Automatic feeding method for inverted turning center

Abstract

The invention belongs to the technical field of machine manufacturing, and particularly provides an inverted turning center automatic feeding method which comprises the steps that a feeding process is executed through a first control system, a blank is conveyed to the front of a feeding and discharging station through a bracket along a material channel, the system conducts discretization and station numbering on the position of a material disc, and a servo shaft dynamically calculates a target rotation angle. Zero offset compensation is superposed according to the workpiece diameter and the tray error, so that the blank reaches a designated position, accurate positioning of a clamping jaw is ensured, and whether a workpiece exists in a discharging groove or not is judged and processed when the blank reaches a feeding and discharging station; and if no workpiece exists in the discharging groove, the second control system conducts machining connection, the main shaft drives the clamping jaw to move, positioning discharging is executed after machining is completed, then the feeding position is positioned to clamp a new blank, downward movement is conducted to trigger a bottom sensor to verify that clamping succeeds, and finally the workpiece returns to the machining area. The two systems realize stable and efficient production by controlling interactive continuous operation of each step.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical manufacturing, and in particular to an automatic feeding method for an inverted turning center. Background Art

[0002] Inverted turning is a metal cutting manufacturing process that is different from traditional turning. The characteristics of inverted turning are that the workpiece is on top, the tool is on the bottom, the spindle is fed, the turret is fixed, and the spindle completes loading and unloading. In other words, the traditional vertical lathe is turned upside down. Because it is easy to remove chips, it can effectively improve the processing quality and stability of the workpiece.

[0003] Compared with traditional vertical lathes and horizontal lathes, each inverted lathe is a complete production unit with its own material bin. People can place the workpiece on the bin to complete semi-automatic processing; it can also form a full-sequence and fully automated processing production line with an automatic loading and unloading system.

[0004] In inverted turning, the spindle completes loading and unloading. The spindle acts as a loading and unloading arm to pick up the blank and process it. After the processing is completed, the workpiece is put down again, and then the spindle returns to the specified position to wait. The workpiece is moved out of the workstation, and then it waits for the new blank to be processed to arrive before it can be clamped again. This process wastes a lot of time. Summary of the invention

[0005] In view of the above-mentioned defects, the present invention provides an automatic loading method for an inverted turning center, which can realize continuous production under multiple working conditions and improve processing efficiency through dual system control.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an automatic feeding method for an inverted turning center, comprising: Step S1: Controlling the loading of the blank through the first control system; Step S2: The bracket drives the blank to be transported along the material channel to the loading and unloading station, and detects whether there is a workpiece in the unloading trough. If there is a workpiece, the system alarms, and the bracket does not load or unload, and the bracket directly leaves the loading and unloading station. If there is no workpiece, execute step S3; The step S2 also includes: Step S201: Calculate the current bracket position and discretize the continuous angular position of the servo axis into the station number of the bracket; Step S202: Calculate the target bracket position, ensure the target station number, and prevent overflow; Step S203: generating a target rotation angle of the servo axis, and rotating the servo axis to the target angle, driving the bracket to rotate to a designated station; Step S204: Calculate the zero point offset compensation, dynamically adjust the zero point position of the servo axis according to the workpiece diameter and the bracket error, and the servo axis will add this offset when positioning to ensure that the gripping and loading position of the main axis is accurately aligned with the center of the workpiece; Step S3: Control the spindle to move to the unloading station to place the finished product through the second control system; Step S4: The spindle moves to drive the claw to position at the loading station; Step S5: the spindle moves to drive the claws to clamp the blank; Step S6: The spindle motion triggers the sensor, and the system recognizes the blank and clamps it correctly; Step S7: The spindle moves and drives the clamping claw to return to the processing space to process the blank. The first control system controls the execution of steps S1 and S2, and the second control system controls and waits for the spindle movement to drive the clamping claw to complete the processing of the workpiece, and then executes step S3 and subsequent steps.

[0007] As a further improvement of the present invention, step S2 detects whether there is a workpiece in the unloading trough at the unloading station through workpiece detection sensors that cooperate on both sides of the unloading and loading stations.

[0008] As a further improvement of the present invention, when the continuous angular position of the servo axis is discretized in step S201, every 36° corresponds to a workstation.

[0009] As a further improvement of the present invention, the target station number in step S202 cycles between 1 and 10.

[0010] As a further improvement of the present invention, in step S204, the formula involved in calculating the offset is: L2=LR / cos30°, Where L is the length from the center to the corner of the regular hexagonal feeding trough on the bracket; R is the radius of the blank workpiece; The shape of the blank is a cylindrical workpiece, and the outer circle of the blank is always tangent to the V-shaped edge on the side opposite to the moving direction of the feeding chute.

[0011] As a further improvement of the present invention, step S5 also includes detecting the diameter of the blank.

[0012] As a further improvement of the present invention, the diameter of the blank is detected by detecting the actual movement stroke G2 of the opening and closing of the jaws, and comparing the actual movement stroke G2 of the opening and closing of the jaws with the standard stroke G1.

[0013] As a further improvement of the present invention, step S6 also includes detecting the length of the blank.

[0014] As a further improvement of the present invention, the length of the blank is detected by detecting the actual time T2 when the movement of the clamping claw triggers the pressure sensor after the clamping is completed, and comparing the actual time T2 when the pressure sensor is triggered with the standard time T1.

[0015] Beneficial effects of the present invention: 1. By adopting dual control system, when the main machine runs the turning program, the loading system of the turning center can be controlled separately to carry out the normal loading and unloading process, saving the time of waiting for materials to enter and exit the loading and unloading stations and improving production efficiency.

[0016] 2. The material channel can be controlled by PLC. During the production process, if the blank with different outer diameter is replaced, it is only necessary to input the workpiece parameters in the operation interface to ensure that the workpiece can reach the specified grasping position and be clamped accurately, so as to achieve fast and stable production change.

[0017] 3. The diameter and length of the blank can be detected through the spindle control system. By detecting the diameter and length before processing, the processing accuracy can be preliminarily ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the feeding and discharging structure of the inverted turning center of the present invention; Figure 2 is a schematic diagram of the bracket; Figure 3 It is a flow chart of the automatic loading method of the inverted turning center; Figure 4 Step S2 includes the steps in the flowchart.

[0019] In the figure: 1-material placement table, 2-material channel, 3-loading and unloading station, 4-bracket, 400-loading trough, 401-unloading trough, 402-bracket fixing hole, 5-workpiece detection sensor. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific examples described herein are only used to explain the present invention and are not intended to limit the present invention. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referenced to the directions of the accompanying drawings. Therefore, the directional terms used are used to illustrate and are not used to limit the present invention. In addition, in all embodiments, the same figure numerals represent the same elements.

[0021] like Figure 1As shown, the inverted turning center includes a loading table 1. A driving unit is provided on one side of the loading table 1, and the driving unit includes a servo motor, and the servo motor is used to drive the servo rotating shaft to rotate. A material channel 2 is installed on the loading table 1, and the material channel 2 is equipped with a complete servo control system including the above-mentioned servo motor and servo drive shaft.

[0022] As a further explanation of this embodiment, the servo rotary axis refers to a rotary axis driven by a servo motor in an industrial automation system, which is used to achieve functions such as precise positioning, transmission and steering of materials on the material channel 2. It can convert the precise control characteristics of the servo motor into the actual movement of the rotary axis, thereby meeting the precise control requirements for the material transmission path.

[0023] The bracket 4 can be fixed on the material channel 2. The shape of the bracket 4 is hexagonal. Bracket fixing holes 402 are opened at the corners on opposite sides of the bracket 4. The bracket 4 can be installed on the chain on the material channel 2 by passing a cylindrical pin through the bracket fixing hole 402.

[0024] The bracket 4 is provided with an upper material trough 400 and a lower material trough 401 . Both the upper material trough 400 and the lower material trough 401 are regular hexagonal holes that completely penetrate the upper material trough 400 and the lower material trough 401 are connected at one side.

[0025] A loading and unloading station 3 is arranged on one side of the loading channel 2 of the material placement table 1, and matching workpiece detection sensors 5 are arranged on both sides of the loading and unloading station 3. The two workpiece detection sensors 5 are directly facing the unloading station of the loading and unloading station 3, and can cooperate to detect whether there is a workpiece at the unloading station.

[0026] A trigger pressure sensor is provided at the bottom of the loading station of the loading and unloading station 3 to detect and identify whether the blank is clamped.

[0027] like Figure 3 As shown, according to the above-mentioned inverted turning center, an automatic feeding method for an inverted turning center is provided, comprising: Step S1: The blank is placed into the loading trough 400 of the bracket 4 under the control of the first control system, and then the bracket 4 is placed at the feeding position of the material channel 2 .

[0028] Step S2: The bracket 4 carries the blank along the material channel 2 to the loading and unloading station 3. It is detected whether there is a workpiece in the unloading trough 401 of the bracket 4 at the loading and unloading station 3. If there is a workpiece, the system alarms, the bracket 4 does not load or unload, and the bracket 4 directly leaves the loading and unloading station 3. If there is no workpiece, step S3 is executed.

[0029] In this embodiment, step S2 also includes: in the continuous production process, when a blank with a different diameter is replaced for processing, how to accurately position the new blank in the next bracket 4 on the material channel 2 to the grasping position before entering the loading and unloading station 3.

[0030] That is, by controlling the servo rotating shaft to drive the material channel 2, when a new blank in the next bracket 4 on the material channel 2 is about to enter the loading and unloading station 3, the servo rotating shaft controls the material channel 2 so that the bracket 4 can be accurately parked in the physical space at the preset position where the workpiece is required to be grabbed or placed at the loading and unloading station 3.

[0031] This process is controlled based on the PLC control platform. The control process is as follows: Step S201: Calculate the current position of the bracket 4. Discretize the continuous angular position of the servo axis into the station number of the bracket 4 (every 36° corresponds to a station).

[0032] The PLC code corresponding to step S201 is: LDB120.DBD52; L3.600000e+001; / R; RND; TLD10; Step S202: Calculate the position of the target bracket 4. Ensure that the target station number is cycled between 1 and 10 to prevent overflow.

[0033] The PLC code corresponding to step S202 is: L1; +D; TLD14; L10; >D; JCNJJ2 ; L1; TLD14; JJ2: NOP0; Step S203: Generate a target rotation angle of the servo axis. The servo axis rotates to the target angle, driving the bracket 4 to rotate to a designated position.

[0034] The PLC code corresponding to step S203 is: LLD14; L36; *D; DTR; T#AxV_SollPos_ausSS1; Step S204: Calculate zero offset compensation. Dynamically adjust the zero position of the servo axis according to the workpiece diameter and the error of the bracket 4. The servo axis will add this offset when positioning to ensure that the gripper on the spindle is accurately aligned with the center of the workpiece.

[0035] The PLC code corresponding to step S204 is: LDB404.DBD0; L2.000000e+000; / R; L8.660254e-001; / R; LDB404.DBD8; -R; L3.600000e+002; *R; LDB404.DBD16; / R; L-1.000000e+002; *R; TRUNC; DTR; L1.000000e+002; / R; TDB404.DBD28.

[0036] As a further explanation of this embodiment, since the machine tool is not equipped with a Y-axis, in order to ensure the accuracy of material grabbing.

[0037] The zero point of the workpiece needs to be compensated in step S204, wherein the principle of the PLC program calculating the offset in step S204 is: like Figure 2 , Figure 3 , Figure 4 As shown, in this embodiment, the shape of the blanks is a cylindrical workpiece, and the outer circle of the blanks is always tangent to the V-shaped edge of the regular hexagonal feeding trough 400, and the position of the tangent V-shaped edge is always located on the side opposite to the movement direction on the material channel 2.

[0038] like Figure 2 As shown, R is the radius of the workpiece, L is the length from the center of the upper slot 400 opened on the bracket 4 to the hexagonal corner. L1 is the distance from the center of the workpiece to the hexagonal corner of the upper slot body.

[0039] According to the following formula, the offset L2 between the actual grasping position and the NC zero point is: L1=R / cos30°; L2=L-L1.

[0040] Enter the diameter of the new blank on the control panel, and the offset L2 between the actual gripping point and the NC zero point can be obtained through the above function model built into the system. The servo axis will superimpose this offset L2 during positioning to ensure that the gripping or processing position of the clamp on the spindle is accurately aligned with the center of the new blank.

[0041] Step S3: under the control of the second control system, the spindle moves to the unloading station at the unloading station 3 and places the finished parts into the unloading trough 401 of the bracket 4 .

[0042] Step S4: The spindle moves to the loading station at loading and unloading station 3 and rotates 60 degrees to correctly position the claws.

[0043] Step S5: The spindle moves downward to the clamping height, and the claws clamp the blank.

[0044] In this embodiment, step S5 also includes detecting the diameter of the blank.

[0045] A position sensor is provided on the chuck jaws installed on the main shaft to detect the movement stroke of the jaws opening and closing in the radial direction.

[0046] In S5, when the jaws clamp the standard blank, the standard stroke of the jaws opening and closing is set to G1. The stroke of the jaws opening and closing is detected by the position sensor as G2.

[0047] If G2=G1, proceed to step S6; If G2≠G1, the clamping claw does not enter step S6, the system alarms, the clamping claw directly releases the blank, the spindle moves to the starting grasping position, and waits for step S2 to run.

[0048] Step S6: The spindle continues to move downward 5 mm-10 mm, triggering the trigger sensor at the bottom of the material channel 2 at the loading station, and the system recognizes the blank and clamps it correctly.

[0049] In this embodiment, step S6 also includes detecting the length of the blank.

[0050] At the loading and unloading station 3 on the material channel 2, a trigger pressure sensor is arranged at the bottom of the loading station to detect whether the blank is clamped correctly.

[0051] In S6, when the clamping claw clamps the standard blank, the standard stroke for continued downward movement is set to H1. H1 is related to the length of the blank, but the range of H1 is always between 5mm≤H1≤10mm.

[0052] The spindle descends at a certain speed V while holding the standard blank, thereby triggering the pressure sensor. The standard time T1 from the time the claw starts to move downward from holding the blank to the time the pressure sensor is triggered.

[0053] If the length of the actual clamped workpiece is greater than the length of the standard blank, after the clamping of the claws, the margin below the actual clamped blank is greater than the margin below the standard blank clamped by the claws, and the standard downward movement stroke H2 of the actual blank clamped by the claws is less than H1. When the spindle moves downward at a certain speed V, the pressure sensor will be triggered in advance, and the actual time T2 of the claw movement triggering the pressure sensor is less than the standard time T1.

[0054] If the length of the workpiece actually clamped is less than the length of the standard blank, after the clamping of the claws, the margin below the actual clamped blank is less than the margin below the standard blank clamped by the claws, and the standard downward movement of the actual blank clamped by the claws is greater than H1. When the spindle moves downward at a certain speed V and triggers the pressure sensor, the actual time T2 of the claw movement triggering the pressure sensor is greater than the standard time T1.

[0055] If the workpiece is too short, when the actual movement stroke H2 of the clamping jaw reaches the maximum standard stroke 10mm, it may still not trigger the pressure sensor. The actual time T2 of the clamping jaw movement triggering the pressure sensor is also greater than the standard time T1, and the workpiece can still be deemed unqualified.

[0056] The system detects that in step S6: If T2 = T1, proceed to step S7; If T2≠T1, the clamping jaw does not enter step S6, the system alarms, the clamping jaw moves upward to the initial clamping position in step S5, releases the blank, and then the spindle moves to the starting grasping position, waiting for step S2 to run.

[0057] Step S7: the spindle returns to the processing space to process the blank; the first control system controls steps S1 and S2 to perform normal loading and feeding, and after the clamp on the spindle completes the processing of the workpiece, it controls through the second control system to run step S3 and subsequent steps.

[0058] The above process is controlled by adopting a dual control system. When the main machine runs the turning program, the loading and unloading systems of the turning center can be controlled separately to carry out normal loading and unloading processes, and is suitable for continuous production and monitoring of various working conditions.

[0059] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above implementation measures. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An automatic feeding method for an inverted turning center, characterized in that: include: Step S1: Controlling the loading of the blank through the first control system; Step S2: The bracket drives the blank to be transported along the material channel to the loading and unloading station, and detects whether there is a workpiece in the unloading trough. If there is a workpiece, the system alarms, and the bracket does not load or unload, and the bracket directly leaves the loading and unloading station. If there is no workpiece, execute step S3; The step S2 also includes: Step S201: Calculate the current bracket position and discretize the continuous angular position of the servo axis into the station number of the bracket; Step S202: Calculate the target bracket position, ensure the target station number, and prevent overflow; Step S203: generating a target rotation angle of the servo axis, and rotating the servo axis to the target angle, driving the bracket to rotate to a designated station; Step S204: Calculate the zero point offset compensation, dynamically adjust the zero point position of the servo axis according to the workpiece diameter and the bracket error, and the servo axis will add this offset when positioning to ensure that the gripping and loading position of the main axis is accurately aligned with the center of the workpiece; Step S3: Control the spindle to move to the unloading station to place the finished product through the second control system; Step S4: The spindle moves to drive the claw to position at the loading station; Step S5: the spindle moves to drive the claws to clamp the blank; Step S6: The spindle movement triggers the sensor, and the system recognizes the blank and clamps it correctly; Step S7: The spindle moves and drives the clamping claw to return to the processing space to process the blank. The first control system controls the execution of steps S1 and S2, and the second control system controls and waits for the spindle movement to drive the clamping claw to complete the processing of the workpiece, and then executes step S3 and subsequent steps.

2. The automatic feeding method of the inverted turning center according to claim 1 is characterized in that: In step S2, the workpiece detection sensors matched at both sides of the loading and unloading stations are used to detect whether there is a workpiece in the unloading trough at the unloading station.

3. The automatic feeding method of an inverted turning center according to claim 1, characterized in that: When the continuous angular position of the servo axis is discretized in step S201, every 36° corresponds to a workstation.

4. The automatic feeding method of an inverted turning center according to claim 1, characterized in that: In step S202, the target station number cycles between 1 and 10.

5. The automatic feeding method of an inverted turning center according to claim 1, characterized in that: In step S204, the formula involved in calculating the offset is: L2=LR / cos30°, Where L is the length from the center to the corner of the regular hexagonal feeding trough on the bracket; R is the radius of the blank workpiece; The shape of the blank is a cylindrical workpiece, and the outer circle of the blank is always tangent to the V-shaped edge on the side opposite to the moving direction of the feeding chute.

6. The automatic feeding method of an inverted turning center according to claim 1, characterized in that: The step S5 also includes detecting the diameter of the blank.

7. The automatic feeding method of an inverted turning center according to claim 6, characterized in that: The detection of the diameter of the blank is obtained by detecting the actual movement stroke G2 of the opening and closing of the clamping jaws, and comparing the actual movement stroke G2 of the opening and closing of the clamping jaws with the standard stroke G1.

8. The automatic feeding method of an inverted turning center according to claim 1, characterized in that: The step S6 also includes detecting the length of the blank.

9. The automatic feeding method of an inverted turning center according to claim 8, characterized in that: The length of the blank is detected by detecting the actual time T2 of the pressure sensor being triggered by the movement of the clamping claw after the clamping is completed, and comparing the actual time T2 of the pressure sensor being triggered with the standard time T1.

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