Tool changing device of automatic tool changing system of machining center and tool changing control method

Abstract

The invention discloses a tool changing device of an automatic tool changing system of a machining center and a tool changing control method, and relates to the technical field of motors and control of the motors. The device comprises an automatic tool changing device, an original point sensor and a special driver. The automatic tool changing device comprises a machine body, a driving device and a tool changing arm, the driving device is arranged above the machine body, and the tool changing arm can be driven to be rotationally arranged below the machine body; the original point sensor is fixedly mounted at an upper end cover of a rotating shaft of the tool changing arm through a fastening nut and a tooth buckle gasket, the original point sensor is triggered when the tool changing arm runs to a specific position, and the original point sensor generates an original point signal and transmits the original point signal to the special driver; and the special driver is used for driving the tool changing device to operate and recording the operation position of the tool changing arm by accumulating the pulse number of the Hall signal. The invention has the advantages of reliable performance, low failure rate, high efficiency, small volume, long service life and low maintenance cost.

Description

Technical Field

[0001] The present invention relates to the technical field of motors and control thereof, and in particular to a tool changing device and a tool changing control method of an automatic tool changing system of a machining center. 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: pulling out 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 traditional detection device uses a chain to link the signal wheel with the cam shaft in the tool arm deceleration mechanism, and installs multiple photoelectric sensors near the signal wheel to detect the tool arm position.

[0003] However, the above devices have the following disadvantages: 1. The power source adopts a three-phase asynchronous motor, which has low efficiency and large size. It also needs to be equipped with a special mechanical brake, and there are problems such as poor braking effect, easy wear of brake pads, and regular replacement. 2. The chain is at risk of loosening and breaking, causing errors in the detection of the knife arm position and even damaging other surrounding components. 3. 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 sensor are strict, resulting in a high price for the sensor. 4. The need for additional signal wheels and chains makes installation and debugging cumbersome, time-consuming and labor-intensive.

[0004] Therefore, how to provide a tool changing device and a tool changing control method for an automatic tool changing system of a machining center to solve the difficulties existing in the prior art is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of this, the present invention provides a tool changing device and a tool changing control method for an automatic tool changing system of a machining center, which have the advantages of reliable performance, low failure rate, high efficiency, small size, long life and low maintenance cost.

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

[0007] A tool changing device of an automatic tool changing system of a machining center, comprising an automatic tool changing device, an origin sensor and a special driver;

[0008] The automatic tool changing device comprises a machine body, a driving device and a tool changing arm: the driving device is arranged above the machine body, and the tool changing arm can be driven to rotate and is arranged below the machine body;

[0009] The origin sensor is fixedly installed on the upper end cover of the tool change arm shaft by a fastening nut and a toothed washer. When the tool change arm moves to a specific position, the origin sensor is triggered. The origin sensor generates an origin signal and transmits it to a dedicated driver.

[0010] A dedicated driver is used to drive the tool changer to operate and record the operating position of the tool changer arm by accumulating the number of pulses of the Hall signal.

[0011] Optionally, a transmission group and a cam shaft are provided in the body;

[0012] The driving device drives the cam shaft and the tool changing arm to move through the transmission group.

[0013] Optionally, a permanent magnet synchronous motor is arranged inside the driving device, and a Hall sensor is installed inside the permanent magnet synchronous motor to identify the position of the motor rotor and record the operating position of the tool changing arm.

[0014] Optionally, two buttons are provided on the dedicated drive, button one is used to enter the preset mode, and button two is used to record and set.

[0015] Optionally, a machine tool master control is also included, which is communicated with the dedicated driver and is used to generate an enable signal to control the start and stop of the dedicated driver.

[0016] A tool changing control method of an automatic tool changing system of a machining center, applied to a tool changing device of an automatic tool changing system of a machining center as described in any one of the above, comprises the following steps:

[0017] S1, detect the current flow and determine whether the system needs to change the tool according to the processing requirements;

[0018] S2. If the system needs to change the tool, the machine tool main control outputs an enable signal to the dedicated driver, and the dedicated driver drives the permanent magnet synchronous motor to run and accumulates the number of Hall signal pulses to obtain a cumulative value;

[0019] S3, when the accumulated value is consistent with the preset tool picking value, the dedicated driver controls the permanent magnet synchronous motor to stop running and determines the tool picking position, and sends the tool picking position signal to the machine tool main control, which stops enabling the output and disconnects the tool from the spindle;

[0020] S4, the machine tool main control outputs the enable signal again, the dedicated driver drives the permanent magnet synchronous motor to run and accumulates the number of Hall signal pulses;

[0021] S5. When the tool changing arm reaches the tool inserting position, the origin sensor is triggered and sends a signal to the dedicated driver. The dedicated driver controls the permanent magnet synchronous motor to stop running and determines the tool inserting position. The tool inserting position signal is sent to the machine tool main control. The machine tool main control stops enabling output and restores the connection between the tool and the spindle.

[0022] S6. The machine tool main control outputs the enable signal again, and the dedicated driver drives the permanent magnet synchronous motor to run and accumulate the number of Hall signal pulses. At the same time, it determines whether the accumulated value is consistent with the preset homing value. If so, the dedicated driver controls the permanent magnet synchronous motor to stop running and outputs the homing position signal to the machine tool main control to realize automatic tool change.

[0023] Optionally, in S2, if the system does not need to change the tool, the tool changing arm remains in the home position, and the dedicated driver outputs a home position signal to the machine tool main control.

[0024] It can be seen from the above technical solution that, compared with the prior art, the present invention provides a tool changing device and a tool changing control method for an automatic tool changing system of a machining center, which has the following beneficial effects: 1) The present invention adopts a permanent magnet synchronous motor to replace the traditional asynchronous motor to realize automatic tool changing of the machining center, which has the advantages of reliable performance, low failure rate, high efficiency, small size, long life and low maintenance cost; 2) The present invention replaces multiple sensors and signal wheels of the traditional detection device by adopting a single sensor as the origin signal, and the sensor is not affected by the size of the signal wheel, so the cost is more advantageous. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 A diagram of a tool changing device of an automatic tool changing system for a machining center disclosed by the present invention;

[0027] Figure 2 A half-section view of the origin sensor disclosed in the present invention;

[0028] Figure 3 It is a block diagram of the automatic tool changing system for a machining center disclosed in the present invention;

[0029] Figure 4 A flow chart of a tool changing control method of an automatic tool changing system for a machining center disclosed in the present invention;

[0030] Figure numerals: 1 is an automatic tool changing device, 11 is a machine body, 12 is a driving device, 121 is a permanent magnet synchronous motor, 13 is a tool changing arm, 2 is an origin sensor, and 3 is a dedicated driver. DETAILED DESCRIPTION

[0031] 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.

[0032] Reference Figure 1 As shown, the present invention discloses a tool changing device of an automatic tool changing system of a machining center, comprising an automatic tool changing device 1, an origin sensor 2 and a dedicated driver 3;

[0033] The automatic tool changing device 1 comprises a body 11, a driving device 12 and a tool changing arm 13: the driving device 12 is arranged above the body 11, and the tool changing arm 13 can be driven to rotate and is arranged below the body 11;

[0034] The origin sensor 2 is fixedly installed on the upper end cover of the rotating shaft of the tool changing arm 13 by a fastening nut and a toothed washer. When the tool changing arm 13 moves to a specific position, the origin sensor 2 is triggered. The origin sensor 2 generates an origin signal and transmits it to the dedicated driver 3.

[0035] A dedicated driver 3 is connected to the machine tool main control for driving the tool changing device to operate and record the operating position of the tool changing arm 13 by accumulating the number of pulses of the Hall signal;

[0036] The machine tool master control is used to generate an enable signal to control the start and stop of the dedicated driver 3.

[0037] Furthermore, a transmission group and a cam shaft are provided in the body 11;

[0038] The driving device 12 drives the cam shaft and the tool changing arm 13 to move through the transmission group.

[0039] Furthermore, a permanent magnet synchronous motor 121 is provided inside the driving device 12 , and a Hall sensor is installed inside the permanent magnet synchronous motor 121 for identifying the position of the motor rotor and recording the operating position of the tool changing arm 13 .

[0040] Further, see Figure 2 As shown, the origin sensor 2 is an inductive proximity switch sensor. When a metal object approaches an oscillating sensing head that can generate an electromagnetic field, eddy currents are generated inside the object. This eddy current reacts on the proximity switch, causing the oscillation ability of the proximity switch to decay and the internal circuit parameters to change, thereby identifying whether a metal object is approaching and controlling the on or off of the switch.

[0041] Furthermore, the dedicated driver 3 is mainly used to drive the permanent magnet synchronous motor, and at the same time record and feedback the running position of the tool change arm 13. The dedicated driver 3 performs phase switching according to the Hall state to drive the permanent magnet synchronous motor 121 to run. At the same time, the dedicated driver 3 records the running position of the motor by accumulating the Hall signal. When the tool change arm 13 runs to the tool insertion position, the origin sensor 2 sends a signal to the dedicated driver 3, and the dedicated driver 3 clears the pulse accumulation number to eliminate the error accumulation and ensure the accuracy of the running position of the tool change arm 13.

[0042] Furthermore, two buttons are provided on the dedicated driver 3, button 1 is used to enter the preset mode, and button 2 is used to record and set.

[0043] Further, see Figure 3 As shown, it also includes a machine tool main control, which is connected to the dedicated driver 3 for communication and is used to generate an enable signal to control the start and stop of the dedicated driver 3.

[0044] Specifically, the first input terminal of the dedicated driver 3 is connected to the origin sensor 2 , the second input terminal is connected to the Hall sensor, and the output terminal is connected to the permanent magnet synchronous motor 121 .

[0045] Specifically, the homing position and tool taking position of the tool changing arm 13 need to be preset. The function of button one is to enter the preset mode, and button two is to record and set. When entering the preset mode, the motor will maintain a lower speed. After the motor runs from the origin (insertion position) to the homing position, remove the enable signal, press the set key, and the driver will record the number of pulses at this position; resend the enable signal to make the motor work. When it runs to the tool taking position, remove the enable signal, press the set key, and the driver will record the number of pulses at this position. After completing the preset of the homing position and the tool taking position, you can remove button one, the driver will exit the preset mode, and the motor will return to normal speed.

[0046] Furthermore, the dedicated driver 3 has a power-off memory function, ensuring that even after encountering an emergency such as a power outage, the tool changing arm 13 can continue to perform the tool changing operation before the power outage, avoiding damage to the motor and mechanism caused by power outage shock and restart.

[0047] A tool changing control method for an automatic tool changing system of a machining center, applied to a tool changing device of an automatic tool changing system of a machining center as described above, referring to Figure 4 As shown, the following steps are included:

[0048] S1, detect the current flow and determine whether the system needs to change the tool according to the processing requirements;

[0049] S2. If the system needs to change the tool, the machine tool main control outputs an enable signal to the dedicated driver 3, and the dedicated driver 3 drives the permanent magnet synchronous motor 121 to run and accumulate the number of Hall signal pulses to obtain a cumulative value;

[0050] S3, when the accumulated value is consistent with the preset tool picking value, the dedicated driver 3 controls the permanent magnet synchronous motor 121 to stop running and determine the tool picking position, and sends the tool picking position signal to the machine tool main control, and the machine tool main control stops enabling output and disconnects the tool from the spindle;

[0051] S4, the machine tool main control outputs an enable signal again, and the dedicated driver 3 drives the permanent magnet synchronous motor 121 to run and accumulate the number of Hall signal pulses;

[0052] S5. When the tool changing arm 13 reaches the tool inserting position, the origin sensor 2 is triggered and sends a signal to the dedicated driver 3. The dedicated driver 3 controls the permanent magnet synchronous motor 121 to stop running and determine the tool inserting position, and sends the tool inserting position signal to the machine tool main control. The machine tool main control stops enabling output and restores the connection between the tool and the spindle.

[0053] S6. The machine tool main control outputs the enable signal again, and the dedicated driver 3 drives the permanent magnet synchronous motor 121 to run and accumulate the number of Hall signal pulses. At the same time, it is determined whether the accumulated value is consistent with the preset return value. If so, the dedicated driver 3 controls the permanent magnet synchronous motor 121 to stop running and outputs the return position signal to the machine tool main control to realize automatic tool change.

[0054] Furthermore, in S2, if the system does not need to change the tool, the tool changing arm 13 remains in the home position, and the dedicated driver 3 outputs a home position signal to the machine tool main control.

[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 tool changing device for an automatic tool changing system of a machining center, characterized in that: It comprises an automatic tool changing device (1), an origin sensor (2) and a dedicated driver (3); An automatic tool changing device (1) comprises a body (11), a driving device (12) and a tool changing arm (13): the driving device (12) is arranged above the body (11), and the tool changing arm (13) is arranged below the body (11) and can be driven to rotate; The origin sensor (2) is fixedly mounted on the upper end cover of the rotating shaft of the tool changing arm (13) by means of a fastening nut and a toothed washer. When the tool changing arm (13) moves to a specific position, the origin sensor (2) is triggered. The origin sensor (2) generates an origin signal and transmits it to a dedicated driver (3). A dedicated driver (3) is used to drive the tool changing device to operate and record the operating position of the tool changing arm (13) by accumulating the number of pulses of the Hall signal.

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

3. The tool changing device of the automatic tool changing system of a machining center according to claim 2, characterized in that: A permanent magnet synchronous motor (121) is arranged inside the driving device (12), and a Hall sensor is installed inside the permanent magnet synchronous motor (121) for identifying the position of the motor rotor and recording the operating position of the tool changing arm (13).

4. The tool changing device of the automatic tool changing system of a machining center according to claim 1, characterized in that: The dedicated driver (3) is provided with two buttons, button one is used to enter the preset mode, and button two is used to record and set.

5. The tool changing device of the automatic tool changing system of a machining center according to claim 1, characterized in that: It also includes a machine tool main control, which is in communication connection with the dedicated driver (3) and is used to generate an enable signal to control the start and stop of the dedicated driver (3).

6. A tool changing control method for an automatic tool changing system of a machining center, applied to a tool changing device of an automatic tool changing system of a machining center according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, detect the current flow and determine whether the system needs to change the tool according to the processing requirements; S2. If the system needs to change the tool, the machine tool main control outputs an enable signal to the dedicated driver (3), and the dedicated driver (3) drives the permanent magnet synchronous motor (121) to run and accumulate the number of Hall signal pulses to obtain a cumulative value; S3, when the accumulated value is consistent with the preset tool picking value, the dedicated driver (3) controls the permanent magnet synchronous motor (121) to stop running and determine the tool picking position, and sends the tool picking position signal to the machine tool main control, and the machine tool main control stops enabling output and disconnects the tool from the spindle; S4, the machine tool main control outputs an enable signal again, and the dedicated driver (3) drives the permanent magnet synchronous motor (121) to run and accumulate the number of Hall signal pulses; S5. When the tool changing arm (13) reaches the tool inserting position, the origin sensor (2) is triggered and sends a signal to the dedicated driver (3). The dedicated driver (3) controls the permanent magnet synchronous motor (121) to stop running and determines the tool inserting position. The tool inserting position signal is sent to the machine tool main control. The machine tool main control stops enabling output and restores the connection between the tool and the spindle. S6, the machine tool main control outputs an enable signal again, the dedicated driver (3) drives the permanent magnet synchronous motor (121) to run and accumulate the number of Hall signal pulses, and at the same time determines whether the accumulated value is consistent with the preset homing value. If so, the dedicated driver (3) controls the permanent magnet synchronous motor (121) to stop running and outputs a homing position signal to the machine tool main control, thereby realizing automatic tool change.

7. The tool changing control method of the automatic tool changing system of a machining center according to claim 6, characterized in that: In S2, if the system does not need to change the tool, the tool changing arm (13) remains in the home position, and the dedicated driver (3) outputs a home position signal to the machine tool main control.

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