Novel machining center automatic tool changing system and tool arm control method using same

Abstract

The invention discloses a novel machining center automatic tool changing system and a tool arm control method using the system, which are applied to the field of motors and control thereof.The novel machining center automatic tool changing system comprises an automatic tool changing device which comprises a machine body, a tool arm driving device and a tool arm capable of being driven to rotate, and the tool arm driving device and the tool arm driving device are arranged above and below the machine body respectively; a Hall sensor is arranged in a motor for driving the tool arm driving device and is used for recording the operation position of the tool arm; the homing detection device comprises a signal wheel and an original point sensor which is arranged above the signal wheel and is mounted at the homing position of the tool arm; when the tool arm runs to the homing device, the original point sensor is triggered, and an original point signal is transmitted to the motor driving device; and the motor driving device is used for recording a preset tool arm operation position, accumulatively recording a Hall signal pulse number to drive a motor, simultaneously feeding back the tool arm operation position to a machine tool master controller, and resetting the accumulatively recorded Hall signal pulse number when an original point signal is received. According to the invention, the tool arm control cost is effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of motors and control thereof, and in particular to a novel automatic tool changing system for a machining center and a tool arm control method utilizing the system. Background Art

[0002] In the field of automated machining, in order to meet the needs of various machining processes such as boring, milling, cutting, shaving, and drilling, the machining tools need to be adjusted in time, and the automatic tool changing system came into being. The automatic tool changing system is mainly divided into two parts: the tool magazine and the tool arm. The tool magazine is used to store different tools, and the tool arm is used to perform tool changing actions. Taking a simple disc-type tool changing mechanism as an example, its power source is a three-phase asynchronous motor. The tool changing action of the tool arm can be subdivided into three positions: picking up the tool, inserting the tool, and returning to the original position. These three positions need to be detected and distinguished when performing tool changing actions. The existing solution uses a chain to link the signal wheel with the camshaft in the tool arm deceleration mechanism. At the same time, three photoelectric sensors are installed near the signal wheel to detect the position of the tool arm.

[0003] However, the above devices have the following disadvantages: First, the power source uses a three-phase asynchronous motor, which has low efficiency and large size. It also needs to be equipped with a special mechanical brake, which has poor braking effect, easy wear of the brake pads, and needs to be replaced regularly. Second, since the location for installing the signal wheel is relatively small and multiple sensors need to be installed at the same time, the size requirements of the sensors are strict, resulting in high prices for the sensors.

[0004] To this end, how to provide a new automatic tool changing system for a machining center and a tool arm control method using the system that can effectively solve the problem of expensive sensors caused by too many sensors needing to be installed at the same time and the relatively narrow space for installing the signal wheel, as well as the problem of low efficiency, large size, regular maintenance and short life of the power source, are issues that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of this, the present invention proposes a novel automatic tool changing system for a machining center and a tool arm control method using the system.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A new type of automatic tool changing system for a machining center, comprising: an automatic tool changing device, a homing detection device and a motor driving device;

[0008] The automatic tool changing device comprises: a machine body, a knife arm driving device arranged above the machine body, and a knife arm arranged below the machine body and capable of being driven to rotate; a motor driving the knife arm driving device has a built-in Hall sensor for recording the running position of the knife arm;

[0009] The homing detection device comprises: a signal wheel and an origin sensor arranged above the signal wheel and installed at the homing position of the knife arm; the signal wheel is connected to the machine body through a chain and rotates with the knife arm. When the knife arm runs to the homing device, the origin sensor is triggered and the origin signal is transmitted to the motor drive device;

[0010] The motor drive device is used to record the preset tool arm running position, accumulate and record the number of Hall signal pulses of the Hall sensor to drive the motor, and at the same time feed back the tool arm running position to the machine tool main control. When the origin signal is received, the accumulated number of Hall signal pulses is cleared.

[0011] Optionally, a transmission group and a cam shaft are provided in the machine body, and the knife arm driving device drives the cam shaft and the knife arm to move through the transmission group.

[0012] Optionally, the motor driving the knife arm driving device is a permanent magnet synchronous motor.

[0013] Optionally, the motor drive device is provided with a first button and a second button, the first button is for entering a preset mode, and the second button is for recording and setting;

[0014] Record the preset knife arm running position, specifically:

[0015] When the preset mode is entered by pressing the first button, the motor maintains a low speed. When the knife arm moves to the knife picking position, the enable signal is canceled, and the number of pulses at the knife picking position is recorded and set by pressing the second button. The motor is re-enabled. When the knife arm moves to the knife inserting position, the enable signal is canceled, and the number of pulses at the knife inserting position is recorded and set by pressing the second button. After completing the preset of the knife picking position and the knife inserting position, the preset mode is exited by pressing the first button, and the motor returns to normal speed.

[0016] The present invention also provides a tool arm control method using a novel automatic tool changing system of a machining center, comprising:

[0017] Step 1: The machine tool master sends an enable signal to the motor drive device to drive the motor to run, drive the tool arm to rotate, and accumulate and record the number of Hall signal pulses of the Hall sensor;

[0018] Step 2: When the accumulated value of the Hall signal pulse number is equal to the preset number of pulses of the tool removal position, the motor drive device controls the motor brake and feeds back the tool removal position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling the output and disconnects the tool and the spindle;

[0019] Step 3: The machine tool master controller sends an enable signal to the motor drive device again to drive the motor to run, drive the tool arm to rotate, and accumulate and record the number of Hall signal pulses of the Hall sensor;

[0020] Step 4: When the accumulated value of the Hall signal pulse number is equal to the preset number of pulses of the inserting tool position, the motor drive device controls the motor brake and feeds back the inserting tool position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling the output and restores the connection between the tool and the spindle;

[0021] Step 5: The machine tool main control sends an enable signal to the motor drive device again to drive the motor to run, drive the tool arm to rotate, and accumulate and record the number of Hall signal pulses of the Hall sensor;

[0022] Step 6: When the tool arm moves to the home position, the motor drive device receives the origin signal transmitted by the origin sensor, controls the motor brake, and feeds back the home position signal to the machine tool main control, clearing the accumulated number of Hall signal pulses. After receiving the signal, the machine tool main control stops enabling the output and completes the entire tool changing action.

[0023] It can be seen from the above technical solutions that, compared with the prior art, the present invention proposes a new automatic tool changing system for machining centers and a tool arm control method using the system. The present invention drives the permanent magnet synchronous motor based on the Hall signal and the cumulative pulse number of the preset tool arm running position through the Hall sensor installed inside the permanent magnet synchronous motor, and only retains one origin sensor in the three sensor solutions in the prior art for tool arm homing detection, which effectively solves the problem of expensive sensors caused by the strict sensor size requirements caused by too many sensors required to be installed at the same time and the relatively narrow position for installing the signal wheel in the prior art. In addition, the permanent magnet synchronous motor also has the advantages of reliable performance, low failure rate, high efficiency, small size, long life and low maintenance cost, which effectively solves the problems of low efficiency, large size, regular maintenance and short life of the power source. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly 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 will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the device structure of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the built-in Hall sensor in the motor of the present invention.

[0027] Figure 3 It is a schematic structural diagram of the homing detection device of the present invention.

[0028] Figure 4It is a schematic diagram of the structure of the motor drive device of the present invention.

[0029] Figure 5 The present invention is a flow chart of a method for recording a preset knife arm operating position.

[0030] Figure 6 It is a schematic diagram of the signal transmission relationship of the present invention.

[0031] Figure 7 It is a schematic flow chart of the knife arm control method of the present invention.

[0032] Among them, 1-automatic tool changing device, 2-home detection device, 3-motor driving device, 11-machine body, 12-knife arm driving device, 13-knife arm, 121-motor, 1211-Hall sensor, 21-signal wheel, 22-origin sensor, 31-first button, 32-second button. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1:

[0035] Embodiment 1 of the present invention discloses a novel automatic tool changing system for a machining center, such as Figure 1 As shown, it includes: an automatic tool changing device 1, a homing detection device 2 and a motor driving device 3;

[0036] The automatic tool changing device 1 comprises: a machine body 11, a knife arm driving device 12 arranged above the machine body 11, and a knife arm 13 arranged below the machine body 11 and capable of being driven to rotate; a motor 121 driving the knife arm driving device 12 has a built-in Hall sensor 1211 for recording the running position of the knife arm 13;

[0037] The homing detection device 2 includes: a signal wheel 21 and an origin sensor 22 arranged above the signal wheel 21 and installed at the homing position of the knife arm 13; the signal wheel 21 is connected to the body 11 through a chain and rotates with the knife arm 13. When the knife arm 13 runs to the homing device, the origin sensor 22 is triggered and the origin signal is transmitted to the motor drive device 3;

[0038] The motor drive device 3 is used to record the preset tool arm operating position, and accumulate and record the number of Hall signal pulses of the Hall sensor 1211 to drive the motor 121, and at the same time feed back the tool arm operating position to the machine tool main control. When the origin signal is received, the accumulated number of Hall signal pulses is cleared to eliminate error accumulation and ensure the accuracy of the tool arm operating position.

[0039] A transmission group and a cam shaft are arranged in the machine body 11, and the knife arm driving device 12 drives the cam shaft and the knife arm 13 to move through the transmission group.

[0040] The motor 121 driving the knife arm driving device 12 is a permanent magnet synchronous motor.

[0041] The motor drive device 3 is provided with a first button 31 and a second button 32. The first button 31 is for entering a preset mode, and the second button 32 is for recording and setting.

[0042] Record the preset knife arm running position, such as Figure 5 As shown, specifically:

[0043] When the preset mode is entered by the first button 31, the motor 121 maintains a low speed. When the knife arm 13 moves to the knife taking position, the enable signal is canceled, and the pulse number of the knife taking position is recorded and set by the second button 32. The motor 121 is re-enabled. When the knife arm 13 moves to the knife inserting position, the enable signal is canceled, and the pulse number of the knife inserting position is recorded and set by the second button 32. After completing the preset of the knife taking position and the knife inserting position, the preset mode is exited by the first button 31, and the motor 121 returns to normal speed.

[0044] The motor drive device 3 also has a power-off memory function, ensuring that even after encountering an emergency such as a power outage, the knife arm 13 can continue to perform the knife changing operation before the power outage, avoiding damage to the motor 121 and the mechanism due to power outage shock and restart.

[0045] The signal transmission relationship in the present invention is as follows: Figure 6 shown.

[0046] The present invention also provides a tool arm control method using a novel automatic tool changing system of a machining center, such as Figure 7 As shown, including:

[0047] Step 1: The machine tool master sends an enable signal to the motor drive device 3 to drive the motor 121 to run, drive the knife arm 13 to rotate, and accumulate and record the number of Hall signal pulses of the Hall sensor 1211;

[0048] Step 2: When the cumulative value of the number of Hall signal pulses is equal to the number of pulses of the preset tool removal position, the motor drive device 3 controls the motor 121 to brake, and feeds back the tool removal position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling the output and disconnects the tool and the spindle;

[0049] Step 3: The machine tool master controller sends an enable signal to the motor drive device 3 again, drives the motor 121 to run, drives the knife arm 13 to rotate, and accumulates and records the number of Hall signal pulses of the Hall sensor 1211;

[0050] Step 4: When the cumulative value of the number of Hall signal pulses is equal to the number of pulses of the preset inserting tool position, the motor drive device 3 controls the motor 121 to brake, and feeds back the inserting tool position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling the output and restores the connection between the tool and the spindle;

[0051] Step 5: The machine tool master controller sends an enable signal to the motor drive device 3 again, drives the motor 121 to run, drives the knife arm 13 to rotate, and accumulates and records the number of Hall signal pulses of the Hall sensor 1211;

[0052] Step 6: When the tool arm 13 runs to the home position, the motor drive device 3 receives the origin signal transmitted by the origin sensor 22, controls the motor 121 to brake, and feeds back the home position signal to the machine tool main control, clearing the accumulated number of Hall signal pulses. After receiving the signal, the machine tool main control stops enabling the output and completes the entire tool changing action.

[0053] The embodiment of the present invention discloses a novel automatic tool changing system for a machining center and a knife arm control method using the system. The present invention drives the permanent magnet synchronous motor based on the Hall signal and the cumulative pulse number of the preset knife arm running position through the Hall sensor installed inside the permanent magnet synchronous motor, and only retains one origin sensor in the three sensor schemes in the prior art for knife arm homing detection, which effectively solves the problem of expensive sensors caused by too many sensors required to be installed at the same time and the relatively narrow position for installing the signal wheel in the prior art. In addition, the permanent magnet synchronous motor also has the advantages of reliable performance, low failure rate, high efficiency, small size, long life and low maintenance cost, which effectively solves the problems of low efficiency, large size, regular maintenance and short life of the power source.

[0054] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0055] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A new type of automatic tool changing system for machining center, characterized in that: include: Automatic tool changing device (1), homing detection device (2) and motor driving device (3); The automatic tool changing device (1) comprises: a machine body (11), a knife arm driving device (12) arranged above the machine body (11), and a knife arm (13) arranged below the machine body (11) and capable of being driven to rotate; a motor (121) driving the knife arm driving device (12) has a built-in Hall sensor (1211) for recording the operating position of the knife arm (13); The homing detection device (2) comprises: a signal wheel (21) and an origin sensor (22) arranged above the signal wheel (21) and installed at the homing position of the knife arm (13); the signal wheel (21) is connected to the machine body (11) through a chain and rotates with the knife arm (13); when the knife arm (13) runs to the homing device, the origin sensor (22) is triggered and the origin signal is transmitted to the motor drive device (3); The motor drive device (3) is used to record the preset knife arm operating position, and accumulate and record the number of Hall signal pulses of the Hall sensor (1211) to drive the motor (121), and at the same time feed back the knife arm operating position to the machine tool main control, and when the origin signal is received, the accumulated number of Hall signal pulses is cleared.

2. A new type of automatic tool changing system for machining center according to claim 1, characterized in that: A transmission group and a cam shaft are provided in the machine body (11), and the knife arm driving device (12) drives the cam shaft and the knife arm (13) to move through the transmission group.

3. The new automatic tool changing system for machining center according to claim 1 is characterized in that: The motor (121) driving the knife arm driving device (12) is a permanent magnet synchronous motor.

4. The new automatic tool changing system for machining center according to claim 1 is characterized in that: The motor drive device (3) is provided with a first button (31) and a second button (32), wherein the first button (31) is used to enter a preset mode, and the second button (32) is used to record and set; Record the preset knife arm running position, specifically: When the preset mode is entered by pressing the first button (31), the motor (121) maintains a low rotation speed; when the knife arm (13) moves to the knife taking position, the enable signal is cancelled, and the number of pulses at the knife taking position is recorded and set by pressing the second button (32); the motor (121) is re-enabled; when the knife arm (13) moves to the knife inserting position, the enable signal is cancelled, and the number of pulses at the knife inserting position is recorded and set by pressing the second button (32); after completing the preset of the knife taking position and the knife inserting position, the preset mode is exited by pressing the first button (31), and the motor (121) returns to a normal rotation speed.

5. A tool arm control method using a new type of automatic tool changing system for a machining center according to any one of claims 1 to 4, characterized in that: include: Step 1: The machine tool main control sends an enable signal to the motor drive device (3), driving the motor (121) to run, driving the knife arm (13) to rotate, and accumulating and recording the number of Hall signal pulses of the Hall sensor (1211); Step 2: When the cumulative value of the number of Hall signal pulses is equal to the number of pulses of the preset tool removal position, the motor drive device (3) controls the motor (121) to brake, and feeds back the tool removal position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling output and disconnects the tool and the spindle; Step 3: the machine tool main control again sends an enable signal to the motor drive device (3), drives the motor (121) to run, drives the knife arm (13) to rotate, and accumulates and records the number of Hall signal pulses of the Hall sensor (1211); Step 4: When the cumulative value of the number of Hall signal pulses is equal to the number of pulses of the preset inserting tool position, the motor drive device (3) controls the motor (121) to brake, and feeds back the inserting tool position signal to the machine tool main control. After receiving the signal, the machine tool main control stops enabling output and restores the connection between the tool and the spindle; Step 5: the machine tool main control again sends an enable signal to the motor drive device (3), drives the motor (121) to run, drives the knife arm (13) to rotate, and accumulates and records the number of Hall signal pulses of the Hall sensor (1211); Step 6: When the tool arm (13) moves to the home position, the motor drive device (3) receives the origin signal transmitted by the origin sensor, controls the motor (121) to brake, and feeds back the home position signal to the machine tool main control, clearing the accumulated number of Hall signal pulses. After receiving the signal, the machine tool main control stops enabling the output, completing the entire tool changing action.

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