Automatic centering and clamping device for processing external thread of sucker rod head

Abstract

The application discloses an automatic centering and clamping device for processing of an outer thread of a sucker rod head, which comprises a base, a hydraulic chuck mechanism, an automatic clamping mechanism and at least two rotating support mechanisms being sequentially installed above the base; the automatic clamping mechanism comprises a sliding table, two support arms being fixedly installed on the sliding table and arranged side by side, and upper and lower rotating shafts being rotatably connected to the top ends of the two support arms; gears are fixedly installed on the upper and lower rotating shafts, the two gears are in mesh with each other, the top of the upper rotating shaft is vertically fixedly connected with an upper swing arm, and the bottom of the lower rotating shaft is vertically fixedly connected with a lower swing arm; a press roller is rotatably installed at the top end of the upper swing arm, and two rollers A arranged side by side are installed on the bottom end of the lower swing arm. The application can effectively solve the technical problems of machining vibration caused by uneven distribution of clamping force, low efficiency of type changing caused by insufficient specification adaptability, and flexing and jumping of slender rods caused by lack of auxiliary support rigidity.

Description

Technical Field

[0001] This invention relates to an automatic centering and clamping device for machining the external thread of a sucker rod head, belonging to the field of sucker rod machining technology. Background Technology

[0002] A sucker rod is a slender rod used in oil wells. A single sucker rod is connected by its external threaded tip, which is then screwed onto a coupling with internal threads. In this way, multiple sucker rods are connected to form a sucker rod string that can extend for thousands of meters, transmitting power from the surface to the underground to drive the oil pump and lift crude oil to the surface.

[0003] When machining the external threads of a sucker rod head, a clamping device is usually used for auxiliary fixation. However, traditional clamping devices generally have the following technical problems during use: 1. Uneven clamping force distribution easily leads to vibration. Existing devices mostly use unidirectional clamping methods with top or side pressure, resulting in uneven distribution of clamping force along the circumference of the rod, causing uneven load on the rod during processing. This uneven force further causes the rod to generate high-frequency vibration under radial and tangential impact loads, which in severe cases leads to deterioration of thread surface quality, decrease in tooth profile accuracy, and out-of-tolerance coaxiality, ultimately resulting in a high scrap rate.

[0004] 2. Poor specification adaptability and low changeover efficiency. Sucker rods come in various diameters and lengths, while the clamping point positions of existing clamping devices are relatively fixed. When dealing with sucker rods of different diameters and lengths, manual adjustment of the fixture position or replacement of tooling is required, resulting in long changeover times, low production efficiency, and difficulty in ensuring consistent positioning accuracy after each adjustment.

[0005] 3. Insufficient rigidity of auxiliary support, long rods are prone to bending and running. Slender rods are prone to bending deformation under their own weight and cutting forces. However, the existing device has a fixed height for the auxiliary support at the rod tail, which cannot provide coaxial support for sucker rods of different diameters. This leads to increased radial runout of the rod body during rotation, further affecting machining stability.

[0006] In summary, existing technologies are insufficient to meet actual processing needs, and a more comprehensive solution is urgently needed. Summary of the Invention

[0007] To address the shortcomings of the prior art, this invention provides an automatic centering and clamping device for machining the external thread of a sucker rod head. This device effectively solves the technical problems in the prior art, such as machining vibration caused by uneven clamping force distribution, low changeover efficiency due to insufficient specification adaptability, and bending and jumping of slender rods caused by insufficient rigidity of auxiliary support.

[0008] To solve the above technical problems, the present invention adopts the following technical solution: An automatic centering and clamping device for machining the external thread of a sucker rod head includes a base. A hydraulic chuck mechanism, an automatic clamping mechanism, and at least two rotating support mechanisms are sequentially mounted on the base. The automatic clamping mechanism includes a slide table that can slide in the area between the hydraulic chuck mechanism and the rotating support mechanisms. Two support arms are fixedly mounted side-by-side on the slide table, and an upper rotating shaft and a lower rotating shaft are rotatably connected to the tops of the two support arms. Gears are fixedly mounted on both the upper and lower rotating shafts, and the two gears mesh with each other. An upper swing arm is vertically fixed to the top of the upper rotating shaft, and a lower swing arm is vertically fixed to the bottom of the lower rotating shaft. A pressure roller is rotatably mounted on the top and bottom of the upper swing arm, and two rollers A are mounted side-by-side on the bottom of the lower swing arm. The pressure roller and the two rollers A together form a centering and clamping structure for the sucker rod.

[0009] Furthermore, the bottom end of the lower swing arm is a U-shaped bracket structure, with roller A rotatably mounted on the rotating shaft. Both ends of the rotating shaft are provided with mounting surfaces, and the U-shaped bracket structure has openings that are compatible with the mounting surfaces at both ends of the rotating shaft.

[0010] Furthermore, the end of the upper swing arm away from the pressure roller is hinged to the head of the cylinder, and the tail of the cylinder is hinged to the hinge shaft; the two ends of the hinge shaft are respectively installed on the ear seats correspondingly provided on the sides of the two support arms.

[0011] Furthermore, a compressed air station is fixedly installed on the slide table. The compressed air station moves with the slide table and is located on the side of the support arm. The compressed air station is connected to the cylinder through a pipeline.

[0012] Furthermore, the bottom of the slide table is slidably connected to the base via a slider and a linear slide rail. The slider is fixedly installed at the bottom of the slide table, and the linear slide rail is fixedly installed on the upper surface of the base.

[0013] Furthermore, a lead screw nut is fixedly installed at the middle position of the bottom of the slide table, and a lead screw with threaded engagement is installed inside the lead screw nut; the lead screw is arranged along the axial direction of the base, and its two ends are rotatably supported on the base through bearing seats, and one end of the lead screw is connected to a drive motor.

[0014] Furthermore, the rotating support mechanism includes a V-shaped lifting seat, on which two rollers B are mounted side by side.

[0015] Furthermore, roller B is rotatably mounted on a rotating shaft, with mounting surfaces at both ends of the shaft, and the lifting seat has openings that match the mounting surfaces at both ends of the shaft.

[0016] Furthermore, the lifting seat is fixedly installed on the lifting platform, which is located directly above the support box, and the support box is fixedly installed on the base.

[0017] Furthermore, a worm gear screw jack is installed between the lifting platform and the support box. At least two vertically arranged sliding rods are fixedly installed at the bottom of the lifting platform, and a linear bearing is provided at the connection between the sliding rod and the top wall of the support box, with the sliding rod and the linear bearing slidingly engaged.

[0018] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages: The high-precision centering and clamping effectively suppresses machining vibration. This invention utilizes a gear-meshing, synchronously rotating structure between the upper and lower swing arms to create a triangular centering clamping configuration between the pressure roller and the two rollers A, achieving three-way synchronous and uniform clamping of the sucker rod. The clamping force is evenly distributed along the circumference of the rod, eliminating the force imbalance defects of traditional unidirectional clamping methods. Simultaneously, the meshing transmission of the two gears ensures strictly symmetrical movement of the upper and lower swing arms, resulting in strong consistency in centering accuracy and eliminating the need for manual adjustment. Furthermore, both the pressure roller and rollers A are rotatably mounted, passively rotating with the sucker rod in the clamping state, providing only radial clamping force without generating circumferential frictional resistance. This effectively suppresses high-frequency vibration during the cutting process, significantly improving thread surface finish, tooth profile accuracy, and coaxiality, and drastically reducing the scrap rate.

[0019] The axial position is adjustable to accommodate different rod lengths. This invention uses a lead screw and lead screw nut to drive the slide table to move precisely back and forth along a linear guide rail, allowing the automatic clamping mechanism to slide freely between the hydraulic chuck mechanism and the rotating support mechanism. The clamping point position can be precisely adjusted numerically according to the length of the sucker rod, ensuring that the clamping point is always located at the optimal support span position, thus guaranteeing the processing stability of sucker rods of different lengths from the outset.

[0020] The V-shaped support height is adjustable to accommodate different rod diameters. In this invention, the rotating support mechanism employs a V-shaped lifting structure composed of a V-shaped lifting seat and two parallel rollers B, forming a two-point contact support with the sucker rod tail. This V-shaped structure has self-centering characteristics, automatically adapting to rods of different diameters while providing stable radial constraint on the rod body. The lifting platform is smoothly raised and lowered by a worm gear screw jack, allowing for flexible adjustment of the support height of rollers B. This ensures reliable support for sucker rods of different diameters, and the worm gear screw jack has a self-locking function to guarantee the continuous stability of the support rigidity.

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the main structural view of the automatic clamping mechanism; Figure 3 This is a side view of the automatic clamping mechanism. Figure 4 This is a schematic diagram showing the connection between roller A and the lower control arm; Figure 5 This is a schematic diagram of the rotating support mechanism.

[0023] In the diagram, 1-sucking rod; 2-base; 3-automatic clamping mechanism; 31-slide table; 32-slider; 33-linear slide rail; 34-screw nut; 35-screw; 36-support arm; 37-compressed air station; 38-upper shaft; 39-lower shaft; 310-gear; 311-upper swing arm; 312-lower swing arm; 313-pressure roller; 314-roller A; 315-cylinder; 316-ear seat; 317-hinge shaft; 4-rotation support mechanism; 41-lifting seat; 42-roller B; 43-lifting platform; 44-slide rod; 45-support box; 46-linear bearing; 47-worm gear screw jack; 5-hydraulic chuck mechanism. Detailed Implementation

[0024] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] like Figures 1-5 As shown in the figure, the present invention provides an automatic centering and clamping device for machining the external thread of the sucker rod head, including a base 2, and a hydraulic chuck mechanism 5, an automatic clamping mechanism 3 and at least two rotating support mechanisms 4 are sequentially installed on the base 2.

[0026] The hydraulic chuck mechanism 5 is used to clamp the rod head end of the sucker rod 1 and drive it to rotate around the axis. The automatic clamping mechanism 3 is used to center and clamp the rod body. The rotating support mechanism 4 is used to provide auxiliary support near the rod tail.

[0027] The automatic clamping mechanism 3 includes a slide table 31, which can slide in the area between the hydraulic chuck mechanism 5 and the rotating support mechanism 4 to adjust the centering and clamping area of ​​the sucker rod 1. By adjusting the position of the slide table 31, it can accommodate sucker rods of different lengths, ensuring that the clamping point is always in the optimal support position, thereby effectively reducing vibration during processing and improving the thread machining accuracy.

[0028] Two support arms 36 are fixedly mounted side by side on the slide table 31. The top ends of the two support arms 36 are rotatably connected to an upper rotating shaft 38 and a lower rotating shaft 39. Gears 310 are fixedly mounted on both the upper rotating shaft 38 and the lower rotating shaft 39. The two gears 310 mesh with each other to enable the upper rotating shaft 38 and the lower rotating shaft 39 to rotate synchronously in opposite directions. An upper swing arm 311 is vertically fixed to the top of the upper rotating shaft 38, and a lower swing arm 312 is vertically fixed to the bottom of the lower rotating shaft 39.

[0029] The upper swing arm 311 has a pressure roller 313 rotatably mounted on its top and bottom, and the lower swing arm 312 has two rollers A314 arranged side by side mounted on its bottom. The pressure roller 313 and the two rollers A314 together form a centering and clamping structure for the sucker rod 1.

[0030] The bottom end of the lower swing arm 312 is a U-shaped bracket structure. The roller A314 is rotatably mounted on the rotating shaft. Both ends of the rotating shaft are provided with mounting platforms. The U-shaped bracket structure has an opening slot that matches the mounting platforms at both ends of the rotating shaft. The rotating shaft can be easily installed into or removed from the U-shaped bracket through the opening slot, thereby greatly improving the replacement efficiency of the roller A314.

[0031] The upper swing arm 311 is hinged to the head of the cylinder 315 at one end away from the pressure roller 313, and the tail of the cylinder 315 is hinged to the hinge shaft 317; the two ends of the hinge shaft 317 are respectively installed on the ear seats 316 correspondingly provided on the sides of the two support arms 36.

[0032] A compressed air station 37 is fixedly installed on the slide table 31. The compressed air station 37 moves with the slide table 31. The compressed air station 37 is located on the side of the support arm 36. The compressed air station 37 is connected to the cylinder 315 through a pipeline to provide power to it. The cylinder 315 realizes the clamping and releasing action of the automatic clamping mechanism 3.

[0033] The bottom of the slide table 31 is slidably connected to the base 2 via a slider 32 and a linear slide rail 33. The slider 32 is fixedly installed at the bottom of the slide table 31, and the linear slide rail 33 is fixedly installed on the upper surface of the base 2. A lead screw nut 34 is fixedly installed at the middle position of the bottom of the slide table 31, and a lead screw 35 with threaded engagement is installed inside the lead screw nut 34. The lead screw 35 is arranged along the axial direction of the base 2, and its two ends are rotatably supported on the base 2 through bearing seats. One end of the lead screw 35 is connected to a drive motor.

[0034] The drive motor drives the lead screw 35 to rotate, and the lead screw nut 34 converts the rotational motion of the lead screw 35 into the linear reciprocating motion of the slide table 31 along the linear slide rail 33, thereby realizing the precise adjustment of the position of the automatic clamping mechanism 3 on the base 2.

[0035] The rotating support mechanism 4 includes a V-shaped lifting seat 41, on which two rollers B42 are installed side by side. The lifting seat 41 is fixedly installed on the lifting platform 43, which is located directly above the support box 45. The support box 45 is fixedly installed on the base 2.

[0036] The roller B42 is rotatably mounted on the shaft, and both ends of the shaft are provided with mounting platforms. The lifting seat 41 has an opening slot that matches the mounting platforms at both ends of the shaft. The shaft can be easily installed into or removed from the lifting seat 41 through the opening slot, thereby greatly improving the replacement efficiency of the roller B42.

[0037] A worm gear screw jack 47 is installed between the lifting platform 43 and the support box 45. At least two vertically arranged slide rods 44 are fixedly installed at the bottom of the lifting platform 43, and a linear bearing 46 is provided at the connection between the slide rod 44 and the top wall of the support box 45. The slide rod 44 and the linear bearing 46 are in sliding fit.

[0038] The worm gear screw jack 47 drives the lifting platform 43 to move up and down vertically. The slide bar 44 moves synchronously with the lifting platform 43 and slides within the linear bearing 46, thus ensuring the stability and straightness of the lifting platform 43 during the lifting process. By adjusting the height of the lifting platform 43, it can accommodate sucker rods 1 of different diameters, achieving reliable rotational support for the sucker rods 1.

[0039] The specific working principle of this invention: I. Preparation: Adjust the device according to the workpiece specifications. Slide position adjustment (adapting to rod length): The drive motor drives the lead screw 35 to rotate, and the lead screw nut 34 converts the rotational motion into the linear reciprocating motion of the slide 31 along the linear slide rail 33, so that the entire automatic clamping mechanism 3 moves axially on the base 2 to adapt to sucker rods 1 of different lengths and ensure that the clamping point is in the optimal support position.

[0040] Rotary support height adjustment (adapting to rod diameter): The worm gear screw jack 47 drives the lifting platform 43 to rise and fall vertically, and the slide bar 44 cooperates with the linear bearing 46 to ensure smooth lifting. By adjusting the height of the lifting platform 43, the two rollers B42 on the V-shaped lifting seat 41 lift the sucker rod 1 to a suitable height to accommodate sucker rods of different diameters.

[0041] II. Automatic centering and clamping: gear linkage and pneumatic coordination The cylinder pushes the upper swing arm: the piston rod of the cylinder 315 extends, and the upper swing arm 311, which is hinged to the end of the piston rod, swings around the upper pivot 38.

[0042] Gears rotate synchronously in opposite directions: When the upper rotating shaft 38 rotates, the gear 310 fixed on it drives the gear 310 on the lower rotating shaft 39 to rotate synchronously in opposite directions, so that the lower swing arm 312 and the upper swing arm 311 swing towards each other at the same time.

[0043] The pressure roller and the roller form a centering clamp: the pressure roller 313 at the bottom of the top of the upper swing arm 311 presses down on the upper surface of the sucker rod 1; the two parallel rollers A314 at the bottom of the lower swing arm 312 support the lower surface of the sucker rod 1 from below; the pressure roller 313 and the two rollers A314 form a triangular centering structure to achieve automatic centering clamping of the sucker rod.

[0044] III. Processing status: Combination of rotary drive and support The hydraulic chuck mechanism 5 clamps the rod head of the sucker rod 1 and drives it to rotate around its axis. The pressure roller 313 and roller A314 of the automatic clamping mechanism 3 clamp the rod body, providing only radial clamping force and not hindering the rotation of the sucker rod 1. The roller B42 of the rotation support mechanism 4 provides auxiliary support near the rod tail, ensuring the stability of the long rod during rotation. The three mechanisms work together to significantly reduce vibration and chatter during the machining of the sucker rod 1, thereby ensuring the machining accuracy of the external thread of the rod head. It can significantly improve the surface finish, dimensional accuracy, and coaxiality of the thread, and is suitable for batch CNC machining of sucker rod heads with diameters of Φ16-Φ29mm.

[0045] The above description provides examples of the preferred embodiments of the present invention. Parts not detailed herein are common knowledge to those skilled in the art. The scope of protection of the present invention is determined by the claims. Any equivalent modifications based on the technical teachings of the present invention are also within the scope of protection of the present invention.

Claims

1. An automatic centering and clamping device for machining the external thread of a sucker rod head, characterized in that: The base (2) includes a hydraulic chuck mechanism (5), an automatic clamping mechanism (3), and at least two rotating support mechanisms (4) installed sequentially on top of the base (2). The automatic clamping mechanism (3) includes a slide (31) that can slide in the area between the hydraulic chuck mechanism (5) and the rotating support mechanism (4). Two support arms (36) are fixedly installed on the slide (31) and arranged side by side. The top ends of the two support arms (36) are rotatably connected to an upper rotating shaft (38) and a lower rotating shaft (39). The upper rotating shaft (38) and the lower rotating shaft (39) are rotatably connected to each other. Gears (310) are fixedly installed on the rotating shaft (39), and the two gears (310) mesh with each other. The top of the upper rotating shaft (38) is vertically fixed to the upper swing arm (311), and the bottom of the lower rotating shaft (39) is vertically fixed to the lower swing arm (312). The top and bottom of the upper swing arm (311) are rotatably mounted with a pressure roller (313), and the bottom of the lower swing arm (312) is mounted with two rollers A (314) arranged side by side. The pressure roller (313) and the two rollers A (314) together form a centering and clamping structure for the sucker rod (1).

2. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 1, characterized in that: The bottom end of the lower swing arm (312) is a U-shaped bracket structure. The roller A (314) is rotatably mounted on the rotating shaft. Both ends of the rotating shaft are provided with mounting surfaces. The U-shaped bracket structure has openings that are compatible with the mounting surfaces at both ends of the rotating shaft.

3. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 1, characterized in that: The upper swing arm (311) is hinged to the head of the cylinder (315) at one end away from the pressure roller (313), and the tail of the cylinder (315) is hinged to the hinge shaft (317); the two ends of the hinge shaft (317) are respectively installed on the ear seats (316) correspondingly provided on the sides of the two support arms (36).

4. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 1, characterized in that: A compressed air station (37) is fixedly installed on the slide (31). The compressed air station (37) moves with the slide (31). The compressed air station (37) is located on the side of the support arm (36). The compressed air station (37) is connected to the cylinder (315) through a pipeline.

5. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 1, characterized in that: The bottom of the slide table (31) is slidably connected to the base (2) through a slider (32) and a linear slide rail (33). The slider (32) is fixedly installed at the bottom of the slide table (31), and the linear slide rail (33) is fixedly installed on the upper surface of the base (2).

6. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 5, characterized in that: A lead screw nut (34) is fixedly installed at the middle position of the bottom of the slide (31). A lead screw (35) with threaded engagement is installed inside the lead screw nut (34). The lead screw (35) is arranged along the axial direction of the base (2). Its two ends are rotatably supported on the base (2) through bearing seats. One end of the lead screw (35) is connected to a drive motor.

7. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 1, characterized in that: The rotating support mechanism (4) includes a V-shaped lifting seat (41) on which two rollers B (42) are installed side by side.

8. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 7, characterized in that: Roller B (42) is rotatably mounted on a rotating shaft. Both ends of the rotating shaft are provided with mounting platforms. The lifting seat (41) has an opening groove that matches the mounting platforms at both ends of the rotating shaft.

9. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 7, characterized in that: The lifting seat (41) is fixedly installed on the lifting platform (43), which is located directly above the support box (45). The support box (45) is fixedly installed on the base (2).

10. The automatic centering and clamping device for machining the external thread of the sucker rod head as described in claim 9, characterized in that: A worm gear screw jack (47) is installed between the lifting platform (43) and the support box (45). At least two slide rods (44) are fixedly installed at the bottom of the lifting platform (43) along the vertical direction. A linear bearing (46) is provided at the connection between the slide rod (44) and the top wall of the support box (45). The slide rod (44) and the linear bearing (46) are in sliding cooperation.

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