Equatorial sundial and manufacturing method thereof

Abstract

The invention provides an equatorial sundial and a manufacturing method thereof. The equatorial sundial comprises a latitude plate, a dial face fixing plate, a sundial disk, and an hour difference quick-checking ruler. The dial face fixing plate is formed by folding the front side of the dial face fixing plate and the back side of the dial face fixing plate in half. The front side of the dial face fixing plate is provided with a geographic longitude scale. The dial face fixing plate is fixed to one side of two latitude plates. The sundial disk is clamped between the front side and the back side of the dial face fixing plate. A style is provided at the center of the sundial disk. Time scales are provided on the front and back sides of the sundial disk. A geographic longitude alignment line, a date scale, and a true mean time difference value diagram corresponding to the date scale are also provided on the front side of the sundial disk. The geographic longitude alignment line is aligned with the geographic longitude of an observation site corresponding to the geographic longitude scale. One end of the hour difference quick-checking ruler is provided with a first positioning hole capable of being positioned on the style. The hour difference quick-checking ruler is provided with an hour difference scale. The present invention can be widely applied in different places, is convenient for measuring time difference, and is easy to manufacture.

Description

Technical Field

[0001] The present invention relates to the technical field of sundials, and in particular to an equatorial sundial and a manufacturing method thereof. Background Art

[0002] A sundial, also known as a sundial, is a device that specifies the hour or minute based on the position of the sun's shadow.

[0003] The equatorial sundial is one of the most classic and traditional astronomical instruments of ancient China. It typically consists of a base, a pointer, and a disk. The pointer is called the "style," with its upper end pointing toward the north celestial pole and its lower end toward the south celestial pole. The angle between the style and the ground (horizontal plane) is the local latitude. The disk is called the "dial plate," and its inclination angle to the horizontal plane is 90° - Φ (where Φ is the local latitude). Its main characteristic is that the hour markings on the dial are equally spaced.

[0004] The time displayed on an equatorial sundial is similar to that of a modern clock. The time scale is evenly spaced across the dial, and the time can be read directly by looking at the direction of the gnomon's shadow. However, this displayed time is the sundial time, the true solar time at the location where the sundial is installed, not the time we use in daily life.

[0005] The time we use now is "Beijing Time", which is the mean solar time at 120 degrees east longitude. There are two values ​​that need to be converted between sundial time and Beijing time: the "longitude time difference" and the "true mean solar time difference".

[0006] There are many educational tools available in China related to equatorial sundials, most of which are devices that adjust the latitude to suit the local geographic latitude. The distinctions between "longitude time difference" and "true mean solar time difference" require instruction in textbooks or by a lecturer. Summary of the Invention

[0007] In view of the defects in the prior art, the present invention provides an equatorial sundial and a manufacturing method thereof, which can be widely used in different locations, is convenient for measuring time differences and is easy to manufacture.

[0008] In one aspect, the present invention provides an equatorial sundial comprising:

[0009] Latitude plate, the latitude plate having two sides, the angle between the two sides = 90° - the geographical latitude of the observation site, and two latitude plates are provided on the left and right sides;

[0010] A dial plate, the dial plate being formed by folding the front and back of the dial plate in half, the front and back of the dial plate both having concave arc edges on the sides away from the folding line, the front of the dial plate having geographic longitude scales along the arc edges, the dial plate being fixed to one side of the two latitude plates, with the concave arc edges of the dial plate facing obliquely upwards;

[0011] A sundial plate, the sundial plate being clamped between the front and back surfaces of the dial face fixing plate, the sundial plate being concentric with the center of the concave arc edge, a style being provided at the center of the sundial plate and extending through both sides, the sundial plate being provided with time scales on both the front and back surfaces, the front surface of the sundial plate also being provided with a geographic longitude alignment line, a date scale, and a true mean time difference diagram corresponding to the date scale, the geographic longitude alignment line being aligned with the geographic longitude of the observation location corresponding to the geographic longitude scale;

[0012] A time difference speed-checking ruler is provided with a first positioning hole at one end thereof which can be positioned on a sundial, and a time difference scale extending from the first positioning hole toward a distal end thereof.

[0013] Furthermore, the latitude plate is made of a right-angled sector plate, on which a geographic latitude scale is provided, and the central angle of the latitude plate actually required to be used is cut according to the geographic latitude of the observation site.

[0014] Furthermore, it also includes a positioning lining, which is clamped between the front and back sides of the dial face fixing plate. One side of the positioning lining is provided with a positioning arc edge that matches the arc edge of the sundial disk.

[0015] Furthermore, a first snap-fitting protrusion is provided on one side edge of the latitude plate, and first snap-fitting grooves are provided on the front face of the dial fixing plate, the back face of the dial fixing plate and both ends of the positioning lining. The first snap-fitting grooves on the front face of the dial fixing plate, the back face of the dial fixing plate and the positioning lining are aligned and overlapped respectively, and each first snap-fitting protrusion is respectively snapped into a corresponding overlapping first snap-fitting groove on the front face of the dial fixing plate, the back face of the dial fixing plate and the positioning lining.

[0016] Furthermore, the latitude plate is provided with a first bayonet, and the first bayonet extends from a side close to a low-latitude geographic latitude scale;

[0017] It also includes a latitude support plate, and a second bayonet is provided on one side of the latitude support plate close to both ends. The second bayonet at both ends of the latitude support plate respectively corresponds to the first bayonet on the two latitude plates and is engaged with each other.

[0018] Furthermore, the latitude support plate is provided with strip grooves near both ends, and the latitude support plate is folded along the center line so that the strip grooves at both ends of the latitude support plate form a second bayonet on one side of the latitude support plate.

[0019] Furthermore, the gnomon passes through the center of the sundial plate, and the gnomon is provided with a front fixing plate positioned on the front of the sundial plate and a rear fixing plate positioned on the back of the sundial plate.

[0020] Furthermore, it also includes a solar term scale, which includes a solar term scale positioning plate and a solar term scale scale plate. The solar term scale positioning plate and the solar term scale scale plate form a vertical L-shaped structure. The solar term scale positioning plate is provided with a second positioning hole capable of being positioned on the sundial at one end away from the solar term scale scale plate, and the solar term scale is provided on a side of the solar term scale plate close to the solar term scale positioning plate.

[0021] Furthermore, the solar term scale also includes two solar term scale support plates, the solar term scale support plates have two vertical side edges, and second clamping protrusions are provided on the two vertical side edges of the solar term scale support plates. Second clamping grooves are provided on both sides of the solar term scale positioning plate and the solar term scale scale plate, and the second clamping protrusions on both sides of each of the solar term scale support plates correspond one-to-one to the second clamping slots on the solar term scale positioning plate and the solar term scale plate.

[0022] In another aspect, the present invention provides a method for manufacturing an equatorial sundial, comprising the following steps:

[0023] Step S10: remove two rectangular sector-shaped latitude plates marked with geographic latitude scales from the printed cardboard, and cut the latitude plates according to the geographic latitude of the observation site, so that the geographic latitude scale values ​​of the cut latitude plates are the geographic latitude of the observation site;

[0024] Step S20: Remove the dial plate front, dial plate back, and positioning lining of the dial plate from the printed paperboard, fold the dial plate front and dial plate back along the middle dotted line, and install the positioning lining between the folded dial plate front and dial plate back.

[0025] Step S30, assembling the two cut latitude plates on the back sides of both ends of the sundial fixed plate respectively;

[0026] Step S40, removing the sundial plate printed with the front and back patterns from the printed cardboard, and folding the front and back of the sundial plate in half;

[0027] Step S50, passing the gnomon through the center of the sundial plate, and inserting the front fixing plate and the rear fixing plate from both ends of the gnomon respectively to fix them on both sides of the sundial plate;

[0028] Step S60: insert the sundial plate between the front and back surfaces of the dial face fixing plate, and rotate the sundial plate so that the geographic longitude alignment line on the sundial plate is aligned with the geographic longitude of the observation site corresponding to the geographic longitude scale.

[0029] The beneficial effects of the present invention are embodied in:

[0030] 1. When using a sundial, the sundial plate can be rotated to align the geographic longitude alignment line on the sundial plate with the geographic longitude of the observation location corresponding to the geographic longitude scale on the dial plate, thereby correcting the sundial plate according to the geographic longitude of the observation location to achieve the purpose of correcting the longitude time difference. At the same time, the time difference value can be quickly checked on the sundial plate using a time difference speed checker. The method of checking is as follows: the first positioning hole on the time difference speed checker is positioned on the gnomon, and then the time difference speed checker is rotated so that the time difference speed checker is aligned with the observation date corresponding to the date scale, and then the reading at the intersection of the time difference speed checker and the true time difference diagram is read, which is the time difference value. The sundial time can be directly read from the time scale indicated by the shadow of the gnomon on the sundial plate, and then Beijing time can be calculated as sundial time + time difference value. Therefore, the present application can be widely applied in different locations, is convenient for measuring time difference, and is convenient for quickly converting sundial time into Beijing time.

[0031] 2. The components required for the equatorial sundial are integrated on cardboard by die-stamping. All parts can be removed from the cardboard by simple cutting and then assembled according to the design. The sundial needle can be used as a toothpick. Its structure is simple and users can assemble it by themselves, making it easy to make. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0033] Figure 1 This is a schematic diagram of a paperboard according to a first embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of another paperboard according to an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of a cutout of a latitude plate according to an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of the assembly of the positioning liner and the dial fixing plate according to an embodiment of the present invention;

[0037] Figure 5 A front view of the assembly of the positioning liner and the dial face fixing plate according to an embodiment of the present invention;

[0038] Figure 6 Schematic diagram of the assembly of the dial fixing plate and the latitude plate according to an embodiment of the present invention;

[0039] Figure 7 A front view of the assembly of the sundial plate and the dial face fixing plate according to an embodiment of the present invention;

[0040] Figure 8 A schematic diagram of reading time difference values ​​according to an embodiment of the present invention;

[0041] Figure 9 This is a partial enlarged view of reading the time difference value according to an embodiment of the present invention;

[0042] Figure 10 This is a schematic structural diagram of a solar term scale according to an embodiment of the present invention;

[0043] Figure 11 Schematic diagram of the assembly of the solar term scale and the sundial plate according to an embodiment of the present invention;

[0044] Figure 12 This is a schematic diagram of reading solar terms according to an embodiment of the present invention.

[0045] In the accompanying drawings, 100-latitude plate; 110-geographic latitude scale; 120-first engaging protrusion; 130-first engaging hole; 200-dial plate; 210-front of dial plate; 220-back of dial plate; 230-inward arc edge; 240-geographic longitude scale; 250-first engaging groove; 300-sundial plate; 310-dial style; 311-front fixing plate; 312-rear fixing plate; 320-time scale; 330-geographic longitude alignment line; 340- Date scale; 350-True time difference chart; 400-Time difference quick-check ruler; 410-First positioning hole; 420-Time difference scale; 500-Positioning lining; 510-Positioning arc edge; 600-Latitude support plate; 610-Strip groove; 700-Solar term scale; 710-Solar term scale positioning plate; 711-Second positioning hole; 720-Solar term scale plate; 721-Solar term scale; 730-Solar term scale support plate; 731-Second snap-in protrusion; 732-Second snap-in slot. DETAILED DESCRIPTION

[0046] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0047] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0048] The embodiment of the present invention provides an equatorial sundial, such as Figure 1 and Figure 2 As shown, the parts required for the equatorial sundial are integrated on the cardboard by die-printing.

[0049] Reference Figure 3-Figure 9The equatorial sundial includes a latitude plate 100, a dial fixing plate 200, a sundial plate 300 and an time difference quick-checking ruler 400.

[0050] The latitude plate 100 has two sides, and the angle between the two sides is 90°-the geographical latitude of the observation location. Two latitude plates 100 are provided on the left and right sides.

[0051] Reference Figure 3 The latitude plate 100 is made of a right-angled sector plate, on which a geographic latitude scale 110 is provided. The central angle of the latitude plate 100 is cut according to the geographic latitude of the observation site. For example, if the geographic latitude of the observation site is 30 degrees, then refer to Figure 3 , use the angle values ​​of the right angle tip and the inner and outer rings as reference, draw lines with the help of a ruler and then cut with a knife or scissors. The values ​​cut off from the two latitude plates at 100 should be the local geographical latitude values.

[0052] The latitude plate 100 is provided with a first bayonet 130, which extends from a side close to the low latitude geographic latitude scale 110. Figure 1 This embodiment further includes a latitude support plate 600, which has second snap-in openings on one side near both ends. Specifically, the latitude support plate 600 has strip-shaped grooves 610 near both ends. The latitude support plate 600 is folded in half along its centerline, so that the strip-shaped grooves 610 at both ends of the latitude support plate 600 form second snap-in openings on one side of the latitude support plate 600. The second snap-in openings at both ends of the latitude support plate 600 correspond one-to-one with the first snap-in openings 130 on the two latitude plates 100, respectively, and thus the two latitude plates 100 can be fixed and positioned by the latitude support plate 600.

[0053] Reference Figure 1 、 Figure 4 、 Figure 5 and Figure 6 The dial plate 200 is formed by folding the front face 210 and the back face 220 of the dial plate in half. The sides of the front face 210 and the back face 220 of the dial plate away from the folding line are both provided with a concave arc edge 230. The front face 210 of the dial plate is provided with a geographic longitude scale 240 along the arc edge. The dial plate 200 is fixed to one side of the two latitude plates 100, and the concave arc edge 230 of the dial plate 200 faces obliquely upward.

[0054] Reference Figure 2 and Figure 7The sundial plate 300 is clamped between the front face 210 and the back face 220 of the dial face fixing plate 200. The sundial plate 300 is concentric with the center of the concave arc edge 230. A style 310 is provided in the center of the sundial plate 300 and passes through both sides. Time scales 320 are provided on the front and back of the sundial plate 300. The front of the sundial plate 300 is also provided with a geographic longitude alignment line 330, a date scale 340, and a true mean time difference value diagram 350 corresponding to the date scale 340. The geographic longitude alignment line 330 is aligned with the geographic longitude of the observation site corresponding to the geographic longitude scale 240.

[0055] In order to position the sundial plate 300 for installation, this embodiment further includes a positioning lining 500, which is sandwiched between the front face 210 and the back face 220 of the dial-face fixing plate 200. One side of the positioning lining 500 is provided with a positioning arc edge 510 that matches the arc edge of the sundial plate 300. In this way, when the sundial plate 300 is inserted between the front face 210 and the back face 220 of the dial-face fixing plate 200, it can be positioned by the positioning lining 500, which helps to improve the installation accuracy of the sundial plate 300.

[0056] Preferably, a first snap-fitting protrusion 120 is provided on one side of the latitude plate 100, and first snap-fitting grooves 250 are provided on both ends of the dial face fixing plate front 210, the dial face fixing plate back 220 and the positioning lining 500. The first snap-fitting grooves 250 on the dial face fixing plate front 210, the dial face fixing plate back 220 and the positioning lining 500 are aligned and overlapped respectively, and each first snap-fitting protrusion 120 is respectively snapped into a corresponding and overlapping first snap-fitting groove 250 on the dial face fixing plate front 210, the dial face fixing plate back 220 and the positioning lining 500. In this way, after the first snap-fitting protrusion 120 is snapped into the first snap-fitting groove 250, it can be fixed to the dial face fixing plate front 210, the dial face fixing plate back 220 and the positioning lining 500 at the same time, which not only facilitates assembly, but also enables the positioning lining 500 to be positioned and installed, thereby ensuring the installation accuracy of the sundial plate 300.

[0057] The gnomon 310 can be made of a disposable toothpick for easy material collection. To ensure that the gnomon 310 is vertically fixed to the center of the dial face, the gnomon 310 passes through the center of the sundial plate 300. The gnomon 310 is provided with a front fixing plate 311 positioned on the front of the sundial plate 300 and a rear fixing plate 312 positioned on the back of the sundial plate 300.

[0058] Reference Figure 1 and Figure 8 One end of the time difference quick-checking ruler 400 is provided with a first positioning hole 410 that can be positioned on the sundial 310, and the time difference quick-checking ruler 400 is provided with a time difference scale 420 extending from the first positioning hole 410 to the distal end.

[0059] When using the sundial, the sundial plate 300 can be rotated to align the geographic longitude alignment line 330 on the sundial plate 300 with the geographic longitude of the observation location corresponding to the geographic longitude scale 240 on the dial plate fixing plate 200. This allows the sundial plate 300 to be corrected according to the geographic longitude of the observation location to achieve the purpose of correcting the longitude time difference. At the same time, the time difference speed checker 400 can also be used to quickly check the time difference value on the sundial plate 300. The method for checking is: the first positioning hole 410 on the time difference speed checker 400 is positioned on the gnomon 310, and then the time difference speed checker 400 is rotated so that the time difference speed checker 400 is aligned with the observation date corresponding to the date scale 340. The reading at the intersection of the time difference speed checker 400 and the true time difference value graph 350 is read to obtain the time difference value.

[0060] For example: Figure 9 As shown, if the observation date is July 10, the positioning hole on the time difference speed checker 400 is positioned on the sundial 310, and the time difference speed checker 400 is rotated so that the pointer is aligned with the date July 10. The intersection of the true time difference value graph 350 on the dial and the time difference speed checker 400 is observed, and the time difference value is found to be between 5.6 and 5.8.

[0061] The sundial time can be directly read from the time scale 320 indicated by the shadow of the style 310 on the sundial plate 300, and then the Beijing time = sundial time + time difference can be calculated.

[0062] Therefore, the present application can be widely applicable in different locations, is convenient for measuring time differences, and is convenient for quickly converting sundial time into Beijing time.

[0063] like Figure 2 、 Figure 10 、 Figure 11 and Figure 12 As shown, this embodiment further includes a solar term scale 700 and two solar term scale support plates 730 .

[0064] The solar term scale 700 includes a solar term scale positioning plate 710 and a solar term scale plate 720. The solar term scale positioning plate 710 and the solar term scale plate 720 form a vertical L-shaped structure. A second positioning hole 711 capable of being positioned on the sundial 310 is provided at one end of the solar term scale positioning plate 710 away from the solar term scale plate 720, and a solar term scale 721 is provided on the side of the solar term scale plate 720 close to the solar term scale positioning plate 710.

[0065] The solar term scale support plate 730 has two vertical sides, and second clamping protrusions 731 are provided on the two vertical sides of the solar term scale support plate 730. Second clamping grooves 732 are provided on both sides of the solar term scale positioning plate 710 and the solar term scale scale plate 720. The second clamping protrusions 731 on both sides of each solar term scale support plate 730 correspond one-to-one to the second clamping grooves 732 on the solar term scale positioning plate 710 and the solar term scale plate 720.

[0066] How to use the solar term scale 700: Figure 2 Remove the solar scale main board and solar scale support plate 730, first fold the solar scale main board along the dotted line into a right angle, and then snap the second snap-in protrusions 731 on both sides of the solar scale support plate 730 into the second snap-in grooves 732 on the solar scale positioning plate 710 and the solar scale scale plate 720 (as shown in the figure). Figure 10 When measuring the solar terms, position the second positioning hole 711 on the solar term scale positioning plate 710 on the gnomon 310, confirm that the distance between the gnomon tip and the solar term scale positioning plate 710 is equal to 30 mm, rotate the solar term scale 700 to the position indicated by the shadow of the gnomon 310, and the shadow of the gnomon 310 on the solar term scale 700 indicates the solar term interval of the day, as shown below. Figure 12 As shown, the shadow of the tip of the sundial 310 falls on the Qingming and Bailu lines. If the day is in the first half of the year, the day is near the "Qingming" solar term. If the day is in the second half of the year, the day is near the "Bailu" solar term.

[0067] The embodiment of the present invention further provides a method for manufacturing an equatorial sundial, comprising the following steps:

[0068] Step S10: remove two rectangular sector-shaped latitude plates 100 marked with geographic latitude scales 110 from the printed cardboard, and cut the latitude plates 100 according to the geographic latitude of the observation site. The values ​​of the geographic latitude scales 110 cut from the latitude plates 100 are the geographic latitude of the observation site.

[0069] Step S20: Remove the dial plate front 210, dial plate back 220, and positioning lining 500 of the dial plate 200 from the printed cardboard. Fold the dial plate front 210 and dial plate back 220 in half along the dotted line in the middle. Install the positioning lining 500 between the folded dial plate front 210 and dial plate back 220.

[0070] Step S30, assembling the two cut latitude plates 100 on the back sides of both ends of the dial fixed plate 200 respectively;

[0071] Step S40, removing the sundial plate 300 printed with the front and back patterns from the printed cardboard, and folding the front and back of the sundial plate 300 in half;

[0072] Step S50, passing the style 310 through the center of the sundial plate 300, and inserting the front fixing plate 311 and the rear fixing plate 312 from both ends of the style 310 to fix them on both sides of the sundial plate 300;

[0073] In step S60, the sundial plate 300 is inserted between the front surface 210 and the back surface 220 of the dial face fixing plate, and the sundial plate 300 is rotated so that the geographic longitude alignment line 330 on the sundial plate 300 is aligned with the geographic longitude of the observation site corresponding to the geographic longitude scale 240.

[0074] The components required for the equatorial sundial are integrated on cardboard by die-stamping. All the components can be removed from the cardboard by simple cutting and then assembled according to the design. The sundial stylus 310 can be used as a toothpick. The sundial has a simple structure and can be assembled by the user himself, making it easy to manufacture.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. An equatorial sundial, characterized in that: include: Latitude plate, the latitude plate having two sides, the angle between the two sides = 90° - the geographical latitude of the observation site, and two latitude plates are provided on the left and right sides; A dial plate, the dial plate being formed by folding the front and back of the dial plate in half, the front and back of the dial plate both having concave arc edges on the sides away from the folding line, the front of the dial plate having geographic longitude scales along the arc edges, the dial plate being fixed to one side of the two latitude plates, with the concave arc edges of the dial plate facing obliquely upwards; A sundial plate, the sundial plate being clamped between the front and back surfaces of the dial face fixing plate, the sundial plate being concentric with the center of the concave arc edge, a style being provided at the center of the sundial plate and extending through both sides, the sundial plate being provided with time scales on both the front and back surfaces, the front surface of the sundial plate also being provided with a geographic longitude alignment line, a date scale, and a true mean time difference diagram corresponding to the date scale, the geographic longitude alignment line being aligned with the geographic longitude of the observation location corresponding to the geographic longitude scale; A time difference speed-checking ruler is provided with a first positioning hole at one end thereof which can be positioned on a sundial, and a time difference scale extending from the first positioning hole toward a distal end thereof.

2. The equatorial sundial according to claim 1, wherein: The latitude plate is made of a right-angled sector plate, on which geographic latitude scales are provided. The central angle of the latitude plate actually required to be used is cut according to the geographic latitude of the observation site.

3. The equatorial sundial according to claim 1, wherein: The sundial further comprises a positioning lining which is sandwiched between the front and back sides of the dial face fixing plate. One side of the positioning lining is provided with a positioning arc edge which matches the arc edge of the sundial disk.

4. The equatorial sundial according to claim 3, wherein: A first snap-fitting protrusion is provided on one side of the latitude plate, and first snap-fitting grooves are provided on the front face of the dial face fixing plate, the back face of the dial face fixing plate, and both ends of the positioning lining. The first snap-fitting grooves on the front face of the dial face fixing plate, the back face of the dial face fixing plate, and the positioning lining are aligned and overlapped, and each first snap-fitting protrusion is respectively snapped into a corresponding overlapping first snap-fitting groove on the front face of the dial face fixing plate, the back face of the dial face fixing plate, and the positioning lining.

5. The equatorial sundial according to claim 1, wherein: The latitude plate is provided with a first bayonet, and the first bayonet extends from a side close to the low-latitude geographic latitude scale; It also includes a latitude support plate, and a second bayonet is provided on one side of the latitude support plate close to both ends. The second bayonet at both ends of the latitude support plate respectively corresponds to the first bayonet on the two latitude plates and is engaged with each other.

6. The equatorial sundial according to claim 5, characterized in that: The latitude support plate is provided with strip grooves near both ends. The latitude support plate is folded along the center line so that the strip grooves at both ends of the latitude support plate form a second bayonet on one side of the latitude support plate.

7. The equatorial sundial according to claim 1, wherein: The gnomon passes through the center of the sundial disk. The gnomon is provided with a front fixing plate positioned on the front of the sundial disk and a rear fixing plate positioned on the back of the sundial disk.

8. The equatorial sundial according to claim 1, wherein: It also includes a solar term scale, which includes a solar term scale positioning plate and a solar term scale scale plate. The solar term scale positioning plate and the solar term scale scale plate form a vertical L-shaped structure. The solar term scale positioning plate is provided with a second positioning hole capable of being positioned on the sundial at one end away from the solar term scale plate. The solar term scale plate is provided with a solar term scale on a side close to the solar term scale positioning plate.

9. The equatorial sundial according to claim 8, characterized in that: The solar term scale also includes two solar term scale support plates, each of which has two vertical side edges. Second clamping protrusions are provided on both vertical side edges of the solar term scale support plates. Second clamping grooves are provided on both sides of the solar term scale positioning plate and the solar term scale scale plate. The second clamping protrusions on both sides of each solar term scale support plate correspond one-to-one to the second clamping grooves on the solar term scale positioning plate and the solar term scale plate.

10. A method for manufacturing an equatorial sundial according to any one of claims 1 to 9, characterized in that: The steps include: Step S10: remove two rectangular sector-shaped latitude plates marked with geographic latitude scales from the printed cardboard, and cut the latitude plates according to the geographic latitude of the observation site, so that the geographic latitude scale values ​​of the cut latitude plates are the geographic latitude of the observation site; Step S20: Remove the dial plate front, dial plate back, and positioning lining of the dial plate from the printed paperboard, fold the dial plate front and dial plate back along the middle dotted line, and install the positioning lining between the folded dial plate front and dial plate back. Step S30, assembling the two cut latitude plates on the back sides of both ends of the sundial fixed plate respectively; Step S40, removing the sundial plate printed with the front and back patterns from the printed cardboard, and folding the front and back of the sundial plate in half; Step S50, passing the gnomon through the center of the sundial plate, and inserting the front fixing plate and the rear fixing plate from both ends of the gnomon respectively to fix them on both sides of the sundial plate; Step S60: insert the sundial plate between the front and back surfaces of the dial face fixing plate, and rotate the sundial plate so that the geographic longitude alignment line on the sundial plate is aligned with the geographic longitude of the observation site corresponding to the geographic longitude scale.

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