Measurement compensation device

Abstract

According to the measurement compensation device, a mechanical compensation mode is adopted, the measurement angle is compensated in a self-adaptive mode according to different postures of the measured workpiece, the sensor and the measured workpiece are kept relatively perpendicular all the time, and the measurement requirement is met. The measurement compensation device comprises a supporting bridge frame, and a measurement contact block, a floating head assembly and a measurement unit which are arranged on the supporting bridge frame, the measuring contact block is used for being in direct contact with a measured workpiece; the floating head assembly is used for self-adapting to the posture of the measured workpiece and ensuring that the measuring contact block is always clung to the measured workpiece; the measuring unit is used for measuring the to-be-measured position of the to-be-measured workpiece to obtain measurement data.

Description

Technical Field

[0001] The invention relates to a measuring device, in particular to a measuring compensation device, and belongs to the technical field of measuring instruments. Background Art

[0002] When measuring, industrial robots cannot solve possible operational errors by relying solely on high-precision sensors. For example, the workpiece is often not placed perpendicular to the horizontal plane. When the workpiece is not placed perpendicular to the horizontal plane, the sensor will not be able to measure the error. Figure 1 There will be an error in the straight line distance between point D, that is, a point on the spindle end face of the workpiece to the horizontal plane. If the sensor measures the actual distance deviation of the straight line vertically by a, the measured deviation value will be Figure 1 In the figure, c represents the length of the straight line. It is obvious that there is a certain gap between the two measured values.

[0003] For measurements with strict precision requirements, even a very small error can have a great impact on the measurement accuracy of the assembly. To address this problem, the measurement theory and method based on the robot end precision is currently commonly used. Most of them propose to fit an ideal plane on the workpiece first, that is, through a certain algorithm or method, find an ideal plane that can represent the workpiece, and then calculate the distance from the point to the plane based on the ideal plane to obtain the deviation calculation method. Although this method can improve the measurement accuracy, it requires the selection of a large amount of data and complex calculation and analysis of the data, which often places high requirements on the measurement software. Summary of the invention

[0004] In view of this, the present invention proposes a measurement compensation device, which adopts a mechanical compensation method to adaptively compensate the measurement angle according to different postures of the workpiece being measured, and always keeps the sensor and the workpiece being measured relatively perpendicular to each other to meet the measurement requirements.

[0005] The technical solution of the present invention is: a measurement compensation device, comprising: a support bridge and a measurement contact block, a floating head assembly and a measurement unit installed on the support bridge;

[0006] The measuring contact block is used to directly contact the workpiece to be measured;

[0007] The floating head assembly is used to adapt to the posture of the workpiece being measured to ensure that the measuring contact block is always in close contact with the workpiece being measured;

[0008] The measuring unit is used to measure the position to be measured of the workpiece to obtain measurement data.

[0009] As a preferred embodiment of the present invention: the floating head assembly comprises: a guide column fixing plate, an elastic member, a guide sleeve fixing plate, a spherical roller bearing and a connecting flange;

[0010] One end of the guide sleeve fixing plate is connected to the support bridge, and the other end is connected to the guide column fixing plate through a plurality of elastic members evenly spaced along the circumference;

[0011] A shaft sleeve is extended from the other end of the guide column fixing plate; the connecting flange is coaxially sleeved on the outside of the shaft sleeve of the guide column fixing plate through a spherical roller bearing.

[0012] As a preferred embodiment of the present invention: the elastic member is a rectangular spring, a guide column is coaxially arranged inside the elastic member, one end of the guide column is connected to the guide column fixing plate, and the other end is slidably matched with a guide sleeve arranged on the guide sleeve fixing plate.

[0013] As a preferred embodiment of the present invention: a Z-axis angle compensation upper plate is provided on the outer circumferential surface of the connecting flange, and a Z-axis angle compensation lower plate is provided on the guide column fixing plate;

[0014] The limiting boss at the end of the Z-axis angle compensation upper plate can be inserted into the limiting groove on the Z-axis angle compensation plate B to achieve locking between the guide column fixing plate and the connecting flange.

[0015] As a preferred embodiment of the present invention, a plurality of Z-axis angle compensation plates B are provided on the guide column fixing plate at intervals along the circumferential direction.

[0016] As a preferred embodiment of the present invention: the support bridge comprises: a central sleeve and more than three support claws evenly spaced and distributed along the circumference of the central sleeve; each end of the support claw is detachably connected to a measuring contact block.

[0017] As a preferred embodiment of the present invention: the measuring unit sensor and the sensor fixing assembly;

[0018] The sensor is mounted on the central sleeve through the sensor fixing assembly, and the measuring end of the sensor is located at an eccentric position of an end surface of the central sleeve facing the measured element.

[0019] As a preferred embodiment of the present invention, two sensors are installed on the central sleeve.

[0020] As a preferred embodiment of the present invention: an anti-collision block is sleeved on the outside of the sensor measuring end, and the anti-collision block is connected to the central sleeve.

[0021] Beneficial effects:

[0022] (1) The present invention is provided with a floating head assembly, which can adaptively compensate the measurement angle according to the different postures of the workpiece to be measured, ensuring that the measuring unit and the reference plane of the workpiece to be measured are always perpendicular to meet the measurement requirements.

[0023] (2) In the present invention, a measuring contact block is provided at the end of the supporting claw. Since the measuring contact block is detachable and replaceable, a matching measuring contact block can be used according to the shape of the workpiece to be measured, thereby expanding the range of workpieces to which the device is applicable.

[0024] (3) In the present invention, a Z-axis angle compensation plate A is provided on the circumference of the connecting flange, and a Z-axis angle compensation plate B is provided on the guide column fixing plate. The two can be locked with each other to prevent the entire device from sagging due to force, thereby ensuring measurement stability.

[0025] (4) In the present invention, by arranging a plurality of Z-axis angle compensation plates B along the circumferential direction on the guide column fixing plate, it is possible to further improve the measurement accuracy by performing multiple measurements at different positions.

[0026] (5) In the present invention, an anti-collision block is provided to protect the sensor, thereby improving the safety of the device during the measurement process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of measurement when the workpiece mentioned in the background technology is not placed perpendicular to the horizontal plane;

[0028] Figure 2 This is a schematic diagram of the back measurement compensation principle;

[0029] Figure 3 It is a schematic diagram of the overall structure of the measurement compensation device of the present invention;

[0030] Figure 4 A half-section diagram of the measurement compensation device of the present invention;

[0031] Figure 5 It is a schematic diagram of the measurement compensation device of the present invention when in use;

[0032] Figure 6 The schematic diagram of the structure of the supporting bridge is shown in FIG.

[0033] Figure 7 It is a three-dimensional structural schematic diagram of the floating head assembly;

[0034] Figure 8 is a cross-sectional view of a floating head assembly;

[0035] Fig. 9 It is a schematic diagram of the structure of the measuring contact block;

[0036] Fig.10 It is a schematic diagram of the structure of the anti-collision block;

[0037] Fig.11 It is a structural schematic diagram of the sensor fixing plate;

[0038] Fig.12 This is a structural diagram of the Z-axis angle compensation plate B;

[0039] Fig.13 This is a structural diagram of the Z-axis angle compensation plate A;

[0040] Fig.14 A cross-sectional view of a guide sleeve fixing plate;

[0041] Fig.15 It is the front view of the guide column fixing plate;

[0042] Fig.16 It is a cross-sectional view of the guide column fixing plate;

[0043] Fig.17 It is a cross-sectional view of the connecting flange;

[0044] Fig.18 This is the front view of the bearing pressure ring;

[0045] Fig.19 This is the left view of the bearing pressure ring;

[0046] Among them, 1-support bridge, 2-measurement contact block, 3-floating head assembly, 4-Z-axis angle compensation plate A, 5-sensor fixing assembly, 6-track base, 7-measured workpiece, 8-guide sleeve fixing plate, 9-guide column fixing plate, 10-connecting flange, 11-center sleeve, 12-support claw, 13-elastic part, 14-spherical roller bearing, 15-bearing pressure ring, 41-Z-axis angle compensation plate B, 51-sensor fixing plate, 52-mounting block, 53-anti-collision block, 54-sensor, 55-limit bolt. DETAILED DESCRIPTION

[0047] In order to better understand the present invention, the technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0048] In order to solve the problem that the measured deviation value is significantly different from the actual deviation when the workpiece cannot be placed horizontally during the robot measurement process, the present embodiment provides a measurement compensation device that can adaptively compensate the measurement angle according to the different postures of the workpiece being measured, always keep the sensor and the workpiece being measured relatively vertical, and meet the measurement requirements.

[0049] like Figure 3 and Figure 4 As shown, the measurement compensation device includes: a supporting bridge 1, a measurement contact block 2, a floating head assembly 3 and a measurement unit.

[0050] The support bridge 1 is the skeleton of the measuring device. The measuring contact block 2 is installed on the support bridge 1 and is used to directly contact the workpiece 7 to be measured (specifically, to directly contact the reference surface selected on the workpiece 7 to be measured); to adapt to different workpiece products to be measured, only the measuring contact block 2 needs to be replaced; the floating head assembly 3 is installed on the support bridge 1 and can adapt to the angle of the workpiece to be measured to ensure that the measuring contact block 2 is always firmly attached to the workpiece to be measured; the measuring unit is a sensor installed on the support bridge 1 through the sensor fixing assembly 5, which is used to measure the position to be measured of the workpiece 7 to obtain measurement data. When in use, the device can be suspended on a mobile guide rail base or on a test robot to measure the size of the workpiece.

[0051] For the convenience of description, the normal direction of the reference plane of the workpiece 7 to be measured is defined as the Z direction, the horizontal direction within the reference plane is defined as the X direction, and the vertical direction is defined as the Y direction.

[0052] like Figure 5 As shown, the floating head assembly 3 of the device is connected to the track base 6 or the robot arm through the connecting flange 10, and the side where the supporting bridge 1 is located faces the workpiece 7 to be measured; the measuring contact block 2 on the supporting bridge 1 is vertically pressed on the workpiece 7 to be measured, and the device is used to measure the distance of the position to be measured on the workpiece 7 relative to the reference plane in the Z-axis direction.

[0053] As an independent module, the measurement compensation device can be installed on test equipment other than the track base 6 or the robot arm for use, only by differentially designing the interface of the connecting flange 10 in the floating head assembly 3.

[0054] Specific:

[0055] like Figure 6 As shown, the support bridge 1 includes: a central sleeve 11 located in the center and more than three support claws 12 evenly spaced along the circumference of the central sleeve 11. As an example, the support bridge 1 is a three-claw bridge, that is, three support claws 12 are evenly spaced along the circumference. The material of the support bridge 1 is 6061 aluminum alloy to reduce the overall weight; and the three-claw bridge is a universal tooling frame, covering the measured size range of six hydraulic comprehensive transmission products. The three support claws 12 are welded to the central sleeve 11.

[0056] Each supporting claw 12 is connected to a bottom portion thereof. Fig. 9 The measuring contact block 2 shown is detachably connected to the support claw 12 (e.g., connected by screws). Before installing the measuring contact block 2, both sides thereof are fully ground to ensure that it fits tightly with the workpiece 7 to be measured and the support claw 12. Since the measuring contact block 2 can be installed and removed from the support claw 12, the measuring contact block 2 can be quickly replaced with an appropriate one according to the structural differences of different workpieces 7 to be measured, that is, the measuring contact block 2 is a special part.

[0057] A floating head assembly 3 is connected to the end of the support bridge 1 away from the measuring contact block 2. Its function is to adapt to the shape of the reference surface on the measured workpiece 7 when the measuring contact block 2 at the end of each supporting claw 12 is in full contact with the reference surface of the measured workpiece 7, so that the measuring unit and the reference surface of the measured workpiece 7 are always kept perpendicular.

[0058] like Figure 7-Figure 19 As shown, the floating head assembly 3 includes: a guide column fixing plate 9, an elastic member 13, a guide sleeve fixing plate 8, a spherical roller bearing 14 and a connecting flange 10. One end of the guide sleeve fixing plate 8 is connected to the support bridge 1, and the other end is connected to the guide column fixing plate 9 through a plurality of elastic members 13 evenly spaced along the circumferential direction. A sleeve extends from the other end of the guide column fixing plate 9; the connecting flange 10 is coaxially sleeved on the outside of the sleeve of the guide column fixing plate 9 through the spherical roller bearing 14 (the connecting flange 10 is connected to the outer ring of the spherical roller bearing 14 through the bearing pressure ring 15 and the limit bolt 55, and the bearing pressure ring 15 is used for the axial limit of the spherical roller bearing 14), and the guide column fixing plate 9 can rotate relative to the connecting flange 10 to adjust the measurement position (the rotation of the guide column fixing plate 9 causes the support bridge 1 and the measuring unit on the support bridge 1 to rotate, and the measuring unit is located at the eccentric position of the support bridge 1); the connecting flange 10 is also the connection interface between the measurement compensation device and the track base 6 or the machine arm; that is, the connecting flange 10 is both the support seat of the spherical roller bearing 14 and the connection interface between the entire measuring device and the outside. The spherical roller bearing 14 ensures the support and adjustment of the angle of the entire measuring device after the elastic member 13 is subjected to force. When selecting, the aligning angle of the spherical roller bearing 14 is greater than the placement deviation angle of the workpiece to be measured.

[0059] As an example, there are three elastic members 13 , which are distributed at intervals of 120° to ensure uniform force.

[0060] As an example, a plurality of limit bolts 55 are evenly spaced along the circumference of the bearing pressure ring 15, and are fixedly connected to the outer ring of the spherical roller bearing 14 through the bearing pressure ring 15. The limit bolts 55 can limit the maximum deviation angle of the rotation of the spherical roller bearing 14, and protect the spherical roller bearing 14. Nuts, spacers and adjustment pads are sleeved on the bolt heads of the limit bolts 55 to increase the fixing effect of the limit bolts 55.

[0061] As an example, the elastic member 13 adopts a rectangular spring; a guide column is coaxially arranged inside the rectangular spring along the axial direction thereof, one end of the guide column is connected to the guide column fixing plate 9, and the other end is slidably matched with the guide sleeve arranged on the guide sleeve fixing plate 8. Specifically: one end of the guide column extends from one side of the rectangular spring and passes through the guide sleeve fixing plate 8; an oil-free bushing is sleeved on the outer side of the extended end as a guide sleeve, which is used to reduce friction and wear on the guide column and improve the performance and durability of the rectangular spring; the other end of the guide column is connected to the guide column fixing plate 9; the guide column can be axially extended and retracted relative to the guide sleeve.

[0062] The diameter of the rectangular spring is selected according to the diameter of the guide column and is larger than the diameter of the guide column. The compression strength of the rectangular spring should be as small as possible while meeting the thrust pressure to ensure that the support bridge 1 and the workpiece 7 to be measured can be tightly compacted while floating flexibly.

[0063] The connecting flange 10 is provided with Fig.13 The Z-axis angle compensation plate A4 shown in the figure is provided on the guide column fixing plate 9 as follows Fig.14 The Z-axis angle compensation plate B41 and the Z-axis angle compensation plate A4 are arranged on the outer circumference of the connecting flange 10 and can slide relative to the connecting flange 10 so that the limiting boss at its end is inserted into the limiting groove on the Z-axis angle compensation plate B41, thereby realizing the limiting connection between the guide column fixing plate 9 and the connecting flange 10, and then realizing the rotation limiting of the guide column fixing plate 9, i.e. locking. The Z-axis angle compensation plate A4 and the Z-axis angle compensation plate B41 with limiting are used to prevent the measuring device from lowering its head along the Z-axis at the end of the robot, so that the measuring compensation device can stably obtain the measuring data and improve the measuring stability of the device.

[0064] As an example, a plurality of Z-axis angle compensation plates B41 are provided at intervals along the circumferential direction on the guide column fixing plate 9. After the guide column fixing plate 9 is rotated, the Z-axis angle compensation plates B41 at different positions are locked with the Z-axis angle compensation plate A4 to achieve stable measurement of data at different positions. That is, the amount of data that can be measured multiple times by the measurement compensation device depends on how many sets of locking positions there are between the guide column fixing plate 9 and the Z-axis angle compensation plate 4 during the rotation of the floating head assembly 3. Different locking points can be designed for the guide column fixing plate 9 to meet different usage conditions.

[0065] The measuring unit is mounted on the central sleeve 11 of the supporting bridge 1. The measuring unit includes: a sensor 54 and a sensor fixing assembly. The sensor 54 can be a displacement sensor or an infrared sensor. The measuring end of the sensor 54 is located at an eccentric position (i.e., a position deviating from the axis of the central sleeve 11) of the end face of the central sleeve 11 facing the measured element 7. The electrical connection wire of the sensor 54 is placed in the central sleeve 11.

[0066] The sensor fixing assembly 5 includes: a fixing plate 51 and a mounting block 52, wherein the fixing plate 51 is arranged on the end face of the center sleeve 11 facing the workpiece 7 to be measured, the mounting block 52 is located in the center sleeve 11 and connected to the fixing plate 51, and the sensor 54 is installed on the mounting block 52; the measuring end of the sensor 54 extends from the fixing plate 51.

[0067] As an example, there are two sensors 54, which are located at different positions on the fixed plate 51; one sensor 54 can be used to measure the Z-direction dimension of the reference plane of the workpiece 7 to be measured, and the other sensor 54 is used to measure the Z-direction dimension of the set point to be measured on the workpiece 7 to be measured, so that the Z-direction dimension of the set point to be measured on the workpiece 7 to be measured relative to its reference plane can be obtained in one measurement.

[0068] The measuring device can also be used to measure the height of the step surface or the depth of the hole on the workpiece 7; when measuring the height of the step surface, it is only necessary to measure the distances of the two surfaces used to form the step relative to the reference surface respectively, and then calculate the difference.

[0069] The sensor fixing assembly 5 further includes: an anti-collision block 53; the anti-collision block 53 is a cylindrical structure with two ends open, and the anti-collision block 53 is sleeved outside the measuring end of the sensor 54, and the anti-collision block 53 is fixedly connected to the fixing plate 51, that is, the measuring end of the sensor 54 passes through the anti-collision block 53. In this example, the sensor 54 is a contact displacement sensor, and the contact displacement sensor has a retractable measuring end, and its measuring end can be extended or retracted into the anti-collision block 53 to protect the sensor 54.

[0070] The fixing plate 51 , the mounting block 52 and the anti-collision block 53 of the sensor fixing assembly 5 can meet the installation requirements of the displacement sensor, the infrared sensor or other sensors through the differentiated design of the shapes.

[0071] When the measurement compensation device is used to measure the size of the workpiece:

[0072] The measuring and compensating device is connected to the track base 6 or the robot arm through the connecting flange 10; the measuring and compensating device is driven to move closer to the workpiece 7 to be measured by moving the track base 6 or the robot arm; the measuring contact blocks 2 at the front end of the supporting bridge 1 can all contact with the reference surface of the workpiece 7 to be measured; the measuring contact blocks 2 gradually press the reference surface of the workpiece 7 to be measured, and in the process of pressing, the elastic member 13 on the floating head assembly 3 is tilted by force, and the angular deviation of the workpiece to be measured in the Z direction is automatically compensated (in this process, the displacement sensor installed on the supporting bridge 1 through the sensor fixing assembly 5 is tilted together with the floating head assembly 3 with the workpiece to be measured 7, and the measurement angle is adaptively compensated); during measurement, the Z-axis angle compensation plate A4 and the Z-axis angle compensation plate B41 are locked together to achieve mechanical limit, the workpiece to be measured 7 is measured, and the data is transmitted to the data processing module through the test line.

[0073] When the measuring position needs to be adjusted, the Z-axis angle compensation plate A4 and the Z-axis angle compensation plate B41 are disconnected, the lock is released, and the floating head assembly 3 is rotated to perform multi-position measurement (measure different positions on the surface to be measured, and then calculate the average to improve the measurement accuracy).

[0074] When switching products and the shape of the workpiece being measured changes, it is only necessary to remove the measuring contact block 2 before measuring and replace it with a matching measuring contact block 2.

[0075] The angle that the measuring compensation device can compensate depends on the pressing force of the elastic member 13 in the floating head assembly 3 and the adjustment angle of the spherical roller bearing 12; according to different measurement requirements, only the elastic member 13 and the spherical roller bearing 12 need to be selected to meet different usage conditions.

[0076] The measuring and compensation device is positioned with the mounting surface of the workpiece to be measured through three claws, and can be installed on the test equipment in different postures as needed, so as to realize the angle deviation compensation in any direction of X\Y\Z axis.

[0077] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A measurement compensation device, characterized in that: include: A supporting bridge (1), and a measuring contact block (2), a floating head assembly (3), and a measuring unit installed on the supporting bridge (1); The measuring contact block (2) is used to directly contact the workpiece (7) to be measured; The floating head assembly (3) is used to adapt to the posture of the workpiece (7) being measured, so as to ensure that the measuring contact block (2) is always in close contact with the workpiece (7) being measured; The measuring unit is used to measure the position to be measured of the workpiece (7) to obtain measurement data.

2. The measurement compensation device according to claim 1, characterized in that: The floating head assembly (3) comprises: a guide column fixing plate (9), an elastic member (13), a guide sleeve fixing plate (8), a spherical roller bearing (14) and a connecting flange (10); One end of the guide sleeve fixing plate (8) is connected to the support bridge (1), and the other end is connected to the guide column fixing plate (9) via a plurality of elastic members (13) evenly spaced along the circumference; A shaft sleeve extends from the other end of the guide column fixing plate (9); the connecting flange (10) is coaxially sleeved on the outside of the shaft sleeve of the guide column fixing plate (9) via a spherical roller bearing (14).

3. The measurement compensation device according to claim 2, characterized in that: The elastic member (13) is a rectangular spring, a guide column is coaxially arranged inside the elastic member, one end of the guide column is connected to the guide column fixing plate (9), and the other end is slidably matched with a guide sleeve arranged on the guide sleeve fixing plate (8).

4. The measurement compensation device according to claim 2, characterized in that: A Z-axis angle compensation upper plate (4) is provided on the outer circumferential surface of the connecting flange (10), and a Z-axis angle compensation lower plate (41) is provided on the guide column fixing plate (9); The limiting boss at the end of the Z-axis angle compensation upper plate (4) can be inserted into the limiting groove on the Z-axis angle compensation plate B (41) to achieve locking between the guide column fixing plate (9) and the connecting flange (10).

5. The measurement compensation device according to claim 4, characterized in that: A plurality of Z-axis angle compensation plates B (41) are arranged at intervals along the circumferential direction on the guide column fixing plate (9).

6. The measurement compensation device according to any one of claims 1 to 5, characterized in that: The support bridge (1) comprises: a central sleeve (11) and more than three support claws (12) evenly spaced and distributed along the circumference of the central sleeve (11); the end of each support claw (12) is detachably connected to a measurement contact block (2).

7. The measurement compensation device according to claim 6, characterized in that: The measuring unit sensor (54) and the sensor fixing assembly; The sensor (54) is mounted on the central sleeve (11) via the sensor fixing assembly, and the measuring end of the sensor (54) is located at an eccentric position of an end surface of the central sleeve (11) facing the measured element (7).

8. The measurement compensation device according to claim 7, characterized in that: Two sensors (54) are mounted on the central sleeve (11).

9. The measurement compensation device according to claim 6 or 7, characterized in that: An anti-collision block (53) is sleeved on the outside of the measuring end of the sensor (54), and the anti-collision block (53) is connected to the central sleeve (11).

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