A dynamic accuracy compensation device for the bottom dead center of a high-speed precision punch press

Abstract

The application discloses a high-speed precise punch lower dead point dynamic precision compensation device, which comprises a fixed block, a worm gear mechanism and a screw nut block mechanism; the worm gear mechanism is used as a power input component of the compensation device and drives the rotation of the screw nut block mechanism; the nut block of the screw nut block mechanism is fixedly connected with the fixed block, the screw shaft is matched with the worm wheel of the worm gear mechanism and can move axially relative to the worm wheel; the lower end of the screw shaft is provided with a ball head which is used for contacting with the spherical surface of a moving block; the moving block can vertically move under the guidance of a machine tool, so as to finely adjust the machine tool slide block up and down and further adjust the lower dead point precision of the punch; and the fixed block is provided with a backlash compensation mechanism which is used for eliminating the backlash of the screw nut block mechanism. The high-speed precise punch lower dead point dynamic precision compensation device adopts the precise guide adjustment mode of the screw nut and eliminates the movement gap through a thread gap elimination system, so that the transmission parts are closely matched, and the lower dead point dynamic precision of the punch can be efficiently compensated.

Description

Technical Field

[0001] This invention belongs to the field of high-speed precision punching presses, and in particular relates to a dynamic accuracy compensation device for the bottom dead center of a high-speed precision punching press. Background Technology

[0002] The dynamic accuracy of the bottom dead center (BDC) of a high-speed precision punch press is its most important performance indicator. It directly reflects the manufacturing level and machining precision of the press, and limits its application areas and the lifespan of the dies. As the number of strokes of the slide in a high-speed punch press gradually increases, the acceleration of the press's motion mechanism increases, leading to an increase in the inertial force of the components and causing the bottom dead center to drift. During high-speed operation, heat sources such as frictional heating of moving parts, heat generated by motor power consumption, heat generated during part processing, and ambient temperature all contribute to an uneven temperature field on the press, causing thermal deformation of parts and ultimately resulting in a change in the BDC position. To achieve high BDC accuracy, setting up a dynamic accuracy compensation device is an effective method. This device fine-tunes the position of the BDC, maintaining high stamping precision.

[0003] Patent CN212499089U discloses a dynamic compensation mechanism for the bottom dead center accuracy of a high-speed punch press. This mechanism uses a servo motor to drive a coupling, causing a ball screw to rotate. This, in turn, moves a slider forward or backward, adjusting the position of the two connecting rods on the punch press to compensate for the bottom dead center accuracy. However, because this compensation mechanism uses a ball screw drive, which is a point-contact kinematic pair, stress concentration can occur under the impact load of the punch press, reducing the service life of the compensation device. Furthermore, gaps exist between the parts adjusting the accuracy, causing fluctuations in the bottom dead center of the punch press during high-speed operation, thus failing to achieve the intended compensation effect. Patent CN207695413U discloses a punch press slider accuracy compensation mechanism that considers the gaps in the punch press transmission mechanism. It uses a lifting device to lift the slider upwards to eliminate the gaps between parts, improving the punching accuracy of the slider. The lifting device acts directly on the slide block and moves synchronously with it. This adds an extra load to the press, and because hydraulic oil is compressible, it can cause instability in the press's operation under variable load conditions, increasing the difficulty of controlling the bottom dead center accuracy. Patent CN110842073A discloses a bottom dead center compensation structure for a toggle-type press that directly controls the adjusting rod via a servo motor, thereby adjusting the balance rod to compensate for the bottom dead center accuracy. This toggle-type press has a symmetrical structure on both sides, requiring two servo motors to control the adjusting rods on both sides. The adjusting mechanisms on both sides need to maintain a high degree of synchronization, increasing the complexity and instability of accuracy compensation and requiring highly sophisticated synchronization control technology. Summary of the Invention

[0004] The purpose of this invention is to provide a dynamic accuracy compensation device for the bottom dead center of a high-speed precision punch press, so as to adjust the dynamic accuracy of the bottom dead center of the high-speed precision punch press.

[0005] The technical solution to achieve the purpose of this invention is as follows:

[0006] A dynamic accuracy compensation device for the bottom dead center of a high-speed precision punch press includes:

[0007] A fixing block is used to connect the worm gear mechanism and the lead screw nut block mechanism.

[0008] The worm gear mechanism, as the power input component of the compensation device, is used to drive the rotation of the lead screw and nut block mechanism;

[0009] The nut block of the lead screw nut block mechanism is fixedly connected to the fixed block, and the lead screw shaft is engaged with the worm wheel of the worm gear mechanism, allowing it to move axially relative to the worm wheel; the lower end of the lead screw shaft is provided with a ball head for contacting the spherical surface of the moving block;

[0010] The movable block is used to move vertically under the guidance of the machine tool to finely adjust the upper and lower slide of the bottom machine tool, thereby adjusting the accuracy of the bottom dead center of the punch.

[0011] The fixed block is equipped with a backlash compensation mechanism, which is used to eliminate backlash in the lead screw and nut block mechanism.

[0012] The significant advantages of this invention compared to existing technologies are:

[0013] The screw shaft is lifted axially by a thread backlash elimination system, maintaining tight contact between the screw shaft and the nut block threaded connection. This prevents internal component wobbling due to impact loads from the punch press and improves compensation accuracy by eliminating backlash, ensuring real-time transmission of compensation adjustments to the punch press mechanism. The threaded drive itself has self-locking characteristics, maintaining device stability and providing precise transmission under impact loads. The ball joint drive effectively resists impact loads. Eight guide shims guide the moving block, with one block connecting to the rotating shafts on both sides of the punch press. This allows simultaneous adjustment of the rotating pairs on both sides of the punch press mechanism, maintaining high symmetry and synchronization. The eight-sided guide mechanism maintains high vertical straightness of the moving block, and the position of the moving block can be adjusted by adjusting the guide shims. Therefore, this precision compensation device efficiently compensates for the dynamic accuracy of the punch press mechanism's bottom dead center. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the structure of the present invention.

[0015] Figure 2 This is a simplified diagram of a multi-link high-speed precision punch press used in this invention.

[0016] Figure 3 This is a cross-sectional view of the slider eight-sided guide mechanism of the present invention. Detailed Implementation

[0017] It should be noted that in the description of this invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Combination Figure 1 and Figure 2 The present invention is placed above the rotating joint 22 of the punch press. The position of the rotating joint 22 on both sides of the punch press is adjusted up and down by moving the moving block 7, which in turn drives the connecting rod 19 to drive the slider 23 to make fine adjustments up and down, so as to achieve the effect of compensating for the dynamic accuracy of the bottom dead point.

[0019] like Figure 1As shown, a dynamic accuracy compensation device for the bottom dead center of a high-speed precision punch press includes a worm gear mechanism, a lead screw and nut block mechanism, a slide guide mechanism, a thread backlash elimination system, and a ball head lubrication system. The worm gear mechanism includes a worm 1, a worm wheel 2, and a fixed block 3. The fixed block 3 has a circular through hole in its center and is fixed to the upper part of the machine body. The worm 1 is horizontally positioned on the right side of the fixed block 3 and its rotation is controlled by a servo motor. The worm 1 and worm wheel 2 are cross-connected, with the worm wheel 2 placed horizontally at the center of the fixed block 3. The worm wheel 2 has a spline hole 2a inside. The lead screw and nut block mechanism includes a lead screw shaft 4 and a nut block 5. The lead screw shaft 4 has a thread 4c in the middle, a spline groove 4a at one end, and a ball head 4d at the other end. The nut block 5 is fixed to the circular hole below the fixed block 3 by screws 6. The lead screw shaft 4 and the nut block 5 form a threaded drive, and the worm wheel 2 passes through an internal... The spline hole 2a is connected to the spline groove 4a of the lead screw shaft 4; the slider guide mechanism includes a moving block 7, a guide block 17, and guide pads 18. The moving block 7 has a recessed spherical hole 7a at the center of its upper part and circular holes 7b that pass through it on both sides of its lower part. Eight guide pads 18 are connected to four guide blocks 17. The four guide blocks 17 are fixed to the machine body 21 at the four corners inside the machine body 21. The moving block 7 contacts the eight guide pads 18 respectively, forming an eight-sided conduction. The moving block 7 can move vertically in the machine body 21; the thread gap elimination system includes a connecting shaft 10, a connecting screw 11, a sealing block 12, and a sealing ring 13. 14 and high-pressure oil chamber A, the connecting shaft 10 has a threaded hole in its center, and the lead screw shaft 4 has a threaded hole in its center above. The connecting screw 11 passes through the threaded hole of the connecting shaft 10 to fix the connecting shaft 10 to the lead screw shaft 4. The connecting screw 11, the lead screw shaft 4 and the connecting shaft 10 are coaxial. The sealing block 12 is sleeved on the outside of the connecting shaft 10 and fixed to the fixing block 3 by the screw 13. The sealing block 12 has an oil inlet 12a on its right side. The upper end of the connecting shaft 10 has a boss structure, which forms a piston-cylinder-like structure with the sealing block 12. A groove is formed below the boss of the connecting shaft 10. A high-pressure oil chamber A has two sealing rings (13 / 14) installed above and below the groove of the connecting shaft 10. The ball head lubrication system includes a top cover 15 and a low-pressure oil chamber B. The top cover 15 is covered above the sealing block 12 by screws 16. An L-shaped oil inlet hole 15a is opened on the right side of the top cover 15. The top cover 15, the sealing block 12 and the connecting shaft 10 form a low-pressure oil chamber B inside. A circular through hole (11a / 4b) is opened in the center of the connecting screw 11 and the lead screw shaft 4, which can connect the low-pressure oil chamber B and the ball head 4d at their relative rotational positions.

[0020] like Figure 1As shown, the ball head 4d of the lead screw shaft 4 is connected to the moving block 7 and the ball head cover 8. Both the moving block 7 and the ball head cover 8 have recessed spherical holes (7a / 8a) inside. The ball head cover 8 is fixed to the moving block 7 by screws 9. The moving block 7 is connected below the ball head 4d, and the ball head cover 8 is connected above the ball head 4d. The moving block 7 and the ball head cover 8 form an oil cavity C on both sides of the ball head 4d, ensuring that the lubricating oil can fully lubricate the ball head 4d. When the lead screw shaft 4 rotates and moves vertically, the moving block 7 can be driven to move vertically through the ball head 4d. The ball head 4d maintains surface contact with the spherical holes (7a / 8a) inside the moving block 7 and the ball head cover 8, which can better withstand impact loads and maintain transmission stability.

[0021] like Figure 1 As shown, a short journal is machined above the lead screw shaft 4, and a shallow hole is opened below the connecting shaft 10. The journal and the shallow hole fit together perfectly to maintain coaxiality during connection.

[0022] like Figure 1 As shown, a spline groove 4a is opened in the middle of the lead screw shaft 4, and a spline hole 2a is opened inside the worm gear 2. The worm gear 2 is connected to the lead screw shaft 4 through the spline. When the worm gear 2 drives the lead screw shaft 4 to rotate, the lead screw shaft 4 can move vertically relative to the worm gear 2. The worm gear 2 cannot move vertically due to the groove formed by the lower part of the sealing cover 12 and the fixing block 3.

[0023] like Figure 1 As shown, the sealing block 12 has a cylindrical boss at its lower end, and the fixing block 3 has a boss at its upper end. The sealing block 12 is fixed to the fixing block 3 by screws 13, and the sealing block 12 and the connecting shaft 4 are kept coaxial.

[0024] like Figure 1 Figure 3 As shown, the hole 7b of the movable block 7 is fixedly connected to the punch press rotating shaft 20, and the rotating shaft 20 and the connecting rod 19 are connected by a sliding bearing.

[0025] like Figure 1 As shown, the diameter of the threaded portion 4c of the lead screw shaft 4 is larger than the diameter above the thread, which makes it convenient for the lead screw shaft 4 to pass through the underside of the nut block 5 and then rotate onto the nut block 5 through the thread.

[0026] Combination Figure 1-3As shown, before the compensation device starts working, high-pressure oil is first introduced into the high-pressure oil chamber through the oil inlet 12a on the right side of the sealing block 12. Due to its own pressure, the high-pressure oil expands outward, exerting an upward lifting force on the connecting shaft 10. The connecting shaft 10 and the lead screw shaft 4 are fixedly connected by the connecting screw 11. The connecting shaft 10 drives the lead screw shaft 4 to lift upward, causing the threads of the lead screw shaft 4 and the nut block 5 to abut against each other, eliminating the gap. During operation, the servo motor drives the worm gear 1 to rotate, the worm gear 1 drives the worm wheel 2 to rotate, and the worm wheel 2 drives the lead screw shaft 4 to rotate through the spline connection. The lead screw shaft 4 and the nut block 5 are connected by threads. Since the nut block 5 is fixed, the rotation of the lead screw shaft 4 is converted into vertical movement. The lower end ball head 4d of the lead screw shaft 4 rotates relative to the moving block 7 and the ball head cover 8, which drives the moving block 7 to move vertically. The moving block 7 and the guide washer 18 form an adjustable eight-sided guide, which enables the moving block 7 to maintain a high degree of verticality during vertical movement. The movement of the moving block 7 will adjust the position of the punch press rotary joint 22, thereby adjusting the accuracy of the punch press bottom dead center. In addition, oil passage holes (11a / 4b) are opened inside the connecting screw 11 and the lead screw shaft 4. Lubricating oil enters the upper low-pressure oil chamber B through the oil inlet 15a on the right side of the top cover 15. Due to the pressure of the lubricating oil itself and gravity, it is transmitted to the friction point of the ball head 4d at the lower end of the lead screw shaft 4 through the oil passage channels 11a and 4b, providing lubrication for the movement of the ball head 4d contact connection part.

Claims

1. A high speed precision punch lower dead center dynamic accuracy compensation device, characterized in that, The utility model relates to a machine tool's slide block verticality adjusting device, including: Fixed block, worm gear mechanism, screw nut block mechanism, moving block and anti-backlash compensation mechanism and lubricating system; The fixed block is connected with the machine body and is used for connecting the worm gear mechanism and the screw nut block mechanism; The worm gear mechanism is used as the power input part of the compensation device and drives the rotation of the screw nut block mechanism; The screw nut block mechanism includes a screw shaft and a nut block; the screw shaft is threaded in the middle, has a spline groove at the upper end, and is provided with a ball head at the lower end; a spline hole is formed in the worm gear; the worm gear is connected with the screw shaft through the spline and the screw shaft; The nut block is fixedly connected with the fixed block, the screw shaft is matched with the worm gear, and the screw shaft can move axially relative to the worm gear; the ball head at the lower end of the screw shaft is used for spherical contact with the moving block; The moving block can vertically move under the guidance of the machine tool to finely adjust the machine tool slide block and then adjust the lower dead point precision of the punch press; The fixed block is provided with an anti-backlash compensation mechanism, which is used for anti-backlash of the screw nut block mechanism; the anti-backlash compensation mechanism adopts a piston cylinder mechanism, the piston cylinder mechanism is coaxially connected with the screw shaft, and an axial force is applied to the screw shaft; the piston cylinder mechanism is provided with a high-pressure oil cavity and a low-pressure oil cavity, which are used as a lubricating system; the high-pressure oil cavity is used as an oil cavity for anti-backlash of the screw nut block mechanism, and the low-pressure oil cavity is used as an oil supply oil cavity for lubrication of the ball head and the moving block.

2. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 1, wherein, A sealing block is fixedly arranged at the upper end of the fixed block and is used as a cylinder body of the piston cylinder mechanism; a connecting shaft is arranged in the sealing block and is used as a piston of the piston cylinder mechanism; the connecting shaft is coaxially connected with the screw shaft.

3. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 2, wherein, The connecting shaft is connected with the screw shaft through a connecting screw.

4. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 2, wherein, A shaft neck is arranged above the screw shaft, a hole is arranged below the connecting shaft, the shaft neck and the hole are clamped together, and the coaxiality of the screw shaft and the connecting shaft is maintained.

5. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 3, wherein, Round through holes are formed in the center of the connecting screw and the screw shaft, which are used for communication between the low-pressure oil cavity and the ball head in the relative rotating position.

6. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 1, wherein, A ball head cover is fixedly arranged on the moving block; concave spherical holes are formed in the moving block and the ball head cover; the ball head is in surface contact with the spherical holes in the moving block and the ball head cover; the moving block and the ball head cover form two oil cavities on both sides of the ball head.

7. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 1, wherein, A spline groove is formed on the outer part of the screw shaft, a spline hole is formed in the worm gear, and the worm gear is connected with the screw shaft through the spline.

8. The high speed precision punch bottom dead center dynamic accuracy compensation device of claim 1, wherein, The moving block is in contact with eight guide pads, eight-side conduction is formed, the eight guide pads are connected with four guide blocks, the four guide blocks are fixedly connected with the machine body at four corners of the machine body; two circular holes are formed in the lower part of the moving block and penetrate the moving block, which are used for connecting the connecting rod of the machine tool slide block through a rotating shaft.

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