Electric clamping system with stroke control function

Abstract

The utility model relates to the technical field of electric clamping systems, in particular to an electric clamping system with stroke control, which comprises a controller, an encoder, a driving motor and a rotary force transmission device, the rotary force transmission device is further provided with a lead screw main body and a lead screw nut, and the lead screw nut is sleeved on the periphery of the lead screw main body and matched with the lead screw main body. The lead screw nut is driven to axially move when the lead screw body rotates, the rotating speed of the lead screw body is matched with the axial movement of the lead screw nut, the output end of the driving motor is in driving connection with the lead screw body, the encoder is used for reading the rotating speed of the lead screw body, and the encoder is in communication connection with the controller and sends a rotating signal to the controller. And the controller controls the axial movement of the lead screw nut according to the rotation signal. The encoder is arranged to read the rotating speed of the lead screw body so as to limit the stroke, namely the starting position and the maximum stroke position, of the lead screw body, an electromagnetic inductor does not need to be arranged for soft limiting, and the starting position and the maximum stroke position can be limited respectively.

Description

TECHNICAL FIELD

[0001] The utility model belongs to electric clamping system technical field, concretely relates to a kind of electric clamping system with stroke control BACKGROUND

[0002] In the existing electric pull rod structure (electric clamping system), the stroke size of the clamp used for clamping workpiece is determined by the effective stroke of screw rod in electric pull rod, to prevent screw rod from running overstroke, soft limiting is set in the existing structure by electromagnetic inductor, to limit starting position and maximum stroke position respectively.In addition, due to fast processing rhythm, high-speed reciprocating action of screw rod in electric pull rod is more frequent, in this process, if screw rod runs overstroke, light will appear that ball in screw rod falls, heavy screw nut will be twisted off and break screw rod. CONTENT OF UTILITY MODEL

[0003] In view of the deficiency of prior art, the utility model provides a kind of electric clamping system with stroke control, electric clamping system with stroke control includes controller, encoder, drive motor and rotary force transmitter, the rotary force transmitter is further provided with screw rod main body and screw nut, the screw nut is sleeved on the outer periphery of the screw rod main body and is matched with it, the screw rod main body rotates and drives screw nut to move axially, and the rotating speed of the screw rod main body is adapted to the axial movement of screw nut, the output end of the drive motor is drivingly connected with the screw rod main body, the encoder is used to read the rotating signal of the drive motor and / or the screw rod main body, the encoder is connected with the controller in communication, and the rotating signal is sent to the controller, and the controller controls the axial movement of screw nut according to the rotating signal.

[0004] Preferably, the drive motor can be forward and reverse, and the drive motor drives the screw rod main body to rotate forward and reverse;

[0005] The rotary force transmitter further includes electromagnetic clutch, the electromagnetic clutch is connected with the controller in communication, the electromagnetic clutch has locking state and release state to the screw rod main body, when being in release state, the screw rod main body can rotate freely to drive the screw nut to move axially along the screw rod main body, when being in locking state, the screw rod main body cannot rotate compared with the electromagnetic clutch, so that the screw nut is stationary in axial direction relative to the screw rod main body.

[0006] Preferably, the encoder is arranged on the drive motor, for reading the rotating speed of the drive motor, the output end of the drive motor is output shaft, the input end of the screw rod main body is drivingly connected with the output shaft through input shaft, the electromagnetic clutch is sleeved on the outer periphery of the input shaft, and the electromagnetic clutch includes magnetic base and clutch piece;

[0007] The rotary force transmitter further comprises a protective shell, the screw rod body and the screw rod nut are arranged in the protective shell, the magnetic base is fixed in the protective shell, the clutch sleeve is arranged on the outer periphery of the input shaft, the clutch is connected or separated by energizing or de-energizing the magnetic base, the screw rod body is fixed relative to the protective shell when the magnetic base and the clutch are connected, and the screw rod body is freely rotated relative to the protective shell when the magnetic base and the clutch are separated.

[0008] Preferably, the driving motor is an inner rotor brushless motor, and the output shaft is arranged at a rotor output end of the driving motor and connected to the input shaft through a steel coupling.

[0009] Preferably, the electric clamping system with stroke control further comprises a power supply control system configured to receive a power supply input current, the power supply control system is connected to the controller, and the controller controls the power supply control system and the driving motor to be electrically connected or disconnected.

[0010] Preferably, the rotary force transmitter further comprises a speed reducer arranged between the input shaft and the screw rod body, an input end of the speed reducer is drivingly connected to the input shaft, and an output end of the speed reducer is connected to an input end of the screw rod body; the speed ratio of the speed reducer is a fixed value, and the controller controls the axial movement distance of the screw rod nut through the speed ratio of the speed reducer and the rotating speed of the driving motor.

[0011] Preferably, an output end of the driving motor is an output shaft, an input end of the screw rod body is drivingly connected to the output shaft through an input shaft, the encoder is arranged on the screw rod body or the input shaft, the encoder is configured to read the rotating speed of the screw rod body or the input shaft, and the controller controls the axial movement distance of the screw rod nut according to the rotating signal of the screw rod body or the input shaft.

[0012] Preferably, the encoder is arranged on the driving motor, an output end of the output shaft of the driving motor is connected to a steel coupling, one end of the steel coupling away from the output shaft is connected to an input shaft, the input shaft is sleeved with an electromagnetic clutch, the other end of the input shaft is connected to an input end of a speed reducer, and the speed reducer is connected to the screw rod body. BRIEF DESCRIPTION OF DRAWINGS

[0013] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The embodiments of the present application, illustrated in the drawings, are not meant to be limiting and but rather are for explanation. The emphasis is on the principles of the present application.

[0014] Figure 1 The schematic diagram of the electric clamping system provided for the embodiment is shown in the figure.

[0015] Figure 2 The schematic diagram of the electric clamping system provided for the embodiment is shown in the figure.

[0016] The figure shows the schematic diagram of the electric clamping system provided for the embodiment. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings.

[0018] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element and integrated as a whole, or a middle element can exist at the same time. The terms "mount", "one end", "the other end" and similar expressions used herein are only for illustrative purposes.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0020] Please refer to Figure 1 and Figure 2 The present application provides an electric clamping system with stroke control, which comprises a controller, an encoder 1, a driving motor 2 and a rotary force transmitter. The rotary force transmitter is further provided with a screw body 8 and a screw nut 9. The screw nut 9 is sleeved on the outer periphery of the screw body 8 and is matched with it. When the screw body 8 rotates, it drives the screw nut 9 to move axially, and the rotation speed of the screw body 8 is matched with the axial movement of the screw nut 9. The driving motor 2 is drivingly connected to the screw body 8. The encoder 1 is used to read the rotation signal of the driving motor 2 and / or the screw body 8. The encoder 1 is in communication connection with the controller and sends the rotation signal to the controller. The controller controls the axial movement of the screw nut 9 according to the rotation signal.

[0021] In the above further structure, the driving motor 2 is drivingly connected to the input shaft 5, the input shaft 5 is drivingly connected to the speed reducer 7, and the speed reducer 7 is drivingly connected to the screw body 8. The driving motor 2 drives the input shaft 5, the speed reducer 7 and the screw body 8 in turn.

[0022] This invention uses an encoder 1 to read the rotation signal of the lead screw body 8 to limit the stroke of the lead screw body 8, namely the starting position and the maximum stroke position, without the need for an electromagnetic sensor for soft limiting. It can limit the starting position and the maximum stroke position respectively. On the other hand, it can adapt to machine tool processing with a fast processing cycle and avoid the lead screw running over the stroke, which may result in the ball bearings inside the lead screw falling off or the lead screw nut 9 coming off and breaking the lead screw.

[0023] In a preferred embodiment, the drive motor 2 can rotate forward and reverse, and the drive motor 2 drives the lead screw body 8 to rotate forward and reverse. The rotary force transmitter also includes an electromagnetic clutch 6, which is communicatively connected to the controller. The electromagnetic clutch has a locked state and an unlocked state for the lead screw body 8. When it is in the unlocked state, the lead screw body 8 can rotate freely and drive the lead screw nut 9 to move back and forth along the axial direction of the lead screw body 8. When it is in the locked state, the lead screw body 8 cannot rotate relative to the electromagnetic clutch, so that the lead screw nut 9 is stationary relative to the lead screw body 8 in the axial direction.

[0024] With the above settings and the cooperation of the electromagnetic clutch 6, the controller can accurately control the axial distance of the lead screw nut 9.

[0025] In a preferred embodiment, encoder 1 is mounted on drive motor 2 to read the rotational speed of drive motor 2. The output end of drive motor 2 is output shaft 3. The input end of lead screw body 8 is drivenly connected to output shaft 3 via input shaft 5. Electromagnetic clutch 6 is sleeved on the outer periphery of input shaft 5 and includes a magnetic base and a clutch component. The rotary power transmitter also includes a protective housing. Lead screw body 8 and lead screw nut 9 are disposed inside the protective housing. The magnetic base is fixed inside the protective housing, and the clutch component is sleeved on the outer periphery of input shaft 5. The clutch component is connected or disconnected by energizing or de-energizing the magnetic base. When the magnetic base and clutch component are connected, lead screw body 8 is fixed relative to the protective housing. When the magnetic base and clutch component are disconnected, lead screw body 8 rotates freely relative to the protective housing. The above configuration facilitates installation and integrated design of the rotary power transmitter.

[0026] In a preferred embodiment, the drive motor 2 is an internal rotor brushless motor, and the output shaft 3 is located at the rotor output end of the drive motor 2. The output shaft 3 is connected to the input shaft 5 via a rigid coupling 4. Since the speed of the lead screw body 8 is read by the encoder 1 to limit the stroke of the lead screw body 8, i.e., the starting position and the maximum stroke position, there is no need to set up an electromagnetic sensor for soft limiting, reducing the need for electromagnetic sensor operation. At this time, the setting of the rigid coupling 4 facilitates the connection and installation of the output shaft 3 and the input shaft 5, and the output shaft 3 and the input shaft 5 rotate synchronously, which facilitates precise control.

[0027] In a preferred embodiment, the electric clamping system with stroke control further includes a power control system. The power control system is used to receive the input current from the power supply. The power control system is connected to the controller signal. The controller controls the power control system and the drive motor 2 to achieve electrical connection or control the two to disconnect from electrical connection.

[0028] In existing drive motor 2 structures, the power supply lines are directly connected to the stator or rotor coils of the drive motor 2. When the external power supply is on, the current passes through the coils and is converted into magnetic force, thereby converting electrical energy into rotational mechanical energy to drive other mechanical components. However, when the drive motor 2 is not powered and rotates passively as a whole, the power cables may become entangled and damaged. If only the rotor of the drive motor 2 rotates while the stator does not rotate, the current generated by the drive motor 2 will flow in reverse into the motor's power circuit, causing circuit damage. For the structure and working principle of the rotary force transmitter of this utility model, please refer to [reference needed]. Figure 2 This invention provides a novel power supply system for the drive motor 2, which controls the power control system and the drive motor 2 to achieve electrical connection or disconnection through the aforementioned power control system and controller. When the workpiece is fully clamped, the machine tool spindle or the motor's driver and encoder send a signal to notify the motor power control system to disconnect the motor power supply and motor connection. When the workpiece is finished and needs to be released, a signal is sent again to notify the motor power control system to reconnect the closed circuit, and this action command is repeated. The advantage of this system is that it can flexibly control the power supply of the drive motor 2. When the electric pull rod needs the drive motor 2 to rotate normally to clamp or release the workpiece, the system is closed and powered on. The drive motor 2 rotates normally to drive the electric pull rod to clamp or release the workpiece. When the workpiece is being processed, the electric pull rod will rotate at high speed with the machine tool spindle. Therefore, after the workpiece is clamped, the machine tool will immediately give a signal to notify the power supply system of the drive motor 2 to disconnect the power supply connection of the drive motor 2 so as not to constitute current backflow. Therefore, under the premise that the drive motor 2 is rigidly connected to the electric pull rod, even if the electric pull rod rotates at high speed with the machine tool spindle, the current generated by the passive rotation of the drive motor 2 will not flow back into the circuit system and damage the power supply circuit.

[0029] In a preferred embodiment, the rotary power transmitter further includes a reducer 7, which is disposed between the input shaft 5 and the lead screw body 8. The input end of the reducer 7 is drivenly connected to the input shaft 5, and the output end of the reducer 7 is connected to the input end of the lead screw body 8. The speed ratio of the reducer 7 is a fixed value, and the controller controls the axial movement distance of the lead screw nut 9 through the speed ratio of the reducer 7 and the rotational speed of the drive motor 2.

[0030] The speed ratio of a speed reducer, also known as the transmission ratio, refers to the ratio between the input speed and the output speed of the speed reducer. The reduction ratio is represented by the symbol "i" and indicates the ratio of the instantaneous input speed to the output speed in the reduction mechanism. For example, if the input speed is 1500 r / min and the output speed is 25 r / min, then the reduction ratio is 60:1.

[0031] The rotation signal can be either the rotation speed or the number of rotations. The axial movement distance can be calculated by the rotation speed and time. When the number of rotations is used to represent the axial movement distance, the maximum axial movement stroke L can be preset to correspond to the number of rotations. For example, if the maximum stroke is 20 rotations, then 5, 10, and 15 rotations represent 0.25L, 0.5L, and 0.75L respectively. Each time control is applied, only 20 rotations in both the forward and reverse directions are read before pausing the rotation, thus achieving one opening and closing action. More specifically as follows:

[0032] With the motor rigidly connected directly to the rotary power transmitter, the encoder built into the drive motor is used to read the motor's speed to determine the number of revolutions the leadscrew has made, thus calculating the translational distance of the leadscrew nut. Taking a leadscrew with a 20-speed reducer and a 10mm lead as an example, the calculation is as follows: when the motor speed is 2000 RPM, the leadcrew nut's translational speed is 8.33 mm / s. The axial movement distance can then be calculated based on the rotation time. Alternatively, the number of revolutions can be used for calculation. The specific algorithm is as follows: the reducer output speed is 2000 / 20 = 50 RPM, or 50 / 60 = 0.833 rpm. Since the leadscrew is directly connected to the reducer output, the translational speed of the leadscrew nut is 0.833 * 10 = 8.33 mm / s. Alternatively, it can be calculated that the leadscrew nut translates 1 / 20 * 10 = 0.5 mm per revolution of the motor.

[0033] Through the drive connection of the drive motor 2, output shaft 3, input shaft 5, reducer 7 and lead screw body 8, and with the speed ratio of the reducer 7 being a fixed value, the axial movement distance of the lead screw nut 9 can be controlled by the speed ratio of the reducer 7 and the speed of the drive motor 2.

[0034] The setting of reducer 7 improves the torque output of drive motor 2. At the same time, since reducer 7 can reduce the speed at the output end proportionally according to the speed ratio, the speed read when reading the speed at the output end of reducer 7 and the lead screw body 8 is more accurate.

[0035] In a preferred embodiment, the output end of the drive motor 2 is the output shaft 3, and the input end of the lead screw body 8 is drivenly connected to the output shaft 3 through the input shaft 5. The encoder 1 is set on the lead screw body 8 or on the input shaft 5. The encoder 1 is used to read the rotation speed of the lead screw body 8 or the rotation speed of the input shaft 5. The controller controls the axial movement distance of the lead screw nut 9 according to the rotation signal of the lead screw body 8 or the input shaft 5.

[0036] In this structure, encoder 1 is a sensor, which is a conventional technology. The sensor's scale (induction code disk) is fixedly mounted on the input shaft 5 or the lead screw body 8. The sensor (reader) is fixedly mounted on a part that does not rotate with the lead screw body 8 or on the housing. During the rotation inside the rotary power transmitter, the sensor (reader) calculates the distance the lead screw nut 9 has translated by reading the scale (induction code disk), thereby determining whether the lead screw has exceeded its travel. By placing encoder 1 inside the rotary power transmitter, ordinary commercially available motors can be used directly without modification. Furthermore, placing encoder 1 inside the rotary power transmitter facilitates integrated design and improves the versatility of the rotary power transmitter.

[0037] In a preferred embodiment, the encoder 1 is mounted on the drive motor 2. The output end of the drive motor 2 is the output shaft 3. The output end of the output shaft 3 is connected to the rigid coupling 4. The end of the rigid coupling 4 away from the output shaft 3 is connected to the input shaft 5. An electromagnetic clutch 6 is mounted on the input shaft 5. The other end of the input shaft 5 is connected to the input end of the reducer 7. The reducer 7 is connected to the lead screw body 8.

[0038] When a workpiece needs to be clamped or released, the electromagnetic clutch 6 is in the disengaged state. The drive motor 2 rotates forward or reverse, sequentially driving the output shaft 3, rigid coupling 4, input end of reducer 7, output end of reducer 7, and lead screw body 8 to rotate in sequence, causing the lead screw nut 9 to move axially, thereby driving one end of the machine tool spindle to clamp or release the workpiece. Once the workpiece is clamped in place, the electromagnetic clutch 6 is immediately controlled to lock the input shaft 5 or lead screw body 8 and prevent them from rotating. When the input shaft 5 or lead screw body 8 needs to be rotated again, the electromagnetic clutch 6 is set to the disengaged state. The encoder 1 reads the rotational speed of the lead screw body 8 to limit the stroke of the lead screw body 8, i.e., the starting position and the maximum stroke position, without the need for a soft limiter using an electromagnetic sensor. The starting position and the maximum stroke position are limited respectively. For more specific structures and working principles of this utility model electric clamping system, its electromagnetic clutch, reducer, lead screw body, and lead screw nut, please refer to the patent application literature of the same applicant, entitled "A Rotary Force Transmitter and Machine Tool", disclosed as CN118060573A.

[0039] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0041] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An electric clamping system with stroke control, characterized in that, An electric clamping system with stroke control includes a controller, an encoder, a drive motor, and a rotary force transmitter. The rotary force transmitter also includes a lead screw body and a lead screw nut. The lead screw nut is sleeved on the outer circumference of the lead screw body and is matched with it. When the lead screw body rotates, it drives the lead screw nut to move axially, and the rotational speed of the lead screw body is adapted to the axial movement of the lead screw nut. The output end of the drive motor is driven and connected to the lead screw body. The encoder is used to read the rotation signal of the drive motor and / or the lead screw body. The encoder is communicatively connected to the controller and sends the rotation signal to the controller. The controller controls the axial movement of the lead screw nut according to the rotation signal.

2. The electric clamping system with stroke control as described in claim 1, characterized in that, The drive motor can rotate forward and reverse, and the drive motor drives the lead screw body to rotate forward and reverse. The rotary force transmitter also includes an electromagnetic clutch, which is communicatively connected to the controller. The electromagnetic clutch has a locked state and a released state for the lead screw body. When it is in the released state, the lead screw body can rotate freely, driving the lead screw nut to move back and forth along the axial direction of the lead screw body. When it is in the locked state, the lead screw body cannot rotate relative to the electromagnetic clutch, so that the lead screw nut is stationary relative to the lead screw body in the axial direction.

3. The electric clamping system with stroke control as described in claim 2, characterized in that, The encoder is mounted on the drive motor and is used to read the rotational speed of the drive motor. The output end of the drive motor is an output shaft. The input end of the lead screw body is drivenly connected to the output shaft through the input shaft. The electromagnetic clutch is sleeved on the outer circumference of the input shaft. The electromagnetic clutch includes a magnetic base and a clutch element. The rotary power transmitter also includes a protective housing. The lead screw body and lead screw nut are disposed inside the protective housing. The magnetic base is fixed inside the protective housing. The clutch is sleeved on the outer circumference of the input shaft. The clutch is connected or disconnected by energizing or de-energizing the magnetic base. When the magnetic base and the clutch are connected, the lead screw body is fixed relative to the protective housing. When the magnetic base and the clutch are disconnected, the lead screw body rotates freely relative to the protective housing.

4. The electric clamping system with stroke control as described in claim 3, characterized in that, The drive motor is an internal rotor brushless motor, and the output shaft is located at the rotor output end of the drive motor. The output shaft is connected to the input shaft through a rigid coupling.

5. The electric clamping system with stroke control as described in claim 4, characterized in that, The electric clamping system with stroke control also includes a power control system, which receives the input current from the power supply. The power control system is signal-connected to the controller, and the controller controls the power control system and the drive motor to achieve electrical connection or disconnect the electrical connection.

6. The electric clamping system with stroke control as described in claim 3, characterized in that, The rotary power transmitter also includes a speed reducer, which is disposed between the input shaft and the lead screw body. The input end of the speed reducer is drivenly connected to the input shaft, and the output end of the speed reducer is connected to the input end of the lead screw body. The speed ratio of the speed reducer is a fixed value, and the controller controls the axial movement distance of the lead screw nut by the speed ratio of the speed reducer and the rotational speed of the drive motor.

7. The electric clamping system with stroke control as described in claim 1, characterized in that, The output end of the drive motor is an output shaft, and the input end of the lead screw body is driven to the output shaft through an input shaft. The encoder is set on the lead screw body or on the input shaft. The encoder is used to read the rotational speed of the lead screw body or the rotational speed of the input shaft. The controller controls the axial movement distance of the lead screw nut according to the rotational number signal of the lead screw body or the input shaft.

8. The electric clamping system with stroke control as described in claim 1, characterized in that, The encoder is mounted on the drive motor. The output end of the drive motor is an output shaft. The output end of the output shaft is connected to a rigid coupling. The end of the rigid coupling away from the output shaft is connected to an input shaft. An electromagnetic clutch is fitted over the input shaft. The other end of the input shaft is connected to the input end of a speed reducer. The speed reducer is connected to the lead screw body.

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