阅读说明：本技术 一种大尺寸薄壁管件成形模具的加热装置及分区控温方法 (heating device and partitioned temperature control method for large-size thin-wall pipe fitting forming die ) 是由 何祝斌 苑世剑 杨松 郑凯伦 阮祥钢 刘任忠 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种大尺寸薄壁管件成形模具的加热装置及分区控温方法,包括导热板、加热块、感应线圈和温控器,导热板上设置有若干个加热块,加热块设置有不同的长度和形状,加热块能够组合出不同的加热区域,每个加热块上绕设有感应线圈,感应线圈与温控器电连接。根据导热板上各分区域的热输入量,设计并加工出各分区域上需设置的加热块、感应线圈的形状和尺寸,并将加热块按照设定组合安装在导热板上相应的位置。本发明通过使用分体式的加热块在导热板上进行组合,使加热装置的加工简单、成本低,加热块可根据管坯的形状灵活改变模具上不同分区域的输入热量值,从而能对各分区域的温度进行快速、不同梯度、分区域的调控。(the invention discloses a heating device and a partitioned temperature control method for a large-size thin-wall pipe fitting forming die. According to the heat input quantity of each subarea on the heat conducting plate, the shapes and the sizes of the heating blocks and the induction coils which need to be arranged on each subarea are designed and processed, and the heating blocks are arranged at corresponding positions on the heat conducting plate according to set combination. The split heating blocks are combined on the heat conducting plate, so that the heating device is simple to process and low in cost, and the heating blocks can flexibly change the input heat values of different subareas on the die according to the shape of a tube blank, so that the temperature of each subarea can be quickly regulated and controlled in different gradients and subareas.)

1. A heating device of a large-size thin-wall pipe fitting forming die is characterized in that: including heat-conducting plate, heating piece, induction coil and temperature controller, be provided with a plurality of heating piece on the heat-conducting plate, the heating piece is provided with different length and shape, the heating piece can make up out different heating regions, every around being equipped with induction coil on the heating piece, induction coil with the temperature controller electricity is connected, the heat-conducting plate is used for being connected with forming die.

2. The heating device for the forming die of the large-size thin-walled tube according to claim 1, wherein: the heating block is internally provided with cooling channels with different lengths, and the cooling channels are connected with refrigeration equipment through pipelines.

3. The heating device for the forming die of the large-size thin-walled tube according to claim 1, wherein: the heating block is fixed on the heat-conducting plate through a bolt, and the induction coil is a copper pipe coil.

4. The heating device for the forming die of the large-size thin-walled tube according to claim 1, wherein: the heating block is a rectangular block, an arc block or an irregular block.

5. The heating device for the forming die of the large-size thin-walled tube according to claim 1, wherein: the heating blocks are arranged on the heat conducting plate at intervals which are changed or not changed according to the heating areas of different tube blanks in a combined mode of length and/or shape.

6. A zoning temperature control method for a heating device of a large-size thin-wall pipe fitting forming die is characterized by comprising the following steps: the heating device for the forming die of the large-size thin-wall pipe fitting based on any one of claims 1 to 5 comprises the following steps:

Determining a set temperature field of an integral area of a heat conduction plate on a tube blank forming die by a theoretical calculation method of thermodynamic simulation, obtaining the set temperature fields of subareas at different positions of the heat conduction plate, and further determining the input heat value and current value of each subarea on the heat conduction plate;

Designing and processing shapes and sizes of heating blocks and induction coils to be arranged on the sub-areas according to the heat input quantity of the sub-areas on the heat conduction plate, installing the induction coils on the heating blocks, and installing the heating blocks at corresponding positions on the sub-areas of the heat conduction plate by bolts according to a set combination mode;

And step three, introducing corresponding current values into the induction coils in each sub-area through a temperature controller, heating the heating block, heating the heat conduction plate in the sub-areas until the set time, and then cooling the forming die.

7. The method for controlling the temperature of the heating device of the forming die of the large-size thin-wall pipe fitting according to claim 6, wherein the method comprises the following steps: and step four, when the pipe blank is formed or the temperature controller reaches the set time, the temperature controller cuts off the current introduced into the induction coil, the refrigeration equipment is started and communicated with the cooling channel in the heating block, so that the temperature of the heating block is rapidly reduced, and the rapid cooling of the hot forming die is realized.

8. the method for controlling the temperature of the heating device of the forming die of the large-size thin-wall pipe fitting according to claim 6, wherein the method comprises the following steps: the setting combination mode of the heating blocks in the second step comprises any one combination mode or a plurality of coexistence combination modes in the equal spacing and/or unequal spacing, the equal length and/or unequal length, the same shape and/or different shape, the same direction and/or different direction, the same material and/or different material, the same temperature and/or different temperature, grouping and/or non-grouping.

Technical Field

The invention relates to the technical field of hot air pressure forming dies, in particular to a heating device and a partition temperature control method for a large-size thin-wall pipe fitting forming die.

Background

When the thin-wall pipe fitting is formed by hot air pressure, the die needs to be heated to a set temperature before the pipe fitting is formed, and the die is cooled gradually after the pipe fitting is formed. When the temperature is raised by heating and cooled, the die is obviously expanded with heat and contracted with cold, and the change of the shape and the size of the die caused by the expansion with heat and the contraction with cold and the influence on the size precision of the final part must be considered.

For a hot air pressure forming die for large-size thin-wall pipe fittings, the following problems can occur: (1) because the sizes of the die in three directions are large, uncoordinated thermal expansion is easy to occur due to unreasonable temperature distribution in the heating process, so that unreasonable thermal stress is generated in the die, and the die can be deformed or even damaged when the thermal stress is large; (2) when the mold cavity is complex, the size of the mold cavity is not coordinated or uncontrollable changed due to unreasonable temperature distribution at each part of the heated mold, so that the precision of the finally formed part is not enough; (3) the guide posts and the guide sleeves of the upper die and the lower die cannot be matched due to possible deformation and dislocation of the die cavity, the die parting surface and the like during heating, and the guide precision of the dies is poor or even the dies cannot be opened and closed smoothly; (4) after a press machine applies a mold closing force to a mold and applies high-pressure gas to the interior of a pipe blank, the mold cavity is under the action of complex load, and the mold cavity and the whole mold are likely to generate more complex deformation; (5) when the temperature distribution in the die cavity is unreasonable, the contact sequence, the contact time, the contact area and the like of the large-size tube blank and the die are unreasonable, so that qualified parts cannot be smoothly formed finally. In the process of cooling the die after the pipe fitting is formed, the problem similar to the heating process is also generated.

Therefore, when the tube blank of the large-size thin-wall tube fitting is formed by hot air pressure, the heating process, the using process and the cooling process of the die need to be accurately controlled. The mold damage caused by unreasonable temperature rise in the heating and temperature rise process is avoided, reasonable temperature distribution (sometimes uniform temperature distribution and non-uniform temperature field under more conditions) on a mold cavity and a mold body in the use process is guaranteed, and the problem similar to the heating process caused by unreasonable temperature drop in the cooling and temperature drop process is also guaranteed.

At present, the heating of a hot air pressure forming die for large-size thin-wall pipe fittings mainly adopts an induction heating mode, one mode is to directly heat a die body, and the other mode is to heat an independent heating plate firstly and then transfer the heated plate to the die body.

no matter the heating is carried out on the die body or the heating plate, grooves with certain depth and regular distribution are formed in the die body or the heating plate in advance, copper pipe coils with specific size specifications are placed in the grooves, and a magnetic field generated after the copper pipe coils are electrified is utilized to heat heating blocks between the adjacent copper pipe coils. Since the grooves have the same dimension and are uniformly distributed, the copper tube coils arranged in the grooves also have the same dimension and spacing.

by adopting the design mode, although the processing cost of the groove and the manufacturing difficulty of the copper pipe coil can be reduced, the temperature distribution on the die cannot be effectively controlled in the heating, using and cooling processes, so that the possible problems of the tube blank hot air pressure forming die in the heating, using and cooling processes cannot be avoided.

In order to solve the problems that the large-size (length direction and diameter direction) thin-wall pipe fitting hot air pressure forming die is difficult to realize quick and effective temperature regulation during heating temperature rise, part forming and cooling temperature drop, the die is easy to deform and even crack after heating temperature rise and cooling temperature drop, the die is difficult to guide and open and close, the die cavity has poor size precision, the temperature distribution on a pipe blank to be formed is unreasonable during part forming, and the like, a method capable of realizing the zone heating and cooling of the large-size thin-wall pipe fitting hot air pressure forming die is needed.

disclosure of Invention

The invention aims to provide a heating device and a partitioned temperature control method for a large-size thin-wall pipe fitting forming die, which are used for solving the problems in the prior art, rationalizing the heating temperature distribution in the pipe fitting forming process and realizing the quick and effective adjustment of the temperature of the forming die in the using process.

in order to achieve the purpose, the invention provides the following scheme:

The invention provides a heating device of a large-size thin-wall pipe fitting forming die, which comprises a heat conducting plate, heating blocks, induction coils and a temperature controller, wherein the heat conducting plate is provided with a plurality of heating blocks, the heating blocks are provided with different lengths and shapes, the heating blocks can be combined into different heating areas, each heating block is wound with an induction coil, the induction coils are electrically connected with the temperature controller, and the heat conducting plate is used for being connected with the forming die.

preferably, cooling channels with different lengths are arranged in the heating block, and the cooling channels are connected with the refrigeration equipment through pipelines.

preferably, the heating block is fixed on the heat conducting plate through a bolt, and the induction coil is a copper pipe coil.

Preferably, the heating block is a rectangular block, an arc block or an irregular block.

Preferably, the heating blocks are arranged on the heat conduction plate at intervals which are changed or not changed according to the heating areas of different tube blanks in a combined mode of length and/or shape.

The invention also relates to a partitioned temperature control method of the heating device of the large-size thin-wall pipe fitting forming die, which is based on the heating device of the large-size thin-wall pipe fitting forming die and specifically comprises the following steps:

Determining a set temperature field of an integral area of a heat conduction plate on a tube blank forming die by a theoretical calculation method of thermodynamic simulation, obtaining the set temperature fields of subareas at different positions of the heat conduction plate, and further determining the input heat value and current value of each subarea on the heat conduction plate;

designing and processing shapes and sizes of heating blocks and induction coils to be arranged on the sub-areas according to the heat input quantity of the sub-areas on the heat conduction plate, installing the induction coils on the heating blocks, and installing the heating blocks at corresponding positions on the sub-areas of the heat conduction plate by bolts according to a set combination mode;

And step three, introducing corresponding current values into the induction coils in each sub-area through a temperature controller, heating the heating block, heating the heat conduction plate in the sub-areas until the set time, and then cooling the forming die.

Preferably, the method also comprises a fourth step, when the pipe blank is formed or the temperature controller reaches the set time, the temperature controller cuts off the current introduced into the induction coil, the refrigeration equipment is started and communicated with the cooling channel in the heating block, so that the temperature of the heating block is rapidly reduced, and the rapid cooling of the thermal state forming die is realized.

Preferably, the setting combination manner of the heating blocks in the second step includes any one combination manner or a plurality of concurrent combination manners of equal spacing and/or unequal spacing, equal length and/or unequal length, same shape and/or different shapes, same direction and/or different directions, same material and/or different materials, same temperature and/or different temperatures, grouping and/or not grouping.

Compared with the prior art, the invention has the following technical effects:

The split heating blocks are combined on the heat conducting plate, so that the forming die is heated, the heating device is simple to process and low in cost, and the problems of die material waste, die strength weakening, processing difficulty and the like caused by the fact that a complex groove for arranging a heating coil is directly processed on the die in the prior art are solved; the heating block can flexibly change the input heat values of different subareas on the die according to the shape of the tube blank, so that the temperature of each subarea can be quickly regulated and controlled in different gradients and subareas. The cooling channel is arranged in the heating block, so that the mold can be rapidly cooled or controllably cooled in different regions, and the problem that the mold is deformed or damaged due to the fact that the heat stress is generated by unreasonable cooling in the traditional natural cooling is avoided.

drawings

in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a heating device of a large-size thin-wall pipe forming die according to the present invention;

FIG. 2 is a first structural diagram illustrating a combination manner of heating blocks in the heating device of the large-sized thin-walled tube forming mold according to the present invention;

FIG. 3 is a second structural schematic diagram of a combination mode of heating blocks in the heating device of the large-size thin-wall pipe forming die according to the present invention;

FIG. 4 is a third schematic structural view of a combination mode of heating blocks in the heating device of the large-size thin-wall pipe forming die according to the present invention;

FIG. 5 is a fourth schematic structural view of a combination mode of heating blocks in the heating device of the large-size thin-walled tube forming mold according to the present invention;

FIG. 6 is a fifth structural schematic diagram of a combination mode of heating blocks in the heating device of the large-size thin-wall pipe forming die according to the present invention;

FIG. 7 is a sixth schematic structural view of a combination mode of heating blocks in the heating device of the large-size thin-wall pipe forming die according to the present invention;

FIG. 8 is a seventh schematic structural view of a combination of heating blocks in the heating apparatus of the large-sized thin-walled tube forming mold according to the present invention;

FIG. 9 is an eighth schematic structural view showing a combination manner of heating blocks in the heating apparatus of the large-sized thin-walled tube forming mold according to the present invention;

wherein: 1-forming die, 2-heat conducting plate, 3-heating block, 4-induction coil, 5-cooling channel, 6-temperature controller, 7-bolt, 8-pipe blank.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

The invention aims to provide a heating device and a partitioned temperature control method for a large-size thin-wall pipe fitting forming die, which are used for solving the problems in the prior art, rationalizing the heating temperature distribution in the pipe fitting forming process and realizing the quick and effective adjustment of the temperature of the forming die in the using process.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1 to 9: the embodiment provides a heating device of jumbo size thin-walled tube spare forming die, including heat-conducting plate 2, heating piece, induction coil 4 and temperature controller 6, be provided with a plurality of heating piece on the heat-conducting plate 2, the heating piece is provided with different length and shape, and the heating piece can make up out different heating regions, winds on every heating piece and is equipped with induction coil 4, and induction coil 4 is connected with temperature controller 6 electricity, and heat-conducting plate 2 is used for being connected with forming die 1.

The heating block is internally provided with cooling channels 5 with different lengths, and the cooling channels 5 are connected with refrigeration equipment through pipelines. A cooling channel 5 is arranged in the heating block, and refrigerating gas or cold water with the temperature of 5-20 ℃ is introduced into the cooling channel 5 to forcibly cool the forming die 1, so that a temperature field with larger gradient can be obtained, and the problem that the traditional fixed heating block can only heat but can not cool is avoided; the structure of the cooling channel 5 can also be arranged in individual heating blocks or local areas of the heating blocks, and after the tube blank 8 is formed, the problem that the forming die 1 is deformed or damaged easily due to thermal stress generated by unreasonable temperature reduction because the traditional fixed heating blocks can only be naturally cooled after the forming is finished can be solved.

the heating block is fixed on the heat conducting plate 2 through a bolt 7, and the induction coil 4 is a copper pipe coil. The heating block is a rectangular block, an arc block or an irregular block. The heating blocks are arranged on the heat conducting plate 2 in a combined manner of length and/or shape at variable or constant intervals according to the heating areas of different tube blanks 8. In the embodiment, the split heating blocks are combined on the heat conducting plate 2 to heat the forming die 1, so that the heating device is simple to process and low in cost, and the problems of die material waste, die strength weakening, processing difficulty and the like caused by the traditional method of directly processing a complex groove for arranging a heating coil on a die are solved; the heating block can flexibly change the input heat values of different subareas on the die according to the shape of the tube blank 8, so that the temperature of each subarea can be quickly regulated and controlled in different gradients and subareas. The upper surface of a mold with strong magnetic permeability, such as a carbon steel mold, can be directly heated by using a copper pipe coil, the upper surface of the mold can also be rapidly heated by using an induction-heatable heating block, and then the heat is transferred to the mold which can not be subjected to induction heating, so that the problem that a regular heating block and a copper coil cannot be adopted when the forming mold 1 is made of materials with strong magnetic permeability and weak magnetic permeability is solved; the forming die 1 of different materials can be heated.

the invention also relates to a partitioned temperature control method of the heating device of the large-size thin-wall pipe fitting forming die, which is based on the heating device of the large-size thin-wall pipe fitting forming die and specifically comprises the following steps:

Firstly, determining a set temperature field of the whole area of a heat conducting plate 2 on a tube blank 8 forming die 1 through a theoretical calculation method of thermodynamic simulation, obtaining the set temperature fields of sub-areas on different positions of the heat conducting plate 2, and further determining the input heat value and current value of each sub-area on the heat conducting plate 2.

And step two, designing and processing the shapes and sizes of the heating blocks and the induction coils 4 which need to be arranged on the sub-areas according to the heat input quantity of the sub-areas on the heat conduction plate 2, installing the induction coils 4 on the heating blocks, and installing the heating blocks on the corresponding positions of the sub-areas of the heat conduction plate by using bolts 7 according to a set combination mode. The setting combination mode of the heating blocks comprises any one combination mode or a plurality of coexistence combination modes in equal spacing and/or unequal spacing, equal length and/or unequal length, same shape and/or different shapes, same direction and/or different directions, same material and/or different materials, same temperature and/or different temperatures, grouping and/or not grouping. The heating block may specifically include the following common combinations:

(1) As shown in fig. 2, the heating blocks are equal in size, shape and material, regularly distributed at equal intervals, and applied to a temperature field which is relatively uniformly distributed in the longitudinal direction, so as to heat the tube blank 8 which is uniformly deformed in the longitudinal direction. (2) As shown in fig. 3, the heating blocks are equal in size, shape and material, are distributed at unequal intervals, are suitable for a temperature field with gradient (uneven) distribution in the longitudinal direction, and are used for heating the tube blank 8 which is unevenly deformed in the longitudinal direction, and the deformation amount at the bent portion of the tube blank 8 is large, so that the required heating temperature is high. (3) As shown in fig. 4, the heating blocks are the same in size, shape and material, are different in the direction of installation, are suitable for a temperature field in which the heating blocks are distributed in a gradient (uneven) manner in the longitudinal direction, and are used for heating a tube blank 8 that is not deformed uniformly in the longitudinal direction, and have a large amount of deformation at the bent portion of the tube blank 8, and the temperature to be heated is high. (4) As shown in fig. 5, the heating blocks are different in size, spacing and material, are suitable for a temperature field with gradient (uneven) distribution in the length direction, and are used for heating a tube blank 8 with uneven deformation in the length direction, and have large deformation at the bending part of the tube blank 8 and higher required heating temperature, and the heating blocks in the figure are made of 45 steel and 65Mn respectively in two different materials. (5) As shown in fig. 6, the heating blocks are different in size, shape, spacing and material, and are suitable for a temperature field with gradient (uneven) distribution in the length direction, and can heat forming dies 1 made of different materials for heating tube blanks 8 with uneven deformation in the length direction, the heating blocks in the figure are made of 45 steel and 65Mn, respectively, and the dies can be made of carbon steel or stainless steel. (6) As shown in fig. 7, the heating blocks are different in size, shape, direction, distance and temperature, the cooling channels 5 are arranged in part of the heating blocks, and cooling media are introduced into the cooling channels 5 to forcibly cool the forming die 1, so that the method is suitable for uneven complex gradient temperature fields, and can obtain temperature fields with larger gradients, the temperature difference of each heating block is 50-100 ℃, and the problem that the traditional fixed heating block can only heat and cannot cool is solved. (7) As shown in fig. 8, the heating blocks are different in size, shape, direction, distance and temperature, the cooling channel 5 is arranged in the local part of the heating block, and a cooling medium is introduced into the cooling channel 5, so that the heating block is suitable for the situation of an uneven more complex gradient temperature field, the heating block can locally cool the tube blank 8, and is suitable for an uneven more complex gradient temperature field, and the temperature difference of each heating block is 100-350 ℃. (8) As shown in fig. 9, the heating blocks are different in size, shape, direction, distance and temperature, and all the heating blocks are provided with cooling channels 5, so that the cooling device is suitable for uneven complex gradient temperature fields, and can realize forced cooling of the forming mold 1, thereby realizing rapid or controllable cooling of the entire mold. After the tube blank 8 is formed, the cooling channel 5 is arranged to avoid the problem that the conventional fixed heating block can only be naturally cooled after the forming is finished, and the forming die 1 is easily deformed or damaged due to thermal stress generated by unreasonable cooling.

And step three, introducing corresponding current values into the induction coils 4 of each sub-area through the temperature controller 6, heating the heating block, heating the heat conduction plate 2 in the sub-areas until the set time, and then cooling the forming die 1.

And step four, after the tube blank 8 is formed or the temperature controller 6 reaches a set time, the temperature controller 6 cuts off the current introduced into the induction coil 4, the refrigeration equipment is started and communicated with the cooling channel 5 in the heating block, so that the temperature of the heating block is quickly reduced, the quick cooling of the hot forming die 1 is realized, and the problems that the traditional fixed heating block can only be naturally cooled after the forming is finished, and the forming die 1 is easily deformed or damaged due to the thermal stress generated by unreasonable cooling are solved.

the principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.