Large-span full-size three-coordinate measuring machine

Abstract

The invention provides a large-span full-size three-coordinate measuring machine, which particularly relates to the technical field of measurement, and comprises a supporting table, a mechanical device, a measuring head structure and a host, and the mechanical device and the measuring head structure are arranged on the supporting table. A position adjusting structure used for supporting to-be-tested parts of different sizes is arranged in the supporting table, the to-be-tested parts are in multi-point contact with the position adjusting structure, and a movable supporting structure is arranged on the mechanical device; the supporting table and the to-be-measured part are separately contacted with the movable supporting structure, and the measuring head structure is separately connected with the movable supporting structure. The large-span full-size three-coordinate measuring machine provided by the invention can perform full-size blind-spot-free measurement on workpieces with complex structures and large sizes, does not need to change the position of a to-be-measured part, is also suitable for measurement of parts with different sizes, and particularly can complete the measurement process of the large-size to-be-measured part.

Description

Technical Field

[0001] The invention belongs to the field of measurement technology, and in particular relates to a large-span full-size three-coordinate measuring machine. Background Art

[0002] The existing three-coordinate measuring instrument refers to an instrument that can measure geometric shapes, lengths, and circular divisions within the space of a hexahedron. It is also called a three-coordinate measuring machine or a three-coordinate measuring bed. The three-coordinate measuring instrument can also be defined as "an instrument with a detector that can move in three directions and can move on three mutually perpendicular guide rails. This detector transmits signals in a contact or non-contact manner. The displacement measurement system of the three axes (such as a grating ruler) calculates the various points (x, y, z) of the workpiece and various functional measurements through a data processor or computer." The measurement functions of the three-coordinate measuring instrument should include dimensional accuracy, positioning accuracy, geometric accuracy, and contour accuracy.

[0003] Simply put, a three-dimensional coordinate measuring machine is a measuring device that has a guide mechanism, a length measuring element, and a digital display device in three mutually perpendicular directions, a workbench that can place workpieces (not necessarily large and giant machines), and a probe that can be moved to the measured point manually or motorizedly. The coordinate value of the measured point is displayed by the reading device and the digital display device. Obviously, this is the simplest and most primitive measuring machine. With this measuring machine, the coordinate value of any point in the measuring volume can be displayed by the reading device and the digital display device. The point sampling and signaling device of the measuring machine is a probe, which is equipped with a grating ruler and a reading head along the three axes of X, Y, and Z. The measurement process is that when the probe contacts the workpiece and sends a point sampling signal, the control system collects the coordinate values ​​of the current three-axis coordinates of the machine tool relative to the origin of the machine tool, and then the computer system processes the data.

[0004] However, the three-dimensional coordinate measuring machine in the prior art has the following technical problems when measuring actual workpieces: (1) Due to the structural characteristics of some complex parts, it is impossible to achieve full-size three-dimensional measurement of the parts on the inspection fixture, and thus it is impossible to improve the data basis for the accuracy of the parts. For example, if part of the component is located in the support and clamping block, this part cannot be measured, resulting in incomplete measured data. If the position of the measured object changes (such as vibration, position change), it may even be necessary to re-measure, resulting in measurement errors. (2) For example, for some types of workpieces, if the short side width of the product is larger than the span of the X-axis moving beam, it cannot be measured. A larger CMM is required to meet the requirements, resulting in increased costs. When the span of the X-axis moving beam is large, measurement errors are easily caused by the rigid deformation of the moving beam. (3) When a three-dimensional coordinate measuring machine is used to measure a workpiece, the workpiece needs to be fixed on a fixed table located on the measuring platform of the three-dimensional coordinate measuring machine. The measuring rod cannot complete the detection of a workpiece with a large height. Therefore, how to measure the full-size and blind-spot-free workpieces with complex structures and large sizes has become the key technical problem to be solved in this solution. Summary of the invention

[0005] The purpose of the present invention is to provide a large-span full-size three-dimensional coordinate measuring machine, which solves the technical problem of how to perform full-size blind-spot measurement on workpieces with complex structures and large sizes. It does not need to change the position of the parts to be measured, and is also suitable for measuring parts of different sizes, especially for completing the measurement process of large-size parts to be measured.

[0006] A large-span full-size three-dimensional coordinate measuring machine, comprising a support platform, a mechanical device and a probe structure arranged on the support platform, and a host computer, wherein a control system and a data processing software system are arranged in the host computer, a position adjustment structure for supporting parts to be measured of different sizes is arranged inside the support platform, the parts to be measured are in multi-point contact with the position adjustment structure, and a mobile support structure is arranged on the mechanical device; The support platform and the part to be measured are separately in contact with the movable support structure respectively, and the probe structure is separately connected to the movable support structure.

[0007] The position adjustment structure includes an iris mechanism fixed inside the support platform and a plurality of lifting support components connected to the iris mechanism; The iris mechanism includes a horizontally arranged support plate, five cam plates arranged in a circular array around the center point of the support plate, a driving shaft connected to an angle end of the cam plate, and a power mechanism connected to the driving shaft. The lifting support assembly is provided at the center of the cam plate and the support plate.

[0008] The outer side surface of the cam plate is an arc surface, the center of the arc surface is located at the center point, and the two ends of the arc surface are respectively provided with a concave arc surface and a convex arc surface, the center of the convex arc surface is set at the center of the drive shaft, and the center of the concave arc surface is set at the center of the drive shaft of another adjacent cam plate; The outer ends of the concave arc surface and the convex arc surface are connected through an arc-shaped notch, and the concave arc surfaces and the convex arc surfaces of any two adjacent cam plates are in separate contact.

[0009] The lifting support assembly includes a vertically arranged limit cylinder, a pressure sensor fixed at the bottom end of the limit cylinder, and a support cylinder positioned above the pressure sensor. The support cylinder is arranged inside the limit cylinder, and a wire connected to the pressure sensor is connected to the main machine.

[0010] The movable support structure includes a movable wheel, a wheel seat hinged to the movable wheel, a connecting column connected to the wheel seat at the bottom end, a threaded column with one end coaxially fixed to the top of the connecting column, and a movable seat connected to the other end of the threaded column. The movable seat is connected to the mechanical device through a second power mechanism, and a balancing structure connection is provided on the movable seat for maintaining the balance of the part to be tested.

[0011] The balancing structure includes a telescopic cylinder horizontally fixed on the movable seat, a horizontal plate fixedly connected to the free end of the telescopic cylinder, a lifting cylinder vertically fixed on the horizontal plate, and a pressure plate fixedly connected to the free end of the lifting cylinder.

[0012] The mechanical device includes a long-span beam, movable legs vertically arranged at both ends of the long-span beam, a driving device movably arranged on the long-span beam, and a power mechanism connected to the movable legs. The driving device is connected to the probe structure.

[0013] The probe structure comprises an adjustment column and a probe connected to the bottom end of the adjustment column. The top end of the adjustment column is connected to an up-and-down moving mechanism, and the up-and-down moving mechanism is rotatably connected to the driving device.

[0014] It should be noted that the specific size of the larger workpiece described in this solution is not limited. In principle, as long as it exceeds the measurement range of the existing three-dimensional coordinate measuring machine, this solution is applicable.

[0015] The beneficial effects of the present invention are as follows: (1) A position adjustment structure is provided to achieve the following technical effects: First, through the action of multiple lifting support components, multiple support cylinders can achieve multi-point contact with the bottom of the part to be measured, so as to support the part to be measured. According to the measurement position, the support cylinders and the part to be measured are alternately separated, thereby realizing the detection of every part of the part to be measured; Second, an iris mechanism is provided to adjust the support position of the support cylinder, which is suitable for measuring parts of different sizes; Third, a pressure sensor is provided at the bottom end of the supporting cylinder. Through the detection of multiple pressure sensors, it is determined whether the position of the part to be measured changes, thereby ensuring the accuracy of the measurement of the part to be measured; (2) A mobile support structure is provided to achieve the following technical effects: First, for a large-span beam, the moving wheel contacts the upper end surface of the support platform. When the span of the X-axis moving beam is large, it is easy to cause measurement errors due to the rigid deformation of the moving beam. At this time, the moving wheel is supported on the support platform to ensure that the large-span beam does not deform; Secondly, a balancing structure is provided, and the free end of the lifting cylinder is fixedly connected to a pressing plate, which can be pressed down to the upper end of the part to be measured to avoid the position of the part to be measured being affected by the detachment of the multi-point support, thereby ensuring the balance of the part to be measured and avoiding measurement errors; (3) A mechanical device is provided for use in conjunction with the mobile support structure. On the one hand, the connecting column and the probe structure can be disassembled so that the connecting column and the probe structure can be docked, thereby increasing the length of the probe structure and facilitating the measurement of tall parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a partial structural schematic diagram of the three-coordinate measuring machine in the present invention.

[0017] Figure 2 The structure diagram of the position adjustment structure in the present invention is shown in FIG. Figure 1 .

[0018] Figure 3 The structure diagram of the position adjustment structure in the present invention is shown in FIG. Figure 2 .

[0019] Figure 4 It is a schematic diagram of the connection structure of the cam plate in the present invention.

[0020] Figure 5 It is a structural schematic diagram of the cam plate in the present invention.

[0021] Figure 6 It is a schematic diagram of the connection structure between the support plate and the limiting cylinder in the present invention.

[0022] Figure 7 It is a top view of the support platform in the present invention.

[0023] Figure 8 It is a structural schematic diagram of the mobile support structure in the present invention.

[0024] Fig. 9 It is a schematic diagram of the structure of the connecting column in the present invention.

[0025] Among them, the accompanying drawings are marked as: 1. support platform; 2. movable leg; 3. movable wheel; 4. wheel seat; 5. connecting column; 51. threaded column; 52. threaded hole; 6. movable seat; 7. balance structure; 71. telescopic cylinder; 72. horizontal plate; 73. lifting cylinder; 74. pressure plate; 8. driving device; 9. adjusting column; 10. probe structure; 11. arc groove; 12. position adjustment structure; 120. wire one; 121. support plate; 122. cam plate; 1221. arc notch; 1222. wire two; 123. limit cylinder; 124. support cylinder; 127. synchronous belt; 128. drive shaft; 129. synchronous gear; 1291. synchronous motor. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0027] See also Figure 1-Figure 9 A large-span full-size three-dimensional coordinate measuring machine includes a support platform 1, a mechanical device and a probe structure 10 arranged on the support platform 1, and a host computer. The host computer is provided with a control system and a data processing software system. The support platform 1 is provided with a position adjustment structure 12 for supporting parts to be measured of different sizes. The parts to be measured are in multi-point contact with the position adjustment structure 12. A mobile support structure is provided on the mechanical device. The support platform 1 and the part to be measured are separately in contact with the movable support structure, respectively, and the probe structure 10 is separately connected to the movable support structure.

[0028] The position adjustment structure 12 includes an iris mechanism fixed inside the support platform 1 and a plurality of lifting support components connected to the iris mechanism; The iris mechanism includes a horizontally arranged support plate 121, five cam plates 122 arranged in a circular array around the center point of the support plate 121, a driving shaft 128 connected to an angle end of the cam plate 122, and a power mechanism connected to the driving shaft 128. The cam plate 122 and the support plate 121 are both provided with a lifting support assembly in the center.

[0029] The power mechanism 1 includes a synchronous gear 129 coaxially fixed on a driving shaft 128, and a synchronous belt 127 meshingly connected with a plurality of synchronous gears 129, wherein any synchronous gear 129 is connected to a synchronous motor 1291 via a gear belt.

[0030] The outer side surface of the cam plate 122 is an arc surface, the center of the arc surface is located at the center point, and the two ends of the arc surface are respectively provided with a concave arc surface and a convex arc surface, the center of the convex arc surface is set at the center of the drive shaft 128, and the center of the concave arc surface is set at the center of the drive shaft 128 of another adjacent cam plate 122; The outer ends of the concave arc surface and the convex arc surface are connected by an arc-shaped notch 1221 , and the concave arc surface and the convex arc surface of any two adjacent cam plates 122 are in separate contact; wherein the arc-shaped notch 1221 is clamped on the limiting cylinder 123 on the center of the support plate 121 .

[0031] The lifting support assembly includes a vertically arranged limit cylinder 123, a pressure sensor fixed at the bottom end of the limit cylinder 123, and a support cylinder 124 positioned above the pressure sensor. The support cylinder 124 is arranged inside the limit cylinder 123, and the wire connected to the pressure sensor is connected to the main machine.

[0032] The mobile support structure includes a mobile wheel 3, a wheel seat 4 hinged to the mobile wheel 3, a connecting column 5 connected to the wheel seat 4 at the bottom, a threaded column 51 coaxially fixed at one end to the top of the connecting column 5, and a movable seat 6 connected to the other end of the threaded column 51. The movable seat 6 is connected to the mechanical device through a power mechanism 2, and a balancing structure 7 for maintaining the balance of the part to be tested is provided on the movable seat 6.

[0033] Among them, the power mechanism 2 is a conventional mechanical structure, such as a gear rack mechanism, which only needs to play the role of linear power drive and will not be described in detail here.

[0034] A threaded hole 52 is provided at the other end of the connecting column 5 to facilitate connection with the wheel seat 4 .

[0035] The balancing structure 7 includes a telescopic cylinder 71 horizontally fixed on the movable seat 6, a horizontal plate 72 fixedly connected to the free end of the telescopic cylinder 71, a lifting cylinder 73 vertically fixed on the horizontal plate 72, and a pressure plate 74 fixedly connected to the free end of the lifting cylinder 73.

[0036] The mechanical device includes a long-span beam, movable legs 2 vertically arranged at both ends of the long-span beam, a driving device 8 movably arranged on the long-span beam, and a power mechanism connected to the movable legs 2. The driving device 8 is connected to the probe structure 10.

[0037] The power mechanism 3 is a mechanical mechanism originally set on the three-dimensional coordinate measuring machine, which will not be described in detail here; the function of the driving device 8 is to drive the probe structure to reciprocate along the long-span beam in a straight line.

[0038] The probe structure 10 includes an adjustment column 9 and a probe connected to the bottom end of the adjustment column 9 . The top end of the adjustment column 9 is connected to an up-and-down moving mechanism, and the up-and-down moving mechanism is rotatably connected to the driving device 8 .

[0039] The specific structure of the up-down moving mechanism is a conventional mechanical structure, and in principle, as long as the up-down movement is achieved, it will not be described in detail here. The up-down moving mechanism can be rotatably connected to the driving device 8 through a rotating adjustment mechanism, and the rotating adjustment mechanism is a conventional mechanical mechanism, so that the up-down moving mechanism can rotate a certain angle, which will not be described in detail here.

[0040] The specific working process of the present invention is: A position adjustment structure 12 is provided, and through the action of multiple lifting support components, multiple support cylinders 124 are in multi-point contact with the bottom end of the part to be measured, so as to support the part to be measured. According to the measured position, the support cylinders 124 are alternately separated from the part to be measured, so as to detect every part of the part to be measured; Specifically, since the free ends of the plurality of supporting cylinders 124 are in contact with the bottom end of the part to be measured, similar to the principle of multi-point molding, when the probe structure 10 is to detect the bottom end of the part to be measured, the supporting cylinder 124 of the part is temporarily separated from the part to be measured. At this time, since the other parts of the part to be measured are still in a supported state, the whole part to be measured can still maintain balance without position change. In addition, in cooperation with the balancing structure 7, the free end of the lifting cylinder 73 is fixedly connected to the pressing plate 74, which can be pressed down to the upper end of the part to be measured. The position where the pressing plate 74 contacts the part to be measured is diagonally corresponding to the position where the supporting cylinder 124 and the part to be measured are separated, so as to avoid the position of the part to be measured being affected by the separation of multiple support points, thereby ensuring the balance of the part to be measured and avoiding measurement errors. It should be noted that when a certain part of the bottom of the part to be measured is measured and the next part needs to be measured, the measured part contacts the support cylinder 124 at that position (that is, the free end of the support cylinder 124 at that position rises and contacts and supports the part to be measured), and then the pressing plate 74 is temporarily separated from the top of the part to be measured; then the probe structure 10 moves to the next part to be measured, and the support cylinder 124 of the next part to be measured moves down and separates from the part to be measured, and then the pressing plate 74 contacts and lightly presses the top of the part to be measured again, and contacts and supports the part to be measured. The same as described above (i.e., ensuring that the position where the pressing plate 74 contacts the part to be measured is diagonally corresponding to the position where the supporting cylinder 124 and the part to be measured are separated), the measurement starts; only when the probe structure 10 measures the position where the part to be measured contacts the supporting cylinder 124, the pressing plate 74 will contact the part to be measured, the supporting cylinder 124 and the bottom end of the part to be measured are in point contact, and when the pressing plate 74 contacts the part to be measured, the large-span beam does not move (the driving device 8 can work), so as to avoid the movement of the pressing plate 74 causing shaking to the position of the part to be measured; Preferably, a movable adjustment structure (such as a cylinder) is provided on the driving device, and the movement direction of the movable adjustment structure is perpendicular to the length direction of the large-span beam. The probe structure 10 is positioned and connected to the movable adjustment structure to facilitate the adjustment of the position of the probe structure 10 when the pressure plate 74 contacts the part to be measured. The specific structure of the movable adjustment structure may also be other conventional mechanical structures, which will not be described in detail here and will not be marked in the drawings.

[0041] In addition, the probe at the bottom of the probe structure 10 can rotate automatically and form an angle of 90 degrees with the adjustment column 9, so the probe can conveniently measure the bottom of the part to be measured. The bottom of the part to be measured is supported by multiple supporting cylinders 124 and placed in the air, so that the probe can be extended to the bottom of the part to be measured for measurement. The working principle of the probe belongs to the existing technology and will not be described in detail here.

[0042] An iris mechanism is provided to adjust the support position of the support cylinder 124, which is suitable for measuring parts of different sizes, that is, through the rotation of the synchronous motor 1291, the rotation of the multiple cam plates 122 is driven, and then the limiting cylinders 123 are driven to move in the arc groove 11, and then the coverage area of ​​the multiple limiting cylinders 123 is adjusted, which is suitable for parts of different sizes; Finally, a pressure sensor is provided at the bottom end of the supporting cylinder 124. Through the detection of multiple pressure sensors, it is determined whether the position of the part to be measured changes, thereby ensuring the accuracy of the measurement of the part to be measured. The pressure sensor is connected to the wires (divided into wire 1 120 and wire 2 1222 ), the wires are led out from the bottom of the corresponding cam plate 122 or the support plate 121 , and connected to the host, which will not be described in detail here.

[0043] A mobile support structure is provided. For a large-span beam, the mobile wheel 3 contacts the upper end surface of the support platform 1. When the span of the X-axis mobile beam is large, it is easy to cause measurement errors due to the rigid deformation of the mobile beam. At this time, the mobile wheel 3 is supported on the support platform 1 to ensure that the large-span beam is not deformed. According to the position of the mechanical device and the actual situation of the movement, the mobile wheel 3 moves on the support platform 1 under the driving action of the movable seat 6, maintaining the support effect on the large-span beam; A mechanical device is provided for use in conjunction with the mobile support structure. On the one hand, the connecting column 5 and the probe structure 10 can be disassembled so that the connecting column 5 and the probe structure 10 can be docked, thereby increasing the length of the probe structure 10. Through the mutual cooperation of the up and down moving mechanism, the rotation adjustment mechanism and the driving device, the probe structure 10 can be rotated upward at an obtuse angle, thereby realizing the measurement of tall parts.

[0044] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A large-span full-size three-dimensional coordinate measuring machine, comprising a support platform (1), a mechanical device and a probe structure (10) arranged on the support platform (1), and a host computer, wherein a control system and a data processing software system are arranged in the host computer, characterized in that: The support platform (1) is provided with a position adjustment structure (12) for supporting parts to be tested of different sizes, the parts to be tested are in multi-point contact with the position adjustment structure (12), and the mechanical device is provided with a movable support structure; The support platform (1) and the part to be measured are separately in contact with the movable support structure respectively, and the probe structure (10) is separately connected to the movable support structure.

2. A large-span full-size three-dimensional coordinate measuring machine according to claim 1, characterized in that: The position adjustment structure (12) comprises an iris mechanism fixed inside the support platform (1), and a plurality of lifting support components connected to the iris mechanism; The iris mechanism comprises a horizontally arranged support plate (121), five cam plates (122) arranged in a circular array around the center point of the support plate (121), a drive shaft (128) connected to an angle end of the cam plate (122), and a power mechanism connected to the drive shaft (128); the lifting support assembly is arranged at the center of the cam plate (122) and the support plate (121).

3. A large-span full-size three-dimensional coordinate measuring machine according to claim 2, characterized in that: The outer side surface of the cam plate (122) is an arc surface, the center of the arc surface is located at the center point of the support plate (121), and the two ends of the arc surface are respectively provided with a concave arc surface and a convex arc surface, the center of the convex arc surface is set at the center of the drive shaft (128), and the center of the concave arc surface is set at the center of the drive shaft (128) of another adjacent cam plate (122); The outer ends of the concave arc surface and the convex arc surface are connected via an arc-shaped notch (1221), and the concave arc surfaces and the convex arc surfaces of any two adjacent cam plates (122) are in separate contact.

4. A large-span full-size three-dimensional coordinate measuring machine according to claim 2, characterized in that: The lifting support assembly comprises a vertically arranged limiting cylinder (123), a pressure sensor fixed at the bottom end of the limiting cylinder (123), and a supporting cylinder (124) positioned above the pressure sensor; the supporting cylinder (124) is arranged inside the limiting cylinder (123), and a wire connected to the pressure sensor is connected to the host.

5. The large-span full-size three-dimensional coordinate measuring machine according to claim 1, characterized in that: The movable support structure comprises a movable wheel (3), a wheel seat (4) hinged to the movable wheel (3), a connecting column (5) whose bottom end is connected to the wheel seat (4), a threaded column (51) whose one end is coaxially fixed to the top of the connecting column (5), and a movable seat (6) connected to the other end of the threaded column (51); the movable seat (6) is connected to the mechanical device via a second power mechanism; a balancing structure (7) for maintaining the balance of the part to be tested is provided on the movable seat (6); and a threaded hole (52) is provided at the other end of the threaded column (51).

6. A large-span full-size three-dimensional coordinate measuring machine according to claim 5, characterized in that: The balancing structure (7) comprises a telescopic cylinder (71) horizontally fixed on the movable seat (6), a horizontal plate (72) fixedly connected to the free end of the telescopic cylinder (71), a lifting cylinder (73) vertically fixed on the horizontal plate (72), and a pressure plate (74) fixedly connected to the free end of the lifting cylinder (73).

7. A large-span full-size three-dimensional coordinate measuring machine according to any one of claims 1 to 6, characterized in that: The mechanical device comprises a long-span beam, movable legs (2) respectively arranged vertically at both ends of the long-span beam, a driving device (8) movably arranged on the long-span beam, and a power mechanism connected to the movable legs (2), wherein the driving device (8) is connected to the probe structure (10).

8. The large-span full-size three-dimensional coordinate measuring machine according to claim 1, characterized in that: The probe structure (10) comprises an adjustment column (9) and a probe connected to the bottom end of the adjustment column (9); the top end of the adjustment column (9) is connected to an up-and-down moving mechanism, and the up-and-down moving mechanism is rotatably connected to the driving device (8).

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