Telescopic mechanism, telescopic device and overhead working vehicle

Abstract

The application relates to the technical field of high-altitude machinery, and discloses a telescopic mechanism, a telescopic device and a high-altitude operation vehicle. The telescopic mechanism comprises a section arm, the section arm comprises a first section arm, a second section arm and a third section arm, and the first section arm, the second section arm and the third section arm are connected in a sleeving mode from outside to inside; a first two-stage oil cylinder is arranged in the section arm and comprises a first one-stage cylinder rod, a first two-stage cylinder rod and a first cylinder body, the first one-stage cylinder rod is connected with the first section arm, the first two-stage cylinder rod is connected with the second section arm, and the first cylinder body is connected with the third section arm; a first linkage assembly is used for driving the second section arm to move away from the first section arm through the movement away from each other between the third section arm and the second section arm. The telescopic device comprises the telescopic mechanism. The high-altitude operation vehicle comprises the telescopic device. The telescopic mechanism, the telescopic device and the high-altitude operation vehicle can improve the telescopic performance of the section arm and reduce the production cost.

Description

Technical Field

[0001] This invention belongs to the field of high-altitude machinery technology, specifically relating to a telescopic mechanism, telescopic device, and aerial work vehicle. Background Technology

[0002] As one of the core components for telescopic booms to achieve telescopic function, the telescopic mechanism generally achieves the telescopic extension and retraction of the boom sections through the cooperation of the telescopic cylinder C and the rope assembly P.

[0003] However, for a five-section telescopic boom, such as Figure 1 As shown, multiple rope assembly Ps are typically required inside, making the design quite complex. The increased load due to the increased number of boom sections places higher demands on the chains and pulleys in the rope assembly P, leading to higher production costs. Furthermore, since each boom section is driven by the same telescopic cylinder C, the load on the telescopic cylinder C is substantial, which not only negatively impacts the telescopic boom's extension and retraction performance but also poses certain safety hazards.

[0004] Even if multi-stage cylinders are used to reduce the number of rope assembly P, the fact that multi-stage cylinders can generally only extend and retract one stage at a time results in a large impact when each stage cylinder rod reaches its position, which is detrimental to the stability of the telescopic boom. Furthermore, multi-stage cylinders generally have greater thrust at lower stages, and the cylinders themselves are heavy and large in size, making it difficult to ensure the synchronization of extension and retraction among multiple cylinders when multiple multi-stage cylinders are used simultaneously. Summary of the Invention

[0005] The purpose of this invention is to provide a telescopic mechanism, telescopic device, and aerial work platform to improve the telescopic performance of the boom arm.

[0006] To achieve the above objectives, the present invention provides a telescopic mechanism, comprising:

[0007] The segmental arm includes a first segmental arm, a second segmental arm, and a third segmental arm nested sequentially from the outside in;

[0008] The first two-stage hydraulic cylinder includes a first-stage cylinder rod, a first-second-stage cylinder rod, and a first cylinder body. The first two-stage hydraulic cylinder is located inside the segment arm. The first-stage cylinder rod is connected to the first segment arm, the first-second-stage cylinder rod is connected to the second segment arm, and the first cylinder body is connected to the third segment arm.

[0009] The first linkage component is used to drive the second arm away from the first arm through the moving away motion between the third arm and the second arm.

[0010] In one alternative implementation, the first linkage component includes:

[0011] The first pulley is mounted on the left end of the second arm.

[0012] The first chain has one end connected to the right end of the first arm section, and after the first chain passes over the left end of the first pulley, the other end of the first chain is connected to the left end of the third arm section.

[0013] In one alternative implementation, the telescopic mechanism further includes a second linkage component, which includes:

[0014] The second pulley is mounted on the right end of the second section arm;

[0015] The second chain has one end connected to the right end of the first arm section, and after the second chain passes over the right end of the second pulley, the other end of the second chain is connected to the left end of the third arm section.

[0016] In one alternative implementation, the telescopic mechanism further includes:

[0017] The first distance sensor is used to obtain the relative distance between the first arm segment and the second arm segment.

[0018] In one alternative implementation, the first distance sensor is a pull-wire sensor, which is located at the left end of the first arm section, and the pull wire of the pull-wire sensor is connected to the left end of the second arm section.

[0019] A second aspect of the present invention provides a telescopic device, which includes the telescopic mechanism described above.

[0020] In one alternative implementation, the telescopic device further includes:

[0021] The fourth and fifth arm segments;

[0022] The second two-stage hydraulic cylinder includes a second-stage cylinder rod, a second-stage cylinder rod, and a second cylinder body. The second-stage cylinder rod is connected to the third arm section; the second-stage cylinder rod is connected to the fourth arm section; and the second cylinder body is connected to the fifth arm section.

[0023] The third linkage component is used to move the fourth arm away from the third arm by moving away from the fifth arm and the fourth arm through the moving motion between them.

[0024] In one alternative implementation, the third linkage component includes:

[0025] The third pulley is mounted on the left end of the fourth section arm;

[0026] The third chain has one end connected to the right end of the third arm section, and after the third chain passes over the left end of the third pulley, the other end of the third chain is connected to the left end of the fifth arm section.

[0027] In one alternative implementation, the telescopic device further includes a fourth linkage component, which includes:

[0028] The fourth pulley is mounted on the right end of the fourth section arm;

[0029] The fourth chain has one end connected to the right end of the third arm. After the fourth chain passes over the right end of the fourth pulley, the other end of the fourth chain is connected to the left end of the fifth arm.

[0030] In one alternative implementation, the telescopic device further includes:

[0031] The second distance sensor is used to obtain the relative distance between the fifth arm and the fourth arm.

[0032] In one alternative implementation, the second distance sensor is a pull-wire sensor, which is located at the left end of the third arm, and the pull wire of the pull-wire sensor is connected to the left end of the fourth arm.

[0033] In one alternative implementation, the telescopic device further includes:

[0034] The controller is configured as follows:

[0035] Based on the distance signals from the first and second distance sensors, the first and second stage hydraulic cylinders are controlled to extend the third and fifth arm sections proportionally from the second and fourth arm sections.

[0036] A third aspect of the present invention provides an aerial work platform vehicle, which includes the aforementioned telescopic device.

[0037] Through the above technical solution, a first two-stage hydraulic cylinder is introduced into the telescopic mechanism. The first-stage cylinder rod, the first-second-stage cylinder rod, and the first cylinder body are connected to the first, second, and third arm sections, respectively. The relative telescopic movement between the first-stage and first-second-stage cylinder rods realizes the relative telescopic movement between the first and second arm sections, and the relative telescopic movement between the second and third arm sections realizes the relative telescopic movement between the first-second-stage cylinder rod and the first cylinder body. Furthermore, a first linkage component is introduced, enabling the moving away movement between the third and second arm sections to move the second arm away from the first arm section, thereby reducing the load on the relative telescopic movement between the first-stage and first-second-stage cylinder rods. In addition, since the first-second-stage cylinder rods of the first two-stage hydraulic cylinder are larger and have a stronger load capacity than the first-stage cylinder rod, distributing the load from the first-stage cylinder rod to the first-second-stage cylinder rod allows for more effective utilization of the structural strength of the first two-stage hydraulic cylinder, thus reducing the overall size of the first two-stage hydraulic cylinder.

[0038] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. Those skilled in the art can obtain other drawings based on the structures shown in these drawings without any inventive effort. In the drawings:

[0040] Figure 1 This is a schematic diagram of the structure of a telescopic arm in the prior art;

[0041] Figure 2 This is a schematic diagram of the structure of a telescopic device according to a specific embodiment of the present invention.

[0042] Explanation of reference numerals in the attached figures

[0043] 10 First arm section 80 Fourth arm section

[0044] 20 Second arm 90 Fifth arm

[0045] 30 Third section arm 100 Second and second stage hydraulic cylinders

[0046] 40 First and second stage hydraulic cylinders 101 Second stage cylinder rod

[0047] 41 First-stage cylinder rod 102 Second-stage cylinder rod

[0048] 42 First and second stage cylinder rods 103 Second cylinder block

[0049] 43 First cylinder block 110 Third linkage assembly

[0050] 50 First linkage component 111 Third pulley

[0051] 51 First pulley 112 Third chain

[0052] 52 First chain 120 Fourth linkage component

[0053] 60 Second linkage component 121 Fourth pulley

[0054] 61 Second pulley 122 Fourth chain

[0055] 62 Second chain 130 Second distance sensor

[0056] 70 First distance sensor P rope assembly

[0057] C Telescopic cylinder Detailed Implementation

[0058] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0059] The telescopic mechanism, telescopic device, and aerial work platform according to the present invention are described below with reference to the accompanying drawings.

[0060] This invention discloses a novel telescopic mechanism, such as... Figure 2 As shown, the telescopic mechanism includes:

[0061] The segmental arm includes a first segmental arm 10, a second segmental arm 20, and a third segmental arm 30 nested sequentially from the outside in;

[0062] The first two-stage hydraulic cylinder 40 is located inside the segment arm and includes a first-stage cylinder rod 41, a first-stage cylinder rod 42, and a first cylinder body 43. The first-stage cylinder rod 41 is connected to the first segment arm 10, the first-stage cylinder rod 42 is connected to the second segment arm 20, and the first cylinder body 43 is connected to the third segment arm 30.

[0063] The first linkage component 50 is used to move the second arm 20 away from the first arm 10 by moving the third arm 30 away from the second arm 20 through a moving motion between the second arm 30 and the third arm 20.

[0064] Specifically, compared to the existing technology where a single-stage cylinder drives the relative movement of adjacent arm segments, and the rope assembly transmits this movement to other arm segments, this invention introduces a first two-stage cylinder 40. The first-stage cylinder rod 41, the first-stage cylinder rod 42, and the first cylinder body 43 of the first two-stage cylinder 40 are respectively connected to the first arm segment 10, the second arm segment 20, and the third arm segment 30. The relative movement between adjacent arm segments can be directly achieved by the first two-stage cylinder 40. Therefore, the load is more reasonable and the extension performance is better. In addition, this invention also introduces a first linkage assembly 50. The first linkage assembly 50 can drive the second arm segment 20 away from the first arm segment 10 through the moving away movement between the third arm segment 30 and the second arm segment 20. That is, the first-stage cylinder rod 42 can bear part of the load on the first-stage cylinder rod 41. Since the first-stage cylinder rod 42 of the first two-stage cylinder 40 is larger and has a stronger load capacity than the first-stage cylinder rod 41, this arrangement can more effectively utilize the structural strength of the first two-stage cylinder 40, thereby reducing the overall size of the first two-stage cylinder 40. As will be understood by those skilled in the art, the first linkage component 50 can take many forms, such as having corresponding gear and rack mechanisms on the first arm 10, the second arm 20, and the third arm 30, or a rope assembly including a fixed pulley and / or a movable pulley.

[0065] In this embodiment, such as Figure 2 As shown, the first linkage component 50 includes:

[0066] The first pulley 51 is mounted on the left end of the second arm 20.

[0067] First chain 52 ( Figure 2 (Only the portion of the first chain 52 between the first pulley 51 and the third arm 30 is shown in the image.) One end of the first chain 52 is connected to the right end of the first arm 10, and after the first chain 52 passes around the left end of the first pulley 51, the other end of the first chain 52 is connected to the left end of the third arm 30.

[0068] Specifically, when the first and second stage cylinder rod 42 extends from the first cylinder body 43, it can push the third arm 30 to extend from the second arm 20. At this time, the length of the first chain 52 between the first pulley 51 and the third arm 30 increases, and the length of the first chain 52 between the first pulley 51 and the first arm 10 decreases and pulls the second arm section. Thus, the first chain 52 can assist the second arm 20 to extend from the first arm 10, reducing the push-out load of the first stage cylinder rod 41.

[0069] In this embodiment, such as Figure 2 As shown, the telescopic mechanism also includes a second linkage component 60, which includes:

[0070] The second pulley 61 is mounted on the right end of the second arm 20.

[0071] Second chain 62 ( Figure 2 (Only the portion of the second chain 62 between the second pulley 61 and the first arm 10 is shown.) One end of the second chain 62 is connected to the right end of the first arm 10. After the second chain 62 passes over the right end of the second pulley 61, the other end of the second chain 62 is connected to the left end of the third arm 30.

[0072] Specifically, when the first and second stage cylinder rod 42 retracts, it can drive the third arm 30 to retract from the second arm 20. At this time, the length of the second chain 62 between the second pulley 61 and the third arm 30 is reduced, so the second chain 62 will push the second pulley 61 to the left, thereby driving the second arm 20 to retract into the first arm 10. This setting can reduce the retraction load of the first stage cylinder rod 41.

[0073] In this embodiment, such as Figure 2 As shown, the telescopic mechanism also includes:

[0074] The first distance sensor 70 is used to obtain the relative distance between the first arm 10 and the second arm 20.

[0075] Specifically, after obtaining the relative distance between the first arm 10 and the second arm 20, the relative positions of the first arm 10, the second arm 20 and the third arm 30 can be determined based on this relative distance.

[0076] In this embodiment, such as Figure 2 As shown, the first distance sensor 70 is a pull-wire sensor, which is located at the left end of the first arm 10, and the pull wire of the pull-wire sensor is connected to the left end of the second arm 20.

[0077] There are various distance sensors to choose from; pull-wire sensors are less expensive and easier to maintain and repair. See [link / reference] Figure 2 The left ends of the first arm 10 and the second arm 20 are connected by a pull wire, resulting in a compact overall design. The relative positions of the first arm 10, the second arm 20, and the third arm 30 can be determined based on the length of the pull wire.

[0078] The present invention also discloses a telescopic device, which includes the telescopic mechanism described above.

[0079] Clearly, this telescopic device possesses all the technical effects brought about by the aforementioned telescopic mechanism, so it will not be elaborated upon here.

[0080] In this embodiment, such as Figure 2 As shown, the telescopic device also includes:

[0081] The fourth arm is 80mm and the fifth arm is 90mm;

[0082] The second two-stage hydraulic cylinder 100 includes a second first-stage cylinder rod 101, a second second-stage cylinder rod 102, and a second cylinder body 103. The second first-stage cylinder rod 101 is connected to the third arm 30; the second second-stage cylinder rod 102 is connected to the fourth arm 80; and the second cylinder body 103 is connected to the fifth arm 90.

[0083] The third linkage component 110 is used to move the fourth arm 80 away from the third arm 30 by moving away from the fifth arm 90 and the fourth arm 80 through a moving motion.

[0084] Specifically, the third arm 30, fourth arm 80, and fifth arm 90 of the telescopic mechanism are sequentially connected from the outside to the inside. The second-stage cylinder rod 101, the second-stage cylinder rod 102, and the second cylinder body 103 are respectively connected to the third arm 30, the fourth arm 80, and the fifth arm 90. The relative movement between adjacent arms can be directly achieved by the second-stage hydraulic cylinder 100, thereby further improving the telescopicity between each arm and the load balance of each cylinder rod. Similarly, a third linkage component 110 is introduced into the telescopic device. The third linkage component 110 can drive the fourth arm 80 away from the third arm 30 through the moving away movement between the fourth arm 80 and the fifth arm 90, that is, the second-stage cylinder rod 102 can bear part of the load on the second-stage cylinder rod 101. Since the second-stage cylinder rod 102 of the second-stage hydraulic cylinder 100 is larger and has a stronger load capacity than the second-stage cylinder rod 101, this arrangement can more effectively utilize the structural strength of the second-stage hydraulic cylinder 100, thereby reducing the overall size of the second-stage hydraulic cylinder 100. As will be understood by those skilled in the art, the third linkage component 110 can take many forms, such as having corresponding gear and rack mechanisms on the third arm 30, the fourth arm 80, and the fifth arm 90, or a rope assembly including a fixed pulley and / or a movable pulley.

[0085] In this embodiment, such as Figure 2 As shown, the third linkage component 110 includes:

[0086] The third pulley 111 is mounted on the left end of the fourth section arm 80.

[0087] Third chain 112 ( Figure 2 (Only the portion of the third chain 112 between the third pulley 111 and the fifth arm 90 is shown.) One end of the third chain 112 is connected to the right end of the third arm 30, and after the third chain 112 passes over the left end of the third pulley 111, the other end of the third chain 112 is connected to the left end of the fifth arm 90.

[0088] Specifically, when the second-stage cylinder rod 102 extends from the second cylinder body 103, it can push the fifth arm 90 to extend from the fourth arm 80. At this time, the length of the third chain 112 between the third pulley 111 and the fifth arm 90 increases, and the length of the third chain 112 between the third pulley 111 and the third arm 30 decreases and pulls the fourth arm section. Thus, the third chain 112 can assist the fourth arm 80 to extend from the third arm 30, reducing the push-out load of the second-stage cylinder rod 101.

[0089] In this embodiment, such as Figure 2 As shown, the telescopic device also includes a fourth linkage component 120, which includes:

[0090] The fourth pulley 121 is mounted on the right end of the fourth section arm 80.

[0091] Fourth chain 122 ( Figure 2 (Only the portion of the fourth chain 122 between the fourth pulley 121 and the third arm 30 is shown.) One end of the fourth chain 122 is connected to the right end of the third arm 30. After the fourth chain 122 passes over the right end of the fourth pulley 121, the other end of the fourth chain 122 is connected to the left end of the fifth arm 90.

[0092] Specifically, when the second-stage cylinder rod 102 retracts, it can drive the fifth arm 90 to retract from the fourth arm 80. At this time, the length of the fourth chain 122 between the fourth pulley 121 and the fifth arm 90 is reduced, so the fourth chain 122 will push the fourth pulley 121 to the left, thereby driving the fourth arm 80 to retract into the third arm 30. This arrangement can reduce the retraction load of the second-stage cylinder rod 101.

[0093] In this embodiment, such as Figure 2 As shown, the telescopic device also includes:

[0094] The second distance sensor 130 is used to obtain the relative distance between the fifth arm 90 and the fourth arm 80.

[0095] Specifically, after obtaining the relative distance between the third arm 30 and the fourth arm 80, the relative positions of the third arm 30, the fourth arm 80 and the fifth arm 90 can be determined based on this relative distance.

[0096] In this embodiment, such as Figure 2 As shown, the second distance sensor 130 is a pull-wire sensor, which is located at the left end of the third arm 30, and the pull wire of the pull-wire sensor is connected to the left end of the fourth arm 80.

[0097] like Figure 2 As shown, the left ends of the third arm 30 and the fourth arm 80 are connected by a pull wire, resulting in a compact overall design. The relative positions of the third arm 30, fourth arm 80, and fifth arm 90 can be determined based on the length of the pull wire. Of course, those skilled in the art will understand that the distance sensor can also be other Time-of-Flight (TOF) sensors.

[0098] In this embodiment, the telescopic device further includes:

[0099] The controller (not shown in the figure) is configured as follows:

[0100] Based on the distance signals from the first distance sensor 70 and the second distance sensor 130, the first two-stage hydraulic cylinder 40 and the second two-stage hydraulic cylinder 100 are controlled to extend the third arm 30 and the fifth arm 90 proportionally from the second arm 20 and the fourth arm 80.

[0101] Specifically, after acquiring the distance signals from the first distance sensor 70 and the second distance sensor 130, the controller can obtain the relative positions of the first arm 10 to the fifth arm 90. Based on these relative positions, the controller adjusts the hydraulic pressure of the first two-stage hydraulic cylinder 40 and the second two-stage hydraulic cylinder 100 to achieve proportional extension of the third arm 30 and the fifth arm 90 from the second arm 20 and the fourth arm 80. With the assistance of the first linkage assembly 50 and the third linkage assembly 110, the extension movement of the second arm 20 to the fifth arm 90 can be ensured to be smooth without causing impact. Similarly, when the controller controls the third arm 30 and the fifth arm 90 to retract proportionally from the second arm 20 and the fourth arm 80 based on these relative positions, with the assistance of the second linkage assembly 60 and the fourth linkage assembly 120, the retraction movement of the second arm 20 to the fifth arm 90 can be ensured to be smooth without causing impact.

[0102] The present invention also discloses an aerial work platform vehicle, which includes the aforementioned telescopic device.

[0103] Clearly, this aerial work platform vehicle possesses all the technical benefits brought about by the aforementioned telescopic device, so it will not be elaborated upon here.

[0104] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0105] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A telescopic mechanism, characterized in that, The telescopic mechanism includes: The segmental arm includes a first segmental arm (10), a second segmental arm (20), and a third segmental arm (30) nested from the outside to the inside. The first two-stage hydraulic cylinder (40) is located inside the segment arm and includes a first-stage cylinder rod (41), a first-stage cylinder rod (42), and a first cylinder body (43). The first-stage cylinder rod (41) is connected to the first segment arm (10), the first-stage cylinder rod (42) is connected to the second segment arm (20), and the first cylinder body (43) is connected to the third segment arm (30). The first linkage component (50) is used to drive the second arm (20) away from the first arm (10) by moving away from the third arm (30) and the second arm (20). The telescopic mechanism further includes a second linkage component (60), which includes: The second pulley (61) is mounted on the right end of the second arm (20); The second chain (62) has one end connected to the right end of the first arm (10), and after the second chain (62) passes over the right end of the second pulley (61), the other end of the second chain (62) is connected to the left end of the third arm (30).

2. The telescopic mechanism according to claim 1, characterized in that, The first linkage component (50) includes: The first pulley (51) is mounted on the left end of the second arm (20); The first chain (52) has one end connected to the right end of the first arm (10), and after the first chain (52) passes around the left end of the first pulley (51), the other end of the first chain (52) is connected to the left end of the third arm (30).

3. The telescopic mechanism according to claim 1, characterized in that, The telescopic mechanism further includes: A first distance sensor (70) is used to obtain the relative distance between the first arm segment (10) and the second arm segment (20).

4. The telescopic mechanism according to claim 3, characterized in that, The first distance sensor (70) is a pull-wire sensor, which is located at the left end of the first arm (10), and the pull wire of the pull-wire sensor is connected to the left end of the second arm (20).

5. A telescopic device, characterized in that, The telescopic device includes the telescopic mechanism according to any one of claims 1 to 4.

6. The telescopic device according to claim 5, characterized in that, The telescopic device further includes: Fourth arm (80) and fifth arm (90); The second two-stage cylinder (100) includes a second first-stage cylinder rod (101), a second second-stage cylinder rod (102), and a second cylinder body (103). The second first-stage cylinder rod (101) is connected to the third arm (30); the second second-stage cylinder rod (102) is connected to the fourth arm (80); and the second cylinder body (103) is connected to the fifth arm (90). The third linkage component (110) is used to drive the fourth arm (80) away from the third arm (30) by moving away from the fifth arm (90) and the fourth arm (80).

7. The telescopic device according to claim 6, characterized in that, The telescopic device further includes: The second distance sensor (130) is used to obtain the relative distance between the fifth arm (90) and the fourth arm (80).

8. The telescopic device according to claim 7, characterized in that, The telescopic device further includes: The controller is configured as follows: Based on the distance signals from the first distance sensor (70) and the second distance sensor (130), the first two-stage hydraulic cylinder (40) and the second two-stage hydraulic cylinder (100) are controlled to push the third arm (30) and the fifth arm (90) out proportionally from the second arm (20) and the fourth arm (80).

9. An aerial work platform vehicle, characterized in that, The aerial work platform includes a telescopic device according to any one of claims 5 to 8.

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