Round hole concentricity rapid inspection device

Abstract

The invention relates to the technical field of workpiece quality inspection, in particular to a circular hole concentricity rapid inspection device. The device comprises a multi-degree-of-freedom clamp, a driving mechanism, a first positioning shaft and a second positioning shaft, the multi-degree-of-freedom clamp is used for clamping a to-be-inspected workpiece, and the to-be-inspected workpiece can flexibly move within a certain range under clamping of the multi-degree-of-freedom clamp; the driving mechanism is used for driving the first positioning shaft and the second positioning shaft to get close to or away from each other; and the first positioning shaft and the second positioning shaft can be inserted and matched in the process of approaching each other, and can be inserted and matched with a first concentric hole and a second concentric hole of a workpiece to be inspected respectively. Compared with a three-coordinate measuring instrument for checking the concentricity of the circular hole, the device provided by the invention has the advantages of low cost, short time consumption, simplicity in operation and the like. The device does not depend on the professional degree of operators during use, and is convenient to popularize and use.

Description

Technical Field

[0001] The invention relates to the technical field of workpiece quality inspection, and in particular to a circular hole concentricity rapid inspection device. Background Art

[0002] For some workpieces, the concentricity of the through holes at both ends often has higher design requirements, such as Figure 1 As shown, the concentricity requirement between the hole on the left end and the hole on the right end of the workpiece is usually between 0.01-0.05. Too large a difference in concentricity will cause additional stress in the workpiece during assembly, making assembly difficult or even impossible. Forced assembly will also affect the stability and life of the entire mechanical system.

[0003] In order to check whether the concentricity of two holes on the workpiece meets the requirements, the existing technology usually uses a three-coordinate measuring machine for inspection. This method of using a three-coordinate measuring machine to check the concentricity requires the workpiece to be inspected to be transported to a special three-coordinate measuring room for inspection, which has the disadvantages of inconvenience, long time and high cost. In addition, since the three-coordinate measuring machine has a certain degree of difficulty in operation, this method relies on the professional level of the operator and is not convenient to use. Summary of the invention

[0004] The purpose of the present invention is to provide a device for quickly testing the concentricity of a circular hole, so as to solve the technical problems of inconvenient testing, long time and high cost in the existing method of testing concentricity.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A circular hole concentricity rapid inspection device comprises a multi-degree-of-freedom fixture, a driving mechanism, a first positioning axis, and a second positioning axis, wherein: The multi-degree-of-freedom fixture is used to clamp the workpiece to be inspected, and the workpiece to be inspected can move flexibly within a certain range under the clamping of the multi-degree-of-freedom fixture; The driving mechanism is used to drive the first positioning shaft and the second positioning shaft to approach each other or move away from each other; The first positioning shaft and the second positioning shaft can be plugged and matched in the process of approaching each other, and can be plugged and matched with the first concentric hole and the second concentric hole of the workpiece to be inspected respectively.

[0006] Furthermore, the driving mechanism includes two driving members, the two driving members are symmetrically arranged and the power output ends of the two driving members are respectively fixed to the first positioning shaft and the second positioning shaft.

[0007] Furthermore, the driving mechanism further comprises two connecting plates, and the two connecting plates are respectively fixed to the power output ends of the two driving members; The first positioning shaft and the second positioning shaft are detachably connected to the two connecting plates respectively.

[0008] Furthermore, the driving member is a gas cylinder or an oil cylinder; The driving mechanism further comprises a piston rod position detection structure, which is arranged on one side of the piston rod of the driving member and can detect the movement speed and position of the piston rod.

[0009] Furthermore, the piston rod position detection structure includes a photoelectric sensor, a rack and a testing rod, wherein the testing rod is arranged in parallel with the piston rod of the driving member and the two move synchronously, the rack is fixed to the circumferential surface of the testing rod, and the testing end of the photoelectric sensor faces the tooth surface of the rack.

[0010] Furthermore, the second positioning shaft is of a hollow structure, and a positioning hole is provided at an end of the second positioning shaft close to the first positioning shaft, and the positioning hole is used for plugging and matching with the first positioning shaft.

[0011] Further, the first positioning shaft comprises a first core shaft portion and a first inspection portion, the first core shaft portion is used for plugging and matching with the second positioning shaft, and the first inspection portion is used for plugging and matching with the first concentric hole; And / or, the second positioning shaft includes a second core shaft portion and a second inspection portion, the second core shaft portion is used for plugging and fitting with the first positioning shaft, and the second inspection portion is used for plugging and fitting with the second concentric hole.

[0012] Furthermore, the peripheries of the first inspection portion and the second inspection portion are both provided with chamfers or rounded corners.

[0013] Further, the multi-degree-of-freedom fixture comprises a mounting cylinder, a bracket and a ball plunger, wherein: The installation tube is a cylindrical structure with openings at both ends; The bracket is connected to the bottom of the mounting tube; The ball head plunger is fixedly connected to the installation tube, and the ball head end of the ball head plunger extends into the installation tube and can abut against the workpiece to be inspected.

[0014] Furthermore, there are multiple ball plungers, which are divided into at least two groups of ball plunger groups distributed in sequence along the axial direction of the mounting tube, and each group of ball plunger groups includes multiple ball plungers distributed in sequence along the radial direction of the mounting tube.

[0015] Beneficial effects of the present invention: The circular hole concentricity rapid inspection device provided by the present invention comprises a multi-degree-of-freedom fixture, a driving mechanism, a first positioning axis, and a second positioning axis, wherein: The multi-degree-of-freedom fixture is used to clamp the workpiece to be inspected, and the workpiece to be inspected can move flexibly within a certain range under the clamping of the multi-degree-of-freedom fixture; The driving mechanism is used to drive the first positioning shaft and the second positioning shaft to approach each other or move away from each other; The first positioning shaft and the second positioning shaft can be plugged and matched in the process of approaching each other, and can be plugged and matched with the first concentric hole and the second concentric hole of the workpiece to be inspected respectively.

[0016] Compared with using a three-coordinate measuring instrument to check the concentricity of a circular hole, the device provided by the present application has the advantages of low cost, short time, simple operation, etc. The device does not rely on the professional level of the operator when in use, and is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a schematic diagram of a workpiece to be inspected; Figure 2 A three-dimensional schematic diagram of a circular hole concentricity rapid inspection device provided by an embodiment of the present invention; Figure 3 A forward schematic diagram of a circular hole concentricity rapid testing device provided by an embodiment of the present invention in an initial state; Figure 4 A forward schematic diagram of a circular hole concentricity rapid testing device provided by an embodiment of the present invention in a testing state; Figure 5 A schematic cross-sectional view of a first positioning axis, a second positioning axis and a workpiece to be inspected in an initial state provided by an embodiment of the present invention; Figure 6 A schematic cross-sectional view of a first positioning axis, a second positioning axis and a workpiece to be inspected in an inspection state provided by an embodiment of the present invention; Figure 7 A schematic top view of a device for quickly testing the concentricity of a circular hole provided in an embodiment of the present invention; Figure 8 A lateral schematic diagram of a multi-degree-of-freedom fixture and a workpiece to be inspected provided in one embodiment of the present invention; Fig. 9 A side schematic diagram of a multi-degree-of-freedom fixture and a workpiece to be inspected provided in another embodiment of the present invention.

[0019] icon: 1-multi-degree-of-freedom fixture; 11-mounting cylinder; 111-notch; 12-bracket; 13-ball plunger; 14-sliding rod; 15-compression spring; 2-driving mechanism; 21-driving member; 22-connecting plate; 23-testing rod; 24-photoelectric sensor; 25-rack; 3-first positioning shaft; 31-first core shaft portion; 32-first inspection portion; 4-second positioning shaft; 41-second mandrel portion; 411-positioning hole; 42-second inspection portion; 5-Working platform; 100 - workpiece to be inspected; 101 - first concentric hole; 102 - second concentric hole. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0022] It should be noted that in the description of the present invention, the terms "connection" and "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or connected through an intermediate medium; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The embodiment of the present invention provides a device for quickly testing the concentricity of a circular hole, referring to Figures 1 to 4 The circular hole concentricity rapid inspection device comprises a multi-degree-of-freedom fixture 1, a driving mechanism 2, a first positioning axis 3 and a second positioning axis 4, wherein: The multi-degree-of-freedom fixture 1 is used to clamp the workpiece 100 to be inspected, and the workpiece 100 to be inspected can move flexibly within a certain range under the clamping of the multi-degree-of-freedom fixture 1; The driving mechanism 2 is used to drive the first positioning shaft 3 and the second positioning shaft 4 to approach each other or move away from each other; The first positioning shaft 3 and the second positioning shaft 4 can be plugged and matched in the process of approaching each other, and can be plugged and matched with the first concentric hole 101 and the second concentric hole 102 of the workpiece 100 to be inspected, respectively.

[0024] In the above structure, the first positioning shaft 3 and the second positioning shaft 4 are customized shaft structures with high dimensional accuracy, and the two are used as standard parts to inspect the workpiece 100 to be inspected. The workpiece 100 to be inspected can swing in a small range and float up and down, front and back under the clamping of the multi-degree-of-freedom fixture 1, so that the first positioning shaft 3 and the second positioning shaft 4 are respectively inserted into the first concentric hole 101 and the second concentric hole 102 of the workpiece 100 to be inspected.

[0025] The working principle of the above device is as follows: First, without inserting the workpiece 100 to be inspected, the driving mechanism 2 drives the first positioning shaft 3 and the second positioning shaft 4 to approach each other, ensuring that the first positioning shaft 3 and the second positioning shaft 4 can be plugged and matched in the process of approaching each other, thereby ensuring that the two are in a coaxial state; Next, the device is restored to an initial state, in which a gap at least large enough to accommodate the workpiece 100 to be inspected exists between the first positioning shaft 3 and the second positioning shaft 4; Subsequently, the workpiece 100 to be inspected is placed on the multi-degree-of-freedom fixture 1, and the workpiece 100 to be inspected is placed between the first positioning axis 3 and the second positioning axis 4; Afterwards, the driving mechanism 2 drives the first positioning shaft 3 and the second positioning shaft 4 to approach each other. At this time, the device is in the testing state. If the first positioning shaft 3 and the second positioning shaft 4 can be smoothly inserted into the first concentric hole 101 and the second concentric hole 102 respectively during the process of approaching each other, it means that the concentricity of the first concentric hole 101 and the second concentric hole 102 meets the requirements; If the first positioning shaft 3 and the second positioning shaft 4 are difficult to plug into or even stuck when approaching each other, and cannot be smoothly inserted into the first concentric hole 101 and the second concentric hole 102, it means that the concentricity of the first concentric hole 101 and the second concentric hole 102 does not meet the requirements.

[0026] It should be noted that the device provided in the present application is used to quickly inspect the workpiece to quickly determine whether the hole processing of the workpiece meets the concentricity requirements. The device cannot detect the specific value of the concentricity between the first concentric hole 101 and the second concentric hole 102.

[0027] Compared with the use of a three-coordinate measuring machine to inspect the concentricity of a circular hole, the device provided in this application has the advantages of low cost, short time, simple operation, etc., and can quickly inspect a large number of workpieces. The device does not rely on the professional level of the operator when in use, and is easy to promote and use.

[0028] Reference Figures 2 to 4 The circular hole concentricity rapid inspection device also includes a working platform 5, and the multi-degree-of-freedom fixture 1 and the driving mechanism 2 are installed on the working platform 5.

[0029] Furthermore, the driving mechanism 2 comprises: Two driving members 21, the two driving members 21 are symmetrically arranged and the power output ends of the two driving members 21 are respectively fixed to the first positioning shaft 3 and the second positioning shaft 4; Two connecting plates 22 are respectively fixed to the power output ends of the two driving members 21 , and the first positioning shaft 3 and the second positioning shaft 4 are respectively detachably connected to the two connecting plates 22 .

[0030] Specifically, the connecting plate 22 is fixed to the power output end of the driving member 21 by fasteners such as nuts, bolts, and joints; the first positioning shaft 3 and the second positioning shaft 4 are detachably connected to the two connecting plates 22 respectively by bolts.

[0031] In the above structure, the first positioning shaft 3 and the second positioning shaft 4 are detachably connected to the two connecting plates 22 respectively, so that different positioning shafts can be replaced for workpieces 100 to be inspected of different sizes, so that the device can detect workpieces of different sizes and improve the application range of the device.

[0032] Furthermore, the driving member 21 is a pneumatic cylinder or an oil cylinder; the driving mechanism 2 also includes a piston rod position detection structure, which is arranged on one side of the piston rod of the driving member 21 and can detect the movement speed and position of the piston rod.

[0033] The detection result of the piston rod position detection structure can be used to determine the difficulty of plugging the first positioning shaft 3 and the second positioning shaft 4 together during their approach, and whether the first positioning shaft 3 and the second positioning shaft 4 are stuck during the plugging process.

[0034] Specifically, a piston rod position detection structure is provided on one side of the piston rod of each driving member 21, and the two piston rod position detection structures are used to respectively detect the movement speed and position of the piston rods of the two driving members 21. The piston rod position detection structure includes a photoelectric sensor 24, a rack 25, and a test rod 23, wherein the test end of the photoelectric sensor 24 faces the tooth surface of the rack 25, the rack 25 is fixed to the circumference of the test rod 23, and the test rod 23 is arranged in parallel with the piston rod of the driving member 21 and the two act synchronously.

[0035] More specifically, the photoelectric sensor 24 is fixedly mounted on the support plate on the working platform 5; the cylinder body of the driving member 21 is fixedly mounted on the cylinder mounting plate on the working platform 5, and its piston rod is connected to the connecting plate 22 by fasteners such as joints and nuts; one end of the inspection rod 23 is fixed to the connecting plate 22 by fasteners such as nuts, and the other end of the inspection rod 23 slides through the cylinder mounting plate; a mounting plane is provided on the circumferential surface of the inspection rod 23, and the rack 25 is fixed on the mounting plane by countersunk screws, and the tooth surface of the rack 25 faces the photoelectric sensor 24.

[0036] When the piston rod of the driving member 21 pushes the positioning shaft to move, the inspection rod 23 moves synchronously with the piston rod of the driving member 21. In this process, the photoelectric sensor 24 detects the number of teeth that the inspection rod 23 passes when it stops. The position (extended length) of the inspection rod 23 is calculated by the number of teeth that it passes when it stops, and the moving speed of the inspection rod 23 is calculated by the number of teeth that it passes when it stops and the start and stop time of the inspection rod 23.

[0037] Specifically, when the first positioning shaft 3 and the second positioning shaft 4 are respectively inserted into the first concentric hole 101 and the second concentric hole 102 , the extended length of the inspection rod 23 is a known value.

[0038] If it is detected within the set time that the extended length of the inspection rod 23 reaches the above-mentioned known value, it means that the first positioning shaft 3 and the second positioning shaft 4 are successfully inserted into the first concentric hole 101 and the second concentric hole 102, and further indicates that the concentricity of the first concentric hole 101 and the second concentric hole 102 meets the requirements.

[0039] If after the set time, it is detected that the extended length of the inspection rod 23 is less than the above-mentioned known value, it means that the first positioning shaft 3 and the second positioning shaft 4 cannot be smoothly inserted into the first concentric hole 101 and the second concentric hole 102, and further indicates that the concentricity of the first concentric hole 101 and the second concentric hole 102 does not meet the requirements.

[0040] On the basis of the above structure, the circular hole concentricity rapid inspection device further includes two warning lights of different colors, one of which is used to indicate that the workpiece meets the concentricity requirement, and the other is used to indicate that the workpiece does not meet the concentricity requirement. The device provided in this embodiment can intuitively display the inspection results, and has no requirements on the professional level of the operator.

[0041] In addition, the driving member 21 may be equipped with a pressure regulating valve to adjust the output pressure of the driving member 21 .

[0042] As an optional embodiment, the circular hole concentricity rapid inspection device also includes a display placed on the work platform 5, through which the batch number, specifications and inspection data of the workpiece can be recorded and viewed, and the output pressure of the current device, the set extension length of the inspection rod 23 and the set inspection time and other data can also be viewed and adjusted.

[0043] Reference Figure 5 and Figure 6 The second positioning shaft 4 is of a hollow structure. A positioning hole 411 is provided at the end of the second positioning shaft 4 close to the first positioning shaft 3 . The positioning hole 411 is used for plugging and matching with the first positioning shaft 3 .

[0044] Furthermore, the first positioning shaft 3 includes a first core shaft portion 31 and a first inspection portion 32, the first core shaft portion 31 is used for plugging and matching with the second positioning shaft 4, and the first inspection portion 32 is used for plugging and matching with the first concentric hole 101; And / or, the second positioning shaft 4 includes a second core shaft portion 41 and a second inspection portion 42 , the second core shaft portion 41 is used for plugging and fitting with the first positioning shaft 3 , and the second inspection portion 42 is used for plugging and fitting with the second concentric hole 102 .

[0045] The outer diameter, length and precision of the first inspection part 32 and the second inspection part 42 can be adjusted according to different workpieces 100 to be inspected, and the concentricity of the outer diameter of the first inspection part 32 and the second inspection part 42 should at least meet the concentricity requirement of the workpiece 100 to be inspected.

[0046] In order to facilitate plugging, the periphery of the end surface of the first positioning shaft 3 facing the second positioning shaft 4, the periphery of the first inspection portion 32 and the periphery of the second inspection portion 42 are all provided with chamfers or rounded corners.

[0047] Reference Figure 7 and Figure 8 The multi-degree-of-freedom fixture 1 includes a mounting cylinder 11, a bracket 12 and a ball plunger 13, wherein: The installation tube 11 is a cylindrical structure with openings at both ends; The bracket 12 is connected to the bottom of the mounting tube 11; The ball plunger 13 is fixedly connected to the mounting tube 11 , and the ball end of the ball plunger 13 extends into the mounting tube 11 and can abut against the workpiece 100 to be inspected.

[0048] like Figure 8 As shown, there are multiple ball plungers 13 , which are divided into at least two groups of ball plunger groups distributed in sequence along the axial direction of the mounting tube 11 , and each group of ball plunger groups includes multiple ball plungers 13 distributed in sequence along the radial direction of the mounting tube 11 .

[0049] After the workpiece 100 to be inspected is inserted into the mounting tube 11 , supported by a plurality of ball plungers 13 , the workpiece 100 to be inspected is suspended in the mounting tube 11 , and its position and angle can be finely adjusted.

[0050] For workpieces 100 to be inspected with different outer diameters within a certain range, the length of the ball plunger 13 extending into the mounting tube 11 can be adjusted to adapt to different workpieces 100 to be inspected.

[0051] like Fig. 9 As shown, for a rocker arm type workpiece, a notch 111 may be provided on one side of the mounting tube 11 .

[0052] Continue to refer to Figure 8 The multi-degree-of-freedom fixture 1 further includes a slide bar 14 and a compression spring 15 and a slide seat slidably mounted on the slide bar 14, wherein: The two ends of the slide bar 14 are respectively fixed to two vertical plates on the working platform 5; The two ends of the compression spring 15 are respectively in contact with the slide seat and one of the vertical plates; The bottom of the bracket 12 is fixed on the slide.

[0053] When the workpiece 100 to be inspected needs to be installed into or removed from the installation cylinder 11 , the installation cylinder 11 is pulled to be moved out from between the first positioning shaft 3 and the second positioning shaft 4 , so as to facilitate the installation and removal of the workpiece 100 to be inspected.

[0054] In summary, the circular hole concentricity rapid inspection device provided in this embodiment can quickly inspect whether the concentricity of the hole on the workpiece meets the processing requirements, and also has the advantages of simple operation and low cost, and is easy to promote widely.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circular hole concentricity rapid testing device, characterized in that: It comprises a multi-degree-of-freedom fixture (1), a driving mechanism (2), a first positioning axis (3) and a second positioning axis (4), wherein: The multi-degree-of-freedom clamp (1) is used to clamp a workpiece (100) to be inspected, and the workpiece (100) to be inspected can move flexibly within a certain range when clamped by the multi-degree-of-freedom clamp (1); The driving mechanism (2) is used to drive the first positioning shaft (3) and the second positioning shaft (4) to move toward or away from each other; The first positioning shaft (3) and the second positioning shaft (4) can be plugged into and matched with each other during the process of approaching each other, and can be plugged into and matched with the first concentric hole (101) and the second concentric hole (102) of the workpiece (100) to be inspected, respectively.

2. The circular hole concentricity rapid testing device according to claim 1, characterized in that: The driving mechanism (2) comprises two driving members (21), the two driving members (21) are symmetrically arranged and the power output ends of the two driving members (21) are respectively fixedly connected to the first positioning shaft (3) and the second positioning shaft (4).

3. The circular hole concentricity rapid testing device according to claim 2, characterized in that: The driving mechanism (2) further comprises two connecting plates (22), wherein the two connecting plates (22) are respectively fixedly connected to the power output ends of the two driving members (21); The first positioning shaft (3) and the second positioning shaft (4) are respectively detachably connected to the two connecting plates (22).

4. The circular hole concentricity rapid testing device according to claim 2, characterized in that: The driving member (21) is a pneumatic cylinder or an oil cylinder; The driving mechanism (2) further comprises a piston rod position detection structure, which is arranged on one side of the piston rod of the driving member (21) and is capable of detecting the movement speed and position of the piston rod.

5. The circular hole concentricity rapid testing device according to claim 4, characterized in that: The piston rod position detection structure comprises a photoelectric sensor (24), a rack (25) and a test rod (23), wherein the test rod (23) is arranged in parallel with the piston rod of the driving member (21) and the two move synchronously, the rack (25) is fixed to the circumferential surface of the test rod (23), and the test end of the photoelectric sensor (24) faces the tooth surface of the rack (25).

6. The circular hole concentricity rapid testing device according to claim 1, characterized in that: The second positioning shaft (4) is of a hollow structure, and a positioning hole (411) is provided at the end of the second positioning shaft (4) close to the first positioning shaft (3), and the positioning hole (411) is used for plugging and matching with the first positioning shaft (3).

7. The circular hole concentricity rapid testing device according to claim 1, characterized in that: The first positioning shaft (3) comprises a first core shaft portion (31) and a first inspection portion (32), the first core shaft portion (31) being used for plugging and fitting with the second positioning shaft (4), and the first inspection portion (32) being used for plugging and fitting with the first concentric hole (101); And / or, the second positioning shaft (4) comprises a second core shaft portion (41) and a second inspection portion (42), the second core shaft portion (41) being used for plugging and fitting with the first positioning shaft (3), and the second inspection portion (42) being used for plugging and fitting with the second concentric hole (102).

8. The circular hole concentricity rapid testing device according to claim 7, characterized in that: The peripheries of the first inspection portion (32) and the second inspection portion (42) are both provided with chamfers or rounded corners.

9. The circular hole concentricity rapid testing device according to claim 1, characterized in that: The multi-degree-of-freedom fixture (1) comprises a mounting cylinder (11), a bracket (12) and a ball plunger (13), wherein: The installation tube (11) is a cylindrical structure with openings at both ends; The bracket (12) is connected to the bottom of the mounting tube (11); The ball head plunger (13) is fixedly connected to the mounting tube (11), and the ball head end thereof extends into the mounting tube (11) and is capable of abutting against the workpiece (100) to be inspected.

10. The circular hole concentricity rapid testing device according to claim 9, characterized in that: The number of the ball head plungers (13) is multiple, and the multiple ball head plungers (13) are divided into at least two groups of ball head plunger groups distributed in sequence along the axial direction of the installation tube (11), and each group of the ball head plunger groups includes multiple ball head plungers (13) distributed in sequence along the radial direction of the installation tube (11).

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