Tool changing main shaft assembly adopting tool changing deviation correction structure

Abstract

The invention discloses a tool changing main shaft assembly adopting a tool changing deviation correction structure, relates to the technical field of machine tools, and aims to improve a tool changing arm on the basis of a conventional tool handle and a machine tool operation principle without changing a tool handle structure, and the tool changing main shaft assembly is essentially characterized in that a tool handle grabbing mode in two actions of tool taking and tool changing is improved; a movable clamping jaw is matched with concave opening clamping positions at the two ends of a tool changing arm to achieve the fixed grabbing action of a tool holder, the key point is that an upper pin opening of the tool holder serves as a basic structure, an inner lifting pin and an outer lifting pin are additionally arranged in a matched mode, the inner lifting pin is used for maintaining the basic position of the tool holder in a tool magazine, and the outer lifting pin is matched with the tool changing action of the tool holder in a machine head on a CNC machining center. In the whole tool changing process, the position of a tool handle in a machine head on a CNC machining center is used as the basis, feedback control is conducted in combination with air pressure data, the relative position of the tool handle in a tool magazine is directly guaranteed, and the position deviation in the follow-up tool installing action is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of machine tools, and in particular to a tool-changing spindle assembly adopting a tool-changing offset correction structure. Background Art

[0002] The automatic tool change magazine in the five-axis CNC is to realize automatic tool change by using the automatic tool change device (mechanical arm) and pallet (tool disc) in accordance with the production requirements. Please refer to the relevant content in the publication number CN106736786A. The key structure is the tool handle, which needs to be coordinated with the automatic tool change requirements to perform actions such as unloading, placing, and reloading the tool. At present, the simplest and most effective one is the tool change arm. Please refer to the relevant content in the publication number CN110039353A.

[0003] It should be noted that: during the continuous operation of the machine tool, electrical failures (unstable air pressure), program errors and other problems may affect three positions in the tool changing process. Specifically, the "quality" of reinstalling the tool and the relative position after placing the tool are one of the key factors affecting subsequent processing. If there is a deviation in the position of reinstalling the tool, it will directly affect the subsequent processing accuracy, and if there is a deviation in the position of placing the tool, it will also affect the action of reinstalling the tool. Conventional tool changing arms cannot perceive the position deviation in real time, which may affect the subsequent processing accuracy and even cause serious safety accidents such as tool dropping and tool collision.

[0004] This application proposes a solution to this problem. Summary of the invention

[0005] The purpose of the present invention is to provide a tool changing spindle assembly with a tool changing deviation correction structure, which is aimed at the tool changing method in the tool changing magazine of a machine tool, because electrical failures, program errors and other problems directly affect the relative position during the tool changing process, directly affect the subsequent processing accuracy and even cause safety accidents.

[0006] The object of the present invention can be achieved through the following technical solutions: a tool change spindle assembly adopting a tool change deviation correction structure is used in a CNC machining center, comprising a tool magazine drive assembly, a tool change arm and an intermediate drive assembly, wherein the tool magazine drive assembly is provided with a tool handle tray assembly, the tool change arm is located in the middle position between the tool handle tray assembly and the head position on the CNC machining center, and the end of the output shaft of the intermediate drive assembly is fixedly connected to the middle position of the tool change arm;

[0007] The tool handle tray assembly is provided with a plurality of tool handle bodies, and the tool change arm is provided with notch clamping positions corresponding to the tool handle bodies at both ends, and a movable clamping claw is provided at the position of the tool change arm corresponding to the notch clamping position;

[0008] An upper cylinder and a lower cylinder are respectively installed on the upper and lower surface positions of the tool changing arm corresponding to the notch clamping position, an external ejector pin is installed on the end position of the output shaft of the upper cylinder, the end of the output shaft of the lower cylinder is connected to a movable clamping claw, and the movable clamping claw is slidably connected to the tool changing arm through the lower cylinder, and a control system associated with the upper cylinder and the lower cylinder is provided in the CNC machining center.

[0009] It is further configured as follows: the tool handle bodies are arranged in a circular array along the center point position of the tool handle tray assembly, and the tool handle bodies are numbered in a clockwise or counterclockwise direction through a control system.

[0010] It is further configured as follows: a clamping claw assembly corresponding to the handle body is arranged on the handle tray assembly, the clamping claw assembly is composed of two outer claws and a connecting spring, the midpoint of the outer claw is rotationally connected to the handle tray assembly, and the connecting spring is installed at one end of the two outer claws close to the center point of the handle tray assembly.

[0011] It is further configured that: an inner ejector pin corresponding to the tool handle body is installed on the upper surface of the tool handle tray assembly.

[0012] It is further configured as follows: an inner slide groove corresponding to the movable clamping claw is opened inside the tool changing arm, and the setting direction of the inner slide groove is parallel to the length direction of the tool changing arm.

[0013] It is further configured that: the bending directions of the two movable clamping jaws along the width direction of the tool changing arm are opposite.

[0014] It is further configured that: a plurality of inner balls are arranged on the inner wall position of the movable clamping jaw and the outer wall position of the notch clamping position.

[0015] It is further configured that: the lower side surface of the outer ejector pin along the direction close to the handle body is in the shape of an inclined curved surface.

[0016] It is further configured that: the tool changing spindle assembly is configured with the following actions through the control system:

[0017] Tool taking action: one end of the tool changing arm is moved close to the tool holder tray assembly through the tool magazine drive assembly and the intermediate drive assembly, and the tool holder body at the corresponding numbered position is taken out through the clamp assembly;

[0018] Tool changing action: Tool changing action and tool taking action can be performed synchronously. The air pressure data in the upper cylinder is recorded in real time through the control system, and the air pressure data is used to provide action feedback to the upper head of the CNC machining center;

[0019] Tool loading action: After completing the tool removal action and tool changing action, the tool changing arm rotates 180° clockwise or counterclockwise to perform tool loading actions at two positions respectively.

[0020] The present invention has the following beneficial effects:

[0021] 1. The overall structure is applied to the tool changing process in the CNC machining center. The overall process will not change the tool handle structure, but will improve the tool change arm structure based on the conventional tool handle structure and the working principle of the machine tool. Its essence is to improve the gripping method of the tool handle in the two actions of picking up and changing the tool, and to realize the fixed gripping action of the tool handle by using the movable clamping claws in conjunction with the notch clamping positions at both ends of the tool change arm. The gripping position is located at the lower side of the tool handle, and an inner ejector pin and an outer ejector pin are added during the gripping process. The inner ejector pin is used to maintain the basic position of the tool handle in the tool magazine, while the outer ejector pin is used to cooperate with the tool change action of the tool handle in the upper head of the CNC machining center to ensure the accuracy of the gripping position.

[0022] 2. In combination with the above content, it should be explained that: during the movement of the inner and outer ejector pins added to cooperate with the picking action, the tool holder body will produce air pressure changes. Therefore, the overall tool change is based on the position of the tool holder in the head of the CNC machining center, combined with the air pressure data for feedback control, which directly ensures the relative position of the tool holder in the tool magazine, thereby avoiding position deviation in the subsequent tool installation action. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of a tool changing spindle assembly using a tool changing misalignment correction structure proposed by the present invention;

[0025] Figure 2 A schematic structural diagram of a tool handle tray assembly in a tool changing spindle assembly using a tool changing misalignment correction structure proposed by the present invention;

[0026] Figure 3 The present invention proposes a tool changing spindle assembly with a tool changing offset correction structure. Figure 2 A top view of

[0027] Figure 4 A schematic diagram of the structure of a clamping jaw assembly in a tool changing spindle assembly adopting a tool changing deviation correction structure proposed by the present invention;

[0028] Figure 5 A schematic diagram of the structure of a tool changing arm in a tool changing spindle assembly adopting a tool changing offset correction structure proposed by the present invention;

[0029] Figure 6 The present invention proposes a tool changing spindle assembly with a tool changing offset correction structure. Figure 5 A partial cutaway view of

[0030] Figure 7 The present invention proposes a tool changing spindle assembly with a tool changing offset correction structure. Figure 5 Bottom view of .

[0031] In the figure: 1. tool magazine drive assembly; 2. intermediate drive assembly; 3. tool changing arm; 4. tool holder tray assembly; 5. tool holder body; 6. clamping jaw assembly; 7. connecting spring; 8. inner ejector pin; 9. movable clamping jaw; 10. outer ejector pin; 11. upper cylinder; 12. inner slide groove; 13. inner ball bearing; 14. lower cylinder. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1: With regard to the tool changing method in the tool changing magazine of a machine tool, because electrical failures, program errors and other problems directly affect the relative position during the tool changing process, directly affect the subsequent processing accuracy and even cause safety accidents, the following technical solutions are proposed:

[0034] Reference Figures 1 to 6 In this embodiment, a tool change spindle assembly adopting a tool change deviation correction structure is used in a CNC machining center, and includes a tool magazine drive assembly 1, a tool change arm 3 and an intermediate drive assembly 2. A tool handle tray assembly 4 is provided on the tool magazine drive assembly 1. The tool change arm 3 is located in the middle position between the tool handle tray assembly 4 and the head position on the CNC machining center. The end of the output shaft of the intermediate drive assembly 2 is fixedly connected to the middle position of the tool change arm 3.

[0035] A plurality of tool handle bodies 5 are arranged on the tool handle tray assembly 4, and recessed clamping positions corresponding to the tool handle bodies 5 are provided at both ends of the tool changing arm 3, and movable clamping claws 9 are arranged at positions of the tool changing arm 3 corresponding to the recessed clamping positions;

[0036] An upper cylinder 11 and a lower cylinder 14 are respectively installed on the upper and lower surface positions of the tool changing arm 3 corresponding to the notch clamping position, an outer ejector pin 10 is installed on the end position of the output shaft of the upper cylinder 11, and the end of the output shaft of the lower cylinder 14 is connected to the movable clamping claw 9, and the movable clamping claw 9 is slidably connected to the tool changing arm 3 through the lower cylinder 14. A control system associated with the upper cylinder 11 and the lower cylinder 14 is provided in the CNC machining center, and the tool handle body 5 is arranged in a circular array along the center point position of the tool handle tray assembly 4, and the tool handle body 5 is numbered in a clockwise or counterclockwise direction through the control system;

[0037] The tool-changing spindle assembly is set to the following actions through the control system:

[0038] Tool taking action: one end of the tool changing arm 3 is positioned close to the tool handle tray assembly 4 through the tool magazine drive assembly 1 and the intermediate drive assembly 2, and the tool handle body 5 at the corresponding numbered position is taken out through the clamp assembly 6;

[0039] Tool changing action: Tool changing action and tool taking action can be performed synchronously. The air pressure data in the upper cylinder 11 is recorded in real time by the control system, and the air pressure data is used to provide action feedback to the upper machine head of the CNC machining center;

[0040] Tool loading action: After completing the tool taking action and tool changing action, the tool changing arm 3 rotates 180° clockwise or counterclockwise to perform tool loading actions at two positions respectively.

[0041] Solution Description: For the CNC machining center structure and its matching tool structure, the structure and appearance are relatively fixed, so the tool handle structure is not improved in the present invention. Figure 4 The tool handle body 5 is the basis, wherein the tool handle tray assembly 4 is used to represent the related structure for placing the tool handle body 5, the tool magazine drive assembly 1 drives the tool handle tray assembly 4 to rotate or move linearly, wherein the tool change arm 3 is the key structure for grabbing the tool handle body 5, and the intermediate drive assembly 2 drives the tool change arm 3 to rotate or move linearly;

[0042] Further understand: Figure 1Taking the positional relationship in as an example, when one end of the tool changing arm 3 is close to the tool handle tray assembly 4 or the upper head of the CNC machining center, the lower cylinder 14 is firstly injected / exhausted to make the movable clamp 9 relatively away from the notch clamping position. After ensuring that the notch clamping position is in contact with the tool handle body 5, the movable clamp 9 is moved in the opposite direction again, so that the tool handle body 5 is initially fixed by the movable clamp 9, and then the tool handle body 5 is removed from the tool handle tray assembly 4 or the upper head of the CNC machining center, and the tool changing arm 3 is rotated 180° clockwise or counterclockwise, and the tool handle body 5 removed from the upper head of the CNC machining center is placed on the tool handle tray assembly 4, or the tool handle body 5 removed from the tool handle tray assembly 4 is reinstalled on the upper head of the CNC machining center. This part is the basic content of the present invention.

[0043] Embodiment 2: Explanation of the tool handle tray assembly in Embodiment 1:

[0044] The tool handle tray assembly 4 is provided with a clamping claw assembly 6 corresponding to the tool handle body 5. The clamping claw assembly 6 consists of two outer claws and a connecting spring 7. The midpoint of the outer claw is rotationally connected to the tool handle tray assembly 4. The connecting spring 7 is installed at one end of the two outer claws close to the center point of the tool handle tray assembly 4. The inner top pin 8 corresponding to the tool handle body 5 is installed on the upper surface of the tool handle tray assembly 4.

[0045] Solution Description: This example refers to Figure 2 , Figure 3 and Figure 4 , the tool handle body 5 is installed by the clamping force of the two outer claws, which can be understood as follows: after the tool change arm 3 fixes the tool handle body 5 at the corresponding numbered position through the movable clamping claw 9, and because the two outer claws provide clamping force through the elastic action of the connecting spring 7, the tool change arm 3 can be driven by the intermediate driving assembly 2 to move linearly in the direction away from the tool handle tray assembly 4, so the tool handle body 5 can be removed from the clamping claw assembly 6 at the corresponding position;

[0046] On the contrary, when the tool handle body 5 removed from the upper head of the CNC machining center is placed on the tool handle tray assembly 4, the tool handle body 5 can also be directly "squeezed" into the clamping jaw assembly 6 through the linear movement of the tool changing arm 3.

[0047] Embodiment 3: Explanation of the grabbing action of the tool change arm on the tool handle body in Embodiment 1:

[0048] An inner slide groove 12 corresponding to the movable clamping jaw 9 is opened inside the tool changing arm 3, and the setting direction of the inner slide groove 12 is parallel to the length direction of the tool changing arm 3. The two movable clamping jaws 9 are bent in opposite directions along the width direction of the tool changing arm 3. A plurality of inner balls 13 are arranged on the inner wall position of the movable clamping jaw 9 and the outer wall position of the notch clamping position, and the lower side surface of the outer ejector pin 10 along the direction close to the tool handle body 5 is in the shape of an inclined curved surface.

[0049] First, combined with the operating principle of the CNC machining center, the overall tool changing process is explained as follows:

[0050] S1: Because the tool holder tray assembly 4 is used as a tool magazine structure and is fixed only by the clamping force in the clamping jaw assembly 6, the key to the overall tool changing process is to remove the tool holder from the upper head of the CNC machining center and to install the tool holder body 5 on the head of the CNC machining center. Explain: After the tool holder body 5 is clamped by hydraulic or pneumatic means, it is necessary to ensure that the tool holder body 5 keeps rotating. The pin groove position on the tool holder body 5 is a key structure. Therefore, when the tool holder body 5 is re-placed on the tool holder tray assembly 4, it is first necessary to clamp one of the pin groove positions with the inner ejector pin 8. Therefore, it is only necessary to ensure that the position relationship in the action is changed;

[0051] S2: Combined with S1, during the operation of the CNC machining center, the drill speed is very fast, so it is difficult to ensure the relative position of the pin groove in the tool handle body 5. Before the movable clamp 9 in the tool changing arm 3 initially fixes the tool handle body 5 on the machine head position, the outer ejector pin 10 is first driven by the upper cylinder 11 to move linearly in the direction close to the tool handle body 5. In this process, it should be noted that if the pin groove position on the tool handle body 5 does not match, the outer ejector pin 10 cannot continue to move. When the upper cylinder 11 is continuously injected with air, the air pressure of the outer ejector pin 10 continues to increase because the outer ejector pin 10 cannot move. Thus, it is fed back that the position of the tool handle body 5 in the upper machine head of the CNC machining center is deviated. For this, it is necessary to control the machine head to move slowly in a clockwise or counterclockwise direction until the pin groove position on the tool handle body 5 is aligned with the outer ejector pin 10, and the outer ejector pin 10 can continue to move. After the outer ejector pin 10 continues to move for a distance, it cannot move further, which can directly indicate that the position of the tool handle body 5 on the machine head is in a normal position. Finally, the lower cylinder 14 drives the movable clamping claw 9 to fix the tool handle body 5, and rotates it 180° in the opposite direction to place the tool handle body 5 back in the tool handle tray assembly 4.

[0052] S3: It should also be noted that: when taking out the tool handle body 5 on the tool handle tray assembly 4, it is also necessary to synchronously utilize the linear movement process of the outer push pin 10, which is specifically expressed as: after the upper cylinder 11 at that position is pressurized to move the outer push pin 10 for a certain distance until it can no longer move, it can be indicated that the tool changing arm 3 completes the positioning action of the tool handle body 5 on the tool handle tray assembly 4, and finally the tool handle body 5 is synchronously fixed and taken out with the movable clamp 9.

[0053] Combined with the above S1~S3, the overall tool changing process is based on linear movement, and the total length of the tool changing arm 3 can be measured, so that only the linear movement distance of the tool changing arm 3 can be limited, and the air pressure changes in S2 or S3 can be coordinated to ensure that the notch clamp on the tool changing arm 3 is completely in contact with the tool handle body 5, and the relative angle of the tool handle body 5 when fixed is ensured.

[0054] In summary: without changing the structure of the tool holder, the tool changing arm is improved based on the conventional tool holder and the operating principle of the machine tool. The essence of this improvement is to improve the way of grasping the tool holder in the two actions of tool picking and tool changing, and to realize the fixed grasping action of the tool holder by cooperating with the recessed clamping positions at both ends of the tool changing arm with the movable clamping claw. The key is to use the basic structure of the pin mouth on the tool holder with the addition of inner and outer ejector pins. The inner ejector pin is used to maintain the basic position of the tool holder in the tool magazine, while the outer ejector pin is used to cooperate with the tool changing action of the tool holder in the upper head of the CNC machining center. The overall tool changing is based on the position of the tool holder in the upper head of the CNC machining center, and is combined with the air pressure data for feedback control to directly ensure the relative position of the tool holder in the tool magazine, thereby avoiding position deviation in subsequent tool installation actions.

[0055] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0057] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A tool changing spindle assembly with a tool changing offset correction structure, used in a CNC machining center, comprising a tool magazine drive assembly (1), a tool changing arm (3) and an intermediate drive assembly (2), characterized in that: The tool magazine drive assembly (1) is provided with a tool handle tray assembly (4), the tool change arm (3) is located in the middle position between the tool handle tray assembly (4) and the head position of the CNC machining center, and the output shaft end of the intermediate drive assembly (2) is fixedly connected to the middle position of the tool change arm (3); The tool handle tray assembly (4) is provided with a plurality of tool handle bodies (5), and recessed clamping positions corresponding to the tool handle bodies (5) are provided at both ends of the tool changing arm (3), and movable clamping claws (9) are provided at positions of the tool changing arm (3) corresponding to the recessed clamping positions; An upper cylinder (11) and a lower cylinder (14) are respectively installed on the upper and lower surface positions of the tool changing arm (3) corresponding to the notch clamping position, an outer ejector pin (10) is installed on the end position of the output shaft of the upper cylinder (11), the end of the output shaft of the lower cylinder (14) is connected to a movable clamping claw (9), and the movable clamping claw (9) is slidably connected to the tool changing arm (3) through the lower cylinder (14), and a control system for associating the upper cylinder (11) and the lower cylinder (14) is provided in the CNC machining center; The handle bodies (5) are arranged in a circular array along the center point of the handle tray assembly (4), and the handle bodies (5) are numbered in a clockwise or counterclockwise direction by a control system, and an inner ejector pin (8) corresponding to the handle body (5) is installed on the upper surface of the handle tray assembly (4).

2. The tool changing spindle assembly with a tool changing offset correction structure according to claim 1, characterized in that: The tool handle tray assembly (4) is provided with a clamping claw assembly (6) corresponding to the tool handle body (5), the clamping claw assembly (6) is composed of two outer claws and a connecting spring (7), the midpoint of the outer claw is rotatably connected to the tool handle tray assembly (4), and the connecting spring (7) is installed at one end of the two outer claws close to the center point of the tool handle tray assembly (4).

3. The tool changing spindle assembly with a tool changing deviation correction structure according to claim 1, characterized in that: An inner slide groove (12) corresponding to the movable clamping claw (9) is provided inside the tool changing arm (3), the setting direction of the inner slide groove (12) is parallel to the length direction of the tool changing arm (3), the bending directions of the two movable clamping claws (9) along the width direction of the tool changing arm (3) are opposite, and a plurality of inner balls (13) are provided on the inner wall position of the movable clamping claw (9) and the outer wall position of the notch clamping position.

4. The tool changing spindle assembly with a tool changing offset correction structure according to claim 1, characterized in that: The lower side surface of the outer ejector pin (10) in the direction close to the handle body (5) is in the shape of an inclined curved surface.

5. A tool changing spindle assembly with a tool changing offset correction structure according to any one of claims 1 to 4, characterized in that: The tool changing spindle assembly is set to the following actions through the control system: Tool removal action: one end of the tool change arm (3) is moved close to the tool handle tray assembly (4) through the tool magazine drive assembly (1) and the intermediate drive assembly (2), and the tool handle body (5) at the corresponding numbered position is removed through the clamping claw assembly (6); Tool changing action: The tool changing action and the tool taking action can be performed synchronously. The air pressure data in the upper cylinder (11) is recorded in real time by the control system, and the air pressure data is used to provide action feedback to the upper machine head of the CNC machining center; Tool loading action: After completing the tool removal action and tool changing action, the tool changing arm (3) rotates 180° clockwise or counterclockwise to perform tool loading actions at two positions respectively.

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