Hydraulic cylinder, piston anti-loosening structure thereof and engineering machinery

Abstract

The utility model discloses a hydraulic cylinder, a piston anti-loosening structure of the hydraulic cylinder and engineering machinery. The hydraulic cylinder comprises a piston rod, a piston, at least one perforation pin shaft and a fastener, the piston is assembled at the end part of the piston rod in a threaded manner; at least one perforation pin shaft is inserted into a groove between the opposite circumferential surfaces of the piston rod and the piston and is used for limiting radial rotation between the piston rod and the piston; the fastener is installed on the axial end face, close to the perforation pin shaft, of the piston rod and used for pressing the perforation pin shaft and preventing the perforation pin shaft from axially moving. The anti-loosening device can achieve the anti-loosening effect under the working condition of high-frequency vibration.

Description

Technical Field

[0001] The utility model relates to a hydraulic cylinder piston anti-loosening structure and belongs to the technical field of hydraulic cylinders. Background Art

[0002] During the operation of the hydraulic cylinder, the piston rod reciprocates under high pressure. The piston is subjected to repeated hydraulic shocks from frequent high-pressure hydraulic oil. The stress at the threaded connection changes under high pressure. When the piston rod is fully extended and retracted, the piston thread connection loosens or even falls off due to the fast speed and contact shocks of varying degrees. This causes a series of failure problems such as internal leakage in the hydraulic cylinder, seal damage, and piston falling off. Therefore, solving the problem of loose threads on the hydraulic cylinder piston rod is one of the key contents of hydraulic cylinder technology. In many working conditions, such as shield machines and excavators, hydraulic cylinders not only have to work under vibration conditions, but also for a long time because they sometimes need to blast mountains and drill rocks. Vibration is a major cause of thread failure. Equipment under such working conditions generally requires a long service life. Because the loss of downtime for maintenance is immeasurable, a hydraulic cylinder piston anti-loosening structure is needed to achieve anti-loosening.

[0003] Prior art 1: A common anti-loosening method is to drill a set screw on the end face to prevent loosening. The piston rod thread is screwed into place, and after tightening, a screw hole is drilled and the set screw is tightened to prevent loosening.

[0004] Prior art 2: Hydraulic cylinder piston anti-loosening technology uses a piston, hexagonal nut, offset screw, steel ball and piston rod combined anti-loosening structure. The nut is prevented from loosening by limiting the steel ball through the V-shaped annular groove of the piston rod, the offset threaded holes on the six sides of the hexagonal nut and the set screw.

[0005] However, the above-mentioned prior art has the following deficiencies:

[0006] Existing solution 1: Anti-loosening is achieved by drilling set screws at the threaded joints of the piston and piston rod. First tighten the threads, then drill the threaded holes to install the screws. Iron chips cannot be completely cleaned up, and iron chips entering the thread gap will cause disassembly. In the subsequent use, there is a risk of iron chips falling out and contaminating the hydraulic system under the impact of oil. At the same time, it is often subject to space constraints. There is not enough space for drilling after tightening the threads, and the drilling process is difficult.

[0007] Prior art 2: The piston rod is processed with a V-shaped annular groove, and the piston or nut is processed with a top screw hole, and radial top screws are used to prevent loosening. This method cannot completely prevent the piston rod thread and the piston from rotating relative to each other, and the piston will gradually loosen, causing the top screw to gradually withdraw and fail. Summary of the invention

[0008] In order to overcome the deficiencies of the above-mentioned prior art, the utility model provides a hydraulic cylinder piston anti-loosening structure, which can meet the anti-loosening effect under high-frequency vibration conditions.

[0009] The utility model is implemented according to the following technical solutions:

[0010] In the first aspect, the utility model provides a hydraulic cylinder piston anti-loosening structure, comprising a piston rod, a piston, at least one saddle pin and a fastener; the piston is assembled on the end of the piston rod in a threaded manner; at least one saddle pin is inserted into a groove between the facing circumferential surfaces of the piston rod and the piston, for limiting the radial rotation between the piston rod and the piston; the fastener is installed on the axial end face of the piston rod close to the saddle pin, for suppressing the saddle pin to prevent the saddle pin from axial movement.

[0011] In some embodiments, a semicircular groove extending axially inward is provided at the inner thread of the axial end face of the piston, and a semicircular groove extending axially inward is provided at the outer thread of the axial end face of the piston rod; after the piston is screwed into the piston rod, the two semicircular grooves are aligned to form a circular groove, and the saddle pin is inserted into the circular groove.

[0012] In some embodiments, two, three or four semicircular grooves are evenly spaced along the circumferential direction at the internal thread of the axial end face of the piston, which together with the semicircular grooves on the piston rod form two, three or four circular grooves.

[0013] In some embodiments, the saddle pin shaft is configured as a flat head structure or is provided with an axial threaded hole on the end surface facing outward.

[0014] In some embodiments, the axial end face of the piston rod is provided with a threaded hole extending axially inward near the saddle pin; the fastener is a flat head screw, consisting of a threaded rod and a flat head, and the threaded rod is screwed into the threaded hole until the flat head presses the saddle pin.

[0015] In some embodiments, the axial end face of the piston rod is provided with a fastener installation groove, and the groove for installing the saddle pin and the hole for installing the fastener both fall into the fastener installation groove, so that the head of the fastener after pressing the saddle pin falls completely into the fastener installation groove.

[0016] In some embodiments, the radial cross-section of the fastener mounting groove is an n-shaped structure for matching the circular head of the fastener.

[0017] In a second aspect, the utility model provides a hydraulic cylinder, comprising a cylinder body, in which the above-mentioned hydraulic cylinder piston anti-loosening structure is installed.

[0018] In a third aspect, the utility model provides an engineering machine equipped with the above-mentioned hydraulic cylinder.

[0019] Beneficial effects of the utility model:

[0020] The utility model adopts a pre-processed piston, a semicircular groove of the piston rod + an axial saddle pin + a flat head screw to form a combined anti-loosening structure, which is easy to process, and the saddle pin is used to fill the groove to limit the relative rotation between the piston rod and the piston, thereby achieving the thread anti-loosening effect. It avoids the problem of difficult cleaning of iron filings caused by drilling the saddle top screw hole + tightening the saddle top screw. Through the above scheme, the anti-loosening effect can be achieved under high-frequency vibration conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation on the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0022] In the attached picture:

[0023] Figure 1 It is a partial cross-sectional view of a hydraulic cylinder equipped with a hydraulic cylinder piston anti-loosening structure;

[0024] Figure 2 The side view and the front partial sectional view of the piston rod of the utility model (a is the side view, b is the front partial sectional view);

[0025] Figure 3 The side view and the front sectional view of the piston of the utility model (a is the side view, b is the front sectional view);

[0026] Figure 4 Schematic diagram of the saddle pin and flat head screw of the utility model (a is the saddle pin, b is the flat head screw).

[0027] Figure identification: 1-piston rod, 2-piston, 3-saddle pin, 4-flat head screw, 5-flat head screw mounting groove, 6-semicircular groove, 7-threaded hole.

[0028] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. The following embodiments are used to illustrate the utility model but are not used to limit the scope of the utility model.

[0030] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] As a common component in hydraulic systems, hydraulic cylinders are actuators that convert hydraulic energy into mechanical energy and perform linear reciprocating motion. Since the hydraulic cylinder is accompanied by severe vibrations during operation and the cylinder itself is subjected to frequent reciprocating high-pressure shocks, the piston is very easy to loosen. Over time, the piston thread will fail, causing the hydraulic cylinder to fall off, causing the entire machine to fail to work, bringing inconvenience to construction work, and in serious cases, causing safety accidents. As a very important actuator, the anti-loosening effect of the thread is one of the important factors affecting the stability of the hydraulic cylinder.

[0033] like Figure 1 As shown, the utility model provides a hydraulic cylinder piston anti-loosening structure, comprising a piston rod 1, a piston 2, at least one saddle pin 3 and a fastener; the piston 2 is assembled on the end of the piston rod 1 in a threaded manner; at least one saddle pin 3 is inserted into a groove between the facing circumferential surfaces of the piston rod 1 and the piston 2, for limiting the radial rotation between the piston rod 1 and the piston 2; the fastener is installed on the axial end surface of the piston rod 1 close to the saddle pin 3, for suppressing the saddle pin 3 to prevent the saddle pin 3 from axial movement.

[0034] The above-mentioned piston is further described below.

[0035] like Figure 3 , Figure 4As shown, a semicircular groove 6 extending axially inward is provided at the internal thread of the axial end face of the piston 2, and a semicircular groove 6 extending axially inward is provided at the external thread of the axial end face of the piston rod 1; after the piston 2 is screwed into the piston rod 1, until the piston 2 is tightened on the piston rod 1 and the two semicircular grooves 6 are aligned to form a circular groove, the saddle pin 3 is inserted into the circular groove.

[0036] From the above, it can be seen that pre-processing the semicircular grooves of the piston and piston rod can avoid the problem of difficult cleaning of iron chips in the post-processing saddle threaded holes; the saddle pin is easy to install and disassemble, and at the same time can withstand greater force to prevent the thread from rotating, thereby improving the stability and safety of the threaded connection, not prone to failure, and can meet the requirements of complex vibration working conditions.

[0037] According to a preferred solution, two, three or four semicircular grooves 6 are evenly spaced along the circumferential direction at the internal thread of the axial end face of the piston 2, which together with the semicircular grooves 6 on the piston rod 1 form two, three or four circular grooves; since the semicircular grooves 6 are evenly distributed on the piston 2 and the piston rod 1 after pre-processing, the piston 2 is tightened to the bottom on the piston rod 1 and matched with the closest semicircular grooves. As long as one is matched into a circular groove, the remaining ones will naturally be matched into circular grooves, and finally a saddle pin 3 is installed in each circular groove.

[0038] It should be noted that the number of semicircular grooves is not limited to the above, and can be modified accordingly according to the design requirements.

[0039] In a preferred solution, the end surface of the saddle pin 3 facing outward is configured as a flat head structure or is provided with an axial threaded hole to facilitate disassembly of the saddle pin 3.

[0040] It should be noted that the style of the saddle pin can be varied and is not limited to the above structure.

[0041] The above-mentioned piston rod is further described below.

[0042] like Figure 2 , Figure 4 As shown, the axial end face of the piston rod 1 is provided with a threaded hole 7 extending axially inward near the saddle pin 3; the fastener is a flat head screw 4, which consists of a threaded rod and a flat head, and the threaded rod is screwed into the threaded hole 7 until the flat head presses the saddle pin 3.

[0043] From the above, it can be seen that the utility model adopts a combined anti-loosening structure composed of a pre-processed piston, a semicircular groove of the piston rod + an axial saddle pin + a flat head screw stop. According to the above design, the function of preventing the piston rod thread from loosening can be achieved, and at the same time, the problem of insufficient space for drilling holes during post-processing of the saddle screw holes and difficulty in cleaning the drilled iron chips after the piston is tightened can be avoided.

[0044] Further solutions, such as Figure 1 , Figure 2 As shown, the axial end face of the piston rod 1 is provided with a flat head screw mounting groove 5, and the semicircular groove 6 for mounting the saddle pin 3 and the threaded hole 7 for mounting the flat head screw 4 both fall into the flat head screw mounting groove 5, so that the head of the flat head screw 4 after pressing the saddle pin 3 completely falls into the flat head screw mounting groove 5.

[0045] The preferred solution is Figure 2 As shown, the radial cross-section of the flat head screw installation groove 5 is an n-shaped structure, which is used to match the round head of the flat head screw 4.

[0046] The working principle of the hydraulic cylinder piston anti-loosening structure of the utility model is as follows:

[0047] like Figure 1 As shown, evenly distributed semicircular grooves 6 are processed at the thread of the end face of the piston 2, and evenly distributed semicircular grooves 6 are processed at the thread of the end face of the piston rod 1. The end face of the piston rod 1 is also processed with a flat head screw installation groove 5 and a threaded hole 7. After the piston 2 is tightened onto the piston rod 1, it is pre-tightened to match the two semicircular grooves 6 into a circular groove position, and a saddle pin 3 is installed in each circular groove, and the flat head screw 4 is tightened to prevent the saddle pin 3 from withdrawing. The circular groove is filled with the saddle pin 3 to limit the relative rotation between the piston rod 1 and the piston 2, thereby achieving the thread anti-loosening effect. At the same time, in order to prevent the saddle pin 3 from withdrawing, the end face of the piston rod 1 is processed with a threaded hole and a flat head screw 4 is installed, thereby achieving the purpose of preventing the piston 2 from loosening. By adopting a combined anti-loosening structure composed of a pre-processed piston, a semicircular groove of the piston rod + an axial saddle pin + a flat head screw stop, it is easy to process, avoids the problem of difficult cleaning of iron filings caused by drilling the saddle top screw hole + tightening the saddle top screw, significantly improves the anti-loosening effect, and has very good stability during use.

[0048] The utility model also provides a hydraulic cylinder, comprising a cylinder body, in which the hydraulic cylinder piston anti-loosening structure is installed.

[0049] The utility model also provides an engineering machine equipped with the hydraulic cylinder.

[0050] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0051] In addition, those skilled in the art will understand that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments also means being within the scope of protection of the present utility model and forming different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by the present application.

[0052] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as a preferred embodiment as above, it is not used to limit the utility model. Any technician familiar with this patent can make some changes or modify the technical content suggested above into an equivalent embodiment with equivalent changes without departing from the scope of the technical solution of the utility model. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the content of the technical solution of the utility model still falls within the scope of the solution of the utility model.

Claims

1. A hydraulic cylinder piston anti-loosening structure, characterized in that: include: A piston rod and a piston, wherein the piston is threadedly assembled on the end of the piston rod; At least one saddle pin, inserted into the groove between the facing circumferential surfaces of the piston rod and the piston, for limiting radial rotation between the piston rod and the piston; The fastener is installed on the axial end face of the piston rod close to the saddle pin and is used to suppress the saddle pin to prevent the saddle pin from moving axially.

2. The hydraulic cylinder piston anti-loosening structure according to claim 1, characterized in that: A semicircular groove extending axially inwards is provided at the internal thread of the axial end surface of the piston, and a semicircular groove extending axially inwards is provided at the external thread of the axial end surface of the piston rod; After the piston is screwed onto the piston rod, the piston is screwed onto the piston rod until the two semicircular grooves are aligned to form a circular groove, and the saddle pin is inserted into the circular groove.

3. The anti-loosening structure of a hydraulic cylinder piston according to claim 2, characterized in that: The inner thread of the axial end face of the piston is evenly and alternately provided with two, three or four semicircular grooves along the circumferential direction, which together with the semicircular grooves on the piston rod form two, three or four circular grooves.

4. The hydraulic cylinder piston anti-loosening structure according to claim 1, characterized in that: The end surface of the saddle pin shaft facing outward is configured as a flat head structure or is provided with an axial threaded hole.

5. The hydraulic cylinder piston anti-loosening structure according to claim 1, characterized in that: The axial end surface of the piston rod is provided with a threaded hole extending axially inward near the saddle pin; The fastener is a flat head screw, which consists of a threaded rod and a flat head. The threaded rod is screwed into the threaded hole until the flat head presses the saddle pin.

6. The hydraulic cylinder piston anti-loosening structure according to claim 1, characterized in that: The axial end face of the piston rod is provided with a fastener installation groove, and the groove for installing the saddle pin and the hole for installing the fastener both fall into the fastener installation groove, so that the head of the fastener after pressing the saddle pin completely falls into the fastener installation groove.

7. The hydraulic cylinder piston anti-loosening structure according to claim 6, characterized in that: The radial cross section of the fastener installation groove is an n-shaped structure, which is used to match the circular head of the fastener.

8. A hydraulic cylinder, comprising a cylinder body, characterized in that: The cylinder body is installed with the hydraulic cylinder piston anti-loosening structure according to any one of claims 1 to 7.

9. An engineering machine, characterized in that: The hydraulic cylinder according to claim 8 is installed.

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