Pitch adjusting mechanism suitable for liquid fertilizer spraying device

Abstract

The utility model relates to a pitching adjusting mechanism suitable for a liquid fertilizer spraying device, which is arranged on the liquid fertilizer spraying device, the liquid fertilizer spraying device comprises a pitching adjusting pipe section, the pitching adjusting pipe section comprises a left push rod supporting pipe and a right push rod supporting pipe, and a spray head is arranged at the front end of the liquid fertilizer spraying device. The pitching adjusting mechanism comprises a corrugated pipe, and the left push rod supporting pipe and the right push rod supporting pipe are in butt joint through the corrugated pipe. An upper push rod is arranged above the corrugated pipe, the upper push rod is a telescopic rod and can extend forwards or retract backwards, the upper push rod is provided with a stepping motor, and when an output shaft of the stepping motor moves forwards, the upper push rod extends forwards to enable the spray head to bend downwards forwards, so that the organic liquid fertilizer is sprayed outwards at the depression angle; and when the output shaft of the stepping motor moves backwards, the upper push rod shrinks backwards, so that the spray head tilts backwards, and the organic liquid fertilizer is sprayed outwards at an elevation angle.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery parts, specifically to a pitch adjustment mechanism suitable for liquid fertilizer spraying devices. Background Technology

[0002] Traditional organic liquid fertilizer spraying devices have significant limitations in existing agricultural production. They lack an effective elevation angle adjustment mechanism, resulting in a fixed spraying angle that is difficult to adjust flexibly according to different operating scenarios and actual needs. Especially when facing complex terrain, a fixed spraying angle can easily lead to uneven coverage of the target area by the liquid fertilizer, affecting fertilization effectiveness. Furthermore, the inability to adjust the spraying distance also limits its applicability, making it difficult to achieve ideal spraying effects and efficiency in special terrains or for specific crops.

[0003] In summary, current liquid fertilizer spraying devices cannot adjust the elevation and depression angles of the nozzles, resulting in unsatisfactory spraying effects and efficiency. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a pitch adjustment mechanism suitable for liquid fertilizer spraying devices, which solves the problem that current liquid fertilizer spraying devices cannot adjust the pitch and angle of the nozzle, resulting in unsatisfactory spraying effects and efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model discloses a pitch adjustment mechanism suitable for a liquid fertilizer spraying device, which is installed on the liquid fertilizer spraying device. The liquid fertilizer spraying device includes a pitch adjustment pipe section, which includes a left push rod support pipe and a right push rod support pipe. A nozzle is provided at the front end of the liquid fertilizer spraying device.

[0007] The pitch adjustment mechanism is mounted on the pitch adjustment tube section and includes a corrugated pipe, and the left push rod support tube and the right push rod support tube are connected through the corrugated pipe;

[0008] An upper push rod is disposed above the bellows.

[0009] The upper push rod is a telescopic rod that can extend forward or retract backward. The upper push rod is equipped with a stepper motor. When the output shaft of the stepper motor moves forward, the upper push rod extends forward, causing the nozzle to tilt forward so as to spray the organic liquid fertilizer outward at a downward angle. When the output shaft of the stepper motor moves backward, the upper push rod retracts backward, causing the nozzle to tilt backward so as to spray the organic liquid fertilizer outward at an upward angle.

[0010] Furthermore, the right end of the left push rod support tube and the left end of the right push rod support tube are respectively connected to both ends of the bellows.

[0011] Furthermore, each end of the corrugated pipe is equipped with a clamp, the right end of the left push rod support tube is connected to the left end of the corrugated pipe through the clamp and is tightened and fixed with a clamp set screw; the left end of the right push rod support tube is connected to the right end of the corrugated pipe through the clamp and is tightened and fixed with a clamp set screw.

[0012] Furthermore, the right end of the left push rod support tube and the left end of the right push rod support tube are respectively provided with a left ear plate and a right ear plate, and the two ends of the upper push rod are respectively fixed to the left ear plate and the right ear plate.

[0013] Furthermore, the outer ends of the left ear plate and the right ear plate are respectively provided with ear holes, and the two ends of the upper push rod are respectively fixed to the ear holes of the left ear plate and the right ear plate by push rod fixing bolts.

[0014] Furthermore, the distance between the ear hole at the outer end of the left ear plate and the left push rod support tube is greater than the distance between the ear hole at the outer end of the right ear plate and the right push rod support tube.

[0015] Furthermore, a left-handed arm and a right-handed arm are respectively arranged on the left and right sides of the bellows;

[0016] Both the left and right rotating arms include a left link and a right link, and the left link and the right link are pivotally connected by a pivot.

[0017] Once the front end of the bellows bends relative to the rear end, the left and right links of the left and right rotating arms simultaneously bend toward the pivot, guarding the left and right sides of the bellows to prevent it from shifting to the left or right.

[0018] Furthermore, the right end of the left rod and the left end of the right rod are respectively provided with pivot holes. After the pivot holes of the left rod and the right rod are aligned, a bolt is inserted as a pivot, thereby realizing the pivot connection of the two rods.

[0019] Furthermore, both ends of the left rod are bent inward at 90 degrees to form bent plates, and the clamp at the end of the corrugated pipe is provided with a flange. The bent plates at both ends of the left rod and the flange of the clamp at the end of the corrugated pipe are respectively connected by a swivel set screw. Both ends of the right rod are bent inward at 90 degrees to form bent plates, and the clamp at the end of the corrugated pipe is provided with a flange. The bent plates at both ends of the right rod and the flange of the clamp at the end of the corrugated pipe are respectively connected by a swivel set screw.

[0020] Preferably, the range of bending of the front end of the bellows relative to the rear end is [-30°, 30°].

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] (I) This utility model discloses a pitch adjustment mechanism suitable for a liquid fertilizer spraying device. The liquid fertilizer spraying device includes a pitch adjustment pipe section, which comprises a left push rod support pipe and a right push rod support pipe. A nozzle is provided at the front end of the liquid fertilizer spraying device. The pitch adjustment mechanism is located on the pitch adjustment pipe section and includes a corrugated pipe. The left push rod support pipe and the right push rod support pipe are connected through the corrugated pipe. An upper push rod is positioned above the corrugated pipe. The upper push rod is a telescopic rod capable of extending forward or retracting backward. A stepper motor is mounted on the upper push rod. When the output shaft of the stepper motor moves forward, the upper push rod extends forward, causing the nozzle to tilt forward, thus spraying the organic liquid fertilizer outward at a downward angle. When the output shaft of the stepper motor moves backward, the upper push rod retracts backward, causing the nozzle to tilt backward, thus spraying the organic liquid fertilizer outward at an upward angle.

[0023] (II) This utility model discloses an elevation adjustment mechanism suitable for liquid fertilizer spraying devices. Operators can flexibly adjust the elevation or depression angle of the nozzle spraying liquid fertilizer according to the specific conditions of different working environments. Taking into full account the actual application needs, the stepper motor is controlled to precisely adjust the range of elevation angle (0-30°) or depression angle (-30°-0°) of the nozzle spraying liquid fertilizer, thereby adjusting the coverage of organic liquid fertilizer spraying, so that the liquid fertilizer is sprayed more accurately to the target area, greatly improving the spraying effect and efficiency.

[0024] (III) This utility model discloses an elevation adjustment mechanism suitable for liquid fertilizer spraying devices. Through careful design, it can precisely control the range of spray elevation or depression angles, allowing for flexible adjustment of the spray angle according to actual needs during tanker organic liquid fertilizer spraying operations, thereby significantly improving spraying effect and efficiency. The elevation adjustment mechanism disclosed in this utility model is widely applicable to various types of tanker organic liquid fertilizer spraying operations. Whether under different terrain conditions or for the fertilization needs of different crops, it demonstrates excellent performance, bringing great convenience and benefits to agricultural production. Attached Figure Description

[0025] Figure 1 This is a rear view of the rear end of the fertilizer tanker provided in Embodiment 1 of this utility model;

[0026] Figure 2 Is Figure 1 A schematic diagram showing the back of a fertilizer tanker truck after a liquid fertilizer spraying device has been installed.

[0027] Figure 3This is a front view of the liquid fertilizer spraying device provided in Embodiment 2 of this utility model;

[0028] Figure 4 yes Figure 3 Top view.

[0029] Figure 5 This is a top view of the pitch adjustment mechanism provided in Embodiment 3 of this utility model when it is in normal condition;

[0030] Figure 6 yes Figure 5 Front view;

[0031] Figure 7 yes Figure 5 The right view;

[0032] Figure 8 This is a front view of the pitch adjustment mechanism provided in Embodiment 3 of this utility model when it is in the downward tilt state;

[0033] Figure 9 yes Figure 8 The right view.

[0034] Explanation of reference numerals in the attached drawings: 100-fertilizer tanker truck, 101-fertilizer storage tank, 102-discharge pipe, 103-fertilizer injection interface, 104-injection switch valve, 105-left vent valve, 106-right vent valve;

[0035] 1-Fertilizer transport pipeline, 10-Fertilizer tanker docking interface, 11-Fertilizer tanker docking pipe section, 12-Bend section, 13-Pitch adjustment pipe section, 131-Left push rod support pipe, 1310-Left flange, 132-Right push rod support pipe, 1320-Right flange;

[0036] 2- Nozzle;

[0037] 3-Rotating mechanism;

[0038] 4-Pitch adjustment mechanism,

[0039] 40 - Corrugated pipe, 400 - Clamp, 401 - Clamp set screw;

[0040] 41-Upper push rod; 410-Stepper motor; 411-Left ear plate; 412-Right ear plate; 413-Push rod fixing bolt;

[0041] 42 - Left-handed rotating arm; 43 - Right-handed rotating arm;

[0042] 50 - Pivot, 51 - Left rod, 52 - Right rod, 53 - Bending plate, 530 - Rotary arm set screw. Detailed Implementation

[0043] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0044] It should be noted that in this invention, "front end" refers to the end pointing to the nozzle 2 or the end where the nozzle 2 is located in the fertilizer delivery pipeline 1, and "rear end" refers to the end pointing to the fertilizer tanker interface 10 or the end where the fertilizer tanker interface 10 is located in the fertilizer delivery pipeline 1. Similarly, "front" refers to the direction pointing to the nozzle 2, and "rear" refers to the direction pointing to the fertilizer tanker interface 10.

[0045] Example 1: A fertilizer tanker

[0046] Example 1 provides a fertilizer tanker truck, the structure of which will be described in detail below with reference to the accompanying drawings.

[0047] refer to Figure 1 and Figure 2 The fertilizer tanker truck 100 is a liquid fertilizer transport tanker truck, which is equipped with a fertilizer storage tank 101, which stores organic liquid fertilizer. A discharge pipe 102 is provided on the tank wall of the fertilizer storage tank 101. The inlet end of the discharge pipe 102 is connected to the discharge port of the fertilizer storage tank 101, and the outlet end of the discharge pipe 102 is located at the rear end of the fertilizer tanker truck 100.

[0048] The organic liquid fertilizer in the fertilizer storage tank 101 can be transported from the discharge port of the fertilizer storage tank 101 to the inlet of the discharge pipe 102, and then to the outlet of the discharge pipe 102.

[0049] In order to spray the organic liquid fertilizer in the fertilizer tanker 100, the discharge end of the discharge pipe 102 is provided with a fertilizer spraying interface 103 for connecting with the liquid fertilizer spraying device.

[0050] As is common knowledge in the field, in order to control the output of organic liquid fertilizer from the fertilizer injection interface 103, an injection switch valve 104 is provided on the pipeline where the fertilizer injection interface 103 is located.

[0051] To facilitate the emptying of the organic liquid fertilizer in the discharge pipe 102, the discharge end of the discharge pipe 102 also includes a left vent valve 105 and a right vent valve 106. The left vent valve 105 and the right vent valve 106 are located on the left and right sides of the lower part of the tail end of the fertilizer tanker 100, respectively. The fertilizer injection interface 103 is located at the upper part of the tail end of the fertilizer tanker 100. The fertilizer injection interface 103, the left vent valve 105 and the right vent valve 106 are respectively connected to the discharge end of the discharge pipe 102.

[0052] The connection relationship between the fertilizer injection interface 103, the left vent valve 105, and the right vent valve 106 at the tail end of the fertilizer tanker 100 and the discharge end of the discharge pipe 102 is as follows: Figure 2 As shown.

[0053] Specifically, the fertilizer storage tank 101 and its discharge pipe 102 of the fertilizer tanker truck 100 have good sealing and stability. The fertilizer tanker truck 100 is professionally designed to adapt to different road conditions and transportation distances, and can efficiently and safely transport organic liquid fertilizer to mountainous and hilly areas with complex terrain. During the transportation of organic liquid fertilizer, it ensures that the organic liquid fertilizer will not leak or deteriorate.

[0054] Example 2: A liquid fertilizer spraying device suitable for fertilizer tank trucks

[0055] Example 2 provides a liquid fertilizer spraying device suitable for fertilizer tankers, which is installed on the fertilizer tanker of Example 1. Its structure will be described in detail below with reference to the accompanying drawings.

[0056] refer to Figure 3 and Figure 4 The liquid fertilizer spraying device includes a fertilizer delivery pipe 1, a nozzle 2, a rotating mechanism 3, and a pitch adjustment mechanism 4.

[0057] The rear end of the fertilizer transport pipeline 1 serves as the input end, and the front end of the fertilizer transport pipeline 1 serves as the output end. The rear end of the fertilizer transport pipeline 1 is provided with a fertilizer tanker interface 10, and the front end is provided with a nozzle 2.

[0058] The fertilizer tanker docking interface 10 is used to connect with the fertilizer tanker 100 and receive the organic liquid fertilizer inside the fertilizer tanker 100, and the nozzle 2 is used to spray the organic liquid fertilizer in the fertilizer delivery pipeline 1 outward.

[0059] The fertilizer delivery pipeline 1 is equipped with a rotating mechanism 3, which enables the nozzle 2 to rotate relative to the rear end of the fertilizer delivery pipeline 1, thereby spraying organic liquid fertilizer outward in a rotating manner.

[0060] The fertilizer delivery pipeline 1 is also equipped with a pitch adjustment mechanism 4, which enables the nozzle 2 to tilt upward or downward, thereby spraying organic liquid fertilizer outward at an angle of elevation or depression.

[0061] As one specific implementation method, refer to Figure 3 The fertilizer transport pipeline 1 includes a fertilizer tanker docking section 11, a bend section 12, and an elevation adjustment section 13.

[0062] The fertilizer tanker truck connecting pipe section 11 is connected to the rear end of the bent pipe section 12 through the rotating mechanism 3. The front end of the bent pipe section 12 and the nozzle 2 are respectively connected to the two ends of the pitch adjustment pipe section 13, thereby forming a continuous fertilizer transport pipeline 1.

[0063] More specifically, the bottom and top surfaces of the rotating mechanism 3 are respectively provided with a fixed flange 31 and a rotating flange 32.

[0064] The rear end of the fertilizer tanker docking pipe section 11 is provided with a fertilizer tanker docking interface 10 for docking with the fertilizer tanker 100, and the front end is fixedly connected to the fixed flange 31 of the rotating mechanism 3.

[0065] The pitch adjustment pipe section 13 is provided with a left flange 1310 and a right flange 1320 at both ends, respectively.

[0066] The rear end of the bent pipe section 12 is fixed on the rotating flange 32 of the rotating mechanism 3, and the front end is connected to the left flange 1310 of the pitch adjustment pipe section 13 via a flange.

[0067] The nozzle 2 is equipped with a flange, and the flange of the nozzle 2 is connected to the right flange 1320 of the pitch adjustment pipe section 13 via a flange.

[0068] Specifically, the pitch adjustment mechanism 4 is mounted on the pitch adjustment pipe section 13.

[0069] Example 3: A pitch adjustment mechanism suitable for liquid fertilizer spraying devices

[0070] Example 3 provides a pitch adjustment mechanism suitable for a liquid fertilizer spraying device, which is installed on the pitch adjustment pipe section 13 of the liquid fertilizer spraying device in Example 2. Its structure will be described in detail below with reference to the accompanying drawings.

[0071] refer to Figures 5 to 7 The pitch adjustment mechanism 4 includes a bellows 40, and the pitch adjustment pipe section 13 includes a left push rod support pipe 131 and a right push rod support pipe 132, and the left push rod support pipe 131 and the right push rod support pipe 132 are connected through the bellows 40.

[0072] An upper push rod 41 is disposed above the bellows 40.

[0073] The upper push rod 41 is a telescopic rod that can extend forward or retract backward. The upper push rod 41 is equipped with a stepper motor 410. When the output axis of the stepper motor 410 moves forward, the upper push rod 41 extends forward, causing the nozzle 2 to tilt forward so as to spray the organic liquid fertilizer outward at a downward angle. When the output axis of the stepper motor 410 moves backward, the upper push rod 41 retracts backward, causing the nozzle 2 to tilt backward so as to spray the organic liquid fertilizer outward at an upward angle.

[0074] The left push rod support tube 131 and the right push rod support tube 132 are connected by a corrugated pipe 40 to form the pitch adjustment tube section 13.

[0075] As a specific embodiment for connecting the left push rod support tube 131 and the right push rod support tube 132 through the corrugated pipe 40, the right end of the left push rod support tube 131 and the left end of the right push rod support tube 132 are respectively connected to the two ends of the corrugated pipe 40.

[0076] More specifically, the two ends of the corrugated pipe 40 are respectively equipped with clamps 400.

[0077] The right end of the left push rod support tube 131 is connected to the left end of the corrugated pipe 40 by a clamp 400 and is tightened and fixed by a clamp set screw 401.

[0078] The left end of the right push rod support tube 132 is connected to the right end of the bellows 40 by a clamp 400 and is tightened and fixed by a clamp set screw 401.

[0079] To avoid interference between the upper push rod 41 and the bellows 40 during operation, a specific implementation method for setting the upper push rod 41 above the bellows 40 is as follows: the right end of the left push rod support tube 131 and the left end of the right push rod support tube 132 are respectively provided with a left ear plate 411 and a right ear plate 412, and the two ends of the upper push rod 41 are respectively fixed on the left ear plate 411 and the right ear plate 412.

[0080] More specifically, the outer ends of the left ear plate 411 and the right ear plate 412 are respectively provided with ear holes, and the two ends of the upper push rod 41 are respectively fixed to the ear holes of the left ear plate 411 and the right ear plate 412 by push rod fixing bolts 413.

[0081] In order to facilitate the bending of the front end of the bellows 40 relative to the rear end to produce an upward or downward tilt, preferably, the distance between the ear hole at the outer end of the left ear plate 411 and the left push rod support tube 131 is greater than the distance between the ear hole at the outer end of the right ear plate 412 and the right push rod support tube 132.

[0082] To improve the stability of the pitch adjustment mechanism 4 during the process of the upper push rod 41 causing the nozzle 2 to tilt down or up, a left-hand rotating arm 42 and a right-hand rotating arm 43 are respectively arranged on the left and right sides of the bellows 40.

[0083] The left rotating arm 42 and the right rotating arm 43 each include a left member 51 and a right member 52, and the left member 51 and the right member 52 are pivotally connected by a pivot 50.

[0084] Once the front end of the bellows 40 bends relative to the rear end, the left rod 51 and right rod 52 of the left rotating arm 42 and the right rotating arm 43 simultaneously bend toward the pivot 50, guarding the left and right sides of the bellows 40 to prevent the bellows 40 from shifting to the left or right.

[0085] As a specific implementation method for pivoting the left rod 51 and the right rod 52 via the pivot 50, the right end of the left rod 51 and the left end of the right rod 52 are respectively provided with pivot holes. After the pivot holes of the left rod 51 and the right rod 52 are aligned, a bolt is inserted as the pivot 50, thereby realizing the pivot connection of the two rods.

[0086] Furthermore, both ends of the left rod 51 are bent inward at 90 degrees to form bending plates 53. The clamp 400 at the end of the corrugated pipe 40 is provided with a flange. The bending plates 53 at both ends of the left rod 51 and the flange of the clamp 400 at the end of the corrugated pipe 40 are respectively connected by a swivel set screw 530.

[0087] Specifically, the bending plate 53 is provided with screw holes, and the flange of the clamp 400 at the end of the bellows 40 is provided with screw holes. When the screw holes of the bending plates 53 at both ends of the left rod 51 coincide with the screw holes of the flange of the clamp 400 at the end of the bellows 40, the rotating arm set screw 530 is inserted. Since screw connections are common knowledge in this technical field, they will not be described in detail here.

[0088] Similarly, both ends of the right rod 52 are bent inward at 90 degrees to form bending plates 53. The clamp 400 at the end of the corrugated pipe 40 is provided with a flange. The bending plates 53 at both ends of the right rod 52 and the flange of the clamp 400 at the end of the corrugated pipe 40 are respectively connected by a swivel set screw 530.

[0089] Preferably, the range of bending of the front end of the bellows 40 relative to the rear end is [-30°, 30°].

[0090] Specifically, when the front end of the bellows 40 effectively bends relative to its rear end within the range of 0 to 30°, the elevation angle of the nozzle 2 is changed; when the front end of the bellows 40 effectively bends relative to its rear end within the range of -30° to 0°, the depression angle of the nozzle 2 is changed. Figure 8 and Figure 9 As shown, this allows for adjustment of the coverage area of ​​the organic liquid fertilizer spray.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A pitch adjustment mechanism suitable for a liquid fertilizer spraying device, characterized in that, The liquid fertilizer spraying device is installed on the liquid fertilizer spraying device, which includes a pitch adjustment pipe section (13), the pitch adjustment pipe section (13) includes a left push rod support pipe (131) and a right push rod support pipe (132), and a nozzle (2) is provided at the front end of the liquid fertilizer spraying device. The pitch adjustment mechanism (4) is installed on the pitch adjustment tube section (13), including a bellows (40), and the left push rod support tube (131) and the right push rod support tube (132) are connected through the bellows (40); An upper push rod (41) is disposed above the bellows (40). The upper push rod (41) is a telescopic rod that can extend forward or retract backward. The upper push rod (41) is equipped with a stepper motor (410). When the output shaft of the stepper motor (410) moves forward, the upper push rod (41) extends forward, causing the nozzle (2) to tilt forward so as to spray the organic liquid fertilizer outward at a downward angle. When the output shaft of the stepper motor (410) moves backward, the upper push rod (41) retracts backward, causing the nozzle (2) to tilt backward so as to spray the organic liquid fertilizer outward at an upward angle.

2. The pitch adjustment mechanism according to claim 1, characterized in that, The right end of the left push rod support tube (131) and the left end of the right push rod support tube (132) are respectively connected to the two ends of the corrugated pipe (40).

3. The pitch adjustment mechanism according to claim 2, characterized in that, The two ends of the corrugated pipe (40) are respectively equipped with clamps (400). The right end of the left push rod support tube (131) is connected to the left end of the corrugated pipe (40) by a clamp (400) and is tightened and fixed by a clamp set screw (401); The left end of the right push rod support tube (132) is connected to the right end of the bellows (40) by a clamp (400) and is tightened and fixed by a clamp set screw (401).

4. The pitch adjustment mechanism according to claim 1, characterized in that, The right end of the left push rod support tube (131) and the left end of the right push rod support tube (132) are respectively provided with a left ear plate (411) and a right ear plate (412), and the two ends of the upper push rod (41) are respectively fixed on the left ear plate (411) and the right ear plate (412).

5. The pitch adjustment mechanism according to claim 4, characterized in that, The outer ends of the left ear plate (411) and the right ear plate (412) are respectively provided with ear holes, and the two ends of the upper push rod (41) are respectively fixed to the ear holes of the left ear plate (411) and the right ear plate (412) by push rod fixing bolts (413).

6. The pitch adjustment mechanism according to claim 5, characterized in that, The distance between the ear hole at the outer end of the left ear plate (411) and the left push rod support tube (131) is greater than the distance between the ear hole at the outer end of the right ear plate (412) and the right push rod support tube (132).

7. The pitch adjustment mechanism according to claim 1, characterized in that, The bellows (40) is provided with a left-handed arm (42) and a right-handed arm (43) on its left and right sides respectively. The left rotating arm (42) and the right rotating arm (43) each include a left member (51) and a right member (52), and the left member (51) and the right member (52) are pivotally connected by a pivot (50); Once the front end of the bellows (40) bends relative to the rear end, the left rod (51) and right rod (52) of the left rotating arm (42) and the right rotating arm (43) simultaneously bend toward the pivot (50) to guard the left and right sides of the bellows (40) to prevent the bellows (40) from shifting to the left or right.

8. The pitch adjustment mechanism according to claim 7, characterized in that, The right end of the left rod (51) and the left end of the right rod (52) are respectively provided with pivot holes. After the pivot hole of the left rod (51) and the pivot hole of the right rod (52) are overlapped, a bolt is inserted as a pivot (50), thereby realizing the pivot connection of the two rods.

9. The pitch adjustment mechanism according to claim 7, characterized in that, The two ends of the left rod (51) are bent inward at 90 degrees to form a bent plate (53). The clamp (400) at the end of the corrugated pipe (40) is provided with a flange. The bent plates (53) at both ends of the left rod (51) and the flange of the clamp (400) at the end of the corrugated pipe (40) are connected by a swivel set screw (530). The two ends of the right rod (52) are bent inward at 90 degrees to form a bent plate (53). The clamp (400) at the end of the corrugated pipe (40) is provided with a flange. The bent plates (53) at both ends of the right rod (52) and the flange of the clamp (400) at the end of the corrugated pipe (40) are respectively connected by a swivel set screw (530).

10. The pitch adjustment mechanism according to claim 7, characterized in that, The range of bending of the front end of the bellows (40) relative to the rear end is [-30º, 30º].

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