CN116638258A - Repair process of inner thread of super-large diameter shield cutter head under normal pressure tool changer and cutter barrel mounting seat - Google Patents

Abstract

The invention relates to an internal thread repairing process for an ultra-large diameter shield cutterhead normal-pressure tool changing tool cylinder mounting seat, which comprises the following steps: machining the damaged screw hole to form a reaming hole, and tapping the reaming hole by adopting a screw tap; screwing the thread sleeve into the reaming by adopting a special tool; the reaming is welded with the outer surface of the thread bush; polishing to enable the end part of the thread sleeve to be flush with the tool apron frame. The beneficial effects of the invention are as follows: the thread sleeve is pre-machined through a numerical control machine tool and only needs to be screwed into the reaming, so that the influence of external factors is small, the downtime of the shield machine is greatly reduced, and the construction period is saved; because the internal thread of the thread sleeve is the same as the original thread of the damaged screw hole in size, the effect of replacing the damaged screw hole is achieved, and the matching use of the original components of the tool apron is ensured.

Description

Repair process of internal thread of super-large diameter shield cutter head under atmospheric pressure tool changer

technical field

The invention belongs to the technical field of shield tunneling, and in particular relates to a process for repairing internal threads of a super-large-diameter shield cutter head under normal pressure for a cutter barrel mounting seat.

Background technique

In the construction process of modern urban subways and highway tunnels, the shield tunneling method is widely used. The shield tunneling method has the advantages of less disturbance to the bottom layer, fast construction speed, and high degree of mechanization. However, for some special engineering situations, due to the complex soil layer, it is easy to cause abnormal wear on the shield cutter, and the cutter needs to be replaced frequently, which is easy to cause The thread slippage of the tool holder will affect the operation of the shield machine.

At present, for the problem of slippage in the screw hole of the shield tool holder, the overall replacement plan is generally adopted, but the overall replacement price is high, which affects the overall cost control of the project, and the purchase and installation process is long, which has a great impact on the construction period.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and to provide a process for repairing the inner thread of the mounting seat of the cutter barrel of the ultra-large diameter shield cutter under normal pressure.

This super-large-diameter shield cutterhead repair process for the internal thread of the cutter barrel mounting seat under normal pressure includes a tool holder frame and a threaded sleeve. including damaged screw holes;

The threaded sleeve is hollow, the outer surface of the threaded sleeve is provided with the external thread of the threaded sleeve, and the inner surface of the threaded sleeve is provided with the internal thread of the threaded sleeve; the damaged screw hole is provided with a reamed hole, and the reamed hole is provided with a thread matching the external thread of the threaded sleeve; The threaded sleeve is set in the reaming hole through the external thread of the threaded sleeve, and the internal thread of the threaded sleeve is the same as the thread of the original screw hole of the tool seat;

There are also special tooling for screwing the threaded sleeve into the counterbore.

As a preference: the special tooling includes bolts and auxiliary nuts, the bolts are matched with the internal thread of the threaded sleeve, and the auxiliary nut is fixed on the threaded section of the bolt; when the threaded sleeve is screwed into the reaming hole, the front end of the bolt extends into the threaded sleeve, and the threaded sleeve The end interferes with the auxiliary nut.

As a preference: the entrance end of the reamed hole of the damaged screw hole is provided with a bevel, and the angle of the bevel is 40-60°; the reamed hole and the threaded sleeve are welded and connected at the bevel.

Preferably: the end of the threaded sleeve is flush with the tool seat frame.

As a preference: the scope of reaming includes the damaged screw hole, and the axes of the reamed hole and the damaged screw hole are the same, and the size of the reamed hole is larger than the size of the damaged screw hole.

The construction method of the super-large-diameter shield cutter head under normal pressure and the internal thread repair process of the cutter barrel mounting seat includes the following steps:

Step 1. Reaming construction: process the damaged screw hole to form a reaming hole, use a tap to tap the reaming hole, and process the groove at the entrance of the reaming hole;

Step 2. Install the threaded sleeve: Use special tooling to screw the threaded sleeve into the reaming hole, first screw the front end of the bolt into the threaded sleeve until the end of the threaded sleeve is in contact with the auxiliary nut, and then screw the threaded sleeve into the reaming hole through the bolt;

Step 3. Welding reinforcement: Welding is carried out at the groove, and the reaming hole is welded to the outer surface of the threaded sleeve;

Step 4. Grinding: Grind the part of the threaded sleeve that is higher than the frame of the tool holder, so that the end of the threaded sleeve is flush with the frame of the tool holder.

Preferably, before the threaded sleeve is installed, thread glue is applied to the front end of the threaded sleeve; after the threaded sleeve is screwed into the reaming hole, the internal thread of the threaded sleeve is tapped for correction.

The beneficial effects of the present invention are:

1) Compared with the overall replacement of the tool holder frame, the tool holder internal thread repair method has low material and labor costs, and has better economic benefits.

2) The construction time of this method for repairing the internal thread of the tool seat is short. The thread sleeve is pre-processed by the CNC machine tool, and only needs to be screwed into the reaming hole. It is less affected by external factors, greatly reducing the downtime of the shield machine and saving the construction period.

3) After repairing the damaged screw hole of the tool holder, since the internal thread of the threaded sleeve is the same as the original thread size of the damaged screw hole, the effect of replacing the damaged screw hole is achieved, ensuring the matching and use of the original components of the tool holder.

Description of drawings

Figure 1 is a diagram of the shield tool seat;

Fig. 2 is thread cover figure;

Fig. 3 is a schematic diagram of the internal and external threads of the threaded sleeve;

Figure 4 is a schematic diagram of threaded sleeve installation.

Explanation of reference signs: knife seat frame 1, original screw hole 2 of knife seat, threaded sleeve 3, external thread 31 of threaded sleeve, internal thread 32 of threaded sleeve, bolt 4, auxiliary nut 5.

Detailed ways

The present invention will be further described below in conjunction with the examples. The description of the following examples is provided only to aid the understanding of the present invention. It should be pointed out that for those skilled in the art, some modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Embodiment one

As an example, as shown in Figures 1 to 4, this super-large-diameter shield cutter head atmospheric pressure tool changer barrel mounting seat internal thread repair process includes a tool seat frame 1 and a threaded sleeve 3, the tool seat frame 1 The original screw hole 2 of the knife seat is provided in the upper ring direction, and the original screw hole 2 of the knife seat includes the damaged screw hole;

As shown in FIG. 2 and FIG. 3 , the threaded sleeve 3 is hollow, the outer surface of the threaded sleeve 3 is provided with a threaded sleeve external thread 31 , and the inner surface of the threaded sleeve 3 is provided with a threaded sleeve internal thread 32 .

The damaged screw hole is treated to form a reamed hole. The scope of reaming includes the damaged screw hole, and the axis of the reamed hole is the same as that of the damaged screw hole. The size of the reamed hole is larger than the size of the damaged screw hole. Thread sleeve external thread 31 matches the thread. The entrance end of the reaming of the damaged screw hole is provided with a bevel, and the angle of the bevel is 40-60°.

The threaded sleeve 3 is arranged in the reaming hole through the threaded sleeve external thread 31, and the reaming and the threaded sleeve 3 are welded at the bevel, and the end of the threaded sleeve 3 is flush with the tool holder frame 1.

Thread sleeve internal thread 32 is identical with the screw thread of original screw hole 2 of knife seat; After thread sleeve 3 is screwed in the reaming, can completely replace original damaged screw hole.

As shown in Figure 4, there is also a special tool for screwing the threaded sleeve 3 into the reaming hole. The special tooling includes a bolt 4 and an auxiliary nut 5, the bolt 4 is matched with the internal thread 32 of the threaded sleeve, and the auxiliary nut 5 is fixed on the threaded section of the bolt 4; when the threaded sleeve 3 is screwed into the reaming hole, the front end of the bolt 4 extends into the thread Inside the sleeve 3, the end of the threaded sleeve 3 is in conflict with the auxiliary nut 5, and the auxiliary nut 5 acts as a limiter. At this time, rotating the bolt 4 can make the threaded sleeve 3 rotate synchronously and be screwed into the reaming hole.

Embodiment two

As another embodiment, the construction method of the internal thread repair process of the super-large-diameter shield cutterhead in the first embodiment under normal pressure tool change barrel mounting seat includes the following steps:

Step 1. Reaming construction: first install a magnetic drill at the corresponding position of the damaged screw hole. In order to ensure the safety of construction personnel, the power socket used by the magnetic drill must match the power plug of the magnetic drill, and a leakage protector must be installed on the side where the power is introduced. After the magnetic drill is safely adsorbed on the workpiece, fine-tune the installation position of the magnetic drill to ensure that the concentricity of the magnetic drill axis and the damaged screw hole is ≤0.2mm, and the verticality is ≤0.2mm, and then the damaged screw hole is cleaned. The parameter of damaged screw hole in the embodiment is Use a magnetic drill to enlarge this damaged screw hole to /> To form a reamed hole, in order to ensure the quality of the drilled hole, cutting oil must be used during the drilling process, and aqueous solution must not be used; after the reamed hole is processed, the tap is used to tap the reamed hole to form an M36*2 thread. Insert the nose cone so that the centerline of the tap coincides with the centerline of the drilled hole. Rotate both hands evenly and apply a little pressure to make the tap enter the knife. After entering the knife, there is no need to apply additional pressure; each time the tap is rotated, it is reversed about 45° to cut off the chips to avoid blockage; in order to facilitate subsequent welding operations, mechanical methods are used at the entrance of the reaming hole Processing groove, groove angle is 40 ~ 60 °.

Step 2. Install the threaded sleeve: Prefabricate the threaded sleeve 3 with high-strength chrome-molybdenum steel hot-rolled bar or forged billet. After quenching-tempering-normalizing heat treatment, the hardness of the threaded sleeve 3 is HRC42-45, which is specially used for CNC machine tool processing The parameter of the threaded sleeve external thread 31 of the threaded sleeve 3 is M36*2mm, and the threaded sleeve internal thread 32 is M30*3.5mm; before installing the threaded sleeve 3, thoroughly clean the reamed and tapped internal threaded holes and the spare threaded sleeve, Remove residue and oil stains, apply Loctite 234 thread glue on the front end of the threaded sleeve before installing the threaded sleeve; use special tooling to screw the threaded sleeve 3 into the reaming hole, first screw the front end of the bolt 4 into the threaded sleeve 3 until the threaded sleeve 3 The end is in conflict with the auxiliary nut 5, and then the threaded sleeve 3 is screwed into the reaming hole through the bolt 4, and the torque is 320N/M; after the threaded sleeve 3 is screwed into the reaming hole, the internal thread 32 of the threaded sleeve is tapped to correct it.

Step 3. Welding reinforcement: Welding at the groove, welding the reaming hole and the outer surface of the threaded sleeve 3; using chrome-molybdenum steel welding wire TIG to weld the outside of the threaded sleeve 3 and the groove, and after the arc is ignited, it must be welded at the beginning of the weldment. Preheat the place for 3 to 5 seconds, and start wire feeding after the molten pool is formed; when welding, the angle of the welding wire torch should be appropriate, and the welding wire should be fed evenly to ensure that the weld seam is full and cannot damage the internal threads of the threaded sleeve, and color the weld seam For penetrant flaw detection, the oxide skin, oil stains and other stains on the flaw detection area and its adjacent area within 25 mm that affect the penetration of the penetrant should be thoroughly removed to ensure the flaw detection effect.

Step 4. Grinding: After the welding quality inspection is qualified, manually polish the part of the threaded sleeve 3 that is higher than the tool holder frame 1. The surface can be polished with an angle grinder using a coarse grinding wheel surface to avoid welding scars, and then use the louver for details. Grinding; ensure that the flatness is ≤0.05mm, the roughness is ≤Ra1.6, and ensure the thread quality so that the end of the threaded sleeve 3 is flush with the tool holder frame 1; finally, use an M30 tap to tap the repaired internal thread hole.

If the original screw hole 2 of the tool holder is of other sizes, the size of the external thread 31 of the threaded sleeve can be determined by oneself under the condition of ensuring the strength of the threaded sleeve 3, and the size of the internal thread 32 of the threaded sleeve can be matched with the original screw hole 2 of the tool holder.

Claims (7)

1. The process for repairing the internal threads of the mounting seat of the normal-pressure tool changing cylinder of the oversized-diameter shield cutterhead is characterized by comprising the following steps of: the tool apron comprises a tool apron frame (1) and a thread sleeve (3), wherein the tool apron frame (1) is provided with an original screw hole (2) of the tool apron in a circumferential direction, and the original screw hole (2) of the tool apron comprises a damaged screw hole;

the thread sleeve (3) is hollow, the outer surface of the thread sleeve (3) is provided with thread sleeve external threads (31), and the inner surface of the thread sleeve (3) is provided with thread sleeve internal threads (32); a reaming is arranged at the damaged screw hole, and threads matched with the external threads (31) of the thread sleeve are arranged in the reaming; the thread sleeve (3) is arranged in the reaming through a thread sleeve external thread (31), and a thread sleeve internal thread (32) is the same as the thread of the original screw hole (2) of the tool apron;

there is also a special tooling for screwing the threaded sleeve (3) into the counterbore.

2. The process for repairing the internal threads of the mounting seat of the normal-pressure tool changing cylinder of the oversized-diameter shield cutter head, disclosed by claim 1, is characterized in that: the special tool comprises a bolt (4) and an auxiliary nut (5), wherein the bolt (4) is matched with an internal thread (32) of a thread sleeve, and the auxiliary nut (5) is fixed on a thread section of the bolt (4); when the thread sleeve (3) is screwed into the reaming, the front end of the bolt (4) stretches into the thread sleeve (3), and the end part of the thread sleeve (3) is abutted against the auxiliary nut (5).

3. The process for repairing the internal threads of the mounting seat of the normal-pressure tool changing cylinder of the oversized-diameter shield cutter head, disclosed by claim 1, is characterized in that: the reaming inlet end of the damaged screw hole is provided with a bevel, and the angle of the bevel is 40-60 degrees; the reaming is welded with the thread sleeve (3) at the groove.

4. The process for repairing the internal threads of the mounting seat of the normal-pressure tool changing cylinder of the oversized-diameter shield cutter head, disclosed by claim 1, is characterized in that: the end of the thread sleeve (3) is flush with the tool apron frame (1).

5. The process for repairing the internal threads of the mounting seat of the normal-pressure tool changing cylinder of the oversized-diameter shield cutter head, disclosed by claim 1, is characterized in that: the range of the reaming includes the damaged screw hole, and the reaming is the same as the shaft of the damaged screw hole, and the reaming size is larger than the size of the damaged screw hole.

6. The construction method of the ultra-large diameter shield cutter head normal pressure tool changing tool cylinder mounting seat internal thread repairing process according to any one of claims 1 to 5, which is characterized by comprising the following steps:

step one, reaming construction: machining the damaged screw hole to form a reaming, tapping the reaming by adopting a screw tap, and machining a groove at the reaming inlet;

step two, installing a threaded sleeve: screwing the thread sleeve (3) into the reaming by adopting a special tool, screwing the front end of the bolt (4) into the thread sleeve (3) until the end part of the thread sleeve (3) is abutted against the bolt (4), and screwing the thread sleeve (3) into the reaming by the bolt (4);

step three, welding and reinforcing: welding at the groove, and welding and connecting the reaming with the outer surface of the thread sleeve (3);

step four, polishing: and polishing the part of the threaded sleeve (3) higher than the tool apron frame (1) to enable the end part of the threaded sleeve (3) to be flush with the tool apron frame (1).

7. The construction method of the ultra-large diameter shield cutterhead normal pressure tool changing tool cylinder mounting seat internal thread repairing process according to claim 5 is characterized in that before the thread bush (3) is mounted, thread glue is smeared at the front end of the thread bush (3); after the thread sleeve (3) is screwed into the reaming, tapping correction is carried out on the internal thread (32) of the thread sleeve through a tap.