Bolt hole cold extrusion device

Abstract

The invention discloses a bolt hole cold extrusion device, and belongs to the field of hole cold extrusion equipment. Comprising an electric cylinder, a first extrusion device and a second extrusion device, the first extrusion device comprises a working shaft, and the working shaft comprises a shaft section, a working section and a mounting section; the working section comprises a sleeve, and an extrusion ring is arranged on the periphery of the sleeve. The mounting section comprises a connecting shaft which is integrally formed and arranged at the end part of the shaft section; an inner threaded hole is formed in the other end of the shaft section; a threaded connector is arranged at the output end of the electric cylinder and is in threaded connection with the inner threaded hole. The device has the beneficial effects that an expansion structure is designed according to the thought that a second extrusion device converts rotary motion into radial motion, an arc-shaped groove hole in a grooved wheel is designed through rotation of the grooved wheel, and the groove is deflected by an angle in the radial direction, so that rotary sliding of a sliding block in the arc-shaped groove hole can be converted into linear motion in the radial direction; rotary motion is converted into linear motion; and a stable cold pressing acting force is further provided for the threaded hole.

Description

Technical Field

[0001] The invention relates to a bolt hole cold extrusion device, belonging to the field of cold extrusion equipment for holes. Background Art

[0002] Bolt holes play many very important roles in mechanical design. Bolt holes have the functions of fixing parts, facilitating disassembly, supporting, adjusting positions, preventing loosening, overload protection, reducing weight and facilitating installation. Bolt holes are not only used for basic connection functions, but also have other important auxiliary functions, including but not limited to reducing weight, simplifying installation, and monitoring the tightening force of bolts. In view of the important role of bolt holes, it is particularly important to avoid their failure and cracking. The reasons for the cracks in bolt holes are that the material is too brittle. Studies have shown that the bolt holes on the heat sink of air-cooled cylinder liners are too brittle because the materials used contain a large amount of supercooled graphite and free cementite; multiple disassembly causes the bolt holes to reach the fatigue limit, and improper sealing causes corrosion and wear on the bolt holes, which will cause cracks in the bolt holes, leading to connection failure.

[0003] At present, domestic and foreign scholars have conducted a lot of research on hole strengthening. Many scholars have adopted a variety of methods for hole strengthening, but cold extrusion has always been the main method for hole strengthening. Among them, the hole strengthening technology using slotted bushings is relatively mature. Its principle is to produce a certain range of compressive stress areas around the hole by extrusion, thereby forming a residual stress distribution that is conducive to improving strength. Under the action of external loads, the stress amplitude and average stress can be reduced, thereby improving the phenomenon of stress concentration around the hole, thereby increasing the fatigue life of the fatigue zone of the key part of the body structure.

[0004] Meanwhile, the prior art basically implements cold extrusion by inserting the cold pressing device into the threaded hole through radial force. The applicant believes that this will damage the inner wall of the threaded hole, so a new cold extrusion structure is provided. Summary of the invention

[0005] The object of the present invention is to provide a bolt hole cold extrusion device which can effectively solve the above-mentioned problems.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: It comprises an electric cylinder and a first extrusion device connected to the electric cylinder, wherein a second extrusion device is arranged at one end of the first extrusion device; the first extrusion device comprises a working shaft, wherein the working shaft comprises a shaft section and a working section and a mounting section arranged at one end of the shaft section; The working section comprises a sleeve arranged at the end of the shaft section, and an extrusion ring is arranged on the outer periphery of the sleeve; The mounting section includes a connecting shaft integrally formed and arranged at the end of the shaft section; The other end of the shaft segment is provided with an internal threaded hole; The output end of the electric cylinder is provided with a threaded connector, and the threaded connector is threadedly connected to the internal threaded hole.

[0007] Further: the second extrusion device includes a motor and a groove wheel arranged at the output end of the motor, the end face of the groove wheel is circumferentially evenly distributed with arc-shaped groove holes, a slider is arranged in the arc-shaped groove hole, and an expansion blade is arranged on the slider, and the overall shape of the expansion blade is arc-shaped.

[0008] Further: a connecting structure is arranged between the second extrusion device and the first extrusion device, the connecting structure includes an external thread arranged at the end of the connecting shaft and a flange connecting piece arranged in the second extrusion device, the flange connecting piece is formed by a combination of a front flange and a rear flange, one end of the front flange is arranged with an internal thread matching the external thread, and the front flange and the rear flange form an installation space, the motor is fixed in the installation space, a reducer is arranged at the output end of the motor, the reducer is also arranged in the installation space, the output end of the reducer is connected to a coupling, the coupling is connected to a grooved wheel shaft, and the grooved wheel shaft cooperates with the grooved wheel through a spline.

[0009] Furthermore: a sheave cover is also provided on the sheave, and limiting grooves are evenly distributed on the circumference of the end surface of the sheave cover, and the sliding block is slidably arranged in the limiting grooves.

[0010] Further: a sliding rod is arranged between the arc-shaped slot and the sliding block, the sliding rod is inserted into the arc-shaped slot, and the sliding block is fixedly connected to the upper half of the sliding rod.

[0011] Further: the second extrusion device also includes a protective shell, and a limiting ring is provided at one end of the protective shell.

[0012] Furthermore: a cross reinforcement rib is arranged on the inner side of the expansion blade, and a mounting block with a cross groove is arranged between the sliding block and the cross reinforcement rib for fixed connection.

[0013] The beneficial effects are: The first extrusion device and the second extrusion device of the device can work independently, and can work in coordination by connecting the first extrusion device and the second extrusion device together through a connecting structure; The first extrusion device, with the help of a unique working section design, can not only be smoothly inserted into the threaded hole to be completed, but also provide a stable punching force to the threaded hole; The second extrusion device designs the expansion structure based on the idea of ​​converting rotational motion into radial movement. By rotating the groove wheel, the arc-shaped groove hole on the groove wheel is designed, and the groove is deflected at an angle along the radial direction so that the rotational sliding of the slider in the arc-shaped groove hole can be converted into linear motion along the radial direction, thereby realizing the conversion of rotational motion into linear motion; further stabilizing the cold pressing force on the threaded hole to be completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and the accompanying drawings.

[0015] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 is a cross-sectional view of a first extrusion device of the present invention; Figure 4 is a cross-sectional view of a second extrusion device of the present invention; Figure 5 It is the parts diagram of the motor and reducer of the present invention; Figure 6 It is the parts diagram of the coupling and the grooved wheel shaft of the present invention; Figure 7 It is a part diagram of the sheave cover of the present invention; Figure 8 It is the parts diagram of the groove wheel and expansion blade of the present invention; Fig. 9 This is a working state diagram of the first extrusion device of the present invention; Fig.10 This is a working state diagram of the second extrusion device of the present invention; Fig.11 This is a working state diagram of the first extrusion device combined with the second extrusion device of the present invention.

[0016] Description of reference numerals: 1. First extrusion device; 2. Second extrusion device; 21. Motor; 22. Groove wheel; 23. Arc-shaped slot hole; 24. Slider; 25. Expansion blade; 26. Reducer; 27. Coupling; 28. Groove wheel shaft; 29. ​​Sliding rod; 3. Working shaft; 31. Shaft section; 32. Working section; 321. Sleeve; 322. Extrusion ring; 323. Inclined surface; 33. Mounting section; 34. Internal threaded hole; 4. Connecting structure; 41. External thread; 42. Flange connector; 421. Front flange; 422. Rear flange; 5. Protective shell; 6. Limiting ring; 7. Cross reinforcing rib; 8. Mounting block; 10. Groove wheel cover; 11. Limiting groove. DETAILED DESCRIPTION

[0017] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0018] It should be noted that, in the description of the present invention, unless otherwise specified, “plurality” means two or more than two; the orientations or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “inside”, “outside”, “front end”, “rear end”, “head” and “tail” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0019] Furthermore, the terms “first,” “second,” “third,” etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0020] Meanwhile, in the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" 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.

[0021] See also Figure 1-11 This is an embodiment of a bolt hole cold extrusion device of the present invention. like Figure 1 , Figure 2 ; It includes an electric cylinder and a first extrusion device 1 connected to the electric cylinder; the first extrusion device 1 includes a working shaft 3, the working shaft 3 includes a shaft section 31 and a working section 32 and a mounting section 33 arranged at one end of the shaft section 31; the other end of the shaft section 31 is provided with an internal threaded hole 34; the mounting section 33 includes a connecting shaft integrally formed and arranged at the end of the shaft section 31; During assembly, the electric cylinder needs to be used as a reference to start installation, and the working shaft 3 is connected to the push rod of the electric cylinder through threads; the output end of the electric cylinder is provided with a threaded connector, which is threadedly connected to the internal threaded hole 34 provided on the shaft section 31; When the first extrusion device 1 is used, the electric cylinder is driven to push the first extrusion device 1, and the working shaft 3 is pushed toward the threaded hole to be processed; when the working section 32 is in contact, it works; See also Fig. 9The working section 32 includes a sleeve 321 arranged at the end of the shaft section 31, an extrusion ring 322 is arranged on the outer periphery of the sleeve 321, and an inclined surface 323 is arranged on the end face of the extrusion ring 322. The inclined surface 323 is pressed on the inner wall of the threaded hole at this time. Since the outer diameter of the entire extrusion ring 322 is slightly larger than the inner diameter of the threaded hole, the electric cylinder needs to apply a very strong thrust to push the extrusion ring 322 into the threaded hole. At this time, due to the setting of the sleeve 321, the entire sleeve 321 will be slightly deformed; the internal stress of the sleeve 321 provides a force for the threaded hole to complete the cold extrusion of the threaded hole.

[0022] like Figure 3 , for the second extrusion device 2: Then, the front and rear flanges are connected to the working shaft 3 through threads, the internal motor and reducer are connected to the groove wheel 22 shaft through a coupling, the groove wheel 22 and the groove wheel 22 shaft are connected through interference fit, and the groove wheel 22 is fixed by a ring groove nut, and then the groove wheel 22 is connected to the slider 24 in the groove wheel 22 cover by a connecting shaft, and then the expansion blades are installed, and finally the protective shell 5 is fixed to the front and rear flanges and the groove wheel 22 cover; A second extrusion device 2 is provided at one end of the first extrusion device 1; the second extrusion device 2 is also a structure for cold pressing the threaded hole to be processed; The second extrusion device 2 includes a motor 21 and a groove wheel 22 arranged at the output end of the motor 21. The end surface of the groove wheel 22 is circumferentially evenly distributed with arc-shaped slot holes 23. A slider 24 is arranged in the arc-shaped slot hole 23. The slider 24 is provided with an expansion blade 25. The overall shape of the expansion blade 25 is arc-shaped.

[0023] See also Figure 4-8 , Fig.10 When the second extrusion device 2 is in use, the motor 21 works to drive the groove wheel 22 to rotate. At this time, the position of the arc-shaped slot hole 23 on the groove wheel 22 changes, so that the slider 24 slides under the influence of the arc-shaped slot hole 23, and then the slider 24 drives the expansion blade 25 to move, and the expansion blade 25 presses on the inner wall of the threaded hole to complete the cold extrusion work of the threaded hole.

[0024] The second extrusion device 2 is designed with the idea of ​​converting rotational motion into radial movement to design the expansion structure. By rotating the groove wheel 22, the arc-shaped slot hole 23 on the groove wheel 22 is designed, and the slot is deflected at an angle along the radial direction so that the rotational sliding of the slider 24 in the arc-shaped slot hole 23 can be converted into a linear motion along the radial direction, thereby realizing the conversion of rotational motion into linear motion.

[0025] This device is used to strengthen bolt holes with a diameter of 80mm-100mm, and the diameter when expanded to the maximum is limited according to this size. Therefore, two extreme positions are determined based on the minimum of 80mm and the maximum of 100mm. At the same time, after modifying some data during modeling, the maximum diameter of the expansion device is finally determined to be 98mm, and the minimum diameter is designed to be 86mm based on the small outer diameter of the working shaft, which meets the design requirements of the mechanism.

[0026] See also Figure 8 A cross reinforcement rib 7 is arranged inside the expansion blade 25, and a mounting block 8 with a cross groove is arranged between the slider 24 and the cross reinforcement rib 7 for fixed connection.

[0027] According to the working shaft's small outer diameter of 86mm, the expansion blade's outer diameter is 86mm and its inner diameter is 80mm. The thickness of the blade is 3 mm. Since the blade is designed to be relatively thin, in order to effectively improve the overall strength and rigidity of the blade, a cross reinforcement rib 7 is added inside the expansion blade 25, which can effectively improve the seismic resistance of the structure, increase the ductility and energy absorption capacity of the structure, thereby reducing the deformation and damage of the structure. The cross reinforcement rib 7 can effectively control the expansion of cracks in the structure.

[0028] When subjected to external loads or stress concentration caused by structural deformation, the cross reinforcement ribs 7 can limit the expansion of cracks and maintain the integrity and stability of the structure; the cross reinforcement ribs 7 can improve the durability of the structure and extend the service life of the structure.

[0029] The mounting block 8 with a cross groove can reduce stress concentration and fatigue damage of the structure, reduce the maintenance cost of the structure, and improve the long-term stability of the structure. The cross reinforcement rib 7 can improve the deformation performance of the structure and reduce the deformation of the structure under load. A slope is designed on one side of the expansion blade 25 for transition. In addition, in order to allow the blade to expand, the blade is taken as 1 / 6 of a circular ring, the slope angle on both sides of the blade is 60°, and the height of the reinforcement rib on the blade is 4.35mm.

[0030] Since the expansion blade 25 plays the role of squeezing the hole wall, the material of the bolt hole is aluminum alloy, and the stress on the bolt hole wall is greater than its yield strength, it is necessary to select a metal with a yield strength greater than that of the aluminum alloy. Selecting 45 steel and performing a modulation process can meet the requirements.

[0031] In the device, a sliding rod 29 is arranged between the arc-shaped slot hole 23 and the sliding block 24 . The sliding rod 29 is inserted into the arc-shaped slot hole 23 , and the sliding block 24 is fixedly connected to the upper half of the sliding rod 29 .

[0032] See also Figure 8 , the groove wheel 22 in the present application document needs to open 6 arc-shaped slot holes 23 to install the sliding rod 29, so that the axial rotational motion is converted into radial linear motion through the rotation of the groove wheel 22. Therefore, in order to make the radial displacement of the sliding rod 29 in the groove reach 6mm, so that the minimum and maximum diameters of the expansion device are 86mm and 98mm respectively, the shape and position distribution of the groove on the groove wheel 22 are designed according to the size, and the 6 arc-shaped slot holes 23 are evenly distributed with the center of the groove wheel 22 as the axis; Since the sheave 22 needs to rotate, in order to minimize its mass to reduce its moment of inertia, a smaller diameter is selected as much as possible, and the outer diameter of the sheave 22 is finally designed to be 50 mm; the inner diameter of the sheave 22 should be selected as large as possible, and the inner diameter of the sheave 22 is finally designed to be 15 mm.

[0033] Since the groove wheel 22 needs to rotate, torque needs to be transmitted. First, the design is to mill a keyway on the inner diameter of the groove wheel 22 and connect it with an ordinary flat key. However, the contact area between the flat key and the hole slot is limited. When subjected to external loads, stress concentration may occur on the surface of the flat key and the hole slot, increasing the stress and possible fatigue damage of the material. In addition, the locking of the flat key connection depends on the tight fit between the key and the hole slot. If the fit is poor or looseness occurs, it will lead to unreliability and failure risk of the connection. High-precision processing and installation processes are required in the manufacture and installation of flat key connections, especially for large or complex-shaped flat keys, the processing and installation process may be more difficult and time-consuming. Ordinary flat key connections require a certain amount of space to accommodate the flat key itself and the hole slot, which may increase the gap between the connecting parts, thereby affecting the compactness and performance of the overall structure. Ordinary flat key connections may cause vibration and noise problems due to poor locking or loosening, especially when running at high speeds or subjected to impact loads.

[0034] In order to avoid this situation, the fixed connection part of the groove wheel 22 is appropriately improved. The keyway required for the flat key is removed, and three protrusions are directly fixed on the groove wheel 22. The keyway on the groove wheel 22 shaft that cooperates with it achieves interference fit with these three protrusions. The interference fit can prevent it from circumferential movement during the transmission process, and the interference fit can also be used to transmit torque. In addition, considering that the interference fit connection requires a wrench for installation and disassembly, but the connection space between the groove wheel 22 and the groove wheel 22 shaft is large, there is no need to reserve a hole for the wrench. The groove depth of the groove wheel 22 is designed to be 5mm. Since the bottom of the groove wheel 22 is not subjected to much force, the size of the bottom does not need to be designed too large, so the overall thickness of the groove wheel 22 is 7.5mm.

[0035] The device requires the sliding rod 29 to slide in the arc-shaped slot hole 23 of the groove wheel 22. Therefore, the groove wheel 22 alone cannot fix it in the sliding plane, and a groove wheel cover 10 needs to be designed to limit the movement of the slider 24. When designing the groove wheel cover 10, its outer diameter is determined according to the inner diameter of the expansion blade 25 minus the height of the cross reinforcement rib 7. The radius of the inner diameter of the expansion blade 25 that has been designed is 40mm, and the height of the cross reinforcement rib 7 of the expansion blade 25 is 4.35mm. Therefore, the diameter of the designed groove wheel cover 10 is 70mm, and no interference will occur when the expansion blade 25 is closed. In order to realize the movement of the expansion device, 6 limiting grooves 11 need to be designed on the groove wheel cover 10, and the groove wheel cover 10 needs to be fixed, so that the movement in the limiting grooves 11 on the groove wheel cover 10 transmitted through the rotational movement of the groove wheel 22 becomes a linear motion, so evenly distributed threaded holes are set between the limiting grooves 11 of the groove wheel cover 10 for fixed connection of the groove wheel cover 10. The sheave cover 10 is made of 45-gauge steel.

[0036] The thickness of the sliding rod 29 in the present application document is determined according to the depth of the arc-shaped slot hole 23 of the groove wheel 22. The arc-shaped slot hole 23 is designed to be 5mm deep, so the thickness of the sliding rod 29 is also 5mm. The thickness of the slider 24 is 10mm, and its material is 45# steel and modulated; the difference from the sliding rod 29 in the groove wheel 22 is that the sliding rod 29 in the groove wheel 22 is that the two sides need to be designed to be arc-shaped because it is in circular motion, while the slider 24 in the groove wheel cover 10 is in linear motion in the fixed groove wheel cover 10, so the two sides are flat, and its length is based on the expansion blade 25 so that the bottom does not interfere when it is closed, and a sufficient distance is left between the head and the cross reinforcement rib 7 of the expansion blade 25 to design the mounting block 8 with a cross groove.

[0037] A connecting structure 4 is arranged between the second extrusion device 2 and the first extrusion device 1, and the connecting structure 4 includes an external thread 41 arranged at the end of the connecting shaft and a flange connecting member 42 arranged in the second extrusion device 2. The flange connecting member 42 is formed by a front flange 421 and a rear flange 422. An internal thread matching the external thread 41 is arranged at one end of the front flange 421, and the front flange 421 and the rear flange 422 form an installation space. The motor 21 is fixed in the installation space. A reducer 26 is arranged at the output end of the motor 21, and the reducer 26 is also arranged in the installation space.

[0038] Since the device is used to achieve cold extrusion strengthening of bolt holes with thicker and thinner hole walls, it is not enough to simply design a drawing working shaft 3. Considering that the electric cylinder cannot achieve both drawing and expansion movements, it is necessary to connect a motor 21 and a reducer 26 to provide a larger torque, and convert the torque into radial pressure through a specific device. Therefore, it is necessary to design a space at the other end of the working shaft 3 connected to the electric cylinder to install the motor 21. After selecting the motor 21 and the reducer 26, a front flange 421 of a section of the working shaft 3 is designed, and the installation space between the front flange 421 and the rear flange 422 is used to fix the motor 21 and the reducer 26.

[0039] The size of the space inside the front flange 421 and the rear flange 422 is determined according to the size of the fixing flange of the motor 21 , so that the space inside the front flange 421 allows the motor 21 to have an interference fit after being installed.

[0040] After designing the front flange 421, the motor 21 and the reducer 26 need to be fixed in the hollow part in the middle of the front flange. Therefore, a rear flange 422 needs to be designed to cooperate with the front flange 421, and the flange on the reducer 26 needs to be fixed on the rear flange 422 to prevent the vibration generated by the motor 21 and the reducer 26 during operation from loosening the fixed parts. Therefore, after measuring the length of the motor 21 and the reducer 26 after cooperation, the size of the rear flange 422 is determined, and the threaded holes on the rear flange 422 are designed according to the threaded holes on the fixed flange on the reducer 26; the length of the motor 21 and the reducer 26 after cooperation is 45.07mm, and the length of the hollow part inside the front flange 421 for installing the motor 21 is 12mm, so the length of the rear flange 422 is 33.07mm.

[0041] The output end of the reducer 26 is connected with a coupling 27 , and the coupling 27 is connected with a sheave shaft 28 , and the sheave shaft 28 cooperates with the sheave 22 via a flat key.

[0042] The coupling 27 in this device is selected according to the diameter of the output shaft of the reducer 26. Since the diameter of the output shaft of the selected reducer 26 is 6.25 mm, the inner diameter of the coupling 27 is also selected to be 6.25 mm, and finally the ML2 coupling is selected.

[0043] For the sheave shaft 28, the sheave shaft 28 is interference fit with the protrusion of the sheave 22 to prevent the sheave 22 from vibrating on the sheave shaft 28. The torque can also be transmitted through the interference fit. Therefore, the diameter of the shaft section that matches the sheave 22 is 15 mm, and the diameter of the shaft shoulder that axially fixes the sheave 22 is 20 mm to limit the axial displacement of the sheave 22. The other side of the sheave 22 is threaded with an external thread, and the sheave is axially fixed by a ring groove nut through threaded connection. The material of the ring groove nut is 45 steel and is quenched and tempered.

[0044] The second extrusion device 2 further comprises a protective shell 5 , and a limiting ring 6 is disposed at one end of the protective shell 5 .

[0045] The design of the protective shell 5 in the present device requires that the bolt hole cold extrusion strengthening device fix the groove wheel cover 10 to realize the expansion extrusion function, so it is necessary to design a connecting device to connect the assembly of the stationary front flange 421 and the rear flange 422 to the groove wheel cover 10, and at the same time, the motor 21, the reducer 26, the coupling 27, the groove wheel shaft 28, the groove wheel 22 and other parts can be sealed; the protective shell 5 can effectively protect the internal components or elements of the system from the influence of the external environment, such as dust, moisture, corrosive substances, etc., which helps to extend the service life and reliability of the mechanical equipment; sealing the internal parts can improve the safety of the system; the adaptability of the mechanical equipment in harsh environments can be improved, for example, in high temperature, low temperature, high humidity or corrosive environment, the sealing mechanism can effectively protect the internal components and ensure the normal operation of the equipment.

[0046] Therefore, after assembling the internal parts, the size of the protective shell 5 is determined. Through measurement, it can be found that the size of the protective shell 5 is 99.15mm, so the total length is determined when designing the protective shell 5; then the thickness of the flanges on both sides of the protective shell 5 connected to the rear flange and the groove wheel cover are determined, and the threaded holes matching them are determined, and the flange thicknesses are determined to be 3mm and 6.51mm respectively; finally, the protective shell 5 is prevented from interfering with the inclined part of the expansion blade 25. Therefore, after adjusting the data, the size of the protective shell 5 is finally determined, the material is selected as 45 steel, and modulation treatment is performed.

[0047] See also Fig.11 When the first extrusion device and the second extrusion device are used in combination, the electric cylinder is first controlled to push the second extrusion device into the threaded hole without thread processing, and then the second extrusion device is started so that the expansion blade 25 is pressed into the threaded hole to perform the first stage of cold extrusion; After the first stage of cold extrusion is completed, the expansion blade 25 is retracted and the electric cylinder is continued to be controlled to push. At this time, the sleeve 321 of the first extrusion device will be pressed into the threaded hole, and the extrusion ring 322 will be pressed against the inner wall of the threaded hole; then the second extrusion device is started to press the expansion blade 25 against the inner wall of the threaded hole; in this way, the entire inner wall of the threaded hole can be cold extruded.

[0048] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A bolt hole cold extrusion device, characterized in that: The invention comprises an electric cylinder and a first extrusion device (1) connected to the electric cylinder, wherein a second extrusion device (2) is arranged at one end of the first extrusion device (1); the first extrusion device (1) comprises a working shaft (3), wherein the working shaft (3) comprises a shaft section (31), a working section (32) and a mounting section (33) arranged at one end of the shaft section (31); the working section (32) comprises a sleeve (321) arranged at the end of the shaft section (31), and an extrusion ring (322) is arranged on the outer periphery of the sleeve (321); the mounting section (33) comprises a connecting shaft integrally formed and arranged at the end of the shaft section (31); the other end of the shaft section (31) is provided with an internal threaded hole (34); a threaded connector is arranged at the output end of the electric cylinder, and the threaded connector is threadedly connected to the internal threaded hole (34).

2. The bolt hole cold extrusion device according to claim 1, characterized in that: The second extrusion device (2) comprises a motor (21) and a groove wheel (22) arranged at the output end of the motor (21); arc-shaped groove holes (23) are evenly distributed on the circumference of the end surface of the groove wheel (22); a slider (24) is arranged in the arc-shaped groove hole (23); an expansion blade (25) is arranged on the slider (24); and the overall shape of the expansion blade (25) is an arc.

3. The bolt hole cold extrusion device according to claim 2, characterized in that: A connection structure (4) is provided between the second extrusion device (2) and the first extrusion device (1), the connection structure (4) comprising an external thread (41) provided at the end of the connection shaft and a flange connection member (42) provided in the second extrusion device (2), the flange connection member (42) being formed by a combination of a front flange (421) and a rear flange (422), one end of the front flange (421) being provided with an internal thread matching the external thread (41), and the front flange (421) and the rear flange (422) forming an installation space, the motor (21) being fixed in the installation space, a reducer (26) being provided at the output end of the motor (21), the reducer (26) being also provided in the installation space, the output end of the reducer (26) being connected to a coupling (27), the coupling (27) being connected to a grooved wheel shaft (28), the grooved wheel shaft (28) being matched with the grooved wheel (22) via a spline.

4. The bolt hole cold extrusion device according to claim 3, characterized in that: A sliding rod (29) is provided between the arc-shaped slot hole (23) and the sliding block (24); the sliding rod (29) is inserted into the arc-shaped slot hole (23); and the sliding block (24) is fixedly connected to the upper part of the sliding rod (29).

5. The bolt hole cold extrusion device according to claim 4, characterized in that: A sheave cover (10) is also provided on the sheave (22), and limiting grooves (11) are evenly distributed on the circumference of the end surface of the sheave cover (10), and the sliding block (24) is slidably disposed in the limiting grooves (11).

6. The bolt hole cold extrusion device according to claim 5, characterized in that: The second extrusion device (2) further comprises a protective shell (5), and a limiting ring (6) is provided at one end of the protective shell (5).

7. The bolt hole cold extrusion device according to claim 6, characterized in that: A cross reinforcement rib (7) is provided inside the expansion blade (25), and a mounting block (8) with a cross groove is provided between the slider (24) and the cross reinforcement rib (7) for fixed connection.

Images