An external cooler to internal cooler tool holder with automatic tool change function

Abstract

An externally cooled to internally cooled tool holder supporting automatic tool changing includes a bearing section, a sealing section, and an automatic tool changing function section. The bearing section provides stable support to the tool holder through a pair of bearings, improving the overall structural rigidity of the product. The sealing section seals the cutting fluid within a pair of sealing rings and guides it to a central through-hole in the tool holder. A specially designed cutting fluid flow channel reduces pressure and flow loss, improving cooling efficiency. The bearing section and the sealing section are connected by a snap-fit ​​mechanism, resulting in a higher degree of integration and greater overall structural stability for the externally cooled to internally cooled tool holder. The automatic tool changing function section uses a push rod to move a stop pin. The stop structure is designed on the upper part of the tool holder to prevent chips from entering the stop structure during use, which could cause stop structure failure and affect the automatic tool changing function. This invention solves the problem of achieving internal tool cooling on machine tools without a central cooling outlet, effectively improving machining quality and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of machine tool holders and relates to an external cooling to internal cooling tool holder that supports automatic tool changing. Background Technology

[0002] Cooling of cutting tools on CNC machine tools is mostly achieved through external cooling, which involves spraying coolant onto the tool via a cooling mechanism mounted on the machine spindle. However, when drilling deep holes or machining flat surfaces, the coolant cannot be fully sprayed onto the contact surface between the tool and the workpiece, resulting in poor cooling performance. To improve cooling efficiency and increase production quality, the machining industry has begun using internally cooled cutting tools with internal cooling water outlets, but this generally requires the machine tool to have a center water outlet. On machine tools without a center water outlet, the use of internally cooled cutting tools is severely limited.

[0003] For machine tools without a central cooling outlet, some external-to-internal-cooling tool holders have emerged on the market that can convert external cooling to central cooling. For example, Chinese patent CN 202668249 U discloses an internal-cooling conversion tool holder device. This patent solves the problem of using internally cooled tools in machine tools without a central cooling outlet by setting an opening on the tool holder and introducing cutting fluid from the outside. However, in this patent, the cutting fluid sealing part is not separated from the bearing, making the bearing susceptible to damage from the cutting fluid. Furthermore, this patent does not support automatic tool changing.

[0004] Chinese patent CN 205166543 U discloses an external cooling to internal cooling tool holder structure. In this patent, the rotating part and the fixed part are only sealed with a sealing ring, and no bearing support structure is designed. Although the structure is simple, it also does not support automatic tool changing function.

[0005] Therefore, it is of great significance to design a tool holder that can effectively reduce tool temperature, extend tool life, help remove chips, improve machining results, and support automatic tool changing to adapt to the conversion of external cooling to internal cooling in automated machining. Summary of the Invention

[0006] The purpose of this invention is to provide an external cooling to internal cooling tool holder that supports automatic tool changing, in order to solve the problem of using internal cooling tools to improve machining quality and efficiency on machine tools without center cooling function and in automated production processes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An externally cooled to internally cooled tool holder supporting automatic tool change includes a tool holder, a bearing portion, a sealing portion, and an ATC tool changer. The tool holder axially passes through the bearing portion and the sealing portion in sequence, and the bearing portion and the sealing portion are connected together by a snap-fit. The tool holder and the bearing portion are connected together by a lock nut. When the tool holder is mounted on the spindle and rotates at high speed, the bearing portion provides support. The ATC tool changer is laterally fixed to the bearing portion. One end of the tool holder is connected to the machine tool, and the other end can be used to clamp the tool. The bearing assembly includes a bearing housing, a first bearing, a second bearing, and a locking nut. The first bearing and the second bearing are installed in the bearing housing and separated by a spacer, and are fixed by the locking nut. The sealing part includes a sealing middle shell, an upper cover, and a lower cover, which are connected by screws to form the main body of the sealing part. The first sealing ring and the second sealing ring are installed in the main body. The ATC tool changer includes an ATC base, a height adjustment pad, and an internal water inlet stud. The height adjustment pad is placed in a through hole on the ATC base, and the upper part of the through hole is threaded, allowing the internal water inlet stud to be connected. The ATC tool changer also includes a spindle positioning plate and a water inlet fixing seat. The spindle positioning plate is installed below the spindle, and the water inlet fixing seat is installed on the spindle positioning plate. The ATC tool changer also includes a stop mechanism, including a spring, a stop pin, a positioning screw, and a push rod. The stop pin and the push rod are flexibly connected together, positioned by the positioning screw, and reset under the action of the spring.

[0008] Furthermore, the first and second bearings are a pair of angular contact ball bearings configured back-to-back, and the bearing clearance and preload are adjusted by spacers and lock nuts; the tool holder uses standard ER specification water-stop spring collets and nuts to install internally cooled tools.

[0009] Furthermore, the lower part of the tool holder flange structure is designed with 4 threaded holes. The oil baffle is connected to the tool holder by screws. The lower part of the oil baffle is designed with 4 grooves evenly arranged in a ring. The stop pin can be inserted into or removed from the groove under the action of the push rod, thereby realizing the locking and releasing of the tool holder. The positioning screw is used to guide and position the stop pin during movement. The reset movement of the push rod is realized by a spring.

[0010] Furthermore, the shaft-shaped structure below the tool holder flange structure is also designed with guide holes on the tool holder. The guide holes on the tool holder are elongated, there are 5 of them, and they are connected to the central through hole of the tool holder. The center line of the guide holes has a certain eccentricity e with the rotation center line of the tool holder. The value of the eccentricity e is in the range of 1-5mm. The function of the eccentricity e is to reduce the pressure loss of the cutting fluid inside the tool holder.

[0011] Furthermore, a guide hole is designed on the corresponding position of the locking nut. It is also elongated and larger than the guide hole on the tool holder. When the locking nut is installed in place, it is aligned with the center of the guide hole on the tool holder.

[0012] Furthermore, the bearing housing has three stepped grooves on its bottom ring. The card is fixed to the first groove with screws. The top cover has a cover buckle structure that cooperates with the card. The cover is buckled into the second groove, and then rotated clockwise to connect the sealing part and the bearing part together. The bearing housing has three stepped grooves on its bottom, three matching cards, and three corresponding cover buckle structures.

[0013] Furthermore, the height of the top surface of the internal water inlet stud after installation is adjusted by a height adjustment pad; the water inlet fixing seat and the spindle positioning plate are connected and installed below the spindle. When the tool holder is installed into the spindle, the internal water inlet stud is inserted into the hole on the water inlet fixing seat, and the cutting fluid can flow into the tool holder.

[0014] Furthermore, the ATC housing is laterally fixed to the bearing housing by screws. Between the sealed inner shell and the ATC housing, there is a connecting pipe, a first sealing gasket, and a second sealing gasket. The connecting pipe connects the sealed inner shell to the ATC housing, and the first and second sealing gaskets are respectively installed on both sides of the connecting pipe to prevent cutting fluid leakage.

[0015] An externally cooled to internally cooled tool holder that supports automatic tool changing has the following internal cutting fluid flow sequence: inlet fixing seat → internal inlet stud → ATC seat → connecting pipe → sealing middle shell → lock nut → tool holder.

[0016] An externally cooled to internally cooled tool holder that supports automatic tool changing has interface types including BT30, BT40, BT50, HSK A50, and HSK A63 with machine tools, and can be used on machine tools configured with these interface types.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention significantly improves the structural rigidity of the external cooling to internal cooling tool holder through the support structure of the double bearing, enabling it to bear greater loads and maintain better stability during use, thus effectively improving the machining effect; 2) By designing the bearing support structure and the cutting fluid sealing structure independently, this invention effectively avoids the problem of cutting fluid leakage during the use of externally cooled to internally cooled tool holders, which may damage the bearing function and life, and greatly improves the reliability of externally cooled to internally cooled tool holders and increases the service life of the tool holders. 3) The snap-fit ​​design between the bearing support structure and the cutting fluid sealing structure of the present invention not only cleverly hides the connection structure between the two parts, making the product appearance more complete and unified, but also makes the overall structure of the external cooling to internal cooling tool holder more integrated, the overall size of the product is smaller, occupies less space, effectively reduces the risk of interference during production, and also makes the structural connection more stable and reliable. 4) The stop structure designed in this invention enables the external cooling to internal cooling tool holder to achieve automatic tool changing function inside the machine tool, which not only makes it more convenient to use, but also supports the automation of the production process and improves the production efficiency of the entire production process. 5) The stop structure designed in this invention is small in size and compact in structure, and the core functional structure is hidden inside the shell, which can avoid the influence of chips and cutting fluid, and the working performance is stable and reliable. 6) The special flow channel design included in this invention, with its strip-shaped and staggered guide hole design, effectively reduces the flow rate and pressure loss of the cutting fluid output during the process of external cooling to internal cooling, thereby improving the output efficiency of the cutting fluid. 7) The special flow channel design included in this invention forms an obtuse angle between the axis of the guide hole and the linear velocity of the tool holder surface during the operation of the externally cooled to internally cooled tool holder. This creates a "scooping" effect during movement, further reducing the flow rate and pressure loss of the cutting fluid, making it more energy-efficient and effective. 8) Through product structure and special flow channel design, this invention improves the output efficiency of cutting fluid, thereby increasing the flow rate and speed of cutting fluid reaching the contact surface between the tool and the workpiece. This not only effectively ensures the cooling requirements during machining, but also makes chip removal smoother due to the sufficient flow rate. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a front structural cross-sectional view of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the bearing housing of the present invention; Figure 3 This is a schematic diagram of the upper cover structure of the present invention; Figure 4 yes Figure 1 Schematic diagram of section AA; Figure 5 This is a front view schematic diagram of the locking nut structure in this invention; Figure 6 This is a schematic diagram of the flow guide hole at the lower part of the tool holder in this invention; Wherein: 1-tool holder, 2-oil baffle, 3-first bearing, 4-second bearing, 5-bearing seat, 6-spacer, 7-upper cover, 8-first sealing ring, 9-sealing middle shell, 10-lower cover, 11-locking nut, 12-second sealing ring, 13-first sealing gasket, 14-connecting pipe, 15-second sealing gasket, 16-ATC seat, 17-spring, 18-stop pin, 19-height adjustment pad, 20-positioning screw, 21-inner water inlet stud, 22-push rod, 23-water inlet fixing seat, 24-spindle positioning plate, 25-card, 26-first-stage groove, 27-second-stage groove, 28-upper cover snap-fit ​​structure, 29-guide hole on the locking nut, 30-guide hole on the tool holder. Detailed Implementation

[0019] The invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0020] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0021] Following the above technical solutions, such as Figures 1 to 6 As shown in the figure, this embodiment provides an external cooling to internal cooling tool holder that supports automatic tool changing, which solves the problem of using internal cooling tools to improve machining quality and supporting automatic tool changing to improve machining efficiency on machine tools without center cooling function.

[0022] This invention provides an external cooler to internal cooler tool holder that supports automatic tool changing, such as... Figure 1 As shown, an oil baffle 2 is installed on the handle 1, and four grooves are evenly distributed below the oil baffle 2; the push rod 22 is installed on the ATC seat 16, and there is a spring 17 at its lower part. The stop pin 18 has a through hole in the middle, through which the positioning screw 20 can pass and support the stop pin 18 to move up and down together with the push rod. The pin part of the stop pin 18 can extend into the groove below the oil baffle 2.

[0023] Furthermore, when the externally cooled to internally cooled tool holder is correctly installed on a machine tool with a spindle orientation function, the push rod 22 is pressed down by the inlet fixing seat 23, and the push rod 22 drives the stop pin to move downward, releasing the tool holder so that it can rotate. When machining stops, due to the spindle orientation function, the tool holder stops at the initial angle, and the stop pin 18 is aligned with the groove below the oil baffle 2. When the externally cooled to internally cooled tool holder is removed from the spindle, the push rod 22 drives the stop pin 18 upward to insert into the groove, thereby preventing the tool holder 1 from rotating.

[0024] Furthermore, the internal water inlet stud 21 and ATC seat 16 are connected by threads and the distance between them and the water inlet fixing seat 23 after installation is adjusted by the height adjustment pad 19. The spindle positioning plate 24 is installed below the spindle and connected to the water inlet fixing seat 23 by bolts. The ATC seat 16 and the sealing middle shell 9 are connected by a connecting pipe 14 to make the internal cutting fluid channels of the two connected by a first sealing gasket 13 and a second sealing gasket 15 on both sides of the connecting pipe 14 to seal the cutting fluid and prevent leakage.

[0025] Furthermore, such as Figure 2 The diagram shows the bottom structure of the bearing housing. Three stepped grooves are machined in an annular pattern on the bearing housing 5. Threaded holes are drilled in the first groove 26, and the clip 25 is fixed to the bearing housing 5 by screws.

[0026] Furthermore, such as Figure 3 The diagram shows the upper cover snap-fit ​​structure 28 and its interaction with the card 25. During installation, the upper cover snap-fit ​​structure 28 is first placed into the second groove 27 of the stepped groove at the bottom of the bearing seat 5, and then the bearing seat 5 is rotated to achieve a stable connection with the upper cover 7.

[0027] Furthermore, such as Figure 4 , Figure 5 , Figure 6 As shown, a guide hole 30 is designed on the tool holder 1, and a guide hole 29 is designed on the locking nut 11. The two can be aligned when the locking nut is tightened, and the cutting fluid can pass through. A radial through hole is opened on the sealing shell 9, which connects the space between the locking nut 11 and the ATC seat 16. In actual use, the cutting fluid enters from the inlet fixing seat 23, passes through the ATC seat 16, the inner water inlet stud 21, the height adjustment pad 19, the connecting pipe 14, the sealing shell 9, and finally enters the through hole in the center of the tool holder 1 and finally flows out from the outlet of the internal cooling tool.

[0028] Furthermore, after the locking nut 11 is tightened, the center line of the guide hole 29 on the locking nut is aligned with the center line of the guide hole 30 on the tool holder. However, since the width of the guide hole 29 on the locking nut is longer than that of the guide hole 30 on the tool holder, a certain deviation in their positions is allowed. The arrow in the figure indicates the rotation direction of the tool holder. The axis of the guide hole 29 on the locking nut and the guide hole 30 on the tool holder has an eccentricity e with the rotation center of the tool holder. The value of this eccentricity ranges from 1 to 5 mm, thus forming a "scooping" effect when the tool holder 1 rotates with the locking nut 11, which reduces the pressure loss of the cutting fluid.

[0029] Furthermore, in the entire cutting fluid flow path, when the cutting fluid passes through the connecting pipe 14, the first sealing gasket 13 and the second sealing gasket 15 on its left and right sides can prevent the cutting fluid from flowing out from the gap between the ATC seat 16, the connecting pipe 14 and the sealing shell 9; when the cutting fluid enters the sealing shell 9, the first sealing ring 8 and the second sealing ring 12 can seal it in the annular groove in the middle of the sealing shell to prevent cutting fluid leakage.

[0030] The working process of this invention is as follows: In use, first connect the inlet fixing seat 23 to the spindle positioning plate 24 and install it in a suitable position below the machine tool spindle. First, manually install the tool holder on the machine tool spindle, ensuring that the inner inlet stud 21 can extend into the hole of the inlet fixing seat 23 and the push rod 22 is pressed down, allowing the tool holder 1 to rotate. If the tool holder 1 cannot rotate, the height of the height adjustment pad 19 needs to be adjusted. After debugging, the automatic tool change function can be used. Then, the cutting fluid channel of the inlet fixing seat 23 is connected. At this time, the cutting fluid enters the sealing shell 9 from the ATC seat 16 through the connecting pipe 14 and flows in from the locking nut 11 and the through hole on the tool holder 1 under the sealing action of the first sealing ring 8 and the second sealing ring 12. Finally, it flows out from the outlet of the internal cooling tool. At this time, the spindle can be rotated for machining. After machining is completed, the automatic tool changer removes the tool holder from the spindle. At this time, the push rod 22 extends so that the stop pin 18 extends into the pin hole in the oil baffle 2 to lock the tool holder with the external structure, ensuring that when the automatic tool changer reinstalls it on the spindle, the internal water inlet stud 21 can be inserted into the inlet fixing seat 23.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements will all fall within the protection scope defined by the submitted claims.

Claims

1. An external-cooled internal-cooled shank supporting an automatic tool changing function, characterized by: The machine tool includes a tool holder (1), a bearing section, a sealing section, and an ATC tool changer. The tool holder (1) passes through the bearing section and the sealing section axially in sequence, and the bearing section and the sealing section are connected together by a snap fastener. The tool holder (1) is connected to the bearing section by a locking nut (11). The ATC tool changer is laterally fixed on the bearing section. One end of the tool holder (1) is connected to the machine tool, and the other end can be used to clamp the tool. The bearing section includes a bearing seat (5), a first bearing (3), a second bearing (4), and a locking nut (11). The first bearing (3) and the second bearing (4) are installed in the bearing seat (5) and separated by a spacer (6), and fixed by the locking nut (11). The sealing section includes a sealing middle shell (9), an upper cover (7), and a lower cover (10). The three are connected by screws to form the main body of the sealing section. The first sealing ring (8) and the second sealing ring (9) are connected by screws. The ring (12) is installed in the main body; the ATC tool changer includes an ATC seat (16), a height adjustment pad (19), and an inner water inlet stud (21). The height adjustment pad (19) is placed in a through hole on the ATC seat (16). The upper part of the through hole is threaded, and the inner water inlet stud (21) can be connected to it; the ATC tool changer also includes a spindle positioning plate (24) and a water inlet fixing seat (23). The spindle positioning plate (24) is installed below the spindle, and the water inlet fixing seat (23) is installed on the spindle positioning plate (24); the ATC tool changer also includes a stop mechanism, including a spring (17), a stop pin (18), a positioning screw (20), and a push rod (22). The stop pin (18) and the push rod (22) are flexibly connected together, positioned by the positioning screw (20), and reset under the action of the spring (17); The shaft structure below the flange structure of the tool holder (1) is also designed with guide holes (30) on the tool holder. The guide holes (30) on the tool holder are long strips in shape and there are 5 of them. The guide holes (30) on the tool holder are connected to the central through hole of the tool holder, and their center line is eccentric to the rotation center line of the tool holder by a certain amount e. The value range of the eccentricity e is 1-5mm. The function of the eccentricity e is to reduce the pressure loss of the cutting fluid inside the tool holder. A guide hole (29) is also designed on the corresponding position of the locking nut (11). It is also long and narrow and larger than the guide hole (30) on the tool holder. When the locking nut (11) is installed in place, the guide hole (29) on the locking nut is aligned with the center of the guide hole (30) on the tool holder.

2. The external-cooled internal-cooled shank supporting automatic tool changing according to claim 1, wherein: The first bearing (3) and the second bearing (4) are a pair of angular contact ball bearings configured back to back. The bearing clearance and preload are adjusted by spacer (6) and lock nut (11). The tool holder (1) uses a standard ER specification water-stop spring collet and nut to install the internal cooling tool.

3. The external-cooled internal-cooled shank supporting automatic tool changing according to claim 1, wherein: The bearing seat (5) has three stepped grooves on its bottom ring. The card (25) is fixed to the first groove (26) with screws. The top cover (7) has a top cover buckle structure (28) that matches the card (25). The top cover buckle structure (28) is inserted into the second groove (27) and then rotated clockwise to connect the sealing part and the bearing part together. The bearing seat (5) has three stepped grooves at the bottom, and there are three matching cards (25) and three corresponding top cover buckle structures (28).

4. The external cooling to internal cooling tool holder supporting automatic tool changing function according to claim 1, characterized in that: The tool holder (1) has four threaded holes at the bottom of the flange structure. The oil baffle (2) is connected to the tool holder by screws. The oil baffle (2) has four grooves evenly arranged in a ring at the bottom. The stop pin (18) can be inserted into or removed from the groove under the action of the push rod (22), thereby realizing the locking and releasing of the tool holder. The positioning screw (20) is used to guide and position the stop pin (18) when it moves. The reset movement of the push rod (22) is realized by the spring (17).

5. A tool holder for switching from external cooling to internal cooling with automatic tool changing function as described in claim 1, characterized in that: The height of the inner water inlet stud (21) after installation is adjusted by the height adjustment pad (19); the water inlet fixing seat (23) and the spindle positioning plate (24) are connected and installed below the spindle. When the tool holder is installed into the spindle, the inner water inlet stud (21) is inserted into the hole on the water inlet fixing seat (23) and the cutting fluid can flow into the tool holder.

6. A tool holder for switching from external cooling to internal cooling with automatic tool changing function as described in claim 1, characterized in that: The interface between the tool holder (1) and the machine tool is compatible with specifications BT30, BT40, BT50, HSK A50, and HSK A63.

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