JPH08255B2 - Bending correction method for parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention <Field of Industrial Application> The present invention relates to a method for correcting bending of a member.

<Prior Art> For example, in a power window motor for an automobile, a worm formed at a driving end portion of a rotor shaft and a worm wheel integrally formed with an output shaft connected to open and close the window are meshed with each other. As a result, a small motor may obtain a large output to open and close the window. In this worm gear coupling, in order to perform stable and efficient gear transmission, it is necessary to use a worm with as little bending as possible, that is, center deviation. Therefore, after forming the worm on the rotor shaft, the core runout of the worm is measured by the core runout measuring device, and if the measured value is outside the allowable value, the worm is corrected.

For example, as shown in Japanese Patent Application No. 1-72451 by the same applicant, a member is corrected based on a correction table that gives a correction amount according to the amount of runout, and a single correction allows an allowable value. In some cases, if the amount does not fall within the range, the amount of runout after straightening is measured and straightening is performed again according to the measured value. However, for example, if the production lot is changed, the material and shape of the rotor shaft and the processing state during rolling may differ, and the characteristics such as the hardness of the shaft change from lot to lot. There is a possibility that the same correction effect may not be obtained even in the next lot with the corrected amount. It is conceivable that the operator may change the correction amount on the table again each time the lot is changed, for example, by resetting the coefficient, but this causes a problem that the runout correction work becomes complicated.

<Problems to be Solved by the Invention> In view of the problems of the conventional technology as described above, a main object of the present invention is to improve so that a difference in correction value caused by changing a production lot can be automatically corrected. The present invention provides a method for straightening a curved member.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, such an object is corrected by deforming a member bent in one direction in a direction opposite to the bending direction. A method for correcting the bending of a member of the type, a step of measuring the bending amount of the member, a step of correcting the member based on a correction amount table that gives a correction amount according to a plurality of specific bending amount ranges, A step of measuring the amount of bending of the member after straightening and comparing it with an allowable value, and if the amount of bending of the member after straightening is outside the allowable value, the amount of straightening corresponding to the amount of straightening in the straightening process The table portion is gradually reduced in accordance with the increase in the number of corrections and is corrected by adding a feedback value which becomes a predetermined value, and when the amount of bending after the correction is outside the allowable value, the member after the correction is corrected. Determine bend direction Then, the additional correction amount based on the additional correction amount table that gives the additional correction amount according to the plurality of specific bending amount ranges after the correction is set to a positive value in the case of the same direction as the bending direction before the correction and the opposite directions. In the case of, a process of adding the corrected value as a negative value and making it the data of the portion of the correction amount table after that is provided. To be achieved.

<Operation> In this way, when the production lot is changed, the material and shape of the member and the processing state at the time of rolling are different, and the correct correction is performed with the optimum correction amount in the previous lot. Even if it is difficult, the correction amount table corresponds to the correction amount at the time of re-correction based on the correction amount table, with the additional bending amount according to the bending direction and bending amount of the member after correction. Since the part is corrected, an appropriate correction can be automatically performed when correcting the data for the specific bending amount range corrected in the part having different characteristics in the new lot.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram schematically showing an outline of an apparatus 2 for correcting core runout of a rotor shaft 1 to which the present invention is applied. For example, a worm wheel 1a is formed in the output end portion on the right side of the rotor shaft 1 used in an automobile power window motor in the figure, and a worm wheel in a gear box integrally assembled with the power window motor. And the worm 1a mesh with each other. If the worm 1a is bent, that is, if the center runout occurs, stable and efficient gear transmission cannot be performed. Therefore, in the motor manufacturing process, after the worm 1a is formed on the rotor shaft 1, the center runout correction device 2 is used. The runout is measured, and if it is out of the allowable value, it is corrected.

The center runout correction device 2 is provided with a displacement sensor 3 for measuring the runout of the worm 1a, and a pulse motor 4 with a lead screw as an actuator for correcting the runout. The displacement sensor 3 is composed of, for example, a direct-acting type displacement sensor, is reciprocally movable, and has a push rod 3a adapted to elastically strike the outer peripheral surface of the rotor shaft 1 and a protrusion of the push rod 3a. It has an abutment piece 3b swingably provided at the end, and it is spread over a plurality of teeth so as not to be affected by the missing teeth of the worm 1a.
By bringing the contact piece 3b into contact with the outer peripheral surface of the worm 1a, the runout of the worm 1a is measured, and the measured value is output to the control device 5. Further, the pulse motor 4 has a drive shaft.
When the tip end of the rotor shaft 1 on the worm 1a side is pushed down by the protruding end of 4a in the direction of arrow A in the figure, which is the direction for correcting the bending of the worm 1a, the correction signal described below is generated by the drive signal from the control device 5. It is designed to rotate by the number of pulses according to the value.

Next, the operation procedure of the core shake correction device 2 thus configured will be described below with reference to the flowchart shown in FIG.

First, in step ST1, the contact piece 3b of the displacement sensor 3 is attached to the rotor shaft 1 which is gripped by a chuck (not shown) and is in a fixed state as described above.
The rotor shaft 1 is rotated once around the true axis by rotating the chuck, for example, while elastically contacting the outer peripheral surface of the worm 1a, and the runout of the worm 1a is measured. At this time, the measured value of half the swing width in the vertical direction of the worm 1a rotated once is stored as the position of the true shaft center so that the displacement sensor 3 is moved from the position of the true shaft center in the figure.
By subtracting the displacement amount measured by, the center runout amount Y in which the upper side of the true axis has a positive value and the lower side has a negative value can be calculated. Furthermore, the rotor shaft 1
Rotate and position at the position where the positive value of runout becomes maximum.

Next, in step ST2, the preset allowable value is compared with the core runout amount measured in step ST1, and if the core runout amount is within the allowable value, the process ends without correction, and If the amount of runout is outside the allowable value, the process proceeds to step ST3, and the runout is corrected in step ST3. When correcting this runout, in order to push the drive shaft 4a and push down the tip end portion of the rotor shaft 1 as described above, the pulse motor 4 is adjusted to a correction amount in a memory unit 6 described later. Rotate only the pulse corresponding to the data Z. The correction amount data Z is read from a so-called data table preset as a correction amount table given according to a plurality of specific center deviation amounts. Then, in step ST4, the amount of runout after straightening is measured, and the next step ST5
At this point, the allowable value is again compared with the amount of runout measured in step ST4, and if the amount of runout is within the allowed value, correction is not performed and the process ends.

In step ST5, when the center runout amount is out of the allowable value, the process proceeds to step ST6. The reason why the process proceeds to step ST6 is that the correction based on the stocked correction amount data Z was insufficient. Therefore, in step ST6, the feedback value for correcting the correction amount data Z is used. Xn is calculated by the following formula.

Xn = A · Y / (n + 3) A in the above formula is the number of pulses per unit runout amount for rotating the pulse motor 4, and n is the step ST.
This value is incremented (the number of rotor shafts for which the same amount of runout has been measured) when there is one that has not been sufficiently corrected in Step 3 and has proceeded to Step ST6. Step ST
At 1, for example, a certain amount of runout (Y = Y1) is measured for the first time,
The correction based on the correction amount data corresponding to the center runout amount Y1 is performed in step ST3, and if the process does not fall within the allowable value and proceeds to step ST6, the correction formula in the correction formula corresponding to the above center runout amount Y1 Let n be 1. Then, similarly for other rotor shafts, different core run-out amounts Y2, Y3, ... When the process proceeds to step ST6, similarly, then step ST1
When the center runout amount Y1 is measured at step ST6 and the process proceeds to step ST6, the number of corrections to the center runout amount Y1 becomes the second time, and n when performing the correction by the above equation is set to 2. Therefore, when the process proceeds to step ST6 for the first time, n of the correction equation corresponding to the table portion of the amount of center deviation (eg, Y1) measured at step ST1 at that time becomes 1 to obtain the feedback value X _n . The denominator of the above equation is 4, and as the number of steps that go to step ST6 at the same center runout amount (Y1) increases, n in the correction equation increases by one, so the value of Xn gradually converges. . It should be noted that the upper limit of n may be set to about 15, for example.

Further, in the control device 5, the correction amount data Z is calculated by the following equation.

Z = A · Y + ΣXn That is, the number of pulses for rotating the pulse motor 4 proportional to the center runout amount Y is calculated by the first term on the right side of the above equation, and the cumulative feedback value Xn is calculated by the second term. The value is calculated, and the correction amount data Z is calculated by the sum of the two. Incidentally, the correction amount data Z is stocked in the data table divided into a plurality of specific runout amount ranges as described above, and when the feedback value Xn is calculated in step ST6, the lead based The correction amount data Z stored in the shake amount Y section is rewritten.

Step ST in the next new rotor shaft 1 straightening process
When the center runout amount Y that is the same as the runout in which the correction amount data Z is corrected in 1 is measured, the correction amount data Z applied to the measured value is the feedback value Xn more than the previous value. It is increased by the amount, and a larger correction can be performed. However, if the correction amount data Z is still insufficient, the process proceeds to step ST6, and the correction amount data Z is corrected again.
The feedback value Xn included in the correction amount data Z
However, as described above, it decreases as the number of times the same center runout amount Y is measured and corrected increases, and since it becomes a predetermined value by setting the upper limit of n, the correction amount data Z also converges, It is possible to preferably prevent the inconvenience that the correction width of the correction amount data Z is too large.
The data Z of an appropriate correction amount can be automatically obtained.

After the feedback value Xn is calculated in step ST6 as described above, the process proceeds to step ST7. In step ST7, in order to determine the characteristics of the runout when the value does not fall within the allowable value, the direction of the runout and the amount of runout are calculated. In determining the direction of the runout, whether the rotor shaft 1 is relatively hard and remains bent in the same direction as the bending direction before the correction even after the correction.
Is relatively soft and is bent in the opposite direction beyond the position of the true axis described above. Further, in the calculation of the amount of runout, the amount of runout Y measured in step ST4 can be used. Based on this characteristic judgment, the additional correction amount is read by using, for example, the additional correction amount table including a data table similar to the above-mentioned correction amount table.
At this time, when it is determined that the runout direction is the same as the bending direction before correction, the additional correction amount read from the additional correction amount table is set to a positive value, and when it is determined that the opposite direction is detected. The additional correction amount is added as a negative value to the correction amount data Z.

After step ST7, the process proceeds to step ST8 and step ST
In step 8, if it is detected in step ST5 that the test has failed a predetermined number of times (N times), the process proceeds to step ST9 to display the fail and terminate. It should be noted that the number of confirmations in step ST8 is appropriately two, for example, when a motor is produced on an automatic production line. If the rejection is less than N times, the process returns to step ST3 and is corrected again. Further, in the case where the amount of runout corresponds to the corrected table data in the other member, the pulse motor 4 is moved by a corresponding number of pulses according to the correction amount to which the additional correction amount is added as described above. Rotate and straighten again. Therefore, for example, even if the production lot is changed and overcorrection or excessive correction insufficiency occurs due to the difference in the material and shape of the rotor shaft 1 and the processing state at the time of rolling, the optimum correction according to the individual difference. The data in the correction amount table can be corrected to obtain the correction amount, and appropriate correction can be performed for each lot.

In addition, in step ST6 of the present embodiment, 3 is added to the number of the same center runout amount Y as the denominator of the formula for calculating the feed hack value Xn, but it is not limited to n + 3.
Depending on the shape and material of the rotor shaft 1,
The value added to can be changed appropriately. Further, in this embodiment, the worm is formed on the rotor shaft of the motor, but the present invention is not limited to the shaft. For example, a part of a plate-shaped member used in a straight state is subjected to some processing It is also applicable to the case where a bend occurs in the process.

Further, in the present embodiment, a worm is used as the displacement sensor 3.
Although the contact piece 3b that contacts the outer peripheral surface of 1a is used, if a worm wheel that meshes with the worm 1a is used instead of the contact piece 3b, the portion that actually needs to be centered is directly measured. Highly accurate correction can be performed.

As described above, according to the present invention, when the bending amount of the member corrected based on the correction amount table that gives the correction amount according to the bending amount of the member is out of the allowable value, after correction, The additional correction amount corresponding to the bending amount and the bending direction of is corrected by adding it to the correction amount based on the correction amount table at the time of re-correction,
Next, when the amount of bending that uses the correction value is measured, the correction value is used to perform the correction, so the optimum correction value for the member is automatically obtained according to the characteristics of each individual, especially for each lot. In addition to being able to perform straightening, it is not necessary for the operator to change the setting of the straightening amount each time the lot is changed, so that the efficiency of the work of straightening the bend can be improved, and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of a bending correction apparatus for a member to which the present invention is applied. FIG. 2 is a flowchart showing the operating procedure of the correction device. 1 ... Rotor shaft, 1a ... Worm, 2 ... Runout correction device, 3 ... Displacement sensor, 3a ... Slide shaft, 3b ...
… Abutting piece, 4 …… Pulse motor, 4a …… Drive shaft, 5 ……
Control device, 6 ... Memory unit

Claims (1)

[Claims] 1. A bending correction method for a member of a type in which a member having a bending in one direction is deformed in a direction opposite to the bending direction to correct the member, and a step of measuring a bending amount of the member, A step of correcting the member based on a correction amount table that gives a correction amount in accordance with a plurality of specific bending amount ranges, a process of measuring the bending amount of the member after correction and comparing it with an allowable value, If the bending amount of the subsequent member is out of the allowable value, the portion of the correction amount table corresponding to the correction amount in the correction process is gradually reduced in accordance with the increase in the number of corrections and is fed back to a predetermined value. The value is added and corrected, and the bending direction of the member after the straightening is determined when the bending amount after the straightening is out of the allowable value, and added according to the plurality of specific bending amount ranges after the straightening. Give a correction amount The additional correction amount based on the additional correction amount table is added to the corrected value as a positive value in the same direction as the bending direction before correction and a negative value in the opposite direction, and thereafter. And a step of making the data of the portion of the correction amount table as described above.