Transverse deformation device for cross beam of numerical control gantry machine tool

Abstract

The invention relates to the technical field of machine tool cross beams, in particular to a numerical control gantry machine tool cross beam anti-deformation device which comprises a cross beam, two symmetrically-distributed top connecting pieces are rotationally installed at the top of an inner cavity of the cross beam, and two symmetrically-distributed bottom connecting pieces are rotationally installed at the bottom of the inner cavity of the cross beam. The distance between the two bottom connecting pieces is smaller than that between the two top connecting pieces, tensioning assemblies with adjustable tightness are installed between the bottom connecting pieces and the adjacent top connecting pieces, the two top connecting pieces are located at the two ends of the cross beam, and the two bottom connecting pieces are located in the middle of the cross beam. According to the invention, through the top connecting piece, the bottom connecting piece and the tensioning assembly, an obliquely upward pulling force is applied to the cross beam, the pulling force is decomposed into a vertically upward force and a horizontal force, and the vertical force can offset the gravity of the middle part of the cross beam, so that the downward bending deformation of the cross beam is reduced, and the purpose of reversible deformation is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of machine tool beams, and in particular to an anti-deformation device for a CNC gantry machine tool beam. Background Art

[0002] Currently, the crossbeam structures of gantry machine tools are mostly square tube and aluminum profile structures (with reinforcing ribs running through the crossbeam but lacking longitudinal mesh reinforcement). The combined weight of the crossbeam and the gravity of the Z-axis slide module can cause the crossbeam to bend downward and become damaged. Since the Z-axis slide module generally weighs between 200kg and 2000kg and has a stroke of 200-2000mm, due to the multiple effects of the structure and the lever arm, even if the crossbeam undergoes micron-level deformation in the X, Y, and Z directions, these micron-level errors in these three directions may be magnified to produce millimeter-level deformation errors at the machining tool, which will deteriorate the machining accuracy and working performance of the machine tool, reducing the machine tool's accuracy and service life. To this end, we have designed an anti-deformation device to counteract the reaction force of the crossbeam and reduce the bending deformation of the beam.

[0003] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0004] The purpose of the present invention is to design an anti-deformation device that can apply a reverse vertical upward force to the beam to reduce the amplitude of the downward bending deformation of the beam, so as to solve the above-mentioned shortcomings in the technology.

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

[0006] By adjusting the tensioning assembly, a pulling force is applied to the bottom connecting member toward the top connecting member. The pulling force is decomposed into a vertical force and a horizontal force. The vertical force applies an upward force to the beam.

[0007] Preferably, the tensioning assembly includes a first steel cable fixedly mounted on the top connecting member, a first connecting rod fixedly mounted on the end of the first steel cable, a second steel cable fixedly mounted on the bottom connecting member, an elastic member fixedly mounted on the end of the second steel cable, a threaded rod fixedly mounted 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 cables and the second steel cables is set to two, and they are symmetrically installed on the top connecting member and the bottom connecting member. 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 with the ends of the plurality of tension springs fixedly installed. The threaded rod is fixedly connected to the side wall of the third connecting rod.

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

[0010] Preferably, a worm gear is fixedly mounted on the top connecting member, a transmission shaft is rotatably mounted in the crossbeam, a worm meshing with the worm gear is fixedly mounted on the transmission shaft, a guide roller is fixedly mounted on the transmission shaft, two spiral grooves are provided on the guide roller, the two spiral grooves have opposite rotation directions and the ends are connected, a slide groove is provided on the top of the crossbeam along the length direction, a transmission rod is slidably mounted in the slide groove and the spiral groove, and the spacing between the two elastic members is greater than the length of the guide roller.

[0011] Preferably, the two second steel cables are respectively 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 member is located at the top of the transmission shaft and does not contact the outer circumference of the transmission shaft.

[0012] Preferably, the end where the two spiral grooves are connected is in the middle of the beam.

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

[0014] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0015] 1. Since the two ends of the beam are fixed and there is no support in the middle, the middle part is easily bent and deformed downward due to its own gravity, which affects its own accuracy and stability. However, the present invention applies an oblique upward pulling force to the beam through the top connecting member, the bottom connecting member and the tensioning assembly. This pulling force is decomposed into a vertical upward force and a 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 achieving the purpose of anti-deformation.

[0016] 2. Since a Z-axis sliding module is usually slidably mounted on the beam for production and processing, the deformation of the beam is greater when the Z-axis sliding module moves to the center of the beam than when it moves to the ends of the beam. In the present invention, the Z-axis sliding module drives the top connecting member to rotate synchronously when it moves, so that when the Z-axis sliding module moves from the ends of the beam to the center, the tension generated by the second steel cable gradually increases, and when the Z-axis sliding module moves from the center of the beam to the ends, the tension generated by the second steel cable correspondingly gradually decreases, thereby dynamically eliminating the gravity deformation caused by the position of the Z-axis sliding module;

[0017] 3. At the same time, during use of the present 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 preventing the tension that prevents the deformation of the crossbeam from affecting the normal use of the Z-axis sliding module;

[0018] 4. When the accuracy changes due to thermal expansion and contraction, the tensioning component can also be adjusted to adjust the tension; and after long-term use, when the beam sags and bends, the amount of sag can also be adjusted by adjusting the tension. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

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

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

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

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

[0025] Description of reference numerals:

[0026] 1. Crossbeam; 2. Top connecting piece; 3. Bottom connecting piece; 4. Tensioning assembly; 4a. First steel cable; 4b. First connecting rod; 4c. Second steel cable; 4d. Elastic member; 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 DESCRIPTION

[0027] In order to help those skilled in the art 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 embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of this application.

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0029] The present invention provides Figure 1-5The crossbeam anti-deformation device of a CNC gantry machine tool shown in the figure comprises a crossbeam 1, top connectors 2 are rotatably mounted on the tops of both ends of the inner cavity of the crossbeam 1, and two bottom connectors 3 are rotatably mounted on the bottom in the middle of the inner cavity of the crossbeam 1. The two top connectors 2 are symmetrically distributed, and the two bottom connectors 3 are also symmetrically distributed. The two top connectors 2 and the two bottom connectors 3 form an inverted isosceles trapezoid shape. Two symmetrically distributed first steel cables 4a are fixedly mounted on the top connector 2, and the ends of the two first steel cables 4a are jointly fixedly mounted with first The connecting rod 4b has a threaded rod 4e and a sliding rod 5 passing through and slidingly installed in the first connecting rod 4b. The threaded rod 4e is threadedly connected with a nut 4f. At the same time, the ends of the threaded rod 4e and the sliding rod 5 are fixedly installed with a third connecting rod 4d3. A plurality of tension springs 4d2 are fixedly installed on the third connecting rod 4d3. The ends of the plurality of tension springs 4d2 are fixedly installed with a second connecting rod 4d1. The second connecting rod 4d1, the tension spring 4d2 and the third connecting rod 4d3 constitute an elastic member 4d. The second connecting rod 4d1 and the third connecting rod 4d 3, the greater the distance between them, the greater the elastic force generated by the deformation of the tension spring 4d2, and 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 out of the first connecting rod 4b can be lengthened, so that the distance between the first connecting rod 4b and the third connecting rod 4d3 becomes smaller, pulling the tension spring 4d2 to stretch. The tension spring 4d2 generates elastic force to straighten the first steel cable 4a and the second steel cable 4c to form a straight line. The second steel cable 4c generates a pulling force toward the first steel cable 4a. This pulling force can be decomposed into a vertical upward force and a horizontal force in the middle of the beam 1. Since the middle of the beam 1 has no support, it will produce a slight downward deformation under the action of gravity, resulting in a deterioration in the accuracy and stability of the beam 1. This vertical upward force in the middle of the beam 1 can offset part of the gravity in the middle of the beam 1, thereby reducing the deformation and achieving the purpose of anti-deformation.

[0030] At the same time, due to the different positions of the existing Z-axis sliding module moving on the beam 1, the amount of deformation caused by the torque generated by gravity varies with the position of the Z-axis sliding module. The deformation generated in the middle of the beam 1 is the most obvious, while the deformation at both ends will be less. For this reason, a slide groove 11 is opened at the top of the beam 1 along the length direction of the beam 1. A slide rod 5 is slidably installed in the slide groove 11. This slide rod 5 is installed on the existing Z-axis sliding module and moves horizontally synchronously. A slide rod 5 can also be fixed on the top of the slide rod 5 and slidably installed on the top of the beam 1. The Z-axis sliding module is mounted on the mounting seat, and a transmission shaft 7 is rotatably mounted in the beam 1. A guide roller 9 is fixedly mounted in the middle of the transmission shaft 7. Two spiral grooves 10 are provided on the guide roller 9. The rotation directions of the two spiral grooves 10 are opposite and the ends are connected. The thread lead angle of the spiral groove 10 is greater than its equivalent friction angle, and the end of the slide rod 5 is located in the spiral groove 10. A worm gear 6 is fixedly mounted on the top connecting member 2, and a worm 8 meshing with the worm gear 6 is fixedly mounted on the transmission shaft 7. In this way, when the Z-axis sliding module drives the slide rod 5 from the beam 1 When the end moves toward the middle, the slide rod 5 will gradually drive the guide roller 9 to rotate through the spiral groove 10, the guide roller 9 will drive the worm 8 to rotate through the transmission shaft 7, the worm 8 will drive the worm wheel 6 to rotate, and the worm wheel 6 will drive the top connecting member 2 to rotate, so that the first steel cable 4a will gradually wrap around the top connecting member 2, gradually pulling the first connecting rod 4b away from the second steel cable 4c, the first connecting rod 4b will drive the third connecting rod 4d3 through the nut 4f and the threaded rod 4e, and the third connecting rod 4d3 will gradually stretch the tension spring 4d2 further, exerting greater pressure on the second steel cable 4c. When the Z-axis sliding module moves to the middle of the beam 1, the tension generated reaches the maximum value. When the Z-axis sliding module gradually moves from the middle of the beam 1 to both ends, the tension generated gradually decreases, thereby ensuring that the tension value constantly changes with the position of the Z-axis sliding module and dynamically adjusts the anti-deformation force; coupled with the design of the worm wheel 6 and the worm 8, when the Z-axis sliding module stops moving for processing, the tension generated by the tensioning component 4 cannot pull the worm wheel 6 to rotate, thereby realizing the self-locking function and will not affect the processing of the Z-axis sliding module;

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

[0032] It is important to note that the construction and arrangement of the present application shown in a number of different exemplary embodiments are illustrative only. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should readily understand that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application (e.g., the size, scale, structure, shape and proportion of various components, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientation changes, etc.).

Claims

1. A crossbeam anti-deformation device for a CNC gantry machine tool, comprising a crossbeam (1), characterized in that: Two symmetrically distributed top connecting members (2) are rotatably mounted on the top of the inner cavity of the beam (1), and two symmetrically distributed bottom connecting members (3) are rotatably mounted on the bottom of the inner cavity of the beam (1). The spacing between the two bottom connecting members (3) is smaller than the spacing between the two top connecting members (2). An adjustable tensioning assembly (4) is mounted between the bottom connecting member (3) and the adjacent top connecting member (2). The two top connecting members (2) are located at both ends of the beam (1), and the two bottom connecting members (3) are located in the middle of the beam (1). By adjusting the tensioning assembly (4), a pulling force is applied to the bottom connecting member (3) toward the top connecting member (2), and the pulling force is decomposed into a vertical force and a horizontal force. The vertical force applies an upward force to the beam (1).

2. The anti-deformation device for a CNC gantry machine tool crossbeam according to claim 1, characterized in that: The tensioning assembly (4) comprises a first steel cable (4a) fixedly mounted on the top connecting member (2), a first connecting rod (4b) fixedly mounted on the end of the first steel cable (4a), a second steel cable (4c) fixedly mounted on the bottom connecting member (3), an elastic member (4d) fixedly mounted on the end of the second steel cable (4c), a threaded rod (4e) fixedly mounted 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), and the nut (4f) is in contact with the side wall of the first connecting rod (4b).

3. The anti-deformation device for a CNC gantry machine tool crossbeam according to claim 2, characterized in that: The number of the first steel cables (4a) and the second steel cables (4c) is set to two, and they are symmetrically installed on the top connecting member (2) and the bottom connecting member (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 on 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).

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

5. The anti-deformation device for a CNC gantry machine tool beam according to claim 3, characterized in that: A worm wheel (6) is fixedly mounted on the top connecting member (2), a transmission shaft (7) is rotatably mounted in the crossbeam (1), a worm (8) meshing with the worm wheel (6) is fixedly mounted on the transmission shaft (7), a guide roller (9) is fixedly mounted on the transmission shaft (7), two spiral grooves (10) are provided on the guide roller (9), the two spiral grooves (10) have opposite rotation directions and are connected at their ends, a sliding groove (11) is provided on the top of the crossbeam (1) along the length direction, a transmission rod (12) is slidably mounted in the sliding groove (11) and the spiral groove (10), and the spacing between the two elastic members (4d) is greater than the length of the guide roller (9).

6. The anti-deformation device for a CNC gantry machine tool crossbeam according to claim 5, characterized in that: The two second steel cables (4c) are respectively 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 member (4d) is located at the top of the transmission shaft (7) and does not contact the outer peripheral surface of the transmission shaft (7).

7. The anti-deformation device for a CNC gantry machine tool beam according to claim 5, characterized in that: The end portion where the two spiral grooves (10) communicate is located in the middle of the crossbeam (1).

8. The anti-deformation device for a CNC gantry machine tool beam according to claim 5, characterized in that: The thread lead angle of the spiral groove (10) is greater than its equivalent friction angle.

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