Nut fixing device and fixing method for fixing nut to inner surface of pipe member

Abstract

The nut fixing device of the present application is a device capable of fixing a nut to the inner surface of a pipe member having a small inner diameter, characterized by comprising: a unit case (10) inserted into the inside of the pipe member; a rotating shaft (11) extending from the unit case (10) to the outside of the pipe member; a cam fixed to the rotating shaft (11) inside the unit case (10); and a nut holder (18) advanced toward the inner surface of the pipe member from the unit case (10) by rotation of the cam. A pressure receiving member abutting against the inner surface of the pipe member is provided on the surface opposite to the nut holder (18).

Description

Technical Field

[0001] The present invention relates to a nut fixing device and a fixing method for fixing a nut to the inner surface of a pipe component. Background Technology

[0002] As part of automotive lightweighting, the use of tubular components with hollow cross-sections, such as aluminum extrusion parts or steel tubes, is gradually increasing. Furthermore, to mount other components on the surface of these tubular components, a technique is required to secure nuts to the inner surface of the tubular component.

[0003] As a nut fixing device for fixing a nut to the inner surface of a pipe component, the technology described in Patent Document 1 is known. Figure 11 This is a cross-sectional view showing its general structure, which is as follows: A punch 2 with a beveled bottom is provided at the front end of the shaft 1 inserted inside the pipe component P. A piercing nut is supplied to the punch 2 through a nut supply channel 3. The punch 2 is raised by inserting a sheet pile 4 with a wedge-shaped beveled end into the bottom of the shaft 1, thereby pressing in the piercing nut. In addition, the upper surface of the pipe component P is pressed by a die 5, and the piercing nut is riveted and fixed to the inner surface of the pipe component P by the punch 2 and the die 5.

[0004] However, the existing device has the following problems: it requires a shaft 1 for the punch 2 and sheet pile 4 to be built into, and can only be used for pipe components P with an inner diameter larger than shaft 1. Furthermore, in order to rivet the piercing nut to the wall of pipe component P by adjusting the sheet pile 4 and raising the piercing nut and punch 2 from the inside of pipe component P, the punch 2 and die 5 need to be synchronized. If their timing is off, the nut mounting surface of pipe component P will be misaligned. In addition, since the outer diameter of shaft 1 is necessarily smaller than the inner diameter of pipe component P, shaft 1 is in a cantilever state when fixing the nut, and thus tilts due to the fixed load, potentially preventing proper riveting and fixing of the nut. To avoid this cantilever state, a separate mechanism is needed to ensure close contact between the shaft and pipe component and the floor surface.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 4268952 Summary of the Invention

[0008] Therefore, the purpose of this invention is to solve the existing problems and provide a nut fixing device and method that can fix a nut to the inner surface of a pipe component with an inner diameter smaller than that of existing pipe components, and can suppress the deformation of the nut mounting surface of the pipe component P.

[0009] The nut-fixing device of the present invention, which is completed to solve the above-mentioned problems, is characterized by comprising: a unit box inserted into the interior of the pipe component; a rotating shaft extending from the unit box to the exterior of the pipe component; a cam fixed to the rotating shaft inside the unit box; and a nut retainer that advances from the unit box toward the interior surface of the pipe component by rotation of the cam.

[0010] Furthermore, it is preferable to adopt a structure in which the bearing supporting the rotating shaft is connected to the unit box, and it is also preferable to adopt a structure in which a pressure-bearing member is provided on the side of the unit box opposite to the nut retainer, abutting against the inner surface of the tube component.

[0011] Furthermore, the nut-fixing method of the present invention, which was completed to solve the above-mentioned problems, is characterized in that, using the nut-fixing device described above, the nut is inserted into the inside of the pipe component in such a way that it is held in place by its nut retainer. A rotating shaft is driven from the outside of the pipe component to rotate the cam, causing the nut retainer to move toward the inner surface of the pipe component so that the nut is in close contact with the inner surface of the pipe component. Then, a die disposed at the outer periphery of the pipe component is pressed into the pipe component, thereby fixing the nut to the inner surface of the pipe component.

[0012] In addition, preferably, the pressure-bearing component on the side opposite to the nut retainer of the unit box abuts against the inner surface of the tube, thereby preventing the pressure of pressing the mold into the tube component from causing deformation of the tube component.

[0013] Invention Effects

[0014] According to the present invention, the nut is inserted into the tube component in such a way that it is held in place by a nut retainer. A cam is used to advance the nut retainer toward the inner surface of the tube component, bringing the nut into close contact with the inner surface of the tube component. Then, a die positioned on the outer periphery of the tube component is pressed into the tube component, thereby fixing the nut to the inner surface of the tube component. Therefore, a shaft as in the prior art is not required; only a unit box and a rotating shaft need to be inserted into the tube component. Thus, the nut can be fixed to the inner surface of a tube component with an inner diameter smaller than that of a tube component in the prior art.

[0015] Furthermore, according to the present invention, as long as the cam of the device is rotated to the mounting position in advance so that the nut is in close contact with the inner surface of the tube component before the die is activated, there is no need to synchronize the punch and die as in the prior art. Therefore, deformation of the nut mounting surface of the tube component P can be suppressed.

[0016] Furthermore, if the pressure-bearing component on the opposite side of the unit box to the nut retainer abuts against the inner surface of the tube to withstand the pressure of pressing the mold into the tube component, the device will not tilt inside the tube component as in the prior art, and the nut can be installed normally. Attached Figure Description

[0017] Figure 1 This is a perspective view of the nut fixing device according to the embodiment.

[0018] Figure 2 This is a front view of the nut fixing device according to the embodiment.

[0019] Figure 3 yes Figure 2 AA sectional view.

[0020] Figure 4 This is a cross-sectional view showing the usage status.

[0021] Figure 5 These are the top view and sectional view of the piercing nut.

[0022] Figure 6 It is a cross-sectional view showing a piercing nut inserted into the inner surface of a pipe component.

[0023] Figure 7 It is a cross-sectional view showing the state in which the nut retainer and pressure-bearing component are in close contact with the inner surface of the pipe component P.

[0024] Figure 8 It is a cross-sectional view showing the state after the die has been lowered.

[0025] Figure 9 It is a cross-sectional view showing the state after the die has been raised.

[0026] Figure 10 This is a cross-sectional view showing the state in which the piercing nut is fixed to the inner surface of the pipe component.

[0027] Figure 11 It is a schematic cross-sectional view representing the prior art. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below.

[0029] Figure 1 This is a perspective view of the nut fixing device according to the embodiment. Figure 2 This is its main view. Figure 3 yes Figure 2 A sectional view of section AA. 10 is a unit box inserted inside the pipe component P, with a rotating shaft 11 and a cam 12 fixed to the rotating shaft 11 by a key at its center. In this embodiment, the cam 12 is an elliptical or oblong cam.

[0030] The rotating shaft 11 extends from the unit housing 10 to the outside of the tube component P, and is supported by bearings 13 and intermediate bearings 14 for free rotation. Bearing 13 has left and right extending feet 15, such as... Figure 4 As shown, the base 16 is fixed to the outside of the opening of the tube component P. The intermediate bearing 14 is formed with an outer diameter the same as that of the unit box 10 so that it can be inserted into the interior of the tube component P. The unit box 10, the intermediate bearing 14, and the bearing 13 are connected as one unit by means of the connecting member 17. The rotating shaft 11 is rotated by a manual handle or a motor.

[0031] like Figure 3 As shown, the unit box 10 has openings at the top and bottom, and a nut retainer 18 is provided at the top, which is exposed and recessed relative to the unit box 10 by the rotation of the cam 12. The nut retainer 18 is constructed such that its upper surface is a circular recessed nut retaining portion 19, which can retain various nuts such as piercing nuts and press-in nuts. In this embodiment, as Figure 1 As shown, the nut retainer 18 is approximately square, as... Figure 3 As shown, the outer peripheral surface 20 can be exposed or submerged in the vertical direction when it abuts against the upper opening of the unit box 10.

[0032] On the side of the unit box 10 opposite to the nut retainer 18, a pressure-bearing member 21 is provided that abuts against the inner surface of the pipe member P. The pressure-bearing member 21 can also be exposed or submerged in the vertical direction by means of the cam 12 and the pressure-bearing member retraction mechanism 35, with its outer peripheral surface 22 abutting against the lower opening of the unit box 10.

[0033] Next, a nut-fixing method for fixing a nut to the inner surface of a pipe component using the nut-fixing device of the present invention will be described.

[0034] In this embodiment, Figure 5 The piercing nut 30 shown is fixed to the inner surface of a tube component P made of a quadrilateral aluminum extrusion part. The piercing nut 30 includes: an annular stamped portion 32 formed on the outer periphery of the internal thread portion 31; an annular groove portion 33 formed on the outer periphery of the annular stamped portion 32; and a support surface 34 formed on the outer periphery of the annular groove portion 33. As shown, the annular stamped portion 32 and the support surface 34 are set to the same height.

[0035] First, such as Figure 6 As shown, the piercing nut 30 is placed in the nut holding portion 19 of the nut holder 18, and the unit box 10 is inserted into the interior of the pipe component P. At this time, the cam 12 is in a horizontal position with its major diameter horizontal, and the nut holder 18 and the pressure bearing component 21 are in a position retracted towards the inside of the unit box 10.

[0036] Next, as Figure 7 As shown, the rotating shaft 11 is rotated so that the major axis of the cam 12 is in the vertical direction. The rotation of the cam 12 pushes the outer nut retainer 18 outward, causing the annular stamped portion 32 and the support surface 34, which are the upper surfaces of the piercing nut 30, to come into close contact with the upper inner surface of the tube component P. Additionally, the pressure-bearing member 21 also comes into close contact with the lower inner surface of the tube component P. By setting it to be the same as the inner diameter of the tube component P, the unit box 10 is reliably fixed inside the tube component P in a way that prevents it from wobbling.

[0037] Next, as Figure 8 As shown, a die 25, positioned on the outer periphery of the pipe component P, is pressed into the pipe component P, forming a through hole by stamping. The metal material around the through hole undergoes plastic flow, flowing to the annular groove 33 of the piercing nut 30, thereby fixing the piercing nut 30 to the inner surface of the pipe component P. Since the piercing nut 30 is reliably held by the unit housing 10, it is securely fixed. Furthermore, because the pressure-bearing member 21 abuts against the inner surface of the pipe component P, deformation of the pipe component P due to the pressure exerted by the die 25 is prevented.

[0038] Then, as Figure 9 As shown, the mold 25 is raised and the rotating shaft 11 is rotated so that the major axis of the cam 12 is oriented laterally, thereby causing the nut retainer 18 and the pressure bearing member 21 to retract, and then the unit box 10 is pulled out from the tube member P. Figure 10 This shows the state in which the piercing nut 30 is fixed to the inner surface of the pipe component P.

[0039] In the above embodiment, a piercing nut 30 with an annular stamped portion 32 and a support surface 34 formed at the same height is fixed. The piercing nut 30 of this embodiment has the advantage that it can be fixed using a die 25 while being held by the inside of the tube member P. However, the type of nut is not limited to this; in addition to a typical piercing nut where the annular stamped portion 32 is higher than the support surface 34, press-fit nuts, weld nuts, etc., can also be fixed. When fixing these nuts, it is sufficient that the nut retainer 18 can be moved using the cam 12.

[0040] In addition, in the above embodiment, a square aluminum extrusion component was used as the tube component P. However, if the shape of the unit box 10 is changed, it can also be applied to a tube component with a circular cross-section.

[0041] As explained above, according to the present invention, no setting is required. Figure 11The shafts for the punch and sheet pile are integrated, allowing the nut to be secured even on the inner surface of the smaller-diameter pipe component P, compared to existing technologies. Furthermore, since the die 25 only needs to be operated after the nut is held on the inner surface of the pipe component P, synchronization of the die is unnecessary. Additionally, since the unit box 10 can be reliably secured inside the pipe component P, it also offers several advantages, such as suppressing deformation of the nut mounting surface of the pipe component P.

[0042]

Example

[0043] The following are embodiments of the present invention.

[0044] Using the fixing device and piercing nut described in the above embodiments, a test was conducted to fix a piercing nut with a diameter of 22.5 mm and a thickness (total height) of 9 mm onto the inner surface of an aluminum extrusion part with a cross-section of 60 mm × 60 mm and a plate thickness of 2 mm. The aluminum extrusion part was cut to a length of 100 mm, and the piercing nut was fixed at the center position along its length. The pressing load of the die was 40 kN.

[0045] The free-spinning torque of the fixed piercing nut was measured using a dial torque wrench. Additionally, the engagement force (pull-out load) of the fixed piercing nut was determined using a tensile-compression testing machine. The results showed that the average free-spinning torque was 30 Nm, consistent with the case of fixing piercing nuts in open-section aluminum extrusion parts using existing methods. Furthermore, the average engagement force was 3.5 kN, therefore, consistent with the case of fixing piercing nuts in open-section aluminum extrusion parts using existing methods. The number of samples was set to N = 3 for all samples.

[0046] Next, the changes in the outer and inner diameters of the quadrilateral aluminum extrusion component were measured using vernier calipers. With the gap between the piercing nut and the inner surface of the tube set to zero, as in the embodiment described, the change in outer diameter was 0.02 mm and the change in inner diameter was 0.04 mm, both extremely small. Furthermore, it was confirmed that by forcefully pressing the piercing nut against the inner surface of the tube using a cam, both the changes in outer and inner diameters could be reduced to zero.

[0047] Explanation of reference numerals in the attached figures

[0048] P-pipe components

[0049] 1 axis

[0050] 2 stamping heads

[0051] 3-nut supply path

[0052] 4 sheet piles

[0053] 5. Pressing mold

[0054] 10-unit box

[0055] 11 rotating axes

[0056] 12 Cams

[0057] 13 bearings

[0058] 14 intermediate bearings

[0059] 15 feet

[0060] 16 bases

[0061] 17 Connecting Components

[0062] 18 Nut Retainer

[0063] 19 Nut Retention Section

[0064] 20 outer perimeter

[0065] 21 Pressure-bearing components

[0066] 22 outer perimeter

[0067] 30 puncture nut

[0068] 31 internal thread

[0069] 32 Ring-shaped stamping section

[0070] 33 Annular groove section

[0071] 34 support surfaces

[0072] 35 Pressure-bearing component retraction mechanism

Claims

1. A nut fixing device for fixing a nut to the inner surface of a pipe component, characterized in that, have: Unit box, which is inserted into the inside of the tube component; rotating shaft, which extends from the unit box to the outside of the tube component; elliptical or oblong cam, which is fixed to the rotating shaft inside the unit box; And a nut retainer, which advances from the unit box toward the inner surface of the tube component by the rotation of the cam.

2. The nut fixing device for fixing a nut to the inner surface of a pipe component according to claim 1, characterized in that, The bearing supporting the rotating shaft is configured to be connected to the unit housing.

3. The nut fixing device for fixing a nut to the inner surface of a pipe component according to claim 1 or 2, characterized in that, On the side of the unit box opposite to the nut retainer, there is a pressure-bearing component that abuts against the inner surface of the pipe component.

4. A method for fixing a nut to the inner surface of a pipe component, characterized in that, Using the nut fixing device of claim 1 for fixing a nut to the inner surface of a pipe component, the nut is inserted into the pipe component in such a way that it is held in place by its nut retainer. An elliptical or oblong cam is rotated by driving a rotating shaft from the outside of the pipe component, causing the nut retainer to advance toward the inner surface of the pipe component so that the nut is in close contact with the inner surface of the pipe component. Then, a die disposed on the outer periphery of the pipe component is pressed into the pipe component, thereby fixing the nut to the inner surface of the pipe component.

5. The nut-fixing method for fixing a nut to the inner surface of a pipe component according to claim 4, characterized in that, The pressure-bearing component on the opposite side of the unit box from the nut retainer abuts against the inner surface of the pipe to prevent deformation of the pipe component due to the pressure of pressing the mold into the pipe component.

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