Piston rod connecting device for telescopic arm oil cylinder of lorry-mounted crane
By using the design of connecting pipes and plugs in the piston rod connection device of the telescopic arm cylinder on the crane, the problem of difficulty in cleaning iron chips and complex process is solved, rapid detection and secondary pressure testing are achieved, and the reliability and service life of the oil cylinder are improved.
Patent Information
- Application Number
- CN202422456390.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-10
AI Technical Summary
In the prior art, there are problems such as difficulty in cleaning iron chips, complicated process and inability to perform secondary pressure tests during the detection of the piston rod of the telescopic arm cylinder of the crane.
The design of connecting pipe and plug is adopted, and rapid testing is achieved through the cooperation of connecting pipe and plug, which avoids flattening and cutting steps, ensures the reliability of the oil cylinder, and supports secondary pressure testing.
The inspection process is simplified, the generation of iron filings is avoided, and the service life and reliability of the oil cylinder are improved.
Smart Images
Figure CN223239641U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an oil cylinder, in particular to a piston rod connecting device for a telescopic arm oil cylinder of a truck-mounted crane. Background Art
[0002] The piston rod of the telescopic boom cylinder of a truck-mounted crane is an actuator of the hydraulic system. It uses hydraulic oil as the working medium and is mainly composed of a hollow piston rod 5, an oil pipe 3, a rod head 1, a piston 6, a guide sleeve 8, a cylinder body 7 and a seal. The two ends of the oil pipe 3 are welded to the hollow piston rod 5 and the rod head 1 respectively.
[0003] like Figure 3 and Figure 4 As shown, the oil pipe 3 is made of welded seamless steel pipe. Therefore, in order to ensure reliability under high pressure, it is necessary to test whether the oil pipe 3 is leaking after the rod head 1 and the oil pipe 3 are welded. The current detection method is to set a closed section 31 at the end of the oil pipe 3 away from the rod head 1, flatten the closed section 31, and then fully weld it. Then, high-pressure hydraulic oil is introduced through the second oil hole 12 of the rod head 1 to detect whether there is leakage in the oil pipe 3 and between the oil pipe 3 and the rod head 1. After the detection is completed, the flattened closed section 31 of the oil pipe 3 is cut off, and the oil pipe 3 retains the required length.
[0004] This approach has the following problems:
[0005] 1. Because there is hydraulic oil in the oil pipe, iron chips can easily stick to the oil pipe through the hydraulic oil after the oil pipe is cut, making it difficult to clean the iron chips completely. There are hidden dangers and it will affect the service life of the oil cylinder.
[0006] 2. The test has many steps, including flattening, welding, and cutting, which makes the process complicated and time-consuming.
[0007] 3. After the welding of the hollow piston rod, rod head and piston is completed, a secondary pressure test is required. However, since the other end of the oil pipe is in an open state, the secondary pressure test cannot be carried out. Utility Model Content
[0008] In order to solve the above problems of difficulty in cleaning iron chips, complicated testing process and inability to perform secondary pressure test, the utility model provides a piston rod connecting device for the telescopic arm cylinder of a truck-mounted crane. The specific technical solution is as follows:
[0009] A piston rod connecting device for a telescopic boom oil cylinder of a truck-mounted crane comprises: a hollow piston rod; a rod head provided with a first oil hole and a second oil hole, the rod head being provided at one end of the hollow piston rod, the first oil hole being communicated with the hollow piston rod; an oil pipe provided in the hollow piston rod, one end of the oil pipe being provided on the rod head and communicating with the second oil hole; and a connecting pipe, one end of which is provided at the other end of the oil pipe, the other end of which is provided with a threaded hole and connected to the other end of the hollow piston rod.
[0010] Preferably, the threaded hole is a sealing tube threaded hole.
[0011] Compared with the prior art, the present invention has the following beneficial effects:
[0012] The utility model provides a piston rod connecting device for the telescopic arm cylinder of a truck-mounted crane, which realizes rapid testing through a connecting pipe in conjunction with a plug, without the need for flattening, welding, and cutting, greatly reducing the process steps and without generating iron filings, effectively ensuring the service life of the cylinder, and enabling secondary pressure testing through the plug, further improving the overall reliability of the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a schematic diagram of the structure of this application;
[0014] Figure 2 yes Figure 1 A partial enlarged view of point I in the middle;
[0015] Figure 3 It is a structural diagram of the prior art;
[0016] Figure 4 yes Figure 3 A partial enlarged view of point II in the middle. DETAILED DESCRIPTION
[0017] The present invention will now be further described with reference to the accompanying drawings.
[0018] like Figure 1 and Figure 2 As shown, a piston rod connection device for a telescopic boom cylinder of a truck-mounted crane comprises a hollow piston rod 5, a rod head 1, an oil pipe 3, and a connecting pipe 4. The rod head 1 is provided with a first oil hole 11 and a second oil hole 12. The rod head 1 is seal-welded to one end of the hollow piston rod 5, and the hollow piston rod 5 is also in communication with the first oil hole 11. The oil pipe 3 is located inside the hollow piston rod 5, and one end of the oil pipe 3 is seal-welded to the rod head 1, and the oil pipe 3 is also in communication with the second oil hole 12. One end of the connecting pipe 4 is seal-welded to the other end of the oil pipe 3, and the other end of the connecting pipe 4, away from the oil pipe 3, is provided with a threaded hole 41. The other end of the connecting pipe 4 is also seal-welded to the hollow piston rod 5.
[0019] When testing is performed after the rod head 1 and oil pipe 3 are welded, a plug is installed in the threaded hole 41. The plug seals the end of the oil pipe 3, eliminating the need for flattening, welding, and cutting. The plug is quick and easy to install and remove, greatly improving testing efficiency and shortening testing time. It also eliminates the generation of iron filings, effectively ensuring the service life of the oil cylinder. Because the end of the oil pipe 3 away from the rod head 1 can be sealed by the plug, a secondary pressure test can be performed even after the hollow piston rod 5, rod head 1, connecting pipe 4, and oil pipe 3 are welded together, greatly improving the reliability of the piston rod.
[0020] The wall thickness of the connecting pipe 4 is greater than that of the oil pipe 3 , which can ensure that the connecting pipe 4 itself does not leak while ensuring strength, facilitating the processing of the threaded hole 41 , and ensuring the reliability of the connection between the plug and the threaded hole 41 .
[0021] When the rod head 1, the oil pipe 3, the hollow piston rod 5 and the oil pipe 3 are welded and tested, the plug is installed on the threaded hole 41 to perform a secondary pressure test.
[0022] In order to improve the sealing performance between the plug and the threaded hole 41, the threaded hole 41 is a sealing pipe threaded hole. The sealing pipe thread is convenient for disassembly and assembly and has good sealing performance.
[0023] The telescopic arm cylinder of the truck crane also includes a cylinder body 7, a guide sleeve 8, and a piston 6. A piston hole is provided inside the cylinder body 7, which is a blind hole. The guide sleeve 8 is fixed to the end of the cylinder body 7, and the piston 6 is slidably inserted into the piston hole. The piston 6 is threadedly connected to the outer circular surface of the hollow piston rod 5 and is located at the end of the hollow piston rod 5 away from the rod head 1.
[0024] When the cylinder body 7 is extended, oil enters the second oil hole 12, and the hydraulic oil enters the first cavity 21 of the oil pipe 3. The hydraulic oil enters the fourth cavity 24 of the cylinder body 7 through the first cavity 21, and then pushes the cylinder body 7 to extend. The hydraulic oil in the third cavity 23 composed of the piston 6, the hollow piston rod 5, the guide sleeve 8 and the cylinder body 7 enters the second cavity 22 between the hollow piston rod 5 and the oil pipe 3 through the connecting hole 51 on the hollow piston rod 5, and then enters the first oil hole 11 through the second cavity 22. The hydraulic oil is discharged from the first oil hole 11.
[0025] When the cylinder body 7 retracts, oil enters the first oil hole 11, and the hydraulic oil enters the third cavity 23 through the second cavity 22 and the connecting hole 51, and then pushes the cylinder body 7 to retract through the guide sleeve 8. The hydraulic oil in the fourth cavity 24 enters the second oil hole 12 through the first cavity 21, and the hydraulic oil is discharged from the second oil hole 12.
[0026] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and should not be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the claims of the present invention.
Claims
1. A piston rod connecting device for a telescopic boom cylinder of a truck-mounted crane, characterized in that: include: Hollow piston rod (5); A rod head (1) is provided with a first oil hole (11) and a second oil hole (12), the rod head (1) being provided at one end of the hollow piston rod (5), the first oil hole (11) being in communication with the hollow piston rod (5); An oil pipe (3) is provided in the hollow piston rod (5), one end of the oil pipe (3) is provided on the rod head (1) and communicates with the second oil hole (12); and A connecting pipe (4) has one end disposed at the other end of the oil pipe (3), and the other end is provided with a threaded hole (41) and is connected to the other end of the hollow piston rod (5).
2. The piston rod connecting device for the telescopic arm cylinder of a truck-mounted crane according to claim 1, characterized in that: The threaded hole (41) is a sealing pipe threaded hole.