Fastening device for bolt torque in limited space

Abstract

The utility model relates to a space-limited bolt torque fastening device which comprises a bolt body and a lifting unit, the bolt body axially penetrates through a to-be-fastened piece and is in threaded connection with the to-be-fastened piece, the lifting unit comprises a lifting piece and a linear power mechanism, the lifting piece is connected with the bolt body, and the linear power mechanism is connected with the lifting piece. And the linear power mechanism applies axial tension to the bolt body through the lifting piece, so that the bolt body generates target torque. Axial force output by the linear power mechanism acts on the bolt body, target torque is generated, and threaded fastening connection of a to-be-fastened piece is completed. When the linear power mechanism outputs axial force, the movement direction of the linear power mechanism is linear, relative to rotation operation of a torque wrench, only a small operation space is needed, the problem of bolt torque fastening under the condition that the space is limited is solved, accurate axial force can be obtained by controlling a hydraulic oil pump and accurately controlling reading of a pressure gauge, and the operation is simple and convenient. The set bolt target torque is applied to the bolt body, and the fastening stability of the bolt is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of automobiles, in particular to a fastening device for bolt torque in a restricted space. Background Technique

[0002] Bolt connection is a commonly used connection method in mechanical engineering. Its basic principle is to firmly connect two connected parts by using the pre-tightening force and friction force of the bolt. Bolt connection usually includes the following main components: a bolt, a cylinder with an external thread; a nut, a component with an internal thread used to cooperate with the bolt; a washer (optional), located between the nut and the connected part, used to disperse the load and reduce friction; the connected parts, two or more parts to be connected (such as flanges and valves, etc.). When the bolt is tightened, the applied torque is transmitted through the thread, causing the nut to rotate, thereby applying a tensile force on the bolt, which is the pre-tightening force. The pre-tightening force is the core of the bolt connection, which ensures the stability of the connection. By applying the torque (torsion), the bolt is stretched axially to form a pre-tightening force. This tensile force makes the two connected parts closely contact each other, preventing relative displacement between them. In addition, the friction force in the bolt connection also plays an important role. There is friction force between the nut and the connected part or the bolt body. When the nut is tightened, the friction force helps to resist the relative movement of the external force on the connected part. This friction force is usually an important factor for the connected part to maintain stability and resist shear force in the working state. By combining the pre-tightening force and the friction force, the bolt connection can bear external loads, such as static loads and dynamic loads (vibration, impact, etc.), ensuring that the connected parts will not loosen. Sufficient pre-tightening force and friction force ensure the firmness of the connection, avoiding displacement and loosening between the connected parts during the working process. The principle of bolt connection is based on the combination of pre-tightening force and friction force. By applying torque, the bolt generates axial tensile force, thereby ensuring effective contact and firm connection between the connected parts.

[0003] Therefore, when designing a bolt connection, the following factors need to be considered: the magnitude of the pre-tightening force: considering the strength, thickness and use conditions of the material to ensure sufficient pre-tightening force to resist external loads; the control of torque: reasonably select and control the applied torque to avoid material damage or bolt breakage caused by over-tightening; using appropriate washers and lubricants: using washers can enhance the stability of the connection, and using lubricants can reduce friction and improve the fastening efficiency.

[0004] Currently, applying torque to a bolt is generally completed by a torque wrench, which requires a relatively high space and needs to ensure a certain rotation space for the force arm of the torque wrench. However, during the repair of valves, flanges, etc., according to the real-time construction position, if there are obstacles such as walls or pipes, it is impossible to use a torque wrench to tighten the bolts, which will cause the fastening nuts of some flanges not to be tightened, or the target torque to be applied to the bolts cannot be guaranteed.

[0005] Therefore, it is necessary to design a fastening device for bolt torque in a restricted space. Summary of the Invention

[0006] In view of the above partial drawbacks of the prior art, a fastening device for bolt torque in a restricted space provided by the present utility model solves the problem of bolt torque fastening in a restricted space. It only requires a small space and can fasten the bolt to the standard torque, i.e., the target torque, to ensure the assembly quality of the bolt.

[0007] To achieve the above object, the present utility model specifically includes the following technical solutions:

[0008] A fastening device for bolt torque in a restricted space includes:

[0009] A bolt body that axially penetrates the fastener to be fastened and is threadedly connected to the fastener to be fastened; and

[0010] A lifting unit that includes a lifting member and a linear power mechanism. The lifting member is connected to the bolt body, and the linear power mechanism applies an axial tensile force to the bolt body through the lifting member to generate a target torque on the bolt body.

[0011] As one embodiment of the present utility model, the linear power mechanism includes at least a pair of hydraulic jacks, a hydraulic oil pump, and a pressure gauge. The hydraulic oil pump is respectively connected to the oil inlets of a pair of hydraulic jacks through oil pipes, and a pressure gauge is provided on the oil pipes.

[0012] As one embodiment of the present utility model, the lifting member is a lifting nut. A boss is provided on the outer cylindrical surface at one end of the lifting nut. The lifting nut is threadedly connected to the bolt body, and the extending ends of a pair of hydraulic rods of a pair of hydraulic jacks abut against the boss of the lifting nut.

[0013] As one embodiment of the present utility model, a pair of hydraulic rods of a pair of hydraulic jacks are coaxial and symmetrically arranged along the radial direction of the lifting nut 21.

[0014] As one embodiment of the present utility model, the lifting nut is threadedly connected to the stud of the bolt body, and the threaded connection length is greater than the nominal diameter of the stud.

[0015] As one embodiment of the present utility model, the fastener to be fastened is a pair of connecting flanges.

[0016] As one embodiment of the present utility model, the bolt body includes a stud and a pair of fastening nuts. The stud axially penetrates a pair of connecting flanges, and a pair of fastening nuts are threadedly connected to the stud and respectively correspond to and fit against the mutually remote first side surface and second side surface of the pair of connecting flanges.

[0017] As one embodiment of the present utility model, a pair of hydraulic rods of a pair of hydraulic jacks are symmetrically arranged along the radial direction of a pair of connecting flanges on their first side, and the extending ends of the pair of hydraulic rods are away from the first side and abut against the convex platforms of the lifting nuts.

[0018] As one embodiment of the present utility model, gaskets are provided between a pair of fastening nuts and the first side and the second side respectively, and the gasket is one of a flat gasket, a spring gasket, a sealing gasket or a locking gasket.

[0019] As one embodiment of the present utility model, the oil outlet of the hydraulic oil pump is connected to the oil inlet of the pressure gauge through Oil Pipe Ⅰ, the oil outlet of the pressure gauge is divided into two paths, and the two paths are respectively connected to a pair of oil inlets of a pair of hydraulic jacks through Oil Pipe Ⅱ and Oil Pipe Ⅲ.

[0020] The beneficial technical effects of the present utility model at least include the following:

[0021] A fastening device for bolt torque in a limited space of the present utility model includes a bolt body and a lifting unit. The bolt body axially penetrates through a component to be fastened and is threadedly connected to the component to be fastened. The lifting unit includes a lifting member and a linear power mechanism. The lifting member is connected to the bolt body, and the linear power mechanism applies an axial pulling force to the bolt body through the lifting member, so that the bolt body generates a target torque. Through the axial force output by the linear power mechanism acting on the bolt body, a target torque is generated, so that the bolt body applies a pre-tightening force to the component to be fastened, and the threaded fastening connection is completed. When the linear power mechanism outputs the axial force, its movement direction is linear. Compared with the rotational operation of a torque wrench, only a smaller operation space is required to complete, solving the problem of bolt torque fastening in a space-limited situation. Moreover, the linear power mechanism includes a pair of hydraulic jacks. By controlling the hydraulic oil pump, the reading of the pressure gauge is accurately controlled to obtain an accurate axial force, so that a set bolt target torque is applied to the bolt body. Ensure the assembly quality of the bolt body and ensure the stability of the threaded connection. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of a fastening device for bolt torque in a limited space provided by an embodiment of the present utility model.

[0023] Figure 2 It is a cross-sectional view of a lifting nut provided by an embodiment of the utility model.

[0024] Element Symbol Description:

[0025] Bolt body 1, stud 11, a pair of fastening nuts 12, lifting unit 2, lifting nut 21, boss 211, linear power mechanism 22, a pair of hydraulic jacks 221, hydraulic oil pump 222, pressure gauge 223, oil pipe Ⅰ 224, through oil pipe Ⅱ 225, oil pipe Ⅲ 226, a pair of connecting flanges 3, first side 31, second side 32. Specific embodiments

[0026] The following specific examples illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0027] It should be noted that the illustrations provided in the following embodiments only schematically show the basic concept of the present utility model. Therefore, only the components related to the present utility model are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0028] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present utility model. However, it is obvious to those skilled in the art that the embodiments of the present utility model can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present utility model difficult to understand.

[0029] It should be noted that the principle of bolt connection is based on the combination of pre-tightening force and friction. By applying torque, axial tension is generated in the bolt, thereby ensuring effective contact and firm connection between the connected parts. In the embodiment, a pair of connecting flanges 3 are firmly connected together. To ensure the stability of flange connection, corresponding tightening markings, that is, setting the bolt target torque, will be set.

[0030] According to the method introduced in Appendix Z of the RCCM (Reliability-Centered Maintenance) specification, the detailed formulas and explanations are shown in Table 1 below. The axial tension of the bolt (the load Pv transmitted to the bolt) can be calculated inversely based on the bolt target torque (tightening torque Cs).

[0031] Table 1

[0032]

[0033] As can be seen from Table 1 above, the tightening torque C can be obtained from the formula S and the conversion relationship between the load Pv transmitted to the bolt and the transmitted force.

[0034] Please refer to Figures 1 to 2 , a tightening device for bolt torque in a confined space provided by the present utility model includes a bolt body 1 and a lifting unit 2. The bolt body 1 axially penetrates the fastener to be fastened and is threadedly connected to the fastener to be fastened; the lifting unit 2 includes a lifting member and a linear power mechanism 22. The lifting member is connected to the bolt body 1, and the linear power mechanism 22 applies an axial tensile force to the bolt body 1 through the lifting member, so that the bolt body 1 generates a target torque.

[0035] When the target torque of the bolt is a set value, according to Table 1, the value of the axial force that the linear power mechanism 22 needs to output can be calculated. The axial force output by the linear power mechanism 22 acts on the bolt body 1 to generate a target torque, and the threaded fastening connection of the fastener to be fastened is completed. When the linear power mechanism 22 outputs the axial force, its movement direction is linear. Compared with the rotational operation of a torque wrench, only a smaller operating space is required. The problem of bolt torque tightening in a space-limited situation is solved. Only a smaller space is required, and the bolt can be tightened to the standard torque, that is, the target torque, to ensure the bolt assembly quality.

[0036] As one embodiment of the present utility model, the linear power mechanism 22 includes at least a pair of hydraulic jacks 221, a hydraulic oil pump 222, and a pressure gauge 223. The oil outlet of the hydraulic oil pump 222 is connected to the oil inlet of the pressure gauge 223 through a pipeline Ⅰ224. The oil outlet of the pressure gauge 223 is divided into two paths, and the two paths are respectively connected to a pair of oil inlets of a pair of hydraulic jacks 221 through pipelines Ⅱ225 and Ⅲ226.

[0037] As one embodiment of the present utility model, the lifting member is a lifting nut 21. A boss 211 is provided on the outer cylindrical surface at one end of the lifting nut 21. The lifting nut 21 is threadedly connected to the bolt body 1. The extending ends of a pair of hydraulic rods of a pair of hydraulic jacks 221 abut against the boss 211 of the lifting nut 21. A pair of hydraulic rods of a pair of hydraulic jacks 221 are coaxially arranged and symmetrically arranged along the radial direction of the lifting nut 21. That is to say, a pair of hydraulic rods of a pair of hydraulic jacks 221 are coaxially and symmetrically arranged at both radial ends of the lifting nut 21. The lifting nut 21 is threadedly connected to the stud 11 of the bolt body 1, and the threaded connection length is greater than the nominal diameter of the stud 11.

[0038] As one embodiment of the present utility model, the fastener to be fastened is a pair of connecting flanges 3. The bolt body 1 includes a stud 11 and a pair of fastening nuts 12. The stud 11 axially penetrates through the pair of connecting flanges 3, and the pair of fastening nuts 12 are threadedly connected to the stud 11 and respectively fit against the mutually remote first side surface 31 and second side surface 32 of the pair of connecting flanges 3. A pair of hydraulic rods of a pair of hydraulic jacks 221 are symmetrically arranged on the first side surface 31 of the pair of connecting flanges 3 along the radial direction thereof. The extending ends of the pair of hydraulic rods are away from the first side surface 31 and abut against the boss 211 of the lifting nut 21.

[0039] As one embodiment of the present utility model, gaskets are provided between the pair of fastening nuts 12 and the first side surface 31 and the second side surface 32 respectively. The gasket is one of a flat gasket, a spring gasket, a sealing gasket or a locking gasket.

[0040] The fastening device of the present utility model specifically includes the following operation steps:

[0041] Step (1): First, obtain the set value of the bolt target torque C S and calculate the P V value according to the following formula.

[0042]

[0043] Wherein, f = the friction coefficient between threads, r = the radius of the bolt thread crest, f 1 = the friction coefficient between the nut and the gasket, R ma = the arithmetic mean of the nominal radius of the screw rod and the radius of the nut seat surface. F, r, f 1 and R ma are all known values.

[0044] Step (2): According to the formula Pv = P * S, wherein the hydraulic transmission area S of the pair of hydraulic jacks 221 is known, and Pv is obtained from step (1), directly calculate the pressure value P.

[0045] Step (3): Screw the lifting nut 21 onto the upper part of the stud 11 and ensure that the thread engagement length is greater than the nominal diameter of the stud 11 to prevent loosening.

[0046] Step (4) Then slowly operate the hydraulic oil pump 222 until the pressure gauge 223 reaches the pressure value P. At this time, manually tighten the pair of fastening nuts 12 and ensure that the pair of fastening nuts 12 respectively fit against the mutually remote first side surface 31 and second side surface 32 of the pair of connecting flanges 3. Thus, the fastening target is achieved.

[0047] In summary, when the bolt target torque C S is the set value, according to the formula: The load Pv of the bolt can be calculated, that is, the axial load that a pair of hydraulic jacks 221 need to apply to the lifting nut 21 is obtained. Then, according to the formula: Pv = P * S, only the hydraulic oil pump 222 needs to be adjusted so that the reading of the pressure gauge 223 is the pressure value P, and the bolt torque tightening of a pair of connecting flanges 3 can be completed. The axial force output by the linear power mechanism 22 acts on the bolt body 1 to generate the target torque, and the threaded fastening connection of the to-be-fastened part is completed. When the linear power mechanism 22 outputs the axial force, its movement direction is linear. Compared with the rotational operation of the torque wrench, only a smaller operation space is required. The problem of bolt torque tightening under limited space is solved, and by controlling the hydraulic oil pump 222, the reading of the pressure gauge 223 is accurately controlled, so that the set bolt target torque C is applied to the bolt body 1. S . Ensure the bolt assembly quality and the stability of the connection.

[0048] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0049] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A fastening device for bolt torque in a confined space, characterized in that: include: A bolt body (1), the bolt body (1) axially penetrates the fastener to be fastened and is threadedly connected to the fastener to be fastened; as well as A lifting unit (2), the lifting unit (2) comprising a lifting member and a linear power mechanism (22), the lifting member and the bolt body (1) are fixedly connected, the linear power mechanism (22) applies an axial pulling force to the bolt body (1) through the lifting member, so that the bolt body (1) generates a target torque.

2. The fastening device according to claim 1, characterized in that: The linear power mechanism (22) comprises at least one pair of hydraulic jacks (221), a hydraulic oil pump (222) and a pressure gauge (223); the hydraulic oil pump (222) is connected to the oil inlets of the pair of hydraulic jacks (221) through oil pipes, and the pressure gauge (223) is provided on the oil pipes.

3. The fastening device according to claim 2, characterized in that: The lifting member is a lifting nut (21), and a boss (211) is provided on the outer cylindrical surface of one end of the lifting nut (21). The lifting nut (21) is threadedly connected to the bolt body (1), and the protruding ends of a pair of hydraulic rods of the pair of hydraulic jacks (221) abut against the boss (211) of the lifting nut (21).

4. The fastening device according to claim 3, characterized in that: The pair of hydraulic rods of the pair of hydraulic jacks (221) are coaxially arranged and symmetrically disposed along the radial direction of the lifting nut (21).

5. The fastening device according to claim 3, characterized in that: The lifting nut (21) is threadedly connected to the stud (11) of the bolt body (1), and the threaded connection length is greater than the nominal diameter of the stud (11).

6. The fastening device according to claim 3, characterized in that: The fasteners to be fastened are a pair of connecting flanges (3).

7. The fastening device according to claim 6, characterized in that: The bolt body (1) comprises a stud (11) and a pair of fastening nuts (12); the stud (11) axially penetrates the pair of connecting flanges (3); the pair of fastening nuts (12) are threadedly connected to the stud (11) and respectively fit with a first side surface (31) and a second side surface (32) of the pair of connecting flanges (3) that are away from each other.

8. The fastening device according to claim 7, characterized in that The pair of hydraulic rods of the pair of hydraulic jacks (221) are symmetrically arranged on the first side surface (31) of the pair of connecting flanges (3) along the radial direction, and the protruding ends of the pair of hydraulic rods are away from the first side surface (31) and abut against the boss (211) of the lifting nut (21).

9. The fastening device according to claim 8, characterized in that Gaskets are provided between the pair of fastening nuts (12) and the first side surface (31) and the second side surface (32), and the gaskets are selected from the group consisting of flat gaskets, spring gaskets, sealing gaskets and locking gaskets.

10. The fastening device according to claim 2, characterized in that: The oil outlet of the hydraulic oil pump (222) is connected to the oil inlet of the pressure gauge (223) through an oil pipe I (224); the oil outlet of the pressure gauge (223) is divided into two paths, and the two paths are connected to a pair of oil inlets of the pair of hydraulic jacks (221) through oil pipe II (225) and oil pipe III (226) respectively.

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