A spindle structure

Abstract

This invention relates to a spindle structure, including a mandrel, a sleeve, and a support bearing. A pull rod is disposed inside the mandrel, and a return disc spring is sleeved between the sleeve and the pull rod. A cutting tool is disposed at the front end of the pull rod. The sleeve is fixed to the machine tool housing. A fixed seat is disposed at the rear end of the mandrel. A first through hole is disposed at the center of the fixed seat. One end of the pull rod is inserted into the first through hole and can slide axially within the first through hole. A water cooling channel is disposed inside the pull rod. A plurality of tool-cutting holes are evenly opened on the fixed seat, and a tool-cutting rod is disposed in each tool-cutting hole. A tool-cutting ring is disposed next to the fixed seat. One end of the tool-cutting rod abuts against the pull rod, and the other end abuts against the tool-cutting ring. The switching between center water outlet and non-center water outlet is achieved by attaching and detaching a rotating water inlet connector at the end of the first through hole, so that the same rear end structure of the spindle can accommodate two functions. At the same time, the core structure and overall length of the spindle remain unchanged, the machine tool does not need to be heightened, and the center of gravity will not shift upward or the rigidity will decrease, thus ensuring the machining quality and machining accuracy.

Description

Technical Field

[0001] This invention relates to the field of machine tool spindle technology, and in particular to a spindle structure. Background Technology

[0002] The machine tool spindle is a core functional component of a CNC machining center, and its performance directly affects machining quality and efficiency. During machining, the cutting process generates a large amount of heat. If it is not cooled in time, it will seriously affect the tool life and workpiece machining accuracy. The center cooling function refers to the method of supplying coolant to the tool tip through the central channel of the spindle mandrel. Compared with external cooling methods, center cooling has advantages such as high cooling efficiency, precise cooling position, and high coolant utilization rate, and is widely used in various machining centers.

[0003] Currently, machining center spindles require two completely different spindle structures to be designed and manufactured, depending on whether a center water outlet function is needed: a non-center water outlet structure and a center water outlet structure. The rear end of the non-center water outlet structure is relatively simple, while the existing center water outlet structure requires the addition of complex adapter components and a separate tool changer drive mechanism at the tail end. This design leads to the following problems: First, the rear end structures of the two types of spindles are completely different, requiring separate stocking for each function during production, resulting in a wide variety of parts, high inventory costs, and complex production line adaptation. Second, the installation position of the pneumatic tool changer cylinder in the existing center water outlet structure differs significantly from that in the non-center water outlet structure, requiring the machine tool to be taller, shifting the center of gravity upwards, reducing the machine tool's strength and rigidity, thus affecting machining quality and accuracy. Furthermore, the structure is relatively bulky, increasing the manufacturing costs for machine tool manufacturers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a spindle structure that solves the problem of designing two different structures for center water outlet and non-center water outlet, thereby reducing the types of parts, reducing inventory and manufacturing costs.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: a spindle structure, including a mandrel, a sleeve sleeved on the mandrel, and a support bearing located between the mandrel and the sleeve. A pull rod is provided inside the mandrel, and the pull rod moves axially within the mandrel. A return disc spring is sleeved between the mandrel and the pull rod. A cutting tool is provided at the front end of the pull rod. The sleeve is fixed to the machine tool housing. A fixed seat is provided at the rear end of the mandrel. A first through hole is provided at the center of the fixed seat. One end of the pull rod is inserted into the first through hole and can slide axially within the first through hole. A water-cooling channel is provided inside the pull rod and communicates with the first through hole. A plurality of tool-cutting holes are evenly opened on the fixed seat. A tool-cutting rod is provided in each tool-cutting hole and can move axially within the tool-cutting hole. A tool-cutting ring is provided next to the fixed seat. One end of the tool-cutting rod abuts against the pull rod, and the other end abuts against the tool-cutting ring. Pushing the tool-cutting ring to apply force to the tool-cutting rod can cause the pull rod to move axially.

[0006] More specifically, a rotary water inlet connector is connected to the end of the first through hole away from the tie rod so that water can exit from the center of the main shaft structure.

[0007] More specifically, a connecting through hole is provided on the fixed base, and a connecting screw is provided in the connecting through hole. The connecting screw passes through the connecting through hole and is fixed to the cutting ring. The connecting screw can move axially within the connecting through hole. The diameter of the connecting through hole is larger than the diameter of the connecting screw body and smaller than the diameter of the connecting screw head.

[0008] More specifically, a return spring is fitted onto the body of the connecting screw, with one end of the return spring abutting against the fixing seat and the other end abutting against the head of the connecting screw.

[0009] More specifically, the side of the cutting ring closest to the mandrel extends toward the mandrel to form an annular guide plate, and a receiving space is formed between the guide plate and the cutting ring, into which the fixing seat and the mandrel can enter.

[0010] More specifically, the center of the fixed base extends away from the spindle to form an external protrusion, and the first through hole penetrates the external protrusion; a guide hole is provided at the corresponding position of the cutting ring, and the external protrusion passes through the guide hole.

[0011] More specifically, the pull rod includes a pull rod body and an annular baffle formed by the pull rod body extending radially, the reset disc spring abutting one side of the annular baffle, and the knife-cutting rod abutting the other side of the annular baffle.

[0012] More specifically, positioning grooves are provided on the annular baffle and the cutting ring, and the cutting rod is inserted into the positioning groove.

[0013] More specifically, a pulley assembly for connection with an external drive is provided at the rear end of the spindle.

[0014] More specifically, the pulley assembly includes a pulley sleeved on the outside of the mandrel, a tensioning seat, and a pressure cap. The tensioning seat is disposed between the pulley and the mandrel, and one end of the pressure cap abuts against the tensioning seat. The pressure cap and the pulley are connected by a locking screw, and the tensioning seat is tightened by adjusting the locking screw.

[0015] The beneficial effects of this invention are as follows: By setting a fixed seat at the rear end of the spindle, and setting a first through hole at the center of the fixed seat for the pull rod to pass through and slide axially, and opening a tool-cutting hole and setting a tool-cutting rod on the fixed seat, the tool-cutting and tool-changing function is realized in conjunction with the tool-cutting ring. At the same time, the first through hole of the fixed seat can be used as an interface for the coolant channel. By installing and removing the rotating water inlet connector at the end of the first through hole, the function of switching between center water outlet and non-center water outlet can be realized. This makes the same spindle rear end structure compatible with two functions, eliminating the need to design and produce different rear end structures for the two functions, greatly reducing the types of parts, reducing inventory costs and production line adaptation complexity. Meanwhile, the core structure and overall length of the spindle remain unchanged, the machine tool does not need to be heightened, and the center of gravity will not shift upward or the rigidity will decrease, thus ensuring the machining quality and machining accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the main shaft structure of the present invention;

[0017] Figure 2 yes Figure 1 Enlarged structural diagram of part A in the middle; Figure 3 This is a schematic diagram of the main shaft structure of the present invention (with the rotating water inlet connector assembled).

[0018] In the diagram: 10, mandrel; 20, sleeve; 30, support bearing; 40, pull rod; 41, water cooling channel; 42, annular baffle; 50, return disc spring; 60, fixed seat; 61, first through hole; 62, sealing ring; 63, external protrusion; 70, cutter bar; 80, cutter ring; 81, guide plate; 82, receiving space; 83, positioning groove; 90, connecting screw; 91, return spring; 100, pulley; 101, tensioning seat; 103, pressure cap; 104, locking screw; 200, rotating water inlet connector. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The direction of movement is also relative and is not limited to an absolute direction of movement. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figures 1-3 This application provides a spindle structure, including a spindle 10, a sleeve 20 sleeved on the spindle 10, and a support bearing 30 located between the spindle 10 and the sleeve 20. The sleeve 20 is fixed to the machine tool housing, providing support and positioning for the spindle 10. A pull rod 40 is provided inside the spindle 10, and the pull rod 40 can reciprocate in the axial direction within the spindle 10. A return disc spring 50 is sleeved between the spindle 10 and the pull rod 40, and the return disc spring 50 provides a return elastic force for the pull rod 40. A cutting tool is provided at the front end of the pull rod 40, and the clamping and loosening of the cutting tool is realized by the axial movement of the pull rod 40 to facilitate the replacement of the cutting tool.

[0023] A fixing seat 60 is provided at the rear end of the mandrel 10. The fixing seat 60 is fixedly connected to the mandrel 10 by screws and can rotate with the mandrel 10. A first through hole 61 is provided in the center of the fixing seat 60. One end of the pull rod 40 is inserted into the first through hole 61 and can slide axially within the first through hole 61. The two are sealed by a sealing ring 62. A water cooling channel 41 is provided in the pull rod 40 and communicates with the first through hole 61. The first through hole 61 serves as both a guide channel for the axial movement of the pull rod 40 and a flow channel for coolant. A plurality of tool-cutting holes are evenly provided on the fixed base 60, and a tool-cutting rod 70 is provided in each tool-cutting hole. The tool-cutting rod 70 can move axially within the tool-cutting hole. A tool-cutting ring 80 is provided next to the fixed base 60. One end of the tool-cutting rod 70 abuts against the pull rod 40, and the other end abuts against the tool-cutting ring 80. When a tool change is required, the tool-cutting ring 80 is pushed toward the fixed base 60. The tool-cutting ring 80 pushes the tool-cutting rod 70 to move axially within the tool-cutting hole. The tool-cutting rod 70 then pushes the pull rod 40 to move axially within the spindle 10, thereby releasing the tool at the front end of the pull rod 40 and realizing the tool change function.

[0024] The first through hole 61 of the fixed base 60 serves as the interface for the coolant channel. When the spindle structure does not require center water outlet, the end of the first through hole 61 away from the tie rod 40 remains open, and the spindle structure is a non-center water outlet structure. When the spindle structure requires center water outlet, a rotary water inlet connector 200 is connected to the end of the first through hole 61 away from the tie rod 40. The coolant enters the first through hole 61 through the rotary water inlet connector 200 and is then transported to the front end of the tool via the water cooling channel 41 inside the tie rod 40, thus achieving center water outlet. The rotary water inlet connector 200 is an external standard part, which is easy to install and remove. This allows the same spindle rear end structure to switch between center water outlet and non-center water outlet functions by simply installing and removing the rotary water inlet connector 200, making the same spindle rear end structure compatible with both functions without the need to design and manufacture different rear end structures for the two functions.

[0025] A sealing ring 62 is provided at the connection between the first through hole 61 and the rotary water inlet connector 200 to ensure the sealing performance in the center water outlet state and prevent coolant leakage.

[0026] A connecting through hole is also provided on the fixed base 60, and a connecting screw 90 is provided in the connecting through hole. After passing through the connecting through hole, the connecting screw 90 is fixed to the cutting ring 80, connecting the cutting ring 80 to the fixed base 60. The connecting screw 90 can move axially in the connecting through hole, allowing the cutting ring 80 to have a certain axial displacement relative to the fixed base 60, which can push the cutting rod 70 to move. The diameter of the connecting through hole is larger than the diameter of the body of the connecting screw 90 and smaller than the diameter of the head of the connecting screw 90. The head of the connecting screw 90 is restricted from passing through the connecting through hole, so it will not fall off the fixed base 60. At the same time, the body of the connecting screw 90 can slide freely in the connecting through hole without affecting the axial movement of the cutting ring 80.

[0027] A return spring 91 is fitted onto the body of the connecting screw 90. One end of the return spring 91 abuts against the fixing seat 60, and the other end abuts against the head of the connecting screw 90. When the cutter ring 80 is pushed and acts on the cutter rod 70 and the pull rod 40, the return spring 91 does not work. After the cutter replacement operation is completed, the external force of the cutter is removed, the cutter ring 80 is reset, and the return spring 91 is compressed. The elasticity of the return spring 91 ensures that the two ends of the cutter rod 70 are always in contact with the pull rod 40 and the cutter ring 80.

[0028] The cutting ring 80 extends from the side near the spindle 10 toward the spindle 10 to form an annular guide plate 81. The guide plate 81 and the cutting ring 80 form a receiving space 82. The fixed seat 60 and the rear end of the spindle 10 can enter the receiving space 82, so that the cutting ring 80 and the fixed seat 60 are tightly fitted. The guide plate 81 surrounds the outside of the fixed seat 60 and guides the movement of the cutting ring 80, ensuring that the cutting ring 80 moves smoothly in the axial direction and avoiding deflection.

[0029] The fixed base 60 extends outward from the center of the spindle 10 to form an external protrusion 63. The first through hole 61 passes through the external protrusion 63. The external protrusion 63 provides sufficient connection length and positioning reference for the installation of the rotary water inlet connector 200. A guide hole is provided at the corresponding position of the cutter ring 80, and the external protrusion 63 passes through the guide hole. The cutter ring 80 is further guided during axial movement through the cooperation of the guide hole and the external protrusion 63, ensuring the stable movement of the cutter ring 80 and preventing radial displacement. At the same time, the cooperation of the external protrusion 63 and the guide hole also plays a positioning role for the cutter ring 80.

[0030] The pull rod 40 includes a pull rod body and an annular baffle 42 formed by extending the pull rod body radially. The return disc spring 50 abuts against one side of the annular baffle 42, providing the pull rod 40 with a backward return elastic force. The cutter bar 70 abuts against the other side of the annular baffle 42. When the cutter bar 70 is pushed, the thrust is transmitted to the pull rod 40 through the annular baffle 42, causing the pull rod 40 to move forward against the elastic force of the return disc spring 50 and release the cutter. The annular baffle 42 ensures stable contact between the cutter bar 70 and the pull rod 40, uniform and reliable force transmission, and avoids local stress concentration.

[0031] Furthermore, positioning grooves 83 are provided on the annular baffle 42 and the cutting ring 80. The two ends of the cutting rod 70 are respectively inserted into the positioning grooves 83 on the annular baffle 42 and the cutting ring 80. The positioning grooves 83 play a role in positioning and constraining the cutting rod 70, preventing the cutting rod 70 from radially moving or falling off in the cutting hole, ensuring that the cutting rod 70 is always in reliable contact with the annular baffle 42 and the cutting ring 80, and ensuring the accuracy and stability of the cutting action.

[0032] A pulley assembly for connection with an external drive is also provided at the rear end of the mandrel 10; the pulley assembly includes a pulley 100 sleeved on the outside of the mandrel 10, a tensioning seat, and a pressure cover 103; the tensioning seat is disposed between the pulley 100 and the mandrel 10, one end of the pressure cover 103 abuts against the tensioning seat, and the pressure cover 103 is connected to the pulley 100 by a locking screw 104; tightening the locking screw 104 causes the pressure cover 103 to push the tensioning seat to expand and clamp the mandrel 10 in the radial direction, so that the external drive can drive the mandrel to rotate.

[0033] In the non-central water outlet state, the rotary water inlet connector 200 is not installed at the rear end of the first through hole 61 of the fixed base 60, and the spindle structure operates according to the standard non-central water outlet mode. When a tool change is required, the external tool-changing device pushes the tool-changing ring 80. The tool-changing ring 80 moves axially through the guide plate 81 and the external protrusion 63. The tool-changing ring 80 pushes the tool-changing rod 70 to move axially in the tool-changing hole. The tool-changing rod 70 pushes the annular baffle 42 of the pull rod 40, causing the pull rod 40 to move forward against the elastic force of the reset disc spring 50, releasing the tool. After the tool change is completed, the external tool-changing force is removed, the reset disc spring 50 resets, causing the pull rod 40 to reset. At the same time, the pull rod 40 pushes the tool-changing ring 80 to reset through the tool-changing rod 70. At this time, the reset spring 91 is compressed, and its elastic force acts on the connecting screw 90, so that both ends of the tool-changing rod 70 are always in contact with the annular baffle 42 and the tool-changing ring 80.

[0034] In the center water outlet state, a rotary water inlet connector 200 is installed at the rear end of the first through hole 61 of the fixed base 60. The coolant enters the first through hole 61 through the rotary water inlet connector 200 and is then transported to the front end of the tool through the water cooling channel 41 inside the pull rod 40 to achieve center water outlet cooling. The tool changing operation process is the same as in the non-center water outlet state.

[0035] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A spindle structure, comprising a spindle (10), a sleeve (20) sleeved on the spindle (10), and a support bearing (30) located between the spindle (10) and the sleeve (20), wherein a pull rod (40) is provided inside the spindle (10), the pull rod (40) moves axially within the spindle (10), a return disc spring (50) is sleeved between the spindle (10) and the pull rod (40), and a cutting tool is provided at the front end of the pull rod (40); the sleeve (20) is fixed to a machine tool housing, characterized in that, A fixed seat (60) is provided at the rear end of the mandrel (10). A first through hole (61) is provided in the center of the fixed seat (60). One end of the pull rod (40) is inserted into the first through hole and can slide axially in the first through hole (61). A water cooling channel (41) is provided in the pull rod (40) and the water cooling channel (41) is connected to the first through hole (61). Several punching holes are evenly opened on the fixed seat (60). A punching rod (70) is provided in each punching hole. The punching rod (70) can move axially in the punching hole. A punching ring (80) is provided next to the fixed seat (60). One end of the punching rod (70) abuts against the pull rod (40) and the other end abuts against the punching ring (80). Pushing the punching ring (80) can make the pull rod (40) move axially by applying force to the punching rod (70).

2. The spindle structure according to claim 1, characterized in that, The end of the first through hole (61) away from the pull rod (40) is connected to a rotary water inlet connector (200) so that water can be discharged from the center of the main shaft structure.

3. The spindle structure according to claim 1, characterized in that, A connecting through hole is provided on the fixed base (60), and a connecting screw (90) is provided in the connecting through hole. The connecting screw (90) passes through the connecting through hole and is fixed on the knife ring (80). The connecting screw (90) can move axially in the connecting through hole. The diameter of the connecting through hole is larger than the diameter of the body of the connecting screw (90) and smaller than the diameter of the head of the connecting screw (90).

4. The spindle structure according to claim 3, characterized in that, A return spring (91) is fitted on the body of the connecting screw (90). One end of the return spring (91) abuts against the fixing seat (60), and the other end abuts against the head of the connecting screw (90).

5. The spindle structure according to claim 1, characterized in that, The blade ring (80) extends toward the spindle (10) from the side near the spindle (10) to form a ring-shaped guide plate (81). A receiving space (82) is formed between the guide plate (81) and the blade ring (80). The fixing seat (60) and the spindle (10) can enter the receiving space (82).

6. The spindle structure according to claim 1, characterized in that, The center of the fixed base (60) extends away from the spindle (10) to form an external protrusion (63), and the first through hole (61) passes through the external protrusion (63); a guide hole is provided at the corresponding position of the cutting ring (80), and the external protrusion (63) passes through the guide hole.

7. The spindle structure according to claim 1, characterized in that, The pull rod (40) includes a pull rod body and an annular baffle (42) formed by the pull rod body extending radially. The reset disc spring (50) abuts against one side of the annular baffle (42), and the knife bar (70) abuts against the other side of the annular baffle (42).

8. The spindle structure according to claim 7, characterized in that, A positioning groove (83) is provided on the annular baffle (42) and the cutting ring (80), and the cutting rod (70) is inserted into the positioning groove (83).

9. The spindle structure according to claim 1, characterized in that, A pulley assembly for connection with an external drive is provided at the rear end of the spindle (10).

10. The spindle structure according to claim 9, characterized in that, The pulley assembly includes a pulley (100) sleeved on the outside of the spindle (10), a tensioning seat (101), and a pressure cap (103). The tensioning seat (102) is disposed between the pulley (100) and the spindle (10). One end of the pressure cap (103) abuts against the tensioning seat (102). The pressure cap (103) and the pulley (100) are connected by a locking screw (104). The tensioning seat is tightened by adjusting the locking screw (104).

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