A new type of numerical control precision double-spindle turning and boring machine

Abstract

The utility model discloses a novel numerical control precision double-spindle turning and boring machine, the whole machine is located on a large precision flat plate, the middle of the flat plate is the position of clamping workpiece, has several "T" grooves, wherein the central "T" groove is the longitudinal reference of the machine tool, and the both ends of the flat plate are two sets of mutually parallel and equal-height precision guide rails, two same longitudinal slides are respectively arranged on the two sets of longitudinal guide rails, the longitudinal slides are respectively provided with left and right spindle boxes, the spindle box bodies are supported on three sets of precision rolling bearings, the short cylindrical step at the front end of the spindle is the positioning cylinder of the flat rotary disc main disc, the flat rotary disc main disc is rigidly connected with the spindle end face and rotates synchronously, the radial disc moves radially along the radial guide rail on the main disc, and an automatic balancing device is designed between the flat rotary disc main disc and the radial disc. The utility model has high machining precision and is convenient to use.

Description

Technical Field

[0001] This utility model relates to a CNC precision twin-spindle boring machine. Background Technology

[0002] Large bearing housings are key components of high-power wind turbines, with a maximum bearing bore size of approximately φ4000 and an axial distance of over 4300mm between the two bearings. To improve generator efficiency, the machining requirements for the main bearing housing are extremely high. For example, the coaxiality of the bearing bores at both ends is φ0.05, and the perpendicularity of the bearing bore end face to the centerline is 0.08. Such high form and position tolerances are equivalent to grade 5 precision used specifically for high-precision shafts (bore) components. If machining is performed using a general-purpose horizontal precision boring machine, an extended, high-rigidity precision boring bar is typically required. This process is inefficient, and due to issues with the boring bar's precision and rigidity, the machining accuracy is highly unstable. Utility Model Content

[0003] The purpose of this invention is to provide a high-precision CNC twin-spindle boring machine.

[0004] The technical solution of this utility model is: A novel CNC precision dual-spindle turning and boring machine is characterized by: the entire machine being mounted on a large precision plate, with the workpiece clamping position in the middle of the plate, which has several "T" shaped grooves, one of which serves as the longitudinal reference of the machine tool; two sets of parallel and equally high precision guide rails at both ends of the plate, with the machining and installation of these two sets of guide rails based on the reference "T" shaped groove of the middle plate; two identical longitudinal slide plates are respectively configured on the two sets of longitudinal guide rails; a servo motor on each side drives the left and right longitudinal slide plates respectively via precision ball screws; left and right spindle boxes are respectively mounted on the longitudinal slide plates, with the internal structures of the two spindle boxes being completely identical; and flat turntables at the ends of the two spindles, but with different dimensions. The spindle housing spindle is supported on three sets of precision rolling bearings; The short cylindrical step at the front end of the spindle serves as the positioning cylinder for the main plate of the rotary disc. The main plate of the rotary disc is rigidly connected to the end face of the spindle and rotates synchronously. The radial disc moves radially along the radial guide rail on the main plate. An automatic balancing device is designed between the main plate of the rotary disc and the radial disc.

[0005] The main spindle housing is supported by three sets of precision rolling bearings; the front bearing is a double-row short cylindrical roller bearing with a 1:12 taper on the inner ring, which is locked by a nut and the bearing clearance is adjusted; the middle pair of tapered roller bearings are used to bear the axial force acting on the main spindle, eliminate axial clearance, and improve the bending stiffness of the main spindle; a set of deep groove ball bearings is configured at the rear end of the main spindle to improve the rotational accuracy of the main spindle; a cylindrical helical gear is provided in the middle of the main spindle to mesh with the pinion on the input shaft.

[0006] The automatic balancing device is a gear and rack mechanism that can move eccentrically. When the tool needs to move radially, the racks on both sides of the radial disk drive the gears to rotate, moving two sets of additional masses in opposite directions to ensure the balance of the mass of the flat rotating disk. An electro-permanent magnet mechanism is provided on the bottom surface of the balancing block.

[0007] The spindle is hollow, and the radial servo motor cable, the balancing permanent magnet cable, and the cooling water pipe are introduced from the front end of the spindle and pass through the slip ring at the tail end. These cables and water pipes remain relatively stationary with the spindle in the spindle hole, and after exiting the slip ring, they are connected to the control unit through the corresponding rotary outlet.

[0008] It is equipped with an underground buried cooling and chip removal system, while the processing work area is above ground.

[0009] This invention features high processing precision and ease of use. Attached Figure Description

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0011] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0012] Figure 2 This is a schematic diagram of the spindle box structure.

[0013] Figure 3 This is a schematic diagram of the flat rotating disk assembly structure.

[0014] Figure 4 This is a schematic diagram of a cooling chip removal system. Detailed Implementation

[0015] A novel CNC precision dual-spindle turning and boring machine is mounted on a large precision plate (i.e., the bed 1). The plate has several T-slots in the middle for clamping the workpiece, with the central T-slot serving as the machine tool's longitudinal reference. At both ends of the plate are two sets of parallel, equally high precision guideways 2a and 2b. The machining and installation of these guideways are based on the central T-slot of the plate. Two identical longitudinal slide plates 3a and 3b are respectively mounted on the two sets of longitudinal guideways. A servo motor on each side drives the left and right longitudinal slide plates 3a and 3b via precision ball screws 4a and 4b, respectively. Left and right spindle boxes 5a and 5b are mounted on the longitudinal slide plates, respectively. The internal structures of the two spindle boxes are identical. The flat turntables 6a and 6b at the ends of the two spindles have the same structure but different dimensions to match the dimensions of the bearing holes being machined.

[0016] The spindle housing 2-1 is made of HT300 casting, with a cover 2-2 on top. The spindle 2-3 is supported by three sets of precision rolling bearings. The front bearing is a double-row short cylindrical roller bearing 2-4 with a 1:12 taper on the inner ring. The inner ring is locked by a nut 2-5, and the bearing clearance is adjusted. A pair of tapered roller bearings 2-6 in the middle are used to withstand the axial force acting on the spindle, eliminate axial clearance, and improve the bending stiffness of the spindle. A set (2-3) of deep groove ball bearings 2-7 are arranged at the rear end of the spindle to improve the rotational accuracy of the spindle. A cylindrical helical gear 2-8 is installed at an appropriate position in the middle of the spindle to mesh with a pinion 2-9 on the input shaft. The gear ratio of this pair of gears is about 1:2.5. The servo spindle motors 10a and 10b drive the spindle 2-3 to perform cutting rotation motion via a high-power reducer 7a and 7b, and then via the pinion 2-9 on the input shaft.

[0017] The short cylindrical step at the front end of the spindle serves as the positioning cylinder for the main plates 6a and 6b of the rotary table. The main plates are rigidly connected to the spindle end face and rotate synchronously. The radial plates 8a and 8b move radially along the radial guide rails 3-5 on the main plates. The radial servo motor 3-6 drives the radial plate 3-2 via a ball screw to determine the position of the boring tool and ensure the boring hole size and the surface roughness of the machined surface. To ensure machining accuracy, the radial servo motor 3-6 of this machine adopts a power-off self-locking type. During machining, due to changes in the machining diameter, the tool and the radial plates must move radially. This will cause a radial mass offset of the rotary table, resulting in eccentric vibration when the rotary table rotates at high speed. To effectively reduce eccentric vibration, an automatic balancing device is designed between the main plate and the radial plates. This device is a gear and rack mechanism that can move eccentrically. When the tool needs to move radially, the racks 3-7 on both sides of the radial plates drive the gears to rotate 3-4, moving the two sets of additional masses in opposite directions to ensure the balance of the rotary table mass. An electro-permanent magnet mechanism is provided on the bottom surface of the balance block 3-3. When the machine tool tool moves radially, the electro-permanent magnet block is first de-energized and demagnetized, causing the balance block to move accordingly. When the tool moves into position (e.g., during boring), the electro-permanent magnet is automatically energized to maintain the position of the balance block and eliminate backlash vibration. When the machine tool is cutting the end face, the electro-permanent magnet mechanism is de-energized and demagnetized, and the balance block moves accordingly for balance.

[0018] The spindle 2-3 is hollow, allowing the radial servo motor cable, balancing permanent magnet cable, and cooling water pipes, all located in the rotary table, to be guided from the front end of the spindle and passed through the slip rings 9a and 9b at the rear. These cables and water pipes remain relatively stationary within the spindle bore and connect to the control components via corresponding rotary outlets after exiting the slip rings. The inner bore at the front end of the spindle is a standard 1:20 tapered hole 2-10, used as a reference for precisely adjusting the concentricity of the two spindles.

[0019] The spindle drive motors 10a and 10b are servo spindle motors, which are directly connected to the input shaft of the spindle box 2-11 via reducers 7a and 7b with a speed ratio of more than 20 times.

[0020] During operation, the cutting part of the tool needs sufficient cooling, and a large amount of chips need to be automatically removed. Therefore, an underground buried cooling and chip removal system was designed. The entire machining area is above ground level 4-5, while the area below ground level is a leak-proof, seepage-proof chip removal, filtration, water storage, and water delivery system made of reinforced concrete. A large-capacity cooling water tank 4-3 is located at the right end. A large-capacity, high-lift water pump 4-4 is installed in the middle of the tank. The high-pressure cooling water pumped by the pump is distributed through two independently controlled pipes via high-pressure water pipe 4-6 to the input ends of the slip rings 9a and 9b at the tail ends of the two spindle boxes. Finally, the cooling water is guided to the cutting point through the output end of the slip rings and a soft water pipe that remains relatively stationary with respect to the spindle inner bore 2-10. To ensure that the cooling water pumped by the cooling pump 4-4 is free of chips, the cooling water tank 4-3 is divided into three sections, with automatic flow of cooling water containing a small amount of chips at both ends. Fine-mesh filter plates are installed at each one-third of the way down the cooling water tank 4-3. The return water containing a small amount of chips flows into both ends of the cooling water pool on its own. It undergoes initial sedimentation at both ends of the cooling water pool and finally enters the middle part of the cooling pool where the high-pressure pump is located after passing through the filter screens on both sides of the water pump. The high-pressure pump then delivers the water to the cutting position, thus realizing the automatic circulation of cooling water.

[0021] The chips generated during machining, along with the cooling water, enter the chip removal system via the worktable under gravity. The chips are then conveyed to the left by the spiral chip conveyor 4-2 to the chain-type chip conveyor 4-1, and then lifted by the chain-type chip conveyor to the chip collection box on the floor. The spiral chip conveyor 4-2 is positioned within an inclined arc groove from left to right. During chip removal by the spiral chip conveyor 4-2, the cooling water automatically separates and flows to the right along the inclined arc groove into the cooling water pool 4-3 at the right end. This automatically achieves water-chip separation.

Claims

1. A novel CNC precision twin-spindle turning and boring machine, characterized by: The entire machine is mounted on a large precision plate. The center of the plate is where the workpiece is clamped, and it has several "T" shaped grooves. The central "T" shaped groove serves as the longitudinal reference of the machine tool. At both ends of the plate are two sets of parallel and equally high precision guide rails. The machining and installation of these two sets of guide rails are based on the reference "T" shaped groove of the central plate. Two identical longitudinal slide plates are respectively mounted on the two sets of longitudinal guide rails. There is a servo motor on each side, which drives the left and right longitudinal slide plates respectively via precision ball screws. The left and right spindle boxes are mounted on the longitudinal slide plates. The internal structure of the two spindle boxes is exactly the same. The flat turntables at the ends of the two spindles are different in size. The spindle housing spindle is supported on three sets of precision rolling bearings; The short cylindrical step at the front end of the spindle serves as the positioning cylinder for the main plate of the rotary disc. The main plate of the rotary disc is rigidly connected to the end face of the spindle and rotates synchronously. The radial disc moves radially along the radial guide rail on the main plate. An automatic balancing device is designed between the main plate of the rotary disc and the radial disc.

2. The novel CNC precision twin-spindle turning and boring machine according to claim 1, characterized in that: The main spindle housing is supported by three sets of precision rolling bearings; the front bearing is a double-row short cylindrical roller bearing with a 1:12 taper on the inner ring, which is locked by a nut and the bearing clearance is adjusted; the middle pair of tapered roller bearings are used to bear the axial force acting on the main spindle, eliminate axial clearance, and improve the bending stiffness of the main spindle; a set of deep groove ball bearings is configured at the rear end of the main spindle to improve the rotational accuracy of the main spindle; a cylindrical helical gear is provided in the middle of the main spindle to mesh with the pinion on the input shaft.

3. A novel CNC precision twin-spindle turning and boring machine according to claim 1, characterized in that: The automatic balancing device is a gear and rack mechanism that can move eccentrically. When the tool needs to move radially, the racks on both sides of the radial disk drive the gears to rotate, moving two sets of additional masses in opposite directions to ensure the balance of the mass of the flat rotating disk. An electro-permanent magnet mechanism is provided on the bottom surface of the balancing block.

4. A novel CNC precision twin-spindle turning and boring machine according to claim 1, characterized in that: The spindle is hollow, and the radial servo motor cable, the balancing permanent magnet cable, and the cooling water pipe are introduced from the front end of the spindle and pass through the slip ring at the tail end. These cables and water pipes remain relatively stationary with the spindle in the spindle hole, and after exiting the slip ring, they are connected to the control unit through the corresponding rotary outlet.

5. A novel CNC precision twin-spindle turning and boring machine according to claim 1, characterized in that: It is equipped with an underground buried cooling and chip removal system, while the processing work area is above ground.

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