JP4413686B2 - DC motor restraint current calculation method, DC motor manufacturing method, and DC motor manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for calculating a binding current for a DC motor, a method for manufacturing a DC motor, and a DC motor manufacturing apparatus.

  The direct current motor is tested whether or not each characteristic satisfies the user's demand at the time of manufacture, and a product that passes the test is regarded as a product. Therefore, each characteristic of the DC motor is measured at the time of manufacture. As a characteristic of the DC motor, there is a rotational speed / motor current value-torque characteristic shown in FIG. As a method for obtaining this characteristic, after assembling the motor parts (after magnetizing the magnetic poles of the stator), a voltage is applied to the DC motor to start it, and a mechanical load is applied to the rotating shaft. There is a method of measuring a motor current value, a rotation speed, and a torque with a current sensor, a rotation sensor, and a torque sensor.

  By the way, the above-described method requires a load applying device (such as an electromagnetic brake) and a torque sensor (torque-voltage converter, etc.) for applying a mechanical load, and the measuring device is complicated and expensive. There is a problem that it ends up. Thus, for example, Patent Document 1 proposes a method for obtaining the above characteristics without requiring such a load applying device or a torque sensor.

  However, in the method of Patent Document 1, the process before assembling the motor parts (before the stator magnetic poles are magnetized) for measuring the restraint current value (restraint current), the no-load current value, and the no-load rotation speed. And a process after assembling the motor parts for measuring the induced voltage and the like (after magnetizing the stator magnetic poles). Further, when re-measurement is performed after the motor parts are assembled, the DC motor needs to be disassembled and reassembled.

Therefore, in Patent Document 2, a motor current value (inrush current value) at the time of starting the motor is measured in order to suppress the increase and complication of the manufacturing process, and the constraint current value is obtained using the peak value of the motor current value. A method for obtaining the value has been proposed. According to the method disclosed in Patent Document 2, the binding current value can be easily obtained even after the motor parts are assembled (after the magnetic poles of the stator are magnetized), and the above-described manufacturing process can be simplified. .
JP-A-9-197027 ([0019], [0020]) Japanese Patent Laid-Open No. 2003-23796

  By the way, depending on the configuration of the winding, commutator, and brush of the DC motor, the winding resistance between the motor electrodes structurally depends on the positional relationship between the commutator and the brush at the motor stop position at the start of measurement (when the motor is started). There will be a difference that cannot be ignored. Therefore, in the method of obtaining the restraint current value using the peak value of the motor current value at the time of startup as in Patent Document 2, the peak value varies due to the difference in winding resistance, and the restraint current based on this The dispersion of values will increase.

  FIG. 4 shows a commutator 91 having twelve segments, four brushes 92 arranged at equiangular (90 °) intervals, and twelve windings (one slot worth) between each adjacent segment. It is explanatory drawing that a difference arises in the coil | winding resistance between motor electrodes by taking as an example the direct-current motor provided with the coil | winding 93) by the positional relationship of the commutator and brush of a motor stop position. That is, FIGS. 4A and 4C are schematic views of the DC motor and the windings between the motor electrodes when the motor stop position is at a position where the brush 92 does not straddle the segment of the adjacent commutator 91 (does not short-circuit). Each line resistance is shown. 4B and 4D are schematic views of the DC motor when the motor stop position is at a position where the brush 92 straddles (short-circuits) the adjacent segment of the commutator 91 and winding resistance between the motor electrodes. Respectively. 4A and 4B, the positive side terminal of the power source connected to the brush 92 is represented as an electrode (+), and similarly, the negative side terminal of the power source connected to the brush 92 is represented as an electrode (−). ). That is, the winding resistance between the motor electrodes corresponds to the winding resistance between these electrodes (+) and (−). 4C and 4D represents the winding resistance for one slot (the resistance of the winding 93).

  As shown in FIGS. 4A and 4B, the adjacent brushes 92 are connected to the power supply with different polarities, and in the same figure, the brushes 92 facing vertically and horizontally are respectively positive side terminals of the power supply. And the negative terminal.

  Here, in the state shown in FIG. 4A, the adjacent brushes 92 are short-circuited via three windings 93. Therefore, the winding resistance between the motor electrodes at this time is a combined resistance in which three resistors R connected in series by three windings 93 are connected in parallel. That is, the resistance between the motor electrodes at this time, that is, the winding resistance between the electrodes (+) and (−) is (3/4) R.

  On the other hand, in the state shown in FIG. 4B, the adjacent brushes 92 are short-circuited via two windings 93. Accordingly, the winding resistance between the motor electrodes at this time is a combined resistance in which two resistors R connected in series by two windings 93 are connected in parallel. That is, the resistance between the motor electrodes at this time, that is, the winding resistance between the electrodes (+) and (−) is (1/2) R.

As described above, the winding resistance between the electrodes (+) and (−) varies in the range from (3/4) R to (1/2) R.
Next, the influence of the difference in winding resistance between the electrodes (+) and (−) on the peak value will be described with reference to FIG. 5 (a) and 5 (b) are graphs showing the transition of the motor current value at the time of starting the motor in the state shown in FIGS. 4 (a) and 4 (b), respectively. As is clear from the figure, the peak value in FIG. 5B corresponding to the state shown in FIG. 4B is the same as that in FIG. 5A corresponding to the state shown in FIG. The value is larger than the peak value, and there is a variation in the difference ΔIp between the two peak values. Therefore, variations also occur in the constraining current values obtained based on the peak values having such variations, and the accuracy is naturally inferior.

  A first object of the present invention is to provide a method for calculating a constraint current of a DC motor that can easily and accurately calculate the constraint current value without being affected by the configuration of the DC motor.

  A second object of the present invention is to provide a DC motor manufacturing method and a DC motor manufacturing apparatus capable of easily and accurately obtaining the characteristics without being influenced by the configuration of the DC motor and manufacturing the DC motor. There is.

  In order to solve the above problems, the invention according to claim 1 is directed to the motor current value during the period from when the motor current value reaches a peak value as the DC motor starts up to when the DC motor rotates normally. The gist is to calculate the binding current value of the DC motor based on a transient current value that is less than the peak value and equal to or more than the current value during steady rotation of the DC motor.

In the invention according to claim 1, the transient current value is a motor current value after a predetermined time from the start of the DC motor, and the transient current value and a predetermined constant obtained in advance. Based on the above, the gist of calculating the binding current value of the DC motor is described.

Further, the invention according to claim 1, before Symbol predetermined time, the same motor current value starts changing the stop position of the DC motor in a DC motor multiple measurements was determined plurality of times motors Each stop position of the DC motor when the motor current value at the time of starting is measured a plurality of times is obtained by rectifying the DC motor at each stop position. The gist is that a difference occurs in the resistance of the motor winding between the motor electrodes due to the positional relationship between the child and the brush .

According to a second aspect of the present invention, in the method for calculating a binding current of a direct current motor according to the first aspect , the predetermined constant is a motor that is a predetermined time after the start of the direct current motor by a plurality of direct current motors of the same type and the same type. The gist is to measure the current value and the restraining current value and obtain them based on the both measured values.

According to a third aspect of the present invention, a voltage is applied to the DC motor after assembling the motor parts to start the DC motor, and the DC motor rotates at a steady state after the motor current value reaches a peak value along with the startup. A rush current measurement step of measuring a transient current value after a predetermined time from the start-up, a transient current value, and a restraint current of the DC motor based on the transient current value and a predetermined constant determined in advance. A restraint current calculation step for calculating a value, a no-load current measurement step for measuring a no-load current value when rotation with no load becomes a steady rotation after the inrush current measurement step, and an inrush current measurement step Then, after the no-load rotation speed measurement step for measuring the no-load rotation speed when the rotation under no load becomes a steady rotation, and after the no-load current measurement step and the no-load rotation speed measurement step, to the DC motor Stop the voltage application and stop Inductive voltage measurement process for measuring the induced voltage at the time, and the restraint torque is calculated based on the restraint current value, the no-load current value, the no-load rotation speed, and the induced voltage, and the characteristics of the DC motor are specified. And a characteristic calculation step.

Further, the invention according to claim 3, the pre-Symbol predetermined time, the same motor current value starts changing the stop position of the DC motor in a DC motor multiple measurements was determined plurality of times motors with obtained based on the time from start of the electric current value difference is negligible, the stop position of the DC motor when multiple measurements of the motor current value during the startup, commutation of the DC motor at each stop position The gist is that a difference occurs in the resistance of the motor winding between the motor electrodes due to the positional relationship between the child and the brush .

According to a fourth aspect of the present invention, in the DC motor manufacturing method according to the third aspect , the predetermined constant is a motor current value after the predetermined time from the start of the DC motor by a plurality of DC motors of the same type and the same type. In addition, the gist is to measure the restraint current value and obtain it based on the both measured values.

According to a fifth aspect of the present invention, a voltage is applied to the DC motor after assembling the motor parts to start the DC motor, and the DC motor rotates at a steady state after the motor current value reaches a peak value with the startup. Inrush current measuring means for measuring a transient current value after a predetermined time from the start-up until the start, a restraint current of the DC motor based on the transient current value and a predetermined constant determined in advance A constraint current calculating means for calculating a value, a no-load current measuring means for measuring a no-load current value when rotation at no load becomes a steady rotation after measuring the transient current value, and the transient After measuring a current value, after measuring the no-load current value and the no-load rotation speed, the no-load rotation speed measuring means for measuring the no-load rotation speed when the rotation under no load becomes a steady rotation Stop applying voltage to the DC motor An induced voltage measuring means for measuring an induced voltage when the motor is stopped; and a constraint torque is calculated based on the constraint current value, the no-load current value, the no-load rotation speed, and the induced voltage, and the characteristics of the DC motor And a characteristic calculating means for specifying

Further, the invention according to claim 5, before Symbol predetermined time, the same motor current value starts changing the stop position of the DC motor in a DC motor multiple measurements was determined plurality of times motors Each stop position of the DC motor when the motor current value at the time of starting is measured a plurality of times is obtained by rectifying the DC motor at each stop position. The gist is that a difference occurs in the resistance of the motor winding between the motor electrodes due to the positional relationship between the child and the brush .

According to a sixth aspect of the present invention, in the DC motor manufacturing apparatus according to the fifth aspect , the predetermined constant is a motor current value after the predetermined time from the start of the DC motor by a plurality of DC motors of the same type and type. In addition, the gist is to measure the restraint current value and obtain it based on the both measured values.

(Function)
According to the first aspect of the present invention, the constrained current value of the DC motor is calculated based on a transient current value in which the motor current value is less than the peak value and is equal to or greater than the current value during steady rotation of the DC motor. The It has been confirmed that this transient current value is less influenced by the motor stop position at the start time due to the configuration of the DC motor than the peak value, for example, and has a correlation with the constraint current value. Therefore, the restraint current value of the direct current motor based on the transient current value is calculated more accurately with the influence of the structure of the direct current motor being suppressed. Needless to say, the binding current value of the DC motor can be easily obtained, for example, after the motor parts are assembled.

Further , based on the transient current value and a predetermined constant obtained in advance, the binding current value of the DC motor can be calculated very simply.
The predetermined time is the same motor current value starts changing the stop position of the DC motor in a DC motor is measured a plurality of times, from the start to the difference between the plurality of times measured motor current value is negligible Since it is obtained based on time, the influence on the transient current value due to the stop position of the DC motor (configuration of the DC motor) is more reliably suppressed. And the restraint current value of the DC motor based on this transient current value can also be obtained with higher reliability.

According to the second aspect of the present invention, the predetermined constant is obtained by measuring the motor current value and the restraining current value after the predetermined time from the start of the DC motor from a plurality of DC motors of the same type and the same type. Since it is obtained based on the value, a highly reliable constant can be easily obtained.

According to the third aspect of the present invention, in the inrush current measuring step, a voltage is applied to the DC motor after the motor parts are assembled to start the DC motor, and the motor current value reaches a peak value with the startup. A transient current value is measured after a predetermined time from the start-up until the DC motor rotates at a steady speed. In the constraint current calculation step, a constraint current value is calculated from the transient current value and a predetermined constant obtained in advance. Then, after the inrush current measurement step, the no-load current value when the no-load rotation becomes the steady rotation is measured in the no-load current measurement step. In addition, after the inrush current measurement step, the no-load rotation number when the no-load rotation becomes a steady rotation is measured in the no-load rotation number measurement step. Then, after the no-load current measurement step and the no-load rotation speed measurement step, in the induced voltage measurement step, the application of voltage to the DC motor is stopped, and the induced voltage at the stop is measured. Then, in the characteristic calculation step, a restriction torque is calculated based on the restriction current value, the no-load current value, the no-load rotation speed, and the induced voltage, and the characteristic of the DC motor is specified. Therefore, load application equipment (electromagnetic brake, etc.) for applying mechanical load and torque sensor (torque-voltage converter, etc.) are not required, and DC motor characteristics can be obtained after motor parts are assembled. Can do. Further, the characteristics of the DC motor can be obtained only by applying and stopping the voltage once to the DC motor after the motor parts are assembled. Thus, with this method, the characteristics of the DC motor can be easily obtained at low cost, and as a result, the DC motor can be easily manufactured at low cost.

  In particular, the transient current value used for calculation of the constraint current value in the constraint current calculation step is less affected by the motor stop position at startup due to the configuration of the DC motor than the peak value, for example. Therefore, the restraint current value of the DC motor based on the transient current value is calculated more accurately with the influence of the configuration of the DC motor being suppressed. As a result, the restricting torque calculated based on the restricting current value and the like in the characteristic calculating step can be calculated more accurately, and the characteristics of the DC motor can be obtained more accurately.

In addition , the predetermined time is determined by measuring the motor current value at the start-up several times by changing the stop position of the DC motor in the same DC motor, and starting from the start-up where the difference between the motor current values measured a plurality of times can be ignored. Since it is obtained based on time, the influence on the transient current value due to the stop position of the DC motor (configuration of the DC motor) is more reliably suppressed. And the restraint current value of the DC motor based on this transient current value can also be obtained with higher reliability.

According to a fourth aspect of the present invention, the predetermined constant is obtained by measuring a motor current value and a restraining current value after the predetermined time from the start of the DC motor by using a plurality of DC motors of the same type and the same type. Since it is obtained based on the value, a highly reliable constant can be easily obtained.

According to the fifth aspect of the present invention, the inrush current measuring means applies a voltage to the DC motor after assembling the motor parts to start the DC motor, and the motor current value reaches a peak value along with the startup. A transient current value is measured after a predetermined time from the start-up until the DC motor rotates at a steady speed. Then, the restraining current calculation means calculates the restraining current value from the transient current value and a predetermined constant obtained in advance. Then, after the transient current value is measured, the no-load current measuring means measures the no-load current value when the no-load rotation becomes the steady rotation. In addition, after the transient current value is measured, the no-load rotation speed measurement means measures the no-load rotation speed when the no-load rotation becomes the steady rotation. Then, after the no-load current value and the no-load rotation speed are measured, application of voltage to the DC motor is stopped by the induced voltage measuring means, and the induced voltage at the time of the stop is measured. Then, the characteristic calculation means calculates the restriction torque based on the restriction current value, the no-load current value, the no-load rotation speed, and the induced voltage, and specifies the characteristics of the DC motor. Therefore, load application equipment (electromagnetic brake, etc.) for applying mechanical load and torque sensor (torque-voltage converter, etc.) are not required, and DC motor characteristics can be obtained after motor parts are assembled. Can do. In addition, after the motor parts are assembled, it is possible to obtain the characteristics of the DC motor by simply applying and stopping the voltage once to the DC motor. Thereby, in this apparatus, the characteristics of the DC motor can be easily obtained at low cost, and as a result, the DC motor can be easily manufactured at low cost.

  In particular, the transient current value used for calculation of the constraint current value by the constraint current calculation means is less susceptible to the influence of the motor stop position at startup due to the configuration of the DC motor, for example, than the peak value. Therefore, the restraint current value of the DC motor based on the transient current value is calculated more accurately with the influence of the configuration of the DC motor being suppressed. As a result, the restricting torque calculated based on the restricting current value and the like by the characteristic calculating means is more accurately calculated, and the characteristic of the DC motor can be obtained more accurately.

In addition , the predetermined time is determined by measuring the motor current value at the start-up several times by changing the stop position of the DC motor in the same DC motor, and starting from the start-up where the difference between the motor current values measured a plurality of times can be ignored. Since it is obtained based on time, the influence on the transient current value due to the stop position of the DC motor (configuration of the DC motor) is more reliably suppressed. And the restraint current value of the DC motor based on this transient current value can also be obtained with higher reliability.

According to the invention described in claim 6 , the predetermined constant is obtained by measuring the motor current value and the restraining current value after the predetermined time from the start of the DC motor from a plurality of DC motors of the same type and the same type. Since it is obtained based on the value, a highly reliable constant can be easily obtained.

As described above in detail, according to the first and second aspects of the present invention, the restraining current value can be easily and accurately calculated without being affected by the configuration of the DC motor.
According to the third to sixth aspects of the present invention, the DC motor can be manufactured by easily and accurately obtaining the characteristics without being influenced by the configuration of the DC motor.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. As shown in FIG. 1, a DC motor manufacturing apparatus for characteristic measurement includes a current sensor (ammeter) 1, a personal computer (hereinafter referred to as a personal computer) 2, a power source 3, and a switch 4. The personal computer 2 includes a current measurement unit 5, a calculation unit 6, a voltage measurement unit 7, and an output unit 8.

  In the present embodiment, the current sensor 1, the personal computer 2 (specifically, the current measuring unit 5 and the calculating unit 6) and the switch 4 constitute inrush current measuring means. Further, the current sensor 1 and the personal computer 2 (specifically, the current measurement unit 5 and the calculation unit 6) constitute a no-load current measurement unit and a no-load rotation number measurement unit. Further, the personal computer 2 (specifically, the calculation unit 6) constitutes a constraint current calculation unit and a characteristic calculation unit. The personal computer 2 (specifically, the calculation unit 6 and the voltage measurement unit 7) and the switch 4 constitute an induced voltage measurement unit.

  The power supply 3 has a negative terminal connected to the first terminal 11 via the current sensor 1, and a positive terminal connected to the second terminal 12 via the switch 4. The current sensor 1 is connected to the personal computer 2 (current measurement unit 5). Furthermore, the first and second terminals 11 and 12 are connected to the personal computer 2 (voltage measuring unit 7), respectively.

The current sensor 1 outputs an analog signal (voltage signal) S1 corresponding to the current value to the personal computer 2 (current measurement unit 5).
The personal computer 2 performs various processes by a predetermined operation.

In the personal computer 2, the current measuring unit 5 converts the signal S <b> 1 into a digital current value signal S <b> 2 and outputs this to the computing unit 6.
In the personal computer 2, the voltage measurement unit 7 converts the voltage signal between the first and second terminals 11 and 12 into a digital voltage value signal S 3 and outputs the digital voltage value signal S 3 to the calculation unit 6.

  In the personal computer 2, the calculation unit 6 has predetermined constants α and β input in advance, performs various calculations, and outputs the calculation results to the output unit 8. In addition, about the calculation of the said calculating part 6, it explains in full detail by the manufacturing method of the DC motor which concerns on the below-mentioned characteristic measurement, and detailed description here is abbreviate | omitted.

In the personal computer 2, the output unit 8 is connected to an external monitor (not shown) and displays the calculation result on the monitor.
Next, a DC motor manufacturing method performed by the DC motor manufacturing apparatus configured as described above will be described.

  In the present embodiment, the motor current value is less than the peak value and the current value at the time of steady rotation of the DC motor during the period from when the motor current value reaches the peak value with the start of the DC motor until the DC motor rotates normally. Based on the above transient current value (hereinafter, referred to as “rush current transient value It”), the restraint current value Is of the DC motor is calculated. That is, based on the motor current value (inrush current transient value It) after a predetermined time to from the start of the DC motor, the binding current value Is of the DC motor is calculated. This is because the inrush current transient value It is caused by the configuration of the DC motor (configuration of winding, commutator, and brush) compared to the peak value of the motor current value described in the conventional example (Patent Document 2). This is because it is less affected by the motor stop position and has a correlation with the constraint current value Is.

  Here, taking the above-described DC motor shown in FIG. 4 as an example, it will be described based on FIG. 2 that the inrush current transient value It is not easily influenced by the configuration of the DC motor. FIG. 2 (a) (b ) Is a graph showing the transition of the motor current value at the time of starting the motor in the state shown in FIGS. As is apparent from FIG. 4, the inrush current transient value It in FIGS. 2A and 2B corresponding to the states shown in FIGS. 4A and 4B is independent of the aforementioned variation in peak value. The variation is suppressed and the values are equivalent.

  That is, when the motor current value exceeds the peak value and the DC motor starts to rotate, the motor current value decreases and becomes a substantially constant motor current value regardless of the motor stop position before starting after a predetermined time to. . This is because the winding resistance between the motor electrodes and the winding resistance between the electrodes at all motor stop positions are average values if the DC motor is rotating, and converges to a constant value if the motor is the same.

  Therefore, by measuring the inrush current transient value It and obtaining the constraint current value Is having a correlation therewith, a more accurate constraint current value in which the influence of the configuration of the DC motor is suppressed can be obtained. Since the inrush current transient value It is a current value during motor rotation, the value is affected by the magnetic circuit and mechanical loss of the DC motor. However, since these influences are sufficiently smaller than changes in the winding resistance between the motor electrodes due to the motor stop position, the constraint current value can be obtained with higher accuracy by using the inrush current transient value It.

  First, the acquisition mode of the predetermined time to related to the measurement of the inrush current transient value It will be described. In the present embodiment, in the same completed DC motor (characteristic is determined to satisfy the demand of the user or the like), the motor current value at the start is measured a plurality of times by changing the stop position of the DC motor, and the plurality of times The predetermined time to is determined on the basis of the time from start-up in which the difference between the measured motor current values can be ignored. The state where the difference between the motor current values can be ignored refers to a state where the difference between the motor current values measured a plurality of times is below a predetermined value. For example, in a DC motor having a rated torque of 1.18 [N · m], the motor current value can be reduced in the shortest time by setting the predetermined time to in the range of 2 to 200 [ms (milliseconds)]. It has been confirmed that the difference becomes negligible. In addition, it has been confirmed that this DC motor rotates normally in about 1 second from startup.

  When the predetermined time to is acquired, the inrush current transient value It and the restraint current value are measured from 30 completed DC motors of the same type and the same type that have been determined in advance (characteristics are determined to meet the user's demand). Then, the predetermined constants α and β are acquired based on these measured values. These constants α and β are constants for calculating the constraint current value Is from the inrush current transient value It (so-called regression analysis), and are calculated so as to satisfy the following expression (A). .

Is = α × It + β (A) Equation The constraint current value measured when obtaining the predetermined constants α and β also varies depending on the motor stop position. Therefore, the restraint current value at this time is measured a plurality of times by changing the stop position of the DC motor, and the restraint current value for obtaining the correlation between the representative value of the restraint current value measured several times and the inrush current transient value. And For example, an average value, a maximum value, or a minimum value of the restricted current values measured a plurality of times may be adopted as the representative value of the restricted current value.

  When measuring the characteristics, first, as shown in FIG. 1, the power input terminal of the DC motor M is connected to the first and second terminals 11 and 12. The direct current motor M described here is one in which motor parts are assembled (the magnetic poles of the stator are magnetized), and the characteristics thereof are not measured. The DC motor M here has, for example, the structure shown in FIG. 4 where the rated torque is 1.18 [N · m], and the predetermined time to is set to 20 [ms] correspondingly. Has been. Needless to say, the adjacent brushes 92 (see FIG. 4) of the DC motor M connected to the first and second terminals 11 and 12 are connected to the power supply 3 with different polarities via the switch 4. Absent.

  Next, a manufacturing method related to the characteristic measurement of the DC motor M will be described on the assumption that the above preparation steps have been completed. The manufacturing method in the present embodiment includes an “inrush current measurement step”, a “constrained current calculation step”, a “no-load current measurement step”, a “no-load rotation speed measurement step”, an “induced voltage measurement step”, and “ These steps are described below step by step.

"Inrush current measurement process"
First, in the “rush current measurement process”, the voltage of the power source 3 is applied to the DC motor M by the current sensor 1, the personal computer 2 (specifically, the current measurement unit 5 and the calculation unit 6) and the switch 4 to start it up. Then, the inrush current transient value It is measured.

  Specifically, the switch 4 is turned on, and the DC motor M is started with no load. Then, as shown in FIG. 2, the calculation unit 6 is a motor current value after a predetermined time to start from the start by the motor current value (current value signal S2) input via the current sensor 1 and the current measurement unit 5. The inrush current transient value It is measured. For example, when the operation of the switch 4 is performed by the processing of the personal computer 2, the elapsed time since the start is obtained by measuring the elapsed time after the processing by the calculation unit 6. Alternatively, the elapsed time from the start-up is obtained by measuring the elapsed time after the change of the motor current value with the start-up of the DC motor M by the calculation unit 6. Then, the motor current value (current value signal S2) when the elapsed time from the start coincides with the predetermined time to is measured as the inrush current transient value It.

"Restrained current calculation process"
Next, in the “restraint current calculation step”, the operation unit 6 calculates the restraint current value Is from the inrush current transient value It and the predetermined constants α and β.

Specifically, the calculation unit 6 calculates the constraint current value Is by solving the equation (A) using the measured inrush current transient value It and predetermined constants α and β.
"No-load current measurement process"
Next, in the “no-load current measurement process”, the current sensor 1 and the personal computer 2 (specifically, the current measurement unit 5 and the calculation unit 6) stably rotate the DC motor M with no load in a steady state. Measure the no-load current value (current value during steady rotation) Io.

Specifically, the calculation unit 6 measures the current value when the motor current value (current value signal S2) input via the current sensor 1 and the current measurement unit 5 is stabilized as the no-load current value Io.
"No-load rotational speed measurement process"
Next, in the “no-load rotation speed measurement process”, the current sensor 1 and the personal computer 2 (specifically, the current measurement unit 5 and the calculation unit 6) stably rotate the DC motor M without load. Measure the no-load rotational speed No.

  Specifically, the calculation unit 6 calculates the no-load rotation speed No from the current pulsation component of the no-load current value Io. Here, since the current pulsation component is generated corresponding to the number of slots of the armature core of the DC motor M, no load is obtained by dividing (dividing) the number of current pulsations per unit time by the number of slots. The rotation speed No is calculated.

`` Inductive voltage measurement process ''
Next, in the “induced voltage measurement process”, the application of voltage to the DC motor M is stopped by the personal computer 2 (specifically, the calculation unit 6 and the voltage measurement unit 7) and the switch 4, and the induced voltage at the time of the stop. Measure Eo.

  Specifically, the switch 4 is turned off and the application of the voltage to the DC motor M is stopped. And the induced voltage Eo is measured in the calculating part 6 from the voltage value (voltage value signal S3) input via the voltage measurement part 7 at that time.

"Characteristic calculation process"
Next, in the “characteristic calculation step”, the calculation unit 6 calculates the constraint torque Ts based on the constraint current value Is, the no-load current value Io, the no-load rotation speed No, and the induced voltage Eo, The characteristics (see FIG. 3) of the DC motor M are specified.

  Specifically, the calculation unit 6 calculates the no-load angular speed ωo from the no-load rotational speed No and the following equation (B), and the induced voltage constant from the angular velocity ωo, the induced voltage Eo, and the following equation (C). Ek is calculated to specify the characteristics (see FIG. 3).

ωo = 2π × No / 60 (rad / sec) (B) equation Ek = ωo / Eo (C) equation Here, the induced voltage constant Ek is the slope in the motor current value-torque characteristic in the characteristic diagram shown in FIG. Since the no-load current value Io and the restraint current value Is have already been obtained, the motor current value-torque characteristic is specified. Since the torque at the restricted current value Is is the restricted torque Ts, the restricted torque Ts can be obtained from the motor current value-torque characteristic. That is, the calculation unit 6 calculates the constraint torque Ts from the constraint current value Is, the no-load current value Io, the induced voltage constant Ek, and the following equation (D).

Ts = (Is−Io) / Ek (D) Formula Also, as shown in FIG. 3, since the no-load rotational speed No is already obtained, the rotational speed-torque characteristic is specified. Therefore, the characteristics (see FIG. 3) of the DC motor M are specified.

Next, the output unit 8 outputs the calculation result, that is, the data of the rotation speed / motor current value-torque characteristics (see FIG. 3) to an external monitor (not shown), and displays the characteristics on the monitor.
Therefore, it is possible to specify torque (such as rated torque) in an arbitrary state by the above characteristics (see FIG. 3). Then, it is determined whether or not the characteristics and the values (rated torque, etc.) obtained from the characteristics satisfy the user's demand, and the products determined to satisfy the demand are defined as products.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the restraint current value Is of the DC motor M is calculated from the inrush current transient value It of the DC motor M and predetermined constants α and β obtained in advance, and the rotational speed and motor current value thereof are calculated. -Specified torque characteristics. Therefore, it does not require a load application device (such as an electromagnetic brake) or a torque sensor (torque-voltage converter, etc.) for applying a mechanical load, and after assembling the motor parts (after magnetizing the stator magnetic poles) ), The characteristics of the DC motor M can be obtained by concentrated measurement and calculation.

  Moreover, after the motor parts are assembled (after the magnetic poles of the stator are magnetized), the characteristics of the DC motor M can be obtained efficiently and in a short time simply by applying and stopping the voltage once to the DC motor M. Is possible. Thereby, in this apparatus and method, the characteristics of the DC motor M can be easily obtained at low cost, and as a result, the DC motor M can be easily manufactured (commercialized) at low cost. Alternatively, when performing re-measurement of characteristics, it is possible to easily obtain characteristics at low cost without the need for disassembly / reassembly.

  In particular, the inrush current transient value It used for the calculation of the restraint current value Is is less affected by the motor stop position at the start-up due to the configuration of the DC motor M than the peak value of the conventional example, for example. The restraining current value Is of the DC motor M based on the inrush current transient value It can be calculated more accurately because the influence of the configuration of the DC motor is suppressed. As a result, the restraining torque Ts calculated based on the restraining current value Is or the like can be calculated more accurately, and the characteristics of the DC motor M can be obtained more accurately.

  (2) In the present embodiment, during the predetermined time to, the stop position is changed in the same DC motor, the motor current value at the start is measured a plurality of times, and the difference between the motor current values measured a plurality of times is ignored. Since it is obtained based on the time from the start that can be performed, the influence on the inrush current transient value It caused by the stop position of the DC motor (configuration of the DC motor) can be more reliably suppressed. Further, the constraining current value Is of the DC motor based on the inrush current transient value It is also obtained with higher reliability.

  (3) In the present embodiment, the predetermined constants α and β are determined from the motor current value (inrush current transient value) and the restraint current after the predetermined time to from the start of the DC motor by 30 DC motors of the same type and type. Since a value is measured and obtained based on both of these measured values, a highly reliable constant can be easily obtained, and as a result, a highly reliable binding current value Is can be calculated.

  (4) In this embodiment, the no-load rotation speed No is calculated from the current pulsation component of the no-load current value Io, so there is no need to provide a dedicated rotation sensor or the like as a separate part, and the DC can be reduced at a lower cost. The characteristics of the motor M can be obtained.

In addition, you may change the said embodiment as follows.
In the above-described embodiment, the DC motor manufacturing apparatus and the manufacturing method have been described. However, if there is a demand to acquire (re-acquire) the binding current value Is of the DC motor after the motor parts are assembled, the above process Only a part (“inrush current measurement process” and “restraint current calculation process”) may be performed. Even in this case, the restraining current value can be calculated more accurately without being affected by the configuration of the DC motor. Needless to say, the restraint current value of this DC motor is, for example, a load applying device (such as an electromagnetic brake) for mechanically applying a load after assembly of the motor parts, a torque sensor (torque-voltage converter, etc.) ) Is not required, and disassembly / reassembly is not required.

  The DC motor manufacturing apparatus of the above embodiment has similar functions (inrush current measuring means, restraint current calculating means, no-load current measuring means, no-load rotational speed measuring means, induced voltage measuring means, and characteristic calculating means). If it exists, you may comprise with another apparatus. For example, a microcontroller (hereinafter referred to as “microcomputer”) may be employed instead of the personal computer 2. If the microcomputer does not include the current measuring unit 5 and the voltage measuring unit 7, an A / D converter or the like may be separately connected to the microcomputer to configure a similar DC motor manufacturing apparatus.

  -In the said embodiment, what is necessary is just to judge based on the elapsed time (for example, 1 second) from the starting time in which steady rotation of the DC motor M is confirmed beforehand that it is in steady rotation. Alternatively, the steady rotation of the DC motor M may be determined based on the fact that the change in the rotational speed within a predetermined time at the start-up falls within a predetermined value.

  In the above embodiment, the predetermined time to is acquired as the time from start-up in which the difference in motor current values measured multiple times in the same DC motor is negligible, but is determined to be the shortest time among them. Is preferred.

  In the embodiment, the inrush current transient value It and the restraint current value Is are measured in advance from 30 completed DC motors of the same type and the same type as the DC motor M, and predetermined constants α and β are determined based on the measured values. However, the method for obtaining the predetermined constants α and β may be changed. For example, the number of DC motors to be measured in advance may be changed to other than 30, for example, 40 or 50. Further, for example, predetermined constants α and β corresponding to the DC motor M of the present embodiment may be obtained by regression analysis from predetermined constants of various types (such as different sizes) of DC motors. .

  In the embodiment, the regression analysis is performed by linear approximation (Equation (A)). However, for example, regression analysis by curve approximation such as polynomial approximation, triangular approximation, exponential approximation, power approximation, logarithmic approximation, or the like may be used.

  In the embodiment, the no-load rotation speed No is calculated from the current pulsation component of the no-load current value Io. However, the no-load rotation speed No may be obtained by another method. For example, the no-load rotation speed No may be measured by a dedicated rotation sensor that is a separate component. Even if it does in this way, the effect similar to the effect of (1)-(3) of the said embodiment can be acquired.

  In the above-described embodiment, the output unit 8 is connected to an external monitor (not shown) and displays the characteristic as a calculation result on the monitor. However, the output unit 8 transmits information based on the calculation result to an information transmission unit other than the monitor. It may be. For example, a pass / fail judgment lamp is connected to the output unit 8. And the calculating part 6 judges whether the said characteristic satisfy | fills the user's demand set beforehand. And the output part 8 transmits the determination result which is a calculation result of the calculating part 6 to the exterior by lighting a pass / fail determination lamp. When the pass / fail is displayed by the pass / fail determination lamp as described above, it is easy for the operator to determine pass / fail, and the production efficiency of the DC motor in a factory or the like can be further improved.

The block diagram which shows one Embodiment of this invention. (A) (b) is a graph which shows transition of the motor current value at the time of motor starting. DC motor rotation speed / motor current value-torque characteristics diagram. (A) (b) (c) (d) is explanatory drawing which shows the relationship between a motor stop position and winding resistance. (A) (b) is a graph which shows transition of the motor current value at the time of motor starting.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Current sensor, 2 ... Personal computer, 4 ... Switch, 5 ... Current measurement part, 6 ... Calculation part, 7 ... Voltage measurement part.

Claims (6)

The motor current value is less than the peak value and greater than or equal to the current value at the time of steady rotation of the DC motor during the period from when the motor current value reaches the peak value with the start of the DC motor until the DC motor rotates normally. A DC motor restraint current calculation method for calculating a DC motor restraint current value based on a transient current value of :
The transient current value is a motor current value after a predetermined time from the start of the DC motor, and the predetermined time is a motor current value at the time of starting by changing the stop position of the DC motor in the same DC motor. Are measured based on the time from start-up when the difference between the motor current values measured multiple times is negligible, and each stop of the DC motor when measuring the motor current value at the start-up multiple times The position is a position where a difference occurs in the resistance of the motor winding between the motor electrodes due to the positional relationship between the commutator and the brush of the DC motor at each stop position,
A method for calculating a constraint current of a DC motor, wherein the constraint current value of the DC motor is calculated based on the transient current value and a predetermined constant obtained in advance . In the direct current motor restraint current calculation method according to claim 1,
The predetermined constant is obtained from a plurality of DC motors of the same type and the same type by measuring a motor current value and a restraining current value after the predetermined time from the start-up of the DC motor, and obtaining the predetermined constant based on the measured values. A method for calculating the motor restraint current. Starting the DC motor by applying a voltage to the DC motor after assembling the motor parts, from the start of the motor until the DC motor rotates normally after the motor current value reaches its peak value. Inrush current measurement process for measuring a transient current value after a predetermined time;
A restraint current calculation step of calculating a restraint current value of the DC motor based on the transient current value and a predetermined constant obtained in advance;
After the inrush current measurement step, a no-load current measurement step for measuring a no-load current value when rotation with no load becomes a steady rotation,
After the inrush current measurement step, a no-load rotation number measurement step for measuring the no-load rotation number when the rotation without load becomes a steady rotation,
After the no-load current measurement step and the no-load rotation speed measurement step, the induced voltage measurement step of stopping the application of voltage to the DC motor and measuring the induced voltage at the stop,
A characteristic calculation step of calculating a binding torque based on the binding current value, the no-load current value, the no-load rotation speed, and the induced voltage, and specifying the characteristics of the DC motor;
A method of manufacturing a direct current motor comprising:
The predetermined time is the time from start-up in which the motor current value at start-up is measured a plurality of times by changing the stop position of the DC motor in the same DC motor, and the difference between the motor current values measured a plurality of times is negligible. And each stop position of the DC motor when the motor current value at the time of starting is measured a plurality of times is determined between the motor electrodes according to the positional relationship between the commutator and the brush of the DC motor at each stop position. A method of manufacturing a DC motor, characterized in that a difference occurs in resistance of a motor winding. In the manufacturing method of the direct-current motor of Claim 3,
The predetermined constant is obtained from a plurality of DC motors of the same type and the same type by measuring a motor current value and a restraining current value after the predetermined time from the start-up of the DC motor, and obtaining the predetermined constant based on the measured values. A method for manufacturing a motor. Starting the DC motor by applying a voltage to the DC motor after assembling the motor parts, from the start of the motor until the DC motor rotates normally after the motor current value reaches its peak value. Inrush current measuring means for measuring a transient current value after a predetermined time;
A restraint current calculation means for calculating a restraint current value of the DC motor based on the transient current value and a predetermined constant obtained in advance;
After measuring the transient current value, no-load current measuring means for measuring the no-load current value when the rotation under no load becomes a steady rotation,
After measuring the transient current value, no-load rotation speed measuring means for measuring the no-load rotation speed when the rotation with no load becomes a steady rotation,
After measuring the no-load current value and the no-load rotational speed, induced voltage measuring means for stopping the application of voltage to the DC motor and measuring the induced voltage at the time of the stop,
A characteristic calculation means for calculating a restriction torque based on the restriction current value, the no-load current value, the no-load rotation speed, and the induced voltage, and specifying a characteristic of the DC motor;
A direct current motor manufacturing apparatus comprising:
The predetermined time is the time from start-up in which the motor current value at start-up is measured a plurality of times by changing the stop position of the DC motor in the same DC motor, and the difference between the motor current values measured a plurality of times is negligible. And each stop position of the DC motor when the motor current value at the time of starting is measured a plurality of times is determined between the motor electrodes according to the positional relationship between the commutator and the brush of the DC motor at each stop position. An apparatus for manufacturing a direct current motor, characterized in that a difference occurs in resistance of a motor winding. In the DC motor manufacturing apparatus according to claim 5,
The predetermined constant is obtained from a plurality of DC motors of the same type and the same type by measuring a motor current value and a restraining current value after the predetermined time from the start-up of the DC motor, and obtaining the predetermined constant based on the measured values. Motor manufacturing equipment.

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