Power head middle hydraulic rapid clamping tool changing device and method

Abstract

The invention discloses a power head middle hydraulic rapid clamping tool changing device which comprises a power head and a tool turret, the power head comprises a tool bit and a main shaft, and the main shaft is sleeved with a piston, a circular ring piece, an outer ring step piece, an inner ring step piece and a disc piece; one end, close to the tool turret, of the piston is arranged opposite to the circular ring piece to form a first hydraulic gap, and the other end of the piston forms a second hydraulic gap; the piston is sleeved with the circular ring piece, and the circular ring piece abuts against the position between the piston and the tool turret. The main shaft is sleeved with the inner ring step part and the disc part together, the inner ring step part is fixedly connected with the rear end of the piston, and the inner ring step part is sleeved with the outer ring step part and fixedly connected with the disc part; a movable rod, an elastic element and a connecting column are arranged in the main shaft, the movable rod is sleeved with the elastic element, the top end of the elastic element abuts against a limiting structure in the main shaft, the bottom end of the elastic element abuts against a boss on the movable rod, and the bottom end of the movable rod abuts against the inner bottom face of the main shaft in the natural state.

Description

Technical Field

[0001] This invention relates to the field of tool changing technology for CNC machine tools, and particularly to a hydraulic quick clamping and tool changing device and method in the middle of the power head. Background Technology

[0002] In CNC machine tools, especially high-end equipment such as mill-turn machining centers, automatic, rapid, and precise tool changing of the power head is a core function to ensure machining efficiency and accuracy. Currently, mainstream automatic tool changers all have significant shortcomings, mainly manifested in technical problems such as complex structure, slow response, and low precision.

[0003] Therefore, there is an urgent need for a highly integrated tool changer that can achieve fast, accurate, automatic, and efficient reset, and enable a reliable automated tool change process. Summary of the Invention

[0004] One of the objectives of this invention is to provide a hydraulic quick-clamping and tool-changing device in the middle of the power head, so as to solve the problems of complex structure, slow response and low accuracy of existing tool-changing devices.

[0005] Another objective of this invention is to provide a rapid tool changing method based on the above-mentioned device, so as to achieve an efficient, accurate and reliable automated tool changing process.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A hydraulic quick-clamping and tool-changing device in the middle of a power head includes a power head and a tool turret. The power head is fixedly connected to the tool turret. The power head includes a tool head and a spindle connected inside the tool head. A piston, a circular ring, an outer ring stepped component, an inner ring stepped component, and a disc are sequentially sleeved on the outside of the spindle. The piston is sleeved on the outside of the spindle, with one end near the tool turret opposite the circular ring to form a first hydraulic gap, and the other end forming a second hydraulic gap. The circular ring is sleeved on the outside of the piston and abuts against the piston and the tool turret. The inner ring stepped component and the disc are together sleeved on the spindle. Externally, the inner ring stepped component is fixedly connected to the rear end of the piston, and the outer ring stepped component is sleeved on the outside of the inner ring stepped component and fixedly connected to the disc component. The main shaft is internally provided with a movable rod, an elastic element, and a connecting column. The elastic element is sleeved on the outside of the movable rod, with its top end abutting against the limiting structure inside the main shaft and its bottom end abutting against the boss on the movable rod, so that the bottom end of the movable rod abuts against the inner bottom surface of the main shaft in its natural state. The connecting column passes through the disc component and the movable rod in sequence, and passes through the avoidance structure provided on the main shaft for axial movement, so that the disc component and the movable rod can move synchronously.

[0007] Furthermore, sealing grooves are provided on the outer walls of both the piston and the annular component, and sealing elements are provided in the sealing grooves.

[0008] Furthermore, the annular component has a protrusion on the end face opposite to the piston.

[0009] Furthermore, the inner ring step member is provided with a flange, and the outer ring step member is provided with a corresponding groove, and the flange and the groove are engaged; in the initial state and during the working stroke, at least one working surface of the flange is in contact with the corresponding side wall of the groove to transmit axial force; when the piston moves backward to abut against the protrusion, the inner ring step member is driven by the piston to generate an axial displacement relative to the outer ring step member, so that the flange and the groove are disengaged from each other in the axial direction, and an axial gap is formed between the inner ring step member and the disc member.

[0010] Furthermore, the groove size on the outer ring step is larger than the flange size on the inner ring step.

[0011] Furthermore, the connecting column, movable rod, and disc are all fixedly connected.

[0012] Furthermore, the clearance structure on the side wall of the main shaft for axial movement of the connecting column is an axially extending track groove.

[0013] A rapid tool changing method based on the above-mentioned device includes the following steps: S1. Inject hydraulic oil into the first hydraulic gap, and the hydraulic oil pushes the piston to move forward along the main shaft; S2. The piston drives the inner ring stepped component, which is fixedly connected to it, to move forward together. The inner ring stepped component, through the contact and cooperation between its flange and the groove on the outer ring stepped component, pulls the outer ring stepped component forward. The outer ring stepped component drives the disc component, which is fixedly connected to it, to move forward. S3. The disc component pulls the movable rod forward through the connecting column and compresses the elastic element. The tool holder connected to the front end of the movable rod moves forward synchronously until it is connected to the tool assembly port and the docking is completed.

[0014] Furthermore, it also includes a pressure relief and reset step: S4. After the docking assembly is completed, the device is depressurized, the preload of the elastic element is released, and the movable rod is pushed to move backward. S5. The movable rod drives the disc component and the outer ring step component to move backward together through the connecting column; S6. The outer ring stepped component, through the contact and engagement of the groove and the flange, pulls the inner ring stepped component and the piston to move backward and reset together, thereby locking the tool after tool change.

[0015] Furthermore, it also includes a rotational separation step: S7. Inject hydraulic oil into the second hydraulic gap to push the piston to continue moving backward along the main shaft; S8. The piston drives the inner ring stepped component to move backward synchronously until the piston abuts against the protrusion on the ring component. S9. Under the limiting action of the protrusion, the flange on the inner ring step and the groove on the outer ring step change from abutting to disengaging, and a gap is formed between the inner ring step and the disc, so that the outer ring step and the disc can rotate with the main shaft without interference.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By sequentially and coaxially mounting core drive components such as pistons, ring parts, outer ring stepped parts, inner ring stepped parts, and disc parts on the outside of the spindle, and linking them with the internal moving rods through connecting columns, a highly integrated hydraulic-mechanical drive chain is constructed, which greatly shortens the power transmission path and enables rapid response in tool clamping and changing actions.

[0017] 2. Utilizing the energy stored in the pre-compressed elastic element, the entire drive chain can be automatically and accurately reset to its initial position after hydraulic depressurization, without the need for an additional power source and control, simplifying the system and ensuring repeatability accuracy.

[0018] 3. Through the mating structure of the flange and groove and the limiting effect of the protrusion, the reliable engagement of the drive component and the rotating component during operation and the complete physical separation during high-speed rotation are achieved, forming an axial clearance, avoiding frictional interference, and improving the accuracy and life of the spindle. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the quick-clamping and tool-changing device of the present invention; Figure 2 This is a schematic cross-sectional view of the quick clamping and tool changing device of the present invention in the state of performing rotational separation and clamping. Figure 3 for Figure 2 A magnified schematic diagram of the local structure; Figure 4 This is a three-dimensional structural diagram of the power head of the present invention; Figure 5 This is a side view of the power head structure of the present invention; Figure 6 This is a schematic diagram of the disassembled assembly structure of the power head of the present invention; Figure 7 This is a schematic diagram showing the state during the execution of the tool clamping steps S1 to S2 of the present invention; Figure 8 This is a schematic diagram of the state during the execution of the pressure relief and reset steps S4 to S6 of the present invention; Figure 9 This is a schematic diagram showing the state during the execution of the rotational separation steps S7 to S8 of the present invention.

[0020] In the diagram: 1; Power head; 2; Turret; 3; Piston; 4; Ring component; 41; Protrusion; 5; Outer ring stepped component; 6; Inner ring stepped component; 7; Disc component; 8; Movable rod; 9; Elastic element; 10; Connecting column; 11; Cutting head; 12; Spindle; 13; Seal; 31; First hydraulic gap; 32; Second hydraulic gap; 41; Protrusion; 51; Groove; 61; Protrusion; 121; Track groove; Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] See Figure 1-9As shown, the present invention provides a technical solution: a hydraulic quick clamping and tool changing device in the middle of a power head, comprising a power head 1 and a tool turret 2. The power head 1 is fixedly connected to the tool turret 2. The power head 1 includes a tool head 11 and a spindle 12 connected inside the tool head 11. A piston 3, a ring 4, an outer ring stepped component 5, an inner ring stepped component 6, and a disc 7 are sequentially sleeved on the outside of the spindle 12. The piston 3 is sleeved on the outside of the spindle 12, with one end near the tool turret 2 opposite to the ring 4 to form a first hydraulic gap 31, and the other end forming a second hydraulic gap 32. The ring 4 is sleeved on the outside of the piston 3 and abuts against the piston 3 and the tool turret 2. The inner ring stepped component 6 and the disc 7 are together... The inner ring stepped component 6 is fixedly connected to the rear end of the piston 3 and sleeved on the outside of the main shaft 12. The outer ring stepped component 5 is sleeved on the outside of the inner ring stepped component 6 and fixedly connected to the disc component 7. The main shaft 12 is provided with a movable rod 8, an elastic element 9 (such as a return spring) and a connecting column 10. The elastic element 9 is sleeved on the outside of the movable rod 8, with its top end abutting against the limiting structure inside the main shaft 12 and its bottom end abutting against the boss on the movable rod 8, so that the bottom end of the movable rod 8 abuts against the inner bottom surface of the main shaft 12 in its natural state. The connecting column 10 passes through the disc component 7 and the movable rod 8 in sequence, and passes through the avoidance structure provided on the main shaft 12 for its axial movement, so that the disc component 7 and the movable rod 8 can move synchronously and connect. By sequentially and coaxially mounting the piston 3, ring 4, outer ring stepped component 5, inner ring stepped component 6, and disc 7 onto the outside of the spindle 12, and linking them with the internal movable rod 8, elastic element 9, and connecting column 10, a highly integrated hydraulic-mechanical drive chain is constructed within the spindle 12's shaft system. This integrated structure significantly shortens the power transmission path, achieving efficient conversion from hydraulic pressure to tool holder thrust during assembly, and significantly improving tool change speed and responsiveness. Simultaneously, the pre-compressed elastic element 9 provides the entire drive chain with automatic and precise mechanical reset capability, eliminating the need for additional reset oil circuits and energy consumption.

[0023] Both piston 3 and annular component 4 have sealing grooves on their outer side walls, and sealing elements are installed in the sealing grooves. This physical structure ensures a reliable seal between the first hydraulic gap 31 and the second hydraulic gap 32. This structure guarantees the airtightness of the hydraulic drive chamber, making the establishment and release of hydraulic force more rapid, stable, and efficient, fundamentally improving the system's operational reliability and energy efficiency.

[0024] A protrusion 41 is provided on the end face of the annular component 4 opposite to the piston 3. This protrusion 41 provides a rigid, insurmountable mechanical stop for the rearward movement of the piston 3. This protrusion 41 structure determines the extreme position of the rearward movement of the piston 3 and the connected inner ring stepped component 6, providing a crucial stroke reference and structural guarantee for the subsequent precise disengagement of the flange 61 from the groove 51.

[0025] The inner ring step 6 is provided with a flange 61, and the outer ring step 5 is provided with a corresponding groove 51. The flange 61 and the groove 51 are engaged. In the initial state and during the working stroke, at least one working surface of the flange 61 is in contact with the corresponding sidewall of the groove 51 to transmit axial force. When the piston 3 moves backward to abut against the protrusion 41, the inner ring step 6 is driven by the piston 3 to generate an axial displacement relative to the outer ring step 5, so that the flange 61 and the groove 51 are disengaged from each other axially, and an axial gap is formed between the inner ring step 6 and the disc 7. By providing a flange 61 on the inner ring step 6 and a corresponding groove 51 on the outer ring step 5, and defining its two states of "contact transmission of axial force" and "disengagement from contact and formation of gap", the clutch function is embedded in the transmission component. Under the limitation of the protrusion 41, the excessive backward movement of the piston 3 can drive the flange 61 to disengage from the groove 51 axially, and form a physical gap between the inner ring step 6 and the disc 7. It enables the transmission and separation of power between rotating and non-rotating drive components, and ensures that the two are completely out of contact after separation to avoid rotational friction.

[0026] The groove 51 on the outer ring step 5 is larger than the flange 61 on the inner ring step 6. This design, where the groove 51 is larger than the flange 61, provides the necessary clearance in both the radial and circumferential directions.

[0027] The connecting column 10, movable rod 8, and disc component 7 are all fixedly connected. This fixed connection ensures instantaneous response. Once the hydraulic oil pushes the piston 3, the force is transmitted through the piston → inner / outer ring step component → disc component to the connecting column 10. Due to the fixed connection, the force is instantly applied to the movable rod, initiating the tool holder movement. There is no waiting time due to backlash, resulting in faster tool changing.

[0028] The clearance structure on the side wall of the main shaft 12 for the axial movement of the connecting column 10 is an axially extending track groove 121. This track groove 121 provides the connecting column 10 with a precise and unique axial movement track, while restricting its radial movement.

[0029] See Figure 3 , Figures 7-9 As shown, based on the aforementioned hydraulic quick-clamping and tool-changing device in the middle of the power head, this embodiment provides a method for hydraulic quick-clamping and tool-changing in the middle of the power head, including the following steps: S1. Hydraulic oil is injected into the first hydraulic gap 31, and the hydraulic oil pushes the piston 3 to move forward along the main shaft 12. S2, the piston 3 drives the inner ring step 6, which is fixedly connected to it, to move forward together. The inner ring step 6, through the contact and cooperation between its flange 61 and the groove 51 on the outer ring step 5, pulls the outer ring step 5 to move forward. The outer ring step 5 drives the disc 7, which is fixedly connected to it, to move forward. S3, the disc component 7 pulls the movable rod 8 forward through the connecting column 10 and compresses the elastic element 9, and the tool holder connected to the front end of the movable rod 8 moves forward synchronously until it is connected to the tool assembly port and completes the docking. S4. After the docking assembly is completed, the device is depressurized, the preload of the elastic element 9 is released, and the movable rod 8 is pushed to move backward. S5, the movable rod 8 drives the disc component 7 and the outer ring step component 5 to move backward together through the connecting column 10; S6. The outer ring step 5, through the contact engagement between the groove 51 and the flange 61, pulls the inner ring step 6 and the piston 3 to move backward and reset together, thereby locking the tool after tool change. S7. Inject hydraulic oil into the second hydraulic gap 32 to push the piston 3 to continue moving backward along the main shaft 12; S8. The piston 3 drives the inner ring step 6 to move backward synchronously until the piston 3 abuts against the protrusion 41 on the ring 4. S9. Under the limiting action of the protrusion 41, the flange 61 on the inner ring step 6 and the groove 51 on the outer ring step 5 change from abutting to disengaging, and a gap is formed between the inner ring step 6 and the disc 7, so that the outer ring step 5 and the disc 7 can rotate together with the main shaft 12 without interference.

[0030] This invention discloses a hydraulic rapid clamping and tool changing method for the power head. The core drive components, including piston 3, ring 4, outer ring stepped component 5, inner ring stepped component 6, and disc 7, are sequentially and coaxially sleeved around the outside of the spindle 12. These components are linked to the internal movable rod 8 via connecting column 10, creating a highly integrated hydraulic-mechanical drive chain. This significantly shortens the power transmission path and ensures rapid response during clamping and tool changing. Utilizing the energy stored in the pre-compressed elastic element 9, the entire drive chain can be automatically and accurately reset to its initial position after hydraulic depressurization, eliminating the need for an additional power source and control. This simplifies the system and ensures repeatability. Through the mating structure of flange 61 and groove 51, and the limiting effect of protrusion 41, reliable engagement of the drive components and rotating components during operation and complete physical separation during high-speed rotation are achieved, forming an axial clearance. This avoids frictional interference and improves spindle accuracy and lifespan.

Claims

1. A hydraulic quick-clamping and tool-changing device for a power head, comprising a power head (1) and a tool turret (2), wherein the power head (1) is fixedly connected to the tool turret (2), and the power head (1) includes a tool head (11) and a spindle (12) connected to the inside of the tool head (11), characterized in that, The main shaft (12) is sequentially fitted with a piston (3), a circular ring (4), an outer ring stepped part (5), an inner ring stepped part (6), and a disc (7); the piston (3) is fitted outside the main shaft (12), with one end near the turret (2) opposite to the circular ring (4) and forming a first hydraulic gap (31), and the other end forming a second hydraulic gap (32); the circular ring (4) is fitted outside the piston (3) and abuts against the piston (3) and the turret (2); the inner ring stepped part (6) and the disc (7) are fitted together outside the main shaft (12), the inner ring stepped part (6) is fixedly connected to the rear end of the piston (3), and the outer ring stepped part (5) is fixedly connected to the rear end of the piston (3). 5) It is sleeved on the outside of the inner ring step (6) and fixedly connected to the disc (7); the main shaft (12) is provided with a movable rod (8), an elastic element (9) and a connecting column (10). The elastic element (9) is sleeved on the outside of the movable rod (8), its top end abuts against the limiting structure inside the main shaft (12), and its bottom end abuts against the boss on the movable rod (8), so that the bottom end of the movable rod (8) abuts against the inner bottom surface of the main shaft (12) in a natural state; the connecting column (10) passes through the disc (7) and the movable rod (8) in sequence, and passes through the avoidance structure provided on the main shaft (12) for its axial movement, so that the disc (7) and the movable rod (8) can be connected synchronously.

2. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 1, characterized in that, Both the piston (3) and the annular component (4) have sealing grooves on their outer side walls, and a sealing component (13) is provided in the sealing groove.

3. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 1, characterized in that, The annular component (4) has a protrusion (41) on one end face opposite to the piston (3).

4. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 3, characterized in that, The inner ring step (6) is provided with a flange (61), and the outer ring step (5) is provided with a corresponding groove (51). The flange (61) and the groove (51) cooperate. During the working stroke, at least one working surface of the flange (61) contacts the corresponding side wall of the groove (51) to transmit axial force. When the piston (3) moves backward to abut against the protrusion (41), the inner ring step (6) is driven by the piston (3) to generate an axial displacement relative to the outer ring step (5), so that the flange (61) and the groove (51) disengage from each other in the axial direction, and an axial gap is formed between the inner ring step (6) and the disc (7).

5. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 4, characterized in that, The groove (51) on the outer ring step (5) is larger than the flange (61) on the inner ring step (6).

6. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 1, characterized in that, The connecting column (10) is fixedly connected to the movable rod (8) and the disc component (7).

7. The hydraulic quick-clamping and tool-changing device in the middle of the power head according to claim 1, characterized in that, The clearance structure provided on the side wall of the main shaft (12) for the axial movement of the connecting column (10) is an axially extending track groove (121).

8. A rapid tool clamping and changing method based on the device according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Hydraulic oil is injected into the first hydraulic gap (31), and the hydraulic oil pushes the piston (3) to move forward along the main shaft (12); S2. The piston (3) drives the inner ring step (6) which is fixedly connected to it to move forward together. The inner ring step (6) pulls the outer ring step (5) forward by contacting the flange (61) on it with the groove (51) on the outer ring step (5). The outer ring step (5) drives the disc (7) which is fixedly connected to it to move forward. S3, the disc component (7) pulls the movable rod (8) forward through the connecting column (10) and compresses the elastic element (9), and the tool holder connected to the front end of the movable rod (8) moves forward synchronously until it is connected to the tool assembly port and completes the docking.

9. The rapid tool clamping and changing method according to claim 8, characterized in that, It also includes a pressure relief and reset step: S4. When the assembly is completed, the device is depressurized, the preload of the elastic element (9) is released, and the movable rod (8) is pushed to move backward. S5. The movable rod (8) drives the disc component (7) and the outer ring step component (5) to move backward together through the connecting column (10); S6. The outer ring step (5) pulls the inner ring step (6) and piston (3) backward together to reset through the contact and cooperation of the groove (51) and the flange (61), thereby locking the tool after tool change.

10. The rapid tool changing method according to claim 9, characterized in that, It also includes a rotational separation step: S7. Inject hydraulic oil into the second hydraulic gap (32) to push the piston (3) to continue moving backward along the main shaft (12); S8. The piston (3) drives the inner ring step (6) to move backward synchronously until the piston (3) abuts against the protrusion (41) on the ring (4). S9. Under the limiting action of the protrusion (41), the flange (61) on the inner ring step (6) and the groove (51) on the outer ring step (5) change from contact to discontinuation, and a gap is formed between the inner ring step (6) and the disc (7), so that the outer ring step (5) and the disc (7) can rotate together with the main shaft (12) without interference.

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