured value stored in the memory 30. The reference overload determination threshold curve 1 (approximate curve) as the reference threshold for the above is derived (steps S2 and B).
Here, the "quadratic equation" refers to an equation in which the current of the hoisting motor 22 is expressed by a polynomial of degree 2 of the input voltage.

Next, the reference overload determination threshold curve change determination means 63 determines whether or not to change the reference overload determination threshold curve 1 (steps S3 and C). It should be noted that this determination is made humanly and is not automatically made by the overload determination device 24. The case of deciding to change is the case of intentionally lowering the threshold value when the customer wants to move to the safe side at the request of the customer, or even if the threshold value is set to 117.5% due to the variation of individual hoisting machines. It is assumed that the threshold is raised when the winding stops at a load of 110% or less, or the threshold is lowered when the winding does not stop in the range of 110% to 125% of the load.

In step S4 (step D), when the reference overload determination threshold curve 1 (overload threshold value) is not changed, the overload of the target hoisting motor 22 is determined based on the reference overload determination threshold curve 1 (step S4 (D step)). Step S4-1).
When changing the reference overload determination threshold curve 1 (overload threshold value), the overload of the target hoisting motor 22 is based on the corrected overload determination threshold curve 2 consisting of the quadratic equation obtained by correcting the intercept of the reference function. Is determined (step S4-2).
The overload determining means 61 includes an input voltage (value) detected by the input voltage detector 53, a current value detected by the current detector 54, and a reference overload derived by the reference overload determination threshold curve deriving means 62. The above process (overload determination) is performed based on the determination threshold curve 1.

[Derivation of reference overload judgment threshold curve]
The derivation of the reference overload determination threshold curve 1 will be described with reference to FIGS. 5 to 6.
The reference threshold value for overload determination was 117.5%.
The reference overload determination threshold curve 1 is mainly derived by the reference overload determination threshold curve derivation means 62.

As shown in FIG. 5, a load of 117.5% was actually applied as a reference load on the reference hoisting motor 22, and the relationship between each input voltage of the hoisting motor 22 and the current (value) was measured. Specifically, the measurement was performed every 20V from 340V in the range of the input voltage of 340V to 460V. 121 is each measured value. The measured value 121 is stored in the memory 30.
Reference numeral 1 indicates a reference overload determination threshold curve (approximate curve) obtained from a plurality of measured values 121 by a mathematical method such as the least squares method.

FIG. 6 is a diagram for explaining the overload determination method according to the first embodiment, and is a diagram for explaining a flow for deriving the reference overload determination threshold curve 1.

First, the reference overload threshold is determined. Here, the reference overload threshold was determined to be 117.5% (step S21).

Next, the reference overload determination threshold curve deriving means 62 is a quadratic expression.
i ＝ a ・ v ² + b ・ v + c… (1)
i: current (value), v: input voltage (value),
a (coefficient, ≠ 0), b (coefficient), c (intercept): A constant is prepared (step S22).
This is a reference function in which the current (i) is defined by the quadratic equation of the input voltage (v), and represents the reference overload determination threshold curve 1 as the reference threshold for the overload determination.

Next, the reference overload determination threshold curve deriving means 62 reads out the measured values 121 of the input voltage and the current value at the reference threshold overload (117.5%) from the memory 30 (step S23).

Next, in step 24, a plurality of combinations of each input voltage and current value at the reference threshold overload (117.5%) are substituted into the above-mentioned quadratic expression whose constant is undecided, and the constant a of the approximate curve is substituted. (Coefficient), b (coefficient) and c (section) are obtained, and a quadratic equation is created (step 25).

Then, as in the above equation (1), the "reference overload determination" (as the reference threshold value for the overload determination) is composed of the reference function in which the current (i) is defined by the quadratic equation of the input voltage (v). Based on the "threshold curve 1", the overload of the target hoisting motor 22 is determined. Specifically, when the load 51 is lifted at a constant power supply voltage, the current value flowing through the hoisting motor 22 rises sharply and then decreases slightly to settle to a substantially constant current value. When this constant current value exceeds this reference threshold value, it is determined that the load is overloaded, the power supply is cut off, and the hoisting motor 22 is stopped. As a result, regardless of the input voltage in the usage range, the overload determination with higher determination accuracy becomes possible as compared with the overload determination based on the threshold value based on the approximate straight line described in the prior art document.

[Change of reference overload judgment threshold curve]
A case where the reference overload determination threshold curve 1 is changed will be described with reference to FIGS. 7 to 9.

FIG. 7 is a diagram for explaining the overload determination method according to the first embodiment, and is an explanatory diagram relating to the change of the reference overload determination threshold curve 1.
In the above, with reference to FIGS. 5 to 6, the reference threshold value for overload determination is set to 117.5%, and the derivation of the reference overload determination threshold value curve 1 has been described.
However, it is assumed that the reference threshold value is changed (corrected) to 115% after shipment, for example, in response to a request to improve the safety of the customer. In that case, the overload of the target hoisting motor 22 is determined based on the corrected overload determination threshold curve 2 (2-115) in which the reference threshold value (load) is 115%.

FIG. 7 shows a reference overload determination threshold curve 1 when the reference threshold is 117.5% and a corrected overload determination threshold curve 2 (2-115) when the reference threshold is 115%. There is.
The corrected overload determination threshold curve 2 (2-115) basically passes through the reference overload determination threshold curve 1 with a load of 115% and a current value of a rated voltage (400 V) as shown in FIG. In addition, it is a curve translated in the vertical axis (y-axis) direction. The current value at the rated input voltage at a load of 115% (Z%) is obtained from the proportional relationship between the current value of the load of 100% and the current value of the load of 117.5% stored in the memory 30.
FIG. 8 is a diagram for explaining the overload determination method according to the first embodiment, and is a diagram for explaining the processing flow regarding the change of the reference overload determination threshold curve 1 in more detail.
FIG. 9 is a diagram for explaining the overload determination method according to the first embodiment, and is an explanatory diagram relating to the corrected overload determination threshold curve 2.

The correction overload determination threshold curve 2 is derived by the correction overload determination threshold curve derivation means 64 that changes (corrects) the reference overload determination threshold curve 1. The overload determination means 61 performs the overload determination.

This will be described according to the flow of FIG.
First, the "overload" 117.5% of the reference overload determination threshold curve 1 (overload 117.5%) and the "overload" Z% (changed) of the correction overload determination threshold curve 2 to be obtained. It is determined whether the difference from the overload%) determination threshold value is within a certain range (for example, within 5%) (step S41).
If YES, the process proceeds to step 42. For example, when a certain range is 5%, if Z = 115 (overload 115%), 117.5-115 = 2.5 (%), and if it is within 5%, YES.
In step 42, the reference overload determination threshold curve 1 is translated in the y-axis direction (longitudinal direction) so as to pass the measured current value at the rated voltage (400 V) at the overload Z% (intercept c is changed). ..
Then, the curve obtained by translating the reference overload determination threshold curve 1 is set as the corrected overload determination threshold curve 2 (corrected overload determination threshold curve 2-115 at 115% overload) (step 43). FIG. 7 is a diagram illustrating the above processing and has been described above.

If NO (if the difference is not within a certain range), the process proceeds to step 44. For example, when a certain range is 5%, if Z = 110 (overload 110%), 117.5-110 = 7.5 (%), which exceeds 5% and is NO.
In step 44, the distance between the curve 1 (overload 117.5%) and the curve 100 (rated load 100%) in the y-axis direction is (117.5-Z) :( Z-100). Draw a proportionally divided (proportional distribution) curve (a curve that passes through the proportionally divided points).
Then, the apportioned curve is referred to as the corrected overload determination threshold curve 2 (corrected overload determination threshold curve 2-110 at 110% overload).

FIG. 9 is an explanatory diagram in the case of NO (when the difference is not within a certain range). The overload of the corrected overload determination threshold curve 2 (2-110) to be obtained is 110%, and the difference from the overload 117.5% of the reference overload determination threshold curve 1 exceeds 5%.
In this case, the distance between the curve 1 (overload 117.5%) and the curve 100 (rated load 100%) in the y-axis direction is (117.5-110) :( 110-100) = 7. . Draw a curve (a curve that passes through the proportionally divided points) that is proportionally divided (proportional distribution) at 5:10. In FIG. 9, at input voltages of 340V, 400V and 460V, a curve passing through a point obtained by apportioning between curves 1 and 100 to 7.5: 10.
Then, the above-proportioned curve was used as the corrected overload determination threshold curve 2 (corrected overload determination threshold curve 2-110 at 110% overload).

Since the above processing is performed, it is possible to continuously determine the overload of the hoisting motor 22 with good determination accuracy even if the overload threshold value is changed.

The manufacturing method for manufacturing the hoisting machine 21 capable of such overload determination by the above-mentioned microcomputer is as follows.
That is, the current (i) is defined by the quadratic equation of the input voltage (v) as described in the above-mentioned B step (step S2) based on the measured value measured in advance in the above-mentioned A step (step S1). The function of deriving the reference overload determination threshold curve as the reference threshold for overload determination, which is the reference overload determination threshold curve, is implemented in the above-mentioned microcomputer (implementation step).

Further, as in step C (step S3) above, it is determined whether or not to change the reference overload determination threshold curve.

Then, when the reference overload determination threshold curve is changed in the above C step (step S3), the reference overload determination threshold curve is changed to the intercept of the reference function as described in the above step S4-2. Is changed to the corrected overload determination threshold curve consisting of the corrected quadratic equation and implemented in the microcomputer (change step).
If the reference overload determination threshold curve is not changed in step C (step S3), the reference overload determination threshold curve is left as it is implemented.

In this way, it is possible to satisfactorily manufacture the hoisting machine 21 capable of determining the overload of the hoisting motor 22 with good determination accuracy as described above. In particular, since the curve for overload determination can be changed from the reference overload determination threshold curve to the corrected overload determination threshold curve before the hoisting machine 21 is shipped, individual variations of the product can be absorbed satisfactorily. Since the hoisting machine 21 can be shipped in this state, the quality can be stabilized.

[Embodiment 2]
The overload determination method according to the second embodiment will be described with reference to FIGS. 10 to 12.

The overload determination method of the second embodiment is the overload determination method described in the first embodiment, and the input voltage region for determining the overload is a low voltage side input voltage region and a higher voltage than the low voltage side input voltage region. It is divided into a voltage side input voltage region, and in the low voltage side input voltage region, overload is determined by a method including A step, B step, C step and D step, and in the high voltage side input voltage region, A step and current. Based on the measured value of, instead of the reference overload determination threshold curve, the reference overload as the reference threshold for overload determination consisting of the reference function in which the current (i) is defined by the linear equation of the input voltage (v). The B2 step for deriving the threshold line, the C2 step for determining whether to change the reference overload judgment threshold line, and the target based on the reference overload judgment threshold line when the reference overload judgment threshold line is not changed. When the overload of the hoisting motor is determined and the reference overload determination threshold line is changed, the overload of the target hoisting motor is based on the corrected overload judgment threshold line corrected by the reference overload judgment threshold line. D2 step to judge the load and
including.

On the high voltage side where the input voltage is high in the input voltage region, the current value flowing through the hoisting motor 22 may change little even if the load is changed due to the start of magnetic saturation of the hoisting motor 22 or the like. Therefore, the input voltage region for determining overload is divided into a low voltage side input voltage region and a high voltage side input voltage region having a higher voltage than the low voltage side input voltage region. The overload of the target hoisting motor is determined based on the curve, and the overload is determined by the reference overload threshold linear line instead of the reference overload determination threshold curve in the high voltage side input voltage region.
By doing so, the risk of erroneous determination of overload is reduced.

FIG. 10 is a diagram for explaining the overload determination method according to the second embodiment, and is a diagram showing a functional block of the overload determination device 24 of the hoisting motor 22.

The overload determination device 24 differs from the diagram (a diagram showing the functional block of the overload determination device 24 of the hoisting motor 22) for explaining the overload determination method according to the first embodiment of FIG. 2. 23, memory 30, overload determination means 61, reference overload determination threshold curve derivation means 62, reference overload determination threshold curve change determination means 63, correction overload determination threshold curve derivation means 64, and reference overload determination threshold. The point is that the linear derivation means 65, the reference overload determination threshold linear change determination means 66, and the correction overload determination threshold linear derivation means 67 are provided. In addition, the configuration shown in FIG. 10 is different from the configuration shown in FIG. 2 in that it includes a sounding device 27 that generates a predetermined sound and an interface 28 for connecting to an external device to transmit and receive information.

Here, the “reference overload determination threshold linear derivation means” 65 refers to a microcomputer that reads a program and executes a function of deriving the reference overload determination threshold straight line 3.
The “reference overload determination threshold value linear change determination means” 66 refers to a microcomputer that reads a program and determines whether or not to change the reference overload determination threshold value linear line 3.
The “correction overload determination threshold linear derivation means” 67 refers to a microcomputer that reads a program and executes a function of deriving the correction overload determination threshold straight line 4.

FIG. 11 is a diagram for explaining a processing flow of the overload determination method according to the second embodiment. FIG. 12 is a diagram for explaining an overload determination method according to the second embodiment.

First, it is determined whether or not to divide the input voltage region (step S51). For example, when the power supply voltage is 420 V or more, it may be decided to uniformly divide the input voltage region.
When the input voltage region is divided (step S51, division: YES), the input voltage region is divided into a low voltage side input voltage region and a high voltage side input voltage region (step S52).
In the second embodiment, as shown in FIG. 12, the low voltage side input voltage region is set to 340V to 420V, and the high voltage side input voltage region is set to 420V to 460V. This is because the current value flowing through the hoisting motor 22 at around 420 V begins to change less even if the load is changed.

Next, the input voltage region is divided into a low voltage side input voltage region and a high voltage side input voltage region having a higher voltage than the low voltage side input voltage region (step S53), and the processing flow is different for each.
In the low voltage side input voltage region, the processes of steps S54 to S57 are performed.
In the high voltage side input voltage region, the processes of steps S58 to S61 are performed.

In the low voltage side input voltage region, first, the sensor 23 measures the relationship between the input voltage and the current of the hoisting motor 22 at a constant load 51 (steps S54 and A).

Next, the reference overload determination threshold curve deriving means 62 is for overload determination including a reference function in which the current (i) is defined by the quadratic equation of the input voltage (v) based on the measured value 121 of the current. A reference overload determination threshold curve 1 (overload 117.5%) as a reference threshold is derived (step B).

Next, based on the reference overload determination threshold change command or the like, the reference overload determination threshold curve change determination means 63 determines whether or not to change the reference overload determination threshold curve 1 (steps S56 and C). ..

Next, when the reference overload determination threshold curve 1 is not changed, the overload determination means 61 determines the overload of the target hoisting motor 22 based on the reference overload determination threshold curve 1 (step S571, step S571, D step).

When the reference overload determination threshold curve 1 is changed, the target is set based on the correction overload determination threshold curve 2 derived by the correction overload determination threshold curve derivation means 64, which consists of a quadratic equation obtained by correcting the intercept of the reference function. The overload of the hoisting motor 22 is determined (step S57-2).
For example, when the overload determination threshold is changed from overload 117.5% to overload 112.5%, 117.5% -112.5% = 5%, which is within 5%, so that curve 1 (overload) Based on the corrected overload determination threshold curve 2 (2-112.5) in which the load (117.5%) is moved in parallel in the y-axis direction so as to pass through the current value flowing at the overload of 112.5% at the rated input voltage of 400 V. judge.
Reference numeral 100 in FIG. 12 is a load curve at a rated load (100%).
The overload determining means 61 includes an input voltage (value) detected by the input voltage detector 53, a current value detected by the current detector 54, and a reference overload derived by the reference overload determination threshold curve deriving means 62. The above processing is performed based on the determination threshold curve 1.

In the high voltage side input voltage region, first, the sensor 23 measures the relationship between the input voltage and the current in the constant load 51 of the hoisting motor 22 (steps S58 and A2).

Next, the reference overload determination threshold linear derivation means 65 is a reference for overload determination including a reference function in which the current (i) is defined by the linear equation of the input voltage (v) based on the measured value 121 of the current. A reference overload determination threshold line 3 as a threshold is derived (steps S58 and B2).

[Drivation of reference overload judgment threshold straight line]
The reference overload determination threshold straight line 3 is derived by the reference overload determination threshold linear derivation means 65.
The reference overload determination threshold value straight line 3 is a reference overload threshold value straight line as a reference threshold value for overload determination consisting of a reference function that defines the current (i) in the linear equation of the input voltage (v), and is expressed by the following equation. expressed.
i = d ・ v + e
However, d (coefficient, ≠ 0), e (intercept): (d and e are collectively called a constant)
The "linear expression" is an expression in which the current of the hoisting motor 22 is expressed by a polynomial of degree 1 of the input voltage.

Since the reference overload determination threshold value straight line 3 is a straight line, it can be easily derived as compared with the reference overload determination threshold value curve 1 which is a curve.
Since the reference overload determination threshold line 3 and the reference overload determination threshold curve 1 both have a load of 117.5%, the low voltage side input voltage region (340V to 420V) and the high voltage side input voltage region (420V). ~ 460V), the input voltage must be 420V, and the current value must be the same, and both must be continuous. Therefore, the reference overload determination threshold line 3 is a straight line passing through this point.

If another point is determined, the reference overload determination threshold line 3 can be derived. One point is also determined by determining the current value at the highest voltage (460V) in the high voltage side input voltage region (420V to 460V). It is determined in consideration of the current value characteristics in the high voltage side input voltage region (420V to 460V). Here, the current value is set to be equal to or higher than the current value at the input voltage of 460 V of the reference overload determination threshold curve 1.

When the reference overload determination threshold line 3 is not changed, the overload determination means 61 determines the overload of the target hoisting motor 22 based on the reference overload determination threshold value line 3 (steps S61-1, D2). Step).
When the reference overload determination threshold value straight line 3 is changed, the hoisting motor 22 to be targeted based on the correction overload determination threshold value straight line 4 composed of the linear expression corrected (derived) by the correction overload determination threshold value linear derivation means 67. (Step S61-2, D2 step).
Reference numeral 100 in FIG. 9 is a load curve at a rated load (100%).

[Change of reference overload judgment threshold straight line]
Next, the reference overload determination threshold value linear change determination means 66 determines whether or not to change the reference overload determination threshold value linear line 3 in accordance with the change of the reference threshold value or the like (steps S60 and C2).
When the reference threshold is changed and the reference overload determination threshold curve 1 is corrected to the corrected overload determination threshold curve 2, in many cases, the reference overload determination threshold straight line 3 is also corrected to the corrected overload determination threshold straight line 4. ..
In the present embodiment, the reference overload determination threshold curve 1 (load 117.5%) is corrected by moving the curve 1 in parallel in the y-axis direction so as to pass the measured current value of the load 112.5% at the rated voltage of 400 V. As the overload determination threshold curve 2 (2-112.5, load 112.5%) is corrected, the reference overload determination threshold line 3 (load 117.5%) is also corrected to the corrected overload determination threshold line 4 (load 117.5%). The load was corrected to 112.5%).

Since the correction overload determination threshold value straight line 4 is a straight line, it can be easily derived as compared with the correction overload determination threshold value curve 2 which is a curve.
Since the corrected overload determination threshold line 4 and the corrected overload determination threshold curve 2 both have a load of 112.5%, the low voltage side input voltage region (340V to 420V) and the high voltage side input voltage region (420V). ~ 460V), the input voltage must be 420V, and the current value must be the same, and both must be continuous. Therefore, the correction overload determination threshold line 4 is a straight line passing through this point.

If another point is determined, the reference overload determination threshold line 3 can be derived. One point is also determined by determining the current value at the highest voltage (460V) in the high voltage side input voltage region (420V to 460V). It is determined in consideration of the current value characteristics in the high voltage side input voltage region (420V to 460V). Here, the current value is set to be equal to or higher than the current value at the input voltage of 460 V of the reference overload determination threshold curve 1.

The overload determination means 61 includes an input voltage (value) detected by the input voltage detector 53, a current value detected by the current detector 54, and a straight line 3 derived by the reference overload determination threshold linear derivation means 65. Alternatively, it is determined whether or not there is an overload based on the straight line 4 derived by the correction overload determination threshold linear derivation means 67.

When the input voltage region is not divided (step S51, division: NO), the process of FIG. 4 is performed.
Since the above is performed, it is possible to make an overload judgment with a judgment accuracy that is closer to the actual overload, and even if the overload threshold value is changed, it is possible to continue to make an overload judgment of the hoisting motor 22 with a good judgment accuracy. It becomes.
Further, the input voltage region is divided into a low voltage side input voltage region and a high voltage high voltage side input voltage region, and the overload is determined by the reference overload determination threshold curve 1 and the reference overload threshold linear line, respectively. The risk of misjudgment can be further reduced.

The manufacturing method for manufacturing the hoisting machine 21 capable of such overload determination by the above-mentioned microcomputer is as follows.

That is, the mounting step, the C step, and the changing step as described in the first embodiment are executed. Here, in the second embodiment, the above-mentioned mounting step includes a low-voltage side mounting step and a high-voltage side mounting step.
Then, in the low voltage side mounting step, the function of deriving the reference overload determination threshold curve is mounted on the microcomputer.
On the other hand, in the high voltage side mounting step in which the input voltage region for determining the overload is the high voltage side rather than the low voltage side mounting step, as described above, the current (i) is calculated by the linear expression of the input voltage (v). The function of deriving the defined reference overload threshold linear as the reference threshold for overload determination is implemented in the microcomputer instead of the function of deriving the reference overload determination threshold curve. do.

Further, in the second embodiment, the above-mentioned change step includes a low-voltage side change step and a high-voltage side change step.
Then, in the low voltage side change step, the reference overload determination threshold curve is changed to the correction overload determination threshold curve and implemented in the microcomputer.
On the other hand, in the high voltage side change step, when the input voltage region for determining the overload is higher than the low voltage side change step, the reference overload determination threshold curve is corrected and the reference overload determination threshold straight line is corrected. Change to the judgment threshold straight line and implement it on the microcomputer.

In this case, it is possible to make an overload determination with a determination accuracy that is closer to the actual overload, and it is possible to continue to make an overload determination of the hoisting motor 22 with a good determination accuracy even if the overload threshold value is changed. The hoisting machine 21 can be manufactured. Moreover, in the hoisting machine 21 manufactured, when the input voltage region is the low voltage side input voltage region, the overload is determined by the reference overload determination threshold curve. On the other hand, when the input voltage region is the high voltage side input voltage region, the overload is determined by the reference overload determination threshold line. Therefore, it is possible to manufacture the hoisting machine 21 which can further reduce the risk of erroneous determination of overload.

[Embodiment 3]
FIG. 13 is a diagram for explaining an overload determination method according to the third embodiment.

In the overload determination method of the third embodiment, the method of deriving the reference overload determination threshold curve 1 is changed by the overload determination method described in the first embodiment.
That is, in the third embodiment, when the reference overload determination threshold curve 1 is changed in the C step, the lower limit load that guarantees the hoisting operation of the hoisting motor as the reference measured in the A step is set. The first load is based on the measured values of the current at each input voltage of the reference hoisting motor in the second load set to the lower limit load that guarantees the hoisting stop of the reference hoisting motor. The curve and the second load curve are obtained, and the target volume is based on the corrected overload determination threshold curve 2 consisting of a quadratic equation in which the coefficient of the reference function and the section are corrected based on the difference in the current value at each input voltage of both curves. Judge the overload of the upper motor.

In FIG. 13, reference numeral 13 is a first load curve at the first load (load 125%) set to the lower limit load that guarantees the hoisting stop of the hoisting motor 22. If the current value exceeds this curve, the hoisting operation must be stopped.
Reference numeral 14 indicates a second load curve at the second load (load 112.5%) set to the lower limit load that guarantees the hoisting operation of the hoisting motor 22. The hoisting operation is guaranteed at a load of 112.5%, and the hoisting motor 22 must perform the hoisting operation (it must not be stopped).

The first load curve 13 and the second load curve 14 are curves obtained based on the measured value 121 of the current at each input voltage of the hoisting motor 22 as a reference.
These curves were obtained in the same manner as described with reference to FIGS. 5 to 6 in the first embodiment.

In the third embodiment, a corrected overload determination threshold curve 2 consisting of a quadratic equation obtained by correcting the coefficient and intercept of the reference function is derived based on the difference between the current values at the input voltages of the curves 13 and 14, and the curve thereof. Based on the above, the overload of the target hoisting motor 22 is determined.

As shown in FIG. 13, there is a difference between the curve 13 and the curve 14. Therefore, an arbitrary curve 1A passing between these curves 13 and 14 was derived, and this was used as a reference overload determination threshold curve (between load 110% and 125%).

In this way, the reference overload determination threshold curve (between 110% and 125% of the load) 1A can be easily created. Further, since this curve 1A is a curve between the curve 13 (load 125%) and the curve 14 (load 110%), the operation is guaranteed at the load 110%, and the operation is stopped at the load 125%.

The manufacturing method for manufacturing the hoisting machine 21 capable of such overload determination by the above-mentioned microcomputer is as follows.
That is, the mounting step, the C step, and the changing step as described in the first embodiment are executed. Here, in the third embodiment, the corrected overload determination threshold curve in the above change step sets the coefficient and section of the reference function based on the difference between the current values at the input voltages of the first load curve and the second load curve. It is a corrected one.
Further, the first load curve (indicated by reference numeral 13 in FIG. 13) applies various loads to the reference hoisting motor, measures the relationship between the input voltage and the current, and measures the hoisting operation of the reference hoisting motor. It is calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference in the first load set to the guaranteed lower limit load.
Further, the second load curve is set to a lower limit load that applies various loads to the reference hoisting motor, measures the relationship between the input voltage and the current, and guarantees the hoisting stop of the reference hoisting motor. It is calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference in the second load.

In this case, as described above, the reference overload determination threshold curve (between load 110% and 125%) 1A is a curve between curve 13 (load 125%) and curve 14 (load 110%). Therefore, it is possible to manufacture the hoisting machine 21 in which the operation is guaranteed at a load of 110% and the operation is stopped at a load of 125%.

[Embodiment 4]
In FIG. 13, the curve 13 is a load curve with a load of 125% (a load that absolutely needs to be stopped) as in the third embodiment, but the curve 14 is a load curve with a load of 115%. The load of 115% is a load of 110% or more for which the hoisting operation is guaranteed, and is a load on which the hoisting operation of the hoisting motor 22 may be stopped. This is mainly determined by the manufacturer and user of the hoisting motor 22 (hoisting machine 21) in consideration of the convenience, safety and the like of the hoisting machine 21.
Only the curve 14 was changed, and the other parts were the same as in the third embodiment, and the reference overload determination threshold curve 1A was set as a curve between the curve 13 with a load of 125% and the curve 14 with a load of 110%.
A part of the reference overload determination threshold curve 1A may overlap the curve 13 or the curve 14.

In this way, the reference overload determination threshold curve 1B can be easily created.
It is possible to easily respond to the user's request when the overload determination based on the reference overload determination threshold curve 1A is not strictly 117.5% but somewhere between the load 110% and the load 125%.

Although the present invention has been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment. It can be implemented in various forms as long as it does not deviate from the purpose.

1 ... Reference overload determination threshold curve (load 117.5%), 1A ... Reference overload determination threshold curve (between load 110% and 125%), 2 ... Corrected overload determination threshold curve, 2-110 ... Corrected overload Judgment threshold curve (overload 110%), 2-112.5 ... Corrected overload judgment threshold curve (overload 112.5%), 2-115 ... Corrected overload judgment threshold curve (overload 115%), 3 ... Reference overload determination threshold line (overload 117.5%), 4 ... Reference overload determination threshold line (load 112.5%), 13 ... first load curve (load 125%), 14 ... second load curve (load) Load 110%), 21 ... hoisting machine, 22 ... hoisting motor, 23 ... sensor, 24 ... overload determination device, 25 ... operation switch, 26 ... braking device, 29 ... CPU, 30 ... memory, 31 ... ROM, 32 ... RAM, 51 ... Load, 52 ... Power supply, 53 ... Input voltage detector, 54 ... Current detector, 61 ... Overload determination means, 62 ... Reference overload determination threshold curve derivation means, 63 ... Reference overload determination threshold Curve change determination means, 64 ... Corrected overload determination threshold curve derivation means, 65 ... Reference overload determination threshold linear derivation means, 66 ... Reference overload determination threshold linear change determination means, 67 ... Corrected overload determination threshold linear derivation means, 71 ... Braking command means, 100 ... Load curve (rated load 100%), 121 ... Measured value (actual measurement value), 125 ... Overload determination threshold line (overload 125%), 261 ... Braking mechanism

Claims (6)

This is an overload determination method for determining the overload of the hoisting motor.
Step A, which measures the relationship between input voltage and current by applying various loads to the reference hoisting motor,
Based on the measured value, the B step and the B step for deriving the reference overload determination threshold curve as the reference threshold for overload determination consisting of the reference function in which the current (i) is defined by the quadratic equation of the input voltage (v). ,
The C step for determining whether or not to change the reference overload determination threshold curve, and
When the reference overload determination threshold curve is not changed, the overload of the target hoisting motor is determined based on the reference overload determination threshold curve, and when the reference overload determination threshold curve is changed, the overload is determined. The D step of determining the overload of the target hoisting motor based on the corrected overload determination threshold curve composed of the quadratic equation obtained by correcting the intercept of the reference function, and
A method for determining an overload of a hoisting motor, which comprises. In the method for determining an overload of a hoisting motor according to claim 1,
When the reference overload determination threshold curve is changed in the C step, the coefficient and intercept of the reference function are corrected based on the difference between the current values at the input voltages of the first load curve and the second load curve. Based on the corrected overload determination threshold curve consisting of the quadratic equation, the overload of the target hoisting motor is determined and the overload is determined.
The first load curve is the input voltage of the reference hoisting motor in the first load set to the lower limit load that guarantees the hoisting operation of the reference hoisting motor measured in step A. Calculated based on current measurements
The second load curve is the input voltage of the reference hoisting motor in the second load set to the lower limit load that guarantees the hoisting stop of the reference hoisting motor measured in step A. Calculated based on current measurements,
A method for determining an overload of a hoisting motor, which is characterized in that. In the method for determining an overload of a hoisting motor according to claim 1 or 2.
The input voltage region for determining the overload is divided into a low voltage side input voltage region and a high voltage side input voltage region having a voltage higher than the low voltage side input voltage region.
In the low voltage side input voltage region, the overload is determined by a method including the A step, the B step, the C step, and the D step.
In the high voltage side input voltage region,
With step A
Based on the measured value of the current, instead of the reference overload determination threshold curve, as a reference threshold for overload determination consisting of a reference function in which the current (i) is defined by the linear equation of the input voltage (v). B2 step to derive the reference overload threshold line and
A C2 step for determining whether or not to change the reference overload determination threshold line, and
When the reference overload determination threshold line is not changed, the overload of the target hoisting motor is determined based on the reference overload determination threshold line, and when the reference overload determination threshold line is changed, the overload is determined. The D2 step of determining the overload of the target hoisting motor based on the corrected overload determination threshold line corrected by correcting the reference overload determination threshold line, and
A method for determining an overload of a hoisting motor, which comprises. In a method for manufacturing a hoisting machine, which comprises a hoisting motor and a microcomputer and has a function of determining an overload of the hoisting motor by the microcomputer.
A reference overload in which the current (i) is defined by the quadratic equation of the input voltage (v) based on the measured value obtained by measuring the relationship between the input voltage and the current in a state where various loads are applied to the reference hoisting motor. An implementation step of implementing a function of deriving the reference overload determination threshold curve as a reference threshold for overload determination in a microcomputer, which is a determination threshold curve.
The C step for determining whether or not to change the reference overload determination threshold curve, and
When changing the reference overload determination threshold curve, the reference overload determination threshold curve is changed to a corrected overload determination threshold curve composed of a quadratic equation obtained by correcting the intercept of the reference function, and the microcomputer is used. And the change steps to implement in
A method for manufacturing a hoisting machine, which comprises. In the method for manufacturing a hoist according to claim 4,
The corrected overload determination threshold curve in the change step is obtained by correcting the coefficient and section of the reference function based on the difference between the current values at the input voltages of the first load curve and the second load curve.
The first load curve is set to a lower limit load that applies various loads to the reference hoisting motor, measures the relationship between the input voltage and the current, and guarantees the hoisting operation of the reference hoisting motor. Calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference under the load of
The second load curve is set to the lower limit load that guarantees the hoisting stop of the hoisting motor as the reference while measuring the relationship between the input voltage and the current by applying various loads to the hoisting motor as the reference. Calculated based on the measured value of the current at the input voltage of the hoisting motor as the reference under the load of.
A method of manufacturing a hoisting machine, which is characterized in that. In the method for manufacturing a hoist according to claim 4 or 5.
The mounting step includes a low voltage side mounting step and a high voltage side mounting step.
In the low voltage side mounting step, the function of deriving the reference overload determination threshold curve is mounted on the microcomputer.
In the high voltage side mounting step, the reference overload in which the current (i) is defined by the linear equation of the input voltage (v) when the input voltage region for determining the overload is higher than the low voltage side mounting step. The function of deriving the reference overload threshold line, which is a threshold line and serves as a reference threshold for overload determination, is implemented in the microcomputer in place of the function of deriving the reference overload determination threshold curve. ,
The change step includes a low voltage side change step and a high voltage side change step.
In the low voltage side change step, the reference overload determination threshold curve is changed to the correction overload determination threshold curve and mounted on the microcomputer.
In the high voltage side change step, the reference overload determination threshold curve and the reference overload determination threshold straight line are corrected when the input voltage region for determining the overload is higher than the low voltage side change step. Change to the corrected overload judgment threshold straight line and mount it on the microcomputer.
A method of manufacturing a hoisting machine, which is characterized in that.

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