Stud inspection method and inspection apparatus

Abstract

The present invention provides an inspection method that allows for the application of both shear stress and tensile stress to a stud during the inspection process. [Solution] The method comprises a shear force application step of applying a shear force to a welded stud, and a measurement step of applying a tensile force to the stud in the state where a shear force has been applied by the shear force application step, while measuring the stud's resistance to the tensile force. The method also includes a fixing step of filling a filler between the fixing member that applies the shear force to the stud and the stud to fix the fixing member to the stud, and in the shear force application step, the shear force may be applied to the stud fixed to the stud by the fixing step via the fixing member.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for inspecting studs.

Background Art

[0002] Patent Document 1 discloses a holding device for a test piece that can apply a tensile stress to the test piece together with a shear stress.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, Patent Document 1 does not disclose an inspection for applying a tensile stress together with a shear stress to a welded stud.

[0005] Therefore, on one aspect, an object of the present invention is to provide an inspection method and the like that can perform an inspection for applying a tensile stress together with a shear stress to a stud.

Means for Solving the Problems

[0006] In one aspect, a shear force applying step of applying a shear force to a welded stud; a measurement step of measuring the stud strength against the tensile force while applying a tensile force to the stud in a state where the shear force is applied by the shear force applying step; and an inspection method for a stud including the above is provided.

Effects of the Invention

[0007] In one respect, according to the present invention, it is possible to perform an inspection on a stud by applying tensile stress along with shear stress. [Brief explanation of the drawing]

[0008] [Figure 1] This is a front view showing the configuration of the inspection device used in the stud inspection method of this embodiment. [Figure 2] This is a top view showing the configuration of the inspection device used in the stud inspection method of this embodiment. [Figure 3] This is a diagram showing the configuration of the processing unit installed in the inspection device. [Figure 4] This figure shows an example of the load-bearing capacity characteristics (combined stress) required for studs. [Figure 5] This is a bottom view showing the structure reinforced with braces. [Figure 6] This is a partially enlarged view of Figure 5. [Figure 6A] Figure 6 is a side view taken from the direction of the line VIa-VIa. [Figure 7] This is a partially enlarged view of Figure 6. [Figure 7A] Figure 7 is a side view taken from the direction of line VIIa-VIIa. [Modes for carrying out the invention]

[0009] Figure 1 is a front view showing the configuration of the inspection device in the stud inspection method of this embodiment, Figure 2 is a top view showing the configuration of the inspection device in the stud inspection method of this embodiment, and Figure 3 is a diagram showing the configuration of the processing unit provided in the inspection device.

[0010] In the stud inspection method of this embodiment, a tensile force is applied to the stud 30 (threaded root diameter stud) welded to the stud base material 100A using a testing machine 80 (Figure 3), and the axial stress is measured. In parallel with the measurement of the axial stress, a shear force is applied to the stud 30, and the shear stress is measured using a load cell 59.

[0011] As shown in Figures 1 and 2, in the stud inspection method of this embodiment, a reinforcing plate 10A, which serves as a fixing member and has bolt holes through which the stud 30 is inserted, is placed on top of the stud base material 100A. The stud base material 100A is fixed to the stud base material 100A by nuts 54 and washers 54a that are screwed onto the stud 30. When the nuts 54 are fastened, a filler 53 (Figure 1), such as an adhesive (curable resin), is filled between the stud 30 and the bolt holes of the reinforcing plate 10A. As the filler 53 hardens, the reinforcing plate 10A is bearing-joined to the stud 30. Alternatively, the filler 53 may be omitted, and the reinforcing plate 10A may be friction-joined to the stud 30.

[0012] The stud base material 100A is fixed to the base 51 by bolts 52.

[0013] Furthermore, in this embodiment, a shear force is applied to the stud 30 by pushing the reinforcing plate 10A to the left in Figures 1 and 2.

[0014] As shown in Figures 1 and 2, the inspection device comprises a long nut 56 fixed to a base 55, a bolt 57 for inputting shear force that is screwed into the long nut 56, a spherical seat 58 that abuts the tip of the bolt 57 (the left end in Figures 1 and 2), and a load cell 59 that abuts the spherical seat 58. The base 55, long nut 56, bolt 57, spherical seat 58, and load cell 59 constitute a shear force application mechanism. The load cell 59 is sandwiched between the reinforcing plate 10A and the spherical seat 58 in the left-right direction in Figures 1 and 2, and measures the shear force applied to the stud 30.

[0015] As shown in FIG. 3, the processing unit 70 of the inspection apparatus includes an axial stress acquisition unit 71, a shear stress acquisition unit 72, a storage unit 73, and a calculation unit 74. The axial stress acquisition unit 71 acquires the axial stress which is the measured value of the testing machine 80. The shear stress acquisition unit 72 acquires the shear stress which is the measured value of the load cell 59. The storage unit 73 stores various data necessary for the processing in the processing unit 70, and also stores the measured values acquired by the axial stress acquisition unit 71 and the shear stress acquisition unit 72. The calculation unit 74 executes necessary calculations based on the data and measured values stored in the storage unit 73, and outputs the calculation results.

[0016] Next, the procedure of the stud inspection method of this embodiment will be described.

[0017] First, the stud base material 100A in a state where the attaching plate 10A is pressure-bonded to the stud 30 is set on the base 51. Also, the stud 30 is attached to the testing machine 80 so that testing by the testing machine 80 becomes possible.

[0018] Next, the bolt 57 is rotated to apply a predetermined value of shear force to the stud 30 as an initial value. The initial value can be grasped as the measured value of the load cell 59.

[0019] Next, the testing by the testing machine 80 is started. The axial stress acquisition unit 71 sequentially acquires the axial stress which is the measured value of the testing machine 80. The shear stress acquisition unit 72 sequentially acquires the shear stress which is the measured value of the load cell 59 in association with the simultaneous axial stress, and the storage unit 73 sequentially stores these measured values. Note that during the testing by the testing machine 80, the measured value of the load cell 59 can change without maintaining the initial value.

[0020] By repeating the testing by the testing machine 80 while changing the initial value of the shear force, the measured values can be accumulated in the storage unit 73.

[0021] Next, the calculation unit 74 executes necessary calculations. For example, based on the data and measured values stored in the storage unit 73, the relationship between the shear stress degree and the axial stress degree of the stud 30 can be calculated and output.

[0022] Figure 4 shows an example of the load-bearing characteristics (combined stress) required for a stud.

[0023] In Figure 4, the vertical axis corresponds to axial stress and the horizontal axis corresponds to shear stress. In the example in Figure 4, a line 90 is shown indicating the axial stress required for the stud 30 according to the shear stress, representing the required load-bearing strength characteristics of the stud 30. For example, if the shear stress of the stud 30 calculated by the calculation unit 74 exceeds the value indicated by line 90 within a predetermined range of axial stress, it can be determined that the load-bearing strength characteristics of the stud 30 meet the standard.

[0024] Thus, according to this embodiment, it is possible to perform an inspection on the stud 30 by applying both shear stress and tensile stress. Therefore, it is possible to inspect the load-bearing capacity characteristics of the stud 30 under conditions in which both shear stress and tensile stress are applied.

[0025] Next, we will describe an example in which tensile stress is applied along with shear stress to studs 31 and 33 (Figures 6-7A) that are stud-welded to structure 100 (Figure 5). Note that the following description merely illustrates an example of a structure in which tensile stress is applied along with shear stress to studs, and does not limit the scope of application of the inspection method in this embodiment (e.g., the intended use of the studs). Figure 5 is a bottom view showing the structure reinforced by braces, Figure 6 is a partially enlarged view of Figure 5, Figure 6A is a side view of Figure 6 seen from the direction of line VIa-VIa, Figure 7 is a partially enlarged view of Figure 6, and Figure 7A is a side view of Figure 7 seen from the direction of line VIIa-VIIa.

[0026] As shown in Figure 5, the structure 100 comprises beams 101 and 102 extending in mutually orthogonal directions to form a rectangular frame structure, and a member 103 extending in a direction parallel to beam 102 and bridging between beams 101. Beams 101 and 102 are made of H-shaped steel.

[0027] In the example shown in Figure 5, the structure 100 is reinforced by a brace comprising a brace member 11. One end of the brace member 11 is connected to the beam 101 via a mounting portion 12, and the other end of the brace member 11 is connected to the member 103 via a mounting portion 14.

[0028] As shown in Figures 6 and 6A, four studs 31 are welded to the beam 101 corresponding to bolt holes provided in the mounting portion 12, and the mounting portion 12 is fastened to each stud 31 using nuts 31a and washers 31b of a predetermined diameter (in this example, rectangular washers as shown in Figure 6A).

[0029] Furthermore, a hole 11a is formed at one end of the brace material 11, and a flat plate-shaped mounting portion 12 is fastened through the hole 11a. By forming a hole in the mounting portion 12 that corresponds to the hole 11a, this hole can be used for fastening.

[0030] As shown in Figures 7 and 7A, a pair of studs 33 are welded to member 103, and the mounting portion 14 is fastened to member 103 via the studs 33. Note that, similar to the nuts 31a and washers 31b used for fastening with studs 31, nuts and washers of a predetermined diameter may be used for fastening with the studs 33.

[0031] Furthermore, a hole 11b is formed on the other end of the brace material 11, and the mounting portion 14 is fastened through the hole 11b. By forming a hole in the mounting portion 14 that corresponds to the hole 11b, this hole can be used for fastening.

[0032] Furthermore, when fastening the mounting portion 12 to the beam 101 via the stud 31, a filler such as an adhesive (curable resin) may be filled between the bolt hole of the mounting portion 12 and the stud 31 before fastening with a nut 31a and washer 31b. The hardening of the filler allows the mounting portion 12 to be bearing-jointed to the beam 101. In this case, the stress applied to the multiple (four in the example of Figure 2) studs 31, especially the shear stress, can be equalized. The same applies when fastening the mounting portion 14 to the member 103 via the stud 33. Bearing-jointing using a filler may also be employed for other fastening parts.

[0033] As described above, according to this embodiment, it is possible to perform an inspection on the stud 30 by applying both shear stress and tensile stress. Therefore, it is possible to inspect the load-bearing capacity characteristics of the stud 30 under conditions in which both shear stress and tensile stress are applied.

[0034] Although the embodiments have been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope of the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above. [Explanation of Symbols]

[0035] 10A Splice 30 studs 55 base 56 Long nuts 57 volts 58 Ball seat 59 Load Cells 80 Testing Machines 100A Stud base material

Claims

1. A step of applying shear force to a welded stud, A measurement step is performed in which a tensile force is applied to the stud, which has been subjected to a shear force by the shear force application step, and the stud's resistance to the tensile force is measured. A method for inspecting studs equipped with the following features.

2. The fixing step includes filling a filler between the fixing member that applies the shear force to the stud and the stud to fix the fixing member to the stud, The method for inspecting a stud according to claim 1, wherein in the step of applying shear force, the shear force is applied to the stud, which has been fixed to the stud by the fixing step, via the fixing member.

3. An inspection device used in a stud inspection method for measuring the stud's resistance to a tensile force while applying a tensile force to a stud that has been subjected to a shear force, An inspection device comprising a shear force application mechanism that applies a shear force to a stud whose stud strength against tensile force is being measured.

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