C-axis switching control device and method for main shaft of turning and milling composite machine tool

Abstract

The invention relates to the technical field of machine tool control, in particular to a turning-milling composite machine tool spindle C-axis switching control device and method, and the turning-milling composite machine tool spindle C-axis switching control device comprises a machine tool and a switching control mechanism arranged on the machine tool. The switching control mechanism comprises a first driving assembly and a main shaft box which are arranged on the machine tool body, a main shaft rotationally connected to the main shaft box, a sliding shifting fork assembly arranged on the main shaft box, a worm wheel rotationally connected to the main shaft through a bearing, a sliding end-toothed disc arranged on the main shaft in a sliding mode and a second driving assembly arranged on the main shaft box. The first driving assembly is in transmission connection with the main shaft and drives the main shaft to rotate, the worm gear is provided with a fixed end-toothed disc arranged opposite to the tooth surface of the sliding end-toothed disc, and the second driving assembly is in transmission connection with the worm gear and drives the worm gear to rotate; through precise control of the relative positions of the fluted discs and cooperative action of the main shaft servo motor and the C-axis servo motor, friction and abrasion between the fluted discs are effectively reduced, the service life of the fluted discs is prolonged, and the equipment maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool control, and in particular to a C-axis switching control device and method for a main spindle of a turning-milling compound machine tool. Background Art

[0002] During the machining process of a turning-milling machine tool, the spindle C-axis needs to be switched when the turning-milling machining mode is changed. At present, when the spindle is in a stopped state, the spindle C-axis switching control device of most turning-milling machine tools rotates the worm gear side end gear plate loosely sleeved on the spindle at a low speed through the C-axis, and instructs the oil cylinder to push the fork and the sliding mechanism to complete the engagement of the end gear plate. However, this traditional switching control method has many disadvantages, and is prone to top tooth phenomenon, resulting in serious wear between gear plates, long meshing time, and large mechanical impact during the meshing process, which seriously affects the machining efficiency and service life of the machine tool, and is not conducive to ensuring machining accuracy. Summary of the invention

[0003] The object of the present invention is to provide a C-axis switching control device and method for a turning-milling compound machine tool spindle, which are used to solve the problems existing in the existing methods mentioned in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a C-axis switching control device and method for a turning-milling compound machine tool spindle, comprising a machine tool and a switching control mechanism arranged on the machine tool, the switching control mechanism comprising a first driving assembly and a spindle box arranged on a machine tool bed, a spindle rotatably connected to the spindle box, a sliding fork assembly arranged on the spindle box, a worm gear rotatably connected to the spindle through a bearing, a sliding end gear plate slidably arranged on the spindle, and a second driving assembly arranged on the spindle box; the first driving assembly is connected to the spindle in a transmission manner, and the first driving assembly drives the spindle to rotate, the worm wheel is provided with a fixed end gear plate arranged opposite to the tooth surface of the sliding end gear plate, and the second driving assembly is connected to the worm wheel in a transmission manner, and the second driving assembly drives the worm wheel to rotate.

[0005] Furthermore, a control switch group is provided on the spindle box, and the control switch group includes a C-axis position feedback circular grating, a spindle position encoder, a gear disc engagement detection switch and a gear disc zero position detection switch arranged on the spindle box, the C-axis position feedback circular grating is loosely mounted on the spindle, the C-axis position feedback circular grating is used to measure the rotational position of the C-axis, the spindle position encoder is used to detect the spindle position, the gear disc engagement detection switch is used to detect the engagement state of the gear disc, and the gear disc zero position detection switch is used to detect whether the fixed end gear disc is in a specific zero position reference position.

[0006] Furthermore, the first driving assembly includes a spindle servo motor arranged on the machine tool bed and a pulley group arranged on the spindle; the output shaft of the spindle servo motor is connected to the pulley group through a belt.

[0007] Furthermore, the sliding fork assembly includes a cylinder arranged on the main spindle box and a fork rod connected to the cylinder output shaft; a sliding groove is opened on the outer wall of the sliding end gear plate, and the end of the fork rod is located in the sliding groove and slides with the sliding groove.

[0008] Furthermore, the second driving assembly includes a C-axis servo motor disposed on the spindle box and a worm connected to an output shaft of the C-axis servo motor; the worm is meshed with a worm wheel.

[0009] Furthermore, the C-axis position feedback circular grating, the spindle position encoder, the gear disc combination detection switch, the gear disc zero position detection switch, the spindle servo motor, the oil cylinder and the C-axis servo motor are all connected to the PLC controller built into the CNC numerical control system.

[0010] Furthermore, the switching control process from the spindle to the C-axis is included, and the specific steps are as follows: 1) CNC reads the processing execution program; 2) If the switch from the spindle to the C-axis is confirmed, the PLC controller detects whether it is currently in the C-axis mode. If it is in the C-axis mode, it ends the execution of the next program; if it is not in the C-axis mode, it executes the spindle to C-axis switch program; 3) First, the spindle servo motor performs spindle orientation control, the tooth root of the sliding end gear disc stops at a fixed position, and the C-axis servo motor returns to the reference point, and then the C-axis rotates at a low speed. When the gear disc zero position detection switch detects the tooth top switch signal on the fixed end gear disc; 4) PLC issues instructions to control the action of the hydraulic cylinder; 5) The sliding end gear disc and the fixed end gear disc are combined in quick action to complete the spindle C-axis switching.

[0011] 8. The control method of a spindle C-axis switching control device of a turning-milling compound machine tool according to claim 7 is characterized in that, in the step, the spindle servo motor performs spindle orientation control and the C-axis servo motor returns to the reference point and rotates at a low speed in order to accurately adjust the relative position of the sliding end gear disc and the fixed end gear disc to achieve correct meshing.

[0012] Furthermore, the switching control process from the C-axis to the main axis includes the following specific steps: 1) CNC reads the parts processing execution program; 2) If it is confirmed to execute the switch from C axis to spindle, the PLC controller will detect whether it is currently in spindle mode. If it is in spindle mode, it will end the execution of the next program; if it is not in spindle mode, it will execute the C axis to spindle switch program; 3) The PLC controller issues a command and the cylinder moves; 4) The oil cylinder drives the sliding end gear disc to move, so that the sliding end gear disc and the fixed end gear disc are separated, thus completing the C-axis spindle switching.

[0013] Furthermore, in the step, when the PLC controller determines according to the control logic that a switch from the C-axis to the main axis is required, it directly issues a command to control the movement of the oil cylinder.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Reduce the wear of the gear disc; the traditional method is prone to top gear phenomenon when switching when the spindle is stopped, resulting in serious wear of the gear disc. The present invention accurately controls the relative position of the gear disc, such as the coordinated action of the spindle servo motor and the C-axis servo motor, so that the gear disc is combined at the appropriate position, effectively reducing the friction and wear between the gear discs, extending the service life of the gear disc, and reducing the equipment maintenance cost.

[0015] 2. Shorten the meshing time. The meshing process of the previous method is complicated and the mechanical impact is large. The control method of the present invention enables the gear disc to be quickly and accurately engaged or separated. When switching from the spindle to the C-axis, each step is closely coordinated. Once the gear disc zero position detection switch detects a signal, the engagement can be completed quickly. When switching from the C-axis to the spindle, the PLC directly controls the cylinder action to quickly separate the gear disc, which greatly shortens the switching time and improves the machining efficiency of the machine tool.

[0016] 3. Reduce mechanical shock; precise control strategy avoids mechanical shock caused by forced engagement or separation of the gear disc; during the switching process, the orderly movement of the spindle servo motor and the C-axis servo motor and the precise positioning of the sliding end gear disc and the fixed end gear disc make the gear disc engagement and separation process smooth, reduce the impact on the mechanical structure of the machine tool, improve the stability of the machine tool, and help ensure processing accuracy and improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the overall structure diagram of the present invention; Figure 2 It is a side view of the present invention; Figure 3 It is the operation flow chart of the present invention; Figure 4 This is a system block diagram of the present invention.

[0018] In the figure: 1. Spindle box; 2. Spindle; 3. Worm gear; 4. Sliding end gear disc; 5. Fixed end gear disc; 6. C-axis position feedback circular grating; 7. Spindle position encoder; 8. Gear disc combination detection switch; 9. Gear disc zero position detection switch; 10. Spindle servo motor; 11. Pulley assembly; 12. Cylinder; 13. Fork lever; 14. C-axis servo motor; 15. Worm. DETAILED DESCRIPTION

[0019] See also Figures 1 to 4 A C-axis switching control device and method for a turning-milling compound machine tool spindle is provided. A spindle servo motor 10 is installed on a machine tool bed, and its output shaft is connected to a pulley set 11 on a spindle 2 through a belt, so as to realize the transmission connection between the first drive assembly and the spindle 2. An oil cylinder 12 is installed on a spindle box 1, and a fork rod 13 is connected to the output shaft of the oil cylinder 12, and the end of the fork rod 13 is located in a sliding groove on the outer wall of a sliding end gear plate 4 and slides together to complete the installation of the sliding fork assembly; a C-axis servo motor 14 is installed on the spindle box 1, and a worm 15 is connected to the worm 15. The worm gear 3 is meshed to realize the transmission connection between the second drive component and the worm gear 3; at the same time, the C-axis position feedback circular grating 6, the spindle position encoder 7, the gear combination detection switch 8, and the gear zero position detection switch 9 are installed on the spindle box 1, and the C-axis position feedback circular grating 6 is empty on the spindle 2, and the C-axis position feedback circular grating 6, the spindle position encoder 7, the gear combination detection switch 8, the gear zero position detection switch 9, the spindle servo motor 10, the cylinder 12 and the C-axis servo motor 14 are all connected to the built-in PLC controller of the CNC numerical control system.

[0020] After starting the machine tool, the CNC reads in the processing execution program. When the PLC controller confirms the execution of the switch from the spindle to the C-axis and is not currently in the C-axis mode, the switching program is started; the spindle servo motor 10 performs spindle orientation control to stop the tooth root of the sliding end gear disc 4 at a fixed position; at the same time, the C-axis servo motor 14 moves back to the reference point, and then the C-axis rotates at a low speed until the gear disc zero position detection switch 9 detects the tooth top switch signal on the fixed end gear disc 5; the PLC issues a command to control the hydraulic cylinder 12 to move, push the fork rod 13 to drive the sliding end gear disc 4 to move, so that it can quickly combine with the fixed end gear disc 5 to complete the drive switching of the spindle C axis. At this time, the spindle servo motor 10 does not work, and the C-axis servo motor 14 provides power.

[0021] Similarly, the CNC reads the part processing execution program. When the PLC controller confirms the execution of the switch from the C-axis to the spindle and is not in the spindle mode, the switching program is executed; the PLC controller directly issues a command to control the action of the cylinder 12, and the cylinder 12 drives the sliding end gear plate 4 to move, so that the sliding end gear plate 4 and the fixed end gear plate 5 are separated, realizing the drive switch from the C-axis to the spindle. At this time, the C-axis servo motor 14 does not work, and the spindle servo motor 10 provides power.

[0022] Working principle of the present invention: During the switching process between the spindle and the C-axis, precise control is achieved through the coordinated work of sensors and controllers such as the C-axis position feedback circular grating 6, the spindle position encoder 7, the toothed disc combination detection switch 8, and the toothed disc zero position detection switch 9. The C-axis position feedback circular grating 6 measures the rotation position of the C-axis in real time to provide data reference for position adjustment when the spindle and the C-axis are switched; the spindle position encoder 7 detects the spindle position to ensure that the spindle is in the correct state before the switching operation; the toothed disc combination detection switch 8 and the toothed disc zero position detection switch 9 respectively monitor the toothed disc combination state and the zero position reference position of the fixed end toothed disc 5 to ensure the accuracy of the toothed disc combination and separation operations.

[0023] When switching from the spindle to the C-axis, the directional control of the spindle servo motor 10 and the return to the reference point and low-speed rotation of the C-axis servo motor 14 accurately adjust the relative positions of the sliding-end gear disc 4 and the fixed-end gear disc 5 to avoid the top tooth phenomenon and achieve accurate meshing; when switching from the C-axis to the spindle, the PLC directly controls the action of the cylinder 12 according to the control logic, quickly separates the gear disc, and restores the normal rotation of the spindle.

Claims

1. A C-axis switching control device for a turning-milling compound machine tool spindle, comprising a machine tool and a switching control mechanism arranged on the machine tool, characterized in that: The switching control mechanism comprises a first driving assembly and a spindle box (1) arranged on a machine tool bed, a spindle (2) rotatably connected to the spindle box (1), a sliding fork assembly arranged on the spindle box (1), a worm wheel (3) rotatably connected to the spindle (2) via a bearing, a sliding end toothed disc (4) slidably arranged on the spindle (2), and a second driving assembly arranged on the spindle box (1); the first driving assembly is in driving connection with the spindle (2), and the first driving assembly drives the spindle (2) to rotate; the worm wheel (3) is provided with a fixed end toothed disc (5) arranged opposite to the tooth surface of the sliding end toothed disc (4); the second driving assembly is in driving connection with the worm wheel (3), and the second driving assembly drives the worm wheel (3) to rotate.

2. The C-axis switching control device for a turning-milling compound machine tool spindle according to claim 1, characterized in that: The spindle box (1) is provided with a control switch group, which includes a C-axis position feedback circular grating (6), a spindle position encoder (7), a toothed disc combination detection switch (8) and a toothed disc zero position detection switch (9) arranged on the spindle box (1), the C-axis position feedback circular grating (6) is loosely mounted on the spindle (2), the C-axis position feedback circular grating (6) is used to measure the rotational position of the C-axis, the spindle position encoder (7) is used to detect the spindle position, the toothed disc combination detection switch (8) is used to detect the combination state of the toothed disc, and the toothed disc zero position detection switch (9) is used to detect whether the fixed end toothed disc (5) is in a specific zero position reference position.

3. The C-axis switching control device for a turning-milling compound machine tool spindle according to claim 2, characterized in that: The first drive assembly comprises a spindle servo motor (10) arranged on a machine tool bed, and a pulley group (11) arranged on a spindle (2); the output shaft of the spindle servo motor (10) is connected to the pulley group (11) via a belt.

4. The C-axis switching control device for a turning-milling compound machine tool spindle according to claim 3 is characterized in that: The sliding fork assembly comprises an oil cylinder (12) arranged on the main spindle box (1), and a fork rod (13) connected to the output shaft of the oil cylinder (12); a sliding groove is provided on the outer wall of the sliding end gear plate (4), and the end of the fork rod (13) is located in the sliding groove and slides in cooperation with the sliding groove.

5. The C-axis switching control device for a turning-milling compound machine tool spindle according to claim 4, characterized in that: The second drive assembly comprises a C-axis servo motor (14) arranged on the spindle box (1), and a worm (15) connected to the output shaft of the C-axis servo motor (14); the worm (15) is meshed with the worm wheel (3).

6. The C-axis switching control device for a turning-milling compound machine tool spindle according to claim 5, characterized in that: The C-axis position feedback circular grating (6), the spindle position encoder (7), the toothed disc combination detection switch (8), the toothed disc zero position detection switch (9), the spindle servo motor (10), the oil cylinder (12) and the C-axis servo motor (14) are all connected to a PLC controller built into the CNC numerical control system.

7. The control method of the C-axis switching control device of a turning-milling compound machine tool spindle according to any one of claims 1 to 6, characterized in that: Including the switching control process from the spindle to the C axis, the specific steps are as follows: 1) CNC reads the processing execution program; 2) If the switch from the spindle to the C-axis is confirmed, the PLC controller detects whether it is currently in the C-axis mode. If it is in the C-axis mode, it ends the execution of the next program; if it is not in the C-axis mode, it executes the spindle to C-axis switch program; 3) First, the spindle servo motor (10) performs spindle orientation control, and the tooth root of the sliding end gear disc (4) stops at a fixed position. At the same time, the C-axis servo motor (14) moves back to the reference point, and then the C-axis rotates at a low speed. When the gear disc zero position detection switch (9) detects the tooth top switch signal on the fixed end gear disc (5); 4) The PLC issues a command to control the hydraulic cylinder (12) to move; 5) The sliding end gear disc (4) and the fixed end gear disc (5) quickly move together to complete the spindle C-axis switching.

8. The control method of the C-axis switching control device of a turning-milling compound machine tool spindle according to claim 7 is characterized in that: In step 3), the spindle servo motor (10) performs spindle orientation control and the C-axis servo motor (14) returns to the reference point and rotates at a low speed in order to accurately adjust the relative position of the sliding end gear disc (4) and the fixed end gear disc (5) to achieve correct meshing.

9. The control method of the C-axis switching control device of a turning-milling compound machine tool spindle according to claim 7, characterized in that: Including the switching control process from the C-axis to the spindle, the specific steps are as follows: 1) CNC reads the parts processing execution program; 2) If the switch from C-axis to spindle is confirmed, the PLC controller detects whether it is currently in spindle mode. If it is in spindle mode, it ends the execution of the next program; If it is not in spindle mode, execute the C-axis to spindle switching procedure; 3) The PLC controller issues a command, and the cylinder (12) moves; 4) The oil cylinder (12) drives the sliding end gear disc (4) to move, so that the sliding end gear disc (4) and the fixed end gear disc (5) are separated, thereby completing the C-axis spindle switching.

10. The control method of the C-axis switching control device of a turning-milling compound machine tool spindle according to claim 9, characterized in that: In step 3), when the PLC controller determines according to the control logic that the C-axis needs to be switched to the main axis, it directly issues a command to control the action of the oil cylinder (12).

Images