JP2018013445A - Shape evaluation method of vertebra - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape evaluation method of a vertebra which is capable of suppressing the influence of noise during measurement, and performing the management of a curved shape of a vertebra highly accurately.SOLUTION: A shape evaluation method of a vertebra comprises: a process S101 of acquiring the shape data of the vertebra; a process S102 of transforming an acquired shape data into a displacement axis waveform; a process S103 of performing fast Fourier transform processing to the displacement axis waveform and transforming the waveform into a spectrum waveform; a process S104 of removing a prescribed degree or more of a component from the spectrum waveform; a process S105 of performing inverse fast Fourier transform processing to the spectrum waveform from which the component is removed and transforming the waveform into the displacement axis waveform; and processes S106, S107 of evaluating the shape of the vertebra based on the shape data of the vertebra obtained based on the displacement axis waveform which is transformed by inverse fast Fourier transform processing.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for evaluating the shape of a vertebra constituting a wiper blade that wipes, for example, a window of a vehicle.

  Vehicles such as passenger cars, buses, and trucks are provided with wiper devices that wipe windows and the like. The wiper device includes a wiper arm that is driven to swing by a motor provided in the vehicle, and a wiper blade that is attached to the tip of the wiper arm.

  The wiper blade includes a blade holder attached to the tip of the wiper arm, and a blade rubber made of a rubber material that is detachably held by the blade holder and pressed against a window or the like.

  The wiper blade has a structure in which the pressing force applied from the wiper arm is evenly distributed over the entire longitudinal direction in order to improve the wiping property.

  For example, in Patent Document 1, a leaf spring (vertebra) formed in a curved shape that curves more strongly than the window glass toward the window glass is attached to the blade rubber, and the leaf spring is applied to the window glass by the pressing force from the wiper arm. A configuration for elastic deformation to a shape along is disclosed. According to this configuration, the pressing force from the wiper arm is dispersed in the longitudinal direction via the leaf spring.

JP 2011-255739 A

By the way, in the manufacturing process of the wiper blade provided with the vertebra as described above, it is necessary to keep the curved shape of the vertebra within a predetermined dimensional tolerance.
For this reason, the shape (curvature) of the manufactured vertebra is measured using a laser displacement meter or the like. Specifically, for example, the curvature of the vertebra is calculated by measuring the coordinates of the vertebra at a plurality of locations along the longitudinal direction where the vertebra is continuous, and differentiating the measurement result twice.
However, in the conventional method, the influence of noise generated during measurement by a laser displacement meter or the like is large, and it is difficult to manage the curved shape of the vertebra with high accuracy.

  Therefore, the present invention has been made in view of the above-described circumstances, and provides a shape evaluation method for a vertebra capable of suppressing the influence of noise during measurement and managing the curved shape of the vertebra with high accuracy. That is.

The present invention employs the following means in order to solve the above problems.
That is, the shape evaluation method of the vertebra of the present invention is a plate-like vertebra shape evaluation method for curving a blade rubber that is held by a blade holder that constitutes a wiper blade and wipes a window portion. A step of converting the acquired shape data into a displacement axis waveform, a step of performing a fast Fourier transform process on the displacement axis waveform to convert it into a spectrum waveform, and a predetermined from the spectrum waveform. A step of removing a component of order or higher, a step of converting the spectrum waveform from which the component has been removed by performing an inverse fast Fourier transform process to a displacement axis waveform, and a step of converting the spectrum waveform into a displacement axis waveform converted by an inverse fast Fourier transform process. And a step of evaluating the shape of the vertebra based on the shape data of the vertebra obtained based on And features.

  According to such a method, after converting the shape data of the vertebra into a displacement axis waveform, high-order components of a predetermined order or higher are removed from the spectrum waveform obtained through the fast Fourier transform process, thereby reducing noise. A removal process can be performed. The spectrum waveform after the noise removal process is returned to the displacement axis waveform by the inverse fast Fourier transform process, and the shape data of the vertebra can be obtained, so that the shape of the vertebra can be evaluated while the influence of noise is suppressed.

  Further, it is preferable that the curvature of the vertebra is calculated by differentiating the displacement axis waveform obtained by the inverse fast Fourier transform process twice, and the shape of the vertebra is evaluated based on the calculated curvature.

  According to such a method, the shape of the vertebra can be easily and reliably evaluated by differentiating the displacement axis waveform twice and calculating the curvature of the vertebra.

  According to the present invention, it is possible to suppress the influence of noise during measurement and to manage the curved shape of the vertebra with high accuracy.

It is a perspective view showing a part of vehicles equipped with a wiper blade provided with a vertebra in an embodiment of the present invention. It is a perspective view of a wiper blade in an embodiment of the present invention. It is a perspective view which shows the edge part of the wiper blade in embodiment of this invention in the state which removed the end cap. It is the perspective view which looked at the wiper blade in the embodiment of the present invention from the blade rubber side in the state where the end cap was removed. It is a perspective view which shows the blade rubber and the vertebra which comprise the wiper blade in embodiment of this invention. It is a figure which shows the flow of the shape evaluation method of the vertebra in embodiment of this invention. It is a figure which shows an example of the measurement result of the shape of the vertebra in embodiment of this invention. It is the figure which expanded the scale about a part of measurement result of the shape of the vertebra shown in FIG. An example of the spectrum waveform obtained by the fast Fourier transform in the embodiment of the present invention is shown. It is the figure which expanded the scale about a part of spectrum waveform shown in FIG. It is a figure which shows the example of the shape data of the vertebra obtained by the inverse fast Fourier-transform process in embodiment of this invention. It is a figure which shows the result of having differentiated twice the shape data of the vertebra in embodiment of this invention.

  Next, a vertebra shape evaluation method according to an embodiment of the present invention will be described with reference to the drawings.

(Wiper device)
FIG. 1 is a perspective view showing a part of a vehicle equipped with a wiper blade equipped with a vertebra in an embodiment of the present invention. FIG. 2 is a perspective view of the wiper blade. FIG. 3 is a perspective view showing the end of the wiper blade with the end cap removed. FIG. 4 is a perspective view of the wiper blade viewed obliquely from the blade rubber side with the end cap removed. FIG. 5 is a perspective view showing a blade rubber and a vertebra constituting the wiper blade.

As shown in FIG. 1, the wiper device 3 is provided on the window glass 2 of the vehicle 1 and secures the driver's view by wiping rain, dirt, and the like attached to the window glass 2.
The wiper device 3 includes, for example, two wiper arms 4 provided on the driver's seat side and the passenger seat side, and a wiper blade 10 attached to the tip of each wiper arm 4.

  Each wiper arm 4 has a base end fixed to the wiper shaft 5. The wiper shaft 5 is supported by the vehicle 1 so as to be rotatable around its central axis. Each wiper shaft 5 is connected to a wiper motor 7 fixed to the vehicle 1 via a link mechanism 6, and when the wiper motor 7 is operated, the two wiper shafts 5 and 5 are rotated in synchronization. The wiper arm 4 swings in a predetermined range integrally with the wiper shaft 5.

(Wiper blade)
The wiper blade 10 is provided so as to be pressed against the window glass 2 by the wiper arm 4. When the wiper arm 4 is swung by the wiper motor 7, the wiper blade 10 reciprocates in the wiping range 2 a on the outer surface of the window glass 2 to wipe the window glass 2.

  As shown in FIG. 2, the wiper blade 10 includes a blade holder 12 attached to the tip of the wiper arm 4 (see FIG. 1), a blade rubber 13 held by the blade holder 12, and a vertebra 14. ing. The wiper blade 10 has a longitudinal direction in a direction substantially orthogonal to the swinging direction of the wiper arm 4.

The blade holder 12 includes holder members 12B and 12B. The holder members 12 </ b> B and 12 </ b> B are made of, for example, a resin material and are provided on both sides in the longitudinal direction of the wiper blade 10 with respect to the clip portion 15 connected to the wiper arm 4.
As shown in FIGS. 3 and 4, each holder member 12 </ b> B includes a wiper rubber holding groove 12 a formed in the center portion in the width direction, and vertebra insertion portions 12 b and 12 b formed on both sides in the width direction. Yes. The wiper rubber holding groove 12a is continuous in the longitudinal direction of the wiper blade 10 and opens toward the window glass 2 side.
The vertebra inserters 12 b and 12 b have a cylindrical shape that is continuous in the longitudinal direction of the wiper blade 10.

  The blade rubber 13 is integrally provided with a head portion 13a, a lip portion 13b that contacts the window glass, and a connecting portion 13c that connects the head portion 13a and the lip portion 13b. The head portion 13a of the blade rubber 13 is inserted into the wiper rubber holding groove 12a formed in the holder members 12B and 12B, and holding claws 12t formed on both sides in the width direction of the wiper rubber holding groove 12a are formed in the head portion 13a. By engaging with the groove 13m formed, the blade rubber 13 is held by the holder members 12B and 12B.

As shown in FIGS. 3 to 5, the vertebra 14 is in the form of a leaf spring extending in the longitudinal direction of the wiper blade 10, and is disposed on both sides of the blade rubber 13 in the width direction.
As shown in FIGS. 3 and 4, each vertebra 14 is inserted into the vertebra insertion portion 12 b of the holder members 12 </ b> B and 12 </ b> B of the blade holder 12.

One holder member 12B and the other holder members 12B, 12B are arranged with a gap in the longitudinal direction of the wiper blade 10, and the blade rubber 13 and the vertebras 14, 14 are exposed in this gap.
The clip portion 15 is connected to the engagement metal fitting 16 (see FIG. 5) that engages with the vertebra 14, 14 exposed in the gap between the one holder member 12 </ b> B and the other holder member 12 </ b> B, 12 </ b> B. And a U-clip 19 (see FIG. 2) that is rotatably connected to the bracket 17 via a pin (not shown). The U-clip 19 of the clip portion 15 is detachably engaged with a hook portion (not shown) formed at the distal end portion of the wiper arm 4 so that the wiper blade 10 is attached to the wiper arm 4.

Further, the blade rubber 13 and the vertebras 14 and 14 protrude from the holder members 12B and 12B at both longitudinal ends of the wiper blade 10.
As shown in FIGS. 3 and 5, the blade rubber 13 protruding from the holder members 12 </ b> B and 12 </ b> B and the vertebrae 14 and 14 are connected by a joint clip 20 at both longitudinal ends of the wiper blade 10.
Further, the blade rubber 13, the vertebra 14, 14, and the joint clip 20 protruding from the holder members 12B, 12B are covered with end caps 21 shown in FIG. 2 at both ends in the longitudinal direction of the wiper blade 10.

  Further, the holder members 12B and 12B have a shape in which the wiper blade 10 is pressed against the window glass 2 side by the wind hitting the wiper blade 10 while the vehicle is mounted with the wiper blade 10 on the side opposite to the blade rubber 13 side. Fins 22 are integrally provided.

  In such a wiper blade 10, each vertebra 14 is curved with a predetermined curvature in a direction in which both end portions in the longitudinal direction protrude toward the window glass 2 with respect to the longitudinal center portion held by the clip portion 15. Yes. Due to the curvature of the vertebra 14, 14, the blade rubber 13 is also curved in the direction in which both ends in the longitudinal direction protrude toward the window glass 2 with respect to the central portion in the longitudinal direction.

(Vertebra shape evaluation method)
Next, a method for evaluating the shape of the vertebra constituting the wiper blade will be described.
FIG. 6 is a diagram showing a flow of the vertebra shape evaluation method in the present embodiment.
As shown in FIG. 6, the vertebra 14 constituting the wiper blade 10 is curved in the manufactured state. In order to evaluate the shape of the curved vertebra 14 as described above, first, the shape of the manufactured vertebra 14 is measured by using a laser displacement meter or the like at a plurality of locations along the longitudinal direction of the vertebra 14, for example, nine locations. (Step S101).

  7 and 8 show an example of the actual measurement result. Here, FIG. 7 is a diagram illustrating an example of an actual measurement result of the shape of the vertebra. FIG. 8 is an enlarged view of a part of the actual measurement result of the shape of the vertebra shown in FIG.

  Next, the obtained actual measurement data of the shape of the vertebra 14 is read as a displacement axis waveform (step S102).

Subsequently, the displaced displacement axis waveform is converted into a spectrum waveform by a fast Fourier transform process (FFT) (step S103).
FIG. 9 and FIG. 10 show examples of spectrum waveforms obtained by the fast Fourier transform process. As shown in FIG. 10, the spectrum waveform W1 based on the actual measurement data includes a lot of harmonic noise.

  Further, harmonic noise removal processing is performed on the converted spectrum waveform (step S104). Specifically, for example, components of 64th order or higher are removed.

Next, the spectrum waveform after the noise removal processing is subjected to inverse fast Fourier transform processing to return to the displacement axis waveform (step S105).
FIG. 11 shows an example of the shape data of the vertebra obtained by the inverse fast Fourier transform process. As shown in FIG. 11, the line L1 indicating the shape data of the vertebra 14 obtained by the above processing is smooth with noise removed.
On the other hand, the line L2 indicating the shape data of the vertebra 14 obtained by the conventional method without performing noise removal similar to that shown in FIG. 8 is disturbed by noise.

Thereafter, the curvature of the vertebra 14 is calculated by differentiating twice the shape data of the vertebra 14 obtained based on the obtained displacement axis waveform (step S106).
FIG. 12 shows the result of differentiating the vertebra shape data twice. As shown in FIG. 12, the result obtained by differentiating the shape data of the vertebra obtained by the processing of the present embodiment twice (symbol L11) shows the shape data of the vertebra obtained by the conventional method without performing noise processing. Compared to the case of differentiation twice (see reference numeral L12, broken line), the influence of noise is suppressed.
Thereafter, based on the calculated curvature of the vertebra 14, it is determined whether or not the vertebra 14 is within a predetermined curvature range, and the shape of the vertebra 14 is evaluated (step S107).

(effect)
Thus, according to the shape evaluation method of the vertebra 14 of this embodiment, after converting the shape data of the vertebra 14 into the displacement axis waveform, the spectrum waveform obtained through the fast Fourier transform process has a predetermined order or more. By removing higher-order components, noise removal processing can be performed. The spectrum waveform after the noise removal process is returned to the displacement axis waveform by the inverse fast Fourier transform process, and the shape data of the vertebra 14 is obtained, so that the shape of the vertebra 14 can be evaluated while suppressing the influence of noise. .

  Further, by calculating the curvature of the vertebra 14 by differentiating the displacement axis waveform obtained by the inverse fast Fourier transform process twice, the shape of the vertebra 14 can be easily and reliably evaluated.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention.

  For example, in the above embodiment, the configuration of the wiper blade 10 is shown. However, the configuration is only an example, and the wiper blade 10 may have any other configuration as long as it includes the vertebra 14.

Further, the wiper blade 10 is not limited to the window glass 2 provided at the front portion of the vehicle, but wipes a window portion including a window glass provided at the rear portion of the vehicle, a glass provided at another portion, a mirror, and the like. You may do.
In addition to this, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.

10 ... Wiper blade 12 ... Blade holder 13 ... Blade rubber 14 ... Vertebra

Claims (2)

A shape evaluation method for a plate-like vertebra that is held by a blade holder that constitutes a wiper blade and curves a blade rubber that wipes a window portion,
Obtaining the shape data of the vertebra;
Converting the acquired shape data into a displacement axis waveform;
A step of fast Fourier transforming the displacement axis waveform to convert it into a spectrum waveform; and
Removing a component of a predetermined order or more from the spectral waveform;
The spectral waveform from which the component has been removed is subjected to inverse fast Fourier transform processing and converted into a displacement axis waveform;
A step of evaluating the shape of the vertebra based on the shape data of the vertebra obtained based on the displacement axis waveform converted by the inverse fast Fourier transform process;
The shape evaluation method of the vertebra characterized by comprising.   The curvature of the vertebra is calculated by differentiating the displacement axis waveform obtained by the inverse fast Fourier transform process twice, and the shape of the vertebra is evaluated based on the calculated curvature. Item 2. A method for evaluating the shape of a vertebra according to Item 1.

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