A multi-segment tubular guide rail

Abstract

The present invention discloses a multi - section tubular guide rail, which includes a fixed part and a telescopic part. The fixed part is slidably connected to the telescopic part. It further includes a load - bearing support part. One side of the load - bearing support part is connected to the upper part of the telescopic part, and the other side of the load - bearing support part is slidably connected to the upper part of the fixed part. The fixed part and the telescopic part are tubular. A fixed - part cage is arranged inside the fixed part, and fixed - part balls are arranged on the fixed - part cage. A telescopic - part ball groove is arranged at a position corresponding to the fixed - part cage outside the telescopic part, and the fixed - part balls are adapted to the telescopic - part ball groove. Through the above design, the guide rail of the present invention is not easy to sway left and right, has a high load - bearing capacity, is simple to install, has low requirements for dimensions, has smooth sliding, and has the function of preventing sand and dust from entering.

Description

Technical Field

[0001] The present invention relates to the technical field of guide rails, and particularly to a multi-section tubular guide rail. Background Art

[0002] A guide rail is a workpiece that can carry objects and reciprocate telescopically. The guide rails on the market basically adopt the design of C-shaped bending or cold bending forming, and are generally installed on both sides of the box when in use. However, this design scheme will cause the guide rail to swing left and right easily when extending outwards, and the load-bearing capacity of the guide rail is low, resulting in greater installation difficulty of the guide rail, higher dimensional requirements, and easy unsmooth sliding. On the other hand, the transmission components in this design scheme are generally exposed outside, resulting in easy entry of dust and sand, and over time, it is easy to cause the guide rail to be unable to telescopic, reducing the service life. Therefore, improvements need to be made. Summary of the Invention

[0003] In view of the defects in the prior art that the guide rail is easy to swing left and right, has a low load-bearing capacity, has a greater installation difficulty, has higher dimensional requirements, is easy to slide unsmoothly, and the components are exposed outside, the present invention provides a new multi-section tubular guide rail.

[0004] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0005] A multi-section tubular guide rail includes a fixed part and a telescopic part. The fixed part is slidably connected to the telescopic part, and further includes a load-bearing support part. One side of the load-bearing support part is connected to the upper part of the telescopic part, and the other side of the load-bearing support part is slidably connected to the upper part of the fixed part. The fixed part and the telescopic part are tubular. A fixed part cage is arranged inside the fixed part, and fixed part balls are arranged on the fixed part cage. A telescopic part ball groove is arranged outside the telescopic part corresponding to the position of the fixed part cage, and the fixed part balls are adapted to the telescopic part ball groove.

[0006] The fixed part and the telescopic part are used to form the main structure of the guide rail. The bottom installation design makes the installation of the guide rail more intuitive, thus making the installation of the guide rail simpler and also reducing the dimensional requirements of the guide rail for the carrier. The load-bearing support part is used to assist in bearing the load, making the force on the fixed part and the telescopic part more uniform, thereby improving the load-bearing capacity of the guide rail. The fixed part and the telescopic part are tubular, which also prevents dust and sand from entering, makes the telescopic of the guide rail more stable, reduces left and right swinging, and also makes the installation of the guide rail simpler. The fixed part cage is used to install the fixed part balls, making the rolling of the fixed part balls smoother. The fixed part balls are adapted to the telescopic part ball groove, enabling the guide rail to slide and telescope through the fixed part balls, thereby making the telescopic of the guide rail smoother and more stable. Through the above design, the present invention makes the guide rail not easy to swing left and right, has a high load-bearing capacity, is simple to install, has low dimensional requirements, slides smoothly, and has the function of preventing dust and sand from entering.

[0007] Preferably, for the multi-segment tubular guide rail described above, the telescopic part includes a middle rail and an inner rail. The fixed part, the middle rail, and the inner rail are slidably connected in sequence. A middle rail cage is arranged inside the middle rail, middle rail balls are arranged on the middle rail cage, an inner rail ball groove is arranged outside the inner rail at a position corresponding to the middle rail cage, the middle rail balls are adapted to the inner rail ball groove, a telescopic part support seat is arranged at the front part of the inner rail, and the lower part of the telescopic part support seat is flush with the lower part of the fixed part. Sealing sheets are arranged at the ends of the fixed part, the middle rail, and the inner rail.

[0008] The middle rail and the inner rail are used to form the main structure of the telescopic part. The middle rail cage is used to install the middle rail balls to make the rolling of the middle rail balls smoother. The middle rail balls are adapted to the inner rail ball groove, so that the middle rail and the inner rail slide and telescope through the middle rail balls, making the telescoping of the guide rail smoother and more stable. The lower part of the telescopic part support seat is flush with the lower part of the fixed part, which is used to assist in bearing weight after the guide rail is fully retracted, making the force on the guide rail more uniform, thus increasing the load-bearing capacity of the guide rail and making the guide rail not easy to swing. Each sealing sheet plays a sealing role to prevent dust and sand from entering the inside of the guide rail, making the sealing effect of the guide rail better. At the same time, the outside of the sealing sheet can be wrapped with sealant. The sealant is relatively soft. When the guide rail expands and contracts, the sealant can scrape off the dust and sand on the surface of the guide rail without affecting the sliding of the guide rail. The sealant can be designed with protrusions to be more conducive to scraping off dust and sand. The sealing sheet can be installed by screws.

[0009] Preferably, for the multi-segment tubular guide rail described above, the number of middle rails is not less than 2, and the middle rails are slidably connected to each other.

[0010] The number of middle rails is not less than 2, and the middle rails are slidably connected to each other, and are respectively slidably connected to the fixed part and the inner rail at both ends, enabling the guide rail to be applicable to carriers of various sizes, improving the applicability of the guide rail, and further reducing the size requirements of the guide rail for the carrier. The sliding connection can be specifically achieved by balls for sliding connection.

[0011] Preferably, for the multi-segment tubular guide rail described above, the fixed part, the telescopic part, and the load-bearing support part are made of aluminum alloy material or carbon fiber material.

[0012] The fixed part, the telescopic part, and the load-bearing support part are made of aluminum alloy material or carbon fiber material, which not only ensures the strength of the guide rail but also reduces the weight of the guide rail itself, thus meeting the lightweight requirements in the fields of military, aerospace, rail transit, etc.

[0013] Preferably, for a multi - section tubular guide rail as described above, an extending limit stop is provided on the inner surface of the front part of the fixed part, a retracting limit stop is provided on the inner surface of the rear part of the fixed part, a telescopic part limit stop is provided on the rear part of the telescopic part, and the telescopic part limit stop is respectively adapted to the extending limit stop and the retracting limit stop.

[0014] The telescopic part limit stop is respectively adapted to the extending limit stop and the retracting limit stop, which not only limits the extending and retracting distance range of the telescopic part, but also makes the structure of the telescopic part more stable after extension or retraction, thereby further increasing the load - bearing capacity of the guide rail.

[0015] Preferably, for a multi - section tubular guide rail as described above, it further includes a motor and a lead screw assembly. The motor is connected to the rear part of the fixed part, a handwheel is provided on one side of the motor, one end of the lead screw assembly passes through the fixed part and is connected to the motor, the other end of the lead screw assembly is connected to the inside of the telescopic part, an extending limit switch is provided on the inner surface of the front part of the fixed part, a retracting limit switch is provided on the inner surface of the rear part of the fixed part, and the extending limit switch and the retracting limit switch are respectively electrically connected to the motor.

[0016] The motor is used to drive the lead screw assembly, and the lead screw assembly is used to link the telescopic part, enabling the guide rail to have an automatic telescopic function. The handwheel is used to manually control the rotation of the motor, thereby controlling the lead screw assembly, so that the guide rail can be telescoped by operating the handwheel in case of power failure. The retracting limit switch is used to send an electrical signal and stop the operation of the motor when the guide rail automatically retracts to the position of the retracting limit switch, and the extending limit switch is used to send an electrical signal and stop the operation of the motor when the guide rail automatically extends to the position of the extending limit switch. Both make the automatic telescopic function of the guide rail require less manual control, thus making the use of the automatic telescopic function of the guide rail simpler. On the other hand, the guide rail adopts a tubular design, which saves more space when setting up motor - related components.

[0017] Preferably, for a multi - section tubular guide rail as described above, a middle - rail limit stop is provided on the inner surface of the front part of the middle rail, and an inner - rail limit stop is provided on the outer surface of the rear part of the inner rail, and the middle - rail limit stop is adapted to the inner - rail limit stop.

[0018] The middle - rail limit stop is adapted to the inner - rail limit stop. When the inner rail extends to the limit, the inner - rail limit stop is linked with the middle - rail limit stop, enabling the inner rail to drive the middle rail to continue to extend, so that the telescoping of the guide rail is more orderly, further improving the stability of the guide rail.

[0019] Preferably, for a multi - section tubular guide rail as described above, it further includes a positioning support. A T - shaped convex part is provided on the upper part of the fixed part, the positioning support is adapted to the T - shaped convex part, and the upper part of the positioning support is connected to the lower part of the load - bearing support part.

[0020] The positioning support is adapted to the T-shaped convex part, which not only makes the connection of the load-bearing support part more firm, but also restricts the sliding direction of the load-bearing support part, so that the load-bearing support part is not easy to swing and the sliding of the load-bearing support part is more stable. On the other hand, the positioning support is connected to the lower part of the load-bearing support part, so that there is a gap between the positioning support and the T-shaped convex part, thus not affecting the sliding of the load-bearing support part.

[0021] Preferably, for a multi-section tubular guide rail as described above, a bearing groove is provided on the upper part of the fixed part, a bearing is provided in the bearing groove, and the upper part of the bearing abuts against the lower part of the load-bearing support part.

[0022] The bearing is used to realize the sliding of the load-bearing support part, making the sliding of the load-bearing support part smoother. The bearing is located in the bearing groove, making the force on the bearing more uniform, thereby improving the load-bearing capacity of the guide rail.

[0023] Preferably, for a multi-section tubular guide rail as described above, an extending bead device is provided on the inner surface of the front part of the fixed part, a retracting bead device is provided on the inner surface of the rear part of the fixed part, a bead groove is provided on the middle rail, and the bead groove is respectively adapted to the extending bead device and the retracting bead device.

[0024] The bead groove is respectively adapted to the extending bead device and the retracting bead device, so that the middle rail can be assisted and fixed when it is at the position of the extending bead device and the position of the retracting bead device, thereby further strengthening the structural stability when the guide rail extends and retracts. At the same time, the bead groove and the extending bead device or the retracting bead device can be separated in terms of force, thus not affecting the telescopic function of the guide rail. Especially when the guide rail expands and contracts, the middle rail is assisted and fixed by the extending bead device or the retracting bead device, so its position remains unchanged, always keeping the inner rail moving first, and driving the middle rail to expand and contract after the inner rail completes its expansion and contraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Structural schematic diagram of the present invention Figure 1 ;

[0026] Figure 2 Structural schematic diagram of the present invention Figure 2 ;

[0027] Figure 3 Structural schematic diagram of the present invention Figure 3 ;

[0028] Figure 4 is Figure 3 partial enlarged view of part A in

[0029] Figure 5 Structural schematic diagram of the present invention Figure 4 ;

[0030] Figure 6 is Figure 5 a partial enlarged view of part B in

[0031] Figure 7 a structural schematic diagram of the present invention Figure 5 ;

[0032] Figure 8 a structural schematic diagram of the present invention Figure 6 ;

[0033] Figure 9 a structural schematic diagram of the present invention Figure 7 ;

[0034] Figure 10 is Figure 9 a partial enlarged view of part C in

[0035] Figure 11 is Figure 9 a partial enlarged view of part D in

[0036] Figure 12 a structural schematic diagram of the present invention Figure 8 ;

[0037] Figure 13 is Figure 12 a partial enlarged view of part E in

[0038] Figure 14 is Figure 12 a partial enlarged view of part F in

[0039] Figure 15 is Figure 12 a partial enlarged view of part G in Specific embodiments

[0040] The present invention will be further described in detail below in conjunction with the appended Figures 1 - 15 drawings and specific embodiments, but they are not limitations to the present invention:

[0041] Embodiment 1

[0042] A multi - section tubular guide rail includes a fixed part 4 and a telescopic part 3. The fixed part 4 is slidably connected to the telescopic part 3. It further includes a load - bearing support part 2. One side of the load - bearing support part 2 is connected to the upper part of the telescopic part 3, and the other side of the load - bearing support part 2 is slidably connected to the upper part of the fixed part 4. The fixed part 4 and the telescopic part 3 are tubular. A fixed - part cage 41 is arranged in the fixed part 4, and fixed - part balls 42 are arranged on the fixed - part cage 41. A telescopic - part ball groove 31 is arranged at a position corresponding to the fixed - part cage 41 outside the telescopic part 3. The fixed - part balls 42 are adapted to the telescopic - part ball groove 31.

[0043] The fixed part 4 and the telescopic part 3 are slidably connected through the fixed part ball 42. When the guide rail extends, the telescopic part 3 and the load-bearing support part 2 slide outwards. When the guide rail retracts, the telescopic part 3 and the load-bearing support part 2 slide inwards. The guide rail is installed at the bottom, and the carrier is installed on the upper part of the load-bearing support part 2.

[0044] The guide rail is in two sections, four sections or more than four sections: when the guide rail retracts, the length of the load-bearing support part 2 is longer than the length after the fixed part 4 and the telescopic part 3 retract, so a bending structure is provided, such as Figure 1 、 Figure 2 shown. The bending structure may include a hinge on the load-bearing support part 2, a top plate wheel on the fixed part 4, and a top wheel seat on the telescopic part 3, such as Figure 1 、 Figure 3 shown. When in use, first extend the telescopic part 3, such as Figure 1 shown. Then install the carrier on the load-bearing support part 2. When it needs to retract, first remove the carrier, and then retract the telescopic part 3. When retracting the telescopic part 3, the top wheel seat abuts against the top plate wheel to act, causing the load-bearing support part 2 with the hinge to bend, so that the telescopic part 3 can continue to retract.

[0045] The guide rail is in three sections: when the guide rail retracts, the length of the load-bearing support part 2 is equal to the length after the fixed part 4 and the telescopic part 3 retract, so there is no need to set a bending structure, such as Figure 7 、 Figure 8 shown. Thus, when in use, the telescoping of the guide rail does not affect the disassembly and assembly of the carrier.

[0046] Preferably, the telescopic part 3 includes a middle rail 32 and an inner rail 33. The fixed part 4, the middle rail 32, and the inner rail 33 are slidably connected in sequence. A middle rail cage 321 is arranged inside the middle rail 32. Middle rail balls 322 are arranged on the middle rail cage 321. Inner rail ball grooves 331 are arranged outside the inner rail 33 at positions corresponding to the middle rail cage 321. The middle rail balls 322 are adapted to the inner rail ball grooves 331. A telescopic part support seat 34 is arranged at the front of the inner rail 33. The lower part of the telescopic part support seat 34 is flush with the lower part of the fixed part 4. Sealing sheets 5 are arranged at the ends of the fixed part 4, the middle rail 32, and the inner rail 33.

[0047] At this time, the guide rail is in three sections, and the fixed part 4, the middle rail 32, and the inner rail 33 are slidably connected in sequence. The sliding connection can be specifically achieved by balls. After the guide rail retracts completely, the telescopic part support seat 34 and the fixed part 4 jointly abut against the ground. Sealing sheets 5 are arranged between the fixed part 4, the middle rail 32, and the inner rail 33, as well as at the rear end of the fixed part 4 and the front end of the inner rail 33. The outside of the sealing sheet 5 can be wrapped with sealant. The sealant can be designed with protrusions, which is more conducive to scraping off dust and sand. The sealing sheet 5 can be installed by screws.

[0048] Preferably, the number of the middle rails 32 is not less than two, and the middle rails 32 are slidably connected to each other.

[0049] At this time, the guide rail has four or more sections. The middle rails are slidably connected to each other, and both ends are respectively slidably connected to the fixed part and the inner rail. The sliding connection can be specifically achieved by means of balls.

[0050] Preferably, the fixed part 4, the telescopic part 3, and the load-bearing support part 2 are made of aluminum alloy material or carbon fiber material.

[0051] The fixed part 4, the telescopic part 3, and the load-bearing support part 2 can be formed by extrusion of aluminum alloy or carbon fiber.

[0052] Preferably, an extended limit stop 43 is provided on the inner surface of the front part of the fixed part 4, a retracted limit stop 49 is provided on the inner surface of the rear part of the fixed part 4, a telescopic part limit stop 36 is provided on the rear part of the telescopic part 3, and the telescopic part limit stop 36 is respectively adapted to the extended limit stop 43 and the retracted limit stop 49.

[0053] When the guide rail extends, the telescopic part 3 extends, the telescopic part limit stop 36 is separated from the retracted limit stop 49, and the telescopic part 3 extends until the telescopic part limit stop 36 abuts against the extended limit stop 43, and the extension process ends. The extended limit stop 43 restricts the further extension of the telescopic part 3.

[0054] When the guide rail retracts, the telescopic part 3 retracts, the telescopic part limit stop 36 is separated from the extended limit stop 43, and the telescopic part 3 retracts until the telescopic part limit stop 36 abuts against the retracted limit stop 49, and the retraction process ends. The retracted limit stop 49 restricts the further retraction of the telescopic part 3.

[0055] Preferably, it further includes a motor 1 and a lead screw assembly 11. The motor 1 is connected to the rear part of the fixed part 4. A handwheel 12 is provided on one side of the motor 1. One end of the lead screw assembly 11 passes through the fixed part 4 and is connected to the motor 1, and the other end of the lead screw assembly 11 is connected to the inside of the telescopic part 3. An extended limit switch 13 is provided on the inner surface of the front part of the fixed part 4, and a retracted limit switch 14 is provided on the inner surface of the rear part of the fixed part 4. The extended limit switch 13 and the retracted limit switch 14 are respectively electrically connected to the motor 1.

[0056] The guide rail has two sections: When the guide rail needs to extend, start motor 1. Motor 1 drives the telescopic part 3 to extend through the lead screw assembly 11. The telescopic part 3 simultaneously drives the load-bearing support part 2 to slide. During the extension process, when the rear part of the telescopic part 3 touches the extension limit switch 13, the extension limit switch 13 sends an electrical signal to motor 1 to stop the operation of motor 1, thus ending the extension process. When the guide rail needs to retract, start motor 1. Motor 1 drives the telescopic part 3 to retract through the lead screw assembly 11. The telescopic part 3 simultaneously drives the load-bearing support part 2 to slide. During the retraction process, when the rear part of the telescopic part 3 touches the retraction limit switch 14, the retraction limit switch 14 sends an electrical signal to motor 1 to stop the operation of motor 1, thus ending the retraction process.

[0057] The guide rail has three or more sections: When the guide rail needs to extend, start motor 1. Motor 1 drives the inner rail 33 to extend through the lead screw assembly 11. The inner rail 33 simultaneously drives the load-bearing support part 2 to slide and also drives one or more middle rails 32 to slide. During the extension process, when the rear part of the middle rail 32 closest to the fixed part 4 touches the extension limit switch 13, the extension limit switch 13 sends an electrical signal to motor 1 to stop the operation of motor 1, thus ending the extension process. When the guide rail needs to retract, start motor 1. Motor 1 drives the inner rail 33 to retract through the lead screw assembly 11. The inner rail 33 simultaneously drives the load-bearing support part 2 to slide and also drives one or more middle rails 32 to slide. During the retraction process, when the rear part of the middle rail 32 closest to the fixed part 4 touches the retraction limit switch 14, the retraction limit switch 14 sends an electrical signal to motor 1 to stop the operation of motor 1, thus ending the retraction process.

[0058] When the guide rail is equipped with a telescopic part limit stop 36, an extension limit stop 43, and a retraction limit stop 49, the extension limit stop 43 can be set at the same position as the extension limit switch 13, and the retraction limit stop 49 can be set at the same position as the retraction limit switch 14. When the extension limit switch 13 or the retraction limit switch 14 sends an electrical signal, the corresponding extension limit stop 43 or retraction limit stop 49 restricts the further extension or retraction of the guide rail to prevent inertial displacement.

[0059] Preferably, a middle rail limit stop 323 is provided on the inner surface of the front part of the middle rail 32, and an inner rail limit stop 332 is provided on the outer surface of the rear part of the inner rail 33. The middle rail limit stop 323 is adapted to the inner rail limit stop 332.

[0060] The guide rail has three sections: When the guide rail extends, the inner rail 33 is driven by the lead screw assembly 11 to extend first. During the extension process, the inner rail limit stop 332 touches the middle rail limit stop 323, causing the inner rail 33 to continue driving the middle rail 32 to extend. The inner rail 33 always takes the lead.

[0061] The guide rail has four or more sections: a limiting stop block structure is sequentially arranged between each middle rail. When the guide rail extends, the inner rail 33 is first driven to extend by the lead screw assembly 11. During the extension process, the inner rail limiting stop block 332 abuts against the middle rail limiting stop block 323, causing the inner rail 33 to continue driving the middle rail 32 closest to the lead screw assembly 11 to extend, and then the middle rail 32 closest to the lead screw assembly 11 continues to drive the next middle rail 32, and each middle rail 32 extends in sequence. The inner rail 33 always advances first.

[0062] Preferably, it further includes a positioning support 21. A T-shaped convex part 44 is arranged on the upper part of the fixing part 4. The positioning support 21 is adapted to the T-shaped convex part 44, and the upper part of the positioning support 21 is connected to the lower part of the load-bearing support part 2.

[0063] The positioning support 21 is adapted to the T-shaped convex part 44 to limit the sliding direction of the load-bearing support part 2. The positioning support 21 is connected to the lower part of the load-bearing support part 2, so that there is a gap between the positioning support 21 and the T-shaped convex part 44, thus not affecting the sliding of the load-bearing support part 2.

[0064] Preferably, a bearing groove 45 is arranged on the upper part of the fixing part 4, a bearing 46 is arranged in the bearing groove 45, and the upper part of the bearing 46 abuts against the lower part of the load-bearing support part 2.

[0065] The load-bearing support part 2 slides through the bearing 46. The bearing 46 is arranged in the bearing groove 45 and is connected to the inner wall of the bearing groove 45 at both ends, and the force is evenly distributed.

[0066] Preferably, an extending bead device 47 is arranged on the inner surface of the front part of the fixing part 4, a retracting bead device 48 is arranged on the inner surface of the rear part of the fixing part 4, a bead groove 35 is arranged on the middle rail 32, and the bead groove 35 is respectively adapted to the extending bead device 47 and the retracting bead device 48.

[0067] When the guide rail needs to extend, the inner rail 33 extends, and the bead groove 35 on the middle rail 32 is assisted and fixed by the retracting bead device 48. After the inner rail 33 finishes extending and continues to drive the middle rail 32 to slide, the bead groove 35 and the retracting bead device 48 are separated by force. At the end of the extension process, the bead groove 35 is just assisted and fixed by the extending bead device 47. When the guide rail needs to retract, the inner rail 33 retracts. After the inner rail 33 finishes retracting and continues to drive the middle rail 32 to slide, the bead groove 35 and the extending bead device 47 are separated by force. At the end of the retraction process, the bead groove 35 is just assisted and fixed by the retracting bead device 48.

[0068] In short, the above are only the preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A multi - section tubular guide rail, comprising a fixed part (4) and a telescopic part (3), wherein the fixed part (4) is slidably connected to the telescopic part (3). Characterized in that: It further comprises a load - bearing support part (2). One side of the load - bearing support part (2) is connected to the upper part of the telescopic part (3), and the other side of the load - bearing support part (2) is slidably connected to the upper part of the fixed part (4). The fixed part (4) and the telescopic part (3) are tubular. A fixed - part cage (41) is arranged inside the fixed part (4), and fixed - part balls (42) are arranged on the fixed - part cage (41). A telescopic - part ball groove (31) is arranged outside the telescopic part (3) corresponding to the position of the fixed - part cage (41), and the fixed - part balls (42) are adapted to the telescopic - part ball groove (31).

2. A multi - section tubular guide rail according to claim 1, Characterized in that: The telescopic part (3) comprises a middle rail (32) and an inner rail (33). The fixed part (4), the middle rail (32), and the inner rail (33) are slidably connected in sequence. A middle - rail cage (321) is arranged inside the middle rail (32), and middle - rail balls (322) are arranged on the middle - rail cage (321). An inner - rail ball groove (331) is arranged outside the inner rail (33) corresponding to the position of the middle - rail cage (321), and the middle - rail balls (322) are adapted to the inner - rail ball groove (331). A telescopic - part support seat (34) is arranged at the front part of the inner rail (33), and the lower part of the telescopic - part support seat (34) is flush with the lower part of the fixed part (4). Sealing sheets (5) are arranged at the ends of the fixed part (4), the middle rail (32), and the inner rail (33).

3. A multi - section tubular guide rail according to claim 2, Characterized in that: The number of the middle rails (32) is not less than 2, and the middle rails (32) are slidably connected to each other.

4. A multi - section tubular guide rail according to claim 1, Characterized in that: The fixed part (4), the telescopic part (3), and the load - bearing support part (2) are made of aluminum alloy material or carbon fiber material.

5. A multi - section tubular guide rail according to claim 1, Characterized in that: An extending limit stop block (43) is arranged on the inner surface of the front part of the fixed part (4), a retracting limit stop block (49) is arranged on the inner surface of the rear part of the fixed part (4), a telescopic - part limit stop block (36) is arranged at the rear part of the telescopic part (3), and the telescopic - part limit stop block (36) is respectively adapted to the extending limit stop block (43) and the retracting limit stop block (49).

6. A multi - section tubular guide rail according to any one of claims 1 - 5, Characterized in that: It further includes a motor (1) and a lead screw assembly (11). The motor (1) is connected to the rear part of the fixed part (4). A handwheel (12) is arranged on one side of the motor (1). One end of the lead screw assembly (11) passes through the fixed part (4) and is connected to the motor (1), and the other end of the lead screw assembly (11) is connected to the inside of the telescopic part (3). An extension limit switch (13) is arranged on the inner surface of the front part of the fixed part (4), and a retraction limit switch (14) is arranged on the inner surface of the rear part of the fixed part (4). The extension limit switch (13) and the retraction limit switch (14) are electrically connected to the motor (1) respectively.

7. A multi-section tubular guide rail according to claim 2, characterized in that: A middle rail limit stop (323) is arranged on the inner surface of the front part of the middle rail (32), and an inner rail limit stop (332) is arranged on the outer surface of the rear part of the inner rail (33). The middle rail limit stop (323) is adapted to the inner rail limit stop (332).

8. A multi-section tubular guide rail according to claim 1, characterized in that: It further includes a positioning support (21). A T-shaped convex part (44) is arranged on the upper part of the fixed part (4). The positioning support (21) is adapted to the T-shaped convex part (44), and the upper part of the positioning support (21) is connected to the lower part of the load-bearing support part (2).

9. A multi-section tubular guide rail according to claim 1, characterized in that: A bearing groove (45) is arranged on the upper part of the fixed part (4), and a bearing (46) is arranged in the bearing groove (45). The upper part of the bearing (46) abuts against the lower part of the load-bearing support part (2).

10. A multi-section tubular guide rail according to claim 2, characterized in that: An extension bead device (47) is arranged on the inner surface of the front part of the fixed part (4), and a retraction bead device (48) is arranged on the inner surface of the rear part of the fixed part (4). A bead groove (35) is arranged on the middle rail (32). The bead groove (35) is adapted to the extension bead device (47) and the retraction bead device (48) respectively.

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