Numerical control gantry machine tool beam anti-deformation device

Abstract

The present application relates to the technical field of machine tool beam, and particularly relates to a numerical control gantry machine tool beam anti-deformation device, which comprises a beam, two symmetrical top connecting pieces are rotatably installed on the top of the inner cavity of the beam, two symmetrical bottom connecting pieces are rotatably installed on the bottom of the inner cavity of the beam, the distance between the two bottom connecting pieces is smaller than the distance between the two top connecting pieces, an adjustable tensioning assembly is installed between the bottom connecting piece and the adjacent top connecting piece, the two top connecting pieces are located at the two ends of the beam, and the two bottom connecting pieces are located at the middle of the beam; the present application applies oblique upward tension to the beam through the top connecting piece, the bottom connecting piece and the tensioning assembly, the tension is decomposed into vertical upward force and horizontal force, the vertical force can offset the gravity of the middle part of the beam, thereby reducing the downward bending deformation of the beam, and the purpose of anti-deformation is achieved.

Description

Technical Field

[0001] This invention relates to the field of machine tool beam technology, specifically to a crossbeam anti-deformation device for a CNC gantry milling machine. Background Technology

[0002] Currently, the crossbeam structure of most gantry machine tools is made of square tubing or aluminum profiles (with reinforcing ribs running through the crossbeam but lacking longitudinal mesh reinforcing ribs). Due to the combined weight of the crossbeam itself and the weight of the Z-axis sliding module, the crossbeam will bend downwards and become damaged. Since the weight of the Z-axis sliding module is generally between 200kg and 2000kg, and the stroke is generally between 200-2000mm, due to the multiple effects of the structure and lever arm, even if the crossbeam undergoes micron-level deformation in the X, Y, and Z directions, this three-dimensional micron-level error may be amplified to the millimeter-level deformation error at the machining tool, which will degrade the machining accuracy and working effect of the machine tool, reduce the accuracy and service life of the machine tool. To address this, we designed a counter-deformation device to reduce the bending deformation of the crossbeam.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to design a counter-deformation device that can apply a reverse vertical upward force to the crossbeam to reduce the downward bending deformation of the crossbeam, thereby solving the above-mentioned shortcomings in the technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a crossbeam anti-deformation device for a CNC gantry milling machine, comprising a crossbeam, wherein two symmetrically distributed top connectors are rotatably installed at the top of the inner cavity of the crossbeam, and two symmetrically distributed bottom connectors are rotatably installed at the bottom of the inner cavity of the crossbeam, the distance between the two bottom connectors is smaller than the distance between the two top connectors, and an adjustable tensioning assembly is installed between the bottom connectors and the adjacent top connectors, wherein the two top connectors are located at both ends of the crossbeam, and the two bottom connectors are located in the middle of the crossbeam;

[0006] By adjusting the tensioning assembly, a tension force is applied to the bottom connector toward the top connector. This tension force is decomposed into a vertical force and a horizontal force, with the vertical force exerting an upward force on the crossbeam.

[0007] Preferably, the tensioning assembly includes a first steel cable fixedly installed on the top connector, a first connecting rod fixedly installed at the end of the first steel cable, a second steel cable fixedly installed on the bottom connector, an elastic member fixedly installed at the end of the second steel cable, a threaded rod fixedly installed on the elastic member, and a nut threadedly connected to the threaded rod. The threaded rod passes through the first connecting rod and is slidably connected to the first connecting rod, and the nut is in contact with the side wall of the first connecting rod.

[0008] Preferably, the number of the first steel cable and the second steel cable is set to two, and they are symmetrically installed on the top connector and the bottom connector. The elastic member includes a second connecting rod fixedly installed on the two second steel cables, a plurality of tension springs fixedly installed on the second connecting rod, and a third connecting rod fixedly installed at the ends of the plurality of tension springs. The threaded rod is fixedly connected to the side wall of the third connecting rod.

[0009] Preferably, a sliding rod is also fixedly installed on the third connecting rod, the sliding rod passing through the first connecting rod and slidably connected to the first connecting rod.

[0010] Preferably, a worm gear is fixedly installed on the top connector, a drive shaft is rotatably installed inside the crossbeam, a worm gear meshing with the worm gear is fixedly installed on the drive shaft, a guide roller is fixedly installed on the drive shaft, the guide roller has two spiral grooves with opposite directions of rotation and connected ends, a sliding groove is opened on the top of the crossbeam along the length direction, a drive rod is slidably installed in the sliding groove and spiral groove, and the distance between the two elastic members is greater than the length of the guide roller.

[0011] Preferably, the two second steel cables are located on both sides of the guide roller, the distance between the two second connecting rods is greater than the length of the guide roller, and the elastic element is located at the top of the drive shaft and does not contact the outer peripheral surface of the drive shaft.

[0012] Preferably, the ends where the two spiral grooves connect are at the exact center of the crossbeam.

[0013] Preferably, the helix angle of the spiral groove is greater than its equivalent friction angle.

[0014] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0015] 1. Since the two ends of the crossbeam are fixed and there is no support in the middle, the middle part is prone to bending and deforming downward under its own weight, which affects its accuracy and stability. However, the present invention applies an upward tension force to the crossbeam through the top connector, bottom connector and tensioning assembly. This tension force is decomposed into a vertical upward force and a horizontal force. The vertical force can counteract the weight of the middle part of the crossbeam, thereby reducing the downward bending deformation of the crossbeam and achieving the purpose of anti-deformation.

[0016] 2. Since a Z-axis sliding module is usually slidably installed on the crossbeam for production and processing, the deformation of the crossbeam is greater when the Z-axis sliding module moves to the middle of the crossbeam than when it moves to the ends of the crossbeam. This invention uses the Z-axis sliding module to drive the top connector to rotate synchronously when it moves. When the Z-axis sliding module moves from the ends of the crossbeam to the middle, the tension generated by the second steel cable gradually increases, and when the Z-axis sliding module moves from the middle of the crossbeam to the ends, the tension generated by the second steel cable gradually decreases, thereby dynamically eliminating the gravitational deformation caused by the position of the Z-axis sliding module.

[0017] 3. At the same time, during the use of this invention, due to the design of the worm gear and worm, when the Z-axis sliding module stops moving on the crossbeam, the tension generated by the second steel cable cannot drive the Z-axis sliding module to move in the opposite direction through the top connector, thereby achieving the purpose of self-locking and avoiding the tension that prevents the crossbeam from deforming and affecting the normal use of the Z-axis sliding module.

[0018] 4. When the accuracy changes due to thermal expansion and contraction, the tension component can be adjusted to adjust the tension; and after long-term use, when the crossbeam sags and bends, the amount of sag can also be adjusted by adjusting the tension. 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 overall structure of the present invention;

[0021] Figure 2 This is a cross-sectional view of the beam of the present invention;

[0022] Figure 3 This is a schematic diagram showing the distribution of the transmission shaft and elastic element of the present invention;

[0023] Figure 4 This is a schematic diagram of the tensioning component of the present invention;

[0024] Figure 5 For the present invention Figure 2 A schematic diagram of the structure of part A.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Crossbeam; 2. Top connector; 3. Bottom connector; 4. Tensioning assembly; 4a. First steel cable; 4b. First connecting rod; 4c. Second steel cable; 4d. Elastic component; 4d1. Second connecting rod; 4d2. Tension spring; 4d3. Third connecting rod; 4e. Threaded rod; 4f. Nut; 5. Sliding rod; 6. Worm gear; 7. Drive shaft; 8. Worm; 9. Guide roller; 10. Spiral groove; 11. Slide groove; 12. Drive rod. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0029] This invention provides, for example Figure 1-5The diagram illustrates a crossbeam anti-deformation device for a CNC gantry milling machine, comprising a crossbeam 1. Top connectors 2 are rotatably mounted at the top of both ends of the inner cavity of the crossbeam 1, and two bottom connectors 3 are rotatably mounted at the bottom of the middle of the inner cavity of the crossbeam 1. The two top connectors 2 and the two bottom connectors 3 are symmetrically distributed, forming an inverted isosceles trapezoid. Two symmetrically distributed first steel cables 4a are fixedly mounted on the top connectors 2, and the ends of the two first steel cables 4a are jointly fixedly mounted with a first... A connecting rod 4b has a threaded rod 4e and a sliding rod 5 slidably mounted inside it. A nut 4f is threaded onto the threaded rod 4e. A third connecting rod 4d3 is fixedly mounted at the ends of the threaded rod 4e and the sliding rod 5. Multiple tension springs 4d2 are fixedly mounted on the third connecting rod 4d3. A second connecting rod 4d1 is fixedly mounted at the ends of the multiple tension springs 4d2. The second connecting rod 4d1, the tension springs 4d2, and the third connecting rod 4d3 constitute an elastic element 4d. The second connecting rod 4d1 and the third connecting rod 4d... The greater the distance between the three connecting rods 4d1 and 3, the greater the elastic force generated by the deformation of the tension spring 4d2. Two symmetrically distributed second steel cables 4c are fixedly installed between the second connecting rod 4d1 and the bottom connecting member 3. Here, the first steel cable 4a, the second steel cable 4c, the elastic member 4d, the threaded rod 4e, and the nut 4f constitute an adjustable tensioning assembly 4. By tightening the nut 4f, the length of the threaded rod 4e extending beyond the first connecting rod 4b increases, reducing the distance between the first connecting rod 4b and the third connecting rod 4d3, thus stretching the tension spring 4d2. The tension spring 4d2 generates elastic force to straighten the first steel cable 4a and the second steel cable 4c into a straight line. The second steel cable 4c generates a tension force on the first steel cable 4a. This tension force can be decomposed into a vertically upward force located in the middle of the crossbeam 1 and a horizontal force. Since the middle of the crossbeam 1 is unsupported, it will undergo a slight downward deformation under the action of gravity, resulting in a decrease in the accuracy and stability of the crossbeam 1. This vertically upward force located in the middle of the crossbeam 1 can offset part of the gravity in the middle of the crossbeam 1, thereby reducing deformation and achieving the purpose of anti-deformation.

[0030] Meanwhile, due to the different positions of the existing Z-axis sliding modules moving on the crossbeam 1, the amount of deformation caused by the torque due to gravity varies depending on the position of the Z-axis sliding modules. The deformation is most obvious in the middle of the crossbeam 1, while the deformation at both ends is less. Therefore, we have opened a groove 11 along the length of the crossbeam 1 at the top of the crossbeam 1, and a slide rod 5 is slidably installed in the groove 11. This slide rod 5 is installed on the existing Z-axis sliding modules and moves horizontally synchronously. Alternatively, a sliding rod can be fixedly installed on the top of the slide rod 5 and slidably installed on the top of the crossbeam 1. The mounting base is used to mount the Z-axis sliding module. A drive shaft 7 is rotatably mounted inside the crossbeam 1. A guide roller 9 is fixedly mounted in the middle of the drive shaft 7. The guide roller 9 has two helical grooves 10 with opposite directions of rotation and connected ends. The helix angle of the helical grooves 10 is greater than its equivalent friction angle, and the end of the slide rod 5 is located inside the helical groove 10. A worm gear 6 is fixedly mounted on the top connector 2, and a worm 8 that meshes with the worm gear 6 is fixedly mounted on the drive shaft 7. Thus, when the Z-axis sliding module drives the slide rod 5 from the crossbeam 1... As the end moves towards the center, the slide bar 5 gradually drives the guide roller 9 to rotate through the spiral groove 10. The guide roller 9 drives the worm 8 to rotate through the transmission shaft 7. The worm 8 drives the worm wheel 6 to rotate, and the worm wheel 6 drives the top connector 2 to rotate. This causes the first steel cable 4a to gradually wrap around the top connector 2, gradually pulling the first connecting rod 4b away from the second steel cable 4c. The first connecting rod 4b drives the third connecting rod 4d3 through the nut 4f and the threaded rod 4e. The third connecting rod 4d3 gradually stretches the tension spring 4d2 further, applying greater force to the second steel cable 4c. The tension is maximized when the Z-axis sliding module moves to the middle of the crossbeam 1, and gradually decreases as the Z-axis sliding module moves from the middle to both ends of the crossbeam 1. This ensures that the tension value changes continuously with the position of the Z-axis sliding module, dynamically adjusting the anti-deformation force. In addition, the design of the worm gear 6 and worm 8 ensures that when the Z-axis sliding module stops moving for processing, the tension generated by the tensioning component 4 cannot pull the worm gear 6 to rotate, thus achieving a self-locking function and not affecting the processing of the Z-axis sliding module.

[0031] When using this anti-deformation device, firstly rotate the nut 4f to adjust the length of the tension spring 4d2, thereby initially adjusting the tension of the second steel cable 4c. This ensures that the downward bending deformation caused by its own weight is eliminated when there is no Z-axis sliding module on the crossbeam 1. Then, when the Z-axis sliding module moves from one end to the other in the extension direction on the crossbeam 1, it will drive the top connector 2 to rotate accordingly, so that the tension of the first steel cable 4a gradually increases to the peak value and then gradually decreases to recover.

[0032] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application.

Claims

1. A crossbeam anti-deformation device for a CNC gantry milling machine, comprising a crossbeam (1), characterized in that: Two symmetrically distributed top connectors (2) are rotatably installed at the top of the inner cavity of the crossbeam (1), and two symmetrically distributed bottom connectors (3) are rotatably installed at the bottom of the inner cavity of the crossbeam (1). The distance between the two bottom connectors (3) is smaller than the distance between the two top connectors (2). An adjustable tensioning assembly (4) is installed between the bottom connectors (3) and the adjacent top connectors (2). The two top connectors (2) are located at both ends of the crossbeam (1), and the two bottom connectors (3) are located in the middle of the crossbeam (1). The tensioning assembly (4) includes a first steel cable (4a) fixedly installed on the top connector (2), a first connecting rod (4b) fixedly installed at the end of the first steel cable (4a), a second steel cable (4c) fixedly installed on the bottom connector (3), an elastic member (4d) fixedly installed at the end of the second steel cable (4c), a threaded rod (4e) fixedly installed on the elastic member (4d), and a nut (4f) threadedly connected to the threaded rod (4e). The threaded rod (4e) passes through the first connecting rod (4b) and is slidably connected to the first connecting rod (4b). The nut (4f) is in contact with the side wall of the first connecting rod (4b). A worm gear (6) is fixedly installed on the top connector (2), a drive shaft (7) is rotatably installed inside the crossbeam (1), a worm (8) that meshes with the worm gear (6) is fixedly installed on the drive shaft (7), a guide roller (9) is fixedly installed on the drive shaft (7), two spiral grooves (10) are opened on the guide roller (9), the two spiral grooves (10) have opposite directions of rotation and their ends are connected, a sliding groove (11) is opened on the top of the crossbeam (1) along the length direction, a drive rod (12) is slidably installed in the sliding groove (11) and the spiral groove (10), and the distance between the two elastic members (4d) is greater than the length of the guide roller (9); By adjusting the tensioning assembly (4), a tension force is applied to the bottom connector (3) toward the top connector (2). This tension force is decomposed into a vertical force and a horizontal force, and the vertical force applies an upward force to the crossbeam (1).

2. The anti-deformation device for the crossbeam of a CNC gantry milling machine according to claim 1, characterized in that: The number of the first steel cable (4a) and the second steel cable (4c) is set to two, and they are symmetrically installed on the top connector (2) and the bottom connector (3). The elastic member (4d) includes a second connecting rod (4d1) fixedly installed on the two second steel cables (4c), a plurality of tension springs (4d2) fixedly installed on the second connecting rod (4d1), and a third connecting rod (4d3) fixedly installed at the ends of the plurality of tension springs (4d2). The threaded rod (4e) is fixedly connected to the side wall of the third connecting rod (4d3).

3. The anti-deformation device for the crossbeam of a CNC gantry milling machine according to claim 2, characterized in that: A slide rod (5) is also fixedly installed on the third connecting rod (4d3). The slide rod (5) passes through the first connecting rod (4b) and is slidably connected to the first connecting rod (4b).

4. The anti-deformation device for the crossbeam of a CNC gantry milling machine according to claim 2, characterized in that: The two second steel cables (4c) are located on both sides of the guide roller (9), the distance between the two second connecting rods (4d1) is greater than the length of the guide roller (9), and the elastic element (4d) is located on the top of the drive shaft (7) and does not contact the outer peripheral surface of the drive shaft (7).

5. The anti-deformation device for the crossbeam of a CNC gantry milling machine according to claim 1, characterized in that: The two spiral grooves (10) are connected at the very center of the crossbeam (1).

6. The anti-deformation device for the crossbeam of a CNC gantry milling machine according to claim 5, characterized in that: The helix angle of the spiral groove (10) is greater than its equivalent friction angle.

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