CN214976911U - Pipe bending forming die - Google Patents

Abstract

The utility model provides a tubular product bending mould, include: the device comprises a pressure die, a crease-resist die, a core die, a clamping die, a bending die and an auxiliary die; the pressure die, the crease-resist die, the clamping die, the bending die and the auxiliary die are all assembled on a machine tool; at least one of the pressure die, the crease-resistant die and the core die is provided with a refrigerating hole. The utility model discloses a scheme the mould be applicable to the taking shape of the tubular product of cryrogenic environment, can improve the bending forming limit of high-strength tubular product, the little bending radius tubular product of heavy-calibre thin wall.

Description

Pipe bending forming die

Technical Field

The utility model relates to a technical field is made to tubular product, especially indicates a tubular product bending mould.

Background

The high-strength aluminum alloy/titanium alloy thin-wall pipe has high specific strength, good corrosion resistance and welding performance, and is widely applied to hydraulic, fuel oil, environmental control and other systems of aircrafts and spacecrafts. The thin-wall, large-caliber and small-bending-radius elbow component has the advantages of weight reduction, space efficiency and the like, and plays an important role in pipeline systems of advanced airplanes.

However, the high-strength aluminum alloy/titanium alloy has low elongation and weak hardening effect, belongs to a material difficult to deform, has a large diameter-thickness ratio (D/t) of a thin-wall and large-caliber pipe, belongs to a structure difficult to form, is subjected to complex constraint of multiple dies in a bending forming process, has high bending forming difficulty, is very easy to cause uneven deformation in the forming process of the pipe made of the material/structure difficult to deform, causes various forming instability defects such as thinning and pulling cracks at the outer side of the bent pipe, instability and wrinkling at the inner side, and severely restricts the forming limit of the bending of the pipe.

Therefore, how to increase the bending forming limit of the material/structural pipe material with difficult deformation, i.e. reduce the bending radius, becomes a key problem for improving the bending manufacturing capability of the material/structural pipe member material with difficult deformation.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a tubular product bending mould. The bending forming limit of high-strength pipes and large-caliber thin-wall pipes with small bending radius can be improved.

In order to solve the technical problem, the technical scheme of the utility model as follows:

a pipe bending die comprising: the device comprises a pressure die, a crease-resist die, a core die, a clamping die, a bending die and an auxiliary die;

the pressure die, the crease-resist die, the clamping die, the bending die and the auxiliary die are all assembled on a machine tool; at least one of the pressure die, the crease-resistant die and the core die is provided with a refrigerating hole.

Optionally, at least one of the clamping die and the bending die is provided with a cooling hole.

Optionally, the mandrel comprises a mandrel and a mandrel ball; the core rod is provided with the refrigerating hole.

Optionally, the pipe bending and forming die further includes: a pressure die insulation plate; the pressure die heat insulation plate is arranged between the pressure die and the machine tool.

Optionally, the surface of the pressure mold heat insulation plate, which is in contact with the pressure mold, is serrated, a rectangular groove is formed in the surface of the pressure mold, which is in contact with the pressure mold heat insulation plate, and the serrations on the pressure mold heat insulation plate are embedded into the rectangular groove and fixed with the pressure mold.

Optionally, a space is formed between the pressure mold heat insulation plate and the pressure mold to form an air interlayer; the air interlayer is provided with an asbestos pad.

Optionally, the pipe bending and forming die further includes: and the crease-resist mold heat insulation plate is arranged between the crease-resist mold and the machine tool.

Optionally, a rectangular groove is formed in one surface, in contact with the crease-resistant mold heat insulation plate, of the crease-resistant mold, and sawteeth on the crease-resistant mold heat insulation plate are embedded into the rectangular groove and fixed with the crease-resistant mold.

Optionally, asbestos pads are laid on the upper surface of the pressure die, the upper surface of the crease-resist die, the upper surface of the bending die, the upper surface of the auxiliary die and the upper surface of the clamping die.

Optionally, the inner cavity of the core mold is coaxially assembled with the pipe to be bent.

The above technical scheme of the utility model at least include following beneficial effect:

the above technical scheme of the utility model, through the tubular product bending mold who is applicable to the cryrogenic environment, include: the device comprises a pressure die, a crease-resist die, a core die, a clamping die, a bending die and an auxiliary die; the pressure die, the crease-resist die, the clamping die, the bending die and the auxiliary die are all assembled on a machine tool; at least one of the pressure die, the crease-resistant die and the core die is provided with a refrigerating hole; pre-cooling the pipe to be bent for a preset time; mounting the pre-cooled pipe to be bent on a machine tool through the pipe bending forming die to be bent; and bending the pipe according to the preset bending control parameters of the machine tool and the preset bending parameters of the pipe. Therefore, the bending forming limit of the high-strength pipe and the large-caliber thin-wall small-bending-radius pipe is improved, the thinning, pulling crack and instability and wrinkling degrees which are easy to occur in the pipe forming process are reduced, and the key technical problem that the forming limit of the difficult-to-deform material/structural pipe is difficult to improve is solved.

Drawings

Fig. 1 is a front view of a pipe bending mold according to the present invention;

FIG. 2 is a perspective view of a pressure die of the tube bending mold shown in FIG. 1;

FIG. 3 is a front view of the pressure die of FIG. 2;

FIG. 4 is a left side view of the pressure die of FIG. 2;

FIG. 5 is a perspective view of a blank holder die of the tube bending die shown in FIG. 1;

FIG. 6 is a front view of the blank holder shown in FIG. 5;

FIG. 7 is a left side view of the blank holder shown in FIG. 5;

FIG. 8 is a perspective view of a core mold of the pipe bending mold shown in FIG. 1;

fig. 9 is an expanded view of the mandrel of fig. 8;

FIG. 10 is a perspective view of a clamp die of the tube bending mold shown in FIG. 1;

FIG. 11 is a front view of the clamp die of FIG. 10;

FIG. 12 is a left side view of the clamp die of FIG. 10;

FIG. 13 is a perspective view of a bending die of the tube bending mold shown in FIG. 1;

FIG. 14 is a front view of the bending die of FIG. 13;

FIG. 15 is a left side view of the bending die of FIG. 13;

FIG. 16 is a perspective view of an auxiliary die of the tube bending mold shown in FIG. 1;

FIG. 17 is a front view of the auxiliary die of FIG. 16;

fig. 18 is a left side view of the auxiliary die shown in fig. 16.

Description of reference numerals:

1. a pressure die; 2. a crease-resist die; 3. a core mold; 4. clamping the die; 5. a bending die; 6. an auxiliary die; 7. a pressure die insulation plate; 8. a crease-resist mould heat insulation plate; 9. and (5) refrigerating the holes.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As shown in fig. 1 to 18, an embodiment of the present invention provides a pipe bending mold, including: the device comprises a pressure die 1, a crease-resist die 2, a core die 3, a clamping die 4, a bending die 5 and an auxiliary die 6;

the pressure die 1, the crease-resist die 2, the clamping die 4, the bending die 5 and the auxiliary die 6 are all assembled on a machine tool; at least one of the pressure die 1, the crease-resist die 2 and the core die 3 is provided with a refrigeration hole. The purpose of forming the cooling holes in the press die 1, the wrinkle preventing die 2 and the core die 3 is to allow the cooling medium to cover the outer outside, the outer inside and the inner region of the bending point in all directions.

The pipe to be bent can be a pipe of a material/structure which is difficult to deform and/or a pipe which is suitable for deep cooling low-temperature forming, such as an aluminum alloy/titanium alloy pipe;

according to the embodiment, a cryogenic low-temperature bending environment of the aluminum alloy/titanium alloy thin-wall pipe is created through a pipe pre-cooling and bending forming die cryogenic low-temperature cooling channel, and cryogenic low-temperature forming is achieved. The double-effect of material strength and plasticity at low temperature can be utilized to avoid the forming defects of thinning and cracking of the outer side and wrinkling of the inner side of the bent pipe, and the like, and improve the uniformity of pipe deformation, thereby solving the key technical problem that the forming limit of the aluminum alloy/titanium alloy thin-walled pipe is difficult to improve.

The utility model discloses an in the optional embodiment, suitable aluminum alloy thin wall pipe specification is: the wall thickness is 0.7 mm-1.5 mm, D/t (outer diameter/wall thickness) is 45-60, and the lowest bending radius can reach 1.2D.

The utility model discloses an in the optional embodiment, the titanium alloy thin wall pipe specification that is suitable for is: the thickness of the wall is 0.5 mm-1.5 mm, D/t (outer diameter/wall thickness) is 12-71, and the minimum relative bending radius can reach 0.9D.

In the optional embodiment of the utility model, the heat treatment state of the applicable aluminum alloy thin-wall tube is one of T4, T6 and O state.

In an alternative embodiment of the invention, at least one of the clamping die 4 and the bending die 5 is provided with a cooling hole 9. The purpose of forming the cooling holes in the clamping die 4 and the bending die 5 is to allow the cooling medium to cover the outer outside, the outer inside, and the inner region of the bending tangential point in all directions.

In an alternative embodiment of the present invention, the core mold 3 includes a core rod and a core ball; the core rod is provided with the refrigerating hole 9.

The utility model discloses an in the optional embodiment, the crooked forming die of tubular product still includes: a pressure die insulation plate 7; the pressure die heat insulation plate 7 is arranged between the pressure die 1 and a machine tool.

The utility model discloses an optional embodiment, pressure die thermal insulation board 7 with the surface of pressure die 1 contact is the cockscomb structure, pressure die 1 with the rectangular channel has been opened to the one side of pressure die thermal insulation board 7 contact, in the sawtooth embedding rectangular channel on the pressure die thermal insulation board 7 with pressure die 1 is fixed. The purpose of positioning and fixing the pressure die heat insulation plate 7 and the pressure die 1 is achieved.

In the optional embodiment of the present invention, there is a gap between the pressure mold heat insulation plate 7 and the pressure mold 1 to form an air interlayer; the air interlayer is provided with an asbestos pad.

The utility model discloses an in the optional embodiment, the crooked forming die of tubular product still includes: and the crease-resist mold heat insulation plate 8 is arranged between the crease-resist mold 2 and the machine tool.

The utility model discloses an optional embodiment, the one side of crease-resistance mould 2 and the contact of crease-resistance mould thermal-insulation board 8 is opened there is the rectangular channel, sawtooth on crease-resistance mould thermal-insulation board 8 imbed in the rectangular channel with crease-resistance mould 2 is fixed. The purposes of positioning and fixing the crease-resist die 2 and the crease-resist die heat insulation plate 8 are achieved.

The utility model discloses an in the optional embodiment, the upper surface of pressure mould 1 the upper surface of crease-resistance mould 2 the upper surface of bending die 5 the upper surface of supplementary mould 6 and the upper surface of centre gripping mould 4 has all been laid and has been covered the asbestos pad.

In an alternative embodiment of the present invention, the inner cavity of the core mold 3 is coaxially assembled with the pipe to be bent. The core mould 3 is assembled inside the pipe to play a supporting role.

The utility model discloses an embodiment the tubular product bending mould be applied to in foretell tubular product bending method, the bending limit that has improved high strength tubular product, the little bending radius tubular product of heavy-calibre thin wall can avoid the crooked outside attenuate fracture of tubular product and inboard shaping defects such as corrugating, promotes the homogeneity that tubular product warp to the key technical problem that the shaping limit of aluminum alloy titanium alloy thin wall pipe is difficult to improve has been solved.

When the pipe is bent by using the pipe bending forming die, the pipe bending forming method comprises the following steps:

step 11, providing a pipe bending forming die suitable for a cryogenic environment;

step 12, pre-cooling the pipe to be bent for a preset time; here, the pipe to be bent may be a pipe of a material/structure that is difficult to deform and/or a pipe suitable for cryogenic low-temperature forming, such as an aluminum alloy/titanium alloy pipe;

step 13, mounting the pre-cooled pipe to be bent on a machine tool to be bent through the pipe bending forming die;

and 14, bending and forming the pipe according to the preset bending control parameters of the machine tool and the preset bending parameters of the pipe.

According to the embodiment, a cryogenic low-temperature bending environment of the aluminum alloy/titanium alloy thin-wall pipe is created through a pipe pre-cooling and bending forming die cryogenic low-temperature cooling channel, and cryogenic low-temperature forming is achieved. The double-effect of material strength and plasticity at low temperature can be utilized to avoid the forming defects of thinning and cracking of the outer side and wrinkling of the inner side of the bent pipe, and the like, and improve the uniformity of pipe deformation, thereby solving the key technical problem that the forming limit of the aluminum alloy/titanium alloy thin-walled pipe is difficult to improve.

In an optional embodiment of the present invention, step 12 may include:

and placing the pipe to be bent into a heat preservation chamber filled with a cooling medium, and cooling the pipe according to the pre-cooling temperature for the preset time, wherein the preset time is adjusted according to the wall thickness of the pipe and the cooling temperature.

Specifically, the pipe to be bent is placed into a heat preservation chamber filled with liquid nitrogen, and is cooled and preserved for 10 minutes to ensure the precooling of the bent pipe.

In an optional embodiment of the present invention, the preset bending parameters of the pipe include: presetting a bending forming temperature, wherein the pre-cooling temperature is lower than the bending forming temperature, and the preset bending forming temperature is lower than a preset value.

The preset bending control parameters of the machine tool comprise: the bending speed of the bending die of the pipe bending forming die, the boosting speed of the pressure die of the pipe bending forming die and the bending angle of a machine tool. Here, the pipe bending forming die is assembled on a machine tool and drives the pressure die to move, and the boosting speed of the pressure die is the speed of the pressure die translating under the driving of the bending speed of the machine tool.

In an optional embodiment of the present invention, step 14 may include:

and under the control of the bending speed and the pressure die boosting speed, bending and forming the pipe under the control of a preset bending and forming temperature according to the bending speed of a machine tool and a set bending angle.

During specific implementation, lubricating grease is smeared in an inner cavity of a pipe bending forming die, the cooled pipe is installed on a machine tool, a refrigerating hole channel in the die is opened for 2 minutes, and the initial deep cooling low-temperature state of the pipe is guaranteed. And bending the pipe under the control of a preset bending temperature according to the bending speed of the machine tool and the boosting speed of a pressure die of the pipe bending forming die and the bending speed of the machine tool and the set bending angle.

The utility model discloses an optional embodiment, under the control of predetermineeing the bending temperature, it is right tubular product carries out bending and takes shape and includes:

introducing a cooling medium into a cooling hole of at least one of a pressure die, a crease-resist die, a core die, a clamping die and a bending die of the pipe bending forming die, so that the cooling medium covers the region of a bending tangent point of the pipe;

and controlling the temperature of the region of the bending tangent point to be within a next preset range above and below the preset bending forming temperature, and bending and forming the pipe.

Optionally, the temperature of the region of the bend tangent point is controlled by adjusting the discharge rate of the cooling medium.

Specifically, the temperature of the region of the bending tangent point is controlled within a preset range above and below the preset bending forming temperature, and the pipe is bent and formed;

and after the pipe is bent and formed, closing the cooling medium, and taking down the pipe after the pipe is restored to the room temperature. Here, the cooling medium may be one of liquid nitrogen, liquid helium, or liquid helium.

In this embodiment, the purpose of forming the cooling holes in the press die, the wrinkle preventing die, and the core die is to allow the cooling medium to cover the outer outside, the outer inside, and the inner region of the bending tangent point in all directions;

in the embodiment, the adopted temperature measuring method is to measure the temperature of the bending tangent point and the nearby area in real time by using a non-contact laser thermometer, and the temperature control is realized by adjusting the liquid nitrogen discharge speed, so that the bending tangent point and the nearby area are always kept in a certain temperature range.

Optionally, cooling holes can be formed in the clamping die and the bending die to enhance the cooling effect, especially under the condition that lower bending forming temperature is needed.

In the above embodiments of the present invention, the bending temperature is selected according to the specification of the pipe and the bending radius, generally, for the aluminum alloy thin-walled pipe, the pre-cooling temperature should be lower than-60 ℃, and the bending temperature should be lower than-50 ℃; when the D/t is more than 60 or the bending radius is less than 1.5D, the pre-cooling temperature can be lower than-200 ℃, and the bending forming temperature can be lower than-180 ℃; for the titanium alloy thin-walled tube, the pre-cooling temperature is lower than-120 ℃, and the bending forming temperature is lower than-100 ℃; when the D/t is more than 60 or the bending radius is less than 1.5D, the pre-cooling temperature can be lower than-190 ℃, and the bending forming temperature can be lower than-170 ℃.

The concrete implementation of the above embodiment of the present invention is described below, and the method for forming the aluminum alloy/titanium alloy thin-walled tube by cryogenic low-temperature bending comprises:

step one, the heat insulation between a pipe bending forming die and a machine tool: installing a pressure die heat insulation plate and a crease-resist die heat insulation plate;

secondly, assembling and debugging the die, and uniformly spraying a layer of graphite lubricant on the crease-resist die, the core rod and the core ball;

thirdly, setting the bending speed of the machine tool, the boosting speed of the pressure die during bending and the bending angle;

fourthly, setting a pre-cooling temperature and a bending forming temperature according to the material and the specification of the pipe to be bent;

fifthly, placing the pipe to be bent into a heat preservation chamber filled with liquid nitrogen, cooling and preserving heat for 10 minutes according to the set pre-cooling temperature, and adjusting the heat preservation time according to the wall thickness of the pipe and the cooling temperature;

sixthly, coating lubricating grease on the inner cavity of the die, mounting the cooled pipe on a machine tool to be bent, and measuring the temperature of the pipe by using a laser thermometer;

step seven, installing a cooling device: introducing liquid nitrogen into the cooling holes of the pressure die, the crease-resist die and the core die, and measuring the temperature until the bending tangent point reaches the set temperature;

eighthly, performing numerical control bending forming on the pipe under the cryogenic low-temperature environment, monitoring the temperature at a bending tangent point, and adjusting the liquid nitrogen discharge speed to control the temperature within a certain range above and below the bending forming temperature;

and ninthly, closing the liquid nitrogen after the bending forming is finished, and taking down the pipe after the pipe is restored to the room temperature.

The above embodiment of the utility model, will on the lathe was installed to the crooked forming die of tubular product, when the tubular product numerical control was around curved, the deformation took place in crooked tangent point department, consequently need guarantee crooked tangent point department and keep cryrogenic low temperature state all the time.

And in the bending process, a laser thermodetector is used for measuring the temperature of the bending tangent point and the area nearby the bending tangent point, the liquid nitrogen discharge speed is adjusted according to the measured temperature, and the temperature of the bending tangent point is controlled within a certain range.

The above embodiment of the utility model, ingenious design refrigeration hole on conventional bending die leads to the liquid nitrogen to crooked tangent point and near region, obtains effective cryrogenic low temperature environment for thin wall pipe bending deformation is more even.

The utility model discloses an aluminum alloy/titanium alloy thin wall pipe numerical control cryrogenic low temperature bending forming method of embodiment, compare complicated forming device, the utility model discloses it is more high-efficient, and the tubular product performance can not receive the influence of factors such as bending device and technology, and the aluminum alloy thin wall pipe that takes shape warp evenly and the performance is excellent; for the application of aluminum alloy component cryogenic low-temperature forming, the application is mostly concentrated on plate components, and no research and application related to the cryogenic low-temperature bending forming of aluminum alloy or titanium alloy thin-wall pipes are found. The problems of easy thinning, pulling crack, instability, wrinkling and the like in the deep-cooling limit bending forming process of the material/structural pipe difficult to deform are solved.

The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A pipe bending die, comprising: the anti-crease mould comprises a pressure mould (1), an anti-crease mould (2), a core mould (3), a clamping mould (4), a bending mould (5) and an auxiliary mould (6);

the pressure die (1), the crease-resist die (2), the clamping die (4), the bending die (5) and the auxiliary die (6) are all assembled on a machine tool; at least one of the pressure die (1), the crease-resist die (2) and the core die (3) is provided with a refrigeration hole.

2. Tube bending mould according to claim 1, wherein at least one of the clamping die (4) and the bending die (5) is provided with a cooling hole (9).

3. The pipe bend forming die according to claim 1 or 2, wherein the core die (3) comprises a core rod and a core ball; the core rod is provided with the refrigerating hole (9).

4. The pipe bending die according to claim 1 or 2, further comprising: a pressure die heat insulation plate (7); the pressure die heat insulation plate (7) is arranged between the pressure die (1) and a machine tool.

5. The pipe bending forming die according to claim 4, wherein the surface of the pressure die heat insulation plate (7) contacting the pressure die (1) is serrated, a rectangular groove is formed in the surface of the pressure die (1) contacting the pressure die heat insulation plate (7), and the serrations on the pressure die heat insulation plate (7) are embedded into the rectangular groove and fixed with the pressure die (1).

6. The pipe bending forming die according to claim 5, wherein the pressure die insulation plate (7) is spaced from the pressure die (1) to form an air interlayer; the air interlayer is provided with an asbestos pad.

7. The pipe bending die according to claim 1 or 2, further comprising: the anti-wrinkling mould heat insulation plate (8) is arranged between the anti-wrinkling mould (2) and the machine tool.

8. The pipe bending forming die according to claim 7, wherein a rectangular groove is formed on the surface of the crease-resist die (2) contacting with the crease-resist die insulation board (8), and sawteeth on the crease-resist die insulation board (8) are embedded into the rectangular groove and fixed with the crease-resist die (2).

9. The pipe bending mould according to claim 1, wherein the upper surfaces of the pressure die (1), the crease-resist die (2), the bending die (5), the auxiliary die (6) and the clamping die (4) are coated with asbestos pads.

10. Pipe bending mould according to claim 1, wherein the inner cavity of the core mould (3) is coaxially fitted with the pipe to be bent.

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