JP2005121580A - Balance testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a person superficial in knowledge and experience as to each degree of vibration mode of a testing object correct easily unbalance in the each degree of vibration mode and carry out a balance test easily. <P>SOLUTION: This balance testing method for testing a balance condition of the testing object S when rotating the testing object S is provided with a resonance frequency acquiring process for acquiring a resonance frequency in the each degree of vibration mode of a reference testing object corresponding to the testing object S, a static unbalance correction process for rotating the testing object S at a rotation frequency lower than the resonance frequency in the primary vibration mode, and for correcting the unbalance, and a dynamic unbalance correction process for rotating the testing object S at the rotation frequency lower than the resonance frequency in the primary vibration mode, and for inertia-oscillating the testing object S at the frequency substantially equal to the resonance frequency in the optional degree of vibration mode, so as to correct the unbalance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a balance test method.

Conventionally, the balance state of a rotating component such as a propeller shaft, a micromotor, and a high-speed spindle during high-speed rotation is measured by a balance testing machine (see, for example, Patent Document 1).
In the balance test by the balance tester, both ends of the test body are supported by a support base, the test body is rotated in each order vibration mode, and the unbalance at the resonance frequency in each order vibration mode is corrected. .
JP 2001-91394 A

  However, in the balance test method as described above, it is necessary to know the resonance frequency for each vibration mode based on the structure and shape of the specimen, and to correct the unbalance after considering this, It was difficult for a person with little knowledge or experience to perform a balance test. In addition, since it is necessary to sequentially correct the unbalance in each order vibration mode, the balance test takes time and effort.

  Accordingly, an object of the present invention is to enable even a person who has little knowledge or experience about the vibration mode of each order of the test body to easily correct the unbalance in the vibration mode of each order, and to easily perform the balance test. It is to provide a balance test method that can.

  In order to solve the above problems, the invention described in claim 1 is a balance test method for testing a balance state of a test body when the test body (S) is rotated, for example, as shown in FIG. A resonance frequency acquisition step of acquiring a resonance frequency in each order vibration mode of the reference test body corresponding to the test body, and rotating the test body at a rotation frequency lower than the resonance frequency in the primary vibration mode, thereby causing an unbalance. A static unbalance correction step of correcting the test body, and rotating the test body at a rotation frequency lower than the resonance frequency in the primary vibration mode, and subjecting the test body to inertia excitation at a frequency substantially equal to the resonance frequency in the vibration mode of any order, A dynamic unbalance correction step of correcting the unbalance.

  The invention according to claim 2 is a balance test method for testing a balance state of a test body when the test body (S) is rotated as shown in FIG. 1, for example, and corresponds to the test body. A resonance frequency acquisition step of acquiring a resonance frequency in each order vibration mode of the reference test body; and a static unbalance correction step of correcting the unbalance by rotating the test body at a rotation frequency in a predetermined order vibration mode. The specimen is rotated at a rotational frequency in a predetermined order vibration mode, and is subjected to inertial excitation at a frequency substantially equal to the resonance frequency in a higher order vibration mode than the predetermined order vibration mode to correct the imbalance. And a dynamic unbalance correction step.

  According to the first aspect of the present invention, the resonance frequency in the vibration mode of each order of the reference test body is acquired by the resonance frequency acquisition step, and the test body is more than the resonance frequency in the primary vibration mode by the static unbalance correction step. Rotate at low rotational frequency to correct unbalance. Then, the dynamic unbalance correction process rotates the test specimen at a rotation frequency lower than the resonance frequency in the primary vibration mode, and inertially vibrates at a frequency substantially equal to the resonance frequency in the vibration mode of an arbitrary order. Correct it.

  Thereby, in a state where the rotation frequency of the test body is maintained in the primary vibration mode, the test body can be resonated in an arbitrary vibration mode that is generated at or above the rotation frequency of the test body. That is, in order to correct the imbalance in the higher-order vibration mode of the test body, it is usually necessary to rotate the test body at a rotation frequency corresponding to the vibration mode, but this is not necessary in the present invention. Instead, by forcibly applying vibration generated in the higher-order vibration mode to the test body, the same state as a normal balance test can be developed in the test body.

  Therefore, a person who performs a balance test need only measure the resonance frequency of each order vibration mode in advance, and consider each order vibration mode based on the structure and shape of the specimen for each balance test. This eliminates the need to adjust the rotational frequency of the specimen. Therefore, even a person who has little knowledge and experience regarding the vibration modes of each order of the test body can easily correct the unbalance of the vibration modes of each order and can easily perform a balance test.

  According to the second aspect of the present invention, the resonance frequency in the vibration mode of each order of the same reference test body as the test body is acquired by the resonance frequency acquisition step, and the test body is given a predetermined value by the static unbalance correction step. Rotate at the rotation frequency in the order vibration mode to correct the imbalance. Then, the dynamic unbalance correction process rotates the specimen at the rotation frequency in the vibration mode of the predetermined order and inertial excitation at a frequency substantially equal to the resonance frequency in the vibration mode of the higher order than the vibration mode of the predetermined order. And correct the imbalance.

  This allows the test body to resonate in a vibration mode with a higher order than the vibration mode of the predetermined order generated at or above the rotational frequency of the test body while maintaining the rotational frequency of the test body in the vibration mode of the predetermined order. Can do. That is, in order to correct the imbalance in the higher-order vibration mode of the test body, it is usually necessary to rotate the test body at a rotation frequency corresponding to the vibration mode, but this is not necessary in the present invention. Instead, by forcibly applying vibration generated in the higher-order vibration mode to the test body, the same state as a normal balance test can be developed in the test body.

  Therefore, a person who performs a balance test need only measure the resonance frequency of each order vibration mode in advance, and consider each order vibration mode based on the structure and shape of the specimen for each balance test. This eliminates the need to adjust the rotational frequency of the specimen. Therefore, even a person who has little knowledge and experience regarding the vibration modes of each order of the test body can easily correct the unbalance of the vibration modes of each order and can easily perform a balance test.

Hereinafter, the best mode of a balance test method according to the present invention will be described in detail with reference to the drawings. In carrying out the present invention, a horizontal balance testing machine will be described as an example as a balancing test.
As shown in FIG. 1 to FIG. 4, the balance testing machine 100 tests the balance state of the test body S when the test body S is rotated, and the motor 1 as a driving means for rotating the test body S. A support unit 2 that supports the test body S, a support unit vibration device 3 that vibrates the support unit 2 in a predetermined direction, a gantry 4 on which the support unit 2 and the support unit vibration device 3 are installed, and a power source for the motor 1. A rotation control unit 6 serving as a rotation control unit that controls the motor 1 so as to rotate the test body S at a rotation frequency lower than the resonance frequency in the primary vibration mode. As an excitation frequency control unit that is connected to an excitation power source 7 serving as a power source and controls the support unit excitation device 3 so as to perform inertia excitation at a frequency substantially equal to the resonance frequency in the vibration mode of an arbitrary order of the specimen S. Excitation frequency control unit 8 etc. It is provided.

  As shown in FIG. 1, the support portion 2 is composed of a roller bearing, and two rollers 22 for placing the test body S on the upper end portion of the substantially T-shaped roller support 21 are arranged in the width direction of the roller support 21. It is provided side by side. The test body S is placed so as to be in contact with the outer circumferences of the two rollers 22, and the rotational force acting on the support portion 2 when the test body S is rotated can be absorbed by the roller 22 rotating. It is like that.

  As shown in FIG. 2, the support portion vibration device 3 is provided on the lower end side of the roller support 21 of the support portion 2, and has an inner magnetic pole 31 that is magnetized by one magnetic pole and an outer magnetic pole that is magnetized by the other magnetic pole. 32, an exciting coil 33 as a direct-current magnetic field forming part for forming a direct-current magnetic field, a movable coil 34 arranged in a direct-current magnetic field formed by the exciting coil 33, an air spring 35 for supporting the roller support 21, and the like.

The inner magnetic pole 31 supports the roller support 21 via the air spring 35 and is a magnetic body that is magnetized to a magnetic pole different from the outer magnetic pole 32 by the excitation coil 33.
The outer magnetic pole 32 is a magnetic body that is provided outside the inner magnetic pole 31 and is magnetized by the exciting coil 33.

  The exciting coil 33 is housed so as to be surrounded by the outer periphery of the outer magnetic pole 32, and is provided in two layers in the vertical direction with a protrusion 32a formed along the circumference on the wall surface of the outer magnetic pole 32. . The excitation coil 33 is connected to the excitation power source 7 shown in FIG. 4, and when a direct current is passed from the excitation power source 7, the protrusion 32 a of the outer magnetic pole 32 that is a magnetic body and the inner magnetic pole 31 are connected. A direct current magnetic field across the movable coil 34 is formed in the gap G therebetween.

  The movable coil 34 is connected to the excitation power source 7, and when an alternating current is applied from the excitation power source 7, the movable coil 34 moves through the DC magnetic field formed in the gap G based on the frequency of the alternating current. Vibrate. The movable coil 34 is fixed to the lower end portion of the roller support 21 of the support portion 2 supported by the air spring 35 attached to the upper surface of the inner magnetic pole 31, and the roller support is supported by the vibration of the movable coil 34. 21 vibrates.

As shown in FIG. 1, the gantry 4 has a recess 4 a that is open on the upper surface, and the support portion vibration device 3 is provided at the bottom of the recess 4 a. In addition, a part of the roller support 21 to which the support portion vibration device 3 is fixed is inserted into the recess 4a. Further, the width of the concave portion 4a is slightly wider than the width of the roller support 21, and the roller support 21 can vibrate in the vertical direction in the concave portion 4a, but almost vibrates in the width direction. In other words, the specimen S can be subjected to so-called inertia excitation.
A plate spring material 41 that vibrates with the unbalance of the test body S is provided on the lower surface of the gantry 4. The vibration characteristics of the plate spring material 41 are detected by a detector 42, and a test is performed based on the detected result. The unbalance of the body S is corrected.

As shown in FIG. 3, the rotation control unit 6 is connected to a drive power source 5 that is a power source of the motor 1, and controls the motor 1 to rotate the specimen S at a rotation frequency in the primary vibration mode.
Specifically, the rotation control unit 6 transmits a control signal to the drive power supply 5 to control the current supplied to the motor 1 from the drive power supply 5, and controls the CPU 61 and the work area of the CPU 61 that control the rotation frequency of the motor 1. A RAM 62 to be formed and a ROM 63 storing a rotation control program for controlling the rotation frequency of the motor 1 are provided.

As shown in FIG. 4, the vibration frequency control unit 8 is configured to vibrate the test body S with vibrations having a frequency substantially equal to the resonance frequency in an arbitrary order vibration mode of the test body S. To control.
Specifically, the vibration frequency control unit 8 transmits a control signal to the vibration power source 7 to control the current supplied from the vibration power source 7 to the support unit vibration device 3, so that the roller support 21 is vibrated. A CPU 81 for controlling the frequency, a RAM 82 for forming a work area of the CPU 81, a ROM 83 for storing an excitation frequency control program for controlling the excitation frequency of the roller support 21, and the like are provided.

  Next, a method for performing a balance test of the specimen S using the balance testing machine 100 having the above configuration will be described.

[Balance test below resonance frequency in primary vibration mode]
First, the resonance frequency corresponding to the vibration mode of each order of the reference test body corresponding to the test body S is acquired (resonance frequency acquisition step). In this step, the resonance frequency in each vibration mode is acquired while gradually increasing the rotational frequency of the reference specimen as in the normal balance test. Assume that the vibration characteristics as shown in FIG. 5 are obtained. Here, f1 is a resonance frequency in the primary vibration mode, f2 is a resonance frequency in the secondary vibration mode, f3 is a resonance frequency in the tertiary vibration mode, f4 is a resonance frequency in the fourth vibration mode, and f5 is a resonance frequency in the fifth vibration mode. It is.

Next, both ends of the test body S are placed on the roller 22, one end is connected to the motor 1, and the CPU 61 of the rotation control unit 6 executes the rotation control program, thereby controlling the drive power source 5 and the motor. The rotational frequency of 1 is controlled, and the specimen S is rotated at a rotational frequency lower than the resonance frequency in the primary vibration mode, that is, in a static state. The rotation frequency at this time is assumed to be fa. When an unbalance is detected by the detector 42, the unbalance is corrected (static unbalance correction step).
Next, the CPU 81 of the vibration frequency control unit 8 executes the vibration frequency control program, thereby controlling the vibration power supply 7 and subjecting the specimen S to inertial vibration. When an unbalance is detected by the detector 42, the unbalance is corrected (dynamic unbalance correction step). Here, for example, when the test body S is subjected to inertial vibration at the resonance frequency f3, the test body S is resonated in the tertiary vibration mode while rotating at the rotation frequency fa. If the imbalance is corrected in this state, the resonance frequency f1 in the primary vibration mode and the resonance frequency f2 in the secondary vibration mode are lower than f3, so the resonance frequency in the middle of reaching f3 is skipped. This makes it possible to correct unbalance in higher vibration modes.

[Balance test at rotational frequency in a predetermined order vibration mode]
First, the resonance frequency corresponding to the vibration mode of each order of the reference test body corresponding to the test body S is acquired (resonance frequency acquisition step). In this step, the resonance frequency in each vibration mode is acquired while gradually increasing the rotational frequency of the reference specimen as in the normal balance test. Assume that the vibration characteristics as shown in FIG. 5 are obtained. Here, f1 is the resonance frequency in the primary vibration mode, f2 is the resonance frequency in the secondary vibration mode, f3 is the resonance frequency in the tertiary vibration mode, f4 is the resonance frequency in the fourth vibration mode, and f5 is the resonance frequency in the fifth vibration mode. It is.

Next, both ends of the test body S are placed on the roller 22, one end is connected to the motor 1, and the CPU 61 of the rotation control unit 6 executes the rotation control program, thereby controlling the drive power source 5 and the motor. The rotational frequency of 1 is controlled, and the specimen S is rotated at the rotational frequency in the vibration mode of a predetermined order (for example, primary). The rotation frequency at this time is assumed to be fb. When an unbalance is detected by the detector 42, the unbalance is corrected (static unbalance correction step).
Next, the CPU 81 of the vibration frequency control unit 8 executes the vibration frequency control program, thereby controlling the vibration power supply 7 and subjecting the specimen S to inertial vibration. When an unbalance is detected by the detector 42, the unbalance is corrected (dynamic unbalance correction step). Here, for example, when the test body S is subjected to inertia vibration at the resonance frequency f4, the test body S is resonated in the fourth-order vibration mode while rotating at the rotation frequency fb. If the imbalance is corrected in this state, the resonance frequency f2 in the secondary vibration mode and the resonance frequency f3 in the tertiary vibration mode are lower than f4, so the resonance frequency in the middle of reaching f4 is skipped. This makes it possible to correct unbalance in higher vibration modes.

  By performing the balance test of the specimen S in this way, it is not necessary to correct the unbalance in all vibration modes, so that the time required for the balance test can be shortened and labor can be saved. Moreover, since the balance test can be performed while maintaining the state where the rotational frequency of the test body S is low, the motor 1 that rotates the test body S can be downsized.

  According to the balance testing machine 100 of the present embodiment, the support unit 2 supports the test body S, and the motor 1 controlled by the rotation control unit 6 rotates the test body S at a rotation frequency lower than the resonance frequency in the primary vibration mode. Rotate with Further, the support portion vibration device 3 controlled by the vibration frequency control unit 8 inertially vibrates the test body S at a frequency substantially equal to the resonance frequency in the vibration mode of an arbitrary order of the test body S.

  Thereby, the test body S can be made to resonate in any vibration mode that occurs at or above the rotation frequency of the test body S in a state where the rotation frequency of the test body S is maintained in the primary vibration mode. That is, in order to correct the unbalance in the higher-order vibration mode of the test body S, it is usually necessary to rotate the test body S at a rotation frequency corresponding to the vibration mode, but this is necessary in the present invention. Absent. Instead, by forcibly applying vibration generated in the higher-order vibration mode to the specimen S, it is possible to cause the specimen S to develop the same state as a normal balance test.

  Therefore, a person who performs a balance test need only measure the resonance frequency of each order vibration mode in advance, and consider each order vibration mode based on the structure and shape of the specimen S for each balance test. Thus, it is not necessary to adjust the rotation frequency of the test body S. Therefore, even a person who has little knowledge and experience about the vibration modes of each order of the test body S can easily correct the unbalance of the vibration modes of each order, and can easily perform a balance test.

  The exciting coil 33 is energized with a direct current to form a direct current magnetic field, and the movable coil 34 disposed in the direct current magnetic field formed by the exciting coil 33 is energized with an alternating current to form an alternating magnetic field. Drive up and down. Here, since the movable coil 34 is provided on the lower end side of the roller support 21, the roller support 21 and the roller 22 are also driven in the vertical direction when the movable coil 34 is driven in the vertical direction.

  Therefore, the test body S is not subjected to displacement via the support portion 2, but a force necessary to vibrate is applied, so that the test body S can realize resonance in each order of vibration mode. Can do.

The present invention is not limited to the above embodiment. For example, the rotational frequency of the specimen S may be rotated at the rotational frequency in the secondary vibration mode, and inertial excitation may be performed at the resonance frequency in the tertiary vibration mode. Further, instead of supporting the test body S with the two rollers 22, the structure is such that the ball bearings are supported around both ends of the test body S and supported by an elastic member, for example, a spring. good. Furthermore, the support portion vibration device 3 is not limited to the one having the above structure, and the number of exciting coils 33 may be one.
Further, as shown in FIG. 6, the support portion vibration device 3 may be one in which a power source is connected to the piezoelectric element 11. With this configuration, when a voltage is applied to the piezoelectric element 11, the piezoelectric element 11 is distorted, and the support portion 2 can be vibrated by repeating ON / OFF of the voltage. In addition, the present invention can be freely changed and improved without departing from the gist of the invention.

It is a perspective view of the balance testing machine in an embodiment of the invention. It is sectional drawing of the support part vibration apparatus in embodiment of this invention. It is explanatory drawing of the rotation control part in embodiment of this invention. It is explanatory drawing of the excitation frequency control part in embodiment of this invention. It is explanatory drawing of the balance test method in embodiment of this invention. It is a perspective view of the balance testing machine in other examples of an embodiment of the invention.

Explanation of symbols

1 Motor (drive means)
2 Support unit 3 Support unit excitation device 33 Excitation coil (DC magnetic field forming unit)
34 Movable coil 6 Rotation control unit (Rotation control means)
11 Piezoelectric element 8 Excitation frequency control section (Excitation frequency control means)
100 Balance testing machine S Specimen

Claims (2)

A balance test method for testing a balance state of a specimen when the specimen is rotated,
Resonance frequency acquisition step of acquiring a resonance frequency in each vibration mode of a reference test body corresponding to the test body;
A static unbalance correction step of rotating the test body at a rotation frequency lower than the resonance frequency in the primary vibration mode to correct the unbalance;
A dynamic unbalance correction step of correcting the unbalance by rotating the test body at a rotation frequency lower than the resonance frequency in the primary vibration mode and subjecting the test body to inertia excitation at a frequency substantially equal to the resonance frequency in the vibration mode of any order. When,
A balance test method characterized by comprising: A balance test method for testing a balance state of a specimen when the specimen is rotated,
Resonance frequency acquisition step of acquiring the resonance frequency in each order vibration mode of the reference test body corresponding to the test body;
A static unbalance correction step of rotating the test body at a rotation frequency in a vibration mode of a predetermined order and correcting the unbalance;
The test specimen is rotated at a rotational frequency in a predetermined order vibration mode, and is subjected to inertial excitation at a frequency substantially equal to the resonance frequency in a higher order vibration mode than the predetermined order vibration mode to correct the imbalance. Dynamic unbalance correction process;
A balance test method characterized by comprising:

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