Portable tapping soft clamp capable of improving machining precision and efficiency

Abstract

The utility model relates to the machining technology of composite nuts, in particular to a portable tapping soft clamp capable of improving machining precision and efficiency. The technical problems that when a composite nut is tapped at present, a plating layer is peeled and falls off, thread deflection is prone to occurring, and the tapping efficiency is low are solved. A convenient tapping soft clamp capable of improving machining precision and efficiency comprises a clamp body, a soft clamping sleeve, a rapid guiding and positioning device, a guiding sleeve, a positioning pin and a handle. A guide rail is arranged on one side of the clamp body, and at least one mounting hole and a positioning pin hole are further formed in the clamp body from the side; the rapid guiding and positioning device is provided with a sliding groove matched with the guide rail, and an installation guide hole and a positioning guide hole are further formed in the rapid guiding and positioning device. The mounting guide hole and the positioning guide hole are through holes; the guide sleeve is installed in the installation guide hole, and the positioning pin positions the clamp body and the rapid guiding and positioning device through the positioning pin hole and the positioning guide hole.

Description

Technical Field

[0001] The utility model relates to a processing technology for composite nuts, in particular to a convenient tapping soft clamp capable of improving processing precision and efficiency. Background Art

[0002] Composite nuts are widely used for fastening and connection in military and civilian applications. They offer low cost, reliable connections, and prevent loosening after tightening. Composite nuts typically consist of a plated metal nut and a non-metallic bushing. The plated metal nut has a stepped hole, within which a thin-walled non-metallic bushing is inserted. The non-metallic bushing is then enclosed by a closed end face. The internal thread of the composite nut is composed of two materials, the non-metallic bushing and the plated metal, forming a single, integral thread. The internal thread consists of one non-metallic section and one metal section, with thread accuracies typically reaching 4H, 5H, or 4H5H.

[0003] The process flow of composite nuts is generally as follows: machining metal nuts, machining non-metallic bushings, and not processing internal threads when machining metal nuts; assembly, the non-metallic bushing is assembled into the stepped hole of the metal nut; closing, closing with a special closing tool on a lathe, thereby fixing the non-metallic bushing in the metal nut hole; tapping, the general tapping method for composite nuts is bench tapping, when tapping, clamp the nut on a flat-nose pliers, clamp the nut by tightening the flat-nose pliers, tap with a tap, and apply torque to the tap with a wrench to complete the tapping (one section of the thread length is non-metallic and the other section is metal).

[0004] The main problems encountered during the production process are: the coating peels and falls off when clamping the coated nuts with flat-nose pliers; the threads of the combination of metal and non-metal are prone to thread deflection during tapping; the tapping efficiency is low, the thread accuracy after tapping does not meet the requirements, and the product qualification rate is low. Utility Model Content

[0005] The utility model aims to solve the technical problems of peeling and shedding of the coating, easy generation of thread deflection and low tapping efficiency when tapping composite nuts, and provide a convenient tapping soft clamp that improves processing accuracy and efficiency.

[0006] The utility model is realized by adopting the following technical scheme: a convenient tapping soft clamp for improving processing accuracy and efficiency, comprising a clamping body, a quick guide positioning device and a guide sleeve; the clamping body and the quick guide positioning device can slide and position relative to each other; at least one mounting hole is opened on the clamping body, and at least one mounting guide hole corresponding to the mounting hole is opened on the quick guide positioning device, and the mounting guide hole is a through hole; the guide sleeve is coaxial with the mounting guide hole and is installed in the mounting guide hole.

[0007] The soft fixture can be used to tap high-precision internal threads conveniently and efficiently. The soft fixture clamps quickly and reliably and will not damage workpieces with surface coatings. The sliding quick guide positioning device can tap the internal threads of multiple workpieces. The fixture has high positioning accuracy. The fixture can be used to tap high-precision internal threads of metal and non-metal combinations.

[0008] Furthermore, a soft jacket made of polytetrafluoroethylene is provided in the mounting hole of the clamp body, and a small clearance is formed between the soft jacket and the mounting hole.

[0009] Furthermore, the mounting hole has a stepped hole structure with a large inner diameter in the front half and a small inner diameter in the rear half. The soft jacket is installed in the front half of the mounting hole, and the length of the soft jacket is the same as that of the front half of the mounting hole.

[0010] Furthermore, the front half of the mounting hole and the mounting guide hole are both hexagonal holes, and the soft jacket is a hexagonal structure; radial grooves are opened radially outward on the six corners of the hexagonal structure of the soft jacket; one end of the guide sleeve extends radially outward with a limited section, which is used to be stuck on the outside of the mounting guide hole port.

[0011] Furthermore, the front end face of the clamp body is provided with a guide rail, the axial direction of the mounting hole is arranged perpendicular to the front end face, and the clamp body is also provided with a positioning pin hole perpendicular to the front end face; the rear end face of the quick guide positioning device is provided with a slide groove matching the guide rail, the axial direction of the mounting guide hole is arranged perpendicular to the rear end face, and the quick guide positioning device is also provided with a positioning guide hole perpendicular to the rear end face and corresponding to the positioning pin hole; the positioning guide hole is a through hole; the positioning between the clamp body and the quick guide positioning device is achieved by a positioning pin passing through the positioning guide hole and the positioning pin hole.

[0012] Furthermore, three mounting holes and three positioning pin holes are provided on the clamp body; the centers of the mounting holes and the positioning pin holes are located on the same horizontal line and the mounting holes and the positioning pin holes are arranged at intervals; the quick guide positioning device is provided with a mounting guide hole and a positioning guide hole, and the centers of the mounting guide hole and the positioning guide hole are located on the same horizontal line.

[0013] Furthermore, the guide rails are a pair of dovetail guide rails, and the slide grooves are a pair of dovetail slide grooves; the mounting holes and positioning pin holes are opened between the pair of dovetail guide rails; the mounting guide holes and positioning guide holes are opened between the pair of dovetail slide grooves.

[0014] Furthermore, a hole is formed at the end of the positioning pin, and a handle is installed in the hole; the positioning pin is made of high-hardness steel with a hardness of HRC ≥ 60.

[0015] Furthermore, there is a transition fit between the guide sleeve and the installation guide hole.

[0016] Furthermore, the clamping body and the quick guide positioning device are both made of cast steel; the guide sleeve is made of cold die steel with a hardness of HRC≥60.

[0017] By designing a high-precision, high-efficiency and convenient tapping soft fixture, the utility model can achieve the following effects:

[0018] 1) Design of a high-precision, high-efficiency and convenient tapping soft fixture, which realizes direct contact and clamping between the soft sleeve and the composite nut in the fixture, avoiding the coating on the nut surface falling off or the workpiece surface being clamped due to improper clamping force, and can improve the product qualification rate.

[0019] 2) Design of high-precision, high-efficiency and convenient tapping soft fixture to achieve uniform and low clamping force, avoid nut deformation due to improper clamping force, ensure thread accuracy and improve product qualification rate.

[0020] 3) Design a high-precision, high-efficiency and convenient tapping soft fixture that can clamp multiple workpieces at a time, relatively reducing the number of clamping times; using the rapid guide positioning device in the fixture, the tap is installed in the installation guide hole of the guide sleeve, which can quickly tap. There will be no thread deflection after tapping, which improves product quality and greatly improves production efficiency. Compared with ordinary tapping methods, the efficiency can be increased by more than 3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the composite nut structure.

[0022] Figure 2 for Figure 1 AA cross-sectional view.

[0023] Figure 3 for Figure 2 Enlarged view of C in the middle.

[0024] Figure 4 A schematic diagram of the main structure of the portable tapping soft clamp described in the utility model.

[0025] Figure 5 for Figure 4 AA cross-sectional view.

[0026] Figure 6 for Figure 4 BB cross-sectional view.

[0027] Figure 7 Schematic diagram of the main structure of the clamp.

[0028] Figure 8 for Figure 7 CC cross-sectional view.

[0029] Figure 9 Schematic diagram of the soft jacket structure.

[0030] Figure 10 Schematic diagram of the main structure of the rapid guidance and positioning device.

[0031] Figure 11 for Figure 10 AA cross-sectional view.

[0032] Figure 12 Schematic diagram of the guide sleeve structure.

[0033] Figure 13 Schematic diagram of the positioning pin structure.

[0034] Figure 14 Schematic diagram of the handle structure.

[0035] Figure 15 A schematic diagram of the main structure of the utility model after clamping the composite nut.

[0036] 1-clamp body, 2-soft clamping sleeve, 3-quick guide positioning device, 4-guide sleeve, 5-locating pin, 6-handle, 7-composite nut;

[0037] 11-guide rail, 12-mounting hole, 13-locating pin hole; 31-slide groove, 32-mounting guide hole, 33-locating guide hole; 71-surface chrome plating, 72-bushing. DETAILED DESCRIPTION

[0038] The composite nut of one of our company's products is made of a chrome-plated 20MnVB metal nut and a nylon 1010 non-metallic bushing. The overall structure is a chrome-plated metal hexagonal nut on one end and a non-metallic bushing embedded in the metal nut on the other end. The non-metallic bushing is fixed in the metal hole by closing the end. The internal thread of the metal composite nut is a high-precision M10×1-4H5H thread, and the thread material is 20MnVB and nylon 1010. The main function of the composite nut composed of metal and non-metal is to connect and tighten, and to reduce vibration, noise and prevent loosening. For the specific structure, see Figure 1-3 shown.

[0039] The threads of composite nuts are usually clamped by fitters using flat-nose pliers and tapped with taps. In actual production, there are the following main deficiencies:

[0040] 1) When tapping, use flat-nose pliers to clamp the hexagonal plated metal nut. It is difficult to control the clamping force during the actual clamping process. During tapping, the plating at the clamping part of the nut often peels off, causing the product to be scrapped.

[0041] 2) The wall of the composite nut is thin, and it may be deformed when clamped with flat-nose pliers, causing the coating to fall off and the thread accuracy to fail to reach 4H5H.

[0042] 3) The thread of the composite nut is composed of non-metal and metal, one section is metal and the other section is non-metal. There is no positioning guide device during tapping. When tapping threads composed of dissimilar materials, the threads may deviate and the thread stop may fail.

[0043] 4) Composite nuts have an anti-loosening function and are generally disposable parts with large production batches. The existing technology clamps one nut at a time during tapping. At the same time, there is no positioning guide device for tapping, and the tap must be aligned with the bottom hole of the thread before tapping, which results in low tapping efficiency.

[0044] The present invention will be further described below with reference to actual examples.

[0045] In order to prevent the clamping from damaging the nut coating surface during tapping, and to prevent the tap from deflecting when tapping the internal thread of a combination of metal and non-metal materials, which would cause the thread to deflect and the thread accuracy to fall short of 4H5H accuracy, and to improve tapping efficiency and quality, a portable tapping soft fixture has been designed to improve accuracy and worker efficiency. Figure 4-6 shown.

[0046] The fixture consists of 6 special parts, including a clamping body, a soft clamping sleeve, a quick guide positioning device, a guide sleeve, a small-taper locating pin, and a handle. The clamping body is made of wear-resistant cast steel material. There are dovetail guide rails for guiding, hexagonal holes for installing soft clamping sleeves, and locating pin holes on the clamping body. The soft clamping sleeve is made of polytetrafluoroethylene and other hard non-metals. It is installed in the holes of the clamping body and is used to clamp the workpiece. The quick guide positioning device is made of cast steel material. The quick guide positioning device has a small and lightweight structure and has a dovetail groove, a guide positioning hole, and a guide mounting hole for installing the guide sleeve. The guide sleeve is made of cold die steel with a hardness of HRC ≥ 60. It is a locating sleeve for guiding the tap during tapping. The small-taper locating pin is made of high-hardness steel with a hardness of HRC ≥ 60 at the positioning part. It is used to accurately position the quick guide positioning device on the clamping body. The handle of the small-taper locating pin is made of ordinary steel and is installed on the locating pin handle for quick insertion and removal of the locating pin. The main components of the high-precision, high-efficiency and convenient tapping soft clamp are shown in the following schematic diagram. Figures 7 to 14 .

[0047] 1) Clamp body 1

[0048] like Figure 7 、 8 As shown, the clamp body 1 is made of cast steel, which has good wear resistance and mechanical properties. There are two dovetail guide rails on the clamp body, which play a guiding role, have high guiding accuracy, and are easy to operate. The fast guiding positioning device 3 can slide accurately on the guide rails. There are hexagonal holes for installing the soft clamping sleeve 2 and positioning pin holes for installing the positioning pin 5 on the clamp body 1, which can efficiently clamp the workpiece, and the positioning pin holes play a role in accurate positioning.

[0049] 2) Soft jacket 2

[0050] like Figure 9 As shown, the soft jacket 2 is made of non-metal with a certain hardness such as polytetrafluoroethylene. It is installed in the mounting hole of the clamp body 1 and is used to directly clamp the workpiece. The advantage of the soft jacket is that it can avoid the large force of tapping and damage the coating on the surface of the nut workpiece. The shape of the jacket is consistent with the shape of the clamped workpiece and has a transition fit. The material is non-metal and the clamping area is large, so the workpiece will not be deformed after clamping.

[0051] 3) Rapid guide positioning device 3

[0052] like Figure 10-11 As shown, the quick guide positioning device 3 is made of cast steel, which has good wear resistance and mechanical properties. The guide positioning device is small and lightweight, has two dovetail grooves, high guiding accuracy, and convenient guiding. The quick guide positioning device 3 is installed on the dovetail guide rail of the clamp body 1. By sliding the quick guide positioning device 3 to different positions, multiple nuts can be tapped.

[0053] 4) Guide sleeve 4

[0054] like Figure 12 As shown, guide sleeve 4 is made of cold die steel with a hardness of HRC ≥ 60. It is installed in the mounting guide hole of the quick guide positioning device 3 through a transition fit. This is a quick-change guide sleeve with high guiding accuracy. When tapping, the tap can be directly inserted into guide sleeve 4, without deflection of the tapped thread, and can produce high-precision 4H, 5H, and 4H5H threads.

[0055] 5) Positioning pin 5

[0056] like Figure 13 As shown, the locating pin 5 is made of high-hardness steel, with a hardness of HRC ≥ 60 at the locating portion. It functions to accurately position the quick guide locating device 3 within the locating hole of the clamp body 1. After positioning, the threaded bottom hole of the nut workpiece installed in the clamp body 1 and the hole of the quick guide locating device 3, in which the guide sleeve 4 is installed, are coaxial, ensuring that the threaded hole does not deflect after tapping. The shank of the slightly tapered locating pin 5 has a hole for installing a handle 6. The handle 6 is made of ordinary steel and is installed on the shank of the locating pin for quick insertion and removal of the locating pin.

[0057] 6) Handle 6

[0058] Figure 14 The handle 6 shown is made of ordinary steel and is installed on the handle of the positioning pin for quickly inserting and removing the positioning pin.

[0059] The specific use process of the high-precision, high-efficiency and convenient tapping soft fixture and the results of processing a composite nut of the company are as follows:

[0060] 1) The soft jacket is installed in the three inner hexagonal holes of the clamp body, and the two are transition fit.

[0061] 2) The composite nut is installed in the three hexagonal holes with soft jackets, and the two are matched with a small gap (such as Figure 15 shown).

[0062] 3) The two slides of the quick guide positioning device (with guide sleeve installed) are installed on the two guide rails of the clamping body and can slide freely, making it easy to clamp and position.

[0063] 4) Insert the handle into the hole of the small-taper locating pin, and at the same time insert the locating pin with the handle into the φ6 locating pin hole of the quick guide positioning device and the clamp body to play a limiting and positioning role.

[0064] 5) Install the tap into the installation guide hole and use the tap to tap the internal thread of M10×1-4H5H.

[0065] 6) Pull out the locating pin and move it to the next locating hole together with the quick guide locating device (with guide sleeve installed), insert the locating pin, and continue to tap the internal thread of the second composite nut.

[0066] 7) Repeat step 6) to tap the internal thread of the third composite nut.

[0067] Processing results: 120 composite nuts were processed and tested with an M10×1-4H5H thread plug gauge, with a 100% thread qualification rate. The surface coating of the nuts was inspected with a 10x magnifying glass, and there was no quality problem such as peeling or shedding of the coating, with a 100% qualification rate.

[0068] In short, the newly designed and manufactured high-precision, high-efficiency and convenient tapping soft fixture has a novel structure, strong practicality, and has achieved good results in use.

Claims

1. A convenient tapping soft fixture for improving machining accuracy and efficiency, characterized in that: The invention comprises a clamping body (1), a quick guide positioning device (3) and a guide sleeve (4); the clamping body (1) and the quick guide positioning device (3) can slide and position relative to each other; the clamping body (1) is provided with at least one mounting hole (12); the quick guide positioning device (3) is provided with at least one mounting guide hole (32) corresponding to the mounting hole (12), and the mounting guide hole (32) is a through hole; the guide sleeve (4) is coaxial with the mounting guide hole (32) and is mounted in the mounting guide hole (32).

2. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 1, characterized in that: A soft jacket (2) made of polytetrafluoroethylene is further provided in the mounting hole (12) of the clamp body (1), and a small clearance fit is formed between the soft jacket (2) and the mounting hole (12).

3. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 2, characterized in that: The mounting hole (12) is a stepped hole structure with a large inner diameter in the front half and a small inner diameter in the rear half, and the soft jacket (2) is mounted in the front half of the mounting hole (12).

4. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 3, characterized in that: The front half of the mounting hole (12) and the mounting guide hole (32) are both hexagonal holes, and the soft jacket (2) is a hexagonal structure; radial grooves are opened radially outward on the six corners of the hexagonal structure of the soft jacket (2); and one end of the guide sleeve (4) extends radially outward to a limited position.

5. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 4, characterized in that: The front end face of the clamp body (1) is provided with a guide rail (11), the axial direction of the mounting hole (12) is arranged perpendicular to the front end face, and the clamp body (1) is further provided with a positioning pin hole (13) perpendicular to the front end face; the rear end face of the quick guide positioning device (3) is provided with a slide groove (31) matching the guide rail (11), the axial direction of the mounting guide hole (32) is arranged perpendicular to the rear end face, and the quick guide positioning device (3) is further provided with a positioning guide hole (33) perpendicular to the rear end face and corresponding to the positioning pin hole (13); the positioning guide hole (33) is a through hole; the clamp body (1) and the quick guide positioning device (3) are positioned by a positioning pin 5 passing through the positioning guide hole (33) and the positioning pin hole (13).

6. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 5, characterized in that: The clamp body (1) is provided with three mounting holes (12) and three positioning pin holes (13); the centers of the mounting holes (12) and the positioning pin holes (13) are located on the same horizontal line and the mounting holes (12) and the positioning pin holes (13) are arranged at intervals; the quick guide positioning device (3) is provided with a mounting guide hole (32) and a positioning guide hole (33); the centers of the mounting guide hole (32) and the positioning guide hole (33) are located on the same horizontal line.

7. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 5 or 6, characterized in that: The guide rails (11) are a pair of dovetail guide rails, and the slide grooves (31) are a pair of dovetail slide grooves; the mounting holes (12) and the positioning pin holes (13) are opened between the pair of dovetail guide rails; and the mounting guide holes (32) and the positioning guide holes (33) are opened between the pair of dovetail slide grooves.

8. A portable tapping soft fixture for improving machining accuracy and efficiency as claimed in claim 5 or 6, characterized in that: The end of the positioning pin (5) is provided with a hole, in which a handle (6) is installed; the positioning pin (5) is made of high-hardness steel with a hardness of HRC ≥ 60.

9. A portable tapping soft fixture for improving machining accuracy and efficiency according to any one of claims 1 to 6, characterized in that: There is a transition fit between the guide sleeve (4) and the installation guide hole (32).

10. A portable tapping soft fixture for improving machining accuracy and efficiency according to any one of claims 1 to 6, characterized in that: The clamp body (1) and the quick guide positioning device (3) are both made of cast steel; the guide sleeve (4) is made of cold die steel with a hardness of HRC ≥ 60.

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