Anti-carburizing tool for thread part

Abstract

The utility model relates to the technical field of anti-carburizing tools, in particular to a threaded part anti-carburizing tool which comprises a threaded part, a bolt, refractory mortar and an end cover, the bolt is in threaded connection with the threaded part, and the refractory mortar is detachably connected to the connecting position of the bolt and the threaded part; the end cover is detachably connected to the bolt and covers the bolt and the refractory mortar, and a spring is fixedly connected to the top wall in the end cover; a through hole penetrating through the head and the tail is formed in the bolt, the through hole sequentially comprises an inner hexagonal hole, a V-shaped taper hole and a round hole from top to bottom, the diameter of the minimum end of the V-shaped taper hole is the same as that of the round hole, a solid ball with the diameter between the diameter of the maximum end of the V-shaped taper hole and the diameter of the minimum end of the V-shaped taper hole is arranged in the V-shaped taper hole, and the spring abuts against the solid ball. The anti-carburizing threaded hole has the advantages that the anti-carburizing effect of the threaded hole is improved, the service life of the internal thread is prolonged, and then the overall service life of a part is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of anti-carburization tools, and in particular to a threaded portion anti-carburization tool. Background Art

[0002] The existing threaded holes on gears or shaft parts are isolated by blocking them with bolts to prevent carburizing. However, due to the certain gap between the bolts and the screw holes, and the different thermal expansion coefficients at high temperatures caused by the different materials of the bolts and the screw holes, the gap between the bolts and the screw holes increases during heat treatment, resulting in unsatisfactory anti-seepage effect. Some threads are still hardened after carburizing, resulting in a short service life of the internal thread, which restricts the overall service life of the parts. Utility Model Content

[0003] In order to improve the anti-carburization effect of threaded holes, increase the service life of internal threads, and thus increase the overall service life of parts, the present application provides a threaded anti-carburization tool.

[0004] The present application provides a threaded anti-carburization tool that adopts the following technical solution:

[0005] A threaded portion anti-carburization tool comprises a threaded portion, a bolt and refractory clay. The bolt is threadedly connected to the threaded portion, and the refractory clay is detachably connected to the connection position between the bolt and the threaded portion.

[0006] Optionally, it further includes an end cover, which is detachably connected to the bolt and covers the bolt and the refractory mud, and a spring is fixedly connected to the top wall of the end cover;

[0007] The bolt is provided with a through hole that passes through the head and tail, and the through holes are, from top to bottom, a hexagonal hole, a V-shaped tapered hole and a round hole. The minimum end diameter of the V-shaped tapered hole is the same as the diameter of the round hole. A solid ball with a diameter between the maximum end diameter and the minimum end diameter of the V-shaped tapered hole is provided in the V-shaped tapered hole, and the spring abuts against the solid ball.

[0008] Optionally, the top of the side wall surrounding the bolt is provided with an external thread; the interior of the end cover is divided into a first concave cavity and a second concave cavity which are interconnected, the diameter of the first concave cavity is larger than the diameter of the second concave cavity and is located below the second concave cavity, and the first concave cavity cover is provided outside the refractory mud;

[0009] The inner side wall of the second concave cavity is threadedly connected to the outer wall of the bolt, and the spring is arranged on the top wall of the second concave cavity.

[0010] Optionally, the refractory mud is laid in a conical shape along the connection position between the nut and the threaded portion and solidified.

[0011] Optionally, a sleeve is fixedly connected to the top wall inside the end cover, and the spring is located inside the sleeve.

[0012] Optionally, the threaded portion is an internal threaded hole, the bolt includes a screw and a nut, the screw is inserted into the internal threaded hole and threadedly connected to the internal threaded hole, the nut is located outside the internal threaded hole and the diameter of the nut is larger than the diameter of the screw, and the refractory mud is arranged at the connection between the nut and the internal threaded hole.

[0013] Optionally, the threaded portion is a stud with an external thread on the circumferential side wall, the stud passes through a support plate, the support plate is located below the bolt, the top end of the stud is inserted into the bottom of the bolt and is threadedly connected to the bolt, and the refractory mud is arranged at the connection between the bottom end of the bolt and the stud.

[0014] In summary, this application has at least the following beneficial technical effects:

[0015] When the tool of the present application is used, the bolt is first threadedly connected to the threaded portion, and then the refractory clay is detachably connected to the connection position of the bolt and the threaded portion to achieve the first anti-carburization; then the end cap is aligned and threaded onto the nut. At this time, the spring presses against the solid ball, and then presses the bolt against the threaded hole to prevent loosening, achieving the second anti-carburization. Double anti-carburization, thereby improving the anti-carburization effect of the threaded hole and increasing the service life of the internal thread to achieve the purpose of increasing the overall service life of the part. At the same time, the tool of the present application is easy to operate and has strong practicality, which can achieve economical, efficient and high-quality processing of the threaded holes of plate parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a threaded anti-carburizing tool in Example 1.

[0017] Figure 2 It is a schematic structural diagram for showing the end cover in Example 1.

[0018] Figure 3 It is a structural schematic diagram for showing the spring and sleeve in Example 1.

[0019] Figure 4 It is a structural diagram for showing a solid ball in Example 1.

[0020] Figure 5 This is a schematic diagram of the overall structure of a threaded anti-carburizing tool in Example 2.

[0021] Figure 6 It is a structural diagram for showing a solid ball in Example 2.

[0022] Figure 7 It is a schematic structural diagram for showing the end cover in Example 2.

[0023] Explanation of the accompanying drawings: 1. Threaded portion; 2. Bolt; 201. Through hole; 202. External thread; 203. V-shaped tapered hole; 204. Hexagonal socket; 205. Round hole; 3. End cover; 301. Second concave cavity; 302. First concave cavity; 303. Spring; 304. Sleeve; 4. Refractory clay; 5. Solid ball; 6. Support plate; 7. Screw. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1-7 This application is described in further detail.

[0025] Example 1

[0026] The embodiment of the present application discloses a threaded portion anti-carburization tool. Figure 1-4 A tool for preventing carburization of threaded parts comprises a threaded part 1, a bolt 2, an end cap 3, and refractory mortar 4. The bolt 2 is threadedly connected to the threaded part 1, and its length is 1 / 4 to 1 / 2 of the length of the thread to be prevented from seepage. The threaded part 1 is an internally threaded hole. The bolt 2 comprises a screw rod and a nut. The screw rod is inserted into the internally threaded hole and threadedly connected to the internally threaded hole. The nut is located outside the internally threaded hole and has a larger diameter than the screw rod. The refractory mortar 4 is applied in a conical shape along the connection between the nut and the internally threaded hole and solidifies.

[0027] The end cap 3 is detachably connected to the bolt 2 and covers the bolt 2 and refractory mortar 4. A spring 303 is fixedly connected to the top wall of the end cap 3. The bolt 2 is provided with a through hole 201 extending from the head to the tail. From top to bottom, the through hole 201 comprises a hexagonal hole 204, a V-shaped tapered hole 203, and a circular hole 205. The minimum diameter of the V-shaped tapered hole 203 is the same as the diameter of the circular hole 205. A solid ball 5 with a diameter between the maximum and minimum diameters of the V-shaped tapered hole 203 is positioned within the V-shaped tapered hole 203, and the spring 303 abuts against the solid ball 5.

[0028] The top of the sidewall surrounding the bolt 2 is provided with external threads 202. The interior of the end cap 3 is divided into a first concave cavity 302 and a second concave cavity 301, which are interconnected. The diameter of the first concave cavity 302 is larger than that of the second concave cavity 301 and is located below the second concave cavity 301. The first concave cavity 302 is located outside the refractory mortar 4. The inner wall of the second concave cavity 301 is threadedly connected to the outer wall of the bolt 2, and a spring 303 is mounted on the top wall of the second concave cavity 301. A sleeve 304 is fixedly connected to the top wall of the end cap 3, and the spring 303 is located inside the sleeve 304.

[0029] Example 2

[0030] The difference between the embodiment of the present application and embodiment 1 is that, Figure 5-7The threaded part 1 is a stud with an external thread on the side wall. The stud passes through a support plate 6. The support plate 6 is located below the bolt 2 and is fixedly connected to the end cover 3 by a screw 7. The top of the stud is inserted into the bottom of the bolt 2 and is threadedly connected to the bolt 2. The refractory mud 4 is set at the connection between the bottom end of the bolt 2 and the stud.

[0031] The steps for using this application are:

[0032] When the threaded portion 1 is an internal threaded hole, that is, embodiment 1:

[0033] 1. Clean the parts, especially the internal threaded holes, and apply anti-carburizing paint to the non-carburized parts. The carburized parts do not need to be painted.

[0034] 2. Clean and dry the bolt 2. For the internal threaded parts of the threaded portion 1, always keep the workpiece horizontally with the threaded hole facing upward for subsequent assembly and use; for the external threaded parts of the threaded portion 1, that is, the stud, place the external thread end of the threaded portion 1 upward.

[0035] 3. Screw bolt 2 into the internal threaded hole until it is fully tightened. Select the appropriate tightening torque according to the strength grade and size of bolt 2. Bolt 2 is made of pure copper. The surface roughness of the V-shaped tapered hole 203 of bolt 2 should be Ra ≤ 0.8.

[0036] Fourth, use refractory mud 4 of appropriate dryness and wetness to seal the nut and the end face of the internal threaded hole in the circumferential direction. The height of the refractory mud 4 is lower than the external thread 202 of the nut head of the bolt 2, and the outermost edge does not exceed the first concave cavity 302 of the end cover 3. The thickness is ≥ 0.5mm;

[0037] 5. Naturally air dry the refractory mud 4 for 8 to 12 hours, and check the sealing and drying conditions;

[0038] 6. Place a solid ball 5 in the V-shaped tapered hole 203 of the bolt 2. The minimum diameter of the V-shaped tapered hole 203 is less than the diameter of the solid ball 5 and less than the maximum diameter of the V-shaped tapered hole 203. The surface roughness of the solid ball 5 should be Ra ≤ 0.8. Bearing steel balls of relevant diameters can be used.

[0039] 7. Screw the end cap 3 into the external thread 202 of the bolt 2, and make the lower end face of the end cap 3 close to the end face of the internal thread hole, and the lower end face of the spring 303 close to the solid ball 5. The spring 303 is a high temperature resistant spring 303 of 1000℃ or above.

[0040] 8. Place the threaded end of the assembled workpiece vertically upwards and install the tire.

[0041] 9. Carry out carburizing treatment according to the process, the carburizing temperature is 880~1000℃, after carburizing, cool to 780~850℃ and keep at an average temperature for 2~4h, then quench in oil or nitrate medium, then temper at 150~250℃, temper for 4~12h according to the cross-sectional size of the part, and air cool after tempering.

[0042] 10. After the workpiece is tempered and air-cooled to room temperature, remove the device in the order of end cover 3, refractory mud 4, and bolt 2.

[0043] 11. Use a wet white cloth to wipe and clean the end face of the screw hole, and then clean the parts as a whole.

[0044] The bolt 2 has a through hole 201 at its center, followed from top to bottom by a hexagonal hole 204, a V-shaped tapered hole 203, and a circular hole 205 of the same diameter as the small end of the V-shaped cavity. The surface roughness of the V-shaped tapered hole 203 and the solid ball 5 is Ra ≤ 0.8, and the radius of the solid ball 5 is less than the diameter of the spring 303 and less than the diameter of the solid ball 5.

[0045] The spring 303 and solid ball 5 in the end cap 3 can be separated or fixedly connected as a single unit. The sleeve 304 outside the spring 303 does not contact the inner wall of the V-shaped tapered hole 203. After installation, the combined force of the spring 303's elastic force, the weight of the solid ball 5's gravity, and the pressure within the heat treatment furnace ensures a constant, tight fit between the solid ball 5 and the V-shaped cavity. When the air in the internally threaded hole expands, the resulting thrust pushes the solid ball 5 upward, compressing the spring 303 and expelling the air. When the ratio (spring 303's elastic force + weight of the solid ball 5 + pressure within the heat treatment furnace) ≥ the air pressure thrust within the internally threaded hole, the internally threaded hole is sealed.

[0046] The multiple sealing mechanisms of the bolt 2, refractory mortar 4, and end cap 3 ensure that the threaded hole is protected from carburization. Furthermore, the end cap 3 provides a certain degree of isolation from the refractory mortar 4, preventing contamination of the quenching fluid during part quenching. Furthermore, the refractory mortar 4 cannot be reused; a new refractory mortar 4 must be used each time to seal the end face gap. The copper bolt 2 does not deform during carburizing and quenching like steel does, making it easy to disassemble and reuse. Furthermore, copper has a low hardness at high temperatures and does not damage the threads of the internally threaded hole.

[0047] The above device and method can also be used for preventing threaded holes from leaking during nitriding.

[0048] When the threaded portion 1 is an external thread on a stud, that is, embodiment 2:

[0049] (All steps refer to the above threaded portion 1 is an internal threaded hole, and the corresponding internal threaded hole is a stud with external threads on the side wall)

[0050] The first and second steps are the same as above.

[0051] In the third step, before tightening the bolts 2, heat the area of ​​the support plate 6 where the threaded portion 1 penetrates to 100-200°C, insert the studs for shrink-fitting, and ensure that the support plate 6 is horizontal. Assembly is then performed according to steps 3 through 7. In the fourth step, the refractory mortar 4 is filled to a level lower than the external threads of the studs on the workpiece that require carburization prevention. After installing the end cap 3 and support plate 6 according to step 7, screws 7 are used to tighten the support plate 6 to the end cap 3.

[0052] Carry out workpiece tire, heat treatment, device removal and cleaning subsequently according to above-mentioned 8th to 11. Wherein before the 10th step begins, take off screw 7 earlier, then carry out remaining parts removal according to step 10 again, remove support plate at last.

[0053] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A threaded part anti-carburization tool, characterized by: It comprises a threaded portion (1), a bolt (2) and refractory mud (4), wherein the bolt (2) is threadedly connected to the threaded portion (1), and the refractory mud (4) is detachably connected to the connection position between the bolt (2) and the threaded portion (1); It also includes an end cover (3), which is detachably connected to the bolt (2) and covers the bolt (2) and the refractory mud (4), and a spring (303) is fixedly connected to the top wall of the end cover (3).

2. A threaded portion anti-carburization tool according to claim 1, characterized in that: The bolt (2) is provided with a through hole (201) passing through the head and tail, and the through hole (201) is composed of a hexagonal hole (204), a V-shaped tapered hole (203) and a round hole (205) from top to bottom. The minimum end diameter of the V-shaped tapered hole (203) is the same as the diameter of the round hole. A solid ball (5) having a diameter between the maximum end diameter and the minimum end diameter of the V-shaped tapered hole (203) is provided in the V-shaped tapered hole (203), and the spring (303) abuts against the solid ball (5).

3. A threaded portion anti-carburization tool according to claim 2, characterized in that: The top of the peripheral side wall of the bolt (2) is provided with an external thread (202); the interior of the end cover (3) is divided into a first concave cavity (302) and a second concave cavity (301) which are interconnected, the diameter of the first concave cavity (302) being larger than the diameter of the second concave cavity (301) and being located below the second concave cavity (301), and the first concave cavity (302) being covered outside the refractory mud (4); The inner side wall of the second concave cavity (301) is connected to the external thread (202) of the bolt (2), and the spring (303) is arranged on the top wall of the second concave cavity (301).

4. A threaded portion anti-carburization tool according to claim 1, characterized in that: The refractory mud (4) is laid in a conical shape along the connection position between the nut and the threaded portion (1) and solidified.

5. A threaded portion anti-carburization tool according to claim 2, characterized in that: A sleeve (304) is fixedly connected to the top wall inside the end cover (3), and the spring (303) is located inside the sleeve (304).

6. A threaded portion anti-carburization tool according to claim 1, characterized in that: The threaded portion (1) is an internal threaded hole, the bolt (2) includes a screw and a nut, the screw is inserted into the internal threaded hole and is threadedly connected to the internal threaded hole, the nut is located outside the internal threaded hole and the diameter of the nut is larger than the diameter of the screw, and the refractory mud (4) is arranged at the connection between the nut and the internal threaded hole.

7. The threaded portion anti-carburization tool according to claim 1, characterized in that: The threaded portion (1) is a stud with an external thread on the circumferential side wall, the stud passes through a support plate (6), the support plate (6) is located below the bolt (2), the top end of the stud is inserted into the bottom of the bolt (2) and is connected to the bolt thread, and the refractory mud (4) is arranged at the connection between the bottom end of the bolt (2) and the stud.

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