Automatic tool changing device of metal processing machine tool

Abstract

The utility model relates to the technical field of machine tool machining, and discloses an automatic tool changing device of a metal machining machine tool, which comprises a tool disc, a plurality of tool clamping devices are arranged on the tool disc along the circumferential direction of the tool disc, a tool disc cover is arranged on the front side cover of the tool disc, and each tool clamping device comprises a mounting seat with an L-shaped structure. Clamping arm mounting grooves are formed in the two sides of the bottom of the mounting base respectively, clamping arm rotating shafts are rotationally connected to the tops and the bottoms of the clamping arm mounting grooves, clamping arms are fixedly connected to the clamping arm rotating shafts, the clamping arms are located in the clamping arm mounting grooves, an elastic piece of a U-shaped structure is arranged between the rear ends of the two clamping arms, and a reset spring is arranged between the two ends of the elastic piece. The clamping arm rotating shaft is fixedly connected with gears of a fan-shaped structure at the bottom of the mounting base, and the two gears are meshed with each other. Through the arrangement of the elastic piece and the gear, the opening and closing synchronism and the clamping degree of the two clamping arms are enhanced.

Description

Technical Field

[0001] This utility model relates to the field of machine tool processing technology, and in particular to an automatic tool changer for a metal processing machine tool. Background Technology

[0002] As core equipment for machining complex and precision parts, the clamping stability of the tool changing mechanism in CNC machine tools directly affects machining accuracy and production efficiency. To meet the demands of multi-variety, automated tool changing, various tool clamping devices have emerged in the existing technology. Among them, the structure that provides clamping force through springs is widely used due to its simple structure and low cost. For example, Chinese patent CN208178462U discloses a tool turret device for CNC machine tools. Its tool clamping device includes a connecting plate, a left tool holder, a right tool holder, and a tool head clamping spring. The left and right tool holders are directly connected by a single tool head clamping spring, utilizing the spring's elasticity to clamp and open / close the tool. It offers advantages such as multi-tool head configuration and automated tool changing, improving tool changing linkage to some extent. However, this tool clamping device directly connects the two tool holders via the tool head clamping spring, relying on the spring's own elasticity for centering. This is prone to uneven spring elasticity and installation deviations, leading to asynchronous opening and closing of the two tool holders, tool eccentricity (especially for slender tools), vibration during machining, and resulting in out-of-tolerance dimensional accuracy of the parts. Furthermore, if only a single spring provides the clamping force, the spring is prone to fatigue and deformation after long-term use, resulting in a decrease in clamping force, which in turn makes the tool prone to slight movement during machining. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide an automatic tool changer for metalworking machine tools to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model adopts the following technical solution:

[0005] An automatic tool changer for a metalworking machine tool includes a tool disc with multiple tool clamping devices arranged circumferentially thereon. A tool disc cover is provided on the front side of the tool disc. Each tool clamping device includes an L-shaped mounting base. Clamping arm mounting grooves are respectively provided on both sides of the bottom of the mounting base. A clamping arm rotating shaft is rotatably connected to the top and bottom of the clamping arm mounting grooves. A clamping arm is fixed to the clamping arm rotating shaft and is located within the clamping arm mounting groove. A U-shaped spring is provided between the rear ends of two clamping arms, and a return spring is provided between the two ends of the spring. A sector-shaped gear is fixedly connected to the clamping arm rotating shaft at the bottom of the mounting base, and the two gears mesh with each other.

[0006] Furthermore, the spring includes a U-shaped spring body, the horizontal arm of the spring body is provided with a fixing hole, and the vertical arm of the spring body is provided with a locking hole; a sleeve is provided at the end of the vertical arm, and the two ends of the return spring are provided inside the sleeve.

[0007] Furthermore, the connection between the vertical arm and the horizontal arm of the spring is configured as an arc-shaped structure.

[0008] Furthermore, the surfaces of the vertical and / or horizontal arms of the spring are provided with crisscrossing reinforcing ribs.

[0009] Furthermore, the included angle at the connection point of the crisscrossing reinforcing ribs is set to be an arc shape.

[0010] Furthermore, a reinforcing arm is provided on the upper back of the mounting base, and the reinforcing arm is provided with a through hole for the spring clip to pass through.

[0011] Furthermore, the end of the clamping arm is provided with a roller mounting groove, and a roller shaft is fixed at the top and bottom of the roller mounting groove. A roller is rotatably connected to the roller shaft, and the roller is located in the roller mounting groove. The roller is coaxial with the roller shaft.

[0012] Furthermore, a tool number sticker is affixed to the outer wall of the tool disc cover corresponding to the tool clamping device. Beneficial effects

[0013] Compared with the prior art, the present invention has at least the following advantages:

[0014] 1. The dual elastic structure of the U-shaped spring and the return spring works together to bear the clamping force, with the spring assisting the return spring in sharing the load; and the reinforcing rib with guide arc treatment on the spring and the arc transition structure between the vertical and horizontal arms reduce stress concentration, improve fatigue strength, reduce the decay rate of clamping force, and eliminate the risk of tool micro-movement or falling off caused by long-term high-frequency tool changes.

[0015] 2. The clamping arms and gears are fixed on the clamping arm shaft, so that the opening and closing of the clamping arms and the rotation of the gears are completely synchronized. The meshing of the two gears makes the opening and closing angles and speeds of the two clamping arms completely consistent, so that no axial offset will occur when clamping the tool, reducing the vibration generated during processing, thereby improving the machining accuracy of the parts. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the connection structure between the tool clamping device and the tool disc of this utility model.

[0018] Figure 3 This is a schematic diagram of the tool clamping device of this utility model.

[0019] Figure 4 This is a bottom view of the tool clamping device of this utility model.

[0020] Figure 5 This is a schematic diagram of one embodiment of the spring clip of this utility model.

[0021] Figure 6 This is a schematic diagram of another embodiment of the spring sheet of this utility model.

[0022] The diagram is labeled as follows: 1-Tool disc cover; 2-Tool number sticker; 3-Tool; 4-Tool clamping device; 40-Mounting base; 400-Strip fixing hole; 401-Clamping arm mounting slot; 41-Clamping arm shaft; 42-Clamping arm; 420-Roller mounting slot; 43-Roller; 44-Spring; 440-Spring body; 441-Fixing hole; 442-Sleeve; 443-Locking hole; 444-Reinforcing rib; 45-Reinforcing arm; 450-Through hole; 46-Return spring; 47-Gear; 48-Mounting post; 480-Screw hole; 49-Roller shaft; 5-Tool disc. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, a detailed description is provided below in conjunction with the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0024] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0025] 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 invention pertains. The terminology used herein 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.

[0026] See Figures 1-6This embodiment provides an automatic tool changer for a metalworking machine tool, including a tool disc 5. The tool disc 5 has multiple tool clamping devices 4 arranged circumferentially for holding tools. A tool disc cover 1 is provided on the front side of the tool disc 5, and tool number stickers 2 are affixed to the outer wall of the tool disc cover corresponding to the tool clamping devices. Each tool clamping device 4 includes an L-shaped mounting base 40. A reinforcing arm 45 is provided on the upper back of the mounting base 40, and a strip-shaped fixing hole 400 is provided on the top of the mounting base 40. The strip-shaped fixing hole 400 passes through the reinforcing arm 45. A screw passes through the strip-shaped fixing hole 400 and locks into a pre-set threaded hole on the tool disc 5, thus mounting the tool clamping device 4 onto the tool disc 5. The mounting base 40 has clamp arm mounting grooves 401 on both sides of its bottom. The top and bottom of the clamp arm mounting grooves 401 are rotatably connected to clamp arm shafts 41. The clamp arm shafts 41 are fixedly connected to clamp arms 42. The clamp arms 42 are located in the clamp arm mounting grooves 401. A U-shaped spring piece 44 is provided between the rear ends of the two left and right clamp arms 42. The reinforcing arm 45 is provided with a through hole 450 for the spring piece to pass through.

[0027] The spring piece 44 includes a U-shaped spring piece body 440, which includes a horizontal arm and two vertical arms located at both ends of the horizontal arm; the surfaces of the vertical arms and / or the horizontal arms of the spring piece are provided with interlaced reinforcing ribs 444. The included angle at the connection between the interlaced reinforcing ribs 444 is set as an arc-shaped structure.

[0028] The connection between the vertical and horizontal arms of the spring piece 44 is designed with an arc shape. The horizontal arm of the spring piece body 440 has a fixing hole 441. A screw passes through the fixing hole 441 and is threadedly connected to a fixing screw hole on the mounting base 40, locking the spring piece body 440 to the back of the mounting base 40 and preventing the spring piece 44 from shifting. The vertical arm of the spring piece body 440 has a locking hole 443. A screw passes through the locking hole 443 and is threadedly connected to a locking screw hole on the inner side of the end of the clamping arm 42. A sleeve 442 is provided on the inner side of the end of the vertical arm, and a return spring 46 is provided between the two ends of the spring piece 44, with both ends of the return spring 46 located inside the sleeve 442. The clamping arm shaft 41 extends to the bottom of the mounting base 40, and a sector-shaped gear 47 is fixedly connected to the bottom of the mounting base 40. The two gears 47 are symmetrically arranged and mesh with each other. When the clamping arm 42 rotates, the rotation of one gear 47 will synchronously drive the other gear to rotate in the opposite direction through the meshing relationship, forcing the opening and closing angles and speeds of the two clamping arms 42 to be completely consistent. It should be noted that a limit plate is provided at the end of the clamping arm shaft to limit the position of the gear 47 and prevent it from falling off.

[0029] The end of the clamping arm 42 is provided with a roller mounting groove 420. A roller shaft 49 is fixed to the top and bottom of the roller mounting groove 420. A roller 43 is rotatably connected to the roller shaft 49. The roller 43 is located within the roller mounting groove 420 and is coaxial with the roller shaft 49. When changing tools, the rotational friction between the tool 3 and the roller greatly reduces frictional resistance. The roller 43, located at the end of the clamping arm 42, guides the tool 3 in and out of the clamping arm 42.

[0030] The bottom of the mounting base 40 has a protruding mounting post 48, which is higher than the top surface of the gear 47. The mounting post 48 has a screw hole 480, and a through hole corresponding to the mounting post 48 is made on the cutter head cover 1. A screw passes through the through hole and locks into the screw hole 480 of the mounting post 48, thus fixing the cutter head cover 1 to the mounting base 40. A space is formed between the mounting base 40 and the cutter head cover 1 for the gear 47 to mesh and rotate, ensuring that the opening and closing of the clamping arm 42 is not affected.

[0031] Working principle: When the tool clamping device clamps the tool, the return spring 46 provides axial force through the sleeve 442 at the end of the vertical arm of the spring piece 44, exerting force outward on the clamping arm. At the same time, the structural elasticity of the U-shaped spring piece 44 itself supports the clamping arm 42. The spring piece 44 and the return spring 46 work together to keep the left and right clamping arms 42 in a closed state, tightly clamping the tool 3. At this time, the two meshing sector gears 47 are in the initial meshing position. The rigid meshing relationship forces the opening and closing angles of the two clamping arms 42 to be consistent, avoiding clamping eccentricity caused by uneven elasticity of the spring piece 44 or the return spring 46. When the machine tool needs to change tools, external force is applied to the roller 43 and the clamping arm 42, driving the clamping arm 42 to rotate outward with the clamping arm shaft 41. As the clamping arm shaft 41 rotates, it immediately drives the gear 47 to rotate. The two meshing gears 47 cause the two clamping arms 42 to rotate in opposite directions at the same speed, so that the left and right clamping arms 42 open at the same angle and speed, ensuring that the tool 3 smoothly disengages from the clamping arm 42. When the new tool 3 is squeezed into the opening of the two clamping arms 42, the rotation of the roller 43 guides the new tool 3 to move into the two clamping arms 42. During the pushing process of the tool 3, the two clamping arms 42 rotate outward due to the pushing force, and the return spring 46 and the spring piece 44 are compressed. As the tool 3 is loaded into the clamping area of ​​the clamping arms 42, the elastic return force of the return spring 46 and the U-shaped spring piece 44 pushes the clamping arms 42 together, causing the clamping arms 42 and the gear 47 to rotate in the opposite direction with the clamping arm rotating shaft 41, so that the clamping arms 42 gradually close. The left and right gears 47 re-engage synchronously in the opposite direction with the clamping arm rotating shaft 41. Through the rigid meshing relationship, the closing angle of the two clamping arms 42 is forced to be consistent, ensuring that the axis of the tool 3 in the tool clamping device 4 coincides with the design reference axis of the tool clamping device 4. With the precise indexing and positioning of the tool disk 5, when changing tools, after the target tool rotates to the preset position with the tool disk, its axis is precisely aligned with the axis of the fixed spindle of the machine tool. Moreover, after changing multiple tools, this coaxiality requirement can be repeatedly maintained. Finally, the clamping arm 42 returns to the closed clamping state, completing the tool change. The tool number sticker 2 on the outer wall of the tool head cover 1 helps the operator quickly identify the tool type and improves tool change efficiency.

[0032] It should be noted that the machine tool spindle axis is a fixed reference. The tool turret achieves precise rotation and positioning through a servo motor drive and an indexing and positioning mechanism (such as a photoelectric encoder and indexing plate). During tool changing, the tool turret precisely delivers the tool holder containing the target tool to the corresponding position on the spindle, ensuring that the design reference axis of the tool holder coincides with the spindle axis. The synchronous meshing structure of the two sector-shaped gears 47 ensures that the axis of the tool 3 within the clamping arm 42 does not deviate and remains consistent with the reference axis of the tool holder, allowing for precise alignment with the spindle axis after any tool change, meeting the accuracy requirements of multi-tool alternating machining.

[0033] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An automatic tool changer for a metalworking machine tool, comprising a tool disc, wherein a plurality of tool clamping devices are arranged along the circumference of the tool disc, and a tool disc cover is provided on the front side of the tool disc, characterized in that, The tool clamping device includes an L-shaped mounting base. Clamping arm mounting slots are respectively provided on both sides of the bottom of the mounting base. A clamping arm rotating shaft is rotatably connected to the top and bottom of the clamping arm mounting slots. A clamping arm is fixed to the clamping arm rotating shaft and is located within the clamping arm mounting slot. A U-shaped spring is provided between the rear ends of the two clamping arms. A return spring is provided between the two ends of the spring. A sector-shaped gear is fixedly connected to the clamping arm rotating shaft at the bottom of the mounting base, and the two gears mesh with each other.

2. The automatic tool changer for a metalworking machine tool according to claim 1, characterized in that, The spring includes a U-shaped spring body, with a fixing hole on the horizontal arm and a locking hole on the vertical arm; a sleeve is provided at the end of the vertical arm, and the two ends of the return spring are located inside the sleeve.

3. The automatic tool changer for a metalworking machine tool according to claim 2, characterized in that, The connection between the vertical and horizontal arms of the spring is designed as an arc-shaped structure.

4. An automatic tool changer for a metalworking machine tool according to claim 2 or 3, characterized in that, The surfaces of the vertical and / or horizontal arms of the spring are provided with interlaced reinforcing ribs.

5. An automatic tool changer for a metalworking machine tool according to claim 4, characterized in that, The intersecting reinforcing ribs have rounded angles at their joints.

6. An automatic tool changer for a metalworking machine tool according to claim 1, characterized in that, The upper back of the mounting base is provided with a reinforcing arm, and the reinforcing arm is provided with a through hole for the spring clip to pass through.

7. An automatic tool changer for a metalworking machine tool according to claim 1, characterized in that, The end of the clamping arm is provided with a roller mounting groove. A roller shaft is fixed at the top and bottom of the roller mounting groove. A roller is rotatably connected to the roller shaft. The roller is located in the roller mounting groove and is coaxial with the roller shaft.

8. An automatic tool changer for a metalworking machine tool according to claim 1, characterized in that, The outer wall of the cutter head cover is affixed with a tool number sticker corresponding to the tool clamping device.

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