JP2004117047A - Method and apparatus for measuring unbalance in body of revolution in shape of extended shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measurement method and a measuring apparatus in the unbalance of a body of revolution in the shape of an extended shaft where the causes of the unbalance can be easily specified. <P>SOLUTION: A load torque is applied to a propeller shaft to measure the amount of initial unbalance at a low rotational speed (S1), and the unbalance is corrected, based on the amount of initial unbalance (S2). After that, the amount of loaded unbalance M1 is measured at a low rotational speed by applying the load torque (S3), the amount of unloaded unbalance M2 is measured at a low rotational speed without applying any load torques (S4), and it is judged whether the amount of unbalance at a slide section is equal to or less than an allowance from a conversion table that is provided in advance, based on the difference between M1 and M2 (S5). Further, the amount of unbalance M3 at a high rotational speed is measured at a high rotational speed without applying any load torque (S6), and it is judged whether the amount of unbalance at a joint section is equal to or less than an allowance from a conversion table that is provided in advance, based on the difference between M2 and M3 (S7). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for measuring unbalance of a long-axis rotating body, and more particularly to a measuring method and a measuring apparatus for measuring an unbalance amount based on vibration generated by rotation of a long-axis rotating body.
[0002]
[Prior art]
The measurement of the unbalance of the propeller shaft in the vehicle is performed at a high rotation speed (for example, 4000 rpm) close to the actual high-speed running of the vehicle. At this time, for those having a slide mechanism at the center of the propeller shaft, measurement is performed by applying a constant load torque to remove imbalance due to rattling of the slide fitting portion. That is, the intrinsic unbalance amount of the shaft caused by the bending or misalignment of the propeller shaft is measured, and the intrinsic unbalance of the shaft is corrected based on the measurement result. At the time of the check after the correction, the imbalance measurement is performed at the same high rotational speed as described above, but without applying the load torque, that is, considering the backlash of the slide fitting portion, and the final judgment is made.
[0003]
On the other hand, the conventional measuring device needs to apply a constant load torque at a high rotational speed when measuring a propeller shaft having a slide mechanism. In order to apply a load torque at a high rotational speed, a large tension is required to prevent the drive belt from slipping between the drive motor and the propeller shaft. However, in a measuring apparatus having an inverted leaf spring type vibration frame as shown in FIG. 12, when a vibration sensor 42 mounted in the vibration frame 34 measures vibration in the The tension of the belt 38 suppresses the vibration, and as a result, the vibration that should be measured cannot be detected, which adversely affects the measurement. Therefore, in order to apply a load torque and measure at a high rotation speed, a structure as shown in FIG. 13 is required. The measuring device shown in FIG. 13 has a structure in which a driving belt 38 is hanged from a spindle 30 on a vibration frame 34 onto a separate spindle 46 connected via a joint 44 to drive the same. Has a structure that does not affect the measurement.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-280991 [Patent Document 2]
JP-A-6-43064
[Problems to be solved by the invention]
Some propeller shafts have a slide mechanism at the center and others have universal joint mechanisms at both ends. In such a propeller shaft, in addition to the inherent unbalance of the shaft caused by bending or misalignment of the propeller shaft, there is also an imbalance caused by rattling of the slide mechanism and the universal joint mechanism. For this reason, when the unbalance measurement is finally performed at a high rotation speed without load torque by the conventional measurement method and the unbalance amount exceeds the allowable amount, the measured unbalance is caused by what. It was difficult to determine whether they were doing.
[0006]
On the other hand, the measuring device for performing the measurement at a high rotational speed by applying the load torque shown in FIG. 13 has a larger and more complicated structure than the measuring device for performing the measurement without applying the load torque shown in FIG. Had become.
[0007]
Therefore, an object of the present invention is to provide a method for measuring the unbalance of a long-axis rotating body, in which the cause of the unbalance can be easily identified. Another object of the present invention is to provide a measuring apparatus which has a simple configuration and is suitable for such a measuring method.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the method for measuring unbalance of a long-axis rotating body according to the present invention includes the steps of: An initial unbalance measuring step of measuring a balance amount, an unbalance correcting step of performing an unbalance correction of the long-axis rotating body based on the initial unbalance amount, and a long-axis rotating body after the unbalance correction. On the other hand, a load imbalance measurement step of applying a load torque and rotating at a predetermined low rotational speed to measure a load imbalance amount, and without applying a load torque to the long shaft-shaped rotating body. By rotating at the same low speed as above, a no-load unbalance measuring step of measuring the no-load unbalance amount, and based on the loaded unbalance amount and the no-load unbalance amount, the long-axis rotation of a body It shall have a slide portion unbalance amount deriving step of deriving the sliding portion unbalance amount due to rattling direction sliding portion.
[0009]
According to the above configuration, in the step of deriving the unbalance amount of the slide portion, the unbalance amount due to the rattling of the slide portion can be measured in the unbalance of the long-axis-shaped rotating body. Cause identification becomes easy.
[0010]
Preferably, the low-rotation amount unbalance amount is measured by rotating the long-axis rotating body having the slide portion unbalance amount equal to or less than a predetermined amount at a predetermined low rotation speed without applying a load torque. A rotational unbalance measurement step, a high rotational unbalance measuring step of measuring the high rotational unbalance amount by rotating at a predetermined high rotational speed without applying a load torque to the long axis rotating body; A universal joint unbalance amount deriving step for deriving a universal joint unbalance amount due to rattling of the universal joint portion of the long-axis rotating body based on the low rotation unbalance amount and the high rotation unbalance amount And
[0011]
According to the above configuration, in the slide part unbalance amount deriving step and the free joint part unbalance amount deriving step, the unbalance amount due to the rattling of the slide part and the unbalance amount due to the rattling of the joint part are reduced. Since they can be measured independently of each other, it is easier to specify the cause when correcting imbalance. In addition, since the number of revolutions in the measurement before the correction of the imbalance is reduced, the life of the vibration frame and the spindle of the measuring device can be extended.
[0012]
In order to achieve the above object, the method for measuring unbalance of a long-axis rotating body according to the present invention includes rotating the long-axis rotating body at a predetermined low rotation speed without applying a load torque. An initial unbalance measurement step of measuring an initial unbalance amount, an unbalance correction step of performing an unbalance correction of the long-axis rotating body based on the initial unbalance amount, and a long axis shape after the unbalance correction. A low-rotational unbalance measurement step of measuring the low-rotational unbalance amount by rotating the rotating body at a predetermined low rotation speed without applying a load torque; A high rotation unbalance measuring step of measuring a high rotation unbalance amount by rotating at a predetermined high rotation speed without multiplying the rotation axis, based on the low rotation unbalance amount and the high rotation unbalance amount, Rotating body A universal joint unbalance amount deriving step of deriving a universal joint unbalanced amount due to backlash of the universal joint, shall have.
[0013]
Preferably, the step of deriving the unbalanced amount of the sliding portion includes the step of deriving the unbalanced amount of the sliding portion based on a conversion table representing a correspondence relationship between the unbalanced amount of the load and the unbalanced amount of the sliding portion. It is assumed that the balance amount is derived.
[0014]
Preferably, the universal joint unbalance amount deriving step is based on a conversion table representing a correspondence relationship between the universal joint unbalance amount and a difference between the low rotation unbalance amount and the high rotation unbalance amount. The joint unbalance amount is derived.
[0015]
Further, the unbalance measuring device for the long axis rotating body suitable for the above measuring method, a spindle to which the long axis rotating body is connected, a vibration frame supported by a plate spring, and rotatably holding the spindle, A driving motor that rotates the spindle via a driving belt, and the spindle to which the long-axis rotating body is connected rotates, based on the vibration of the vibration frame generated with the rotation, An unbalance measurement device for a long-axis rotating body that measures an unbalance amount of a long-axis rotating body, wherein the thickness of the leaf spring is within a measurement rotation range from a predetermined low rotation number to a high rotation number. It is assumed that the thickness is selected so as to ensure a predetermined measurement accuracy.
[0016]
According to the above configuration, the measurement by the above-described measuring method can be realized with only one measuring device, and the configuration is smaller than that of a conventional measuring device for applying a load torque and measuring at a high rotation speed. It is simple and can be miniaturized.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
A method and an apparatus for measuring unbalance of a long axis rotating body according to the present invention are a method and an apparatus for measuring an unbalance generated when a propeller shaft (long axis rotating body) mounted on a vehicle or the like rotates. is there. Therefore, first, the unbalance of the propeller shaft measured by the measuring method and the measuring apparatus according to the present invention will be described with reference to FIGS.
[0018]
1 and 2 are views showing the structure of the propeller shaft. The propeller shaft 10 shown in FIG. 1 has a slide portion 12 at an intermediate portion thereof and joint portions (free joint portions) 14 at both end portions thereof. The propeller shaft 10 shown in FIG. 2 does not have a slide portion, and has joint portions 14 at both ends. The main factors of the unbalance generated when the propeller shaft 10 rotates are the unbalance caused by the rattling of the slide portion 12 and the joint portion 14 and other factors such as the bend and misalignment of the propeller shaft 10. This is due to the inherent imbalance of the shaft. Then, the rattling of the slide portion 12 and the rattling of the joint portion 14 will be described in detail below.
[0019]
3 and 4 are enlarged views of the slide portion 12 in FIG. 1. FIG. 3 shows a state in which the slide portion 12 has rattle, and FIG. 4 shows a state in which rattle has occurred. No state is shown. The slide portion 12 allows the propeller shaft to expand and contract by fitting the cylindrical shaft 16 and the spline shaft 18 so as to be relatively non-rotatable and movable in the axial direction. When the propeller shaft is rotated without applying a load torque, as shown in FIG. 3 (b), the centrifugal force 20 due to the rotation causes the spline fitting portion to be deviated in the radial direction, that is, rattling occurs. As shown in FIG. 3A, the axis centers of the cylindrical shaft 16 and the spline shaft 18 are shifted, and the amount of imbalance increases. On the other hand, when the propeller shaft is rotated by applying a load torque, as shown in FIG. 4B, due to the pressure angle action of the spline teeth provided in the spline fitting portion, as shown in FIG. As described above, the axes of the cylindrical shaft 16 and the spline shaft 18 are aligned, and the amount of unbalance is reduced. As described above, the unbalance amount due to the rattling of the slide portion 12 increases when there is no load torque, and decreases when there is load torque.
[0020]
FIG. 5 is an enlarged view of the joint section 14 in FIG. The joint portion 14 has two axes crossed at a U-shaped distal end crosswise, that is, an X-direction axis 22 and a Y-direction axis 24 rotatably connected about each axis. However, a slight gap exists in the connecting portion in the radial direction of the propeller shaft, and the shaft itself is displaced in the axial direction due to the centrifugal force caused by the rotation of the propeller shaft, and rattling occurs. For this reason, the unbalance amount due to the rattling of the joint portion increases when the rotation speed is high, and decreases when the rotation speed is low.
[0021]
In the foregoing, how rattling of the slide portion and rattling of the joint portion in each propeller shaft have been described has been described. In arriving at the present invention, attention was further focused on the relationship between a plurality of propeller shafts having different degrees of rattling, presence / absence of a load, and high and low rotation speeds.
[0022]
FIG. 6 is a diagram showing the correspondence between the magnitude of the load torque and the amount of unbalance, and shows the correspondence between the magnitude of the load torque and the amount of unbalance for each of two propeller shafts having different degrees of rattling in the slide portion. It is a measurement result. As shown in FIG. 6, both the propeller shaft (small rattle) with large rattling of the slide portion and the propeller shaft (small rattle) with small rattling of the slide portion decrease in the amount of unbalance as the load torque increases. are doing. However, by paying attention to the amount of reduction, a difference between the two propeller shafts can be recognized. That is, the difference between the unbalance amount at the load torque 0 and the unbalance amount at the load torque T is α1 for the small rattling product, α2 for the large rattling product, and α1 <α2. This tendency is general, and the unbalance difference between when the load torque is not applied and when the predetermined load torque is applied, that is, the unbalance difference between the presence and absence of the load torque, and the size of the rattling of the slide portion are A correspondence has been established.
[0023]
FIG. 7 is a diagram illustrating a correspondence relationship between the unbalance difference between the presence and absence of the load torque and the rattling of the slide portion. For each of the plurality of propeller shafts, the magnitude of the rattling and the unbalance difference between the presence and absence of the load torque are shown. Is obtained by measurement, simulation, or the like. If a conversion table as shown in FIG. 7 is acquired in advance, the unbalance difference between the presence and absence of the load torque is measured for the propeller shaft of which the magnitude of the backlash is unknown. The size of the play of the slide portion can be specified.
[0024]
FIG. 8 is a diagram showing a correspondence relationship between the rotation speed and the unbalance amount, and is a result of measuring a correspondence relationship between the rotation speed and the unbalance amount for each of two propeller shafts having different degrees of rattling at the joint portion. is there. As shown in FIG. 8, both the propeller shaft with large rattling at the joint portion (large rattle) and the propeller shaft with small rattling at the joint portion (small rattle) increase the amount of unbalance as the rotation speed increases. are doing. However, by paying attention to the increase, the difference between the two propeller shafts can be recognized. That is, the difference between the unbalance amount at the rotation speed of 2000 rpm and the unbalance amount at the rotation speed of 4000 rpm is β1 for the small rattling product, β2 for the large rattling product, and β1 <β2. This tendency is general, and there is a correspondence between the unbalance difference between the low rotation speed and the high rotation speed, that is, the unbalance difference due to the rotation speed difference, and the size of the joint rattling. I have.
[0025]
FIG. 9 is a diagram illustrating a correspondence relationship between the unbalance difference due to the rotation speed difference and the rattling of the joint portion. For each of the plurality of propeller shafts, the unbalance difference due to the rattling size and the rotation speed difference is shown. Is obtained by measurement, simulation, or the like. If a conversion table as shown in FIG. 9 is obtained in advance, an unbalance difference due to a rotational speed difference is measured for a propeller shaft whose rattling is unknown. It is possible to specify the size of the rattling of the joint.
[0026]
Based on the above-described various items related to the unbalance of the propeller shaft, the method and the measurement device for measuring the unbalance of the long-axis rotating body according to the present invention are realized. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
FIG. 10 shows a preferred embodiment of the method for measuring unbalance of a long-axis rotating body according to the present invention, and FIG. 10 shows the entire method of measuring unbalance of a propeller shaft having a slide portion and a joint portion. It is a flowchart which shows a process. Each step of the flowchart will be described in order.
[0028]
In step 1, an unbalance measurement before correction is performed. At this time, the measurement is performed by applying a load torque having a predetermined magnitude T and rotating the propeller shaft at a predetermined low rotation speed (for example, 2000 rpm). Since the load torque is applied, rattling of the slide portion is small, and rattling of the joint portion is also small due to the low rotation speed. Therefore, it can be understood that the unbalance amount measured in step 1 is an unbalance other than the slide portion and the joint portion, for example, an original unbalance of the shaft caused by bending or misalignment of the propeller shaft. In step 2, the imbalance correction is performed. Since the unbalance measured in step 1 is an inherent unbalance of the shaft caused by bending or misalignment of the propeller shaft, the unbalance is corrected by welding a weight for correcting the balance to the propeller shaft.
[0029]
In step 3, a load torque having a predetermined magnitude T is applied, and an unbalance measurement is performed at a predetermined low rotational speed to obtain a measured value M1 (unloaded unbalance amount). Further, in step 4, without applying a load torque, an unbalance measurement is performed at the same low rotational speed as described above, and a measured value M2 (unloaded unbalance amount) is obtained. In step 5, the measured values M1 and M2 are compared to determine whether the difference is equal to or smaller than the allowable value a. The difference between the measured values M1 and M2 is an imbalance difference between the presence and absence of the load torque, and has a correspondence (see FIG. 7) with the amount of rattling of the slide portion. Therefore, by setting in advance the allowable value a of the unbalance difference between the presence and absence of the load torque corresponding to the allowable value of the rattling of the slide portion, the difference between the measured values M1 and M2 and the allowable value a can be compared. Thus, it is possible to determine whether or not the value is less than or equal to the allowable value of the play of the slide portion. That is, if the difference between M1 and M2 is equal to or smaller than the allowable value a, it is determined (OK) that the difference is equal to or smaller than the allowable value of the rattling of the slide portion, and the process proceeds to step 6. For example, it is determined (NG) that it is larger than the allowable value of the play of the slide portion, and the disassembly investigation is performed.
[0030]
In step 6, unbalance measurement is performed at a predetermined high rotation speed (for example, 4000 rpm) without applying a load torque, and a measurement value M3 (high rotation speed unbalance amount) is obtained. In step 7, the measured values M2 and M3 are compared to determine whether the difference is equal to or smaller than the allowable value b. The difference between the measured values M2 and M3 is an imbalance difference due to a difference in the number of rotations, and has a correspondence (see FIG. 9) with the degree of rattling of the joint. Therefore, by setting in advance the allowable value b of the unbalance difference due to the rotational speed difference corresponding to the allowable value of the rattling of the joint portion, the difference between the measured values M2 and M3 and the allowable value b can be compared. Thus, it can be determined whether or not the value of the rattling of the joint portion is equal to or less than the allowable value. That is, if the difference between M2 and M3 is equal to or smaller than the allowable value b, it is determined (OK) that the joint portion is equal to or smaller than the allowable value of the rattling of the joint portion, and the measurement is terminated. For example, it is determined (NG) that it is larger than the allowable value of the rattling of the joint portion, and the disassembly investigation is performed.
[0031]
As described above, since the unbalance of the propeller shaft having the slide portion and the joint portion can be measured for each main cause, it is easy to specify the cause in the disassembly investigation.
[0032]
FIG. 11 shows another preferred embodiment of the method for measuring unbalance of a long-axis rotating body according to the present invention. FIG. 11 shows the unbalance of a propeller shaft having only a joint portion without a slide portion. 5 is a flowchart illustrating all steps of a measurement method. Each step of the flowchart will be described in order.
[0033]
In step 1, an unbalance measurement before correction is performed. The measurement is performed at a predetermined low rotation speed (for example, 2000 rpm). The rattling of the joint is small due to the low rotation speed. Therefore, it can be understood that the unbalance amount measured in step 1 is the unbalance other than the joint portion, for example, the original unbalance of the shaft caused by the bending or misalignment of the propeller shaft. In step 2, the imbalance correction is performed. Since the unbalance measured in step 1 is an inherent unbalance of the shaft caused by bending or misalignment of the propeller shaft, the unbalance is corrected by welding a weight for correcting the balance to the propeller shaft.
[0034]
In step 3, unbalance measurement is performed at a predetermined low rotation speed without applying load torque to obtain a measurement value M2. In step 4, unbalance measurement is performed at a predetermined high rotation speed (for example, 4000 rpm) without applying a load torque to obtain a measurement value M3. In step 5, the measured values M2 and M3 are compared to determine whether the difference is equal to or smaller than the allowable value b. The difference between the measured values M2 and M3 is an imbalance difference due to a difference in the number of rotations, and has a correspondence (see FIG. 9) with the degree of rattling of the joint. Therefore, by setting in advance the allowable value b of the unbalance difference due to the rotational speed difference corresponding to the allowable value of the rattling of the joint portion, the difference between the measured values M2 and M3 and the allowable value b can be compared. Thus, it can be determined whether or not the value of the rattling of the joint portion is equal to or less than the allowable value. That is, if the difference between M2 and M3 is equal to or smaller than the allowable value b, it is determined (OK) that the joint portion is equal to or smaller than the allowable value of rattling, and the measurement is terminated. If the difference between M2 and M3 is larger than the allowable value b. For example, it is determined (NG) that it is larger than the allowable value of the rattling of the joint portion, and the disassembly investigation is performed.
[0035]
As described above, since the imbalance caused by the joint portion can be measured, it is easy to specify the cause in the disassembly investigation.
[0036]
Next, a preferred embodiment of an apparatus for measuring unbalance of a long-axis rotating body according to the present invention will be described. In the present embodiment, only the thickness of the leaf spring is changed in the measuring apparatus having the inverted leaf spring type vibration frame shown in FIG. 12 used in the description of the conventional technique. Hereinafter, the present embodiment will be described with reference to FIG.
[0037]
In the measuring apparatus according to the present embodiment, at the time of measurement, a propeller shaft is connected to a propeller chuck portion 32 of the spindle 30, and the propeller shaft rotates as the spindle 30 rotates. The spindle 30 is rotatably held by a vibration frame 34, and the vibration frame 34 is supported by a leaf spring 36. A drive motor 40 is connected to the spindle 30 via a drive belt 38, and rotation of the drive motor 40 is transmitted to the spindle 30 via the drive belt 38. That is, the rotation of the driving motor 40 rotates the propeller shaft linked to the spindle 30, and the unbalance of the propeller shaft is measured based on the vibration generated by the rotation. A vibration sensor 42 is mounted in the vibration frame 34 to measure the vibration. As described above, in the measuring device having the inverted leaf spring type vibration frame, the vibration in the direction perpendicular to the leaf spring 36 is measured by the vibration sensor 42 mounted in the vibration frame 34.
[0038]
In the present embodiment, the thickness of the leaf spring 36 is optimally selected so that predetermined measurement accuracy can be ensured under predetermined measurement conditions. The thickness of the leaf spring 36 greatly affects the rigidity of the driving belt 38 with respect to the tension and the measurement sensitivity. That is, the greater the thickness of the leaf spring 36, the higher its rigidity, and a greater load torque can be applied. On the other hand, the thicker the leaf spring 36 is, the slower the vibration detection is, and the lower the measurement sensitivity is. Therefore, for example, in accordance with the measurement conditions in which the measurement apparatus of the present embodiment is used, for example, measurement at a predetermined low rotation speed (for example, 2000 rpm) with a load torque of a predetermined magnitude T applied, and The thickness of the leaf spring 36 is set so that a predetermined measurement accuracy can be ensured in a measurement in a state where no load torque is applied in the rotation speed range (for example, 2000 to 4000 rpm). At this time, the measurement by applying the load torque is performed only at a low rotation speed, and does not require a large tension on the driving belt 38, so that the tension of the driving belt 38 does not suppress the vibration. By setting the thickness of the leaf spring in this way, this measuring device can be used in the method for measuring unbalance of a long-axis-shaped rotating body according to the present invention. That is, the above-described measuring method can be realized with only one measuring device. Further, as compared with the conventional measuring apparatus shown in FIG. 13, there is no need to provide a separate spindle, so that the configuration is simplified and the size can be reduced.
[0039]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a method for measuring the unbalance of a long-axis rotating body in which the cause of the unbalance can be easily identified. A suitable measuring device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a structure of a propeller shaft.
FIG. 2 is a diagram showing a structure of a propeller shaft.
FIG. 3 is a view showing a sliding portion of a propeller shaft.
FIG. 4 is a view showing a sliding portion of a propeller shaft.
FIG. 5 is a view showing a joint portion of a propeller shaft.
FIG. 6 is a diagram showing a correspondence relationship between a magnitude of a load torque and an unbalance amount.
FIG. 7 is a diagram showing a correspondence relationship between an unbalance difference in presence / absence of load torque and a degree of rattling of a slide portion.
FIG. 8 is a diagram illustrating a correspondence relationship between a rotation speed and an unbalance amount.
FIG. 9 is a diagram showing a correspondence relationship between an unbalance difference due to a rotational speed difference and a degree of rattling of a joint portion.
FIG. 10 is a flowchart showing a preferred embodiment of a method for measuring unbalance of a long axis rotating body according to the present invention.
FIG. 11 is a flowchart showing another preferred embodiment of the method for measuring unbalance of a long axis rotating body according to the present invention.
FIG. 12 is a diagram showing a measuring device having an inverted leaf spring type vibration frame.
FIG. 13 is a diagram showing a conventional measuring device for performing measurement at a high rotation speed by applying a load torque.
[Explanation of symbols]
10 propeller shaft, 12 slide part, 14 joint part, 30 spindle, 34 vibration frame, 36 leaf spring, 40 drive motor, 42 vibration sensor.

Claims (6)

An initial unbalance measuring step of applying a load torque to the long-axis rotating body and rotating at a predetermined low rotation speed to measure an initial unbalance amount,
An unbalance correction step of performing an unbalance correction of the long-axis rotating body based on the initial unbalance amount,
A loaded unbalance measurement step of measuring the loaded unbalance amount by applying a load torque to the long-axis rotating body after the unbalance correction and rotating at a predetermined low rotation speed,
No-load unbalance measurement step of measuring the no-load unbalance amount by rotating the long-axis rotating body at the same low rotation speed as described above without applying a load torque,
A slide portion unbalance amount deriving step for deriving a slide portion unbalance amount due to rattling of the axial slide portion of the long-axis rotating body based on the loaded unbalance amount and the unloaded unbalance amount; When,
The method for measuring unbalance of a long axis rotating body, comprising: The method for measuring unbalance of a long axis rotating body according to claim 1,
A low-rotational unbalance that measures the low-rotational unbalance amount by rotating the long-axis rotating body having the slide portion unbalance amount of a predetermined amount or less at a predetermined low rotation speed without applying a load torque. The measuring process,
A high-rotational unbalance measurement step of measuring the high-rotational unbalance amount by rotating the long-axis rotating body at a predetermined high rotation speed without applying a load torque;
Deriving a universal joint unbalance amount that derives a universal joint unbalance amount due to rattling of the universal joint portion of the long-axis rotating body based on the low rotation unbalance amount and the high rotation unbalance amount. Process and
The method for measuring unbalance of a long axis rotating body, comprising: An initial unbalance measuring step of measuring the initial unbalance amount by rotating the long shaft-shaped rotating body at a predetermined low rotation speed without applying a load torque, and the long axis is determined based on the initial unbalance amount. An imbalance correction step for correcting the imbalance of the rotating body
A low-rotation unbalance measurement step of measuring the low-rotation unbalance amount by rotating the long-axis rotating body after the unbalance correction at a predetermined low rotation speed without applying a load torque,
A high-rotational unbalance measurement step of measuring the high-rotational unbalance amount by rotating the long-axis rotating body at a predetermined high rotation speed without applying a load torque;
A universal joint unbalance amount deriving step for deriving a universal joint unbalance amount due to rattling of the universal joint portion of the long-axis rotating body based on the low rotation unbalance amount and the high rotation unbalance amount When,
The method for measuring unbalance of a long axis rotating body, comprising: The method for measuring unbalance of a long-axis rotating body according to claim 1 or 2,
The slide unit unbalance amount deriving step includes: calculating the slide unit unbalance amount based on a conversion table representing a correspondence relationship between the load unbalance amount and the no-load unbalance amount with respect to a difference between the slide unit unbalance amount. Derived method for measuring the unbalance of a long axis rotating body. The method for measuring unbalance of a long-axis rotating body according to claim 2 or 3,
The universal joint unbalance amount deriving step is based on a conversion table representing a correspondence relationship between the low rotational unbalance amount and the high rotational unbalance amount and the universal joint unbalance amount. A method for measuring the unbalance of a long axis rotating body, which derives the balance amount. A spindle to which the long rotating body is connected;
A vibration frame supported by a leaf spring and rotatably holding the spindle;
A drive motor for rotating the spindle via a drive belt,
A spindle connected to the long-axis rotating body rotates, and a long-axis rotation for measuring an unbalance amount of the long-axis rotating body based on vibration of a vibration frame generated by the rotation. A body unbalance measuring device,
An apparatus for measuring unbalance of a long-axis-shaped rotating body, wherein the thickness of the leaf spring is selected to be a thickness that can ensure a predetermined measurement accuracy within a measurement rotation range from a predetermined low rotation number to a high rotation number.

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