Apparatus and method for marking a group of holes with localized low stress marks

Abstract

The application discloses a device and a method for marking a tube hole group with local low stress, which comprises a steel stamp, a positioning plate, a positioning pin and a limiting plate. The positioning plate is provided with a positioning pin hole and a limiting plate hole. The positioning pin is inserted into the positioning pin hole on the positioning plate and then into a tube hole on a tube plate to be marked. The limiting plate is placed in the limiting plate hole. By adjusting the position of a character matrix station on the limiting plate, low stress marking is completed on the tube plate by using the steel stamp. The device has a simple structure. When low stress marking is performed, the marking range can be strictly controlled within the position to be marked. The device has high reliability, fast low stress marking speed, high efficiency, unified and correct marked position, safety in use, low possibility of accidents caused by unqualified low stress marking and is suitable for marking operations of tube plates of different specifications. The device provides a new idea for marking operations in narrow areas in various fields.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pressure vessels and steam generators, in particular to the technical field of steel stamp marking of pressure vessels and steam generators. BACKGROUND

[0002] A steel stamp is a seal composed of two stamping molds of upper and lower yin and yang made of steel plate, usually sealed on special text or photos, without color, only convex or concave text, numbers and symbols. In steel enterprises, it is used for marking finished plate or bar. With the development of society and the progress of science and technology, steel stamp is widely used in the field of pressure vessels and nuclear power steam generators for marking heat exchanger tube sheet information.

[0003] Before the tube is inserted, the relevant information of the tube hole needs to be marked on the tube sheet, that is, steel stamp marking or marking is needed. However, during marking, the stress level of the heat exchanger tube sheet in the field of pressure vessels and nuclear power steam generators is low, and other marking methods such as laser marking may cause uncertain damage to the tube sheet itself, which may further cause major safety accidents. Therefore, the marking information must be marked by low-stress steel stamping to reduce the damage to the tube sheet during marking.

[0004] The main difficulties in marking the heat exchanger tube sheet in the field of pressure vessels and nuclear power steam generators are as follows:

[0005] (1) During marking, if high-stress steel stamping or obvious steel stamp marks are produced on the tube sheet, the residual stress is likely to cause uneven stress on the internal structure of the tube sheet, which may lead to deformation, delayed cracking, fracture, reduced surface strength and corrosion resistance of the tube sheet, and may cause quality accidents such as boiler explosion;

[0006] (2) The heat exchanger tube sheet in the field of pressure vessels and nuclear power steam generators has a large number of densely distributed tube holes, resulting in a very small area available for marking on the tube sheet, and no physical boundary for reference;

[0007] (3) During marking, it is required that there be no marks within a certain range around the tube hole (e.g. within 22mm of the tube hole diameter), i.e. no marking is allowed;

[0008] (4) The low-stress marking method itself is relatively rough and is likely to cause out-of-bound marking.

[0009] The above reasons make it very difficult to mark the heat exchanger tube sheet in the field of pressure vessels and nuclear power steam generators in a narrow space with low stress, and it is difficult to ensure product quality.

[0010] In view of the above reasons, it is urgent to study the steel stamp marking method on the tube plate of the heat exchanger of the pressure vessel and nuclear power steam generator field, and to explore a kind of efficient, feasible and low stress marking method which can ensure the smooth completion of marking. SUMMARY

[0011] In order to overcome the above problems, the present inventors have made intensive research and developed a device and method for low stress marking with limitation in tube hole group, which comprises a steel stamp, a positioning plate, a positioning pin and a limiting plate. The positioning plate is provided with a positioning pin hole and a limiting plate hole. The positioning pin is inserted into the positioning pin hole on the positioning plate and then into the tube hole on the tube plate to be marked. The limiting plate is placed in the limiting plate hole. By adjusting the position of the letter die station on the limiting plate, low stress marking is completed on the tube plate by using the steel stamp. The device has a simple structure. When low stress marking is performed, the marking range can be strictly controlled within the to-be-marked position. The device has high reliability, fast low stress marking speed, high efficiency, uniform and correct marked position, safety in use, low possibility of accidents caused by unqualified low stress marking, and is suitable for marking operation of different specifications of tube plates. It also provides a new idea for marking operation in narrow areas in various fields, thereby achieving the present invention.

[0012] Specifically, the present application aims to provide the following aspects:

[0013] In a first aspect, a device for low stress marking with limitation in tube hole group is provided, which comprises a steel stamp and a limiting plate. One end of the steel stamp is a letter die end, and the other end is a handle end. The limiting plate is provided with a letter die station which can be clamped with the letter die end of the steel stamp.

[0014] Preferably, the shape of the limiting plate is square.

[0015] Preferably, the shape of the letter die station on the limiting plate and the shape of the letter die end of the steel stamp are both square.

[0016] Preferably, the limiting plate is selected from a middle limiting plate and / or a four-corner limiting plate. The right upper corner of the middle part of the middle limiting plate is provided with a letter die station, and the right upper corner of the four-corner limiting plate is provided with a letter die station.

[0017] By adjusting the embedding mode of the middle limiting plate and / or the four-corner limiting plate, the position of the letter die station on the to-be-marked position can be adjusted. The letter die end of the steel stamp is inserted into the letter die station, and the handle end of the steel stamp is hammered to complete low stress marking.

[0018] Preferably, the device further comprises a positioning plate and a positioning pin for fixing the limiting plate.

[0019] The positioning plate is provided with a positioning pin hole and a limiting plate hole, the positioning pin is inserted into the positioning pin hole on the positioning plate, then the limiting plate is placed at the limiting plate hole, and the low stress marking is completed on the tube plate by using the steel stamp.

[0020] In another aspect, a method for low stress marking by using the device of the first aspect is provided, which comprises: adjusting the embedding mode of the limiting plate to adjust the position of the type die station on the to-be-marked position, inserting the type die end of the steel stamp into the type die station, and hammering the handle end of the steel stamp to realize low stress marking on the tube plate.

[0021] The limiting plate is selected from an intermediate limiting plate and / or a four-corner limiting plate, wherein the four-corner limiting plate is used for low stress marking of the four-corner part of the to-be-marked position, and the intermediate limiting plate is used for low stress marking of the middle part of the to-be-marked position.

[0022] The four-corner limiting plate and / or the intermediate limiting plate are embedded into the positioning plate by adjusting the embedding angle through flipping or rotating, and are used for low stress marking of the required part of the to-be-marked position.

[0023] The present application has the following beneficial effects:

[0024] (1) The low stress marking device with local limitation provided by the present application has simple structure, and is convenient to install and use, thereby improving the marking efficiency for the heat exchanger tube plate in the field of pressure vessels and nuclear power steam generators.

[0025] (2) The low stress marking device with local limitation provided by the present application has ingenious limiting plate structure, and can strictly control the marking range within the to-be-marked position during low stress marking, so that the product qualified rate reaches 100%, and the possibility of accidents caused by unqualified low stress marking is reduced.

[0026] (3) The low stress marking device with local limitation provided by the present application can select appropriate type die and limiting plate according to the to-be-marked position, and has strong practicability and strong universality.

[0027] (4) The method for low stress marking by using the low stress marking device with local limitation provided by the present application has strong reliability, fast low stress marking speed, high efficiency, correct and unified marked position, safety in use, and is suitable for marking operation of different specifications of tube plates.

[0028] (5) The method for low stress marking by using the low stress marking device with local limitation provided by the present application is simple, and provides a new idea for marking operation in narrow areas in various fields. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0030] Figure 2 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown. Figure 1 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0031] Figure 3 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0032] Figure 4 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0033] Figure 5 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0034] Figure 6 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0035] Figure 7 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0036] Figure 8 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0037] Figure 9 Structure schematic diagram of low stress marking device with limitation in tube hole group according to a preferred embodiment of the present application is shown.

[0038] Explanation of reference numerals:

[0039] 1-steel stamp;

[0040] 2-positioning plate;

[0041] 2-1-positioning pin hole;

[0042] 2-2-limiting plate hole;

[0043] 2-3-limiting area;

[0044] 2-4-hexagonal positioning area;

[0045] 3-positioning pin;

[0046] 4-limiting plate;

[0047] 4-1-intermediate limiting plate;

[0048] 4-2-quadrilateral limiting plate;

[0049] 5-tube plate;

[0050] 6-The location to be marked;

[0051] 7-Pipe hole. Detailed Implementation

[0052] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0053] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0054] On the one hand, the present invention aims to provide a device for a limited low-stress mark in a group of tube holes. The device includes a steel stamp 1 and a limiting plate 4. The limiting plate 4 is provided with a character mold station, that is, the position of the notch on the limiting plate 4, which can engage with one end of the steel stamp 1.

[0055] According to the present invention, the steel stamp 1 is used to complete low-stress marking. One end is a character mold end, on which a character mold is engraved, which can engage with a character mold station on the limiting plate 4. The other end is a handle end. In use, the character mold end of the steel stamp 1 is inserted into the character mold station of the limiting plate 4, and the handle end of the steel stamp 1 is hammered to complete the low-stress marking.

[0056] According to the present invention, since the heat exchanger tube sheet 5 in the field of pressure vessels and nuclear power steam generators has densely distributed tube holes, and it is required that low-stress markings cannot be performed within a certain range around the tube holes, the size of the marking position 6 can be understood as square. The shape and size of the limiting plate 4 cannot exceed the range of the marking position 6, and its shape (including the lettering station) can be any one of square, circle, trapezoid, or rhombus, preferably square. Figures 1-4 As shown.

[0057] Among them, the square limiting plate 4 is easy to process, and the size of the position to be marked 6 is small, so the square limiting plate 4 can maximize the use of space.

[0058] Furthermore, the end of the stamp 1 typeface is preferably square to provide the maximum space for the typeface, and the typeface station on the limiting plate 4 that engages with it is also square in shape.

[0059] Furthermore, one end of the stamp 1 is the character mold end, and the other end is the handle end. When marking under low stress, the handle end is hammered to stamp the character mold on the tube plate 5.

[0060] The handle end of the seal 1 is preferably a square or a cylinder, preferably a cylinder, which is convenient for holding and using; the character mold end is preferably a square, and the length is greater than the thickness of the limiting plate 4. Preferably, the length of the handle end is 2-5 times the length of the character mold end.

[0061] The thickness of the limiting plate 4 is 2-10 mm, preferably 4-6 mm, for example, 5 mm.

[0062] The present inventors found that the to-be-marked position 6 on the tube plate 5 can be evenly divided into an even number of parts, for example, 2, 4, 6, 8, 10, etc., according to the size, the limiting plate 4 is set to different structures according to the size, the position of the character mold station on the limiting plate 4 is adjusted by replacing the limiting plate 4 or rotating the limiting plate 4 with different structures, which is convenient and fast, and the product qualification rate is as high as 100%. For example, the to-be-marked position 6 is evenly divided into 4 parts according to the size, a character mold station is arranged at the upper right corner of the limiting plate 4, and the size of the character mold station occupies 1 / 4 of the total area of the limiting plate 4 (including the character mold station), and the structure is as shown in Figure 4 The character mold end of the seal 1 is clamped at the character mold station position of the upper right corner of the four-corner limiting plate 4-2, and the low-stress marking of the upper right corner of the to-be-marked position 6 is completed; then, the four-corner limiting plate 4-2 is mirror image flipped, the character mold end of the seal 1 is clamped at the character mold station, and the low-stress marking of the upper left corner of the to-be-marked position 6 is completed; similarly, the four-corner limiting plate 4-2 is flipped up and down, the character mold end of the seal 1 is clamped at the character mold station, and the low-stress marking of the lower right corner of the to-be-marked position 6 is completed; the four-corner limiting plate 4-2 is rotated by 180° and placed, the character mold end of the seal 1 is clamped at the character mold station, and the low-stress marking of the lower left corner of the to-be-marked position 6 is completed.

[0063] In a typical way, when the heat exchanger tube plate 5 in the field of pressure vessels and nuclear power steam generators is low-stress marked, there are dense tube holes on the tube plate 5, and it is required that low-stress marking cannot be performed within a certain range around the tube hole, for example, within a range of 22 mm in diameter of the tube hole, and the size of the to-be-marked position 6 is about 12.2 mm x 8.4 mm of a rectangle, at this time, it can be divided into 8 parts, that is, 4 rows x 2 columns, at this time, the limiting plate 4 is set to two kinds of middle limiting plate 4-1 and four-corner limiting plate 4-2, as shown in Figure 5 .

[0064] The middle part of the middle limiting plate 4-1 is provided with a character mold station at the upper right corner, and the size of the character mold station occupies 1 / 8 of the total area of the middle limiting plate 4-1 (including the character mold station), and the upper right corner of the four-corner limiting plate 4-2 is provided with a character mold station, and the size of the character mold station occupies 1 / 8 of the total area of the four-corner limiting plate 4-2 (including the character mold station), as shown in Figures 3-4 .

[0065] In use, low-stress marking is achieved by adjusting the positions of the middle limiting plate 4-1 and the four corner limiting plates 4-2. Specifically: Place the four corner limiting plates 4-2 on the position to be marked 6, and engage the steel stamp 1 character mold end with the upper right corner of the four corner limiting plates 4-2 to complete the low-stress marking at the upper right corner of the position to be marked 6; then, mirror-flip, flip up and down, and rotate 180° on the four corner limiting plates 4-2 respectively to complete the low-stress marking at the upper left, lower right, and lower left corners of the position to be marked 6; place the middle limiting plate 4-1 on the position to be marked 6, and engage the steel stamp 1 character mold end with the upper right corner of its middle part to complete the low-stress marking at the upper right middle corner of the position to be marked 6; then, mirror-flip, flip up and down, and rotate 180° on the middle limiting plate 4-1 respectively to complete the low-stress marking at the upper left middle, lower right middle, and lower left middle corners of the position to be marked 6.

[0066] According to a preferred embodiment, the device includes a steel stamp 1, a positioning plate 2, a positioning pin 3, and a limiting plate 4. The positioning plate 2 is provided with a positioning pin hole 2-1 and a limiting plate hole 2-2. By inserting the positioning pin 3 into the positioning pin hole 2-1 on the positioning plate 2, it is fixed to the tube hole 7 on the tube plate 5 to be marked. The limiting plate 4 is placed in the limiting plate hole 2-2, and the steel stamp 1 is used to complete the low-stress marking on the tube plate 5.

[0067] In this invention, the materials of the positioning plate 2 and the limiting plate 4 are the same as or similar to the materials of the tube plate 5, which are iron-free stainless steel, preferably nickel-based alloys, such as nickel-zinc alloy, nickel-titanium alloy, nickel-chromium alloy, etc.

[0068] In practice, the material of tube sheet 5 is mostly nickel-chromium alloy. Chromium in tube sheet 5 is prone to intergranular corrosion with iron, which leads to uneven internal structure and, in severe cases, surface cracks. These cracks can further generate fissures, resulting in accidents such as boiler explosions. Therefore, the materials of positioning plate 2 and limiting plate 4 must contain stable elements and must not contain iron to reduce the tendency to form intergranular corrosion.

[0069] In this invention, the hardness of the material of the positioning pin 3 is between that of the tube plate 5 and the steel stamp 1, and is preferably selected from any one or more of polytetrafluoroethylene, perfluoroethylene propylene, polyethylene terephthalate, polyethylene, and polypropylene, and more preferably polytetrafluoroethylene.

[0070] Among them, the aforementioned positioning pin 3 material has moderate hardness, and most importantly, it will not scratch the tube sheet 5. In particular, polytetrafluoroethylene is known as the "King of Plastics". It is widely available, corrosion resistant, has low surface tension, excellent anti-aging resistance, does not adhere to any substances, has a low coefficient of friction, and is easy to clean, making it an ideal material for preparing positioning pin 3.

[0071] In the present application, the seal 1 is made of common stainless steel material, and any commercially available stainless steel material can be used.

[0072] According to the present application, the positioning pin 3 comprises a positioning cap and a positioning rod, the positioning rod is engaged with the positioning pin hole 2-1 on the positioning plate 2, and the shape of the positioning rod is any one or several of a circle, an ellipse, a square, and preferably a circle for easy operation and processing. Further preferably, the end of the positioning rod is tapered to facilitate insertion and removal, as shown in Figures 1-2

[0073] According to the present application, the positioning plate 2 is provided with 2-12 positioning pin holes 2-1, the positions of the positioning pin holes 2-1 correspond to the positions of the tube holes on the tube plate 5, preferably 3-9 positioning pin holes 2-1 are provided, and more preferably 6 positioning pin holes 2-1 are provided. When the positioning pin 3 is inserted into the positioning pin hole 2-1 to fix the positioning plate 2, only the positioning plate 2 needs to be fixed, and the positioning pin 3 does not need to be inserted into each positioning pin hole 2-1, for example, when the positioning plate 2 is provided with 6 positioning pin holes 2-1, one positioning pin 3 is inserted into every other positioning pin hole 2-1, as shown in Figures 1-2

[0074] Among them, the positioning pin hole 2-1 on the positioning plate 2 is not larger than the tube hole on the tube plate 5, preferably the diameter of the positioning pin hole 2-1 on the positioning plate 2 is equal to the diameter of the tube hole on the tube plate 5. At this time, the positioning pin 3 is inserted into the positioning pin hole 2-1, and the positioning plate 2 is fixed and installed on the tube plate 5 more firmly.

[0075] According to the present application, the limiting plate hole 2-2 on the positioning plate 2 is engaged with the limiting plate 4 to prevent displacement of the limiting plate 4 during the low-stress marking process.

[0076] Among them, the shape of the positioning plate 2 has no special requirements, mainly the positioning pin hole 2-1 provided therein corresponds to the position of the tube hole on the tube plate 5, which can be square, tapered, circular, etc., and preferably square for easy use and storage.

[0077] On the other hand, the present application aims to provide a method for low-stress marking using the device of the first aspect, the method comprising: completing low-stress marking on the tube plate 5 by adjusting the position of the die station on the limiting plate 4 using the seal 1.

[0078] ​​According to the preferred embodiment, the method comprises: inserting 2-12 positioning pins 3 into the positioning pin holes 2-1 on the positioning plate 2, thereby fixing the tube holes on the tube plate 5 to be marked, inserting the limiting plate 4 into the limiting plate hole 2-2, adjusting the position of the die station on the limiting plate 4, and completing the low-stress marking on the tube plate 5 by using the steel stamp 1. Preferably, 3-9 positioning pins 3 are inserted into the positioning pin holes 2-1 on the positioning plate 2 to complete the above operation, and more preferably, 3 positioning pins 3 are inserted into the positioning pin holes 2-1 on the positioning plate 2 to complete the above operation.

[0079] During low-stress marking, the position of the die station on the limiting plate 4 is adjusted as needed. Specifically, the to-be-marked position 6 on the tube plate 5 is evenly divided into an even number of parts according to the size, and the structure of the limiting plate 4 is set according to the equal parts. For example, if the equal parts of the to-be-marked position 6 are 2, the limiting plate 4 can be a strip, and the limiting plate 4 is placed on the left side of the limiting hole plate 8, and then the die end of the steel stamp 1 is on the right side of the limiting hole plate 8 to complete the low-stress marking; conversely, the limiting plate 4 is placed on the right side of the limiting hole plate 8, and then the die end of the steel stamp 1 is on the left side of the limiting hole plate 8 to complete the low-stress marking. Alternatively, if the equal parts of the to-be-marked position 6 are 4, the limiting plate 4 is a four-corner limiting plate 4-2, that is, a die station is arranged at the upper right corner of the four-corner limiting plate 4-2, and the size of the die station occupies 1 / 4 of the total area of the limiting plate 4 (including the die station), the die end of the steel stamp 1 is clamped with the die station at the upper right corner of the four-corner limiting plate 4-2, and the low-stress marking at the upper right corner of the to-be-marked position 6 is completed; then, the four-corner limiting plate 4-2 is flipped, flipped up and down, and rotated by 180° to be placed, and the low-stress markings at the upper left corner, the lower right corner, and the lower left corner are completed, respectively.

[0080] In practice, there are dense tube holes on the tube plate 5, and when the low-stress marking is performed on the tube plate 5 of the heat exchanger in the field of pressure vessels and nuclear steam generators, it is required that the low-stress marking cannot be performed within a certain range around the tube holes, and therefore the to-be-marked position 6 is mostly rectangular, as shown in Figure 5

[0081] According to the preferred embodiment, the limiting plate 4 comprises a middle limiting plate 4-1 and a four-corner limiting plate 4-2, a die station is arranged at the upper right corner of the middle of the middle limiting plate 4-1, and the size of the die station occupies 1 / 8 of the total area of the limiting plate 4-1 (including the die station), a die station is arranged at the upper right corner of the four-corner limiting plate 4-2, and the size of the die station occupies 1 / 8 of the total area of the four-corner limiting plate 4-2 (including the die station), the four-corner limiting plate 4-2 completes the marking of the four-corner part of the to-be-marked position 6, and the middle limiting plate 4-1 completes the marking of the middle part of the to-be-marked position 6, and the low-stress marking is completed by adjusting the positions of the die stations on the middle limiting plate 4-1 and the four-corner limiting plate 4-2, as shown in Figures 3-4

[0082] ​​In use, the four corner limiting plate 4-2 is clamped on the positioning plate 2 at the limiting plate hole 2-2, and the steel stamp 1 character mold end is clamped on the right upper corner character mold station position of the four corner limiting plate 4-2, to complete the low stress marking at the right upper corner of the to-be-marked position 6; then, the four corner limiting plate 4-2 is respectively mirror image flipped, flipped up and down, and placed at 180°, to complete the low stress marking at the left upper corner, the right lower corner and the left lower corner of the to-be-marked position 6; similarly, the middle limiting plate 4-1 is clamped on the positioning plate 2 at the limiting plate hole 2-2, and the steel stamp 1 character mold end is clamped on the character mold station position thereof, to complete the low stress marking at the middle right upper corner of the to-be-marked position 6; then, the middle limiting plate 4-1 is respectively mirror image flipped, flipped up and down, and placed at 180°, to complete the low stress marking at the middle left upper corner, the right lower corner and the left lower corner of the to-be-marked position 6.

[0083] In the present application, the hammering steel stamp 1 handle end is used to stamp the character mold on the tube plate 5.

[0084] In the present application, the hammering steel stamp 1 handle end is used to stamp the character mold on the tube plate 5.

[0085] According to the present application, the tube hole 7 itself is used for positioning, the to-be-marked position 6 is calculated, the position of the character mold station on the limiting block 4 is adjusted, and the low stress marking is completed on the very narrow to-be-marked position 6 on the tube plate 5, without exceeding the boundary of the to-be-marked position 6 or the boundary limited by the tube hole group of the tube hole 5, so that the product quality qualification rate reaches 100%.

[0086] Embodiment

[0087] The present application is further described below by specific examples, but these examples are merely exemplary and do not constitute any limitation on the protection scope of the present application.

[0088] Example 1

[0089] Operation requirement: 8 characters (character height 4mm, character width 3mm) are marked in the regular hexagonal positioning area 2-4 on the nuclear power steam generator heat exchanger tube plate 5, the tube hole diameter on the tube plate 5 is 22mm, which is the limiting area 2-3, and the low stress marking cannot be performed in this area. Among them, the tube hole diameter on the tube plate 5 is 12.25mm, and the center distance between the tube holes is 17.8mm, as shown in Figure 6 and 9 .

[0090] After calculation, the size of the to-be-marked position 6 on the tube plate 5 is 12.2mm×8.4mm, as shown in Figure 6 .

[0091] The device shown in Figure 1 is used to perform low stress marking according to the following steps:

[0092] Three positioning pins 3 are inserted into the positioning pin holes 2-1 on the positioning plate 2 at intervals, and then into the pipe holes in the regular hexagonal positioning area 2-4 on the tube plate 5, and the four-corner limiting plate 4-2 is clamped on the limiting plate hole 2-2 on the positioning plate 2 as shown in the figure, and the character mold end of the steel seal 1 is clamped at the character mold work position, and the low stress mark at the upper right corner of the to-be-marked position 6 is completed by hammering the handle end of the steel seal 1. Figure 7 The four-corner limiting plate 4-2 is flipped, turned upside down, and rotated 180°, respectively, and placed, and the low stress marks at the upper left corner, the lower right corner, and the lower left corner of the to-be-marked position 6 are completed.

[0093] Then, the middle limiting plate 4-1 is clamped on the limiting plate hole 2-2 on the positioning plate 2 as shown in the figure, and the character mold end of the steel seal 1 is clamped at the character mold work position, and the low stress mark at the upper right corner of the to-be-marked position 6 is completed by hammering the handle end of the steel seal 1. Figure 8 The middle limiting plate 4-1 is flipped, turned upside down, and rotated 180°, respectively, and placed, and the low stress marks at the upper left corner, the lower right corner, and the lower left corner of the to-be-marked position 6 are completed.

[0094] In the description of the present application, it should be pointed out that the terms "upper", "lower", "inner", "outer", "front", "back" and the like indicate the orientation or positional relationship in the working state of the present application, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", "fourth" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0095] In the description of the present application, it should be pointed out that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0096] The application has been described in detail with reference to preferred embodiments and exemplary examples. However, it should be understood that these detailed description and examples are merely illustrative of the application and are not intended to limit the scope of the application. Various modifications, equivalent substitutions or modifications can be made to the technical content and embodiments of the application without departing from the spirit and protection scope of the application, and these all fall within the protection scope of the application. The protection scope of the application is subject to the appended claims.

Claims

1. A method of low stress marking using a device for making low stress marks in a group of holes, characterized in that, The device comprises a seal (1) and a limiting plate (4), the seal (1) has a character matrix end at one end and a handle end at the other end, the limiting plate (4) is provided with a character matrix station which can be clamped with the character matrix end of the seal (1); The device further comprises a positioning plate (2) and a positioning pin (3) for fixing the limiting plate (4), the positioning plate (2) is provided with a positioning pin hole (2-1) and a limiting plate hole (2-2), the positioning pin (3) is inserted into the positioning pin hole (2-1) on the positioning plate (2) to be fixed with the pipe hole (7) on the pipe plate (5) to be marked, the limiting plate (4) is placed at the limiting plate hole (2-2), and the seal (1) is used to complete low-stress marking on the pipe plate (5), wherein the pipe plate (5) is distributed with dense pipe holes; The materials of the positioning plate (2) and the limiting plate (4) are nickel-based alloys; The limiting plate (4) is selected from a middle limiting plate (4-1) or a four-corner limiting plate (4-2), wherein the middle limiting plate (4-1) is provided with a character matrix station at the upper right corner of the middle part, and the four-corner limiting plate (4-2) is provided with a character matrix station at the upper right corner; The method comprises the following steps: adjusting the embedding mode of the middle limiting plate (4-1) or the four-corner limiting plate (4-2) to adjust the position of the character matrix station on the position to be marked (6), inserting the character matrix end of the seal (1) into the character matrix station, and hammering the handle end of the seal (1) to complete low-stress marking, wherein the four-corner limiting plate (4-2) is used for low-stress marking of the four-corner part of the position to be marked (6), and the middle limiting plate (4-1) is used for low-stress marking of the middle part of the position to be marked (6); The four-corner limiting plate (4-2) or the middle limiting plate (4-1) adjusts the embedding angle by flipping or rotating, and then is embedded in the positioning plate (2) for low-stress marking of the required part of the position to be marked (6).

2. The method of low stress marking according to claim 1, wherein, The shape and size of the limiting plate (4) cannot exceed the range of the position to be marked (6), and the shape is any one of a square, a circle, a trapezoid and a rhombus.

3. The method of low stress marking according to claim 1, wherein, The shape of the character matrix station provided on the limiting plate (4) and the character matrix end of the seal (1) is a square.

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