JP4579720B2 - Antenna lifting device - Google Patents

Description

  The present invention relates to an antenna lifting device that lifts and lowers a measurement antenna that receives electromagnetic waves from an object to be measured along a vertically erected column. Specifically, the present invention relates to an antenna lifting device on the side of a column on the mounting side of the measurement antenna. The present invention relates to an antenna lifting device that reduces reflection or stabilizes the mounting posture of a measurement antenna to improve the measurement accuracy of radiation characteristics.

A conventional antenna elevating device is composed of a single column standing upright on the upper surface of a base, a slider that moves up and down along the single column, and a horizontal support on the slider to measure at the tip. An antenna support rod for mounting a measurement antenna that receives electromagnetic waves from an object, and a drive unit that transmits power to the slider via a belt to raise and lower the slider (see, for example, Patent Document 1).
No. 5-45981

  However, in such a conventional antenna lifting apparatus, the support column is a columnar body having a quadrangular cross-sectional shape, and is installed so that one side surface of the quadrangular columnar body faces the arrival direction of the electromagnetic wave. Therefore, electromagnetic waves reflected on the side surfaces, particularly short wavelength electromagnetic waves, are reflected on the mounting side of the measurement antenna and many of them are received by the measurement antenna, which may deteriorate the measurement accuracy.

  In addition, since the antenna support bar is supported by a slider with respect to a single column, when the measurement antenna is attached to the tip of a long antenna support bar, the tip is bent and the measurement antenna is tilted. The measurement accuracy of the radiation characteristics of the electromagnetic waves radiated from the object to be measured may be deteriorated.

  Therefore, the present invention addresses such problems, reduces the reflection of electromagnetic waves from the object to be measured on the side of the column to the mounting side of the measuring antenna, or stabilizes the mounting posture of the measuring antenna. An object of the present invention is to provide an antenna lifting device that improves the measurement accuracy of the radiation characteristics of electromagnetic waves.

  In order to achieve the above object, an antenna lifting apparatus according to a first aspect of the present invention includes a column that is erected perpendicularly to the upper surface of a base, a slider that is vertically movable along the column, and the slider that includes the slider. Lifting means for raising and lowering along the support, an antenna support bar horizontally supported by the slider and capable of attaching a measurement antenna for receiving electromagnetic waves from the object to be measured to the tip, and the lifting means A drive unit that drives by applying a driving force, and the support column has a shape in which a plurality of elongated plate-like structural members extend vertically across the plate surface, and the measurement antenna on the side surface thereof The constituent members are arranged so that the reflection of electromagnetic waves to the mounting side is reduced.

  With such a configuration, a plurality of elongated plate-shaped components are vertically extended on the upper surface of the base, and have a shape extending vertically across the plate surface. The slider is supported by a column with the above components so that the reflection of electromagnetic waves on the slider can be moved up and down, and the antenna support bar that can attach the measurement antenna to the tip is horizontally supported by the slider. The driving unit applies a driving force to the lifting means to move the slider up and down, and the measuring antenna is lifted and received by the measuring antenna.

  Further, the second invention of the antenna lifting apparatus includes two struts that are vertically erected on the upper surface of the base at a predetermined interval and a pair that is vertically movable along the two struts. Sliders, lifting and lowering means for moving the pair of sliders up and down synchronously along the two struts, supported by the pair of sliders and horizontally spanned over the two struts, and covered at the tip portion. An antenna support rod that can be attached with a measurement antenna that receives electromagnetic waves from a measurement object, and a drive unit that is driven by applying a driving force to the elevating means, and at least electromagnetic waves of the two columns. The front support column in the direction of arrival has a shape in which a plurality of elongated plate-like components extend vertically across the plate surface, and reflection of electromagnetic waves on the side of the measurement antenna on the side surface is reduced. The components are arranged as shown in FIG. One in which the.

  With such a configuration, among the two pillars standing upright at a predetermined interval on the upper surface of the base, at least in front of the arrival direction of the electromagnetic wave, a plurality of elongated plate-like components are arranged on the plate. Reflecting electromagnetic waves to the mounting side of the measurement antenna on the side of the column with a shape extending vertically across the surface, and supporting the pair of sliders up and down with the two columns, A pair of sliders support an antenna support rod that can be attached to the measurement antenna at the tip, and are horizontally routed on the two struts. The drive unit applies a driving force to the lifting means, and the pair of sliders. Is moved up and down, and the measurement antenna is moved up and down to receive the electromagnetic wave from the object to be measured by the measurement antenna.

  Further, the support column has a substantially cross-shaped shape, a substantially T-shaped shape or a substantially L-shaped cross-sectional shape, and the plate surface of one constituent member is matched with the arrival direction of the electromagnetic wave. As a result, the cross-sectional shape has a substantially cross shape, a substantially T-shape or a substantially L-shape, and the slider can be moved up and down by a column having the plate surface of one component matched with the arrival direction of the electromagnetic wave.

  Furthermore, an electromagnetic wave absorber is provided on the surface on the electromagnetic wave arrival direction side of the other constituent members of the support column. Thus, the electromagnetic wave is absorbed by the electromagnetic wave absorber provided on the surface on the electromagnetic wave arrival direction side of the other constituent members of the column.

  And the said support | pillar has a cross-sectional shape substantially cross shape, substantially T shape, or substantially L shape, and inclines the plate | board surface of each structural member by predetermined angle with respect to the electromagnetic wave arrival direction, respectively. As a result, the cross-sectional shape has a substantially cross shape, a substantially T-shape or a substantially L-shape, and the slider can be moved up and down by a column whose plate surface is inclined by a predetermined angle with respect to the electromagnetic wave arrival direction. To do.

  According to the first aspect of the present invention, the support column that is erected perpendicularly to the upper surface of the base has a shape in which a plurality of elongated plate-like components extend vertically across the plate surface, and the side surfaces thereof. By arranging the constituent members so as to reduce the reflection of the electromagnetic wave on the mounting side of the measurement antenna in the electromagnetic wave, the electromagnetic wave reflected by the side surface of the support and received by the measurement antenna can be reduced. Accordingly, it is possible to improve the measurement accuracy of the radiation characteristics of the electromagnetic wave from the object to be measured.

  Further, according to the invention of claim 2, at least one of the two struts standing upright at a predetermined interval on the upper surface of the base and vertically in front of the electromagnetic wave arrival direction has a plurality of elongated plate-like shapes. The component member has a shape extending vertically across the plate surface, and the component member is disposed so that reflection of the electromagnetic wave to the mounting side of the measurement antenna on the side surface is reduced. It is possible to reduce electromagnetic waves that are reflected by the side surface of the support column ahead of the arrival direction and received by the measurement antenna. Accordingly, it is possible to improve the measurement accuracy of the radiation characteristics of the electromagnetic wave from the object to be measured. Further, a pair of sliders are supported by two columns so that the slider can move up and down, and an antenna support bar on which the measurement antenna can be attached to the tip is supported by the pair of sliders and is horizontally hung on the two columns. By passing the antenna, the bending of the antenna support rod can be reduced, and the mounting posture of the measurement antenna can be stabilized. Therefore, the measurement accuracy of the radiation characteristic of the electromagnetic wave from the object to be measured can be further improved.

  According to the invention of claim 3, the column has a substantially cross-shaped or substantially T-shaped or substantially L-shaped cross section, and the plate surface of one constituent member is matched with the arrival direction of the electromagnetic wave. Thereby, the influence of the reflection of the electromagnetic wave from the object to be measured by the support can be reduced.

  Furthermore, according to the invention of claim 4, by providing an electromagnetic wave absorber on the electromagnetic wave arrival direction side surface of the other constituent members of the column, the electromagnetic wave from the object to be measured is absorbed by the radio wave absorber and the column. The influence of reflection due to can be further reduced.

  According to the fifth aspect of the present invention, the column has a substantially cross-shaped or substantially T-shaped or substantially L-shaped cross section, and the plate surface of one component member is predetermined with respect to the electromagnetic wave arrival direction. By tilting only the angle, it is possible to further reduce the influence of the reflection of the electromagnetic wave from the object to be measured by the column.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 is a front view showing an embodiment of an antenna lifting apparatus according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a right side view of FIG. This antenna elevating device is for elevating by attaching a measurement antenna 28 for receiving electromagnetic waves from a device under test 1 such as a transmission antenna, various communication devices or various electronic devices, and has a base 2 and two struts. 3a, 3b, a pair of sliders 4a, 4b, an elevating means 5, an antenna support bar 6, and a drive unit 7.

  The base 2 holds the below-mentioned support pillars 3a and 3b upright on a flat upper surface and installs the drive unit 7. For example, a plate of a non-metallic material such as reinforced plastic (FRP) or vinyl chloride The base member 8 and the sub-base member 9 are formed.

  The base member 8 is made of a plate material formed in a rectangular shape, and can be moved by providing casters 10 at the four corners on the back surface thereof. In the vicinity of the caster 10, an adjuster foot 11 is provided by being screwed into a screw hole penetrating in the vertical direction, and the height of the adjuster foot 11 is adjusted to make the base member 8 horizontal. Can be kept.

  A rectangular sub-base member 9 is provided on the upper surface of the base member 8. This sub-base member 9 stands upright the support columns 3a and 3b and installs the drive unit 7. As shown in FIG. 3, the sub-base member 9 is placed horizontally at both ends of one side with respect to the base member 8. The shaft 12 is rotatably supported in the direction of arrow A. A plurality of through holes are provided on the peripheral side of the sub base member 9, and the fixing screws 13 are screwed into the screw holes provided in the base member 8 through the through holes as shown in FIG. It can be fixed together.

  As shown in FIG. 1, two support columns 3 a and 3 b are provided on the upper surface of the sub-base member 9 so as to stand upright at a predetermined interval. The two columns 3a and 3b hold a pair of sliders 4a and 4b, which will be described later, so as to be movable up and down, and as shown in FIG. 4, a plurality of elongated plate-like components 14a, 15a or 14b, 15b has a shape extending vertically across its plate surface, and its cross-sectional shape is substantially cross-shaped, and is made of a non-metallic material such as FRP. Further, as shown in FIG. 1, reinforcing members 16a and 16b are provided at the lower ends of the support columns 3a and 3b, respectively, and the installation area is expanded to ensure installation stability. Further, a head member 17 is provided at the upper end of each of the columns 3a and 3b so as to span the columns 3a and 3b so that the parallel state of the columns 3a and 3b can be maintained. As shown in FIG. 3, the support columns 3a and 3b are laid down in the direction of arrow A around the shaft 12 that pivotally supports the sub-base member 9 at the time of transport, so that the transport is facilitated. ing.

  Here, the support column 3a positioned in front of at least the direction of arrival of electromagnetic waves from the DUT 1 (the direction of arrow B in FIG. 1) is the mounting side of the measurement antenna 28 on the side surface thereof as shown in FIG. The plate surfaces of the constituent members 14a and 15a are arranged so as to be inclined at a predetermined angle, for example, ± 45 degrees, with respect to the electromagnetic wave arrival direction (arrow B direction) so that the reflection of the electromagnetic wave to the surface is reduced.

  A pair of sliders 4a and 4b is provided on the two support columns 3a and 3b. The pair of sliders 4a and 4b move up and down along the two columns 3a and 3b, and are formed of a non-metallic material such as FRP, for example, as shown in FIG. 5A for the slider 4a. And a second insertion hole 19 which is provided on the side of the first insertion hole 18 and penetrates in the horizontal direction as shown in FIG. ing. The same applies to the slider 4b. In the following description, the slider 4a will be described.

  The first insertion hole 18 is for inserting the support column 3a, and as shown in FIG. 5A, the two structures of the support column 3a intersecting each other and having a substantially cross-shaped cross section. Rollers 20 are provided at positions corresponding to the end portions of the members 14a and 15a so that the slider 4a can smoothly move up and down along the column 3a. The second insertion hole 19 is for inserting and supporting an antenna support bar 6 to be described later, and as shown in FIG. It is formed in a regular octagonal star shape so that it can be rotated and installed.

  Elevating means 5 is provided between the driving unit 7 and the pair of sliders 4a and 4b. The elevating means 5 is provided with a driving force by the driving unit 7 to elevate and lower the pair of sliders 4a and 4b along the two struts 3a and 3b, as shown in FIG. Drive gears 21a and 21b, driven gears 22a and 22b, first timing pulleys 23a and 23b, second timing pulleys 24a and 24b (see FIG. 1), and timing belts 25a and 25b (see FIG. 1) Consists of. In addition, all the said raising / lowering means 5 is formed with the nonmetallic material.

  The drive gears 21a and 21b are respectively provided in the vicinity of the lower ends of the two support columns 3a and 3b on the connecting shaft 26 connected to the rotation shaft of the drive unit 7, and It rotates with the rotation. The driven gears 22a and 22b mesh with the drive gears 21a and 21b, respectively, and rotate. Further, the first timing pulleys 23a and 23b are provided with respect to the shafts of the driven gears 22a and 22b and rotate together therewith. The second timing pulleys 24a and 24b are provided in the vicinity of both ends of the head member 17 shown in FIG. 1 corresponding to the first timing pulleys 23a and 23b. Further, as shown in FIG. 1, the timing belts 25a and 25b are wound around the first timing pulleys 23a and 23b and the second timing pulleys 24a and 24b, and one end portions thereof are the upper end portions of the sliders 4a and 4b. The other end is fixed to the lower end of each of the sliders 4a and 4b, so that the rotational force of the rotating shaft of the drive unit 7 can be converted into the linear motion of the sliders 4a and 4b in the vertical direction. ing.

  Further, the rotation shafts of the driven gears 22a and 22b are provided with encoders 26a and 26b, respectively, and the heights of the elevating members 4a and 4b can be measured by detecting the rotation speed and rotation angle of the driven gears 22a and 22b. Yes. Furthermore, the drive gear 21a is provided with a brake 27 so that the rotation of the drive gear 21a can be braked. Thereby, the sliders 4a and 4b can be quickly stopped at predetermined positions, and the setting accuracy of the height of the measurement antenna 28 (see FIG. 1) can be improved.

  As shown in FIG. 1, an antenna support bar 6 is supported on the pair of sliders 4a and 4b. The antenna support bar 6 is horizontally stretched over the two support columns 3a and 3b, and is provided with an antenna mounting portion 29 at its tip so that the measurement antenna 28 can be mounted. It is made of a non-metallic material and has a rectangular cross-sectional shape. In this case, if one of the corners is installed in the vertical direction, the reflection direction of the electromagnetic wave on the upper and lower surfaces is different from the mounting side of the measurement antenna 28, and the electromagnetic wave is emitted from the measurement antenna 28. The measurement accuracy of characteristics can be further improved. At the rear end portion, a cable guide 30 is provided, and an RF cable for connecting the measurement antenna 28 and a measuring device (not shown) is gently bent along a guide rail formed in an arc shape. It prevents the core wire from being bent and cut, and the impedance from becoming high.

  On the upper surface of the sub-base member 9, a drive unit 7 is installed in the vicinity of the support column 3b behind the electromagnetic wave arrival direction (arrow B direction). The drive unit 7 is driven by applying a driving force to the elevating means 5 to move the sliders 4a and 4b up and down, and is a motor, for example.

Next, the operation of the antenna lifting apparatus configured as described above will be described.
First, as shown in FIG. 3, the sub-base member 9 is rotated about the shaft 12 in the direction opposite to the arrow A to erect the two columns 3a and 3b. Then, a fixing screw 13 is screwed into a screw hole provided in the base member 8 through a plurality of through holes provided in the periphery of the sub base member 9, thereby fixing the sub base member 9 to the base member 8.

  Further, if necessary, a rope is stretched between both ends of the head member 17 of the columns 3a and 3b and the four corners of the base member 8, and the tension of the ropes is adjusted to raise the postures of the two columns 3a and 3b. Adjust so that it is perpendicular to the installation surface. Further, when installed outdoors, pegs are driven into the ground on the sides of the four corners of the base member 8, and ropes are stretched between the pegs and both ends of the head member 17 to prevent the base member 8 from falling.

  Next, as shown in FIG. 5, the antenna support bar 6 is installed through the second insertion holes 19 of the sliders 4a and 4b, and the antenna attachment at the tip of the antenna support bar 6 is installed as shown in FIG. A measurement antenna 28 is attached to the portion 29. Further, an RF cable (not shown) that hangs down through the cable guide 30 at the rear end of the antenna support bar 6 is connected to the measuring instrument.

  Next, the driving unit 7 is driven to apply a driving force to the lifting / lowering means 5, and the two sliders 4 a and 4 b are raised to a predetermined position by the lifting / lowering means 5. Then, the measurement antenna 28 is installed at a predetermined height. At this time, since the two sliders 4a and 4b are driven synchronously by the elevating means 5, the antenna support bar 6 moves smoothly while maintaining a horizontal state.

  When the measurement antenna 28 is installed at a predetermined height, the DUT 1 placed opposite to the measurement antenna 28 by a predetermined distance is driven, and electromagnetic waves are emitted from the DUT 1. Radiated. The measurement antenna 28 receives this electromagnetic wave and measures the radiation characteristic of the electromagnetic wave of the DUT 1. In this case, of the two struts 3a and 3b, at least the strut 3a in front of the direction of arrival of electromagnetic waves (the direction of arrow B in FIG. 1) passes the plate surfaces of the two component members 14a and 15a orthogonal to each other. (Direction B) are inclined by ± 45 degrees (see FIG. 4), so that the electromagnetic wave reflected from the side surface of the electromagnetic wave support 3a, particularly the short wavelength electromagnetic wave having a wavelength of about 2.4 GHz, for example, is reflected. The coefficient is reduced, and the reflection of electromagnetic waves to the mounting side of the measurement antenna 28 on the side surface of the column 3a is reduced, so that the measurement accuracy of the radiation characteristics is improved.

  And when measuring electromagnetic waves of different polarization planes, the antenna support rod 6 is rotated by a predetermined angle to switch the polarization planes. The polarization plane may be switched by removing the antenna support bar 6 once, changing the angle, and installing it again. However, the antenna support bar 6 can be rotated in the second insertion hole 19 of the sliders 4a and 4b. A rotating mechanism that supports the rotating mechanism may be provided, and the rotating force of the driving unit 7 may be transmitted to the rotating mechanism to rotate the antenna support rod 6. In this case, the polarization plane switching means disclosed in Japanese Utility Model Publication No. 5-45981 can be applied.

  Here, as shown in FIG. 4, in the first embodiment, the plate surfaces of the two component members 14a and 15a orthogonal to each other are inclined by ± 45 degrees with respect to the electromagnetic wave arrival direction (arrow B direction). An example in which the reflection coefficient of the electromagnetic wave having a frequency of 2.4 GHz was measured by the spatial standing wave method for the support 3a was about 0.2 as shown in FIG. This is sufficiently smaller than about 0.56 of the conventional example in which one side surface of a column having a square cross section is set to face the electromagnetic wave arrival direction (arrow B direction). Indicates that reflection has been reduced.

  FIG. 8 is a cross-sectional view showing a second embodiment of the column 3a. The column 3a of the second embodiment is installed by aligning the plate surface of one component member 14a of the two component members 14a and 15a orthogonal to each other in the direction of arrival of electromagnetic waves (arrow B direction). Yes. In such a column 3a, the reflection coefficient of the electromagnetic wave was about 0.29 in comparison with the conventional example, as shown in FIG.

  FIG. 9 is a view showing a third embodiment of the support post 3a. The column 3a according to the third embodiment is installed with the plate surface of one of the two component members 14a and 15a orthogonal to each other aligned with the arrival direction of the electromagnetic wave (arrow B direction). A square pyramid electromagnetic wave absorber 31, for example, graphite powder mixed with urethane foam is provided on the surface of the other component member 15a on the electromagnetic wave arrival direction (arrow B direction) side. In such a column 3a, the reflection coefficient of the electromagnetic wave is about 0.04 in comparison with the conventional example as shown in FIG. 7, which is much smaller than the conventional example.

  In the above-described embodiment, both the two columns 3a and 3b have a substantially cross-shaped cross section. However, the present invention is not limited to this, and only the column 3a in front of the arrival direction of electromagnetic waves has a cross-sectional shape. It may be a substantially cross shape.

  Of the support pillars 3a and 3b, at least the support pillar 3a in front of the direction of arrival of electromagnetic waves is not limited to one having a substantially cross-sectional cross shape, and the cross-sectional shape is substantially T-shaped or L-shaped. It may be a thing. Alternatively, any shape may be used as long as a plurality of plate-shaped constituent members intersect and have a shape extending vertically. In any of the above cases, it is necessary to arrange the constituent members so that the reflection of the electromagnetic wave on the side surface of the support to the mounting side of the antenna for measurement 28 is reduced.

  Furthermore, although the case where the two support | pillars 3a and 3b were provided was demonstrated in the said embodiment, it is not restricted to this, You may provide only the support | pillar 3a of the front side of the electromagnetic wave arrival direction.

  And in the said embodiment, although the case where the antenna support rod 6 had a square cross-sectional shape was demonstrated, it is not restricted to this, A cross-sectional shape may be circular, or the reflection direction of the electromagnetic waves in the side surface is Any shape may be used as long as the direction is different from the mounting side of the measurement antenna 28. Furthermore, the antenna support rod 6 may have a shape in which a plurality of plate-shaped constituent members intersect and extend vertically. Also in this case, it is necessary to arrange the above-mentioned constituent members so that the reflection of the electromagnetic wave on the side surface of the antenna support bar 6 to the mounting side of the measurement antenna 28 is reduced.

It is a front view which shows embodiment of the antenna raising / lowering apparatus by this invention. It is a top view of FIG. It is a right view of FIG. In the said antenna lifting / lowering apparatus, it is a cross-sectional view which shows the shape of a support | pillar. In the said antenna raising / lowering apparatus, it is a figure which shows one structural example of a slider, (a) is a top view, (b) is a right view. In the said antenna raising / lowering apparatus, it is explanatory drawing which shows the principal part of a drive part and the raising / lowering means connected to it. It is a table | surface which shows the experimental result which changed the shape and installation state of the said support | pillar, and measured the reflection coefficient of electromagnetic waves. It is a cross-sectional view which shows the 2nd Example of the said support | pillar. It is a figure which shows the 3rd Example of the said support | pillar, (a) is a cross-sectional view, (b) is a principal part expansion right view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... To-be-measured object 2 ... Base 3a, 3b ... Column 4a, 4b ... Slider 5 ... Lifting means 6 ... Antenna support bar 7 ... Drive part 14a, 14b, 15a, 15b ... Constituent member 28 ... Measuring antenna 31 ... Electromagnetic wave Absorber B ... Direction of arrival of electromagnetic wave

Claims (5)

A column that stands upright on the top surface of the base;
A slider provided to be movable up and down along the column;
Elevating means for elevating the slider along the column;
An antenna support bar that is horizontally supported by the slider and that can be attached with a measurement antenna that receives electromagnetic waves from the object to be measured at the tip,
A driving unit that drives the lifting means by applying a driving force;
The support column has a shape in which a plurality of elongated plate-like structural members extend vertically across the plate surface so that reflection of electromagnetic waves to the mounting side of the measurement antenna on the side surface is reduced. An antenna elevating device, wherein the constituent members are arranged. Two struts erected vertically at a predetermined interval on the upper surface of the base;
A pair of sliders provided so as to be movable up and down along the two columns;
Elevating means for elevating and lowering the pair of sliders along the two columns;
An antenna support bar supported by the pair of sliders and horizontally spanned over the two columns, and capable of attaching a measurement antenna for receiving electromagnetic waves from the object to be measured at the tip,
A driving unit that drives the lifting means by applying a driving force;
Of the two struts, at least the front strut in the direction of arrival of electromagnetic waves has a shape in which a plurality of elongated plate-shaped constituent members extend vertically across the plate surface, and the measurement antenna on the side surface thereof An antenna elevating device, wherein the constituent members are arranged so as to reduce reflection of electromagnetic waves to the mounting side of the antenna.   The said support | pillar has cross-sectional shape substantially cross shape, substantially T shape, or substantially L shape, and made the plate | board surface of the one structural member correspond to the arrival direction of electromagnetic waves, or 1 or 2 characterized by the above-mentioned. Antenna lifting device.   The antenna lifting / lowering apparatus according to claim 3, wherein an electromagnetic wave absorber is provided on a surface on the electromagnetic wave arrival direction side of another constituent member of the support column.   The said support | pillar has cross-sectional shape substantially cross shape, substantially T shape, or substantially L shape, and inclined the plate | board surface of each structural member by predetermined angle with respect to the electromagnetic wave arrival direction, respectively. The antenna lifting apparatus according to 1 or 2.

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