Workpiece overturning and re-clamping system of single-spindle turn-milling center

Abstract

The single-spindle turn-milling center has the advantages of simple structure, small size and low cost, but has the defect that only one end of a workpiece can be machined. The workpiece overturning and re-clamping system for the single-spindle turn-milling center is designed for the single-spindle turn-milling center, comprises a workpiece overturning mechanism, a material ejecting mechanism and a precision measuring device, and is mounted at a proper part of the single-spindle turn-milling center, so that a workpiece of which one end is machined by the single-spindle turn-milling center is overturned by 180 degrees, and the workpiece is clamped by the workpiece overturning mechanism. And the deviation is measured and corrected, clamping is carried out again, the clamping precision and rigidity are guaranteed, machining of the second end of the workpiece is further completed, and the use value of the single-spindle turn-milling center is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal cutting machine tool accessory equipment, in particular to a special matching mechanism for a single-spindle turning and milling center. Background Art

[0002] Existing milling centers are equipped with two workpiece spindles to complete the entire processing of both ends of a complex workpiece, but the milling center equipped with two workpiece spindles has a complex structure, high cost, and large size. The single-spindle milling center has the advantages of simple structure, low cost, and small size, but the disadvantage is that it cannot complete the entire processing of both ends of the workpiece in one clamping.

[0003] Patent 93104213.5 discloses a single-spindle machining center, which can also only complete the machining of one end of a workpiece. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcoming that the existing single-spindle turning and milling center cannot complete all the processing of both ends of the workpiece. In order to achieve the above purpose, the present invention designs the following technical solutions:

[0005] The workpiece flipping and re-clamping system of the single-spindle turning and milling center includes a workpiece flipping mechanism, a material ejecting mechanism, and a precision measuring device, which are installed at the appropriate position of the single-spindle turning and milling center to flip the workpiece that has been processed on one end 180 degrees, measure and correct the deviation, re-clamp, and ensure the accuracy and rigidity of the clamping to further complete the processing of the second end.

[0006] The above-mentioned workpiece flipping mechanism includes a pliers body, a large gear, a small gear, a shaft, a rack, a large jaw, a small jaw, a short rack, a push rod, a piston rod, a piston, an external screw sleeve, an adjusting nut, a cylinder barrel, a front cylinder head, a rear cylinder head, a flip shaft, a front bearing, a rear bearing, a flip seat, a torsion spring, a worm gear, a servo motor A, a worm, a bearing seat, and an angular contact bearing. The flip shaft is installed in the flip seat through front and rear bearings, the turbine is coaxially fixed with the flip shaft, the front end of the flip shaft is coaxially fixed with the pliers body, the rear end of the flip shaft is coaxially fixed with the front cylinder head, the worm is coaxially fixed with the servo motor A, and is installed in the flip seat through bearings and bearing seats, the large gear and the small gear are coaxially fixed and have bearings installed inside , can rotate on the shaft, the large gear meshes with the rack, the small gear meshes with the short rack, the small jaw is fixedly installed with the short rack, the large jaw is fixedly installed with the rack, the push rod connects the piston rod and the small jaw, when the piston is pushed forward, the two large gears will pass through the two racks to pull the large jaw back in the opposite direction, when the internal angle of the large jaw is 60 degrees, the ratio of the pitch diameter of the large and small gears is 2:1, it can self-center and clamp cylindrical workpieces with a certain diameter range, the piston rod, piston, cylinder barrel, front cylinder head, and rear cylinder head form a cylinder, or oil cylinder, the adjusting nut is used to adjust the axial position of the push rod, the outer screw sleeve is used to accommodate and fix the adjusting nut, and the torsion spring is used to apply a unidirectional torque to the flip shaft to eliminate the gap and improve the rotation accuracy.

[0007] In the simplest case, the workpiece turning mechanism can be installed on the side of the turning and milling center directly or via two horizontal guide rails and an advance and retreat cylinder.

[0008] Considering that the upper surface of some workpieces is not allowed to contact the chuck surface or the jaw positioning surface when they are clamped for the second time, in this case, in order to ensure the clamping accuracy, the horizontality of the upper surface of the flipped workpiece must be detected and adjusted. For this purpose, the workpiece flipping structure should be installed on a fine-tuning mechanism that can adjust the horizontality of the workpiece around two orthogonal axes. Since the workpiece flipping mechanism can be used as a horizontal fine-tuning of an axis, only a horizontal fine-tuning mechanism perpendicular to the flipping axis is required. The horizontal fine-tuning mechanism perpendicular to the flipping axis includes an upward tilt seat, a bearing, a downward tilt seat, a motor seat, a servo motor, a coupling, a ball screw, a ball nut, a nut seat, a bearing, a roller shaft, a spring, and an adjusting screw. Thread, micro guide rail, micro guide rail slider, the upward tilt seat is installed on the downward tilt seat through two bearings, the motor seat is installed on the downward tilt seat, the upper end of the motor seat is installed with a ball screw through a pair of bearings, the lower short is installed with a servo motor, the servo motor is connected to the ball screw through a coupling, the ball nut is installed in the nut seat, the nut seat is installed on the slider of the micro guide rail, and can be pushed up and down by the ball screw, there are roller grooves on both sides of the nut seat, there are bearings in the grooves, the bearings are installed on the upward tilt seat by the roller shaft, a spring is installed between the upward tilt seat and the downward tilt seat to eliminate the gap and improve the accuracy of angle fine-tuning, the screw is used to adjust the spring preload force, and controlling the servo motor B can achieve precise fine-tuning of the inclination angle of the upward tilt seat.

[0009] When the workpiece is flipped 180 degrees and the machined surface faces the chuck, if the machined surface of the workpiece is not allowed to contact the chuck surface or the jaw positioning surface, it is necessary to use the precision measuring device on the spindle box to detect the height of the four points on the front, back, left and right of the workpiece surface, and control the servo motor B to make fine adjustments according to the height difference between the front and back points, and control the servo motor A to make fine adjustments according to the height difference between the left and right points, until the horizontality of the workpiece meets the requirements, and then drive the chuck to clamp.

[0010] In order to prevent large stress caused by positioning error during the clamping process and affect the clamping accuracy, the above-mentioned workpiece turning mechanism should also be equipped with a centering error compensation mechanism to limit the stress caused by positioning error to within the range of the preset spring force.

[0011] The centering error compensation mechanism includes left and right guide rails, a cylinder, a triangular seat, upper and lower guide rails, and a spring returner. The spring returner includes two springs, two gaskets, an outer cylinder, a small end cover, a connecting rod, and a large end cover. The downward tilt seat is installed on the triangular seat through the left and right guide rails. At the same time, the downward tilt seat is connected to the triangular seat through the spring returner and two nuts. The nuts are used to adjust the Y-direction position of the clamp. The triangular seat is installed on the side wall of the milling center through the upper and lower guide rails. At the same time, the triangular seat is connected to the push rod of the cylinder through the second spring returner.

[0012] Taking into account that the secondary clamping of some workpieces allows the upper surface to be close to the chuck surface or the jaw positioning surface, a lifting mechanism is also designed to apply a thrust to the workpiece toward the chuck during the chuck clamping process, so that the chuck can be clamped while the machined surface of the workpiece remains close to the chuck plane or the jaw positioning surface, so as to improve the clamping accuracy and rigidity. The ejection mechanism includes: an ejection plate, a ball stud, a swing arm, a swing arm shaft, a bearing, a swing cylinder, a slide, a guide rail, an ejection cylinder, a rear support, a nut, and a screw; the guide rail is installed on the side wall of the single-spindle turning and milling center parallel to the Z axis, the slide is installed on the guide rail, and is pushed up and down by the ejection cylinder to slide, the swing arm is installed on the slide via the swing arm shaft and the bearing, and can be pushed and pulled by the swing cylinder to swing in the horizontal plane, the ejection plate is installed on the ball stud at the end of the swing arm, and when the swing cylinder is pushed out, the ejection plate should be aligned with the bottom of the workpiece, the rear support can swing on the slide, and can be fine-tuned by the screw to adjust the final position of the ejection plate, and after the swing cylinder is pulled back, this mechanism will be in a position that does not interfere with the operation of other mechanisms.

[0013] The precision measuring device can utilize the existing tool measuring device of the turning and milling center, or adopt a laser distance measuring sensor, which is installed on the spindle box of the single-spindle turning and milling center, and the light is irradiated to the upper surface of the turned workpiece.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the main machine adopts a single-spindle turning and milling center structure, which is small in size, simple in structure, and low in cost. At the same time, it adopts a workpiece flipping and re-clamping system, which can realize the processing of the second end of the workpiece while ensuring accuracy, and can greatly improve the use value of the single-spindle turning and milling center. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more specifically and intuitively illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0016] Figure 1 Axonometric view of a single-spindle milling center equipped with a workpiece flipping and re-clamping system;

[0017] Figure 2 It is the axonometric view of the workpiece turning mechanism;

[0018] Figure 3 It is a horizontal cross-sectional view of the workpiece turning mechanism;

[0019] Figure 4 It is a vertical cross-sectional view of the workpiece turning mechanism;

[0020] Figure 5 It is a vertical cross-sectional view of the fine-tuning mechanism perpendicular to the flip axis;

[0021] Figure 6 It is a vertical cross-sectional view of the spring return device;

[0022] Figure 7 This is the axonometric view of the workpiece ejection mechanism;

[0023] Figure 8 It is a vertical cross-sectional view of the workpiece ejection mechanism;

[0024] Fig. 9 Isometric view of the workpiece flipping and re-clamping system for a single-spindle turning and milling center.

[0025] Reference Numbers

[0026] 10 single spindle turning and milling center, 15 spindle box, 16 tool measuring device, 17 laser ranging sensor, 19 ejector mechanism, 20 workpiece turning mechanism, 21 clamp body, 22 large gear, 23 small gear, 24 shaft, 25 rack, 26 large clamp, 27 small clamp, 28 short rack, 29 ejector rod, 30 piston rod, 31 piston, 32 outer screw sleeve, 33 adjusting nut, 34 cylinder barrel, 35 front cylinder head, 36 rear cylinder head, 40 turning shaft, 41 front bearing, 42 rear bearing, 43 turning seat, 44 torsion spring, 45 turbine, 46 servo motor A, 47 worm, 48 bearing seat, 49 bearing, 50 tilt seat, 51 bearing, 52 tilt seat, 53 motor seat, 54 servo motor B, 55 coupling, 56 ball screw, 57 ball nut, 58 nut seat, 59 bearing, 60 roller shaft, 61 spring, 62 adjustment screw, 63 micro guide rail, 64 micro guide rail slider, 65 guide rail, 66 advance and retreat cylinder, 67 triangular seat, 68 guide rail, 69 spring returner, 70 spring, 71 gasket, 72 outer cylinder, 73 small end cover, 74 push rod, 75 nut, 76 large end cover, 81 ejector plate, 82 ball stud, 83 swing arm, 84 swing arm shaft, 85 bearing, 86 slide seat, 87 rear support, 88 screw, 89 nut, 90 swing cylinder, 92 guide rail, 91 ejector cylinder. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0028] Reference Figure 1 The workpiece turning and re-clamping system of the single-spindle turning and milling center includes a workpiece turning mechanism 20, a material ejecting mechanism 19 and a precision measuring device 16 or a laser ranging sensor 17. The workpiece turning mechanism 20 and the material ejecting mechanism 19 are installed outside the side wall of a single-spindle turning and milling center 10 so as to turn the workpiece that has been processed at one end 180 degrees, measure and correct the deviation, or use the material ejecting mechanism to make the upper end face of the workpiece close to the positioning surface of the chuck claw and re-clamp it, so as to continue the processing of the second end of the workpiece.

[0029] Ginseng Figure 2 , Figure 3 , Figure 4The workpiece turning mechanism 20 includes a clamp body 21, a large gear 22, a small gear 23, a shaft 24, a rack 25, a large jaw 26, a small jaw 27, a short rack 28, a push rod 29, a piston rod 30, a piston 31, an outer nut 32, an adjustment nut 33, a cylinder 34, a front cylinder cover 35, a rear cylinder cover 36, a turning shaft 40, a front bearing 41, a rear bearing 42, a turning seat 43, a torsion spring 44, a worm gear 45, and a servo motor A. 46, worm 47, bearing seat 48, angular contact bearing 49, the flip shaft 40 is parallel to the X axis of the turning and milling center, the flip shaft 40 is installed in the flip seat 43 through the front and rear bearings 41, 42, the turbine 45 is fixedly installed with the flip shaft 40, the clamp body 21 is coaxially fixedly installed with the flip shaft 40, the worm 47 is coaxially fixedly installed with the servo motor 46, and is installed in the flip seat 43 through the bearing 49 and the bearing seat 48, the large gear 22 is coaxially fixedly installed with the small gear 23 and has a needle bearing installed inside, which can rotate on the shaft 24, the large gear 22 is meshed with the rack, the small gear 23 is meshed with the short rack 28, the small jaw is fixedly installed with the short rack 28, the large jaw is fixedly installed with the rack 25, and the push rod 29 connects the piston rod 30 with the small Jaw 27, when the piston is pushed forward, the two large gears will pass through the two racks 25 to pull the large jaws back in the opposite direction. When the pitch diameter ratio of the large and small gears is 2:1, the internal angle of the large jaws is 60 degrees, and the cylindrical workpiece within a certain diameter range can be clamped by self-centering, and the center position remains unchanged. Additional jaws are installed on the large and small jaws to clamp smaller workpieces. The piston rod 30, piston 31, cylinder barrel 34, front cylinder cover 35, and rear cylinder cover 36 form a cylinder, or oil cylinder. The adjusting nut 33 is used to adjust the axial position of the push rod 29, and the outer screw sleeve 32 is used to fix the adjusting nut 33 to the rear of the piston rod 30. The torsion spring 44 is used to apply a unidirectional torque to the flip axis to eliminate the gap and improve the rotation accuracy, which is convenient for fine-tuning the horizontality around the flip axis.

[0030] In the simplest case, the workpiece turning mechanism can be installed on the side of the single-spindle turning and milling center directly or via two horizontal guide rails and an advance and retreat cylinder.

[0031] Ginseng Figure 2 and Figure 5, considering that when some workpieces are clamped for the second time, their upper surfaces are not allowed to contact the chuck surface or the claw positioning surface. In this case, in order to ensure the clamping accuracy, the horizontality of the upper surface of the flipped workpiece must be detected and adjusted. For this purpose, a horizontal fine-tuning mechanism perpendicular to the flip axis is designed, and the workpiece flipping mechanism described in Example 2 is installed on the horizontal fine-tuning mechanism perpendicular to the flip axis, which includes an upward tilt seat 50, a bearing 51, a downward tilt seat 52, a motor seat 53, a servo motor B 54, a coupling 55, a ball screw 56, a ball nut 57, a nut seat 58, a bearing 59, a roller shaft 60, a spring 61, an adjusting screw 62, and a micro guide rail 63. The upward tilt seat 50 is installed on the downward tilt seat 52 via two bearings 51, and the motor seat 53 is installed on the downward tilt seat 52. The upper end of the motor seat 53 is installed with a ball screw 56 via a pair of bearings, and the lower short end is installed with a servo motor B 54. The servo motor B 54 is connected to the ball screw 56 through the coupling 55, and the ball nut 57 is installed in the nut seat 58. The nut seat 58 is installed on the slider of the micro guide rail 63 and can be pushed up and down by the ball screw 56. There are roller grooves on both sides of the nut seat 58, and there are bearings 59 in the grooves. The bearings are installed on the upper tilt seat 50 by the roller shaft 60. A spring 61 is installed between the upper tilt seat 50 and the lower tilt seat 52 to eliminate the gap and improve the accuracy of the angle fine-tuning. The screw 63 is used to adjust the spring preload. Controlling the servo motor B 54 can achieve precise fine-tuning of the inclination angle of the upper tilt seat 50.

[0032] When the workpiece is turned 180 degrees and the machined surface faces the chuck, if the machined surface of the workpiece is not allowed to contact the chuck surface or the jaw positioning surface, a precision measuring device is required to detect the height of the four points on the upper surface of the workpiece, and control the servo motor B 54 to make fine adjustments according to the height difference between the front and rear points, and control the servo motor A 46 to make fine adjustments according to the height difference between the left and right points, until the horizontality of the workpiece meets the requirements, and then drive the chuck to clamp.

[0033] Ginseng Figure 2 , Figure 6 In order to prevent stress caused by positioning error during the clamping process and affect the clamping accuracy, the above-mentioned workpiece turning mechanism should also be equipped with a centering error compensation mechanism to limit the stress caused by positioning error within the range of spring force.

[0034] The centering error compensation mechanism includes left and right guide rails 65, cylinder 66, triangular seat 67, upper and lower guide rails 68, and spring return device 69. The spring return device 69 includes two springs 70, two gaskets 71, outer cylinder 72, small end cover 73, connecting rod 74, and large end cover 76. The lower tilt seat 52 is installed on the triangular seat 67 through the left and right guide rails 65. At the same time, the lower tilt seat 52 is connected to the triangular seat 67 through the spring return device 69 and two nuts 75. The nuts 75 are used to adjust the position of the clamp in the Y direction. The triangular seat 67 is installed on the outer wall of the bed through the upper and lower guide rails 68. At the same time, the triangular seat 67 is connected to the push rod of the advance and retreat cylinder 66 through the second spring return device 69. The advance and retreat cylinder 66 is pushed out, the workpiece turning mechanism 20 enters the working position, the advance and retreat cylinder 66 is pulled back, and the entire mechanism is returned to a position that does not interfere with the operation of other mechanisms.

[0035] Ginseng Figure 7 , Figure 8 , Fig. 9 Considering that the secondary clamping of some workpieces allows the upper surface to be close to the chuck surface or the jaw positioning surface, a lifting mechanism is also designed to apply a thrust to the workpiece toward the chuck during the chuck clamping process, so that the machined surface of the workpiece remains close to the chuck plane or the jaw positioning surface while the chuck is clamped, so as to improve the clamping accuracy and rigidity.

[0036] The ejection mechanism includes: an ejection plate 81, a ball stud 82, a swing arm 83, a swing arm shaft 84, a bearing 85, a swing cylinder 90, a slide 86, a guide rail 92, an ejection cylinder 91, a rear support 87, a nut 89, and a screw 88; the guide rail 92 is mounted on the single-spindle turning and milling center bed parallel to the Z axis, the slide 86 is mounted on the guide rail 92, and is pushed and pulled by the ejection cylinder 91 to slide up and down, the swing arm 83 is mounted on the slide 86 via the swing arm shaft 84 and the bearing 85, and can be pushed and pulled by the swing cylinder 90 to swing in the horizontal plane, the ejection plate 81 is mounted on the ball stud 82 at the end of the swing arm 83, when the swing cylinder 90 is pushed out, the ejection plate 81 is aligned with the bottom of the workpiece, the rear support 87 can swing on the slide 86, and can be fine-tuned by the screw 88 to adjust the final position of the ejection plate 81, and after the swing cylinder 90 is pulled back, this mechanism will be in a position that does not interfere with the operation of other mechanisms.

[0037] The precision measuring device can utilize the existing tool measuring device 16 of the turning and milling center, or Fig. 9 A laser distance measuring sensor 17 is used, which is installed on the spindle box 15 of the turning and milling center, and the light is directed to the upper surface of the turned workpiece.

Claims

1. Single spindle turning and milling center workpiece flipping and re-clamping system, characterized by: The single-spindle turning and milling center workpiece turning and re-clamping system comprises a workpiece turning mechanism (20), a material ejecting mechanism (19), and a precision measuring device.

2. The single-spindle turning and milling center workpiece flipping and re-clamping system according to claim 1, characterized in that: The workpiece turning mechanism (20) comprises a pliers body (21), a large gear (22), a small gear (23), a shaft (24), a rack (25), a large jaw (26), a small jaw (27), a short rack (28), a push rod (29), a piston rod (30), a piston (31), an outer screw sleeve (32), an adjusting nut (33), a cylinder barrel (34), a front cylinder cover (35), a rear cylinder cover (36), a turning shaft (40), a front bearing (41), a rear bearing (42), a turning seat (43), a torsion spring (44), a worm wheel (45), a servo motor (46), a worm ( 47), a bearing seat (48), an angular contact bearing (49), the flip shaft (40) is installed in the flip seat (43) via a front bearing (41) and a rear bearing (42), the front end of the flip shaft (40) is fixedly connected to the caliper body (21), the rear end of the flip shaft (40) is coaxially fixedly connected to the front cylinder cover (35), the turbine (45) is fixedly connected to the flip shaft (40), the worm (47) is coaxially fixedly connected to the servo motor (46), and is installed in the flip seat (43) via a bearing (49) and a bearing seat (48), and is meshed with the turbine (45), the large gear The wheel (22) and the pinion (23) are coaxially fixedly connected and have bearings installed therein, and can rotate on the shaft (24); the large gear (22) meshes with the rack (25); the small gear (23) meshes with the short rack (28); the small jaw (27) is fixedly connected with the short rack (28); the large jaw (26) is fixedly connected with the rack (25); the push rod (29) connects the piston rod (30) and the small jaw (27); when the piston is pushed forward, the short rack (28) will drive the two small gears (23); the two large gears will move the large jaw through the two racks (25). (26) reverse pull, when the ratio of the pitch diameter of the large and small gears is 2:1, the inner angle of the large jaw is 60 degrees, and the cylindrical workpiece within a certain diameter range can be clamped by self-centering. The piston rod (30), the piston (31), the cylinder barrel (34), the front cylinder cover (35), and the rear cylinder cover (36) form a cylinder, or an oil cylinder. The adjusting nut (33) is used to adjust the axial position of the push rod (29), the outer screw sleeve (32) is used to accommodate and fix the adjusting nut (33), and the torsion spring (44) is used to apply a unidirectional torque to the tilting shaft to eliminate the gap and improve the rotation accuracy, which is convenient for fine adjustment of the horizontality around the tilting shaft.

3. The single-spindle turning and milling center workpiece flipping and re-clamping system according to claim 2, characterized in that: The turning seat (43) of the workpiece turning mechanism is installed on a horizontal fine-tuning mechanism perpendicular to the turning axis. The fine-tuning mechanism comprises an upward tilting seat (50), a bearing (51), a downward tilting seat (52), a motor seat (53), a servo motor (54), a coupling (55), a ball screw (56), a ball nut (57), a nut seat (58), a bearing (59), a roller shaft (60), a spring (61), an adjusting screw (62), a micro guide rail (63), and a micro guide rail slider (64). The upward tilting seat (50) is installed on the downward tilting seat (52) via two bearings (51), the motor seat (53) is installed on the downward tilting seat (52), and the upper end of the motor seat (53) is installed with a ball screw (56) via a pair of bearings. A servo motor (54) is installed at the lower end. The servo motor (54) is connected to a ball screw (56) via a coupling (55). A ball nut (57) is installed in a nut seat (58). The nut seat (58) is installed on a slider (64) of a micro guide rail (63) and can be pushed up and down by the ball screw (56). Roller grooves are provided on both sides of the nut seat (58). Bearings (59) are provided in the grooves. The bearings are installed on the upper inclination seat (50) by roller shafts (60). A spring (61) is provided between the upper inclination seat (50) and the lower inclination seat (52) to eliminate the gap and improve the accuracy of angle fine-tuning. The screw (63) is used to adjust the spring preload. The control of the servo motor (54) can realize the precise fine-tuning of the inclination angle of the upper inclination seat (50).

4. The single-spindle turning and milling center workpiece flipping and re-clamping system according to claim 2 or 3 is characterized in that: The workpiece turning mechanism is also provided with a centering error compensation mechanism, which includes left and right guide rails (65), a cylinder (66), a triangular seat (67), upper and lower guide rails (68), and a spring returner (69). The spring returner (69) includes two springs (70), two gaskets (71), an outer cylinder (72), a small end cover (73), a connecting rod (74), and a large end cover (76). The downward tilt seat (52) is installed on the triangular seat (67) through the left and right guide rails (65). At the same time, the downward tilt seat (52) is connected to the triangular seat (67) through the spring returner (69) and two nuts (75). The nuts (75) are used to adjust the Y-direction position of the clamp center. The triangular seat (67) is installed on the outer wall of the bed through the upper and lower guide rails (68). At the same time, the triangular seat (67) is connected to the push rod of the advance and retreat cylinder (66) through the second spring returner (69).

5. The single-spindle turning and milling center workpiece flipping and re-clamping system according to claim 1, characterized in that: The ejection mechanism (19) comprises: an ejection plate (81), a ball stud (82), a swing arm (83), a swing arm shaft (84), a bearing (85), a swing cylinder (90), a slide seat (86), a guide rail (92), an ejection cylinder (91), a rear support (87), a nut (89), and a screw (88); the guide rail (92) is installed at an appropriate position of the milling center and is perpendicular to its Z axis, the slide seat (86) is installed on the guide rail (92), and is pushed up and down by the ejection cylinder (91), and the swing arm (83) is moved by the swing arm The shaft (84) and the bearing (85) are mounted on the slide (86) and can be pushed and pulled by the swing cylinder (90) to swing in the horizontal plane. The ejector plate (81) is mounted on the ball stud (82) at the end of the swing arm (83). When the swing cylinder (90) is pushed out, the ejector plate (81) is aligned with the bottom of the workpiece. The rear support (87) can swing on the slide (86) and can be fine-tuned by the screw (88) to adjust the final position of the ejector plate (81). After the swing cylinder (90) is pulled back, the mechanism will be in a position that does not interfere with the operation of other mechanisms.

6. The single-spindle turning and milling center workpiece turning and re-clamping system according to claim 1, characterized in that: The precision measuring device is one of the following: A. A laser distance measuring sensor (17), mounted on the spindle box (15) of the single-spindle turning and milling center (10), emitting light parallel to the Z axis toward the end face of the workpiece; B. An original contact tool measuring head (16) of the single-spindle turning and milling center (10).

Images