Electric spindle structure of numerical control milling machine

Abstract

The invention belongs to the technical field of numerical control milling machines, and particularly relates to an electric spindle structure of a numerical control milling machine, which comprises a spindle body, the spindle body comprises a shell, a front bearing cover, a rear bearing cover and a rotor, and one end of the rotor is provided with an assembly head for clamping a cutter. The intercepting assembly comprises an intercepting cover installed outside the front bearing cover, the intercepting cover is in a vertical combination shape of a cylinder and an inverted circular truncated cone, and a plurality of flow guide grooves are distributed in the intercepting cover in an annular array mode. The second bearing is installed between the intercepting cover and the rotor, and the intercepting cover is rotationally connected with the rotor through the second bearing; the arc-shaped plate is fixedly mounted at the lower end of the intercepting cover, and the outer wall surface of the arc-shaped plate is C-shaped; by arranging the arc-shaped plate, long-strip-shaped cuttings can be guided back to the machining end and prevented from splashing to operators, the working safety is guaranteed, the problem that the cuttings are wound around the tool nose can be avoided, and the service life of the tool is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the field of CNC milling machines, and specifically relates to an electric spindle structure of a CNC milling machine. Background Art

[0002] A CNC milling machine controls the movement of each axis of the machine tool through pre-programmed digital instructions to achieve workpiece processing. It consists of a numerical control device, a machine tool body, and auxiliary devices, etc. Among them, the electric spindle is one of the core components of the machine tool body segment, which is responsible for machining operations such as cutting of the tool. When performing machining operations such as cutting, chips will be generated, and some chips will fly towards the operator, affecting safety.

[0003] A patent application with the publication number CN118808687B discloses a turning electric spindle, including a sleeve body, a stator member, and a rotor member. It further includes: a protective cover installed on the rotor member; a driving ring installed on the protective cover; a direction-changing transmission component installed between the driving ring and the rotor member; the protective cover is driven to rotate inwards relative to the rotor through the transmission component, so as to effectively capture and guide the chips generated during the turning process, prevent the chips from flying around, and ensure the safety of the working environment.

[0004] The above solution uses a protective cover that rotates reversely relative to the rotor to guide the chips back to the vicinity of the machining end to solve the problem of chip splashing. However, for some long strip-shaped chips, leading them back to the machining end may cause problems such as winding around the tool tip, scratching the machining surface, or chipping of the tool.

[0005] Therefore, the present invention provides an electric spindle structure of a CNC milling machine. Summary of the Invention

[0006] In order to make up for the deficiencies of the prior art and solve at least one of the technical problems proposed in the background art.

[0007] The technical solution adopted by the present invention to solve its technical problems is: an electric spindle structure of a CNC milling machine described in the present invention includes a spindle body, the spindle body includes a housing, a front bearing cover, a rear bearing cover, and a rotor. Two bearing one are respectively installed between the front bearing cover and the rear bearing cover and the rotor. One end of the rotor is provided with an assembly head for clamping the tool. It further includes an interception component for intercepting debris, and the interception component includes: an interception cover installed outside the front bearing cover, the interception cover has an upper and lower combined shape of a cylinder and an inverted frustum of a cone, and a plurality of diversion grooves are annularly and evenly distributed on the interception cover; a bearing two installed between the interception cover and the rotor, and the interception cover is rotatably connected to the rotor through the bearing two; an arc-shaped plate fixedly installed at the lower end of the interception cover, and the outer wall surface of the arc-shaped plate is in a C shape.

[0008] Preferably, the interception component further includes: an exhaust passage opened in the interception cover; a plurality of adsorption holes opened in the interception cover, the adsorption holes being communicated with the exhaust passage; a slip ring installed on the upper surface of the interception cover, the slip ring being communicated with the exhaust passage, the slip ring being rotatably connected to the interception cover, and the slip ring being fixedly installed on the housing.

[0009] Preferably, the aperture of the adsorption hole is smaller than the diameter of the exhaust passage, and a plurality of convex rods are slidably installed on the interception cover, and the adsorption holes are located within the moving range of the convex rods.

[0010] Preferably, the interception component further includes: a rotating rod for driving the convex rod to slide, the rotating rod being slidably connected to the convex rod, and the rotating rod being rotatably connected to the interception cover; a push rod for driving the rotating rod to rotate, the push rod being slidably connected to the interception cover; a circular ring rotatably installed on the push rod; a telescopic rod for driving the circular ring to move up and down, the circular ring being fixedly connected to the movable end of the telescopic rod; and a third spring installed between the push rod and the interception cover.

[0011] Preferably, the interception component further includes: a first gear fixedly installed on the rotor; a second gear rotatably installed on the front bearing cover, the first gear and the second gear being meshed; and a third gear for driving the interception cover to rotate, the third gear being meshed with the second gear.

[0012] Preferably, there are two interception covers. After the two interception covers are combined, the front bearing cover is covered inside. The interception cover is slidably inserted up and down with the slip ring. A chute is opened on the interception cover, and an annular plate is slidably installed in the chute. An insertion plate for limiting the annular plate is opened on the interception cover. The insertion plate is slidably connected up and down with the interception cover, and a first spring for resetting is installed between the insertion plate and the interception cover.

[0013] Preferably, it further includes: a plurality of insertion holes opened on the third gear; an insertion rod slidably installed on the inner wall of the interception cover, and the insertion rod is used to connect with the third gear through the insertion rod.

[0014] Preferably, it further includes: a fourth gear rotatably installed on the interception cover, the fourth gear being threadedly connected to the insertion rod; a fifth gear for driving the fourth gear to rotate, the fifth gear being rotatably installed on the interception cover; a connecting rod for driving the fifth gear to rotate, the connecting rod being rotatably installed on the interception cover, a trapezoidal block being slidably installed on the connecting rod, the trapezoidal block being located within the moving range of the connecting rod; and a second spring installed between the trapezoidal block and the connecting rod.

[0015] Preferably, a concave plate is fixedly installed outside the second bearing, and the intercepting cover is vertically movably inserted between the concave plate and the second bearing.

[0016] The beneficial effects of the present invention are as follows: 1. For the electric spindle structure of a CNC milling machine described in the present invention, by setting the arc-shaped plate, it can not only guide the long strip-shaped chips back to the processing end, prevent them from splashing towards the operator, ensure work safety, but also avoid the problem of debris entanglement on the tool tip, and ensure the service life of the tool.

[0017] 2. For the electric spindle structure of a CNC milling machine described in the present invention, by setting the adsorption holes and exhaust channels, according to the state of the processed chips, the adsorption mode is switched, optimizing the energy consumption control while ensuring the chip cleaning effect. It not only maintains the cleanliness of the production environment but also avoids energy waste caused by continuous suction. Cooperating with the convex rod, it can not only increase the friction of the intercepting cover but also block the adsorption holes to prevent impurities from entering the internal channel and dredge the possible remaining blockages, thus realizing the combination of dynamic adjustment of chip processing methods and self-cleaning functions. Through the displacement of the convex rod, two working modes of frictionally blocking large chips and negative pressure adsorbing small chips can be switched, which not only meets the cleaning requirements for different-sized chips but also effectively reduces the system maintenance frequency.

[0018] 3. For the electric spindle structure of a CNC milling machine described in the present invention, by setting structures such as the annular plate, the quick disassembly and connection of the intercepting cover are realized, which is convenient for quick maintenance when problems such as the decline in the chip guiding ability due to the smooth surface of the intercepting cover after long-term use and the blockage of the exhaust channel inside the intercepting cover occur, and it is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 is a perspective view of an embodiment of the present invention; Figure 2 is a sectional view of the intercepting cover of the present invention; Figure 3 is Figure 2 a partial enlarged view of part A in Figure 4 is a sectional view of the first gear, the third gear and the concave plate of the present invention; Figure 5 is a structural schematic diagram of the annular plate of the present invention; Figure 6 is a structural schematic diagram of the fifth gear of the present invention; Figure 7 is a structural schematic diagram of the trapezoidal block of the present invention; In the figure: 1. Housing; 2. Front bearing cover; 3. Rear bearing cover; 4. Rotor; 6. Intercepting assembly; 61. Intercepting cover; 62. Flow guiding groove; 63. Second bearing; 64. Arc plate; 65. Adsorption hole; 66. Exhaust passage; 67. Slip ring; 68. Convex rod; 69. Rotating rod; 610. Push rod; 611. Ring; 612. Telescopic rod; 613. First gear; 614. Second gear; 615. Third gear; 616. Third spring; 7. Chute; 8. Annular plate; 9. Insertion plate; 11. Insertion hole; 12. Insertion rod; 13. Fourth gear; 14. Fifth gear; 16. Connecting rod; 17. Trapezoidal block; 18. Second spring; 19. Concave plate. Detailed implementation manners

[0021] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0022] As Figures 1 - 7 shown, an electric spindle structure of a numerical control milling machine according to an embodiment of the present invention includes a spindle body, the spindle body includes a housing 1, a front bearing cover 2, a rear bearing cover 3 and a rotor 4. Two first bearings are respectively installed between the front bearing cover 2 and the rear bearing cover 3 and the rotor 4. One end of the rotor 4 is provided with a tool assembly head for clamping a tool. The structure further includes an intercepting assembly 6 for intercepting debris. The intercepting assembly 6 includes: an intercepting cover 61 installed outside the front bearing cover 2. The intercepting cover 61 has a combined shape of a cylinder and an inverted frustum of a cone, and a plurality of flow guiding grooves 62 are annularly and arrayedly distributed on the intercepting cover 61; a second bearing 63 installed between the intercepting cover 61 and the rotor 4. The intercepting cover 61 is rotatably connected to the rotor 4 through the second bearing 63; an arc plate 64 fixedly installed at the lower end of the intercepting cover 61. The outer wall surface of the arc plate 64 is in a C shape.

[0023] Specifically, in the prior art, the intercepting cover 61 that rotates reversely relative to the rotor 4 is used to guide the chips back to the vicinity of the machining end to prevent the chips from splashing. However, for some long chips, guiding them back to the machining end may cause problems such as winding around the tool tip, scratching the machining surface or chipping of the tool. The electric spindle body adopts an existing electric spindle structure with internal cooling and other structures. The electric spindle body further includes a stator. The stator is the stationary part of the motor and includes a stator core and a stator winding. When an electric current is passed through, a rotating magnetic field will be generated around the stator. The rotor 4 is the rotating part of the motor and is usually made of a conductive material. When the rotating magnetic field cuts the conductor of the rotor 4, an induced electromotive force and an induced current will be generated in the rotor 4, and then a torque will be generated to make the rotor 4 rotate. The rotation of the rotor 4 drives the tool on the tool assembly head to rotate synchronously, and thus machining operations such as cutting the workpiece can be realized. The surface of the interception cover 61 is a rough surface. During the machining process, the interception cover 61 is controlled to rotate counterclockwise relative to the rotor 4. The rotation of the interception cover 61 drives the arc plate 64 to rotate synchronously. The chips generated during machining have the same rotation direction as the rotor 4. Therefore, when the chips fly onto the surface of the interception cover 61, under the action of the frictional force of the interception cover 61, the chips first decelerate and then move downward in the diversion groove 62 of the interception cover 61 to the arc plate 64. Since the arc plate 64 rotates with the interception cover 61, a centrifugal force will be generated, causing the chips to move towards the machining end with the tool as the center. Limited by the shape of the outer wall surface of the arc plate 64, the chips diffuse outward at a small angle with the tool, which can not only lead the long strip-shaped chips back to the machining end to prevent them from splashing towards the operator and ensure work safety, but also avoid the problem of chips winding around the tool tip and ensure the service life of the tool.

[0024] As Figures 2 - 5 shown, the interception assembly 6 further includes: an exhaust passage 66 opened in the interception cover 61; a plurality of adsorption holes 65 opened on the interception cover 61, and the adsorption holes 65 are communicated with the exhaust passage 66; a slip ring 67 installed on the upper surface of the interception cover 61, the slip ring 67 is communicated with the exhaust passage 66, the slip ring 67 is rotatably connected to the interception cover 61, and the slip ring 67 is fixedly installed on the housing 1.

[0025] Specifically, the slip ring 67 is connected to an existing suction device with self-filtering (the start of this device is connected to the numerical control device of the machine tool. When the rotation speed of the tool is adjusted so that the chips are in a granular state, the device can be controlled to start). According to different processing requirements, when the rotation speed of the tool is low, the chips are larger. As the rotation speed of the tool increases, the chip size gradually decreases. When the chips are small enough to float in the air, the suction device is started, so that a suction force is generated at the adsorption holes 65 to suck away the granular chips, effectively reducing the dust pollution in the working area and improving the working environment of the operator. By switching the adsorption mode according to the chip state, while ensuring the chip cleaning effect, the energy consumption control is optimized, which not only maintains the cleanliness of the production environment but also avoids the energy waste caused by continuous suction.

[0026] As Figure 3 and Figure 5 shown, the aperture of the adsorption hole 65 is smaller than the diameter of the exhaust passage 66, and a plurality of convex rods 68 are slidably installed on the interception cover 61, and the adsorption holes 65 are located within the moving range of the convex rods 68.

[0027] Specifically, the number of adsorption holes 65 and convex rods 68 can be adjusted according to actual production requirements. When the debris is relatively large, a part of the end of the convex rod 68 passes through the adsorption hole 65 and is located in the diversion groove 62. The end of the convex rod 68 is made of a material with a relatively large coefficient of friction. At this time, the convex rod 68 can be used to increase the friction of the interception cover 61. When the size of the debris is relatively small, the convex rod 68 is controlled to slide into the interception cover 61. At this time, the adsorption hole 65 is unobstructed, and the debris can be sucked by the air extraction device. Since the aperture of the adsorption hole 65 is the smallest, if a blockage occurs, it will occur at the orifice. After the processing is completed, the convex rod 68 is controlled to move to block the adsorption hole 65 again, which can not only prevent impurities from entering the internal channel, but also use its mechanical action to dredge the possible remaining blockage, so as to realize the combination of dynamic adjustment of the debris treatment method and the self-cleaning function. This structure can switch between two working modes of friction blocking large debris and negative pressure adsorption of small debris through the displacement of the convex rod 68, which not only meets the cleaning requirements of debris of different sizes, but also effectively reduces the system maintenance frequency.

[0028] As Figures 3 - 5 shown, the interception component 6 further includes: a rotating rod 69 for driving the convex rod 68 to slide, the rotating rod 69 is slidably connected to the convex rod 68, and the rotating rod 69 is rotatably connected to the interception cover 61; a push rod 610 for driving the rotating rod 69 to rotate, the push rod 610 is slidably connected to the interception cover 61; a ring 611 rotatably mounted on the push rod 610; a telescopic rod 612 for driving the ring 611 to move up and down, the ring 611 is fixedly connected to the movable end of the telescopic rod 612; a third spring 616 mounted between the push rod 610 and the interception cover 61.

[0029] Specifically, a rotating ring is rotatably provided at the bottom of the ring 611, and the rotating ring is vertically movably inserted into the push rod 610. The push rod 610 is rotatably connected to the ring 611 through the rotating ring. The telescopic rod 612 adopts an electrically controlled structure (its start is connected to the numerical control device of the machine tool). When the size of the debris is relatively small, the electric telescopic rod 612 is controlled to start and extend downward, driving the ring 611 and the push rod 610 to move downward synchronously. The movement of the push rod 610 drives the rotating rod 69 to rotate, and the rotation of the rotating rod 69 drives the convex rod 68 to move into the interception cover 61, so that the adsorption hole 65 and the exhaust channel 66 can be opened. After the processing is completed, the telescopic rod 612 is controlled to reset, that is, the push rod 610 and the convex rod 68 can both be reset.

[0030] As Figure 4 shown, the interception component 6 further includes: a first gear 613 fixedly installed on the rotor 4; a second gear 614 rotatably installed on the front bearing cover 2, the first gear 613 and the second gear 614 are meshed and connected; a third gear 615 for driving the interception cover 61 to rotate, the third gear 615 is meshed and connected to the second gear 614.

[0031] Specifically, during processing, the rotor 4 rotates to drive the first gear 613 to rotate. The second gear 614 drives the third gear 615 to rotate reversely, and the third gear 615 drives the interception cover 61 to rotate in the same direction.

[0032] As Figures 5 - 6 shown, there are two interception covers 61. After the two interception covers 61 are combined, the front bearing cover 2 is covered inside. The interception cover 61 and the slip ring 67 are slidably inserted up and down. A chute 7 is opened on the interception cover 61. An annular plate 8 is slidably installed in the chute 7. An insertion plate 9 for limiting the annular plate 8 is opened on the interception cover 61. The insertion plate 9 is slidably connected up and down with the interception cover 61. A first spring for resetting is installed between the insertion plate 9 and the interception cover 61.

[0033] As Figures 2 - 6 shown, it further includes: a plurality of jacks 11 opened on the third gear 615; a plug rod 12 slidably installed on the inner wall of the interception cover 61, and the plug rod 12 is used to connect with the third gear 615 through the plug rod 12.

[0034] As Figures 5 - 7 shown, it further includes: a fourth gear 13 rotatably installed on the interception cover 61, and the fourth gear 13 is threadedly connected with the plug rod 12; a fifth gear 14 for driving the fourth gear 13 to rotate, and the fifth gear 14 is rotatably installed on the interception cover 61; a connecting rod 16 for driving the fifth gear 14 to rotate, and the connecting rod 16 is rotatably installed on the interception cover 61. A trapezoidal block 17 is slidably installed on the connecting rod 16, and the trapezoidal block 17 is within the moving range of the connecting rod 16; a second spring 18 installed between the trapezoidal block 17 and the connecting rod 16.

[0035] As Figure 4 shown, a concave plate 19 is fixedly installed outside the second bearing 63. The interception cover 61 is slidably inserted up and down between the concave plate 19 and the second bearing 63.

[0036] Specifically, during installation, the two interception covers 61 first slide upward, insert the slip ring 67 into the interior of the interception cover 61. While sliding upward, it can be connected to the second bearing 63 by inserting into the concave plate 19. After the two interception covers 61 are aligned, control the annular plate 8 to slide into the chute 7 of the other interception cover 61. Subsequently, the insertion plate 9 is inserted into the annular plate 8 under the action of the elastic force of the first spring to limit the annular plate 8, that is, the connection of the two interception covers 61 is achieved (a gasket is provided between the two interception covers 61 to achieve a sealed connection). During the movement of the annular plate 8, one end of the annular plate 8 can push the trapezoidal block 17 to rotate, and the trapezoidal block 17 pushes the connecting rod 16 and the fifth gear 14 to rotate. The rotation of the fifth gear 14 drives the rotation of the fourth gear 13. Since the fourth gear 13 is threadedly connected to the insertion rod 12, the insertion rod 12 slides relative to the interception cover 61 until the insertion rod 12 is inserted into the jack 11, and the connection between the interception cover 61 and the third gear 615 can be achieved through the insertion rod 12 and the jack 11. When disassembly is required, first slide the insertion plate 9 upward, and then turn the annular plate 8 back into their respective interception covers 61. During the movement of the annular plate 8, the other end of the annular plate 8 contacts the trapezoidal block 17, first pushes the trapezoidal block 17 to rotate, drives the fifth gear 14 and the fourth gear 13 to rotate, so that the insertion rod 12 is taken out of the jack 11, and the interception cover 61 and the third gear 615 are separated. Subsequently, the annular plate 8 continues to move, contacts the inclined surface of the trapezoidal block 17, and pushes the trapezoidal block 17 to contract into the connecting rod 16 to facilitate the passage of the annular plate 8. Then, slide the interception cover 61 downward to remove the interception cover 61; by setting structures such as the annular plate 8, the rapid disassembly and connection of the interception cover 61 can be achieved, which is convenient for quickly maintaining the interception cover 61 when problems such as the decline in the guiding ability of the smooth surface of the interception cover 61 for debris and the blockage of the exhaust passage 66 inside the interception cover 61 occur after long-term use, and it is easy to use.

[0037] Working principle: When an electric current is applied, a rotating magnetic field will be generated around the stator. The rotor 4 is the rotating part of the motor and is usually made of a conductive material. When the rotating magnetic field cuts the conductor of the rotor 4, an induced electromotive force and an induced current will be generated in the rotor 4, and then a torque will be generated to make the rotor 4 rotate. The rotation of the rotor 4 drives the large cutting tool on the assembly head to rotate synchronously, and the machining actions such as cutting the workpiece can be realized. During processing, the rotation of the rotor 4 drives the rotation of the first gear 613. The second gear 614 drives the third gear 615 to rotate in the reverse direction, and the third gear 615 drives the interception cover 61 to rotate in the same reverse direction. If the debris generated during processing is large-sized debris, when the debris splashes onto the surface of the interception cover 61, under the action of the frictional force of the interception cover 61, the debris first decelerates, and then moves downward in the diversion groove 62 of the interception cover 61 to the arc-shaped plate 64. Since the arc-shaped plate 64 rotates with the interception cover 61, a centrifugal force will be generated, causing the debris to move towards the processing end with the tool as the center. Restricted by the outer wall shape of the arc-shaped plate 64, the debris diffuses outward at a small angle with the tool. With the tool as the center, the debris diffuses outward at a small angle with the tool, which can not only lead the long strip-shaped chips back to the processing end, prevent them from splashing towards the operator, ensure work safety, but also avoid the problem of debris winding around the tool tip, ensuring the service life of the tool; If the debris generated during processing is small-sized debris, then control the electric telescopic rod 612 to start and extend downward, driving the ring 611 and the push rod 610 to move downward synchronously. The movement of the push rod 610 drives the rotating rod 69 to rotate, and the rotation of the rotating rod 69 drives the convex rod 68 to move towards the inside of the interception cover 61, then the adsorption hole 65 and the exhaust passage 66 can be opened. Start the suction device, so that suction is generated at the adsorption hole 65 to suck away the granular debris, effectively reducing the dust pollution in the working area and improving the working environment of the operator; When the processing is completed, control the telescopic rod 612 to reset, and the movement of the convex rod 68 blocks the adsorption hole 65 again, which can not only prevent impurities from entering the internal channel, but also use its mechanical action to dredge the possible remaining blockages, thus realizing the combination of the dynamic adjustment of the debris treatment method and the self-cleaning function.

[0038] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. The electric spindle structure of a numerically controlled milling machine, comprising a spindle body, the spindle body includes a housing (1), a front bearing cover (2), a rear bearing cover (3) and a rotor (4), two first bearings are respectively installed between the front bearing cover (2) and the rear bearing cover (3) and the rotor (4), and an assembly head for clamping a tool is provided at one end of the rotor (4), characterized in that, It further includes an interception component (6) for intercepting debris, and the interception component (6) includes: An interception cover (61) installed outside the front bearing cover (2). The interception cover (61) has a combined shape of a cylinder and an inverted frustum of a cone, and a number of diversion grooves (62) are annularly and arrayedly distributed on the interception cover (61); A second bearing (63) installed between the interception cover (61) and the rotor (4). The interception cover (61) is rotatably connected to the rotor (4) through the second bearing (63); An arc-shaped plate (64) fixedly installed at the lower end of the interception cover (61). The outer wall surface of the arc-shaped plate (64) is in a C shape.

2. The electric spindle structure of a CNC milling machine according to claim 1, characterized in that: The interception component (6) further includes: An exhaust passage (66) opened in the interception cover (61); A number of adsorption holes (65) opened on the interception cover (61). The adsorption holes (65) are communicated with the exhaust passage (66); A slip ring (67) installed on the upper surface of the interception cover (61). The slip ring (67) is communicated with the exhaust passage (66). The slip ring (67) is rotatably connected to the interception cover (61), and the slip ring (67) is fixedly installed on the housing (1).

3. The electric spindle structure of a CNC milling machine according to claim 2, characterized in that: The aperture of the adsorption hole (65) is smaller than the diameter of the exhaust passage (66). A number of convex rods (68) are slidably installed on the interception cover (61), and the adsorption holes (65) are located within the moving range of the convex rods (68).

4. The electric spindle structure of a CNC milling machine according to claim 3, characterized in that: The interception component (6) further includes: A rotating rod (69) for driving the convex rod (68) to slide. The rotating rod (69) is slidably connected to the convex rod (68), and the rotating rod (69) is rotatably connected to the interception cover (61); A push rod (610) for driving the rotating rod (69) to rotate. The push rod (610) is slidably connected to the interception cover (61); A circular ring (611) rotatably installed on the push rod (610); An expansion rod (612) for driving the circular ring (611) to move up and down. The circular ring (611) is fixedly connected to the movable end of the expansion rod (612); A third spring (616) installed between the push rod (610) and the interception cover (61).

5. The electric spindle structure of a CNC milling machine according to claim 4, characterized in that: The interception component (6) further includes: A first gear (613) fixedly installed on the rotor (4); A second gear (6 \alpha) rotatably installed on the front bearing cover (2). The first gear (613) and the second gear (614) are meshed and connected; A third gear (615) for driving the interception cover (61) to rotate. The third gear (615) is meshed and connected with the second gear (614).

6. The electric spindle structure of a numerically controlled milling machine according to claim 5, characterized in that: The interception cover (61) has two. After the two interception covers (61) are combined, the front bearing cover (2) is covered inside. The interception cover (61) is slidably inserted up and down with the slip ring (67). A chute (7) is provided on the interception cover (61), and an annular plate (8) is slidably installed in the chute (7). An insertion plate (9) for limiting the annular plate (8) is provided on the interception cover (61). The insertion plate (9) is slidably connected up and down with the interception cover (61). A first spring for resetting is installed between the insertion plate (9) and the interception cover (61).

7. The electric spindle structure of a CNC milling machine according to claim 6, characterized in that: Further included are: A plurality of insertion holes (11) provided in the third gear (615); An insertion rod (12) slidably installed on the inner wall of the interception cover (61), and the insertion rod (12) is used to connect with the third gear (615) through the insertion rod (12).

8. The electric spindle structure of a CNC milling machine according to claim 7, characterized in that: Further included are: A fourth gear (13) rotatably installed on the interception cover (61), and the fourth gear (13) is threadedly connected with the insertion rod (12); A fifth gear (14) for driving the fourth gear (13) to rotate, and the fifth gear (14) is rotatably installed on the interception cover (61); A connecting rod (16) for driving the fifth gear (14) to rotate, the connecting rod (16) is rotatably installed on the interception cover (61), a trapezoidal block (17) is slidably installed on the connecting rod (16), and the trapezoidal block (17) is located within the moving range of the connecting rod (16); A second spring (18) installed between the trapezoidal block (17) and the connecting rod (16).

9. The electric spindle structure of a numerically controlled milling machine according to claim 1, characterized in that: A concave plate (19) is fixedly installed on the outside of the second bearing (63), and the interception cover (61) is slidably inserted up and down with the second bearing (63) through the concave plate (19).

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