A constant force rolling tool and rolling method for external thread root and end

Abstract

The present invention discloses a constant force rolling tool and rolling method for the root and end of external threads. The tool includes a rolling tool head, a pressure sensor, an electromagnetic force device, a cover plate, a tool handle, a laser sensor, and a magnet. Since the present invention uses an electromagnetic force device to utilize Ampere force to drive a rolling wheel to roll high-strength bolts, the rolling wheel generates rolling pressure on the root of the thread, ensuring that the uniform magnetic field strength B and the length L of the conductor rod remain unchanged. Before rolling begins, the pressure sensor feeds back the pressure magnitude to the voltage controller. The voltage controller ensures that the magnitude of the current I reaches the set value by changing the voltage magnitude. According to F 安 =BIL, ensuring constant rolling force during rolling. This invention uses a laser sensor, and the turret controller automatically calculates the retraction position based on the feed speed and position information fed back by the laser sensor. This ensures that the retraction command is executed only after the rolling tool has rolled the entire thread end, improving rolling accuracy and efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of thread rolling strengthening, in particular to a constant force rolling tool and a rolling method for external thread root and end. Background Art

[0002] High-strength bolts widely used on helicopters are made from high-strength steels such as 35Cr2Ni4MoA and 30CrNi4MoA. High-strength bolts are subject to extreme environments and are prone to fatigue failure. Rolling is the primary method for strengthening bolt surfaces. Under the pressure applied by the rolling wheel, the metal on the bolt surface undergoes continuous localized plastic deformation, producing cold work hardening and residual compressive stresses. Rolling is also a chipless process that provides both smoothing and surface strengthening. Experiments have shown that the fatigue life of high-strength bolts after rolling is significantly improved.

[0003] However, at present, ordinary lathes are usually used to roll the thread roots and tails of high-strength bolts in China. The rolling force is difficult to maintain constant, resulting in poor consistency of fatigue life although the fatigue life of the bolts is improved after rolling. At present, most of the domestic rolling processes are controlled by programs or manually. Since the national standard stipulates that the thread tail is a numerical range, if the rolling process is controlled by a program, the tail length of each bolt needs to be measured, and the program needs to be changed according to the measured value, which greatly increases the workload. If the rolling process is controlled manually, the rolling accuracy decreases and the rolling efficiency is low. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention aims to design a constant force rolling tool and rolling method for the root and end of external threads, which can achieve constant rolling force when rolling high-strength bolts and complete the entire rolling process with high precision and high efficiency.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A constant force rolling tool for external thread roots and finishes, comprising a rolling tool head, a pressure sensor, an electromagnetic force device, a cover plate, a tool handle, a laser sensor, and a magnet. The rolling tool head is elastically connected to the electromagnetic force device; the electromagnetic force device is slidably connected to an outer box, and the outer box and tool handle are an integral structure.

[0007] The rolling cutter head includes a rolling wheel, a bearing, a rolling core shaft, a gasket, a fork frame and a pressure plate. The upper section of the fork frame is a U-shaped structure, and the lower section is a cylindrical structure. The two ends of the rolling core shaft are respectively mounted on both sides of the U-shaped structure through bearings; the rolling wheel is sleeved on the rolling core shaft; a gasket is arranged between the right side of the rolling wheel and the bearing, and the pressure plate and the fork frame are mounted on the left side of the U-shaped structure through countersunk screws;

[0008] The lower section of the rolling cutter head is nested in the upper end of the push rod through a spring and elastically connected to the push rod through a bolt;

[0009] The spring is nested in the upper end of the push rod; the top of the spring contacts the bearing plate; the pressure sensor is fixed on the bearing plate;

[0010] The electromagnetic force device includes a push rod, a cover plate, a conductor rod, an inner box, an anode plate and a cathode plate; the push rod and the inner box are an integral structure;

[0011] There are two anode plates, which are symmetrically fixed to the left side of the inner box, and the anode plates are in contact with the left side of the conductor rod;

[0012] There are two cathode plates, which are symmetrically fixed to the right side of the inner box, and are in contact with the right side of the conductor rod.

[0013] The two ends of the conductor rod pass through the side wall of the inner box and contact the anode plate and the cathode plate respectively;

[0014] The outer side of the inner box is slidably connected to the inner side of the outer box;

[0015] A rubber gasket is provided between the bottom of the inner box and the bottom of the outer box;

[0016] The center of the rubber gasket and the center of the bottom of the outer box are both provided with wire holes;

[0017] The top of the outer box is connected to the cover plate by screws; the upper end of the push rod passes through the cover plate and is elastically connected to the fork frame;

[0018] Magnets are provided on the front and rear sides of the outer box, and the magnets are fixedly connected to the front and rear sides of the outer box respectively.

[0019] A laser sensor is fixedly installed on the outer side of the outer box.

[0020] Furthermore, a slide groove is provided on the inner side of the outer box, and a slider is provided on the outer side of the inner box, and the slider slides up and down along the slide groove.

[0021] Furthermore, the two anode plates have the same structure, are symmetrically positioned front to back, and are connected to the inner box via rivets; the two cathode plates have the same structure, are symmetrically positioned front to back, and are connected to the inner box via rivets.

[0022] Furthermore, the conductor bars are arranged in multiple rows, with multiple conductor bars in each row, and each conductor bar has the same structure. The multiple rows of conductor bars are installed in the inner box along the up and down direction.

[0023] Furthermore, gaps are left between the upper portion of the inner box and the cover plate, and between the lower portion and the rubber gasket.

[0024] Furthermore, the anode plate and the cathode plate are respectively connected to power supply wires through wire holes.

[0025] A rolling method using a constant force rolling tool for external thread roots and finishes, comprising the following steps:

[0026] A. The magnets on the front and back of the outer box generate a uniform magnetic field, with the front of the outer box as the N pole and the back as the S pole; the anode plate and cathode plate are connected to the positive and negative poles of the power supply respectively; when the automatic tool setting device completes the tool setting, the turret drives the rolling tool to enter the first thread root;

[0027] B. The rolling tool is placed in a uniform magnetic field. When the power is turned on, the electromagnetic force device starts to operate, the conductor rod generates an Ampere force, which drives the push rod to generate thrust, and the rolling wheel generates rolling force on the thread root. Before rolling begins, the pressure sensor feeds back the pressure magnitude to the voltage controller. The voltage controller changes the voltage magnitude to make the current I reach the set value, and then the rolling tool starts rolling. During the rolling process, the turret moves along the axial direction of the bolt to achieve rolling of the thread root.

[0028] C. The laser sensor emits a laser to the bolt, and the laser reflected by the bolt is received by the laser sensor. The time difference between the laser sensor's emission and reception of the laser is used to reflect the diameters of the thread end, the bolt retraction groove, and the bolt polished rod. The laser sensor senses the position of the thread end at the point where the diameter changes, and the laser sensor feeds back the position information to the turret controller. The turret controller automatically calculates the retraction position based on the feed speed and the position information fed back by the laser sensor. When the turret reaches the retraction position, it automatically retracts the tool, and the rolling process ends.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. Since the present invention uses an electromagnetic force device to use Ampere force to drive the rolling wheel to roll the high-strength bolt, the rolling wheel generates rolling pressure on the thread bottom to ensure that the uniform magnetic field strength B and the length L of the conductor rod remain unchanged. Before rolling begins, the pressure sensor feeds back the pressure size to the voltage controller. The voltage controller ensures that the current I reaches the set value by changing the voltage size. According to F 安 =BIL, which ensures that the rolling force remains constant during the rolling process;

[0031] 2. Since the present invention uses a laser sensor to emit laser to the bolt, the laser sensor senses the position of the thread end at the diameter change, and the laser sensor feeds back the position information to the turret controller. The turret controller automatically calculates the position of the tool retraction based on the feed speed and the position information fed back by the laser sensor, so that the tool retraction command will not be executed until the rolling tool has completed rolling the entire thread end, thereby improving the rolling accuracy and rolling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the present invention (the magnet part is not shown);

[0033] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0034] Figure 3 yes Figure 2 Right view;

[0035] Figure 4 yes Figure 1 AA cross-sectional view of ;

[0036] Figure 5 yes Figure 4 A partial enlarged schematic diagram of point C;

[0037] Figure 6 yes Figure 1 BB cross-sectional diagram;

[0038] Figure 7 yes Figure 1 A local enlarged schematic diagram of point D;

[0039] Figure 8 yes Figure 1 Schematic diagram of the E-direction structure of the inner box;

[0040] Figure 9 It is a schematic diagram of the working principle of the present invention.

[0041] In the figure: 1- rolling wheel; 2- bearing; 3- rolling mandrel; 4- gasket; 5- pressure sensor; 6- spring; 7- push rod; 8- cover plate; 9- conductor rod; 10- tool handle; 11- wire hole; 12- rubber gasket; 13- outer box; 1301- slide groove; 14- inner box; 1401- slider; 15- laser sensor; 16- load plate; 17- fork frame; 18- pressure plate; 19- countersunk screw; 20- anode plate; 21- cathode plate; 22- magnet. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings. Figure 1-9 As shown, a constant force rolling tool for the root and end of an external thread includes a rolling cutter head, a pressure sensor 5, an electromagnetic force device, a cover plate 8, a tool handle 10, a laser sensor 15, and a magnet 22. The rolling cutter head is elastically connected to the electromagnetic force device; the electromagnetic force device is slidably connected to an outer box 13, and the outer box 13 and the tool handle 10 are an integral structure.

[0043] The rolling cutter head includes a rolling wheel 1, a bearing 2, a rolling mandrel 3, a gasket 4, a fork frame 17 and a pressure plate 18. The upper section of the fork frame 17 is a U-shaped structure, and the lower section is a cylindrical structure. The two ends of the rolling mandrel 3 are respectively mounted on both sides of the U-shaped structure through bearings 2; the rolling wheel 1 is sleeved on the rolling mandrel 3; a gasket 4 is arranged between the right side of the rolling wheel 1 and the bearing 2, and the pressure plate 18 and the fork frame 17 are mounted on the left side of the U-shaped structure through countersunk screws 19;

[0044] The lower section of the rolling cutter head is nested in the upper end of the push rod 7 through the spring 6 and is elastically connected to the push rod 7 through bolts;

[0045] The spring 6 is nested in the upper end of the push rod 7; the top of the spring 6 is in contact with the bearing plate 16; the pressure sensor 5 is fixed on the bearing plate 16;

[0046] The electromagnetic force device includes a push rod 7, a cover plate 8, a conductor rod 9, an inner box 14, an anode plate 20 and a cathode plate 21; the push rod 7 and the inner box 14 are an integral structure;

[0047] There are two anode plates 20, which are symmetrically fixed to the left side of the inner box 14, and the anode plates 20 are in contact with the left side of the conductor rod 9;

[0048] There are two cathode plates 21, which are symmetrically fixed to the right side of the inner box 14. The cathode plates 21 are in contact with the right side of the conductor rod 9.

[0049] The two ends of the conductor rod 9 pass through the side wall of the inner box 14 and contact the anode plate 20 and the cathode plate 21 respectively;

[0050] The outer side of the inner box 14 is slidably connected to the inner side of the outer box 13;

[0051] A rubber gasket 12 is provided between the bottom of the inner box 14 and the bottom of the outer box 13;

[0052] The center of the rubber gasket 12 and the center of the bottom of the outer box 13 are both opened with a wire hole 11;

[0053] The top of the outer box 13 is connected to the cover plate 8 by screws; the upper end of the push rod 7 passes through the cover plate 8 and is elastically connected to the fork frame 17;

[0054] Magnets 22 are provided on the front and rear sides of the outer box 13 , and the magnets 22 are fixedly connected to the front and rear sides of the outer box 13 , respectively.

[0055] A laser sensor 15 is fixedly mounted on the outer side of the outer box 13 .

[0056] Furthermore, a slide groove 1301 is provided on the inner side of the outer box 13 , and a slider 1401 is provided on the outer side of the inner box 14 , and the slider 1401 slides up and down along the slide groove 1301 .

[0057] Furthermore, the two anode plates 20 have the same structure, are symmetrically positioned front to back, and are connected to the inner box 14 via rivets; the two cathode plates 21 have the same structure, are symmetrically positioned front to back, and are connected to the inner box 14 via rivets.

[0058] Furthermore, the conductor bars 9 are arranged in multiple rows, with multiple conductor bars in each row. Each conductor bar 9 has the same structure, and the multiple rows of conductor bars 9 are installed in the inner box 14 along the up and down direction.

[0059] Furthermore, there are gaps between the upper portion of the inner box 14 and the cover plate 8 , and between the lower portion of the inner box 14 and the rubber gasket 12 .

[0060] Furthermore, the anode plate 20 and the cathode plate 21 are respectively connected to power supply wires through the wire holes 11.

[0061] A rolling method using a constant force rolling tool for external thread roots and finishes, comprising the following steps:

[0062] A. The magnets 22 on the front and rear sides of the outer box 13 generate a uniform magnetic field, with the front side of the outer box 13 being the N pole and the rear side being the S pole; the anode plate 20 and the cathode plate 21 are connected to the positive and negative poles of the power supply respectively; when the automatic tool setting device completes the tool setting, the turret drives the rolling tool to enter the first thread root;

[0063] B. The rolling tool is within a uniform magnetic field. When the power is turned on, the electromagnetic force device starts to operate, the conductor rod 9 generates an Ampere force, which drives the push rod 7 to generate thrust, and the rolling wheel 1 generates a rolling force on the thread root. Before rolling begins, the pressure sensor feeds back the pressure magnitude to the voltage controller. The voltage controller changes the voltage magnitude to make the current I reach the set value, and then the rolling tool starts rolling. During the rolling process, the turret moves along the axial direction of the bolt to achieve rolling of the thread root.

[0064] C. The laser sensor 15 emits a laser at the bolt, and the laser reflected by the bolt is received by the laser sensor 15. The time difference between the laser sensor 15 emitting and receiving the laser is used to reflect the diameters of the thread end, the bolt retraction groove, and the bolt polished rod. The laser sensor 15 senses the position of the thread end at the diameter change point, and the laser sensor 15 feeds back the position information to the turret controller. The turret controller automatically calculates the retraction position based on the feed speed and the position information fed back by the laser sensor 15. When the turret reaches the retraction position, it automatically retracts the tool, and the rolling process ends.

[0065] For the convenience of description, the terms "up", "down", "left", "right", "front" and "back" in the present invention are only relative. Figure 1 , does not limit the structure, but is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0066] The present invention is not limited to this embodiment, and any equivalent concepts or modifications within the technical scope disclosed by the present invention are included in the protection scope of the present invention.

Claims

1. A constant force rolling tool for external thread roots and finishes, characterized by: The invention comprises a rolling cutter head, a pressure sensor (5), an electromagnetic force device, a cover plate (8), a cutter handle (10), a laser sensor (15) and a magnet (22), wherein the rolling cutter head is elastically connected to the electromagnetic force device; the electromagnetic force device is slidably connected to an outer box (13), and the outer box (13) and the cutter handle (10) are an integral structure; The rolling cutter head comprises a rolling wheel (1), a bearing (2), a rolling core shaft (3), a gasket (4), a fork frame (17) and a pressure plate (18); the upper section of the fork frame (17) is a U-shaped structure, and the lower section is a cylindrical structure; the two ends of the rolling core shaft (3) are respectively mounted on the two sides of the U-shaped structure through bearings (2); the rolling wheel (1) is sleeved on the rolling core shaft (3); a gasket (4) is provided between the right side of the rolling wheel (1) and the bearing (2); the pressure plate (18) and the fork frame (17) are mounted on the left side of the U-shaped structure through countersunk screws (19); The lower section of the rolling cutter head is nested in the upper end of the push rod (7) via a spring (6) and is elastically connected to the push rod (7) via a bolt; The spring (6) is nested in the upper end of the push rod (7); the top of the spring (6) is in contact with the bearing plate (16); the pressure sensor (5) is fixed on the bearing plate (16); The electromagnetic force device comprises a push rod (7), a cover plate (8), a conductor rod (9), an inner box (14), an anode plate (20) and a cathode plate (21); the push rod (7) and the inner box (14) are an integral structure; There are two anode plates (20), which are fixedly connected to the left side of the inner box (14) in a front-to-back symmetrical manner, and the anode plates (20) are in contact with the left side of the conductor rod (9); There are two cathode plates (21), which are fixedly connected to the right side of the inner box (14) in a front-to-back symmetrical manner, and the cathode plates (21) are in contact with the right side of the conductor rod (9); The two ends of the conductor rod (9) pass through the side wall of the inner box (14) and are in contact with the anode plate (20) and the cathode plate (21) respectively; The outer side of the inner box (14) is slidably connected to the inner side of the outer box (13); A rubber gasket (12) is provided between the bottom of the inner box (14) and the bottom of the outer box (13); A wire hole (11) is simultaneously opened at the center of the rubber gasket (12) and the center of the bottom of the outer box (13); The top of the outer box (13) is connected to the cover plate (8) by screws; the upper end of the push rod (7) passes through the cover plate (8) and is elastically connected to the fork frame (17); The front and rear sides of the outer box (13) are both provided with magnets (22), and the magnets (22) are fixedly connected to the front and rear sides of the outer box (13) respectively; A laser sensor (15) is fixedly mounted on the outer side of the outer box (13).

2. A constant force rolling tool for external thread roots and finishes according to claim 1, characterized in that: A slide groove (1301) is provided on the inner side of the outer box (13), and a slider (1401) is provided on the outer side of the inner box (14), and the slider (1401) slides up and down along the slide groove (1301).

3. A constant force rolling tool for external thread roots and finishes according to claim 1, characterized in that: The two anode plates (20) have the same structure and are symmetrically positioned front to back, and are connected to the inner box (14) through rivets; the two cathode plates (21) have the same structure and are symmetrically positioned front to back, and are connected to the inner box (14) through rivets.

4. A constant force rolling tool for external thread roots and finishes according to claim 1, characterized in that: The conductor bars (9) are arranged in multiple rows, with multiple conductor bars in each row. Each conductor bar (9) has the same structure. The multiple rows of conductor bars (9) are installed in the inner box (14) along the vertical direction.

5. A constant force rolling tool for external thread roots and finishes according to claim 1, characterized in that: Gaps are left between the upper part of the inner box (14) and the cover plate (8), and between the lower part and the rubber gasket (12).

6. A constant force rolling tool for external thread roots and finishes according to claim 1, characterized in that: The anode plate (20) and the cathode plate (21) are respectively connected to power supply wires through wire holes (11).

7. A rolling method using a constant force rolling tool for external thread roots and finishes according to any one of claims 1 to 6, characterized in that: The following steps are involved: A. The magnets (22) on the front and rear sides of the outer box (13) generate a uniform magnetic field, with the front side of the outer box (13) being the N pole and the rear side being the S pole; the anode plate (20) and the cathode plate (21) are connected to the positive and negative poles of the power supply respectively; when the automatic tool setting device completes the tool setting, the turret drives the rolling tool to enter the first thread root; B. The rolling tool is in a uniform magnetic field, the power is turned on, the electromagnetic force device starts to work, the conductor rod (9) generates an Ampere force, the conductor rod (9) drives the push rod (7) to generate thrust, and the rolling wheel (1) generates rolling pressure on the thread bottom; before rolling starts, the pressure sensor feeds back the pressure size to the voltage controller, and the voltage controller changes the voltage size so that the current I reaches the set value, and then the rolling tool starts rolling. During the rolling process, the turret moves along the axial direction of the bolt to achieve rolling of the thread bottom; C. The laser sensor (15) emits a laser to the bolt, and the laser reflected by the bolt is received by the laser sensor (15). The time difference between the laser sensor (15) emitting and receiving the laser is used to reflect the diameters of the thread end, the bolt retraction groove, and the bolt polished rod. The laser sensor (15) senses the position of the thread end at the diameter change point, and the laser sensor (15) feeds back the position information to the turret controller. The turret controller automatically calculates the retraction position based on the feed speed and the position information fed back by the laser sensor (15). When the turret reaches the retraction position, the tool is automatically retracted, and the rolling process ends.

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