Land area measuring device

Abstract

The invention relates to the technical field of land area measurement, in particular to a land area measuring device. Comprising a shell, the shell is rotationally connected with a rotating frame, the rotating frame is rotationally connected with a laser transmitter, the shell is fixedly connected with a lens, the shell is slidably connected with a switch, and a reset tension spring is fixedly connected between the switch and the shell; the limiting frame is rotationally connected into the shell; and the two extrusion blocks are symmetrically distributed and fixedly connected to the laser transmitter, the shell is slidably connected with a first trigger frame, and the shell is slidably connected with a second trigger frame. According to the invention, the extrusion block extrudes the first trigger frame, and when the shell topples, the fixation of the laser transmitter is triggered, and the laser transmitter is fixed in the shell, so that the probability that the laser transmitter shakes is reduced, and thus the probability that an internal optical lens is damaged due to the shaking of the laser transmitter is reduced, and the service life of the laser transmitter is prolonged. And the maintenance cost of the laser transmitter is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of land area measurement, and in particular to a land area measurement device. Background Art

[0002] A land area measuring device is a device that uses laser to measure the land area. The land area measuring device includes a total station. The total station uses the laser transmitter inside it to emit laser to each corner point of the selected land to measure the distance between each corner point, so as to calculate the area of ​​the selected land. However, the surface of the land is generally not flat. In order to prevent the laser emitted by the laser transmitter from being deflected, the laser transmitter is generally allowed to rotate inside the total station, and the laser transmitter is kept in a stable state at all times by its own weight.

[0003] During the measurement of land area, the uneven land surface will cause the total station to tilt. Once affected by the external environment (such as strong winds or accidental touch by people), the total station will fall over. At this time, the laser generator will be subjected to vibration shock and shake inside the total station. When the laser emitter shakes to the extreme rotation angle, the instantaneous resistance encountered by the laser emitter will suddenly increase, which can easily cause damage to the optical lens in the laser emitter, thereby increasing the maintenance cost of the laser emitter. Summary of the invention

[0004] In order to overcome the disadvantages pointed out in the above background, the present invention provides a land area measuring device.

[0005] The technical solution of the present invention is: a land area measuring device, comprising: A housing, wherein the housing is rotatably connected to a rotating frame, the rotating frame is rotatably connected to a laser emitter, a lens is fixedly connected to the housing, a switch is slidably connected to the housing, and a reset tension spring is fixedly connected between the switch and the housing; A limit frame, rotatably connected to the housing, the limit frame being provided with a limit assembly for fixing the laser emitter; The extrusion blocks include two symmetrically distributed ones, both of which are fixed to one side of the laser emitter close to the rotating frame. The shell is slidably connected to a first trigger frame, and the extrusion block is used to squeeze the first trigger frame. A first elastic member is fixed between the first trigger frame and the shell. The shell is slidably connected to a second trigger frame, and a second elastic member is fixed between the second trigger frame and the shell. The first trigger frame is used to squeeze the second trigger frame to move, and the movement of the second trigger frame is used to limit the switch.

[0006] Further explanation: The two extrusion blocks are respectively located on both sides of the rotating frame, and the projection of the extrusion block in the direction of the lens is T-shaped.

[0007] Further explanation: The limiting component includes: A sliding block, which is slidably connected to the switch. A rotating block is rotatably connected to the sliding block, and the rotating block is fixedly connected to the limiting frame. The limiting frame is provided with symmetrically distributed first limiting parts, and the limiting frame is provided with a second limiting part. The symmetrically distributed first limiting parts and the second limiting part are both used to limit the laser emitter.

[0008] Further explanation: It further includes: A limiting block, which is fixedly connected to the position of the limiting frame close to the lens, and the limiting block is used to limit and block the laser emitter.

[0009] Further explanation: It further includes: A button, which is slidably connected to the switch. A third elastic member is fixedly connected between the button and the switch, and the button is used to squeeze the second trigger frame so that the second trigger frame disengages from the switch.

[0010] Further explanation: It further includes: A limit pin, which is slidably connected to the housing. A fourth elastic member is fixedly connected between the limit pin and the housing, and the button is used to squeeze the limit pin so that the limit pin disengages from the switch, and the limit pin is used to limit the switch.

[0011] Further explanation: It further includes: A first airbag, which is fixedly connected inside the housing and is used to protect the laser emitter.

[0012] Further explanation: It further includes: Two second airbags, which are symmetrically distributed and are both fixedly connected to the housing. The second airbags are communicated with the first airbag through a conduit.

[0013] Further explanation: The switch is provided with two symmetrically distributed inclined surfaces for creating a gap between the switch and the housing.

[0014] Further explanation: It further includes: A shielding member, which is fixedly connected to the housing, and the side of the shielding member away from the housing is fixedly connected to the switch.

[0015] The beneficial effects produced by the above technical solutions are as follows: 1. In the present invention, the extrusion block extrudes the first trigger frame. When the housing is tilted, the fixation of the laser emitter is triggered, and the laser emitter is fixed inside the housing to reduce the probability of the laser emitter shaking, thereby reducing the probability of damage to the internal optical lens of the laser emitter due to shaking, and further reducing the maintenance cost of the laser emitter; 2. The laser emitter is fixed by the first limiting part, the second limiting part and the limiting block. During the process of measuring the land area, the laser emitter remains stationary relative to the housing by its own weight, keeping the laser emitter stable and improving the accuracy of the laser emitter in measuring the land area. During the transportation of the laser emitter, the laser emitter is fixed to reduce the probability of the laser emitter shaking; 3. The deformation of the second airbag buffers the housing to reduce the impact force when the housing is tilted, and makes the first airbag expand and wrap the laser emitter, increasing the stability of the laser emitter, thereby reducing the probability of damage to the housing and the laser emitter after they are tilted, and reducing the maintenance cost of the device; 4. The sliding connection part of the switch is blocked by the shielding part to reduce the probability of impurities getting stuck in the sliding connection part of the switch, so as to ensure that the switch can move to the extreme position, thereby ensuring that the limiting frame can be flipped to the extreme state, enabling the first limiting part, the second limiting part and the limiting block to all closely adhere to the laser emitter, reducing the probability of the laser emitter shaking, and improving the stability of the laser emitter during placement and transportation. Description of the Drawings

[0016] Figure 1 is a three-dimensional structural schematic diagram of the present invention; Figure 2 is a three-dimensional structural sectional view of the housing of the present invention; Figure 3 is a three-dimensional structural schematic diagram of the rotating frame of the present invention; Figure 4 is a three-dimensional structural schematic diagram of the laser emitter of the present invention; Figure 5 is a three-dimensional structural schematic diagram of the extrusion block of the present invention; Figure 6 is a three-dimensional structural schematic diagram of the sliding block of the present invention; Figure 7 is a three-dimensional structural schematic diagram of the limit pin of the present invention.

[0017] The markings in the figure are: 1 - outer shell, 2 - rotating frame, 3 - laser emitter, 4 - lens, 5 - switch, 6 - limiting frame, 7 - pressing block, 8 - first trigger frame, 9 - second trigger frame, 10 - sliding block, 11 - rotating block, 12 - first limiting part, 13 - second limiting part, 14 - limiting block, 15 - button, 16 - limiting pin, 17 - first airbag, 18 - second airbag, 19 - inclined surface part, 20 - shielding part. Detailed implementation mode

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation modes, but the protection scope and application scope of the present invention are not limited.

[0019] A land area measuring device, as Figures 1-7 shown, includes: an outer shell 1, an integrated circuit board not shown is provided inside the outer shell 1, a control terminal not shown is provided on the outer shell 1, the outer shell 1 is rotatably connected to a rotating frame 2, the rotating frame 2 is rotatably connected to a laser emitter 3, the laser emitter 3 is electrically connected to the control terminal, a lens 4 is fixedly connected to the outer shell 1, two switches 5 symmetrically distributed front and back are slidably connected to the outer shell 1, and a return tension spring is fixedly connected between the switch 5 and the outer shell 1; a limiting frame 6, rotatably connected inside the outer shell 1, the limiting frame 6 is provided with a limiting component for fixing the laser emitter 3. Taking Figure 1 the front view as the reference of the rotation direction, when the switch 5 moves to the left, the limiting frame 6 is rotated counterclockwise through the limiting component, and the limiting frame 6 fixes the laser emitter 3. When the switch 5 moves to the right, the limiting frame 6 is rotated clockwise through the limiting component, and the limiting frame 6 loses contact with the laser emitter 3; pressing blocks 7, having two symmetrically distributed left and right, are both fixedly connected to the upper side of the laser emitter 3, the left and right two pressing blocks 7 are respectively located on the left and right sides of the rotating frame 2, the projection of the pressing block 7 on the right side surface of the lens 4 is T-shaped, a first trigger frame 8 is slidably connected to the outer shell 1, the pressing block 7 is used to press the first trigger frame 8, and a first elastic member is fixedly connected between the first trigger frame 8 and the outer shell 1, wherein the first elastic member is a compression spring. Two second trigger frames 9 symmetrically distributed are slidably connected to the outer shell 1, a second elastic member is fixedly connected between the second trigger frame 9 and the outer shell 1, wherein the second elastic member is a tension spring. The first trigger frame 8 is provided with two first guiding inclined surfaces, the second trigger frame 9 is provided with a second guiding inclined surface. When the first trigger frame 8 moves upward, the first trigger frame 8 presses the second guiding inclined surface of the adjacent second trigger frame 9 through its first guiding inclined surface, so that the second trigger frame 9 moves horizontally. A third guiding inclined surface is provided on the left part of the second trigger frame 9, and the movement of the second trigger frame 9 is used to limit the adjacent switch 5 to limit the switch 5 from sliding to the left.

[0020] As Figures 3-6As shown in the figure, the limiting component includes: sliding blocks 10, with two symmetrically distributed front and back, respectively slidingly connected to adjacent switches 5. The sliding block 10 is rotatably connected to a rotating block 11, and the rotating block 11 is fixedly connected to the limiting frame 6. By setting two switches 5, the rotation of the limiting frame 6 is made more stable. The limiting frame 6 is provided with first limiting parts 12 symmetrically distributed front and back, and the limiting frame 6 is provided with second limiting parts 13. The first limiting parts 12 and the second limiting parts 13 are respectively located on the left and right sides of the laser emitter 3. The first limiting parts 12 and the second limiting parts 13 symmetrically distributed front and back are both used to limit the laser emitter 3. After the limiting frame 6 rotates to contact the laser emitter 3, the second limiting part 13 blocks the laser emitter 3. The second limiting part 13 is used to limit the counterclockwise flipping of the rotating frame 2 and the laser emitter 3 (the rotation angle is based on Figure 1 the front view). The first limiting parts 12 symmetrically distributed front and back are used to block the laser emitter 3 from flipping in the front and back directions.

[0021] As Figures 3-5 shown, it also includes: a limiting block 14, fixedly connected to the limiting frame 6 near the lens 4. The limiting block 14 is used to limit and block the laser emitter 3. After the laser emitter 3 stops being used, the limiting block 14 blocks the laser emitter 3 to reduce the influence of external sunlight direct irradiation on the optical lens in the laser emitter 3.

[0022] As Figure 4 shown in Figure 7 it also includes: a button 15, slidingly connected to the switch 5. A third elastic member is fixedly connected between the button 15 and the switch 5. The third elastic member is a compression spring. The button 15 is used to squeeze the second trigger frame 9 so that the second trigger frame 9 disengages from the switch 5, and then the switch 5 can move to the left.

[0023] As Figure 6 shown in Figure 7 it also includes: a limit pin 16, slidingly connected to the housing 1. A fourth elastic member is fixedly connected between the limit pin 16 and the housing 1. The fourth elastic member is a tension spring. The elastic coefficient of the return tension spring of the switch 5 is greater than that of the fourth elastic member. The button 15 is used to squeeze the limit pin 16 so that the limit pin 16 disengages from the switch 5. When the left side of the switch 5 is in contact with the housing 1, the limit pin 16 is inserted into the switch 5, and the limit pin 16 limits the switch 5.

[0024] Initially, when the laser emitter 3 is not in use, the switch 5 is in the left extreme state, the return tension spring of the switch 5 is in the un-stretched state, the left part of the limiting frame 6 flips down to the extreme state, the two first limiting parts 12, the second limiting parts 13 and the limiting block 14 jointly fix the laser emitter 3, and the second elastic member of the second trigger frame 9 is initially in the state of being compressed for energy storage.

[0025] The specific working principle is as follows: When the operator needs to use this device to measure the land area, select each corner point of the land area to be measured, then install the outer shell 1 on the bracket and place it at the designated position. The operator presses the button 15, the third elastic member of the button 15 is compressed, the button 15 squeezes the limit pin 16, and the fourth elastic member of the limit pin 16 is stretched. The limit pin 16 disengages from the limit of the switch 5. The operator slides the switch 5 to the right, and the return spring of the switch 5 is stretched. The switch 5 drives the slider 10 to move horizontally, so that the upper part of the rotating block 11 moves to the right. The rotating block 11 drives the limit frame 6 to rotate (at this time, the slider 10 moves vertically along the switch 5, and the rotating block 11 rotates relative to the slider 10), so that the left part of the limit frame 6 flips upward, and the two first limit parts 12, the second limit part 13 and the limit block 14 no longer fix the laser emitter 3. After the switch 5 slides to the right (after the switch 5 loses contact with the limit pin 16, the fourth elastic member of the limit pin 16 rebounds and resets. After the switch 5 moves to the right and fits with the outer shell 1, the operator releases the button 15, the third elastic member of the button 15 rebounds and drives it to reset, and the second elastic member of the second trigger frame 9 pops out. The second trigger frame 9 is inserted into the switch 5 and limits the switch 5), the control terminal turns on the laser emitter 3, and the laser emitter 3 emits laser to each corner point in turn to measure the distance between each corner point of the selected land, so as to calculate the area of the selected land through the control terminal.

[0026] If the ground is uneven, resulting in the outer shell 1 tilting in the left-right direction, the rotating frame 2 rotates relative to the outer shell 1 under the influence of its own weight and the weight of the laser emitter 3, so that the rotating frame 2 and the laser emitter 3 maintain a stable state. If the ground is uneven, resulting in the outer shell 1 tilting in the front-back direction, the laser emitter 3 maintains a stable state relative to the ground under the influence of its own gravity, and the laser emitter 3 rotates relative to the rotating frame 2 to make the rotating frame 2 and the laser emitter 3 maintain a stable state relative to the ground, improving the stability of the laser emitted by the laser emitter 3, thereby ensuring the accuracy of the land area measurement.

[0027] After the measurement of some corner points of the selected land is completed, the operator presses the button 15, the third elastic member of the button 15 is compressed, the button 15 squeezes the second trigger frame 9 to move, the second elastic member of the second trigger frame 9 is stretched, so that the second trigger frame 9 is separated from the switch 5, and then the operator pushes the switch 5 to the left to reset the switch 5 to the left, the reset spring of the switch 5 is no longer stretched and stored, the switch 5 drives the upper part of the rotating block 11 to move to the left through the sliding block 10, the sliding block 10 slides downward on the switch 5, and the rotating block 11 moves relative to the switch 5. When the sliding block 10 rotates counterclockwise, the rotating block 11 drives the limit frame 6 to rotate, so that the left part of the limit frame 6 flips downward. When the switch 5 moves to contact the limit pin 16, the limit pin 16 is pressed and moved, and the fourth elastic member of the limit pin 16 is stretched. When the switch 5 moves to the left to the extreme position, the button 15 moves to press the limit pin 16. The operator releases the button 15, and the third elastic member of the button 15 rebounds and resets, so that the button 15 no longer presses the limit pin 16. The limit pin 16 is inserted into the switch 5 to limit the switch 5.

[0028] When the switch 5 moves to the left to the extreme position, the left part of the limit frame 6 flips downward to the extreme state, and the limit frame 6 drives the two first limit parts 12, the second limit part 13 and the limit block 14 to rotate. The two first limit parts 12 move to the front and rear sides of the clamped laser emitter 3, the limit block 14 moves to block the left side of the laser emitter 3, and the second limit part 13 moves to support the right side of the laser emitter 3. By restricting the laser emitter 3, the laser emitter 3 is prevented from shaking when not in use. At this time, the operator transports the device, changes the position of the device, and measures the remaining corner points of the selected land.

[0029] After the operator transports the device to a new location, the operator repeats the above steps to unlock the switch 5 and slides the switch 5 to the right. The switch 5 drives the rotating block 11 to move through the sliding block 10, and the rotating block 11 drives the limit frame 6 to rotate. The limit frame 6 drives the two first limit parts 12, the second limit part 13 and the limit block 14 to reset, and the rotating frame 2 and the laser emitter 3 can rotate relative to the housing 1 again.

[0030] Repeat the above steps and continuously measure the land area so that the laser emitter 3 can remain stable relative to the ground by relying on its own weight during use. During the transportation of the laser emitter 3, the laser emitter 3 is fixed to reduce the probability of shaking of the laser emitter 3.

[0031] In the process of using the device to measure the land area, if the housing 1 is placed unstably and disturbed by the external environment, resulting in the housing 1 toppling over, the housing 1 and the laser emitter 3 rotate relative to each other, and the housing 1 drives the first trigger frame 8 to rotate, so that one of the extrusion blocks 7 squeezes the first trigger frame 8 to move, and the first trigger frame 8 moves upward under pressure, and the first elastic member of the first trigger frame 8 is compressed, and the first trigger frame 8 moves upward and squeezes the second trigger frame 9 through the first guide slope, so that the second trigger frame 9 moves to a position away from the switch 5, and the second trigger frame 9 loses the limit on the switch 5, and the reset tension spring of the switch 5 is no longer After being stretched, the reset tension spring of the switch 5 rebounds to make the switch 5 move to the left, and the switch 5 drives the rotating block 11 to move to the left through the sliding block 10, and the rotating block 11 drives the limit frame 6 to rotate, and the limit frame 6 drives the two first limit parts 12, the second limit part 13 and the limit block 14 to rotate, and the two first limit parts 12, the second limit part 13 and the limit block 14 are rotated to fix the laser emitter 3, and the laser emitter 3 is fixed in the housing 1 to reduce the probability of shaking of the laser emitter 3, thereby reducing the probability of damage to the internal optical lens of the laser emitter 3 due to shaking, thereby reducing the maintenance cost of the laser emitter 3.

[0032] When the housing 1 falls over, the operator picks up the device, and then repeats the above steps to slide the switch 5 to the right, so that the limit frame 6 loses the fixation of the laser transmitter 3 again, and continues to use the device to measure the land area.

[0033] After using the device, the operator repeats the above steps to fix the laser emitter 3 with the limit frame 6, and then turns off the laser emitter 3 through the control terminal, and finally removes the shell 1 from the bracket and collects the shell 1.

[0034] like Figure 2 As shown, it also includes: a first airbag 17, which is fixed in the housing 1. When the laser emitter 3 rotates to an extreme state, the first airbag 17 cushions the laser emitter 3 through its own deformation. The first airbag 17 is used to protect the laser emitter 3.

[0035] like Figure 1 and Figure 2 As shown, it also includes: a second airbag 18, with two symmetrically distributed front and back, both fixed to the shell 1, the second airbag 18 is connected to the first airbag 17 through a catheter, the first airbag 17 and the second airbag 18 are both made of elastic material, and the left and right sides of the second airbag 18 respectively wrap the left and right sides of the shell 1.

[0036] The specific working principle is as follows: When the device topples over, taking the example of the housing 1 toppling forward, the second airbag 18 on the front side first comes into contact with the ground. The second airbag 18 on the front side is deformed under pressure, and the gas inside the second airbag 18 on the front side is squeezed into the first airbag 17. The second airbag 18 protects the housing 1 and buffers the housing 1 through the deformation of the second airbag 18 to reduce the impact force when the housing 1 topples over. Moreover, the first airbag 17 expands and wraps the laser emitter 3 to increase the stability of the laser emitter 3, thereby reducing the probability of damage to the housing 1 and the laser emitter 3 after they topple over, and reducing the maintenance cost of the device.

[0037] When the housing 1 stops toppling, both the first airbag 17 and the second airbag 18 rebound and reset, enabling the gas inside the first airbag 17 and the second airbag 18 to flow back to their original positions.

[0038] As Figure 6 shown in Figure 7 the figure, the switch 5 is provided with two inclined faces 19 that are symmetrically distributed left and right, which are used to create a gap between the switch 5 and the housing 1. Once impurities get stuck in the corner between the left rear edge of the switch 5 and the housing 1, it will cause the left side of the switch 5 to be unable to move to fit the housing 1, which will result in the failure of the limit frame 6 and its components to fix the laser emitter 3. When impurities (such as dust particles) get stuck between the switch 5 and the housing 1, the impurities are stored through the gap between the switch 5 and the housing 1, reducing the probability that the left side of the switch 5 cannot fit the housing 1.

[0039] As Figure 1 shown in Figure 7 the figure, it further includes: a shielding member 20, fixedly connected to the housing 1, and the right side of the shielding member 20 is fixedly connected to the switch 5, which is used to shield the left side of the switch 5, reducing the probability of impurities getting stuck on the left side of the switch 5, ensuring that the switch 5 can move left to the extreme position, so that the left part of the limit frame 6 can be flipped down to the extreme state, enabling both the two first limit parts 12, the second limit part 13, and the limit block 14 to tightly adhere to the laser emitter 3, reducing the probability of the laser emitter 3 shaking, and improving the stability of the laser emitter 3 during placement and transportation.

[0040] The above embodiments are only used to illustrate the technical concept and features of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A land area measuring device, characterized in that: Included are: A housing (1), the housing (1) being rotatably connected to a rotating frame (2), the rotating frame (2) being rotatably connected to a laser emitter (3), the housing (1) being fixedly connected to a lens (4), the housing (1) being slidably connected to a switch (5), a reset tension spring being fixedly connected between the switch (5) and the housing (1); A limit frame (6) rotatably connected to the housing (1), the limit frame (6) being provided with a limit assembly for fixing the laser emitter (3); The extrusion blocks (7) have two symmetrically distributed ones, both of which are fixedly connected to a side of the laser emitter (3) close to the rotating frame (2); the housing (1) is slidably connected to a first trigger frame (8); the extrusion block (7) is used to squeeze the first trigger frame (8); a first elastic member is fixedly connected between the first trigger frame (8) and the housing (1); the housing (1) is slidably connected to a second trigger frame (9); a second elastic member is fixedly connected between the second trigger frame (9) and the housing (1); the first trigger frame (8) is used to squeeze the second trigger frame (9) to move; the movement of the second trigger frame (9) is used to limit the switch (5).

2. A land area measuring device according to claim 1, characterized in that: The two extrusion blocks (7) are respectively located on two sides of the rotating frame (2); the projection of the extrusion blocks (7) in the direction of the lens (4) is T-shaped.

3. A land area measuring device according to claim 1, characterized in that: The limit assembly includes: A sliding block (10) is slidably connected to the switch (5); the sliding block (10) is rotatably connected to a rotating block (11); the rotating block (11) is fixedly connected to the limiting frame (6); the limiting frame (6) is provided with symmetrically distributed first limiting portions (12); the limiting frame (6) is provided with a second limiting portion (13); the symmetrically distributed first limiting portions (12) and the second limiting portions (13) are both used to limit the laser emitter (3).

4. A land area measuring device according to claim 3, characterized in that: Also included are: A limit block (14) is fixedly connected to a position of the limit frame (6) close to the lens (4), and the limit block (14) is used to limit and shield the laser emitter (3).

5. A land area measuring device according to claim 3, characterized in that: Also included are: A button (15) is slidably connected to the switch (5), a third elastic member is fixedly connected between the button (15) and the switch (5), and the button (15) is used to press the second trigger frame (9) so that the second trigger frame (9) is separated from the switch (5).

6. A land area measuring device according to claim 5, characterized in that: Also included are: A limit pin (16) is slidably connected to the housing (1), a fourth elastic member is fixedly connected between the limit pin (16) and the housing (1), the button (15) is used to press the limit pin (16) so that the limit pin (16) is separated from the switch (5), and the limit pin (16) is used to limit the switch (5).

7. A land area measuring device according to claim 6, characterized in that: Also included are: A first airbag (17) is fixedly connected to the housing (1) and is used to protect the laser emitter (3).

8. A land area measuring device according to claim 7, characterized in that: Also included are: The second airbags (18) have two symmetrically distributed airbags, both of which are fixed to the housing (1); the second airbags (18) are connected to the first airbag (17) via a conduit.

9. A land area measuring device according to claim 8, characterized in that: The switch (5) is provided with two symmetrically distributed inclined portions (19) for providing a gap between the switch (5) and the housing (1).

10. A land area measuring device according to claim 9, characterized in that: Also included are: The shielding member (20) is fixedly connected to the housing (1), and a side of the shielding member (20) away from the housing (1) is fixedly connected to the switch (5).

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