Lifting hydraulic cylinder with built-in safety valve for hydraulic slip

Abstract

The utility model discloses a lifting hydraulic cylinder with a built-in safety valve for a hydraulic slip, which relates to the field of hydraulic cylinder devices for hydraulic slips, and specifically comprises a cylinder body, a lifting cylinder, a safety valve, a lifting cylinder, a lifting cylinder and a lifting cylinder body, and the cylinder body is internally provided with a cavity with an opening at one end; the piston end of the piston rod is located in the cavity and makes contact with the inner wall of the cavity in a sealed mode. The safety valve is mounted at the piston end of the piston rod; the sealing piece is installed on the piston rod, and the outer wall of the sealing piece makes contact with the inner wall of the cavity to form sealing; the at least two oil ports are formed in the cylinder body at intervals, and the oil ports are communicated with the cavity. The hydraulic cylinder for the hydraulic slip solves the technical problem that an existing hydraulic cylinder for the hydraulic slip cannot quickly release pressure.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic cylinder devices for hydraulic slips, in particular to a lifting hydraulic cylinder for hydraulic slips with a built-in safety valve. Background Art

[0002] A hydraulic slip is a mechanical device for clamping a drill string during tripping operations in oil drilling. The actions of clamping or releasing the drill string are driven by two lifting hydraulic cylinders. To limit the maximum clamping force and ensure the safe use of the equipment, a safety relief valve is generally provided in the hydraulic circuit, and this safety valve is connected to the lifting hydraulic cylinder through a hydraulic pipeline.

[0003] When the load of the lifting hydraulic cylinder increases and the pressure in its working oil chamber reaches the set pressure of the safety valve, the safety valve opens and starts to relieve pressure. Since the hydraulic pipeline connecting the lifting hydraulic cylinder and the safety valve has a certain length and its diameter is small due to the limitation of the installation space, the working oil pressure of the lifting hydraulic cylinder often exceeds the set pressure of the safety valve. Especially when the load of the lifting hydraulic cylinder increases instantaneously, since the safety valve is too late to relieve pressure, the lifting hydraulic cylinder outputs a clamping force far higher than the set value, resulting in damage to the clamped drill string or the body structure of the hydraulic slip. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a lifting hydraulic cylinder for hydraulic slips with a built-in safety valve, which solves the technical problem that the hydraulic cylinder for hydraulic slips cannot relieve pressure quickly.

[0005] The embodiment of the present application discloses a lifting hydraulic cylinder for hydraulic slips with a built-in safety valve, including:

[0006] A cylinder block, in which a cavity with one end open is provided;

[0007] A piston rod, the piston end of which is located inside the cavity and contacts and closes the inner wall of the cavity;

[0008] A safety valve, installed at the piston end of the piston rod;

[0009] A seal, installed on the piston rod, and the outer wall of the seal contacts the inner wall of the cavity to form a seal;

[0010] At least two oil ports, spaced apart and opened on the cylinder block, and the oil ports communicate with the cavity.

[0011] The present application is provided with a safety valve inside the cylinder block, and through this safety valve, the hydraulic cylinder can quickly relieve pressure in some cases, thereby ensuring the safety of the present application.

[0012] On the basis of the above technical solutions, the embodiment of the present application can also be improved as follows:

[0013] Furthermore, the safety valve is threadedly connected to the piston end of the piston rod. The beneficial effect of this step is that it facilitates the installation of the safety valve.

[0014] Furthermore, the safety valve is a cartridge type overflow valve. The beneficial effect of this step is that through the specific valve, it can ensure that the present application realizes the function of safe overflow.

[0015] Furthermore, the piston end of the piston rod divides the cavity into a rod chamber and a rodless chamber. The beneficial effect of this step is that through the change of pressure on both sides, the reciprocating movement of the piston rod can be realized.

[0016] Furthermore, two channels are opened inside the piston rod. One of the channels is respectively communicated with the rod chamber and the safety valve, and the remaining one channel is respectively communicated with the rodless chamber and the safety valve. The beneficial effect of this step is that through multiple channels, they are communicated with the safety valve in cooperation.

[0017] Furthermore, it further includes:

[0018] A first sealing ring, which is sleeved on the piston end of the piston rod, and the outer wall of the first sealing ring cooperates with the inner wall of the cylinder block to form a seal;

[0019] A second sealing ring, which is installed on the inner wall of the seal, and the second sealing ring contacts the outer wall of the piston rod to form a seal;

[0020] A third sealing ring, which is installed on the outer wall of the seal, and the third sealing ring contacts the inner wall of the cavity to form a seal. The beneficial effect of this step is to ensure the overall sealing performance.

[0021] Furthermore, the piston rod is an integrally formed part. The beneficial effect of this step is to ensure the stability of processing and at the same time facilitate installation.

[0022] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0023] 1. In the present application, a safety valve is provided inside the cylinder block of the hydraulic cylinder, so as to realize rapid overflow and pressure limit, and effectively avoid the defect of externally connecting a safety valve through a hydraulic pipeline.

[0024] 2. In the present application, the safety valve is built into the hydraulic cylinder, which can prevent the artificial random adjustment of the set pressure of the safety valve and ensure the safe use of the hydraulic chuck.

[0025] 3. In the present application, the external safety valve and its connected hydraulic pipeline are removed, which can reduce the space utilization and avoid accidents caused by pipeline leakage and bursting. Description of the Drawings

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Structural schematic diagram of a lifting hydraulic cylinder for a hydraulic slip with an internal safety valve according to a specific embodiment of the present invention;

[0028] 1 - cylinder block; 2 - piston rod; 3 - safety valve; 4 - seal; 5 - oil port; 6 - rod chamber; 7 - first sealing ring; 8 - second sealing ring; 9 - third sealing ring; 10 - rodless chamber;

[0029] 101 - opening; 102 - cavity;

[0030] 201 - channel. Specific embodiments

[0031] The following will describe in detail the embodiments of the technical solutions of the present invention in conjunction with the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0032] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0033] In this application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] To better understand the above technical solutions, the following will detail the above technical solutions in conjunction with the specification drawings and specific embodiments.

[0035] Embodiment:

[0036] As Figure 1As shown in the figure, the present application discloses a lifting hydraulic cylinder for a hydraulic slip with a built-in safety valve, which realizes rapid overflow pressure limitation through the built-in safety valve, effectively avoiding the defect of externally connecting a safety valve through a hydraulic pipeline (which is likely to cause the working oil chamber pressure of the lifting hydraulic cylinder to be higher than the set pressure of the safety valve). Moreover, the safety valve in the present application is a built-in safety valve, which can effectively prevent the safety valve from being manually adjusted, thus ensuring the safe use of the slip.

[0037] The specific structure of the present application is as follows:

[0038] Cylinder block 1, within which there is a cavity 102 with an opening 101 at one end. This cylinder block 1 is an existing cylinder block, and the internal cavity 102 facilitates the subsequent formation of a sealed cavity.

[0039] Piston rod 2, the piston end of which is located inside the cavity 102 and contacts and closes the inner wall of the cavity 102, so as to provide corresponding power subsequently.

[0040] Safety valve 3, installed at the piston end of the piston rod 2. In the present application, the piston end of the piston rod 2 is close to the inner bottom side at the right side of the cavity 102. This safety valve 3 is a built-in safety valve, which can avoid external interference and thus better realize the function of the safety valve 3.

[0041] Sealing member 4, installed on the piston rod 2, and the outer wall of the sealing member 4 contacts the inner wall of the cavity 102 to form a seal. This sealing member 4 makes the cavity 102 form a seal, thus realizing the function of the hydraulic cylinder in the present application.

[0042] At least two oil ports 5, spaced apart and opened on the cylinder block 1, and the oil ports 5 are communicated with the cavity 102. The present application is provided with two oil ports 5, which, in cooperation with the sealed cavity, can realize the movement of the piston rod 2.

[0043] Specifically, the safety valve 3 is threadedly connected to the piston rod 2, which can ensure the stability of the safety valve after installation and also facilitate its subsequent disassembly and assembly.

[0044] Specifically, the safety valve 3 is a cartridge-type overflow valve, and this safety valve 3 is used to realize the protection function.

[0045] Among them, the piston end of the piston rod 2 divides the cavity 102 into a rod chamber 6 and a non-rod chamber 10, and the rod chamber 6 and the non-rod chamber 10 are respectively communicated with the oil ports 5 one by one, which facilitates subsequent operation of the piston rod to make it move back and forth.

[0046] Specifically, two channels 201 are formed inside the piston rod 2. One of the channels 201 is respectively connected to the rod chamber 6 and the safety valve 3, and the remaining one of the channels 201 is respectively connected to the rodless chamber 10 and the safety valve 3. The safety valve is connected through multiple channels to achieve rapid overflow pressure limitation.

[0047] To ensure the sealing performance of the structure of the present application, the present application further includes:

[0048] A first sealing ring 7, which is sleeved on the piston end of the piston rod 2;

[0049] A second sealing ring 8, which is installed on the inner wall of the seal 4, and the second sealing ring 8 contacts the outer wall of the piston rod 2 to form a seal;

[0050] A third sealing ring 9, which is installed on the outer wall of the seal 4, and the third sealing ring 9 contacts the inner wall of the cavity 102 to form a seal. The first sealing ring 7, the second sealing ring 8 and the third sealing ring 9 in the present application cooperate with each other to achieve the sealing performance of the present application. At the same time, guiding rings and other components can also be added at corresponding positions in the present application to facilitate the stable operation of the entire device.

[0051] Specifically, the piston rod 2 is an integrally formed part, which is convenient for the present application to achieve the function of the hydraulic cylinder.

[0052] For further explanation of the present application:

[0053] Specifically, a safety valve is provided inside the lifting hydraulic cylinder of the hydraulic slip. The safety valve is a threaded cartridge type overflow valve; the piston and piston rod of the lifting hydraulic cylinder are of an integral structure. Threaded sockets are machined inside the piston end of the piston rod, and the safety valve is screwed into the inside of the piston rod through threads; channels are added inside the piston rod. Through this channel, it is connected to the high-pressure port P and the rodless chamber of the safety valve, and another channel is connected to the overflow port T and the rod chamber of the safety valve, so as to form a safety protection function.

[0054] During use, adjust and set the opening pressure of the safety valve according to the rated pressure of the hydraulic slip, and securely lock the pressure adjustment screw of the safety valve. Then install the safety valve inside the cylinder block, and finally install the present application on the clamp head lifting mechanism of the hydraulic slip; when the present application works, as the load increases, the pressure inside the rodless chamber of the present application rises. When the pressure value reaches the set pressure of the safety valve, the safety valve opens, the high-pressure port P communicates with the overflow port T, and the pressure oil in the rodless chamber flows directly into the rod chamber through the two channels, so that the pressure oil in the rodless chamber achieves rapid overflow pressure limitation, thereby ensuring that the working pressure of the lifting hydraulic cylinder does not exceed the rated pressure.

[0055] In the description of the present utility model, a large number of specific details are set forth. However, it will be understood that embodiments of the present utility model may be practiced without these specific details. In some instances, well-known methods, structures and technologies have not been shown in detail so as not to obscure the understanding of this description.

[0056] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without conflicting with each other, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0057] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model, and they should all be covered by the scope of the claims and the description of the present utility model.

Claims

1. A lifting hydraulic cylinder for a hydraulic slip with a built-in safety valve, characterized in that, Comprising: A cylinder block (1) having a cavity (102) with one end open (101) provided therein; A piston rod (2) with its piston end located inside the cavity (102) and in contact with the inner wall of the cavity (102) to form a seal; A safety valve (3) mounted on the piston end of the piston rod (2); A seal (4) mounted on the piston rod (2), and the outer wall of the seal (4) is in contact with the inner wall of the cavity (102) to form a seal; At least two oil ports (5) spacedly provided on the cylinder block (1), and the oil ports (5) communicate with the cavity (102).

2. The lifting hydraulic cylinder for the hydraulic slip, characterized in that The safety valve (3) is threadedly connected to the piston end of the piston rod (2).

3. The lifting hydraulic cylinder for the hydraulic slip, characterized in that, The safety valve (3) is a cartridge type overflow valve.

4. The lifting hydraulic cylinder for the hydraulic slip, characterized in that The piston end of the piston rod (2) divides the cavity (102) into a rod chamber (6) and a non-rod chamber (10).

5. The lifting hydraulic cylinder for a hydraulic slip, characterized in that Two channels (201) are provided inside the piston rod (2), one of the channels (201) communicates with the rod chamber (6) and the safety valve (3) respectively, and the remaining one of the channels (201) communicates with the non-rod chamber (10) and the safety valve (3) respectively.

6. The lifting hydraulic cylinder for the hydraulic slip, characterized in that It further comprises: A first sealing ring (7) sleeved on the piston end of the piston rod (2), and the outer wall of the first sealing ring (7) cooperates with the inner wall of the cylinder block (1) to form a seal; A second sealing ring (8) mounted on the inner wall of the seal (4), and the second sealing ring (8) is in contact with the outer wall of the piston rod (2) to form a seal; A third sealing ring (9) mounted on the outer wall of the seal (4), and the third sealing ring (9) is in contact with the inner wall of the cavity (102) to form a seal.

7. The lifting hydraulic cylinder for a hydraulic slip, characterized in that The piston rod (2) is an integrally formed part.

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