Lead screw transmission supporting system capable of restraining deformation and control method

Abstract

The invention belongs to the field of precision control of lead screw transmission systems of numerical control machine tools, and discloses a lead screw transmission supporting system capable of restraining deformation and a control method. A lead screw transmission supporting system capable of restraining deformation comprises a lathe bed, a lead screw left fixing support, a sliding table, a rotating nut, a lead screw right fixing support, a long lead screw, a guide rail supporting system and a lead screw transmission supporting unit. In the lead screw transmission supporting system, auxiliary support is provided for the long lead screw and used for resisting gravity bending deformation, the transmission precision of the lead screw transmission supporting system is improved, and the bad states of noise and vibration in the system are improved. According to the lead screw transmission supporting system, the use effect of a long lead screw scheme in an ultra-long numerical control machine tool is facilitated, and a new supporting scheme is provided for a lead screw transmission system of a large machine tool.

Description

Technical Field

[0001] The invention belongs to the field of precision control of a screw transmission system of a numerically controlled machine tool, and relates to a screw transmission support system capable of suppressing deformation and a control method. Background Art

[0002] In recent years, with the domestic production of core components for products in industries like aerospace and shipbuilding, demand for large machine tools has steadily increased. Combined with the demand for machining various ultra-long structural components, high-precision CNC machine tools with ultra-long strokes have become a critical component of industrial production. The screw drive system is one of the most critical components for achieving ultra-long strokes in CNC machine tools. Its ability to control precision, temperature, and noise levels determines the overall performance of the machine tool. For small and medium-sized machine tools, screw drive systems are typically smaller in size and length, and weight-induced screw deformation is often controlled by pre-tensioning. However, screw drive systems in large machine tools typically utilize large, extra-long nuts with large diameters and wide support spans to rotate the screws, meeting the long stroke requirements of linear axes. In these drive systems, the ultra-long screws are stationary and rotated by the drive nut. One of the key technical issues affecting the accuracy of ultra-long screws is the self-weight bending deformation of the screw drive system. Severe bending can lead to poor kinematic errors and poor precision stability of the moving parts driven by the screw, further impacting noise, temperature rise, and screw life. Therefore, suppressing the deformation of the long screw transmission system and adopting appropriate control methods are necessary conditions to ensure the motion accuracy and stability of large machine tools.

[0003] Currently, a common method for controlling lead screw deformation under its own weight is a follower-type auxiliary support. This support mechanism is mounted on the moving component and moves with the slide. For example, as described in the paper "High-Precision Lead Screw Support Device for Ensuring High and Rapid Traverse Speeds of the Feed Axis" published by Yu Peng of Shenyang Zhongjie Machine Tool Co., Ltd., the lead screw rotates, driving the nut, which in turn drives the slide to move horizontally along the lead screw axis. This movement impacts with bumpers on both sides of the inner wall of the lead screw support seat, thereby driving the lead screw support device, excluding the guide rail, to move horizontally, achieving dynamic support for the lead screw. This type of lead screw support solution is somewhat effective for short to medium-length lead screws and is used in a screw rotation drive scheme. However, it can only provide partial support for very long lead screws and is ineffective in supporting deformation throughout the entire stroke.

[0004] The present invention combines the application characteristics and machine tool technology requirements to propose a screw transmission support system and control method that can suppress deformation, thereby ensuring the accuracy, reliability and stability of the precision transmission of the screw of large machine tools. Summary of the Invention

[0005] In order to solve the above problems in the prior art, the present invention provides a screw transmission support system and a control method capable of suppressing deformation. The support system includes two support units. Figure 1Support No. 1 and Support No. 2 in the machine serve as auxiliary supports for the screw during linear motion. The effective control of the support system by the CNC system and the hydraulic station reduces the bending deformation caused by the weight of the screw.

[0006] The technical solution of the present invention:

[0007] A screw transmission support system capable of suppressing deformation includes a bed 1, a screw left fixed support 2, a slide 5, a rotating nut 6, a screw right fixed support 7, a long screw 8, a guide rail support system 9, and a screw transmission support unit;

[0008] The upper surface of the bed 1 is a guide rail mounting surface, on which a guide rail support system 9 is installed, and multiple slides 5 are installed on the guide rail support system 9; a long screw 8 passes through the multiple slides 5 in sequence, and its two ends are fixed to the bed 1 by the left screw fixed support 2 and the right screw fixed support 7 respectively; a rotating nut 6 is installed between the slide 5 and the long screw 8, and the rotating nut 6 is driven by a motor to make the slide 5 move along the guide rail direction;

[0009] A screw transmission support unit is provided below the long screw 8 .

[0010] The screw transmission support unit includes a screw support nylon block 10, a telescopic rod 11, a linear bearing 12, a support cylinder 13, a hydraulic lever 14, a position sensor 15 and a position detection rod 16;

[0011] The extension rod of the hydraulic lever 14 is connected to one end of the telescopic rod 11, and the other end of the telescopic rod 11 is connected to the screw supporting nylon block 10; the telescopic rod 11 and the supporting cylinder body 13 are positioned through a linear bearing 12; the position detection rod 16 is connected to the telescopic rod 11 through the supporting cylinder body 13, and the telescopic movement is synchronized; two position sensors 15 are configured on the hydraulic lever 14 for detecting its extended and retracted positions.

[0012] The hydraulic lever 14 is a reversible oil cylinder with one in and one out. The hydraulic lever 14 is connected to the oil supply system, the oil supply system is connected to the hydraulic station, and the hydraulic station control is connected to the machine tool CNC system. The control of the telescopic rod 11 is achieved by setting the corresponding program.

[0013] A screw transmission support system capable of suppressing deformation is used in a method for suppressing screw deformation control, and the steps are as follows:

[0014] According to the positional relationship among the slide 5, the bed 1 and the screw transmission support unit, the oil supply amount, oil supply speed and reversing of the oil supply chamber of the hydraulic lever 14 in the screw transmission support unit are controlled to realize the extension and retraction control of the telescopic rod 11, and further realize the application of a gravity reverse force to the long screw 8 at the set position to resist deformation due to gravity, thereby achieving the purpose of reducing the amount of gravity deformation and providing a safe and reliable method for suppressing deformation.

[0015] The present invention provides auxiliary support for the lead screw in a screw drive support system, resisting bending deformation due to gravity, improving the transmission accuracy of the transmission system, and alleviating adverse noise and vibration conditions within the system. The lead screw drive support system of the present invention facilitates the use of long lead screws in ultra-long CNC machine tools and provides a new support solution for lead screw drive systems in large machine tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the layout diagram of the screw drive support system.

[0017] Figure 2 This is the structural diagram of the screw transmission support unit.

[0018] Figure 3 This is a diagram illustrating the control method of the screw drive support system.

[0019] In the figure: 1-bed; 2-left fixed support of the screw; 3-first screw transmission support unit; 4-second screw transmission support unit; 5-slide; 6-rotating nut; 7-right fixed support of the screw; 8-long screw; 9-guide rail support system; 10-screw support nylon block; 11-telescopic rod; 12-linear bearing; 13-support cylinder; 14-hydraulic lever; 15-position sensor; 16-position detection rod. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and technical solutions.

[0021] The present invention provides a screw transmission support system and a control method capable of suppressing deformation. The arrangement diagram of the screw transmission support system in the screw transmission application is as follows: Figure 1 As shown, the structural diagram of the screw transmission support unit is as follows Figure 2 As shown, the control method of the screw drive support system is as follows Figure 3 The screw drive support system provides auxiliary support for the screw during movement, suppresses the screw's gravity bending deformation, and improves the movement accuracy, stability, and noise performance of the moving parts.

[0022] A screw drive support system capable of suppressing deformation, in which a screw drive support unit is arranged. The screw drive system to which the present invention is applicable is characterized by an ultra-long stroke screw, usually more than three meters. The two ends of the long screw 8 are fixedly mounted to the machine tool bed 1 by screws through the screw left fixed support 2 and the screw right fixed support 7. The long screw 8 is matched with a rotating nut 6 which is installed in the slide 5 by flange screws. The rotating nut 6 is driven by a motor to rotate, thereby realizing the movement of the slide 5. Since the size of the long screw 8 is too long, a bending deformation will be formed due to the action of gravity after the two ends are fixedly supported, resulting in poor accuracy of the long screw 8 after installation. Different numbers of screw drive support units are set according to the different lengths of the long screw 8. The present invention is applied to a five-meter-long screw 8 in actual products. Two supports, a first screw drive support unit 3 and a second screw drive support unit 4, are set under the long screw 8. The two screw drive support units have the same structure. It is installed on the bed 1 by screws, and the screw drive support unit is connected to the machine tool hydraulic station. The hydraulic station and the solenoid valve are controlled by the CNC system to achieve the motion control of the screw drive support unit.

[0023] The assembly relationship of the screw drive support unit is as follows:

[0024] The extension rod of the hydraulic lever 14 is connected to one end of the telescopic rod 11 through a screw thread, and the other end of the telescopic rod 11 is connected to the screw support nylon block 10 through a screw. The above composition forms a piston rod that can realize telescopic action. The support cylinder 13 fixes the screw transmission support unit to the bed 1 through screws to provide support force for the screw transmission support unit. The linear bearing 12 is embedded in the support cylinder 13 to support and position the telescopic rod 11. The position detection rod 16 is connected to the telescopic rod 11 as a whole and performs telescopic actions synchronously. The hydraulic lever 14 has two stroke chambers, an extension oil supply chamber and a retraction oil supply chamber, both of which are connected to the solenoid valve and the hydraulic station through hydraulic pipes. Two position sensors 15 are installed on the outer wall of the hydraulic lever 14. When the position detection rod 16 performs the extension and retraction actions, the position sensor 15 outputs the extreme position signals of the two actions.

[0025] The control method for suppressing deformation of the screw drive support system is as follows:

[0026] like Figure 1 and 3, the slide 5 needs to be driven by the long screw 8 to perform linear reciprocating motion, that is, from position A to position C, and then from position C to position A, and the installation positions of the two screw drive support units are within the travel range. When the slide 5 moves from position A to position C and is at position A, the first screw drive support unit 3 retracts and the second screw drive support unit 4 extends; when the slide 5 passes the first screw drive support unit 3 and reaches position a1, the first screw drive support unit 3 extends, and at this time, both screw drive support units are in the extended state; when the slide 5 reaches position a2, the second screw drive support unit 4 retracts, and at this time, the first screw drive support unit 3 still remains in the extended state; when the slide 5 passes the position of the second screw drive support unit 4, the two screw drive support units still maintain the position of the first screw drive support unit 3 The two screw drive support units remain in this state; when the slide 5 reaches the C position, the two screw drive support units remain unchanged; when the slide 5 starts to move in the opposite direction from the C position to the A position, when the slide 5 passes the second screw drive support unit 4 in the reverse direction, the two screw drive support units remain in this state; when the slide 5 reaches the a4 position, the second screw drive support unit 4 extends; when the slide 5 reaches the a3 position, the first screw drive support unit 3 retracts, and the two screw drive support units maintain this state until the slide 5 reaches the A position, and then starts to repeat the above cycle.

[0027] This invention utilizes a novel lead screw support structure, combined with a specific motion control method, to counteract gravity-induced bending deformation of an extremely long lead screw, thereby ensuring assembly accuracy in the free-running state. This method improves the lead screw's transmission accuracy and stiffness, and improves dynamic performance, such as vibration and temperature rise. Application of this invention to ultra-large CNC turning and milling machine tools can further address the high-precision performance requirements of lead screw drives.

Claims

1. A screw drive support system capable of suppressing deformation, characterized in that: The screw drive support system comprises a bed (1), a screw left fixed support (2), a slide (5), a rotating nut (6), a screw right fixed support (7), a long screw (8), a guide rail support system (9) and a screw drive support unit; The upper surface of the bed (1) is a guide rail mounting surface, on which a guide rail support system (9) is mounted, and a plurality of slides (5) are mounted on the guide rail support system (9); a long lead screw (8) passes through the plurality of slides (5) in sequence, and its two ends are fixed to the bed (1) by a lead screw left fixed support (2) and a lead screw right fixed support (7), respectively; a rotating nut (6) is mounted between the slide (5) and the long lead screw (8), and the rotating nut (6) is driven by a motor to make the slide (5) move in the direction of the guide rail; A screw transmission support unit is provided below the long screw (8).

2. The screw drive support system according to claim 1, characterized in that: The screw transmission support unit comprises a screw support nylon block (10), a telescopic rod (11), a linear bearing (12), a support cylinder (13), a hydraulic lever (14), a position sensor (15) and a position detection rod (16); The extension rod of the hydraulic lever (14) is connected to one end of the telescopic rod (11), and the other end of the telescopic rod (11) is connected to the screw support nylon block (10); the telescopic rod (11) and the supporting cylinder (13) are positioned by a linear bearing (12); the position detection rod (16) is connected to the telescopic rod (11) through the supporting cylinder (13) and performs synchronous telescopic movement; two position sensors (15) are configured on the hydraulic lever (14) for detecting the extension and retraction positions thereof.

3. The screw drive support system according to claim 2, characterized in that: The hydraulic lever (14) is a one-in, one-out reversible oil cylinder. The hydraulic lever (14) is connected to the oil supply system, the oil supply system is connected to the hydraulic station, and the hydraulic station control is connected to the machine tool CNC system. The telescopic rod (11) is controlled by setting a corresponding program.

4. A method for controlling the deformation of a screw drive support system capable of suppressing deformation, characterized in that: Here are the steps: According to the positional relationship among the slide (5), the bed (1) and the screw transmission support unit, the oil supply amount, oil supply speed and reversal of the oil supply chamber of the hydraulic lever (14) in the screw transmission support unit are controlled to realize the extension and retraction control of the telescopic rod (11), and further realize the application of a gravity reverse force to the long screw (8) at the set position to resist the deformation due to gravity, realize the purpose of reducing the gravity deformation, and provide a safe and reliable method for suppressing deformation.

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