Double-drive Z-axis ram structure

Abstract

The invention relates to the field of gantry machining centers, and particularly discloses a double-drive Z-axis ram structure which comprises a ram body connected to a sliding saddle in a sliding mode, a linear roller guide rail is arranged between the ram body and the sliding saddle along the diagonal line, and the ram body is provided with a Z-axis driving assembly and a Z-axis driving assembly, the lead screw is provided with a lead screw nut fixedly connected to the sliding saddle. And the force equalizing mechanism comprises hydraulic cylinders which are in different planes with the lead screws and are symmetrically arranged along the central axis of the pillow body. When the pillow body needs to be driven to move along the Z axis, the output end of the hydraulic cylinder keeps pressure and the dead weight of the pillow body for hedging, so that the load of the dead weight of the pillow body on the lead screw, the lead screw nut, the linear roller guide rail and the sliding block is reduced, the stability of the combination surface is kept, and the service life of the pillow body is prolonged during high-speed cutting or impact cutting. Damping is carried out through pressure output by the hydraulic cylinder, and the dynamic response of the pillow body is optimized.

Description

Technical Field

[0001] This invention relates to gantry machining center technology, specifically a dual-drive Z-axis slide structure. Background Technology

[0002] As is well known, the box-in-box sliding ram structure has good rigidity and thermal stability, and is a commonly used improvement solution in high-end gantry machining centers. It has high precision and is suitable for machining scenarios that require high precision, such as aerospace equipment.

[0003] For example, the invention patent with publication number CN102049705B, publication date March 13, 2013, entitled "A High-Speed ​​Gantry Five-Axis Machining Center with Interchangeable Milling Heads and Direct Drive," features two linear guide rails on the left and right bridges respectively. The slide plate slides along the guide rails on the crossbeam via a slider. The ram and slide plate are connected by a double lead screw drive. An AC double swing head is installed at the bottom of the ram, and the head magazine is placed on one side of the worktable. The two ends of the crossbeam are mounted on the left and right bridges respectively via sliding blocks. The X and Y axes of the five-axis machining center are directly driven by linear motors. The crossbeam moves horizontally along the left and right bridges in the X direction, and the slide plate moves horizontally along the crossbeam in the Y direction. The Z-axis of the five-axis machining center is driven by the center of gravity of the dual motors, and the ram moves vertically in the Z direction on the slide plate. This invention operates smoothly and has stable performance, making it suitable for precision machining of molds in aerospace, aviation, and automotive industries.

[0004] The shortcomings of the existing technology are that the box-in-box slide structure has two layers: slide and saddle. The spindle and its components are mounted on the slide and move in the Z-axis direction as the slide moves, which makes the entire slide heavy and puts a heavy burden on the drive slide. In addition, the joint surface (such as guide rail and slider) between the two layers of slide and saddle is fragile. The combination of the two results in insufficient system damping during high-speed cutting or impact cutting, which leads to poor dynamic response and affects machining accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-drive Z-axis slide structure to overcome the above-mentioned shortcomings in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dual-drive Z-axis ram structure, comprising a ram body slidably connected to a saddle, wherein a linear roller guide rail is provided diagonally between the ram body and the saddle, and the ram body is respectively provided with:

[0007] The Z-axis drive assembly includes a lead screw symmetrically arranged along the central axis of the pillow body, and a lead screw nut fixedly connected to the slide saddle on the lead screw;

[0008] The force equalization mechanism includes a hydraulic cylinder that is opposite to the lead screw and symmetrically arranged along the central axis of the pillow body, and a top plate corresponding to the hydraulic cylinder is symmetrically arranged on the pillow body.

[0009] As a further description of the above technical solution: a support ball is provided on the top plate, a top sleeve is provided on the output end of the hydraulic cylinder, and a hemispherical sleeve corresponding to the support ball is provided on the top sleeve.

[0010] As a further description of the above technical solution: a rotating sleeve is rotatably connected to the hemispherical sleeve, the rotating sleeve supports the supporting ball, the rotating sleeve extends with the pillow body, and flips along the plane parallel to the central axis.

[0011] As a further description of the above technical solution: a limiting rail is provided on the sliding saddle, a flip bar is provided on the rotating sleeve and slidably connected to the limiting rail, and an inclined portion is provided on the limiting rail.

[0012] As a further description of the above technical solution: a horizontal plate is provided on the top sleeve, and a pad is slidably connected to the horizontal plate. The pad is driven to slide between the top plate and the horizontal plate.

[0013] As a further description of the above technical solution: the hydraulic cylinder is provided with a guide frame, and the top plate is slidably connected to the guide frame.

[0014] As a further description of the above technical solution: a pad is slidably connected in the top sleeve of the hydraulic cylinder, and a limiting protrusion is provided on the guide frame. The pad moves with the pillow body, so that the limiting protrusion squeezes the pad to move.

[0015] As a further description of the above technical solution: the top plate is provided with an oblique angle, and the pad slides away from the support ball along the oblique angle according to the weight of the pillow body.

[0016] As a further description of the above technical solution: the linear roller guide is arranged on the same plane as the lead screw.

[0017] As a further description of the above technical solution: a sealing plate is provided at the upper end of the guide frame, and the top sleeve extends past the sealing plate along with the hydraulic cylinder to adapt for hoisting.

[0018] In the above technical solution, the dual-drive Z-axis slide ram structure provided by the present invention has the following beneficial effects: when it is necessary to drive the ram body to move along the Z-axis, the hydraulic cylinder output end maintains pressure and the ram body's own weight to counteract each other, thereby reducing the load of the ram body's own weight on the lead screw and lead screw nut, linear roller guide and slider, maintaining the stability of the mating surface, and in high-speed cutting or impact cutting, the pressure output by the hydraulic cylinder is used for damping, optimizing the dynamic response of the ram body. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram of the pillow structure provided in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the pillow body and force equalization structure provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic cross-sectional view of the pillow structure provided in an embodiment of the present invention;

[0023] Figure 4 This is an exploded view of the force equalization mechanism provided in an embodiment of the present invention;

[0024] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0025] Figure 6 This is a schematic diagram of the top plate structure provided in an embodiment of the present invention;

[0026] Figure 7 This is a schematic cross-sectional view of the pillow structure provided in an embodiment of the present invention;

[0027] Figure 8 for Figure 7 Enlarged view of point B in the middle;

[0028] Figure 9 for Figure 7 Enlarged view of point C in the middle;

[0029] Figure 10 for Figure 7 Another enlarged schematic diagram of the embodiment at point C;

[0030] Figure 11 This is a schematic diagram of the guide frame and limiting protrusion structure provided in an embodiment of the present invention;

[0031] Figure 12 for Figure 11 Enlarged view of point D;

[0032] Figure 13 for Figure 11 Another enlarged schematic diagram of an embodiment at point D;

[0033] Figure 14 This is a schematic diagram of the inclined support of the hemispherical sleeve provided in an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Pillow body; 10. Slot; 11. Guide rail; 111. Slider; 12. Through slot; 2. Z-axis drive assembly; 20. Motor; 21. First bearing seat; 22. Second bearing seat; 23. Lead screw; 24. Lead screw nut; 3. Force equalizing mechanism; 31. Hydraulic cylinder; 32. Rotating sleeve; 321. Rotating protrusion; 322. Flip rod; 323. Limiting rail; 3231. Inclined section; 33. Top plate; 330. Piezoelectric ceramic plate; 331. Support ball; 332. Slide groove; 333. Through channel; 334. Angled angle; 34. Top sleeve; 341. Hemispherical sleeve; 342. Horizontal plate; 35. Pad plate; 36. Guide frame; 361. Central limiting rod; 362. Limiting protrusion. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0037] Please see Figure 1-14 This invention provides a technical solution: a dual-drive Z-axis ram structure, including a ram body 1 slidably connected to a saddle, a linear roller guide 11 diagonally arranged between the ram body 1 and the saddle, the linear roller guide 11 being fixedly connected to the side of the ram body 1 by screws, the linear roller guide 11 and a lead screw 23 being arranged on the same plane, a slider 111 slidably connected to the linear roller guide 11, the slider 111 being fixedly connected to the saddle by screws, the ram body 1 sliding along the saddle in the Z-axis direction, and a Z-axis drive assembly 2 and a force equalizing mechanism 3 respectively arranged on the ram body 1. The Z-axis drive assembly 2 includes lead screws 23 symmetrically arranged along the central axis of the ram body 1, such as... Figure 2As shown, a first bearing seat 21 and a second bearing seat 22 are respectively provided at both ends of the pillow body 1. Bearings are provided inside the first bearing seat 21 and the second bearing seat 22. The two ends of the lead screw 23 are respectively provided on the bearings and rotate along the first bearing seat 21 and the second bearing seat 22. There are two lead screws 23, which are provided on both sides of the pillow body 1 so that the lead screws 23 are symmetrical along the central axis of the pillow body 1. The lead screw nut 24 is threaded on the lead screw 23 and fixed on the slide saddle. Thus, by driving the lead screw 23 to rotate, the pillow body 1 is moved along the slide saddle. A motor 20 is provided at the top of the pillow body 1. The output end of the motor 20 and the lead screw 23 are connected through a coupling. A force equalization mechanism 3 is provided on the pillow body 1. The force equalization mechanism 3 includes a hydraulic cylinder 31 installed on the inner wall of the slide saddle. A top plate 33 is provided on the top of the pillow body 1. The top plate 33 extends out of the pillow body 1 to the side, which is the opposite side of the lead screw 23. The output end of the hydraulic cylinder 31 presses against the top plate 33. The hydraulic cylinder 31 is installed on the slide saddle to support the pillow body 1. When it is necessary to drive the pillow body 1 to move along the Z-axis, the output end of the hydraulic cylinder 31 maintains pressure and counteracts the weight of the pillow body 1, thereby reducing the load of the weight of the pillow body 1 on the lead screw 23 and lead screw nut 24, linear roller guide 11 and slider 111, maintaining the stability of the mating surface. In high-speed cutting or impact cutting, the pressure output by the hydraulic cylinder 31 provides damping and optimizes the dynamic response of the pillow body 1.

[0038] Furthermore, a through groove 12 is provided on the pillow body 1 for heat dissipation.

[0039] When the pillow body 1 is assembled with the slide saddle, it is fixed to the top of the pillow body 1 by ropes, the pillow body 1 is lifted up, the pillow body 1 is aligned with the slide saddle after being lifted up, and the output end of the hydraulic cylinder 31 is driven to extend and press against the top plate 33 to provide guidance.

[0040] In another embodiment provided by the present invention, such as Figure 5 As shown, a support ball 331 facing the output end of the hydraulic cylinder 31 is provided on the top plate 33. A top sleeve 34 is provided on the output end of the hydraulic cylinder 31. A hemispherical sleeve 341 corresponding to the support ball 331 is provided on the top sleeve 34. The bottom size of the hemispherical sleeve 341 is the same as that of the support ball 331. The outer ring size of the hemispherical sleeve 341 is larger than that of the hemispherical sleeve 341. When the pillow body 1 is assembled with the sliding saddle, the hemispherical sleeve 341 is the first part to connect with the support ball 331. At this time, the outer ring of the hemispherical sleeve 341 guides the position of the pillow body 1. As the pillow body 1 is gradually lowered by hoisting, the support ball 331 and the bottom of the hemispherical sleeve 341 are connected, which facilitates the subsequent fixing of the slider 111 and the screw nut 24.

[0041] In another embodiment provided by the present invention, such as Figure 5As shown, the hemispherical sleeve 341 has an arc groove that passes through it. The force equalizing mechanism 3 also includes a rotating sleeve 32. The rotating sleeve 32 has a rotating protrusion 321 corresponding to the arc groove. The rotating protrusion 321 is rotatably connected to the hemispherical sleeve 341. The hemispherical sleeve 341 and the support ball 331 are rotatably connected. After the pillow body 1 is hoisted, the hydraulic cylinder 31 is retracted without driving the lead screw 23. At this time, the rotating sleeve 32 is installed at the output end of the hemispherical sleeve 341 and the hydraulic cylinder 31 for use. When the pillow body 1 is in use, when it extends a distance along the slide saddle along the Z-axis according to the needs of the machine tool, the rotating sleeve 32 will flip along the arc groove (that is, flip along the plane parallel to the central axis), so that the support in the vertical direction of the rotating sleeve 32 moves to the support in the inclined direction. At this time, the vibration in the direction of the two hydraulic cylinders 31 will be relieved by the rotating sleeve 32 in the inclined state after flipping, thereby relieving the vibration caused by the excessive extension of the pillow body 1.

[0042] Preferred, such as Figure 5 and Figure 9 As shown, the inner wall of the sliding saddle is provided with ribs to increase support, and a limiting rail 323 is provided on the ribs. A flip rod 322 is slidably connected to the limiting rail 323 on the rotating sleeve 32. An inclination portion 3231 is provided on the limiting rail 323, which is closer to the pillow body 1. When the pillow body 1 moves along the Z-axis and extends out of the sliding saddle, the flip rod 322 on the rotating sleeve 32 also slides along the limiting rail 323 as the rotating sleeve 32 moves. When the flip rod 322 reaches the inclination portion 3231, the inclination portion 3231 approaches the pillow body 1, causing the rotating sleeve 32 to flip along the hemispherical sleeve 341, thus changing the support direction. Figure 8 The middle horizontal shading is flipped to Figure 14 The tilted support in the middle increases the restriction on the side of the pillow body 1, thus mitigating vibration in that direction.

[0043] In another embodiment provided by the present invention, such as Figure 5 and Figure 8 As shown, a horizontal plate 342 is provided on the top sleeve 34, and a slot 10 is provided on the top of the pillow body 1. The top plate 33 is snapped into the slot 10 and fixed with screws. The top plate 33 and the horizontal plate 342 are arranged in parallel. A groove is provided on the top plate 33 and the horizontal plate 342. A pad 35 is slidably connected to the groove. During use, the hydraulic cylinder 31 will continuously pressurize to reduce the self-weight load of the pillow body 1. At this time, the friction between the support ball 331 and the rotating sleeve 32 increases due to the pressure of the load. This drives the rotating sleeve 32 to rotate. Due to the high wear due to the pressure, the pad 35 is slid along the groove to the space between the top plate 33 and the horizontal plate 342 before rotation to share part of the pressure of the support ball 331 and the rotating sleeve 32, thereby reducing the friction between the support ball 331 and the rotating sleeve 32. While continuously counteracting the load of the pillow body 1, the damage to the support ball 331 and the rotating sleeve 32 is reduced, and the equipment maintenance time is extended.

[0044] In another embodiment of the present invention, a guide frame 36 is provided on the slide saddle, and the fixed part of the hydraulic cylinder 31 is fixedly connected to the guide frame 36. A slide groove 332 and a through channel 333 are symmetrically provided on the top plate 33. The guide frame 36 is slidably connected to the slide groove 332. A central limiting rod 361 is provided at the center of the guide frame 36 and is slidably connected in the through channel 333. The upper end of the guide frame 36 is an open end. A sealing plate is provided at the upper end of the guide frame 36 to restrict the top plate 33. The guide frame 36 plays a guiding role, increases the contact surface between the pillow body 1 and the slide saddle, and reduces vibration. The sealing plate is suitable for hoisting, can be disassembled before hoisting, and can be installed after hoisting.

[0045] Preferably, the central limiting rod 361 is provided with a limiting protrusion 362, and the grooves opened in the top plate 33 and the horizontal plate 342 are provided with grooves for the limiting protrusion 362 to pass through. When the pillow body 1 moves along the sliding saddle driven by the lead screw 23, the top plate 33 guide frame 36 slides. At this time, the flip rod 322 will move along the limiting rail 323. As it moves, the limiting protrusion 362 will squeeze the pad 35, so that the pad 35 enters between the top plate 33 and the horizontal plate 342 for support. Then the flip rod 322 will slide into the tilting part 3231, driving the rotating sleeve 32 to flip.

[0046] Preferably, the groove on the top plate 33 is provided with an angle 334. When the pad 35 moves past the limiting protrusion 362 with the movement of the pillow 1, the weight of the pillow 1 and the pushing force of the hydraulic cylinder 31 squeeze the pad 35, causing the pad 35 to slide away from the support ball 331 along the angle 334 and reset, thus completing the flipping action of the rotating sleeve 32.

[0047] In another embodiment of the present invention, the length of the limiting protrusion 362 can be Figure 12 and Figure 13 The two states shown Figure 12 In the middle, the length of the limiting protrusion 362 is short. At this time, the pad 35 is briefly squeezed between the top plate 33 and the horizontal plate 342, providing a supporting effect during the process of the rotating sleeve 32 flipping and tilting. Figure 13 In the middle, the length of the limiting protrusion 362 is long, spanning the lower half of the guide frame 36. When the length of the limiting protrusion 362 is long, the pad 35 is continuously squeezed between the top plate 33 and the horizontal plate 342. At this time, the supporting force of the rotating sleeve 32 is evenly distributed by the pad 35. The supporting force given by the support in the inclined state is weakened, and the vibration reduction capacity decreases. However, the pad 35 continuously distributes the supporting force evenly, preventing damage.

[0048] In another embodiment of the present invention, a piezoelectric ceramic sheet 330 is provided between the top plate 33 and the support ball 331. The piezoelectric ceramic sheet 330 can detect the pressure value between the top plate 33 and the top sleeve 34. A damping system is provided on the slide saddle. When the piezoelectric ceramic sheet 330 detects that the pressure value between the top plate 33 and the top sleeve 34 fluctuates greatly due to cutting, the damping system will dampen the pillow body 1, thereby alleviating vibration and avoiding the phenomenon of blade marks on the surface of the workpiece.

[0049] The damping system can push the hydraulic components against the connecting block that is slidably connected to the slide saddle. The connecting block is damped by fitting against the plane on the pillow body 1, and lubricating oil can be applied to the fitting surface.

[0050] During the hoisting of the pillow body 1, firstly, the sealing plate at the upper end of the guide frame 36 is removed, and then fixed to the top of the pillow body 1 with ropes. The pillow body 1 is then hoisted, and after hoisting, it is aligned with the sliding saddle. The output end of the hydraulic cylinder 31 is then driven to extend and press against the top plate 33. After guiding, the hydraulic cylinder 31 is gradually moved down until the screw nut 24 is fixed in position for installation. Then, without driving the screw 23, the hydraulic cylinder 31 is driven to retract. At this time, the rotating sleeve 32 is installed on the hemispherical sleeve 341 and the output end of the hydraulic cylinder 31 for use. The installation is completed. When it is necessary to drive the pillow body 1 to move along the Z-axis, the output end of the hydraulic cylinder 31 maintains pressure and the weight of the pillow body 1. The counterweight reduces the load on the lead screw 23 and lead screw nut 24, linear roller guide 11 and slider 111, thus maintaining the stability of the mating surface. As the pillow 1 moves along the pillow 1, the limiting protrusion 362 will squeeze the pad 35, causing the pad 35 to enter between the top plate 33 and the horizontal plate 342 for support. Then the flipping rod 322 will slide into the tilting part 3231, driving the rotating sleeve 32 to flip, so that the vertical support of the rotating sleeve 32 moves to the tilting support. At this time, the vibration in the direction of the two hydraulic cylinders 31 will be relieved by the tilted rotating sleeve 32 after flipping, thereby relieving the vibration caused by the excessive extension of the pillow 1.

[0051] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A dual-drive Z-axis ram structure, comprising a ram body (1) slidably connected to a saddle, wherein a linear roller guide rail (11) is provided diagonally between the ram body (1) and the saddle, characterized in that, The pillow body (1) is respectively provided with: Z-axis drive assembly (2) includes a lead screw (23) symmetrically arranged along the central axis of the pillow body (1), and a lead screw nut (24) fixedly connected to the slide saddle on the lead screw (23). The force equalization mechanism (3) includes a hydraulic cylinder (31) that is opposite to the lead screw (23) and symmetrically arranged along the central axis of the pillow body (1). The pillow body (1) is symmetrically provided with a top plate (33) corresponding to the hydraulic cylinder (31).

2. The dual-drive Z-axis slide ram structure according to claim 1, characterized in that, A support ball (331) is provided on the top plate (33), and a top sleeve (34) is provided on the output end of the hydraulic cylinder (31). A hemispherical sleeve (341) corresponding to the support ball (331) is provided on the top sleeve (34).

3. The dual-drive Z-axis slide ram structure according to claim 2, characterized in that, A rotating sleeve (32) is rotatably connected to the hemispherical sleeve (341). The rotating sleeve (32) supports the supporting ball (331). The rotating sleeve (32) extends with the pillow body (1) and flips along the plane parallel to the central axis.

4. The dual-drive Z-axis slide ram structure according to claim 3, characterized in that, The saddle is provided with a limiting rail (323), the rotating sleeve (32) is provided with a flip bar (322) slidably connected to the limiting rail (323), and the limiting rail (323) is provided with an inclination part (3231).

5. The dual-drive Z-axis slide ram structure according to claim 2, characterized in that, A horizontal plate (342) is provided on the top sleeve (34), and a pad (35) is slidably connected on the horizontal plate (342). The pad (35) is driven to slide between the top plate (33) and the horizontal plate (342).

6. The dual-drive Z-axis slide ram structure according to claim 1, characterized in that, The hydraulic cylinder (31) is provided with a guide frame (36), and the top plate (33) is slidably connected to the guide frame (36).

7. The dual-drive Z-axis slide ram structure according to claim 6, characterized in that, A pad (35) is slidably connected in the top sleeve (34) of the hydraulic cylinder (31), and a limiting protrusion (362) is provided on the guide frame (36). The pad (35) moves with the pillow body (1), so that the limiting protrusion (362) squeezes the pad (35) to move.

8. The dual-drive Z-axis slide ram structure according to claim 5, characterized in that, The top plate (33) has an oblique angle (334), and the pad (35) slides away from the support ball (331) along the oblique angle (334) with the weight of the pillow body (1).

9. The dual-drive Z-axis slide ram structure according to claim 1, characterized in that, The linear roller guide (11) and the lead screw (23) are arranged on the same plane.

10. A dual-drive Z-axis slide ram structure according to claim 7, characterized in that, A sealing plate is provided at the upper end of the guide frame (36), and the top sleeve (34) extends past the sealing plate along with the hydraulic cylinder (31) to adapt for hoisting.

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