Multi-stage cylinder telescopic arm for lifting and truck crane using the telescopic arm

Abstract

The present invention first provides a multi-stage cylinder telescopic arm for lifting, so as to solve the problem that in the process of synchronous telescopic extension of traditional telescopic arms, when the boom is extended to a shorter length, the fourth telescopic arm with the smallest end strength is also extended synchronously and participates in the force, and each stage of the telescopic arm must participate in the synchronous telescopic action, which increases the wear of the end telescopic arm and other related parts. When the multi-stage telescopic arm is extended, the telescopic arms at each stage are extended in sequence, which is different from the traditional synchronous extension. Driven by the multi-stage hydraulic cylinder, the boom starts from the first telescopic arm when extending the arm. After each arm is fully extended, the lower arm begins to extend until all the booms are extended in sequence. When the lifting operation does not require a longer boom, the second and third telescopic arms with smaller end strength will no longer extend or will be partially extended, which maximizes the load-bearing capacity and safety factor of the boom and reduces the wear of the telescopic parts related to the end arm.

Description

Technical Field

[0001] The invention relates to a lifting arm, in particular to a lifting multi-stage cylinder telescopic arm and a truck crane using the telescopic arm. Background Art

[0002] With the changes in the market, the demand for small-tonnage truck cranes is increasing. At present, the telescopic action of the lifting arm of medium and small truck cranes produced in my country generally adopts the telescopic mechanism of the "single-cylinder rope system", such as the Chinese patent: Truck-mounted crane single-cylinder with three sets of cable arm synchronous telescopic system, patent number CN1020205132273, publication date May 11, 2021.

[0003] like Figure 1 As shown in the figure, the synchronous telescopic boom has a fixed boom in the first section and telescopic booms in the second, third and fourth sections. These telescopic booms are "synchronously extended and retracted" in any case. When this type of boom is fully extended, the entire boom is close to the "single cantilever equal strength beam" structure and is in a more reasonable balanced stress state. However, when the boom is extended for a shorter period of time, the fourth telescopic boom with the smallest end strength also extends synchronously and participates in the stress, which will undoubtedly reduce the safety factor of the maximum lifting force. Moreover, regardless of the length of the boom, the telescopic arms at all levels must participate in the synchronous telescopic action, which increases the wear of the end telescopic arm and other related parts. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention first provides a multi-stage cylinder telescopic arm for lifting, so as to solve the problem that when the lifting arm is extended shorter during the synchronous extension and retraction process of the traditional telescopic arm, the fourth section of the telescopic arm with the smallest end strength is also extended synchronously and participates in the force, and the telescopic arms at all levels must participate in the synchronous extension and retraction action, which increases the wear of the last section of the telescopic arm and other related components.

[0005] The technical solution is as follows: it comprises a fixed arm, which is slidably sleeved with a first telescopic arm, and also comprises a last telescopic arm, which is slidably sleeved in the first telescopic arm; the last telescopic arm is connected to the first telescopic arm or through the second telescopic arm, the last telescopic arm is slidably sleeved in the second telescopic arm, and the second telescopic arm is slidably sleeved in the first telescopic arm; it also comprises a built-in multi-stage hydraulic cylinder, which is an asynchronous telescopic structure at each stage, and which extends or retracts a cylinder body and a piston in sequence under the action of pressure oil, and comprises a fixed cylinder fixedly connected to a pin shaft at the end of the fixed arm, and a multi-stage telescopic cylinder corresponding to each telescopic arm is nested in the fixed cylinder, wherein the last telescopic arm corresponds to the piston rod in the last telescopic cylinder body, and the last telescopic arm is driven by the piston rod to telescope, forming a structure in which the corresponding telescopic cylinder drives the corresponding telescopic arm to telescope.

[0006] In the above or some embodiments, a locking ring is fixedly provided at the end of each telescopic cylinder, and the locking ring is fixed to the corresponding telescopic arm by a steel cable, forming a structure in which the telescopic cylinder drives the telescopic arm to extend through the locking ring and the steel cable; the multi-stage telescopic cylinder includes a terminal telescopic cylinder, and a hydraulic oil port is provided on the cylinder body of the terminal telescopic cylinder, and the telescopic cylinders of each stage are driven to retract by the inflow of hydraulic oil.

[0007] In the above or some embodiments, the locking ring includes a first locking ring and a second locking ring, the first and second locking rings include an annular portion fixedly connected to the telescopic cylinder, the annular portion of the first locking ring is fixedly provided with a first connecting rod for fixing to the steel cable, one end of the corresponding first steel cable is fixedly connected to the first connecting rod, the other end of the first steel cable is fixedly connected to the second connecting rod, the second connecting rod is fixedly connected to the ear plate fixed to the inner surface of the telescopic arm by an adjusting bolt, forming a structure that the adjusting bolt can adjust the tightness of the first steel cable; the annular portion of the second locking ring and the first and second connecting rods of the first locking ring are provided with a raised portion for fixing the steel cable on the same side, the diameter of the raised portion is larger than the diameter of the connection point of the first connecting rod, forming a structure that the corresponding second steel cable can be distributed on both sides of the first steel cable, and the other end of the second steel cable is fixedly connected to the corresponding inner wall of the telescopic arm through the third connecting rod by an adjusting bolt.

[0008] In the above or some embodiments, the end of the piston rod corresponding to the last telescopic arm is connected to the internal pin of the last telescopic arm through a pin.

[0009] In the above or some embodiments, it also includes a support wheel group arranged on the circumference of the telescopic cylinder body or the circumference of the annular part, the support wheel group is composed of a plurality of support wheels with supports, each of the supports is fixedly mounted on the cylinder body surface or the circumference of the annular part, each support is rotatably connected to the corresponding support wheel, and the wheel body of the support wheel group forms a structure that is in close contact with the inner surface of the last section of the telescopic arm, forming a structure in which the multi-stage hydraulic cylinder is supported by the inner side surface of the last section of the telescopic arm.

[0010] The present invention also provides a truck crane to solve the problem that when the boom is extended short during the synchronous extension and retraction of the traditional telescopic arm, the fourth telescopic arm with the smallest end strength is also extended synchronously and participates in the force, and all telescopic arms at all levels must participate in the synchronous extension and retraction action, which increases the wear of the last telescopic arm and other related parts. The truck crane described in this solution adopts the multi-stage cylinder telescopic arm disclosed in this technical solution.

[0011] When the patent is used, when the multi-stage telescopic arm is extended, each stage of the telescopic arm is extended in sequence, which is different from the traditional synchronous extension. Driven by the multi-stage hydraulic cylinder, the boom starts from the first section of the telescopic arm when it is extended. After each section of the arm is fully extended, the lower section of the arm begins to extend until all the booms are extended in sequence. When the lifting operation does not require a longer boom, the second and third sections of the telescopic arm with lower end strength will no longer extend or will be partially extended, which maximizes the load-bearing capacity and safety factor of the boom and reduces the wear of the telescopic parts related to the end arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of a synchronous telescopic arm in the prior art.

[0013] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention.

[0014] Figure 3 It is a structural schematic diagram of the multi-stage hydraulic cylinder in the present invention.

[0015] Figure 4 It is a schematic diagram of the first steel cable and the first telescopic arm, and the second steel cable and the second telescopic arm in the present invention.

[0016] Figure 5 It is a schematic diagram of the telescopic arm structure of the present invention.

[0017] Figure 6 It is a schematic diagram of the use of the telescopic arm extended in the present invention. DETAILED DESCRIPTION

[0018] The specific implementation manner is further described in detail below in conjunction with the accompanying drawings.

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Those skilled in the art will appreciate that directional terms such as “upper”, “lower”, “outer” and “inner” are descriptive terms for the drawings and do not represent limitations on the scope of protection defined in the claims.

[0021] like Figure 1-3As shown, the technical solution is that it includes a fixed arm 101, the fixed arm 101 is slidably sleeved with a first telescopic arm 102, and also includes a terminal telescopic arm 103, the terminal telescopic arm 103 is slidably sleeved in the first telescopic arm 102; the terminal telescopic arm 103 is connected to the first telescopic arm 102 or through a second telescopic arm 104, the terminal telescopic arm 103 is slidably sleeved in the second telescopic arm 104, and the second telescopic arm 104 is slidably sleeved in the first telescopic arm 102; it also includes a built-in multi-stage hydraulic cylinder 200, the multi-stage The hydraulic cylinder 200 is a multi-stage asynchronous telescopic structure. The multi-stage hydraulic cylinder 200 extends or retracts the cylinder body and the piston rod 204 in sequence under the action of the pressure oil. The multi-stage hydraulic cylinder 200 includes a fixed cylinder 201 fixedly connected to the end pin shaft of the fixed arm 101, and a multi-stage telescopic cylinder corresponding to each section of the telescopic arm is nested in the fixed cylinder 201, wherein the last section of the telescopic arm 103 corresponds to the piston rod 204 in the last section of the telescopic cylinder body, and the piston rod 204 drives the last section of the telescopic arm 103 to be telescoped, forming a structure in which the corresponding telescopic cylinder drives the corresponding section of the telescopic arm to be telescoped.

[0022] In the above-mentioned embodiment, the fixed arm 101 refers to the arm body connected to the vehicle body, and its function is to be able to adjust the vertical angle relative to the vehicle body, but it cannot be extended; the function of each level of telescopic arm is to be able to extend or retract relative to the part to which it is directly connected. In this technical solution, the fixed arm 101 and the telescopic arm are both provided with a cavity that cooperates with the lower and telescopic arms to form a sliding sleeve structure. When the telescopic arm is three-section, the last telescopic arm is the third telescopic arm, and when the telescopic arm is two-section, the last telescopic arm is the second telescopic arm 104.

[0023] In one embodiment, the telescopic arm includes three sections of telescopic arms, including a first section of the telescopic arm 102, a second section of the telescopic arm 104, and a third section of the telescopic arm (the last section of the telescopic arm). At this time, the built-in multi-stage hydraulic cylinder 200 includes a fixed cylinder 201 corresponding to the fixed arm 101, a first-stage telescopic cylinder 202 corresponding to the first section of the telescopic arm 102, a second-stage telescopic cylinder 203 corresponding to the second section of the telescopic arm 104, and a piston rod 204 corresponding to the third-stage telescopic arm.

[0024] In the above or some embodiments, the locking ring 300 includes a first locking ring 301 and a second locking ring 302 , and the first and second locking rings 300 include an annular portion 303 that is fixedly connected to the telescopic cylinder.

[0025] A pin sleeve is provided at the rear end of the fixed cylinder 201, which is connected to the fixed arm 101 through a pin shaft. The support wheel group 600 relies on the inner wall of the third telescopic arm and bears the deadweight of the oil cylinder; the support wheel group 600 includes a support wheel group 600 welded on the surface of the cylinder body of the fixed cylinder 201, and also includes a support wheel group 600 welded on the locking ring 300 at the end of the second telescopic cylinder 203, which also relies on the inner wall of the third telescopic arm and shares the deadweight of the oil cylinder when it is extended and retracted. The built-in multi-stage hydraulic oil cylinder 200 has a tendency to sag downward under the action of its own weight due to its deadweight and must be sleeved inside the fourth telescopic arm. The setting of the support wheel group 600 can effectively prevent the multi-stage hydraulic oil cylinder 200 from sagging, especially when the third telescopic arm is extended to the limit position, it can also effectively prevent the oil cylinder from sagging. The pin sleeve at the front end of the piston rod 204 is connected and fixed to the third telescopic arm through a pin shaft.

[0026] The annular portion 303 of the first locking ring 301 is fixedly provided with a first connecting rod 401 for fixing with a steel cable, one end of the corresponding first steel cable 400 is fixedly connected to the first connecting rod 401, the other end of the first steel cable 400 is fixedly connected to the second connecting rod 402, and the second connecting rod 402 is fixedly connected to the ear plate fixed to the inner surface of the telescopic arm through an adjusting bolt 403, forming a structure in which the adjusting bolt 403 can adjust the tightness of the first steel cable 400;

[0027] The first cable 400 is provided with two adjustment bolts at the end. Figure 3 As shown, the first steel cable 400 is fastened to two ear plates at the end of the inner cavity of the first telescopic arm, and the front end of the first steel cable 400 is fastened to the annular portion 303 of the first locking ring 301 through a first connecting rod 401 .

[0028] A raised portion 501 for fixing the steel cable is provided on the same side of the annular portion 303 of the second locking ring 302 and the first and second connecting rods of the first locking ring 301. The diameter of the raised portion 501 is larger than the diameter of the connection point of the first connecting rod 401, forming a structure in which the corresponding second steel cable 500 can be distributed on both sides of the first steel cable 400. The other end of the second steel cable 500 is fixedly connected to the inner wall of the corresponding telescopic arm through the third connecting rod through the adjusting bolt 403.

[0029] The second cable 500 is adjusted by four adjustment bolts at the end. Figure 3 As shown, the two ear plates fastened to the inner end of the second telescopic arm 104 , the front end of the arm rope is sleeved in the tensioning wheel ring groove formed by the protrusions 501 on both sides of the second locking ring 302 .

[0030] In the above or some embodiments, a locking ring 300 is fixedly provided at the end of each telescopic cylinder, and the locking ring 300 is fixed to the corresponding telescopic arm by a steel cable, forming a structure in which the telescopic cylinder drives the telescopic arm to extend through the locking ring 300 and the steel cable; the multi-stage telescopic cylinder includes a terminal telescopic cylinder, and a hydraulic oil port is provided on the cylinder body of the terminal telescopic cylinder, and the hydraulic oil flowing in drives the telescopic cylinders of each stage to retract.

[0031] When the boom is extended, the hydraulic oil enters from the A port of the fixed cylinder 201, and first drives the first-stage telescopic cylinder 202 with the largest cylinder cross-sectional area and the largest thrust to start working, driving the first steel cable 400 to link the first telescopic arm 102 to extend. When the stroke of the first-stage telescopic cylinder 202 ends, the first telescopic arm 102 is fully extended. At this time, the second-stage telescopic cylinder 203 with the second cylinder cross-sectional area starts working, driving the second steel cable 500 to link the second telescopic arm 104 to extend. When the stroke of the second telescopic arm 104 ends, the second telescopic arm 104 is fully extended. At this time, the piston rod 204 with the smallest cylinder cross-sectional area starts working, and directly pushes the third telescopic arm to extend through the pin sleeve and pin shaft at the front end of the piston rod 204. When the stroke of the piston rod 204 ends, the third telescopic arm is fully extended. At this time, the "sequential extension" action of each telescopic arm is completed, and the entire lifting arm is fully extended to the maximum length.

[0032] When the arm is retracted, oil is introduced from the B port of the second-stage telescopic cylinder 203, firstly driving its piston rod 204 to retract and drive the third telescopic arm to retract. When the return stroke of the piston rod 204 is terminated, the third telescopic arm is fully retracted and its end contacts the end of the "three-section arm". At the same time, the return oil circuit of the first telescopic cylinder is also opened. At this time, the first telescopic cylinder together with the superimposed pulling force of the second-stage telescopic cylinder 203 pulls the third telescopic arm to retract through the end of the third telescopic arm. When the return stroke of the first-stage telescopic cylinder 202 is terminated, the third telescopic arm is fully retracted and its end contacts the end of the first telescopic arm 102. At this time, the return oil circuit of the fixed cylinder 201 is also opened, together with the superimposed pulling force of the first-stage telescopic cylinder 202 and the second-stage telescopic cylinder 203, pulls the first telescopic arm 102 and the second telescopic arm 104 to retract through the end of the third telescopic arm. When the return stroke of the fixed cylinder 201 is terminated, the retraction of the entire boom is completed.

[0033] Driven by the "multi-stage cylinder", the boom starts to extend from the first telescopic boom 102, and the lower boom begins to extend after each boom is fully extended, until all the booms are extended in sequence. When the lifting operation does not require a longer boom, the second and third telescopic booms with lower end strength will not be extended, or will be partially extended, which maximizes the load-bearing capacity and safety factor of the boom and reduces the wear of the telescopic parts related to the end boom.

[0034] In the above or some embodiments, it also includes a support wheel group 600 arranged on the circumference of the telescopic cylinder body or the circumference of the annular portion 303, and the support wheel group 600 is composed of a plurality of support wheels 602 with supports 601, each of the supports 601 is fixedly installed on the cylinder body surface or the circumference of the annular portion 303, and each support 601 is rotatably connected to the corresponding support wheel 602, and the wheel body of the support wheel group 600 forms a structure that is in close contact with the inner surface of the last section of the telescopic arm 103, forming a structure in which the multi-stage hydraulic cylinder 200 is supported by the inner side surface of the last section of the telescopic arm 103.

[0035] The present invention also provides a truck crane to solve the problem that when the boom is extended short during the synchronous extension and retraction of the traditional telescopic arm, the fourth telescopic arm with the smallest end strength is also extended synchronously and participates in the force, and all telescopic arms at all levels must participate in the synchronous extension and retraction action, which increases the wear of the last telescopic arm and other related parts. The truck crane described in this solution adopts the multi-stage cylinder telescopic arm disclosed in this technical solution.

[0036] When the patent is used, when the multi-stage telescopic arm is extended, each stage of the telescopic arm is extended in sequence, which is different from the traditional synchronous extension. Driven by the multi-stage hydraulic cylinder, the boom starts from the first telescopic arm 102 when it is extended. After each arm is fully extended, the lower arm begins to extend until all the booms are extended in sequence. When the lifting operation does not require a longer boom, the second and third telescopic arms with smaller end strength will no longer extend or will be partially extended, which maximizes the load-bearing capacity and safety factor of the boom and reduces the wear of the telescopic parts related to the end arm.

Claims

1. A multi-stage cylinder telescopic arm for lifting, comprising a fixed arm (101), the fixed arm being an arm body connected to a vehicle body and being non-retractable; the fixed arm (101) being slidably sleeved with a first telescopic arm (102), and further comprising a final telescopic arm (103), the final telescopic arm (103) being slidably sleeved in the first telescopic arm (102); the final telescopic arm (103) being connected to the first telescopic arm (102) or through a second telescopic arm (104), the final telescopic arm (103) being slidably sleeved in the second telescopic arm (104), the second telescopic arm (104) being slidably sleeved in the first telescopic arm (102); and further comprising a built-in multi-stage hydraulic oil cylinder (200), the multi-stage hydraulic oil cylinder (200) The invention is a multi-stage asynchronous telescopic structure. The multi-stage hydraulic cylinder (200) extends or retracts the cylinder body and the piston rod (204) in sequence under the action of pressure oil. The multi-stage hydraulic cylinder (200) comprises a fixed cylinder (201) fixedly connected to a pin shaft at the end of a fixed arm (101). The fixed cylinder (201) is embedded with a multi-stage telescopic cylinder corresponding to each section of the telescopic arm. The last section of the telescopic arm (103) corresponds to the piston rod (204) in the last section of the telescopic cylinder. The last section of the telescopic arm (103) is driven to telescope by the piston rod (204), forming a structure in which the corresponding telescopic cylinder drives the corresponding section of the telescopic arm to telescope. A locking ring (300) is fixedly provided at the end of each of the telescopic cylinders. The locking ring (300) is fixed to the corresponding telescopic arm by a steel cable. , forming a structure in which the telescopic cylinder drives the telescopic arm to extend through the locking ring (300) and the steel cable; the multi-stage telescopic cylinder comprises a terminal telescopic cylinder, the cylinder body of the terminal telescopic cylinder is provided with a hydraulic oil port, and the hydraulic oil flowing into the cylinder drives the telescopic cylinders of each stage to retract; the locking ring (300) comprises a first locking ring (301) and a second locking ring (302), the first and second locking rings comprise an annular portion (303) sleeved and fixed to the telescopic cylinder, the annular portion (303) of the first locking ring (301) is fixedly provided with a first connecting rod (401) for fixing to the steel cable, one end of the corresponding first steel cable (400) is fixedly connected to the first connecting rod, and the other end of the first steel cable (400) is fixedly connected to the second connecting rod (402), the The second connecting rod (402) is fixedly connected to the ear plate fixed to the inner surface of the telescopic arm via an adjusting bolt (403), forming a structure in which the adjusting bolt (403) can adjust the tightness of the first steel cable (400); a protrusion (501) for fixing the second steel cable (500) is provided on the same side of the annular portion (303) of the second locking ring (302) and the first and second connecting rods of the first locking ring (301), the diameter of the protrusion (501) being larger than the diameter of the connection portion of the first connecting rod (401), forming a structure in which the corresponding second steel cables (500) are distributed on both sides of the first steel cable (400), and the other end of the second steel cable (500) is fixedly connected to the inner wall of the corresponding telescopic arm via the third connecting rod via the adjusting bolt (403).

2. The multi-stage cylinder telescopic arm for lifting according to claim 1, characterized in that: The end of the piston rod (204) corresponding to the last telescopic arm is connected to the internal pin of the last telescopic arm via a pin.

3. The multi-stage cylinder telescopic arm for lifting according to claim 2, characterized in that: The invention also comprises a support wheel group (600) arranged on the circumference of the telescopic cylinder body or the circumference of the annular portion (303), wherein the support wheel group (600) is composed of a plurality of support wheels (602) with supports (601), each of the supports (601) being fixedly mounted on the surface of the cylinder body or the circumference of the annular portion (303), each of the supports (601) being rotatably connected to a corresponding support wheel (602), and the wheel body of the support wheel group (600) forms a structure in close contact with the inner surface of the last telescopic arm (103), thereby forming a structure in which the multi-stage hydraulic cylinder (200) is supported by the inner surface of the last telescopic arm (103).

4. Truck crane, characterized in that: It comprises a multi-stage cylinder telescopic arm for lifting as described in any one of claims 1-3.

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