High-precision hierarchical positioning gantry frame and machine tool

Abstract

The application provides a high-precision hierarchical positioning gantry frame and machine tool, which comprises a column, a beam and a hierarchical positioning device. The two columns are arranged along the vertical direction and are horizontally spaced apart by a certain distance. Each column is provided with a lifting mechanism. The two ends of the beam are driven to rise and fall along the vertical direction by the two lifting mechanisms. The two hierarchical positioning devices are used to position the two ends of the beam. The hierarchical positioning device comprises a positioning strip, positioning blocks and a telescopic driving element. The positioning strip is fixed on the column and arranged along the vertical direction. The positioning blocks are arranged along the vertical direction and fixed on the positioning strip in sequence at intervals. The telescopic driving element comprises a first base and a first moving end. The first base is fixed on the end of the beam. The first moving end can advance or retreat relative to the positioning blocks, so that the first moving end abuts against or moves away from the positioning blocks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gantry machine tools, in particular to a high-precision hierarchical positioning gantry frame and machine tool. BACKGROUND

[0002] With the development of the mechanical processing industry, higher requirements are put forward for the machining precision and stability of machine tools. The gantry frame is the main component of the gantry machine tool, and the precision and stability of the gantry frame directly determine the precision and stability of the machine tool.

[0003] For heavy gantry machine tools, the gantry frame is large and heavy in structure. Firstly, the precision of its parts itself cannot be guaranteed by machining. Secondly, due to the precision influence of the transmission mechanism, the precision of the gantry in different machining states is different. Finally, affected by temperature, material quality and load, the precision of the gantry frame fluctuates in real time, resulting in poor stability of the gantry frame and poor machining quality of the machine tool. The improvement of the precision and stability of the gantry frame is a traditional problem, which directly restricts the high-precision development of heavy gantry machine tools. Therefore, it has important application value to develop a high-precision hierarchical positioning gantry frame and machine tool. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a high-precision hierarchical positioning gantry frame and machine tool, which can position the cross beam moving up and down along the column by setting a hierarchical positioning device on the column, thereby improving the precision of the gantry frame.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] A high-precision hierarchical positioning gantry frame comprises:

[0007] Two columns, both of which extend in the vertical direction and are horizontally spaced apart by a certain distance, and an elevating mechanism is arranged on each column;

[0008] A cross beam, both ends of which are driven to rise and fall in the vertical direction by two elevating mechanisms respectively;

[0009] Two hierarchical positioning devices for positioning both ends of the cross beam respectively, the hierarchical positioning device comprising a positioning strip, a positioning block and a telescopic drive, the positioning strip being fixed on the column and arranged in the vertical direction, a plurality of positioning blocks being arranged in the vertical direction and fixed on the positioning strip in turn at a certain distance, the telescopic drive comprising a first base and a first moving end, the first base being fixed on the end of the cross beam, the first moving end being able to advance or retreat relative to the positioning block, so that the first moving end abuts against the positioning block or moves away from the positioning block.

[0010] Further, a connecting beam is arranged, two ends of the connecting beam are fixed on the two columns respectively, a double-output shaft motor is arranged on the column, and the double-output shaft motor synchronously drives the two lifting mechanisms to move through two transmission shafts.

[0011] Further, the lifting mechanism comprises a rotating driving member, a lead screw and a lead screw nut, the rotating driving member is fixed on the column, the lead screw is fixedly connected with an output shaft of the rotating driving member, and the lead screw nut is sleeved on the lead screw and fixed with the end of the cross beam.

[0012] Further, the hierarchical positioning device further comprises a connecting sleeve and a nut seat, the connecting sleeve comprises a first sleeve and a second sleeve which are fixedly connected from bottom to top, the first sleeve is sleeved on the lead screw nut and fixedly connected with the lead screw nut, the second sleeve is sleeved on the lead screw and slidably connected with the lead screw, the nut seat is sleeved on the second sleeve and slidably connected with the second sleeve, and the nut seat is fixedly connected with the end of the cross beam.

[0013] The top of the first sleeve is provided with a resting surface, and the resting surface is used for resting the nut seat.

[0014] Further, the lead screw nut further comprises a safety nut, the safety nut is fixedly connected with the connecting sleeve and sleeved on the lead screw, and the safety nut is arranged below the lead screw nut.

[0015] Further, the hierarchical positioning device further comprises an identification sensor and a plurality of encoding blocks, the encoding blocks are arranged on the positioning strip at intervals in the vertical direction, each encoding block is arranged on one side of the positioning block, and the identification sensor is fixed on the first base and used for identifying the encoding blocks.

[0016] Further, a top-tight telescopic member and a clamping telescopic member are arranged, the cross beam is provided with a guide surface with a machining precision higher than a preset precision threshold, the top-tight telescopic member comprises a second base and a second moving end, the second base is fixed on the cross beam, and the second moving end is abutted against one column which is provided with a close surface capable of closely abutting against the guide surface, a plurality of clamping telescopic members are arranged on both sides of the two columns, the clamping telescopic member comprises a third base and a third moving end, the third base is fixed on the cross beam, and the third moving end is abutted against the column.

[0017] Further, the cross beam is further provided with a torsion beam, the torsion beam comprises a main beam and a vice beam, the axial direction of the main beam is parallel to the axial direction of the cross beam, the vice beam is fixedly arranged with the main beam, a plurality of groups of the vice beam are sequentially arranged at a certain distance along the axial direction of the main beam, each group of the vice beam comprises two vice beams which are symmetrically arranged relative to the main beam, the main beam is arranged at a certain distance from the cross beam, and the two groups of the vice beam at both ends of the main beam are fixedly arranged with the cross beam, and the plurality of groups of the vice beam in the middle of the main beam are all provided with a pushing piece arranged along the radial direction of the cross beam between the main beam and the cross beam, and the pushing piece is used for fine adjustment of the position of the cross beam relative to the vice beam.

[0018] Further, the unloading device is further provided, the unloading device comprises an unloading nut and an unloading telescopic piece, the unloading nut is sleeved on the lead screw, the unloading telescopic piece comprises a fourth base and a fourth telescopic piece, the fourth base is fixed on the unloading nut, and the fourth telescopic piece is fixed with the cross beam.

[0019] A machine tool comprises the high-precision staged positioning gantry frame.

[0020] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0021] The high-precision staged positioning gantry frame and machine tool provided by the present application drive the two ends of the cross beam to move simultaneously through two lifting mechanisms, so that the cross beam moves to a specified height, the first moving end advances relative to the positioning block along the axial direction of the cross beam, so that the first moving end abuts against the positioning block, and the weight of the cross beam is applied to the two positioning blocks, thereby releasing the pressure to the two columns, avoiding the weight of the cross beam being applied to the lifting device, and the staged positioning device can accurately place the cross beam at a specified height, so that the cross beam has very stable horizontal precision. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings described herein are used to provide further understanding of the present application, and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 It is a general layout diagram of the gantry frame of the present application.

[0024] Figure 2 It is a staged positioning device of the cross beam of the present application.

[0025] Figure 3 It is a schematic diagram of the back structure of the cross beam of the present application.

[0026] Figure 4 It is a design diagram of the lead screw nut of the present application.

[0027] Figure 5 Flow chart of beam grading motion of the present application.

[0028] Design diagram of torsion beam of the present application.

[0029] Figure 7 Schematic diagram of torsion beam precision correction method of the present application.

[0030] Figure 8 Design diagram of unloading device of the present application.

[0031] Figure 9 Schematic diagram of beam reverse deformation curve of the present application.

[0032] Figure 10 Schematic diagram of column reverse deformation curve of the present application.

[0033] Wherein, 100, gantry frame main structure; 101, first column; 102, second column; 103, connecting beam; 104, beam; 1041, guide surface; 105, slide; 106, tool holder; 107, speed reducer; 108, double output shaft motor; 109, transmission shaft; 110, lead screw; 111, lead screw nut;

[0034] 200, grading positioning device; 201, positioning strip; 202, positioning block; 203, telescopic driving part; 2031, first base; 2032, first moving end; 204, connecting sleeve; 2041, first sleeve; 20411, resting surface; 2042, second sleeve; 205, nut seat; 2051, first lubricating oil hole; 2052, second lubricating oil hole; 2053, lubricating oil pipe; 2054, through hole; 206, safety nut; 207, distance sensor; 208, identification sensor; 209, encoding block; 2010, photoelectric sensor;

[0035] 300, torsion beam; 301, top-up telescopic part; 3011, second base; 3012, second moving end; 302, clamping telescopic part; 3021, third base; 3022, third moving end; 303, main beam; 304, auxiliary beam; 305, pushing part; 306, supporting leg; 307, micrometer; 308, precision marble angle ruler; 309, ram;

[0036] 400, unloading device; 401, unloading nut; 402, unloading telescopic part; 403, fourth base; 404, fourth telescopic part. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0038] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0039] Embodiment 1

[0040] Embodiment 1 provides a high-precision staged positioning gantry frame for a gantry machine tool. The high-precision staged positioning gantry frame provided by the embodiment includes a gantry frame main structure 100, as shown in Figure 1 The gantry frame main structure 100 includes two columns, a cross beam 104 arranged between the two columns, and two staged positioning devices 200. The main structure of the gantry frame is formed by the two columns and the cross beam 104. The two ends of the cross beam 104 are each positioned and supported by one of the two staged positioning devices 200, and the accuracy of the cross beam 104 is accurately adjusted.

[0041] As shown in Figure 1 The two columns each extend in the vertical direction and are arranged at a certain distance apart in the horizontal direction. Each column is provided with a lifting mechanism. The two columns are respectively a first column 101 and a second column 102.

[0042] As shown in Figure 1 The cross beam 104 is arranged on the first column 101 and the second column 102. The two ends of the cross beam 104 are respectively driven to move up and down in the vertical direction by the two lifting mechanisms, so that the cross beam 104 can move up and down in the vertical direction to adapt to workpieces of different heights. A slide 105 is arranged on the cross beam 104 and can move in the horizontal direction. A tool holder 106 is mounted on the slide 105 and used for machining workpieces.

[0043] As shown in Figure 2As shown, two hierarchical positioning devices 200 are used to position the two ends of the cross beam 104 respectively, the hierarchical positioning device 200 can accurately place the cross beam 104 at a specified height, so that the cross beam 104 has very stable horizontal precision, the hierarchical positioning device 200 includes a positioning strip 201, a positioning block 202 and a telescopic drive 203, the positioning strip 201 is fixed on the column and arranged in the vertical direction, a plurality of positioning blocks 202 are arranged in the vertical direction and fixed on the positioning strip 201 in sequence at a certain distance, and the telescopic drive 203 includes a first base 2031 and a first moving end 2032, the first base 2031 is fixed on the end of the cross beam 104, and the first moving end 2032 can advance or retreat relative to the positioning block 202 in the axial direction of the cross beam 104, so that the first moving end 2032 abuts against or moves away from the positioning block 202.

[0044] The high-precision hierarchical positioning gantry frame provided by the embodiment can accurately place the cross beam 104 at a specified height, so that the cross beam 104 has very stable horizontal precision.

[0045] In the embodiment, as shown in the design principle diagram of the hierarchical positioning device 200. Figure 2 The telescopic drive 203 is a telescopic hydraulic cylinder, the telescopic hydraulic cylinder includes a telescopic oil cylinder and a plug, the telescopic oil cylinder is the first base 2031, and the plug is the first moving end 2032, the telescopic oil cylinder is installed on the lower side of the cross beam 104, and the plug is a piston of the telescopic oil cylinder and can perform extension and retraction actions. The positioning strip 201 is fixed on the first column 101 and the second column 102 by screws and pins, a plurality of positioning blocks 202 are arranged in the vertical direction and fixed on the positioning strip 201 in sequence at a certain distance, and the positioning block 202 is embedded in the positioning strip 201. When the plug is extended, the cross beam 104 can be placed on the upper surface of the positioning block 202 through the telescopic oil cylinder and the plug. By polishing the upper surface of the positioning block, the height dimension of the upper surface of the positioning block 202 can be finely controlled, so as to ensure the positioning precision of the cross beam 104 on the first column 101 and the second column 102.

[0046] Embodiment 2

[0047] The high-precision hierarchical positioning gantry frame provided by the embodiment 2 further includes a connecting beam 103, as shown in the design principle diagram of the hierarchical positioning device 200. Figure 1As shown, the two ends of the connecting beam 103 are fixed on the two columns respectively, and in this embodiment, the two ends of the connecting beam 103 are fixed on the top of the two columns respectively, and the double-output shaft motor 108 is arranged on the column, and the double-output shaft motor 108 synchronously drives the two lifting mechanisms to move through the two oppositely arranged transmission shafts 109.

[0048] In this embodiment, as shown in the figure, Figure 1 The lifting mechanism is a lead screw nut mechanism, which includes a rotating drive member, a lead screw 110 and a lead screw nut 111. The lead screw 110 is a ball screw or a T-shaped lead screw. The rotating drive member is fixed on the column, and the lead screw 110 is fixedly connected with the output shaft of the rotating drive member. The lead screw nut 111 is sleeved on the lead screw 110 and fixed with the end of the cross beam 104. The rotating drive member is a speed reducer 107, which not only reduces the speed of the transmission shaft 109, but also converts the movement direction of the transmission shaft 109, i.e. converts the horizontal rotation movement of the transmission shaft 109 into vertical rotation movement, so as to drive the lead screw 110 to rotate in the vertical direction, thereby driving the lead screw nut 111 to move up and down.

[0049] In this embodiment, as shown in the figure, Figure 4 The connecting sleeve 204 includes a first sleeve 2041 and a second sleeve 2042 fixedly connected from bottom to top. The first sleeve 2041 is sleeved on the lead screw nut 111 and fixedly connected with the lead screw nut 111 through screws, so that the lead screw nut 111 is fastened in the first sleeve 2041 and there is no relative movement between the lead screw nut 111 and the first sleeve 2041. The inner diameter of the second sleeve 2042 is slightly larger than the diameter of the lead screw 110. The second sleeve 2042 is sleeved on the lead screw 110 and slidably connected with the lead screw 110. The nut seat 205 is provided with a through hole 2054, and the diameter of the through hole 2054 is slightly larger than the outer diameter of the second sleeve 2042. The nut seat 205 is sleeved on the second sleeve 2042 through the through hole 2054 and slidably connected with the second sleeve 2042. The nut seat 205 is fixedly connected with the end of the cross beam 104. The second sleeve 2042 can slide up and down in the nut seat 205 and cannot rotate relative to the nut seat 205.

[0050] As shown in the figure, Figure 4 The top of the first sleeve 2041 is provided with a resting surface 20411 for resting the nut seat 205. Specifically, the outer diameter of the first sleeve 2041 is larger than the outer diameter of the second sleeve 2042, so that the connection part of the first sleeve 2041 and the second sleeve 2042 is stepped, and the top surface of the first sleeve 2041 is the resting surface 20411.

[0051] During use, when the rotating driving member drives the screw rod 110 to rotate and drive the screw nut 111 to descend, the first sleeve 2041 and the second sleeve 2042 descend with the screw nut 111, and the nut seat 205 descends with the screw nut 111 due to the action of gravity. During the descending process, the nut seat 205 is always placed on the placement surface 20411, and when the cross beam 104 descends to a specified height, the first moving end 2032 advances relative to the positioning block 202 along the axial direction of the cross beam 104, so that the first moving end 2032 abuts against the positioning block 202, and the weight of the cross beam 104 is pressed on the positioning block 202. At this time, the rotating driving member drives the screw rod 110 to rotate and continues to drive the screw nut 111 to descend by a certain distance, and the first sleeve 2041 and the second sleeve 2042 descend with the screw nut 111, so that the second sleeve 2042 moves relative to the nut seat 205 by a certain distance, and the nut seat 205 is separated from the placement surface 20411.

[0052] When the rotating driving member drives the screw rod 110 to rotate and drive the screw nut 111 to ascend, the first sleeve 2041 and the second sleeve 2042 ascend with the screw nut 111, the nut seat 205 is given a certain pressure by the contact between the placement surface 20411 and the nut seat 205, and the nut seat 205 ascends with the screw nut 111. During the ascending process, the nut seat 205 is always placed on the placement surface 20411, and when the cross beam 104 ascends to a specified height, the first moving end 2032 advances relative to the positioning block 202 along the axial direction of the cross beam 104, so that the first moving end 2032 abuts against the positioning block 202, and the weight of the cross beam 104 is pressed on the positioning block 202. At this time, the rotating driving member drives the screw rod 110 to rotate and continues to drive the screw nut 111 to descend by a certain distance, and the first sleeve 2041 and the second sleeve 2042 descend with the screw nut 111, so that the second sleeve 2042 moves relative to the nut seat 205 by a certain distance, and the nut seat 205 is separated from the placement surface 20411.

[0053] When the nut seat 205 is separated from the placement surface 20411, the screw rod 110 is no longer subjected to force at this time, and all the weight of the cross beam 104 is supported by the positioning block 202, so that the connection stiffness and accuracy of the cross beam 104 and the two columns are better.

[0054] In the embodiment, the material of the screw nut 111 is softer than that of the screw rod 110, so that the screw nut 111 is worn during the relative movement of the screw nut 111 and the screw rod 110, the screw rod 110 is prevented from being worn, and the service life of the screw rod 110 is increased. The material of the screw nut 111 can be copper, copper-aluminum alloy, etc.

[0055] In the embodiment, the screw nut 111 and the second sleeve 2042 are fixedly connected through a snap spring and / or a key.

[0056] In this embodiment, as shown in Figure 4 In order to ensure the relative sliding of the second sleeve 2042 and the nut seat 205 and the second sleeve 2042 and the lead screw 110, a first lubricating oil hole 2051, a second lubricating oil hole 2052 and a lubricating oil pipe 2053 are arranged on the nut seat 205, the first lubricating oil hole 2051 is arranged on the threaded seat for the lubricating oil to pass in, the second lubricating oil hole 2052 is arranged in the first through hole 2054 on the inner side of the nut seat 205 for the lubricating oil to be discharged, the first lubricating oil hole 2051 and the second lubricating oil hole 2052 are connected through the lubricating oil pipe 2053, which facilitates the relative sliding of the second sleeve 2042 and the nut seat 205 and the second sleeve 2042 and the lead screw 110, and sealing rings are arranged on both sides of the second lubricating oil hole 2052 to prevent the lubricating oil from leaking.

[0057] As shown in Figure 4 The stepped positioning device 200 further comprises a safety nut 206, which is fixedly connected with the connecting sleeve 204 and is sleeved on the lead screw 110, the safety nut 206 is arranged below the lead screw nut 111, the safety nut 206 and the connecting sleeve 204 cannot rotate relative to each other but can slide relative to each other, the safety nut 206 can support the weight of the cross beam 104 when the lead screw nut 111 fails, thereby playing a safety role. The lead screw 110 is screwed into the lead screw nut 111 and the safety nut 206 at the same time.

[0058] As shown in Figure 4 A distance sensor 207 is arranged between the safety nut 206 and the connecting sleeve 204, which is used to obtain the distance between the safety nut 206 and the connecting sleeve 204. Specifically, the distance sensor 207 is a laser sensor or an infrared sensor, the receiving end and the transmitting end of the distance sensor 207 are arranged on the safety nut 206 and the connecting sleeve 204 respectively and are arranged correspondingly, or the transmitting end and the receiving end are arranged on the safety nut 206 and the connecting sleeve 204 respectively and are arranged correspondingly, when the lead screw nut 111 is worn to a certain extent after use, the distance sensor 207 will detect that the distance becomes smaller to obtain the wear information, and then the wear information will be transmitted to the numerical control system to prompt the replacement of the lead screw nut 111.

[0059] In this embodiment, as shown in Figure 2 In order to ensure that the stepped positioning device 200 can accurately place the cross beam 104 at a specified height, as shown in the figure, a recognition sensor 208 is installed at the bottom of the first base 2031, and a plurality of encoding blocks 209 are arranged on the positioning strip 201 in the vertical direction, the encoding blocks 209 record the accurate position information of the cross beam 104, and the numerical control system can obtain the position information of the encoding blocks 209 through the recognition sensor 208 and judge the position of the cross beam 104 after the stepped movement. A photoelectric sensor 2010 is arranged on the first base 2031 for detecting the extension and retraction action of the bolt.

[0060] Specifically, in use, the identification sensor 208 and the encoding block 209 are implemented by a linear encoder, which includes a scale, a photoelectric sensor and a signal processing part, the identification sensor 208 is the photoelectric sensor, and the encoding block 209 is the scale. The photoelectric sensor obtains position information twice at each grading movement, and after the photoelectric sensor identifies a certain scale through the scale, the control pin is extended. After the control pin is extended, the cross beam 104 will fall and rest on the positioning block 202, and the photoelectric sensor feeds back the scale identified at this time to the numerical control system through the scale again.

[0061] In addition, the scale can also be a grating ruler, which can provide higher measurement accuracy. In addition, in order to prevent interference and errors, the linear encoder will also use some anti-interference compensation, calibration and other techniques and methods.

[0062] In addition, after the numerical control system obtains the position information of the encoding block 209, low head compensation can be performed on the tool holder 106. The compensation can be distinguished according to the different positions of the cross beam 104, further improving the overall accuracy of the gantry frame. The low head compensation is a self-precision compensation function of the numerical control system. When the slide 105 moves left and right on the cross beam 104, the position of the slide 105 (including the tool holder 106 and the slide block 309) in the vertical direction is theoretically unchanged. However, the cross beam 104 is not a perfect straight line, but is uneven, and the trajectory of the slide 105 on the cross beam 104 is "up-up-down-down", which will affect the machining accuracy. The low head compensation is simply to give a retracting instruction to the slide block 309 when the slide 105 is "down", so that the trajectory of the slide block 309 moving at the lowest point tends to a perfect straight line as much as possible.

[0063] Embodiment 3

[0064] The high-precision grading positioning gantry frame provided in Embodiment 3 further includes a connecting beam 103, which further includes a torsion beam 300, such as Figure 3The diagram shows a schematic view of the back structure of the crossbeam 104. A torsion beam 300 is installed on the back of the crossbeam 104. To ensure the connection rigidity between the crossbeam 104 and the two columns, the crossbeam 104 is also equipped with a clamping telescopic component 301 and a clamping telescopic component 302. The crossbeam 104 has a guide surface 1041 with a machining accuracy higher than a preset accuracy threshold, resulting in very high accuracy. The clamping telescopic component 301 includes a second base 3011 and a second moving end 3012. The second base 3011 is fixed to the crossbeam 104, and the second moving end 3012 abuts against a column. This column has a contact surface that can tightly fit with the guide surface 1041. Multiple clamping telescopic components 302 are provided on both sides of the two columns. Each clamping telescopic component 302 includes a third base 3021 and a third moving end 3022. The third base 3021 is fixed to the crossbeam 104, and the third moving end 3022 abuts against the column.

[0065] Specifically, in this embodiment, the top-tightening telescopic member 301 is a top-tightening hydraulic cylinder, the second base 3011 is a top-tightening oil cylinder, the second moving end 3012 is a top-tightening piston, the clamping telescopic member 302 is a clamping oil cylinder, and the second moving end 3012 is a clamping piston.

[0066] During use, after the crossbeam 104 moves up and down to the designated position, the clamping piston will press against the first column 101, making the guide surface 1041 fit tightly against the first column 101. After the fit is complete, multiple clamping cylinders on the back of the crossbeam 104 will simultaneously clamp the first column 101 and the second column 102. At this time, through the clamping telescopic component 302, the graded positioning device 200, and the clamping telescopic component 301, the crossbeam 104 is tightly connected and accurately positioned with the first column 101 and the second column 102 in the front-back direction, the up-down direction, and the left-right direction, respectively, with excellent overall precision and rigidity.

[0067] like Figure 5 The diagram shows the flow chart of the graded motion of the crossbeam 104. After the graded motion of the crossbeam is completed, it reaches the initial state: the tightening and clamping telescopic components clamp the two columns, the connecting sleeve and nut seat disengage, and the crossbeam rests completely on the positioning block. The graded motion of the crossbeam specifically includes the following steps:

[0068] Step 1: The CNC system issues a command to lift the crossbeam, simultaneously tightening and loosening the telescopic components;

[0069] Step 2: After the expansion joint is tightened and the pressure of the expansion joint is in place, the lead screw rotates, and the connecting sleeve and the nut seat are engaged.

[0070] Step 3: Once the photoelectric sensor is in position, the crossbeam rises slightly by a certain distance (10mm to 20mm) and moves away from the positioning block;

[0071] Step 4: Identify sensor in place, retract first moving end in telescopic drive;

[0072] Step 5: Photoelectric sensor in place, crossbeam lifting according to command until specified position;

[0073] Step 6: Identify sensor in place, extend first moving end in telescopic drive;

[0074] Step 7: Photoelectric sensor in place, crossbeam slightly lowered by a certain distance (10mm to 20mm), contact positioning block;

[0075] Step 8: Identify sensor in place, screw rod rotates, connecting sleeve and nut seat disengages, crossbeam completely rests on positioning block;

[0076] Step 9: Photoelectric sensor in place, screw rod stops rotating;

[0077] Step 10: Tighten telescopic part;

[0078] Step 11: Delay for a certain period of time, clamp telescopic part to clamp two uprights;

[0079] Step 12: Tighten telescopic part, clamp telescopic part pressure in place, crossbeam completes stepwise movement and reaches initial state: tighten telescopic part, clamp telescopic part, connecting sleeve and nut seat disengages, crossbeam completely rests on positioning block.

[0080] In this embodiment, as shown in Figures 6(a)-6(c) The torsion beam 300 includes a main beam 303 and a vice beam 304, and the torsion beam 300 is a high-rigidity structural member welded by the main beam 303, the vice beam 304 and the supporting foot 306. The axial direction of the main beam 303 is parallel to the axial direction of the crossbeam 104. The vice beam 304 is fixedly arranged with the main beam 303. A plurality of groups of vice beams 304 are arranged at intervals along the axial direction of the main beam 303. Each group of vice beams 304 includes two vice beams 304 symmetrically arranged relative to the main beam 303. The main beam 303 is arranged at an interval from the crossbeam 104. The two groups of vice beams 304 at the two ends of the main beam 303 are fixedly arranged with the crossbeam 104. The plurality of groups of vice beams 304 in the middle of the main beam 303 are each provided with a pushing member 305 arranged along the radial direction of the crossbeam 104. The pushing member 305 is used to finely adjust the position of the crossbeam 104 relative to the vice beam 304. The pushing member 305 applies a pushing force or a pulling force to the crossbeam 104, so that the crossbeam 104 is slightly deformed to correct the precision of the guide rail surface and ensure the high-precision operation of the crossbeam 104. The laser tracker can monitor the relative position and displacement of the piston reference point of the pushing member 305, which is used for precision correction and monitoring. The pushing member 305 is a servo oil cylinder. In view of the cost, the pushing member 305 can be replaced by a screw and a jack structure, and the precision correction needs to be manually performed.

[0081] By setting the torsion beam 300, the posture of the cross beam 104 can be finely adjusted, and the cross beam 104 is kept in the posture, which further improves the precision and rigidity of the gantry frame.

[0082] The torsion beam 300 is a degree correction method. Due to the influence of temperature, load, material and other factors, high-precision machine tools often have the phenomenon of real-time precision floating, which affects the machining quality, so it is necessary to correct the precision of high-precision machine tools.

[0083] Specifically, as shown in Figure 7 , the cross beam 104 is provided with a slide 105, the slide 105 is fixed with a tool holder 106, the tool holder 106 is provided with a slide block 309, and a precision marble angle ruler 308 is aligned with the machine tool reference. Then the micrometer 307 is adsorbed on the slide block 309 of the tool holder 106. The slide block 309 moves up and down, and the reading trend t1 of the micrometer 307 at this time is recorded. Change the position of the slide 105 in the left and right directions of the cross beam 104, and then perform the above operation to record the data t2, t3,..., tn. Thereafter, the precision is corrected by the torsion beam 300, which needs to meet the conditions: ① the reading trend t1-tn is consistent; ② the straightness of the slide 105 moving on the cross beam 104 meets the precision requirement. After meeting the above conditions, the precision correction of the cross beam 104 is completed.

[0084] As shown in Figure 8 , it is a design drawing of the unloading device 400. The part of the cross beam 104 where the tool holder 106 is arranged is heavier than other parts of the cross beam 104, and is affected by gravity, which will affect the precision of the tool holder 106. Therefore, the unloading device 400 is arranged to transfer the load of the tool holder 106 on the cross beam 104 to the column close to the tool holder 106, so the unloading device 400 is arranged on the column close to the tool holder 106. The unloading device 400 is installed on the lead screw 110 and bears the load through the lead screw 110. The unloading device 400 includes an unloading nut 401 and an unloading telescopic piece 402. The unloading nut 401 is sleeved on the lead screw 110. The unloading telescopic piece 402 includes a fourth base 403 and a fourth telescopic piece 404. The fourth base 403 is fixed on the unloading nut 401, and the fourth telescopic piece 404 is fixed with the cross beam 104.

[0085] Specifically, the unloading telescopic member 402 is a hydraulic telescopic member, the unloading telescopic member 402 comprises an unloading oil cylinder and an unloading piston, the fourth base 403 is the unloading oil cylinder, the fourth telescopic member 404 is the unloading piston, and the unloading piston is connected with the cross beam 104. The working principle of the unloading device 400 is that the load on the part of the cross beam 104 close to the tool holder 106 is transmitted to the lead screw 110 through the unloading oil cylinder and the unloading piston. And the hydraulic oil pressure in the unloading oil cylinder changes according to the position of the slide 105 on the cross beam 104, always unloading the increased load on the cross beam 104 close to the tool holder 106, ensuring that the load of the cross beam 104 on the positioning block 202 close to the tool holder 106 is constant, reducing the deformation amount of the positioning block 202, and increasing the stability of the precision of the cross beam 104.

[0086] By setting the unloading device 400, the changed load for balancing the left and right movement of the tool holder 106 is balanced to reduce uneven deformation, and the precision of the gantry frame is further improved.

[0087] As shown in Figure 9 , it is a schematic diagram of the reverse deformation curve of the cross beam 104. In order to limit the movement direction of the tool holder 106, a guide rail surface is arranged on the cross beam 104, and the tool holder 106 moves along the guide rail surface. In order to ensure the working precision of the cross beam 104, the cross beam 104 is given a proper reverse deformation amount in the up-down and front-back directions during machining by using finite element simulation analysis and related experience data.

[0088] As shown in Figure 10 , it is a schematic diagram of the reverse deformation curve of the column. In order to ensure the working precision of the first column 101 and the second column 102, the first column 101 and the second column 102 are given a proper reverse deformation amount in the front-back direction during machining by using finite element simulation analysis and related experience data.

[0089] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A high-precision staging and positioning gantry frame, characterized by, The utility model relates to a kind of two-axis gantry machining center, including: Two columns, two The column is vertically extended and arranged, and the two columns are horizontally spaced apart, and each of the column is provided with a lifting mechanism; Crossbeam, the two ends of the crossbeam are driven to lift along the vertical direction by two lifting mechanisms respectively; Two hierarchical positioning devices, two The hierarchical positioning device is used for positioning the two ends of the crossbeam respectively, and the hierarchical positioning device includes positioning strip, positioning block and telescopic drive, the positioning strip is fixed on the column and is arranged along the vertical direction, a plurality of The positioning block is arranged along the vertical direction and is sequentially fixed on the positioning strip at a certain distance, and the telescopic drive includes first base and first mobile end, the first base is fixed on the end of the crossbeam, and the first mobile end can advance or retreat relative to the positioning block, so that the first mobile end is abutted on the positioning block or away from the positioning block; The hierarchical positioning device further includes connecting sleeve and nut seat, the connecting sleeve includes first sleeve and second sleeve fixedly connected from bottom to top, the first sleeve is sleeved on the screw nut and is fixedly connected with the screw nut, the second sleeve is sleeved on the lead screw and is slidably connected with the lead screw, the nut seat is sleeved on the second sleeve and is slidably connected with the second sleeve, and the nut seat is fixedly connected with the end of the crossbeam; Wherein, the top of the first sleeve is provided with a resting surface, and the resting surface is used for resting the nut seat; It further includes top-tight telescopic element and clamping telescopic element, the crossbeam is provided with a guide surface with machining precision higher than a preset precision threshold, the top-tight telescopic element includes second base and second mobile end, the second base is fixed on the crossbeam, and the second mobile end is abutted on one The column is provided with a surface that can be closely combined with the guide surface, and a plurality of The clamping telescopic element is arranged on the two sides of the two columns, and the clamping telescopic element includes third base and third mobile end, the third base is fixed on the crossbeam, and the third mobile end is abutted on the column; The crossbeam is further provided with a torsion beam, the torsion beam includes main beam and vice beam, the axial direction of the main beam is parallel to the axial direction of the crossbeam, and the vice beam is fixedly arranged with the main beam, a plurality of The vice beam is sequentially arranged at a certain distance along the axial direction of the main beam, each group of the vice beam includes two vice beams symmetrically arranged relative to the main beam, the main beam is arranged at a certain distance from the crossbeam, and the two groups of the vice beam at both ends of the main beam are fixedly arranged with the crossbeam, and a plurality of The vice beam in the middle of the main beam and the crossbeam are both provided with a pushing element arranged along the radial direction of the crossbeam, and the pushing element is used for fine adjustment of the position of the crossbeam relative to the vice beam;Pushing element applies pushing force or pulling force to crossbeam, so that it produces slight deformation to correct the precision of guide surface, ensure the high-precision operation of crossbeam;Laser tracker can monitor the relative position and displacement of the piston reference point of pushing element, for precision correction and monitoring. When the cross beam is finished with the grading movement and reaches the initial state, the telescopic part is tightened and the telescopic part is clamped to clamp the two columns, the connecting sleeve and the nut seat are separated, and the cross beam is completely placed on the positioning block; The unloading device includes an unloading nut and an unloading telescopic part, the unloading nut is sleeved on the lead screw, the unloading telescopic part includes a fourth base and a fourth telescopic part, the fourth base is fixed on the unloading nut, and the fourth telescopic part is fixed with the cross beam; The load on the part of the cross beam close to the tool holder is transmitted to the lead screw through the unloading oil cylinder and the unloading piston, and the hydraulic oil pressure in the unloading oil cylinder changes according to the position of the slide on the cross beam, so that the increased load on the part of the cross beam close to the tool holder is always unloaded, the load applied by the cross beam to the positioning block on the column close to the tool holder is constant, the deformation of the positioning block is reduced, and the stability of the cross beam precision is increased.

2. The high-precision grading positioning gantry frame according to claim 1, characterized in that: The connecting beam is further provided with a double-output-shaft motor, the double-output-shaft motor drives the two lifting mechanisms to move synchronously through two transmission shafts.

3. The high-precision grading positioning gantry frame according to claim 1, characterized in that: The lifting mechanism includes a rotating drive, a lead screw and a lead screw nut, the rotating drive is fixed on the column, the lead screw is fixedly connected with the output shaft of the rotating drive, and the lead screw nut is sleeved on the lead screw and fixed with the end of the cross beam.

4. The high-precision grading positioning gantry frame according to claim 1, characterized in that: The lead screw nut further includes a safety nut, the safety nut is fixedly connected with the connecting sleeve and sleeved on the lead screw, and the safety nut is arranged below the lead screw nut.

5. The high-precision grading positioning gantry frame according to claim 1, characterized in that: The grading positioning device further includes an identification sensor and a plurality of coding blocks, the coding blocks are arranged on the positioning strip at intervals in the vertical direction, each coding block is arranged on one side of the positioning block, and the identification sensor is fixed on the first base to identify the coding blocks.

6. A machine tool, characterized by The high-precision grading positioning gantry frame according to any one of claims 1-5.

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