Double-tool-magazine vertical machine tool tool changing mechanism and method

Abstract

The invention belongs to the technical field of machine tool machining equipment, particularly relates to a double-tool-magazine vertical machine tool tool changing mechanism and method, and solves the problems that an existing tool changing mechanism is complex in structure and is easily eroded by cuttings. The mechanism is assembled at the lower end of the vertical annular tool magazine and used for exchanging positions of a tool bit at the tool magazine output end and a tool bit main shaft. The clamping mechanism comprises a cross arm which is horizontally and rotatably arranged below the tool magazine, and clamping positions for clamping the tool bits are arranged at the two ends of the cross arm and used for mutually exchanging the positions of the two tool bits; two tool bit locking modules are arranged corresponding to the two clamping positions and used for locking or unlocking tool bits on the clamping positions. The movable end of the tool bit locking module is arranged in the cross arm, penetrates out of the clamping position and is matched with the clamping position to lock or unlock the handle part of the tool bit; according to the scheme, the movable end of the locking module is arranged in the cross arm, the structure is compact, precise parts are effectively protected, and the reliability and durability of the tool changing mechanism are improved.

Description

Technical Field

[0001] This invention relates to the field of machine tool processing equipment technology, and in particular to a tool changing mechanism and method for a vertical machine tool with a double tool magazine. Background Technology

[0002] In modern manufacturing, CNC machine tools, especially machining centers, are widely used due to their high precision and efficiency. To reduce non-machining time and improve equipment utilization, tool magazines and automatic tool changers have become standard configurations. For vertical machining centers, the spindle is usually perpendicular to the worktable, while tool magazines come in various forms, such as disc type, bucket type, and chain type, depending on their layout. Among them, the vertical ring tool magazine is often used in situations where space is limited or a large number of tools are required due to its compact structure and large tool storage capacity. When a machine tool is equipped with two vertical ring tool magazines (i.e., a double tool magazine), the tool capacity can be further expanded to meet the needs of one-time clamping and machining of complex parts.

[0003] In existing vertical circular tool magazine automated tool changer (AGC) technologies, the core task of the tool changing mechanism is to quickly and accurately exchange the tool to be changed on the spindle with the tool to be selected in the tool magazine. Common tool changing methods include tool changing without a robotic arm (such as directly retrieving the tool by moving the tool magazine) and tool changing with a robotic arm. In tool changing with a robotic arm, the robotic arm typically adopts a dual-arm rotary structure, such as the common 180° rotating dual-jaw robotic arm. This type of robotic arm uses two symmetrical jaws to grasp the tool from the spindle and the tool magazine's output end respectively, and then rotates 180° to achieve the exchange of tool positions.

[0004] However, existing tool changing mechanisms still have some limitations in practical applications for dual tool magazines, especially dual vertical ring tool magazines. First, traditional dual-arm robotic arms are usually set up independently of the tool magazine, requiring additional space on one side of the machine tool's working area. This may interfere with the compact layout of a dual tool magazine or increase the overall size of the machine tool. Second, the drive and control components of the tool changing mechanism are usually exposed or integrated into a complex gearbox. This not only results in a complex structure, but also makes moving parts such as grippers and connecting rods susceptible to corrosion from chips and coolant generated during machining, affecting their long-term reliability and accuracy. Furthermore, the gripping mechanism of traditional robotic arms often uses complex linkage mechanisms to open and close the grippers. During high-speed tool changes, the stability of the gripping force and the accuracy of the tool holder positioning are crucial to ensuring successful tool changes. Improper design can easily lead to tool drops or deviations in the tool changing position, thereby causing machine tool failures or machining accidents.

[0005] Furthermore, the tool changing mechanism installed below the tool magazine requires extremely high precision in its alignment with the tool magazine's output end and the spindle. After prolonged operation or high-speed rotational positioning, the accumulated rotational error of the tool changing crossarm may affect the precise alignment of the tool holder and clamping position, leading to the tool head locking module failing to accurately lock the tool head, or the tool heads colliding during the exchange process. Traditional solutions typically rely on high-precision rotary indexing mechanisms and rigorous periodic calibration, which increases manufacturing costs and maintenance complexity.

[0006] Therefore, developing a compact tool changing mechanism specifically designed for under-mounted configurations in dual-tool magazine vertical machine tools, capable of effectively protecting internal precision components and maintaining high tool changing accuracy and reliability over extended periods, has become a pressing technical problem for those skilled in the art. This invention addresses the shortcomings of the existing technology by proposing an improvement. Summary of the Invention

[0007] The purpose of this invention is to provide a tool changing mechanism and method for a vertical machine tool with a dual-tool magazine, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a tool changing mechanism for a dual-tool magazine vertical machine tool, assembled at the lower end of the vertical annular tool magazine of the dual-tool magazine vertical machine tool, used to interchange the positions of the tool heads on the tool head spindle and the tool head exit end of the vertical annular tool magazine, characterized in that it includes: A horizontal arm is rotatably mounted below the vertical annular tool magazine and has clamping positions for holding tool heads at both ends. It is configured to interchange the positions of the tool heads at the magazine exit end and the tool head spindle. The cutter head locking module has two corresponding clamps and is configured to lock or unlock the cutter head at the clamping position; The movable end of the blade locking assembly is located inside the cross arm and extends through the clamping position, and cooperates with it to lock or unlock the handle of the blade.

[0009] The tool changing mechanism for a vertical machine tool with a double tool magazine according to the present invention includes a notch groove on the end side wall of the horizontal arm, and a semi-circular positioning groove for positioning the tool shank of the tool head on the side wall along the width direction of the horizontal arm, the positioning groove being the clamping position; the movable end of the tool head locking module extends out of the notch groove along the length direction of the horizontal arm.

[0010] The tool changing mechanism for a vertical machine tool with a dual tool magazine according to the present invention includes a tool head locking module comprising a movable shaft movably arranged along the length direction of the horizontal arm, and a drive assembly for driving the movable shaft to reciprocate along a fixed axis; one end of the movable shaft extending into the notch is fixed with a clamping block for pressing the shank against the side wall of the positioning groove; in the locked state, the clamping block is located on the front side of the positioning groove and surrounds it to form a C-shaped positioning cavity with an opening diameter smaller than the diameter of the positioning groove.

[0011] The tool changing mechanism for a vertical machine tool with a dual tool magazine according to the present invention includes a positioning plane on the positioning block facing the shank. The positioning plane is eccentrically positioned with respect to the axis of the movable shaft. In the locked state, the positioning plane is tangent to the peripheral sidewall of the shank.

[0012] The tool changing mechanism for a vertical machine tool with a dual tool magazine according to the present invention includes a drive assembly comprising a drive shaft coaxial with the movable shaft and axially movable within the cross arm, a drive motor for driving the drive shaft to rotate on its fixed axis, and a transmission unit for transmittingly connecting the drive motor and the drive shaft; the end of the movable shaft opposite to the positioning groove is provided with a slot adapted to the drive shaft, the inner wall of the slot is provided with an internal thread, and the drive shaft is provided with an external thread adapted to the internal thread.

[0013] The tool changing mechanism for a vertical machine tool with a dual tool magazine according to the present invention includes a drive motor shaft that is vertically upward and a drive motor that is fixed to the lower surface of the cross arm by a protective cover. The lower surface of the cross arm is provided with a mounting groove for mounting the transmission unit above the protective cover. The drive shaft extends into the mounting groove and is connected to the drive motor shaft through the transmission unit.

[0014] The tool changing mechanism for a vertical machine tool with a dual-tool magazine according to the present invention includes a transmission unit comprising a first bevel gear coaxially fixed on the rotating shaft with its meshing surface facing upward, a second bevel gear meshing perpendicularly with the first bevel gear, and a connecting shaft rotatably connected coaxially with the second bevel gear; one end of the connecting shaft facing the rotating shaft is horizontally rotatably connected to the rotating shaft via a bearing; the drive shaft is axially separable from the second bevel gear via a spline groove provided on the end face of the second bevel gear.

[0015] The tool changing mechanism for a vertical machine tool with a dual-tool magazine according to the present invention includes a first end face cam coaxially fixed on the rotating shaft above the connecting shaft, a second end face cam coaxially engaged with the first end face cam above it, and a position positioning shaft coaxially provided at the upper end of the second end face cam. The upper end of the position positioning shaft extends out of the mounting groove. When the position positioning shaft rises to its position, it is inserted into the position calibration groove at the lower end of the vertical annular tool magazine, thereby eliminating the accumulated rotational error of the cross arm.

[0016] The tool changing mechanism for a vertical machine tool with a dual tool magazine according to the present invention includes a guide groove on the inner wall of the mounting groove for guiding the up-and-down movement of the second end face cam. An elastic reset member is provided in the guide groove to provide a downward elastic reset force to the second end face cam. A cover is provided on the upper surface of the cross arm to seal the elastic reset member in the guide groove. The cover is provided with a through hole for the position positioning shaft to pass through.

[0017] Furthermore, the present invention also provides a tool changing method for a tool changing mechanism of a dual-tool magazine vertical machine tool, the method comprising the following steps: Step 1: Rotate the tool head to be replaced in the vertical ring tool magazine to the exit end, and move the tool head spindle to the preset tool changing position so that the current tool head on the spindle and the tool head to be replaced at the exit end of the tool magazine are at the same horizontal height and their axes are parallel to each other. Step 2: Drive the horizontal arm to rotate horizontally to the initial tool change position, so that the clamping positions at both ends of the horizontal arm are directly opposite the tool head shank on the spindle and the tool head shank at the tool magazine exit end, respectively. Step 3: Activate the position calibration mechanism to drive the position positioning shaft to rise and insert it into the corresponding position calibration slot at the lower end of the vertical ring tool magazine, so as to eliminate the positioning error accumulated by the long-term rotation of the cross arm and ensure the precise alignment of the clamping position with the tool head shank. Step 4: Drive the two cutter head locking modules to move simultaneously, so that their movable ends extend along the length of the horizontal arm, locking the shanks of the two cutter heads in their corresponding clamping positions. Step 5: Control the spindle to release the clamp on the current tool head, and at the same time control the tool magazine to release the clamp on the tool head to be replaced. Control the spindle and tool magazine to move backward a preset distance along the axis respectively, so that the two tool heads are completely disengaged and only held by the cross arm. Step 6: Drive the cross arm to rotate 180 degrees around its center of rotation, and interchange the positions of the two cutter heads; Step 7: Control the spindle and tool magazine to move axially to reset, so that the exchanged tool head shanks are accurately inserted into the spindle taper hole and the tool magazine exit end clamping hole respectively, and then re-clamp them; Step 8: Drive the cutter head locking module to reverse its movement, causing its movable end to retract and release the lock on the two cutter head shanks; Step 9: Drive the position positioning axis to descend and disengage from the calibration slot, and drive the cross arm to rotate in the opposite direction to return to the initial waiting position, completing one tool change cycle.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a tool changing mechanism for a vertical machine tool with a dual-tool magazine. By horizontally rotating a horizontal arm positioned below a vertical annular tool magazine and providing clamping positions at both ends of the arm, it achieves simultaneous gripping and exchange of tool heads from the tool magazine's output end and the spindle. The compact structure effectively utilizes the unused space below the tool magazine and avoids interference with other machine tool components. Crucially, this invention integrates the movable end of the tool head locking module within the horizontal arm, extending only from the clamping position at its end to perform locking or unlocking actions. This design, which encloses the core drive components within the horizontal arm cavity, not only significantly improves the structural compactness but, more importantly, effectively isolates contaminants such as chips and cutting fluid generated during machining. This significantly improves the protective performance, operational reliability, and long-term service life of the tool changing mechanism, solving the technical problem of traditional exposed robotic arms being easily contaminated and jammed. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is an overall structural diagram of the present invention.

[0021] Figure 2 for Figure 1 A magnified view of the local structure.

[0022] Figure 3 This is a structural diagram of the cross arm and cutter head locking module assembly of the present invention.

[0023] Figure 4 for Figure 3 A bottom view.

[0024] Figure 5 for Figure 4 AA sectional view.

[0025] Figure 6 for Figure 5 A magnified view of the local structure.

[0026] Figure 7 for Figure 5 A magnified view of the local structure.

[0027] Figure 8 This is an exploded view of the transmission unit of the present invention. Detailed Implementation

[0028] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0031] Furthermore, the terms indicating orientation, such as "up," "down," "left," "right," "upper end," "lower end," and "longitudinal," are all based on the posture and position of the device or equipment described in this solution during normal use.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0033] Example 1 This embodiment discloses, as follows: Figures 1 to 8 The tool changing mechanism shown is mounted on the lower end of the vertical annular tool magazine A1 of the dual-tool magazine vertical machine tool, and is used to exchange the positions of the tool heads on the tool head spindle and the tool magazine outlet end.

[0034] The tool changing mechanism mainly includes a cross arm 100 and a tool head locking module 200.

[0035] The horizontal arm 100 is horizontally mounted below the vertical ring-shaped tool magazine via a rotary drive device A2 (rotary lifting servo motor, a common module in historical machine tool tool magazines) integrated with the tool magazine. The horizontal arm 100 is elongated (machined from a rectangular sheet metal part, with its width horizontal), and has a clamping position 110 at each end for holding the tool head 300. The horizontal arm 100 is configured to rotate 180 degrees horizontally between an initial position and a tool change position, thereby exchanging the positions of the two tool heads 300 facing the tool magazine exit end 310 and the tool head spindle 320.

[0036] The cutter head locking module 200 has two corresponding clamping positions 110. The core function of each cutter head locking module 200 is to lock or unlock the cutter head 300 at its corresponding clamping position 110. To achieve this function, each cutter head locking module 200 has a movable end. The main body of the movable end is located in the internal cavity of the cross arm 100, and only the part that performs the locking extends out from the clamping position 110 and cooperates with the clamping position 110 to lock or unlock the shank 330 of the cutter head 300. This design, in which the main body of the movable end is built into the cross arm 100, effectively protects the precision components from external chips and coolant corrosion.

[0037] Specifically, a notch 120 is formed on the end sidewall of the horizontal arm 100. The opening of the notch 120 faces the rotation direction, and the end of the notch 120 away from the rotation axis of the horizontal arm 100 directly penetrates the end face of the end of the horizontal arm. On the sidewall of the notch 120 along the length direction of the horizontal arm 100, a semi-circular positioning groove 121 for positioning the shank 330 of the cutter head 300 is machined. This semi-circular positioning groove 121 constitutes the aforementioned clamping position 110. Correspondingly, the movable end of the cutter head locking module 200 extends out from the inside of the horizontal arm 100 along the length direction of the horizontal arm 100 and extends into the notch 120.

[0038] In this embodiment, the cutter head locking module 200 includes a movable shaft 210 and a drive assembly 220. The movable shaft 210 is slidably disposed inside the cross arm 100 along its length. The drive assembly 220 is used to drive the movable shaft 210 to reciprocate along its axial direction. A clamping block 230 (i.e., the movable end, which is integrally formed from a coaxial cylinder) is fixed to one end of the movable shaft 210 that extends into the notch 120. In the locked state, the drive assembly 220 pushes the movable shaft 210, causing the clamping block 230 to move to the front side of the semi-circular positioning groove 121 (i.e., the side facing the opening of the notch 120). At this time, the clamping block 230 and the groove wall of the semi-circular positioning groove 121 together form a C-shaped positioning cavity with an opening diameter smaller than the diameter of the positioning groove 121. The shank 330 of the cutter head 300 is firmly confined within this C-shaped positioning cavity. In practice, a stop protrusion 12a that can be inserted into the annular groove 331 on the shank 330 can be provided on the inner wall of the notch groove 120 to further enhance the longitudinal stability of the cutter head and prevent accidental slippage during movement.

[0039] To further optimize the locking effect and prevent the cutter head 300 from rotating within the C-shaped positioning cavity, the clamping block 230 is provided with a positioning plane 231 facing the shank 330. This positioning plane 231 is eccentrically positioned with respect to the axis of the movable shaft 210 and forms a certain angle (acute angle) with each other. In the locked state, when the clamping block 230 presses the shank 330 against the semi-circular positioning groove 121, the positioning plane 231 is exactly tangent to the peripheral wall of the shank 330, dispersing the clamping force on the shank 330 into two components: axial and radial. The resultant force of these two components passes through the axis of the shank 330 and extends to the inner wall of the notch 120, whose corresponding diameter points directly to it (the closer the point of action is to the diameter parallel to the width direction of the notch 120 and the cross arm 100, the better the locking effect), increasing the stability and friction of the locking.

[0040] The drive assembly 220 includes a drive shaft 221, a drive motor 222, and a transmission unit 223. The drive shaft 221 is coaxially arranged with the movable shaft 210 and is axially movable inside the cross arm 100. The movable shaft 210 has a slot 211 adapted to the drive shaft 221 at one end opposite to the positioning groove 121, and the inner wall of the slot 211 has an internal thread. The drive shaft 221 has an external thread adapted to the internal thread. The drive motor 222 is fixed to the lower surface of the cross arm 100 by a protective cover 224, and its rotating shaft 225 is vertically upward. A mounting groove 130 is provided on the lower surface of the cross arm 100 above the protective cover 224 for mounting the transmission unit 223. One end of the drive shaft 221 extends into the mounting groove 130 and is connected to the rotating shaft 225 of the drive motor 222 via the transmission unit 223. During operation, the drive motor 222 rotates, which drives the drive shaft 221 to rotate through the transmission unit 223. The external thread of the drive shaft 221 engages with the internal thread in the slot 211 of the movable shaft 210, converting the rotational motion into the linear motion of the movable shaft 210, thereby realizing the forward (locking) or backward (unlocking) movement of the abutment block 230.

[0041] The transmission unit 223 comprises a first bevel gear 226, a second bevel gear 227, and a connecting shaft 228. The first bevel gear 226 is coaxially fixed to the rotating shaft 225 of the drive motor 222, with its meshing surface (conical surface) facing upwards. The second bevel gear 227 meshes perpendicularly with the first bevel gear 226 (i.e., the axis of the second bevel gear 227 is perpendicular to and coplanar with the axis of the first bevel gear 226). The connecting shaft 228 is coaxially rotatably connected to the second bevel gear 227, and its end is horizontally rotatably connected to the upper end of the rotating shaft 225 via a bearing, thus providing a stable rotational support for the entire assembly of the second bevel gear 227 and the connecting shaft 228.

[0042] Furthermore, a spline is provided at the end of the drive shaft 221 facing the rotating shaft 225, which forms an axially separable sliding connection with the spline groove 229 on the end face of the second bevel gear 227 opposite to the rotating shaft 225 (circumferentially synchronously rotating, axially separable). In this way, the rotational power of the second bevel gear 227 can be transmitted to the drive shaft 221, while the drive shaft 221 can move axially relative to the second bevel gear 227 to facilitate assembly and disassembly. The drive shaft 221 and the second bevel gear 227 can be separated and disassembled (the former is inserted / exited from the notch groove, and the latter is inserted / exited synchronously from the mounting groove 130 with the motor and the first bevel gear 226).

[0043] In this embodiment, the tool changing mechanism also integrates a high-precision position calibration function. A first end-face cam 410 (cylindrical in shape with its driving surface located on its upper end face and forming an inclined annular slope) is coaxially fixed on the rotating shaft 225 and above the connecting shaft 228. Above the first end-face cam 410, a second end-face cam 420 (with the same structure as the first end-face cam 410 but with its driving surface facing downwards) is coaxially fixed to its upper end. A position positioning shaft 430 (closing the upper opening of the second end-face cam 420 and being integrally formed) is coaxially fixed to the upper end of the second end-face cam 420. The upper end of the position positioning shaft 430 extends through the mounting groove 130 on the upper surface of the cross arm 100 (the two are splined shaft-type assemblies to prevent rotation of the position positioning shaft 430). When the cross arm 100 rotates to the tool changing position, the synchronous action of the drive motor 222 drives the second end face cam 420 to rise via the first end face cam 410, thereby causing the position positioning shaft 430 to rise and precisely insert into the corresponding position calibration slot (not shown in the figure) at the lower end of the fixed vertical annular tool magazine. This mechanical insertion action can forcibly eliminate any minor accumulated errors that may occur during the long-term rotation of the cross arm 100, ensuring precise alignment between the clamping position 110 and the tool shank 330 (if insertion is not possible, the position sensor can detect the marker point on the positioning shaft 430 as feedback to send a reminder to the system).

[0044] To ensure the reliable operation of the calibration mechanism, a guide groove 131 is provided on the inner wall (top wall) of the mounting groove 130 to guide the up-and-down movement of the second end face cam 420. An elastic reset element 440, such as a spring, is provided within the guide groove 131. This elastic reset element 440 is sleeved on the position positioning shaft 430 and provides a downward elastic reset force to the second end face cam 420. A cover 450 is provided on the upper surface of the cross arm 100 to seal the elastic reset element 440 within the guide groove 131. The cover 450 has a through hole 451 through which the position positioning shaft 430 passes. When the drive motor 222 reverses, the first end face cam 410 disengages from the second end face cam 420. Under the action of the elastic reset element 440, the second end face cam 420 and the position positioning shaft 430 automatically descend and reset to exit the position calibration groove, thus avoiding obstruction of the cross arm 100's rotation.

[0045] Example 2 This embodiment is basically the same as Embodiment 1, and the similarities will not be repeated. The difference is that this embodiment also discloses a tool changing method for a dual-tool magazine vertical machine tool tool changing mechanism. This method fully utilizes the structural advantages of the mechanism in Embodiment 1, especially its built-in position calibration function, to achieve high-precision and high-reliability automatic tool changing. The method includes the following steps: Step 1: The system issues a tool change command, first controlling the vertical annular tool magazine to rotate the target tool head to be replaced inside to the exit end. At the same time, it controls the tool head spindle to move to the preset tool change point, so that the current tool head on the spindle and the tool head to be replaced at the exit end of the tool magazine are at the same horizontal height and their axes are parallel to each other, preparing for the horizontal arm to grasp.

[0046] Step 2: Drive the horizontal arm to rotate horizontally to the initial tool change position. Through precise control, ensure that the clamping positions at both ends of the horizontal arm are directly aligned with the tool shank on the spindle and the tool shank at the tool magazine exit end, respectively.

[0047] Step 3: Initiate the position calibration program. At this time, the drive motor continues to rotate slowly, driving the second end-face cam to rise against the elastic force of the spring-loaded reset element via the first end-face cam. This causes the position positioning axis to move upwards until it is precisely inserted into the corresponding position calibration slot at the lower end of the vertical annular tool magazine. This mechanical hard positioning eliminates any accumulated errors that may exist in the crossarm rotation drive system, ensuring precise alignment between the clamping position and the tool shank, providing positional assurance for the subsequent tool locking action.

[0048] Step 4: After the position is calibrated, the drive motor continues to operate, driving the drive shafts of the two cutter head locking modules to rotate via the transmission unit. The drive shafts, through a threaded connection, drive the movable shaft to extend along the length of the horizontal arm, causing the clamping blocks to move towards the semi-circular positioning grooves. Finally, the clamping blocks clamp the shanks of the two cutter heads into their respective semi-circular positioning grooves, forming a stable C-shaped lock. At this point, the two cutter heads are firmly gripped by the horizontal arm.

[0049] Step 5: After confirming that the tool head is locked by the cross arm, the control system issues a command. The tool head clamping mechanism on the spindle releases its grip on the current tool head, and at the same time, the clamping mechanism at the tool magazine's output end also releases its grip on the tool head to be replaced. Subsequently, the control system moves the spindle and tool magazine's movement mechanisms backward a preset distance along the axial direction, ensuring that both tool heads are completely removed from their original mounting positions. At this point, the tool heads are only supported and fixed by the clamping position of the cross arm.

[0050] Step Six: Drive the cross arm to rotate smoothly 180 degrees around its center of rotation. This action swaps the positions of the tool head that was originally on the spindle and the tool head at the tool magazine exit end.

[0051] Step 7: After the cross arm rotates to its final position, control the spindle and tool magazine to move axially back to their previous gripping positions. At this point, the swapped tool head shanks will accurately insert into the spindle taper hole and the tool magazine's exit clamping hole, respectively. Subsequently, the clamping mechanisms of the spindle and tool magazine will reactivate, clamping the two tool heads respectively.

[0052] Step 8: After confirming that the cutter head has been reliably clamped by the spindle and tool magazine, drive the motor to rotate in the opposite direction. This drives the movable shaft to retract via the transmission mechanism, causing the retaining block to move backward, releasing the lock on the two cutter head shanks, and completely disengaging the cross arm from the cutter head.

[0053] Step Nine: The drive motor continues to reverse, disengaging the first end face cam from the second end face cam. Under the action of the elastic reset component, the position positioning shaft automatically descends, disengaging from the tool magazine's calibration slot. Finally, the drive arm rotates in the opposite direction, returning to the initial waiting position, awaiting the next tool change command. This completes one high-precision tool change cycle.

[0054] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A tool changing mechanism for a dual-tool magazine vertical machine tool, assembled at the lower end of the vertical annular tool magazine of the dual-tool magazine vertical machine tool, used to interchange the positions of the tool heads at the magazine exit end of the vertical annular tool magazine and on the tool head spindle, characterized in that, include: A horizontal arm is rotatably mounted below the vertical annular tool magazine and has clamping positions for holding tool heads at both ends. It is configured to interchange the positions of the tool heads at the magazine exit end and the tool head spindle. The cutter head locking module has two corresponding clamps and is configured to lock or unlock the cutter head at the clamping position; The movable end of the blade locking assembly is located inside the cross arm and extends through the clamping position, and cooperates with it to lock or unlock the handle of the blade.

2. The tool changing mechanism for a vertical machine tool with a dual-tool magazine according to claim 1, characterized in that, The end sidewall of the cross arm has a notch, and the sidewall of the notch along the width direction of the cross arm has a semi-circular positioning groove for the shank of the positioning cutter head, and the positioning groove travels to the clamping position; the movable end of the cutter head locking module extends out of the notch along the length direction of the cross arm.

3. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 2, characterized in that, The cutter head locking module includes a movable shaft that is movably arranged along the length direction of the horizontal arm, and a drive assembly that drives the movable shaft to reciprocate along a fixed axis; one end of the movable shaft that extends into the notch is fixed with a clamping block for pressing the shank against the side wall of the positioning groove; in the locked state, the clamping block is located on the front side of the positioning groove and surrounds it to form a C-shaped positioning cavity with an opening diameter smaller than the diameter of the positioning groove.

4. The tool changing mechanism for a vertical machine tool with a dual-tool magazine according to claim 3, characterized in that, The positioning block is provided with a positioning plane facing the handle. The positioning plane is eccentrically set with respect to the axis of the movable shaft. In the locked state, the positioning plane is tangent to the peripheral wall of the handle.

5. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 3, characterized in that, The drive assembly includes a drive shaft coaxial with the movable shaft and axially movable within the cross arm, a drive motor for driving the drive shaft to rotate on a fixed axis, and a transmission unit for driving the drive motor and the drive shaft; the end of the movable shaft opposite to the positioning groove is provided with a slot adapted to the drive shaft, the inner wall of the slot is provided with an internal thread, and the drive shaft is provided with an external thread adapted to the internal thread.

6. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 3, characterized in that, The drive motor shaft is vertically upward, and the drive motor is fixed to the lower surface of the cross arm by a protective cover; the lower surface of the cross arm is provided with a mounting groove for mounting the transmission unit above the protective cover, and the drive shaft extends into the mounting groove and is connected to the drive motor shaft through the transmission unit.

7. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 6, characterized in that, The transmission unit includes a first bevel gear coaxially fixed on the rotating shaft with its meshing surface facing upward, a second bevel gear meshing perpendicularly with the first bevel gear, and a connecting shaft rotatably connected to the second bevel gear coaxially; one end of the connecting shaft facing the rotating shaft is horizontally rotatably connected to the rotating shaft via a bearing; the drive shaft is axially separable from the second bevel gear via a spline groove provided on the end face of the second bevel gear.

8. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 7, characterized in that, A first end face cam is coaxially fixed on the rotating shaft above the connecting shaft. A second end face cam is coaxially engaged with the first end face cam above it. A position positioning shaft is coaxially provided at the upper end of the second end face cam. The upper end of the position positioning shaft extends out of the mounting groove. When the position positioning shaft rises to its position, it is inserted into the position calibration groove at the lower end of the vertical annular tool magazine to eliminate the rotational accumulation error of the cross arm.

9. The tool changing mechanism for a vertical machine tool with a double tool magazine according to claim 8, characterized in that, The inner wall of the mounting groove is provided with a guide groove for guiding the up and down movement of the second end face cam. The guide groove is provided with an elastic reset member that provides a downward elastic reset force to the second end face cam. The upper surface of the cross arm is provided with a cover that seals the elastic reset member in the guide groove. The cover is provided with a through hole for the position positioning shaft to pass through.

10. A tool changing method for a tool changing mechanism of a dual-tool magazine vertical machine tool, as described in claim 8, characterized in that, The method includes the following steps: Step 1: Rotate the tool head to be replaced in the vertical ring tool magazine to the exit end, and move the tool head spindle to the preset tool changing position so that the current tool head on the spindle and the tool head to be replaced at the exit end of the tool magazine are at the same horizontal height and their axes are parallel to each other. Step 2: Drive the horizontal arm to rotate horizontally to the initial tool change position, so that the clamping positions at both ends of the horizontal arm are directly opposite the tool head shank on the spindle and the tool head shank at the tool magazine exit end, respectively. Step 3: Activate the position calibration mechanism to drive the position positioning shaft to rise and insert it into the corresponding position calibration slot at the lower end of the vertical ring tool magazine, so as to eliminate the positioning error accumulated by the long-term rotation of the cross arm and ensure the precise alignment of the clamping position with the tool head shank. Step 4: Drive the two cutter head locking modules to move simultaneously, so that their movable ends extend along the length of the horizontal arm, locking the shanks of the two cutter heads in their corresponding clamping positions. Step 5: Control the spindle to release the clamp on the current tool head, and at the same time control the tool magazine to release the clamp on the tool head to be replaced. Control the spindle and tool magazine to move backward a preset distance along the axis respectively, so that the two tool heads are completely disengaged and only held by the cross arm. Step 6: Drive the cross arm to rotate 180 degrees around its center of rotation, and interchange the positions of the two cutter heads; Step 7: Control the spindle and tool magazine to move axially to reset, so that the exchanged tool head shanks are accurately inserted into the spindle taper hole and the tool magazine exit end clamping hole respectively, and then re-clamp them; Step 8: Drive the cutter head locking module to reverse its movement, causing its movable end to retract and release the lock on the two cutter head shanks; Step 9: Drive the position positioning axis to descend and disengage from the calibration slot, and drive the cross arm to rotate in the opposite direction to return to the initial waiting position, completing one tool change cycle.

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