CN113059063A

CN113059063A - Mold design method and processing method of grid straps

Info

Publication number: CN113059063A
Application number: CN202110437556.7A
Authority: CN
Inventors: 段华平; 钱飞; 曹光伟; 郑波; 周勇; 仇勇; 冯健
Original assignee: Ningbo Kdpr Tool Technology Co ltd
Current assignee: Ningbo Kdpr Tool Technology Co ltd
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2021-07-02
Anticipated expiration: 2041-04-22
Also published as: CN113059063B

Abstract

The invention provides a mold design method of a grid strip, belonging to the technical field of molds and comprising the following steps: a main frame; a lower die holder; an upper die holder; and a controller. Also provides a method for processing the grid straps, which belongs to the technical field of moulds and comprises the following steps: the side guide plate material guiding, the punching of the positive nail hole, the punching of the rigid convex groove, the slitting of the muddy wing, the front forming spring, the back forming rigid convex, the punching of the muddy wing edge, the punching of the muddy wing, the cutting of the muddy wing, the trimming, the front forming muddy wing, the back forming muddy wing, the adjustment of the transverse bending and the cutting. The invention has the beneficial effects that: the accurate location of the stamping process is guaranteed, the problems that the whole deformation shrinkage of the grid frame strips is large and the strips can be transversely bent finally in the rolling and stamping process are well solved, and the high precision of the grid frame strips is guaranteed.

Description

Mold design method and processing method of grid straps

Technical Field

The invention belongs to the technical field of molds, and relates to a mold design method and a processing method of grid straps.

Background

A certain number of fuel rods are arranged at certain intervals (e.g., 5 x 5 or 17 x 17, etc.) and fixed as a bundle, and various structural components, called a reactor fuel assembly, are added, the reactor fuel assembly is mainly composed of a combustion assembly grid and fuel rods, the combustion assembly grid is composed of inner and outer straps, the outer strap refers to the strap constituting the outer frame of the grid, and the inner strap refers to the strap separating each fuel rod.

According to the safety requirements, the reactor core is required to be capable of withstanding the specified limit accident conditions, namely, assuming that a coolant loss of coolant accident (LOCA) and a Safety Shutdown Earthquake (SSE) occur simultaneously, under the two loads of LOCA and SSE, the movement of the reactor internals can cause the core to generate lateral displacement, and the lateral displacement of the core can cause the nuclear fuel assemblies to generate lateral displacement. Under four types of operating conditions, the main criteria are to ensure that the reactor can be shut down urgently, such as ensuring that a safe injection system operates normally and a sufficient number of control rods are inserted into the reactor core, and the common design criteria are that permanent deformation of the lattice frame does not occur.

The existing grid straps do not have a unified and general mold design method and a processing method, so the grid straps developed every time are also eight-door, but the grid straps are often flawed frequently due to unreasonable mold design methods and processing methods, so that problems such as large deformation and shrinkage of the whole grid straps and the like easily occur, and the manufactured grid straps are difficult to meet higher use requirements, so that the grid straps have larger improvement space.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a method for designing a mold of a grid strap and a processing method thereof.

The purpose of the invention can be realized by the following technical scheme:

a method of mold design for grid straps, comprising:

the main frame is provided with a die holder installation cavity;

the lower die holder is arranged in the die holder mounting cavity and connected with the main rack, a material guide device is detachably arranged on the lower die holder, and the material guide device is provided with a side guide plate for a positioning grid frame strip;

the upper die holder is arranged in the die holder installation cavity, the upper die holder can move towards the lower die holder, and the upper die holder and the lower die holder are provided with a driving cylinder and a machining head;

and the controller is arranged on the main frame, the driving air cylinder is connected with the controller, and the controller can drive the processing head to process the lattice frame strip through the driving air cylinder according to the execution program.

Preferably, the processing head is a punch or a drill or a cutting head.

The method for processing the grid straps comprises a method for designing a mold of the grid straps, and further comprises the following steps of:

s1: guiding materials by a side guide plate: the material is accurately guided by the side guide plate, so that the material belt is prevented from shifting left and right;

s2: punching a guide nail hole: fine punching of the guide nail holes on the material belt is carried out, and accurate positioning of a subsequent punching process is guaranteed;

s3: punching a steel convex groove: the rigid convex groove needs to be punched before rigid convex forming;

s4: punching a spring slot: the spring slot needs to be punched before the spring is formed;

s5: cutting the muddy wings: the stirring wing is cut before the stirring wing is formed, so that the subsequent bending of the stirring wing is facilitated;

s6: forming a spring on the front surface: the spring punching process is carried out at the front end of the die, so that the overall deformation and shrinkage of the strip can be effectively reduced;

s7: forming a rigid convex on the back side: the process of punching the rigid convex strip is placed at the front end of the die to punch the rigid convex strip, so that the overall deformation and shrinkage of the strip can be effectively reduced;

s8: punching and stirring the muddy wing edge: the shape of the stirring wing is a bending piece, and the periphery needs to be cut in advance;

s9: flushing and stirring the muddy wings: the periphery of the muddy wing is cut so as to be convenient for bending the muddy wing later;

s10: cutting and stirring the muddy wings: the guide pipe is not provided with the muddy wing, and the redundant muddy wing needs to be cut off before the guide pipe is formed;

s11: trimming: the lower edge of the strip needs to be trimmed;

s12: front molding of the stirring wing: the front molding of the multiple groups of stirring wings is completed by punching of a group of convex-concave dies;

s13: back-side forming of the muddy wing: the reverse side forming of the multiple groups of stirring wings is finished by punching of the other group of convex-concave dies;

s14: adjusting transverse bending: the strip is rolled and punched to cause the finally punched strip to be transversely bent, and the strip is corrected by adjusting a transverse bending device;

s15: cutting: all the punching processes are completed and the strip is separated from the strip.

Preferably, in S10, the tenon punching is performed after the completion of the cutting and stirring wing: the strip tenons and the outer strip slots are mutually spliced, each strip tenon is punched out by the same group of convex-concave dies at one time, the assembly gap between the strip and the outer strip is ensured to be consistent, and the unit size of each strip is effectively ensured.

Preferably, in S13, the front-side forming sleeve is performed after the front and back sides of the mixing wing are formed: the sleeve penetrates through the whole strip, and the station is required to be placed at the rear section of the die for punching and forming so as to ensure that the convex-concave die at the front end of the die is avoided;

in S13, the back-side forming sleeve is performed after the front-side forming sleeve is completed: the sleeve penetrates through the whole strip, and the working position is required to be placed at the rear section of the die for punching and forming so as to ensure that the convex-concave die at the front end of the die is kept away.

Preferably, in S13, the reverse forming sleeve is post-punched with the slot: the multi-forming process of the strip can reduce the deformation of the strip in the step pitch direction after the strip is punched and punched in front and then the slot is punched.

Preferably, in S14, trimming is performed after the adjustment of the lateral bending: after the strip is punched, the redundant lap edges of the material strip need to be punched;

preferably, in S14, the piercing is performed after the trimming is completed: the structure of the muddy wing edge is complex, the side materials cannot be directly cut off by the punch, and the strip is firstly punctured and then is broken;

in S14, trimming after the piercing is completed: after the strip is punched, the redundant overlap of the strip needs to be punched and cut.

Preferably, in S14, the trimming is performed by: in the punching process, the strip is in a fan-shaped state, and the strip is corrected by a fan-shaped adjusting device;

in S14, the warpage is adjusted after the completion of the fan adjustment: the strip is warped locally in the punching process, and the strip is corrected by adjusting the warping device.

Preferably, in S3, the just-convex chamfering is performed just after the convex groove punching is completed: chamfering the two sides of the rigid projection is needed to be finished before the rigid projection is formed, and chamfering is simultaneously carried out on the front surface and the back surface of the rigid projection groove, so that the chamfering consistency of the front surface and the back surface of the strip is ensured;

in S4, the spring chamfer is performed after the spring slot hole is punched: before the spring is formed, chamfering of the spring groove is needed to be finished, and chamfering is simultaneously carried out on the front side and the back side of the spring groove hole, so that the consistency of chamfering on the front side and the back side of the strip is ensured;

in S8, chamfering the edges of the muddy wing after the punching is completed: chamfering the front and back surfaces of the edge at the same time on the die, so as to ensure the consistency of chamfering the front and back surfaces of the strip;

in S8, punching the guide tube notch after the edge chamfering is completed: the structure of the guide pipe is formed by front and back surfaces, and a lower end notch needs to be punched before forming;

in S11, edge chamfering is performed after the lower edge trim of the strip is completed: chamfering is simultaneously carried out on the front surface and the back surface of the edge cutting at one time on the die, so that the chamfering consistency of the front surface and the back surface of the strip is ensured.

Compared with the prior art, the invention has the beneficial effects that:

1. the accurate location of the stamping process is guaranteed, the problems that the whole deformation shrinkage of the grid frame strips is large and the strips can be transversely bent finally in the rolling and stamping process are well solved, and the high precision of the grid frame strips is guaranteed.

2. The multi-forming process of the strip can reduce the deformation of the strip in the step pitch direction after the slot is punched in front, and in the actual manufacturing process, the width of the slot from outside to inside is increased from small to large in order to facilitate splicing.

3. The strip is punctured earlier and is cut edge again, can be better with the strip separate, prevent to produce unnecessary deformation when leading to separating the framework strip from the material area because the structure on stirring wing limit is complicated.

4. Bending and warping in the punching process can be corrected by adjusting the fan shape and the warping, the manufacturing precision of the grid strips is guaranteed, and transverse bending generated in the rolling and punching processes is corrected.

5. The chamfering of the rigid convex and the spring slot hole is carried out for enhancing the working strength of the band sheet unit, the chamfering of the lower edges of the muddy wing edge and the band is carried out for smoothing the band sheet unit, the unnecessary influence of burrs on the muddy wing is prevented, and meanwhile, the scratch of workers during discharging is prevented.

Drawings

Fig. 1 is a schematic structural diagram of an upper die holder according to a preferred embodiment of the invention.

Fig. 2 is a schematic processing diagram of a material guiding device according to a preferred embodiment of the invention.

Fig. 3 is a schematic view illustrating the processing of the lower die base according to a preferred embodiment of the invention.

In the figure, 100, a lower die holder; 200. a material guiding device; 300. a side guide plate; 400. an upper die holder; 410. a driving cylinder; 420. a machining head.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

Moreover, descriptions of the present invention as relating to "first," "second," "a," etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating a number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

As shown in fig. 1, 2 and 3, a method for designing a mold for grid straps includes:

and the main frame (not shown) is provided with a die holder installation cavity (not shown).

The lower die holder 100 is arranged in the die holder mounting cavity and connected with the main frame, the lower die holder 100 is detachably provided with a material guiding device 200, and the material guiding device 200 is provided with a side guide plate 300 for a positioning grid strip.

An upper die holder 400 disposed in the die holder installation cavity, the upper die holder 400 being movable toward the lower die holder 100, the upper die holder 400 and the lower die holder 100 each being provided with a driving cylinder 410 and a machining head 420,

and a controller (not shown) disposed on the main frame, wherein the driving cylinder 410 is connected to the controller, and the controller can drive the processing head 420 to process the grid strips through the driving cylinder 410 according to the execution program.

It should be noted here that the processing mold for the grid straps is specially designed for the grid straps, and in the actual use process, the material guiding device 200 is installed on the lower die base 100 to ensure that the lower die base 100 is fixed, and then the material strap is placed on the material guiding device 200, and the processing head 420 on the lower die base 100 and the upper die base 400 is controlled by a program preset by the controller to perform the manufacturing process on the material strap. In the actual use process, the controller can often input a multi-section program, so that one die can process a plurality of grid strips with different specifications or shapes.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, the processing head 420 may be a punch, a drill, or a cutting head, and in the actual manufacturing process, the processing head 420 may be any member related to the manufacturing process of the lattice strips.

As shown in fig. 1, 2 and 3, a method for processing a grid strap (it should be specifically noted that the grid strap mainly comprises a strap unit, a rigid convex groove, a spring slot hole, a mixing wing, a guide pipe, a sleeve pipe and the like), comprises a method for designing a mold of the grid strap, and further comprises the following steps:

s1: guiding materials by a side guide plate: the material strips are prevented from shifting left and right through the accurate material guiding of the side guide plates, the side guide plates are of plate-shaped structures used for positioning the grid frame strips on the material guiding device, and the side guide plates need high manufacturing accuracy to ensure accurate material guiding;

s2: punching a guide nail hole: fine punching of the guide nail holes on the material belt is mainly used for improving the processing precision of the grid straps and preventing the grid straps from deviating;

s3: punching a steel convex groove: the rigid convex groove needs to be punched before the rigid convex forming, if the rigid convex groove is punched after the rigid convex is punched, the rigid convex is easy to deform when the rigid convex groove is punched because the rigid convex is closer to the rigid convex groove;

s4: punching a spring slot: the spring slot needs to be punched before the spring is formed, and if the spring slot is punched after the spring is formed, the formed spring is easy to deform when the spring slot is punched;

s5: cutting the muddy wings: the muddy wing is cut before the muddy wing is formed, so that the muddy wing is convenient to bend subsequently, the muddy wing needs to bend inwards or outwards relative to the plane where the band-piece units are located, the bending directions of the muddy wings of two adjacent band-piece units are possibly inconsistent, the muddy wing needs to be cut before the muddy wing is formed, and the muddy wing is used for causing additional flow mixing between each flow passage in the fuel assembly and between adjacent assemblies;

s6: forming a spring on the front surface: the process of punching the spring is placed at the front end of a die to effectively reduce the overall deformation and shrinkage of the strap, and it needs to be noted that the spring is not a spiral elastic connecting piece commonly seen in industrial machinery, but is a proper term well known to those skilled in the art, and the spring refers to an elastic area arranged in the middle of a strap unit, mainly plays a role in fixing a fuel rod and provides proper clamping force;

s8: punching and stirring the muddy wing edge: the shape of the muddy wing is a bending piece, the periphery of the muddy wing needs to be cut in advance, and if the muddy wing is bent first and then the edge of the muddy wing is cut, the bending angle of the muddy wing is easy to deform;

s9: flushing and stirring the muddy wings: the periphery of the muddy wing is cut so as to be convenient for bending the muddy wing later, and if the muddy wing is bent first and then the edge of the muddy wing is cut, the bending angle of the muddy wing is easy to deform;

s10: cutting and stirring the muddy wings: the guide pipe is characterized by providing guidance for the movement of the control rod and providing a buffer effect for the falling of the control rod;

s11: trimming: the lower edge of the strip needs to be trimmed;

s14: adjusting transverse bending: the strip is subjected to transverse bending in the rolling and punching processes, and is corrected by adjusting a transverse bending device which is one of processing heads;

In the above embodiment, the number of the strap elements is at least two, the rigid convex groove, the spring slot hole, the mixing wing, the guide tube, the sleeve and other features are all located in the strap elements, the strap elements are connected in sequence, a plurality of strap elements with different shapes are connected in sequence to form the grid strap, the specification of the grid strap is not specifically specified, and the grid strap may be composed of seven strap elements or seventeen strap elements.

Preferably, in the above embodiment, the precise positioning of the stamping process is ensured, the problems that the overall deformation shrinkage of the grid straps is large and the finally stamped straps are bent in the rolling and stamping process of the material strap are solved well, and the high precision of the grid straps is ensured.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, in S10, the tenon punching is performed after the completion of the cutting and stirring wing: the strip tenon and the outer strip slot splice mutually, and every strip tenon is once washed out with the punch-die of the same group, guarantee that strip and outer strip assembly gap are unanimous, effectively guarantee each tape unit size, and is preferred, and the tenon is used for splicing mutually with outer strip slot, and strip and outer strip assembly gap are unanimous in consequently needing to guarantee, and the size that the tenon needs each tape unit is the same simultaneously.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, in S13, the front surface molding sleeve is performed after the front and back surfaces of the paddle are molded: the sleeve penetrates through the whole strip, and the station is required to be placed at the rear section of the die for punching and forming so as to ensure that the convex-concave die at the front end of the die is avoided;

As shown in fig. 1, 2, and 3, in the above embodiment, in S13, the reverse-molding sleeve is inserted into the slot after completion of the back-punching: the multi-forming process of the strip can reduce the deformation of the strip in the step pitch direction after the slot is punched in front, and in the actual manufacturing process, the width of the slot from outside to inside is increased from small to large in order to facilitate splicing.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, trimming is performed after the adjustment of lateral bending is completed in S14: after the strip is punched, the redundant lapping edges of the strip need to be punched, and preferably, the trimming edges are used for punching the redundant parts of the strip, so that the strips of the whole grid frame are simpler and smoother.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, in S14, after the trimming is completed, piercing is performed: the structure of the muddy wing edge is complex, the side materials cannot be directly cut off by the punch, and the strip is firstly punctured and then is broken;

in S14, trimming after the piercing is completed: the strip punching is accomplished and is needed to cut off the unnecessary scrap (bridge) of material area, and is preferred, punctures the material area earlier and cuts edge again, can be better with the strip with the material area separate, prevent to produce unnecessary deformation when leading to separating the framework strip from the material area because the structure on stirring wing limit is complicated.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, in S14, after the trimming is completed, the fan-shaping is performed: in the punching process, the strip is in a fan-shaped state, and the strip is corrected by a fan-shaped adjusting device;

in S14, the warpage is adjusted after the completion of the fan adjustment: the strip is partially warped in the punching process, the strip is corrected by adjusting the warping device, and preferably, the bending warping in the punching process can be corrected by adjusting the fan shape and the warping, so that the manufacturing precision of the grid strip is ensured, and the transverse warping generated in the rolling and punching processes is corrected.

As shown in fig. 1, 2, and 3, in addition to the above embodiment, in S3, immediately after the completion of the convex groove punching, the convex chamfering is performed: before the rigid convex forming, chamfering of the rigid convex groove is needed to be finished, chamfering is simultaneously carried out on the front surface and the back surface of the rigid convex groove, the consistency of chamfering on the front surface and the back surface of the strip is ensured, and the manufacturing precision is ensured;

in S4, the spring chamfer is performed after the spring slot hole is punched: before the spring is formed, chamfering is needed to be finished on two sides of the spring, and the front and back sides of the spring slot are chamfered simultaneously, so that the consistency of chamfering on the front and back sides of the strip is ensured, and the manufacturing precision is ensured;

in S8, chamfering the edges of the muddy wing after the punching is completed: chamfering the front and back surfaces of the edge at the same time on the die, so that the chamfering consistency of the front and back surfaces of the strip is ensured, and the manufacturing precision is ensured;

in S8, punching the guide tube notch after the edge chamfering is completed: the guide tube structure is formed on the front side and the back side, a lower end notch needs to be punched before forming, and the guide tube provides guide for the movement of a control rod and provides a buffer effect for the falling of the control rod;

in S11, edge chamfering is performed after the lower edge trim of the strip is completed: chamfering is simultaneously carried out on the front surface and the back surface of the edge cutting at one time on the die, so that the chamfering consistency of the front surface and the back surface of the strip is ensured, and the manufacturing precision is ensured.

Preferably, the chamfering of the rigid convex and the spring slot hole is performed respectively to strengthen the working strength of the belt sheet unit, and the chamfering of the muddy wing edge and the lower edge of the belt is performed to smooth the belt sheet unit, so that the muddy wing is prevented from being unnecessarily affected by burrs, and meanwhile, workers are prevented from being scratched when unloading.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A method of mold design for grid straps, comprising:

the main frame is provided with a die holder installation cavity;

2. The method of claim 1, wherein the step of designing the mold comprises: the processing head is a punch or a drill or a cutting head.

3. A method of manufacturing a grid strap, comprising a method of designing a mould for a grid strap according to any of claims 1 to 2, further comprising the steps of:

s11: trimming: the lower edge of the strip needs to be trimmed;

4. A method of manufacturing a grid strap as claimed in claim 3, wherein: in S10, the tenon punching is carried out after the completion of the cutting and stirring wing: the strip tenons and the outer strip slots are mutually spliced, each strip tenon is punched out by the same group of convex-concave dies at one time, the assembly gap between the strip and the outer strip is ensured to be consistent, and the unit size of each strip is effectively ensured.

5. The method of manufacturing a grid strap of claim 4, wherein: in S13, the front surface forming sleeve is carried out after the front surface and the back surface of the stirring wing are formed: the sleeve penetrates through the whole strip, and the station is required to be placed at the rear section of the die for punching and forming so as to ensure that the convex-concave die at the front end of the die is avoided;

6. The method of manufacturing a grid strap of claim 5, wherein: in S13, the reverse side forming sleeve is finished with the insert groove: the multi-forming process of the strip can reduce the deformation of the strip in the step pitch direction after the strip is punched and punched in front and then the slot is punched.

7. A method of manufacturing a grid strap as claimed in claim 3, wherein: in S14, trimming after the adjustment of the lateral bending is completed: after the strip is punched, the redundant overlap of the strip needs to be punched and cut.

8. The method of manufacturing a grid strap of claim 7, wherein: in S14, piercing is performed after the trimming is completed: the structure of the muddy wing edge is complex, the side materials cannot be directly cut off by the punch, and the strip is firstly punctured and then is broken;

9. The method of manufacturing a grid strap of claim 8, wherein: in S14, performing fanning after the trimming is completed: in the punching process, the strip is in a fan-shaped state, and the strip is corrected by a fan-shaped adjusting device;

10. A method of manufacturing a grid strap as claimed in claim 3, wherein: in S3, the just-convex chamfer is performed after the just-convex groove punching is completed: before the rigid convex forming, chamfering of the rigid convex groove is needed to be finished, chamfering is simultaneously carried out on the front surface and the back surface of the rigid convex groove, and the consistency of chamfering on the front surface and the back surface of the strip is ensured;

in S4, the spring chamfer is performed after the spring slot hole is punched: before the spring is formed, chamfering is needed to be finished on two sides of the spring, and the front side and the back side of a spring slot hole are chamfered simultaneously, so that the consistency of chamfering on the front side and the back side of the strip is ensured;