Double-head spinning machine and steel pipe wall reduction method

Abstract

The present invention discloses a double-head spinning machine, which includes a base, a rotating mechanism, a clamping support mechanism and a spinning wheel mechanism arranged thereon, wherein the spinning wheel mechanism is arranged on both sides of the rotating mechanism, and the clamping support mechanism is arranged on both sides of the spinning wheel mechanism. A chuck is also provided in the rotating mechanism. When a product is placed in the rotating mechanism, the middle of the product is clamped by the chuck, and the two ends of the product are fixed by the clamping support mechanism. The spinning wheel mechanism spins the product, thereby processing both ends of the product at the same time, accelerating production efficiency, and meeting the needs of producing specific products. A steel pipe wall reduction method is also disclosed, which utilizes the principles of radial extrusion and axial extension to thin the wall of a seamless steel pipe. It belongs to a cold spinning process, and the wall thickness of the pipe can be thinned in sections or multiple sections at different positions. The wall thickness processing of the steel pipe can be achieved in a non-cutting state without losing any base material, and the material utilization rate can reach more than 95%.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning machines, and in particular relates to a double-head spinning machine and a steel pipe wall reduction method thereof. Background Art

[0002] Spinning is a special forming method that fixes a flat plate or hollow blank on the mold of a spinning machine. While the blank rotates with the spindle of the machine tool, a rotating wheel or a driving rod is used to apply pressure to the blank to cause local plastic deformation. Spinning can be used to complete processes such as drawing, flanging, shrinking, bulging and curling of rotating bodies of various shapes.

[0003] Most of the existing spinning machines are single-head. When double-head processing of a product is required, the spinning needs to be divided into two steps, which is inefficient.

[0004] Furthermore, the tube blanks for integrated automotive axle housings are significantly reduced in diameter. This reduction typically increases the wall thickness by 45% to 55%, significantly increasing the weight and cost of the tube. To address this significant reduction and increased wall thickness, the typical solution is to add an internal drawing mandrel. However, this process has proven to be problematic and unsuitable for mass production. Common issues include: 1. Overdrawing damages the steel tube's material properties; 2. Due to its wear-resistant structure, the mold life is shortened; 3. Seizures are common; and 4. Cost is prohibitive. Summary of the Invention

[0005] In order to solve the problem that the existing spinning machine cannot operate with two heads, the present invention provides a double-head spinning machine that improves production efficiency and meets process requirements.

[0006] The technical solution of the present invention is:

[0007] The present invention discloses a double-head spinning machine, which is electrically connected to a numerical control system and includes a base, and a rotating mechanism, a clamping support mechanism and a spinning wheel mechanism arranged thereon. The spinning wheel mechanism is arranged on both sides of the rotating mechanism, and the clamping support mechanism is arranged on both sides of the spinning wheel mechanism. A chuck is also provided in the rotating mechanism. When a product is placed in the rotating mechanism, the middle of the product is clamped by the chuck, and the two ends of the product are fixed by the clamping support mechanism. The spinning wheel mechanism spins the product.

[0008] Furthermore, the rotating mechanism is a hydraulic rotating device, the chuck is arranged in the middle of the hydraulic rotating device, and the product is driven to rotate through the hydraulic rotating device.

[0009] Furthermore, the clamping support mechanism includes a hydraulic cylinder, a tailstock and a mold core rod. The tailstock is arranged between the hydraulic cylinder and the mold core rod. The hydraulic cylinder drives the mold core rod on the tailstock to perform horizontal axial movement and extend the mold core rod into or out of the product.

[0010] Furthermore, the spinning wheel mechanism includes a fixed frame, a movable rod, a spinning wheel and a hydraulic device, one end of the movable rod is arranged on the inner side of the top of the fixed frame, the spinning wheel is arranged at the other end of the movable rod, the hydraulic device is arranged on the top of the fixed frame, and the hydraulic device is connected to the movable rod, and the spinning wheel on the movable rod is driven by the hydraulic device to extrude the product.

[0011] Furthermore, the spinning wheel mechanism also includes a guide rail, a ball screw, a support seat and a servo motor. The guide rail is arranged on the base and connected to the fixed frame. The support seat and the servo motor are arranged at both ends of the ball screw. The ball screw is arranged on the side of the guide rail. The ball screw penetrates into the fixed frame and is driven by the servo motor to drive the fixed frame to move horizontally axially.

[0012] Furthermore, a ball nut is provided in the fixing frame, and the ball screw penetrates the ball nut, and the fixing frame is driven to move by the movement of the ball nut.

[0013] Furthermore, a nozzle is provided on the side of the movable rod, and lubricating coolant is sprayed to the spinning wheel through the nozzle.

[0014] In order to solve the problem that the existing pipes are subjected to large-scale diameter reduction, resulting in increased wall thickness and complicated process steps, a steel pipe wall reduction method is provided, comprising the following steps:

[0015] Step 1: Place the steel pipe in the rotary mechanism of the double-head spinning machine, adjust the position of the steel pipe, and close the chuck to lock the middle of the steel pipe;

[0016] Step 2: Control the spinning wheel mechanism to quickly shift and move it to the upper sides of the clamping position of the steel pipe;

[0017] Step 3: The clamping support mechanism fixes both ends of the steel pipe, and the core rod in the mold is inserted into the steel pipe with the help of the hydraulic cylinder;

[0018] Step 4: The rotary mechanism drives the steel pipe to start rotating, and the core rod in the mold rotates passively under the drive of the steel pipe;

[0019] Step 5: Extend the movable rod and the spinning wheel at a uniform speed to the set extrusion position, and extrude the outer diameter of the steel pipe in three directions on both sides simultaneously. At the same time, the nozzle is opened and coolant is started to be filled into the spinning wheel.

[0020] Step 6: The servo motor starts to drive the double-sided ball screw to rotate counterclockwise at a uniform speed. Under the rotation of the double-sided ball screw, the double-sided ball nut, together with the spinning wheel mechanism, begins to perform a double-sided outward uniform axial reduction and wall thickness feeding action on the outer diameter of the steel pipe;

[0021] Step 7: The CNC system controls the movable rod and the spinning wheel to retract to the starting position, and the fixed frame also quickly moves to the starting position;

[0022] Step 8: The rotation of the rotary mechanism stops, and the bilateral hydraulic cylinders uniformly pull the core rods in the bilateral mold out from the inside of both ends of the steel pipe and return them to the starting position;

[0023] Step 9: The chuck inside the rotary mechanism loosens the steel pipe by controlling the hydraulic power through the numerical control system, and the steel pipe is taken out, and the double-end wall reduction of the steel pipe is completed.

[0024] Furthermore, in step 2, the servo motor is controlled by the numerical control system to start driving the bilateral ball screw to rotate rapidly clockwise. The fixed frame shifts when the ball screw and the servo motor provide power, and at the same time, the spinning wheel on the movable rod can move to the top of the steel pipe.

[0025] Furthermore, in step 7, under the control of the CNC system, the hydraulic device controls the movable rod and the spinning wheel to retract, and the bilateral servo motors drive the bilateral ball screws to rotate rapidly counterclockwise. Under the rotation of the bilateral ball screws, the bilateral ball nuts and the spinning wheel mechanism move rapidly axially to the starting position.

[0026] The beneficial effect of the present invention is that a double-head spinning machine is designed, which includes a base, and a rotating mechanism, a clamping support mechanism and a spinning wheel mechanism arranged thereon, the spinning wheel mechanism is arranged on both sides of the rotating mechanism, the clamping support mechanism is arranged on both sides of the spinning wheel mechanism, and a chuck is also provided in the rotating mechanism. The product is placed in the rotating mechanism, the middle of the product is clamped by the chuck, and the two ends of the product are fixed by the clamping support mechanism. The spinning wheel mechanism spins the product, thereby processing both ends of the product at the same time, accelerating production efficiency, and meeting the needs of producing specific products; a steel pipe wall reduction method is also disclosed, which uses the principles of radial extrusion and axial extension to thin the wall of a seamless steel pipe, which belongs to a cold spinning process. This model can thin the wall thickness of the pipe in sections or multiple sections at different positions, and can achieve non-cutting processing for the wall thickness of the steel pipe without losing any base material, and the material utilization rate can reach more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a front view of a double-head spinning machine according to the present invention;

[0028] Figure 2 A top view of a double-head spinning machine according to the present invention;

[0029] Figure 3 This is a right side view of a double-head spinning machine of the present invention;

[0030] Figure 4 for Figure 1 AA section plane;

[0031] Figure 5 This is a front view of a double-head spinning machine of the present invention with the fixing frame omitted;

[0032] Figure 6 This is a top view of a double-head spinning machine of the present invention with the fixing frame omitted;

[0033] Figure 7 This is a flow chart of a steel pipe wall reduction method according to the present invention;

[0034] Figure 8 Schematic diagram of the structure of the steel pipe of the present invention;

[0035] Figure 9 A schematic diagram of a steel pipe wall reduction method according to the present invention showing a spinning wheel operating on a steel pipe;

[0036] Figure 10 This is a schematic diagram of the completion of steel pipe wall reduction in a steel pipe wall reduction method of the present invention.

[0037] In the figure, 1 is the base, 2 is the rotary mechanism, 21 is the chuck, 3 is the clamping support mechanism, 31 is the hydraulic cylinder, 32 is the tailstock, 33 is the core rod in the mold, 4 is the spinning wheel mechanism, 41 is the fixed frame, 411 is the ball nut, 42 is the movable rod, 421 is the nozzle, 43 is the spinning wheel, 44 is the hydraulic device, 45 is the guide rail, 46 is the ball screw, 47 is the support seat, 48 is the servo motor, and S is the steel pipe. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings of the present invention.

[0039] Please refer to Figure 1-6 The present invention provides a double-head spinning machine, which is electrically connected to a numerical control system and includes a base 1, a rotating mechanism 2, a clamping and supporting mechanism 3 and a spinning wheel mechanism 4 arranged thereon, wherein the spinning wheel mechanism 4 is arranged on both sides of the rotating mechanism 2, and the clamping and supporting mechanism 3 is arranged on both sides of the spinning wheel mechanism 4. A chuck 21 is also provided in the rotating mechanism 2. When the product is placed in the rotating mechanism 2, the middle of the product is clamped by the chuck 21, and the two ends of the product are fixed by the clamping and supporting mechanism 3, and the spinning wheel mechanism 4 spins the product.

[0040] The rotary mechanism 2 is a hydraulic rotary device, and the chuck 21 is located in the middle of the hydraulic rotary device, which drives the product to rotate through the hydraulic rotary device. The rotary mechanism 2 can also be understood as a hollow rotary cylinder equipped with a hollow chuck. The rotary cylinder is provided with two fan-shaped rotors and stators. The rotor can rotate within a certain angle, less than 360 degrees, generally greater than 270 degrees, and the main shaft does not rotate. The hydraulic oil pipes are connected to both sides of the rotor, one side is filled with oil, and the other side must return oil. When the rotor rotates and collides with the main shaft, it stops, then changes the direction of the channel, and then rotates again, thus reciprocating. The hollow rotary cylinder rotates, and the hollow chuck clamps the product.

[0041] The clamping support mechanism 3 includes a hydraulic cylinder 31, a tailstock 32, and a mold core rod 33. The tailstock 32 is located between the hydraulic cylinder 31 and the mold core rod 33. The hydraulic cylinder 31 drives the mold core rod 33 on the tailstock 32 to perform horizontal axial movement, thereby extending the mold core rod 33 into or out of the product. In addition, the mold core rod 33 can rotate around a fixed axis when subjected to external force.

[0042] The spinning wheel mechanism 4 includes a fixed frame 41, a movable rod 42, a spinning wheel 43 and a hydraulic device 44. One end of the movable rod 42 is arranged on the inner side of the top of the fixed frame 41, and the spinning wheel 43 is arranged at the other end of the movable rod 42. The hydraulic device 44 is arranged on the top of the fixed frame 41, and the hydraulic device 44 is connected to the movable rod 42. The spinning wheel 43 on the movable rod 42 is driven by the hydraulic device 44 to extrude the product.

[0043] The spinning wheel mechanism 4 also includes a guide rail 45, a ball screw 46, a support seat 47 and a servo motor 48. The guide rail 45 is arranged on the base 1, and the guide rail 45 is connected to the fixed frame 41. The support seat 47 and the servo motor 48 are arranged at both ends of the ball screw 46. The ball screw 46 is arranged on the side of the guide rail 45. The ball screw 46 penetrates into the fixed frame 41 and is driven by the servo motor 48 to drive the fixed frame 41 to move horizontally axially.

[0044] A ball nut 41 is provided in the fixing frame 41 , and a ball screw 46 penetrates the ball nut 41 . The fixing frame 41 is driven to move by the movement of the ball nut 41 .

[0045] A nozzle 421 is provided on the side of the movable rod 42 , and lubricating coolant is sprayed to the spinning wheel through the nozzle 421 .

[0046] Reference Figure 7-10 The present invention provides a method for reducing the wall thickness of a steel pipe, using the double-head spinning machine disclosed above, comprising the following steps:

[0047] Step 1: Place the steel pipe S in the rotary mechanism 2. At this time, the chuck 21 is in the open state. After the steel pipe S is adjusted to a reasonable position, the chuck 21 is closed and locked in the middle of the steel pipe S.

[0048] Step 2: The CNC system controls the spinning wheel mechanism 4 to quickly shift to the specified position. That is, the CNC system controls the servo motor 48 to start driving the double-sided ball screw 46 to rotate rapidly clockwise. The fixed frame 41 shifts under the power provided by the ball screw 46 and the servo motor 48, and at the same time, the spinning wheel 43 on the movable rod 42 can move to the top of the steel pipe.

[0049] Step 3: The clamping support mechanism 3 fixes both ends of the steel pipe, that is, the core rod 33 in the mold is inserted into the steel pipe with the help of the hydraulic cylinder 31 and is located at a reasonable position;

[0050] Step 4: The rotary mechanism 2 drives the steel pipe to start rotating, and the core rod 33 in the mold is then driven by the rotation of the steel pipe to perform a passive rotation;

[0051] Step 5: Under the control of the numerical control system, the hydraulic device 44 of the spinning wheel mechanism 4 extends the movable rod 42 and the spinning wheel 43 at a uniform speed to the set extrusion position, and starts to extrude the outer diameter of the steel pipe in three directions on both sides simultaneously. The extrusion depth is the reasonable depth controlled by the system, which can also be said to be the extrusion depth set by the numerical control system. At the same time, the nozzle 421 opens and starts to fill the spinning wheel 43 with coolant;

[0052] Step 6: Under the control of the CNC system, the servo motor 48 starts to drive the double-sided ball screw 46 to rotate counterclockwise at a uniform speed. Under the rotation of the double-sided ball screw 46, the double-sided ball nut 411, together with the fixing frame 41, the movable rod 42, and the spinning wheel 43, begins to perform a double-sided outward uniform axial reduction and wall thickness reduction feeding action on the outer diameter of the steel pipe. The spinning feed speed is controlled by the CNC system until the pipe reaches the required position and the wall thickness reduction action of the steel pipe is completed.

[0053] Step 7: The hydraulic device 44 of the bilateral spinning wheel mechanism 4 controls the movable rod 42 and the spinning wheel 43 to be retracted to the starting position through the numerical control system;

[0054] Step 8: The CNC system controls the spinning wheel mechanism 4 to quickly shift to the starting position. That is, the bilateral servo motors 48, under the control of the CNC system, drive the bilateral ball screws 46 to rotate rapidly counterclockwise. Under the rotation of the bilateral ball screws 46, the bilateral ball nuts 411, together with the fixing frame 41, the movable rod 42, and the spinning wheel 43, move rapidly axially to the starting position.

[0055] Step 9: The rotary mechanism 2 stops rotating under the control of the numerical control system, and the bilateral hydraulic cylinder 31 controls the bilateral mold inner core rod 33 to be withdrawn from the inside of both ends of the steel pipe at a uniform speed and returned to the starting position.

[0056] Step 10: The chuck 21 inside the rotary mechanism 2 loosens the steel pipe by controlling the hydraulic power through the numerical control system, and the steel pipe is taken out, and the double-end wall reduction of the steel pipe is completed.

[0057] In the above steps, the reset step is divided into two steps, and the reset method is explained in detail.

[0058] Reference Figure 8 , the original length of the steel pipe is L1, the inner diameter is d1, and the outer diameter is D1; ​​refer to Figure 10 After the double-end wall reduction of the steel pipe is completed, the length is L2+L+L2, which is longer than L1. The inner diameter remains d1, and the outer diameter is reduced to D2, D1>D2.

[0059] This process uses the principles of radial extrusion and axial extension to thin the wall of seamless steel pipes. It is a cold spinning process. This model can thin the pipe wall thickness in sections or multiple sections at different positions. The steel pipe wall thickness can be processed without cutting, without losing any base material, and the material utilization rate can reach more than 95%.

[0060] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for reducing the wall thickness of a steel pipe, characterized in that: The double-head spinning machine comprises a steel pipe wall reduction method, the double-head spinning machine is electrically connected to a numerical control system, the double-head spinning machine comprises a base and a rotating mechanism, a clamping support mechanism and a spinning wheel mechanism arranged thereon, the spinning wheel mechanism is arranged on both sides of the rotating mechanism, the clamping support mechanism is arranged on both sides of the spinning wheel mechanism, a chuck is further provided in the rotating mechanism, the steel pipe is placed in the rotating mechanism, the middle of the steel pipe is clamped by the chuck, the two ends of the steel pipe are fixed by the clamping support mechanism, and the spinning wheel mechanism spins the steel pipe; the rotating mechanism is a hydraulic rotating device, the chuck is arranged in the middle of the hydraulic rotating device, and the steel pipe is driven to rotate by the hydraulic rotating device, the clamping support mechanism comprises a hydraulic cylinder, a tailstock and a mold inner core rod, the tailstock is arranged between the hydraulic cylinder and the mold inner core rod, the mold inner core rod on the tailstock is driven by the hydraulic cylinder to make horizontal axial movement, and the mold inner core rod is extended into or extend the steel pipe; the spinning wheel mechanism includes a fixed frame, a movable rod, a spinning wheel and a hydraulic device, one end of the movable rod is arranged on the inner side of the top of the fixed frame, the spinning wheel is arranged on the other end of the movable rod, the hydraulic device is arranged on the top of the fixed frame, and the hydraulic device is connected to the movable rod, and the spinning wheel on the movable rod is driven by the hydraulic device to extrude the steel pipe, and a nozzle is provided on the side of the movable rod; the spinning wheel mechanism also includes a guide rail, a ball screw, a support seat and a servo motor, the guide rail is arranged on the base, and the guide rail is connected to the fixed frame, the support seat and the servo motor are arranged at both ends of the ball screw, the ball screw is arranged on the side of the guide rail, the ball screw penetrates into the fixed frame, and the ball screw is driven by the servo motor to drive the fixed frame to move horizontally axially, a ball nut is provided in the fixed frame, the ball screw penetrates into the ball nut, and the fixed frame is driven to move by the movement of the ball nut; The following steps are involved: Step 1: Place the steel pipe in the rotary mechanism of the double-head spinning machine, adjust the position of the steel pipe, and close the chuck to lock the middle of the steel pipe; Step 2: Control the spinning wheel mechanism to quickly shift to both sides of the steel pipe clamping position; Step 3: The clamping support mechanism fixes both ends of the steel pipe, and the core rod in the mold is inserted into the steel pipe with the help of the hydraulic cylinder; Step 4: The rotary mechanism drives the steel pipe to start rotating, and the core rod in the mold rotates passively under the drive of the steel pipe; Step 5: Extend the movable rod and the spinning wheel at a uniform speed to the set extrusion position, and extrude the outer diameter of the steel pipe in three directions on both sides simultaneously. At the same time, the nozzle is opened and coolant is started to be filled into the spinning wheel. Step 6: The servo motor starts to drive the double-sided ball screw to rotate counterclockwise at a uniform speed. Under the rotation of the double-sided ball screw, the double-sided ball nut, together with the spinning wheel mechanism, begins to perform a double-sided outward uniform axial reduction and wall thickness feeding action on the outer diameter of the steel pipe; Step 7: The CNC system controls the movable rod and the spinning wheel to retract to the starting position, and the fixed frame also quickly moves to the starting position; Step 8: The rotation of the rotary mechanism stops, and the bilateral hydraulic cylinders uniformly pull the core rods in the bilateral mold out from the inside of both ends of the steel pipe and return them to the starting position.

2. The steel pipe wall reduction method according to claim 1, characterized in that: In step 2, the servo motor is controlled by the numerical control system to start driving the bilateral ball screw to rotate rapidly clockwise. The fixed frame shifts when the ball screw and the servo motor provide power, and at the same time, the spinning wheel on the movable rod can move to the top of the steel pipe.

3. The steel pipe wall reduction method according to claim 1, characterized in that: In step 7, under the control of the CNC system, the hydraulic device controls the movable rod and the spinning wheel to retract, and the bilateral servo motors drive the bilateral ball screws to rotate rapidly counterclockwise. Under the rotation of the bilateral ball screws, the bilateral ball nuts and the spinning wheel mechanism move rapidly axially to the starting position.

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