KR20180013631A - Quality Inspection Method of Brake Disk Using Natural Frequency - Google Patents

Abstract

According to the present invention, a quality inspection method of a brake disk using a natural frequency comprises: a step (a) of applying vibration to a brake disk; a step (b) of calculating a frequency response function for the brake disk; a step (C) of determining whether at least any one of natural frequencies for each mode of the frequency response function calculated by the step (b) is included in a reference deviation for each preset mode; and a step (d) of performing a follow-up action according to a determination result of the step (c).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method of inspecting the quality of a natural frequency of a brake disk, and more particularly, to a method of inspecting the quality of a natural frequency of a brake disk capable of minimizing noise by avoiding resonance between components,

As an effort to reduce the noise generated during braking of the brake disc, a technology that is emerging in recent years is a technique for avoiding resonance between components of a brake connector module (BCM) using the natural frequency of the product.

Resonance occurs when the energy introduced during braking is excited energy (EXCITED ENERGY) and the natural frequencies between the components are equal or coincident with each other. In case of MODE COUPLING, the FEED-BACK SYSTEM As a result, vibrations between components are increased and noise is generated.

  Therefore, in order to reduce the noise or joint noise of the brake, it is necessary to reduce the possibility of resonance by separating the natural frequencies between the components by using an active method.

As a method for avoiding resonance between BCM parts, there is used a method of modifying the shape of the brake pad and changing the material of the pad to a material having improved vibration damping performance in addition to a conventional method of reducing noise through a matching test , And in the case of the Kelpiper, a method of adjusting the resonance frequency by adding mass to the torque member is used.

In the case of brake discs, the target frequency to avoid resonance is set, and the shape optimized for the natural frequency is realized by the product through casting and machining. Another tendency is to provide structural asymmetry to individual parts, There is a way to avoid the problem.

However, most of the brake discs developed recently have satisfactory basic specifications as a braking device, but still suffer from the problem of noise called squeeze noise, which causes a lot of cost.

In addition, the conventional management method of the disc shape tolerance which has been carried out in order to minimize the vibration and noise of the brake disc shows a limit of noise reduction and increases a high production cost.

Therefore, a method for solving such problems is required.

Korea Public Utility Model No. 20-1998-013670

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the conventional art, and has an object to provide an efficient natural frequency quality inspection method of a brake disk.

Also, it has a purpose to design / manufacture a brake disc optimized for the target natural frequency in order to reduce braking noise.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to another aspect of the present invention, there is provided a method of inspecting the quality of a natural frequency of a brake disk, the method comprising: (a) applying vibration to the brake disk; (b) calculating a frequency response function for the brake disk; (c) determining whether at least one of the frequency-dependent natural frequency of the frequency response function calculated in the step (b) is included in the reference deviation for each of the predetermined modes, and (c) And (d) performing an action.

The step (d) includes the steps of: (d-1) ending the test when the natural frequency of the frequency response function is included in the reference deviation, and And (d-2) modifying a corresponding region of the brake disc 1 related to the mode if it is not included in the reference deviation.

After the step (d-2), the steps (a) to (d) may be repeated.

The frequency response function may include at least one of an OPU mode, an OPD mode, an OPT mode, an IPR mode, and an IPC mode.

The step (d-2) may correct the neck of the brake disk when the natural frequency of the OPU mode among the frequency response functions is not included in the reference deviation.

In the step (d-2), when the natural frequency of the OPD mode among the frequency response functions is not included in the reference deviation, the thickness of the disk part of the brake disk may be modified.

In the step (d-2), when the natural frequency of at least one of the IPR mode and the IPC mode among the frequency response functions is not included in the reference deviation, the outer diameter of the horn of the brake disk may be modified.

The method for inspecting the natural frequency of a brake disk according to the present invention for solving the above problems has the following effects.

First, there is an advantage that noise can be minimized by avoiding resonance between the components of the brake disc through precise quality inspection.

Second, there is an advantage that rapid and efficient quality inspection is possible by minimizing loss during inspection process.

Third, there is an advantage that mass production of uniform quality products can be achieved while increasing the yield.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart illustrating a method of checking a natural frequency quality of a brake disk according to an embodiment of the present invention;
2 and 3 are views showing a state of a brake disk;
FIG. 4 is a diagram illustrating a correction area of a brake disk according to a mode of a frequency response function, according to an embodiment of the present invention.
Fig. 5 shows a variant of the brake disc according to the OPU mode; Fig.
6 is a view showing deformation of the brake disc according to the OPD mode;
7 is a view showing a variation of the brake disk according to the OPT mode;
8 is a view showing a variation of the brake disk according to the IPR mode; And
9 is a view showing deformation of the brake disk according to the IPC mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted.

FIG. 1 is a flowchart illustrating a method of checking a natural frequency quality of a brake disk according to an embodiment of the present invention. Referring to FIG.

As shown in FIG. 1, a method for inspecting the quality of a brake disk according to an embodiment of the present invention includes the steps of (a) applying vibration to a brake disk, (b) calculating a frequency response function for the brake disk, (C) determining whether at least one of the frequency-dependent natural frequencies of the frequency response function calculated in the step (b) is included in a reference deviation of each of the predetermined modes; and (c) And (d) performing a follow-up action according to the determination result of the step (d).

In the step (a), vibration is applied to the brake disk to calculate a frequency response function of the brake disk.

That is, when vibrations are applied to the brake disk, the natural frequencies of various modes are displayed on the brake disk, and the process of applying the vibration can be performed through various known equipments.

In the step (b), a frequency response function is calculated by detecting and collecting various types of vibrations as vibration is applied to the brake disk through the step (a).

Specifically, the frequency response function represents the response output of the brake disk in a frequency relationship, and may include various modes depending on the amplitude ratio and the difference. Each of these modes can correspond to a specific type of deformation occurring in the brake disc. In the present invention, it is possible to perform close inspection of the brake disc.

For example, in the present embodiment, the frequency response function may include at least one of an OPU mode, an OPD mode, an OPT mode, an IPR mode, and an IPC mode, which will be described later.

In the step (c), it is determined whether at least one of the frequency-dependent natural frequencies of the frequency response function calculated in the step (b) is included in the reference deviation of each predetermined mode.

Here, the reference deviation refers to a product error that can be judged as a good product for each mode, and it may be set differently for each mode.

Also, if it is determined that any one of the frequency-dependent natural frequencies of the frequency response function is out of the reference deviation in the process, it is determined that the product does not satisfy the quality acceptance criterion.

The step (d) may be a step of performing a follow-up action according to the determination result of step (c). In the case of step (c) It is possible to perform different actions through whether or not the reference deviation is exceeded.

More specifically, the step (d) includes the steps of (d-1) ending the inspection when it is determined that the product satisfies the quality acceptance criterion and the inspection is ended when the frequency-response function includes all of the natural frequencies of the modes in the reference deviation .

In the step (d), if the frequency-response function is not included in the reference deviation, the mode determining unit determines that the product does not satisfy the quality acceptance criterion, The corresponding area of the associated brake disc is re-established.

After the re-checking operation, the steps (a) to (d) may be repeated to re-verify.

In the conventional case, when it is judged that the product does not satisfy the quality acceptance criterion, the parts to be corrected through the detailed inspection of each part of the brake disk were found and corrected. As a result, not only the time loss due to the close inspection process is excessively generated, but also the inspection process is performed with low precision, and the reassessment operation is performed a plurality of times.

On the other hand, according to the present invention, since the frequency response function is calculated, the natural frequency of each mode is compared with the reference deviation, and the natural frequency corresponding region of the brake disk corresponding to the mode deviates from the reference deviation is corrected. It is possible to carry out an efficient inspection by performing only the minimum operation without going through the process.

2 and 3 are views showing a state of the brake disc 1. [

2 and 3, the brake disk 1 generally includes a HAT portion 10, a neck portion 20, and a disk portion 30, .

FIG. 4 is a diagram illustrating a correction area of a brake disk according to a mode of a frequency response function, in a method for inspecting a natural frequency of a brake disk according to an embodiment of the present invention. FIG.

As described above, in this embodiment, the frequency response function may include at least one of an OPU mode, an OPD mode, an OPT mode, an IPR mode, and an IPC mode.

In the case of the Out of Plane Umbrella (OPU) mode, the friction surface with the brake pad represents the natural frequency according to the shape of the umbrella curve. That is, the OPU mode represents a modification based on a line concentric with the circumference of the disc portion 30 of the brake disc, and such a modification is shown in FIG.

In the case of the Out-of-Plane Diameter (OPD) mode, the friction surface with the brake pad represents the natural frequency according to the shape of waving in the circumferential direction. That is, the OPD mode represents a deformation based on the radial direction across the center point of the brake disc, and such deformation is shown in Fig.

In the case of the Out-of-Plane Twisting (OPT) mode, the OPT mode and the OPD mode show the natural frequency according to the combined form. That is, the OPT mode is a combination of a deformation based on a line concentric with the circumference of the disc 30 of the brake disc, and a deformation based on a radial direction of the brake disc that intersects the center of the disc. The modified form is shown in Fig.

At this time, as a method for expressing the OPU mode, the OPD mode and the OPT mode shape more specifically, a NODAL DIAMETER (ND) can be used. Herein, ND means the number of node lines that the disk warps and can be defined as a representation of the form (r, n). Where r is the number of radial nodes and n is the number of circumferential nodes.

That is, in the OPU mode, (1, 0), (2, 0), (3, 0) ... may be expressed according to the number of radial nodal points, Can be expressed as (0, 2), (0, 3), (0,4) ....

In the case of the OPT, the OPU mode and the OPD mode may be combined as (1, 2), (1, 3), (2, 2), (2, 3).

On the other hand, in the case of the IPR (In-Plane Radia) mode, the friction surface of the disk unit 30 shows the natural frequency according to the vibration mode in the direction perpendicular to the axis. That is, the IPR mode represents a deformation of the radius from the center point of the brake disk, which is shown in Fig.

In the case of the IPC (In-Plane Circumferential) mode, the friction surface of the disk unit 30 represents a natural frequency according to the vibration mode in the circumferential direction. That is, the IPC mode represents a deformation in the circumferential direction of the disc portion 30 of the brake disc, and such a modification is shown in Fig.

In this case, the IPR mode and the IPC mode may also use a NODAL DIAMETER (ND) as a method for expressing the shape more specifically.

In particular, the IPR mode can be expressed as IPR2, IPR3, IPR4,... According to the number of points where the radius is reduced, and the IPC mode can be expressed as IPC2, IPC3, IPC4, Can be expressed as follows.

As described above, the present invention can intuitively recognize an area requiring correction of the brake disk by comparing the reference deviation for each mode of the frequency response function.

4, when the natural frequency of the OPU mode among the frequency response functions is not included in the reference deviation, the neck portion 20 of the brake disk is modified The natural frequency of the OPU mode can be incorporated into the reference deviation.

If the natural frequency of the OPD mode among the frequency response functions is not included in the reference deviation, the thickness of the disk unit 30 of the brake disk may be modified so that the natural frequency of the OPD mode is incorporated into the reference deviation .

In addition, when the natural frequency of the OPT mode among the frequency response functions is not included in the reference deviation, the thickness of the neck portion 20 of the brake disk and the thickness of the disk portion 30 are modified so that the natural frequency of the OPT mode is smaller than the reference deviation . ≪ / RTI >

If the natural frequencies of the IPR mode and the IPC mode are not included in the reference deviation, the outer radius of the hood (10) of the brake disk is modified so that the natural frequencies of the IPR mode and the IPC mode So that it can be incorporated into the reference deviation.

As described above, the present invention minimizes the loss during the inspection process through the natural frequency of each mode of the frequency response function, enables fast and efficient natural frequency quality inspection, and can perform accurate natural frequency quality inspection.

Accordingly, it is possible to minimize resonance by avoiding resonance between the components of the brake disc, to increase the yield, and to mass-produce products of uniform quality.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. It is obvious to them. Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

1: Brake disk 10:
20: neck portion 30: disk portion

Claims (7)

(A) applying vibration to the brake disc 1;
(B) calculating a frequency response function for the brake disc (1);
(C) determining whether at least one of the frequency-dependent natural frequency of the frequency response function calculated in the step (b) is included in a reference deviation of each of the predetermined modes; And
(D) performing a follow-up action according to the determination result of the step (c);
Wherein the vibration frequency of the brake disk is set to a predetermined value. The method according to claim 1,
The step (d)
(D-1) ending the test when the mode-specific natural frequency of the frequency response function is included in the reference deviation; And
(D-2) modifying a corresponding region of the brake disk 1 related to the mode if at least one of the frequency-dependent natural frequency of the frequency response function is not included in the reference deviation;
Wherein the vibration frequency of the brake disk is set to a predetermined value. 3. The method of claim 2,
After the step (d-2)
And repeating the steps (a) to (d). 3. The method of claim 2,
The frequency response function may include:
OPT mode, OPD mode, OPT mode, IPR mode, and IPC mode. 5. The method of claim 4,
The step (d-2)
And correcting the neck portion (20) of the brake disc (1) when the natural frequency of the OPU mode among the frequency response functions is not included in the reference deviation. 5. The method of claim 4,
The step (d-2)
And modifying the thickness of the disc portion (30) of the brake disc (1) when the natural frequency of the OPD mode among the frequency response functions is not included in the reference deviation. 5. The method of claim 4,
The step (d-2)
A natural frequency quality inspection method of a brake disk for correcting an outer diameter of a head portion (10) of the brake disk (1) when the natural frequency of at least one of the IPR mode and the IPC mode among the frequency response functions is not included in the reference deviation .

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