Clamping device and machine tool

Abstract

The utility model relates to the technical field of workpiece clamping, and provides a clamping device and a machine tool, and the clamping device comprises a driving motor, a first encoder and a second encoder. Wherein the driving motor is provided with a motor output shaft, and the motor output shaft is rigidly connected with the pull rod; the first encoder is arranged on the driving motor and is suitable for monitoring the number of turns of rotation of the driving motor; the second encoder is arranged on the machine tool spindle and suitable for monitoring the number of rotation turns of the machine tool spindle. According to the clamping device provided by the utility model, the driving motor is rigidly connected with the pull rod, the first encoder is arranged at the driving motor, and the second encoder is arranged at the machine tool main shaft 1, so that the debugging difficulty of workpiece clamping is reduced, and the monitoring precision of the workpiece clamping state can be improved; and the clamping and loosening actions of the workpiece are controlled more accurately.

Description

Technical Field

[0001] This utility model relates to the field of workpiece clamping technology, specifically to a clamping device and a machine tool. Background Technology

[0002] When machining workpieces, they typically need to be clamped. Generally, the workpiece is fixed to the machine tool by a chuck and rotates at high speed driven by a motor. The cutting tool is controlled to carve on the workpiece surface, thus achieving the "tool feed" and completing the machining process. The chuck is a mechanical device on a machine tool used to clamp the workpiece. It utilizes the radial movement of movable jaws evenly distributed on the chuck body to clamp and position the workpiece. A chuck generally consists of three parts: the chuck body, the movable jaws, and the jaw drive motor assembly.

[0003] In direct-drive servo clamping systems, a single encoder is typically used to monitor the motor's status, such as the number of revolutions or torque, to enable real-time monitoring and adjustment of the workpiece clamping. For example, the encoder monitors the number of motor revolutions to ensure the workpiece is clamped. Alternatively, in dual-clutch servo clamping systems, multiple external sensors are used in conjunction with a magnetic ring on the rotary actuator to achieve axial displacement positioning.

[0004] However, in related workpiece clamping technologies, the clamping system requires many parts, is difficult to install and debug, and the motor is far from the machine tool spindle, resulting in low accuracy in monitoring the workpiece clamping status, making it difficult to accurately control the clamping and releasing actions of the workpiece. Utility Model Content

[0005] In view of the above-mentioned defects in the prior art, the present invention provides a clamping device to solve at least one of the above-mentioned technical defects in the prior art, so that when the device clamps the workpiece, it can reduce the difficulty of debugging, improve the monitoring accuracy of the workpiece clamping state, and improve the precise control of the workpiece clamping and releasing actions.

[0006] The second aspect of this utility model provides a machine tool.

[0007] To achieve the objective of this utility model, a clamping device is provided, comprising:

[0008] The drive motor is equipped with a motor output shaft, which is rigidly connected to the pull rod;

[0009] A first encoder is disposed on the drive motor and is adapted to monitor the number of rotations of the drive motor;

[0010] A second encoder is located on the machine tool spindle and is adapted to monitor the number of rotations of the machine tool spindle.

[0011] Preferably, the clamping device includes a main housing, which forms an accommodating space.

[0012] The clamping device further includes an electric pull rod input shaft, which is rotatably disposed within the accommodating space along its own central axis.

[0013] The first end of the electric pull rod input shaft is connected to the motor output shaft, and the second end of the electric pull rod input shaft is rigidly connected to the pull rod.

[0014] Preferably, the clamping device is further provided with a bearing, the bearing is disposed in the accommodating space, and the electric pull rod input shaft is connected to the bearing.

[0015] Preferably, the clamping device is further provided with an electromagnetic clutch, which is located in the accommodating space and matched with the input shaft of the electric pull rod.

[0016] Preferably, the clamping device is further provided with a speed reducer, the first end of which is connected to the second end of the electric pull rod input shaft, and the second end of which is rigidly connected to the pull rod.

[0017] Preferably, the speed ratio of the reducer is 20, 25 or 30.

[0018] Preferably, the clamping device further includes a matching lead screw and a lead screw nut.

[0019] The lead screw is connected to the reducer, and the lead screw nut is connected to the pull rod.

[0020] Preferably, the lead of the lead screw and the lead screw nut is 5mm, 8mm or 10mm.

[0021] The second aspect of this utility model provides a machine tool, including the above-mentioned clamping device and machine tool body.

[0022] The clamping device is located on the machine tool body.

[0023] Preferably, the machine tool further includes a tie rod and a machine tool spindle.

[0024] The pull rod passes through the machine tool spindle, and the clamping device is connected to the pull rod.

[0025] The beneficial effects of this utility model are as follows: The clamping device provided by this utility model, by rigidly connecting the drive motor and the pull rod, and setting a first encoder at the drive motor and a second encoder at the machine tool spindle, reduces the difficulty of adjusting the workpiece clamping, and improves the monitoring accuracy of the workpiece clamping state, making the clamping and releasing action control of the workpiece more precise.

[0026] The machine tool provided by this utility model, having included the aforementioned clamping device, inevitably possesses all the advantages of that device. That is, the machine tool can reduce the difficulty of adjusting workpiece clamping, and can improve the monitoring accuracy of the workpiece clamping state, making the clamping and releasing actions of the workpiece more precise. Attached Figure Description

[0027] The above and other objects, features, and advantages of this utility model will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this application.

[0028] Figure 1 A schematic diagram of the overall structure of the clamping device provided in the embodiment of this utility model;

[0029] Figure 2 A schematic diagram showing the connection relationship between the first encoder, the second encoder, and the clamping device is provided for embodiments of this utility model.

[0030] In the picture:

[0031] 1. Machine tool spindle; 2. Main housing; 21. Accommodation space;

[0032] 100. Drive motor; 110. Motor output shaft; 111. Bearing;

[0033] 200. Pull rod;

[0034] 300. First encoder;

[0035] 400. Second encoder;

[0036] 500. Electric pull rod input shaft; 510. Electromagnetic clutch;

[0037] 600. Gearbox;

[0038] 700, lead screw;

[0039] 800, Screw nut. Detailed Implementation

[0040] To facilitate understanding of this utility model, a more comprehensive description of this utility model will be given below with reference to the accompanying drawings.

[0041] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0042] 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 applies. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] The following is combined with Figures 1 to 2 The embodiments of this utility model will be described below. It should be understood that the following description is merely an illustrative embodiment of this utility model and does not constitute any limitation on this utility model.

[0044] Combination Figures 1 to 2 The present invention provides a clamping device, which is installed on a machine tool spindle 1. A pull rod 200 is provided on the machine tool spindle 1. The clamping device includes a drive motor 100, a first encoder 300 and a second encoder 400.

[0045] The drive motor 100 is equipped with a motor output shaft 110, which is rigidly connected to the pull rod 200. The drive motor 100 transmits driving force to the pull rod 200 through the motor output shaft 110, so that the pull rod 200 can move along its own axial direction. This reduces the number of components that couple the drive motor 100 and the pull rod 200 (e.g., reducing the number of electromagnetic clutches), lowers the cost of accessories, simplifies the structure of the clamping device, and makes the adjustment of the workpiece clamping easier.

[0046] The first encoder 300 is installed on the drive motor 100 and can monitor the rotation of the drive motor 100.

[0047] The second encoder 400 is installed on the machine tool spindle 1 and can monitor the number of rotations of the machine tool spindle 1.

[0048] The rotation value of the drive motor 100 monitored by the first encoder 300 is recorded as A1, and the rotation value of the machine tool spindle 1 monitored by the second encoder 400 is recorded as B1. Both are transmitted to the controller. After processing, the rotation state of the drive motor 100 and the machine tool spindle 1 can be precisely controlled, thereby improving the clamping accuracy of the clamping device.

[0049] It is understood that the clamping device provided in the embodiments of this utility model reduces the difficulty of workpiece clamping and debugging by rigidly connecting the drive motor 100 and the pull rod 200, setting a first encoder 300 at the drive motor 100 and a second encoder 400 at the machine tool spindle 1, and can improve the monitoring accuracy of the workpiece clamping state, making the clamping and releasing action control of the workpiece more precise.

[0050] Specifically, in some embodiments of this utility model, the clamping device is provided with a main housing 2, and the main housing 2 forms an accommodating space 21.

[0051] The clamping device also includes an electric pull rod input shaft 500, which is rotatably disposed in the accommodating space 21 along its own central axis, that is, the electric pull rod input shaft 500 can be rotatably disposed in the main housing 2.

[0052] The first end of the electric pull rod input shaft 500 is connected to the motor output shaft 110, and the second end of the electric pull rod input shaft 500 is rigidly connected to the pull rod 200, which makes the structure of the clamping device simpler, the manufacturing cost lower, and also allows the driving force of the drive motor 100 to be better transmitted to the pull rod 200.

[0053] In some embodiments of this utility model, the clamping device is further provided with a bearing 111, which is disposed in the accommodating space 21. The electric pull rod input shaft 500 is connected to the bearing 111, which can support the electric pull rod input shaft 500, reduce the coefficient of friction during the movement of the electric pull rod input shaft 500, and make the movement of the electric pull rod input shaft 500 more flexible.

[0054] In some embodiments of this utility model, the clamping device is also provided with an electromagnetic clutch 510. The electromagnetic clutch 510 is provided in the accommodating space 21 and is matched with the electric pull rod input shaft 500. The electromagnetic clutch 510 can make the clamping device have a braking system, making it more convenient to control the clamping device to clamp the workpiece.

[0055] Of course, in some embodiments of this utility model, the clamping device is further provided with a reducer 600. The first end of the reducer 600 is connected to the second end of the electric pull rod input shaft 500, and the second end of the reducer 600 is rigidly connected to the pull rod 200. The speed ratio of the reducer 600 can be 20, 25, or 30. For example, in this embodiment, the speed ratio of the reducer 600 is 25. This allows for more flexible control of the clamping speed of the clamping device.

[0056] In addition, in some embodiments of this utility model, the clamping device further includes a matching lead screw 700 and a lead screw nut 800.

[0057] The lead screw 700 is connected to the reducer 600, and the lead screw nut 800 is connected to the tie rod 200.

[0058] The lead of the lead screw 700 and lead screw nut 800 can be 5mm, 8mm, or 10mm; for example, in this embodiment, the lead is 8mm. This ensures that the drive of the drive motor 100 is converted into the axial power of the pull rod 200.

[0059] Combination Figures 1 to 2The clamping device provided in this embodiment of the invention can feed back the rotation number A1 of the drive motor 100 and the rotation number B1 of the machine tool spindle 1 to the controller. The controller can control the rotation state of the drive motor 100 and the machine tool spindle 1 based on the rotation number A1. That is, the controller can control the drive motor 100 to rotate forward, reverse, or stop based on the rotation number A1 of the drive motor 100, and the controller can also control the machine tool spindle 1 to rotate forward, reverse, or stop based on the rotation number B1 of the machine tool spindle 1. This makes the clamping or releasing control of the workpiece more precise, ensuring that the workpiece is clamped more firmly and does not loosen during processing, and can be completely released after processing is completed.

[0060] The first encoder 300 can also monitor the speed and angle parameters of the drive motor 100 to improve the monitoring accuracy of the drive motor 100 status.

[0061] The second encoder 400 can also monitor the rotation angle position of the machine tool spindle 1 to improve the monitoring accuracy of the machine tool spindle 1 status.

[0062] When the machine tool is waiting for or loading materials, the clamping device can release the workpiece. At this time, neither the drive motor 100 nor the machine tool spindle 1 is running. The first encoder 300 only records the initial position value of the drive motor 100, while the second encoder 400 only records the initial position value of the machine tool spindle 1.

[0063] After the machine tool completes the loading, the clamping device clamps the workpiece, and the machine tool spindle 1 remains stationary. At this time, the second encoder 400 only records the initial position value of the machine tool spindle 1, while the drive motor 100 starts to rotate actively to drive the pull rod 200 to clamp the workpiece. The first encoder 300 records the number of rotations of the drive motor 100 (which can be denoted as A1) and feeds A1 back to the controller. The controller controls the start and stop of the drive motor according to the value of A1.

[0064] When the machine tool processes the workpiece, the clamping device clamps the workpiece, and the machine tool spindle 1 starts to rotate. At this time, the second encoder 400 records the number of rotations of the machine tool spindle 1 (which can be recorded as B1), and the first encoder 300 continues to record the number of rotations of the drive motor 100 (at this time, the number of rotations of the drive motor 100 is recorded as A2).

[0065] After the machine tool finishes processing the workpiece, the clamping device releases the workpiece. The controller controls the drive motor 100 to rotate in the opposite direction based on the number of revolutions that the drive motor 100 has rotated as monitored by the first encoder 300 (i.e., the sum of the values ​​A1 and A2 mentioned above) and the number of revolutions that the machine tool spindle 1 has rotated as monitored by the second encoder 400 (i.e., the value B1 mentioned above), so that the workpiece is released.

[0066] Furthermore, due to the presence of other connecting parts (e.g., lead screws, reducers, brakes, etc.) between the first encoder 300 and the second encoder 400, the values ​​A2 and B2 are usually inconsistent, and the number of revolutions recorded by A2 is typically smaller than that recorded by B2. Therefore, when the workpiece is released after the machine tool has finished machining it, the controller controls the drive motor 100 to rotate in the reverse direction by a number of revolutions R. When the drive motor 100 receives the release revolution number R from the controller, rotating in the reverse direction by the corresponding number of revolutions R can release the workpiece. R can be calculated using the following formula:

[0067] R = A1 + A2 - B1 + t, where t is a supplementary constant that can be manually input during debugging to compensate for mechanical errors, depending on the clamping device.

[0068] For example, when t is +0.5, the R value will automatically increase by 0.5 turns, meaning it will loosen by 0.5 turns more; when t is -0.5, the R value will automatically decrease by 0.5 turns, meaning it will loosen by 0.5 turns less.

[0069] Combination Figures 1 to 2 An embodiment of this utility model also provides a machine tool, which includes the above-described clamping device and machine tool body.

[0070] The clamping device is located on the machine tool body. The machine tool also includes a drawbar 200 and a machine tool spindle 1. The drawbar 200 passes through the machine tool spindle 1, and the clamping device is connected to the drawbar 200.

[0071] It is understood that the machine tool provided by the embodiments of this utility model, since it includes the above-mentioned clamping device, necessarily possesses all the advantages of that clamping device. That is, the machine tool can also reduce the difficulty of adjusting workpiece clamping, and can improve the monitoring accuracy of workpiece clamping status, making the clamping and releasing action control of workpiece more precise.

[0072] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of 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.

[0073] In the description of this specification, the use of terms such as "preferred embodiment," "another embodiment," "some embodiments," "other embodiments," or "specific example," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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.

[0074] 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. A chucking device provided to a machine tool spindle provided with a drawbar, characterized in that, The clamping device comprises: a driving motor, provided with a motor output shaft, the motor output shaft being in a rigid connection with the pull rod; a first encoder, provided on the driving motor, adapted to monitor the rotation number of the driving motor; a second encoder, provided on the machine tool spindle, adapted to monitor the rotation number of the machine tool spindle.

2. The clamping device of claim 1, wherein The clamping device is provided with a main housing, the main housing being formed with a containing space, the clamping device further comprises an electric pull rod input shaft, the electric pull rod input shaft being rotatably arranged along its central axis in the containing space, the first end of the electric pull rod input shaft is connected with the motor output shaft, and the second end of the electric pull rod input shaft is in a rigid connection with the pull rod.

3. The clamping device of claim 2, wherein The clamping device is further provided with a bearing, the bearing being arranged in the containing space, and the electric pull rod input shaft is connected with the bearing.

4. The clamping device of claim 3, wherein The clamping device is further provided with an electromagnetic clutch, the electromagnetic clutch being arranged in the containing space and being matched with the electric pull rod input shaft.

5. The clamping device of claim 4, wherein The clamping device is further provided with a speed reducer, the first end of the speed reducer being connected with the second end of the electric pull rod input shaft, and the second end of the speed reducer being in a rigid connection with the pull rod.

6. The clamping device of claim 5, wherein The speed ratio of the speed reducer is 20, 25 or 30.

7. The clamping device of claim 6, wherein The clamping device further comprises a lead screw and a lead screw nut matched with each other, the lead screw is connected with the speed reducer, and the lead screw nut is connected with the pull rod.

8. The clamping device of claim 7, wherein The lead of the lead screw and the lead screw nut matched with each other is 5mm, 8mm or 10mm.

9. A machine tool, characterized by The clamping device and a machine tool body according to any one of claims 1 to 8 are comprised, the clamping device is arranged on the machine tool body.

10. A machine tool as claimed in claim 9, characterised in that, The machine tool further comprises a pull rod and a machine tool spindle, the pull rod is arranged through the machine tool spindle, and the clamping device is connected with the pull rod.

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