CN206104625U - Device in straight flange hole is made to turning up on hollow closed part of complicated curved surface - Google Patents

Abstract

The utility model discloses a device for turning out straight-side holes on hollow closed parts with complex curved surfaces, and belongs to the technical field of precision forming of plate and tube parts. The device includes a needle roller sleeve, a needle roller and a mandrel. The mandrel is driven by the machine tool to rotate and feed axially. The rotation of the mandrel drives the needle roller sleeve and the needle roller to rotate around the mandrel. Under the action of the friction force of the mandrel and the friction force of the hole wall of the part, the self-rotation is carried out, and the needle sleeve, the needle roller and the mandrel cooperate with each other to realize the hole turning on the prefabricated bulge of the part. When turning the hole, prefabricate the bulge on the part, then gradually press the hole turning device into the prefabricated hole to turn up the material to be processed, and finally complete the hole turning process by sizing and correcting the shape. The utility model has a simple hole-turning device, which effectively reduces the technical difficulty of turning outwards a straight-side hole on a hollow closed part, and the friction force between the device and the part is small, and the hole-turning dimensional accuracy is high, which can effectively prevent the hole from turning over Cracked edges.

Description

A device for turning outwards straight-side holes on hollow closed parts with complex curved surfaces

technical field

The utility model relates to the technical field of precision forming of plate and tube parts, in particular to a device for outwardly turning straight-side holes on hollow closed parts with complex curved surfaces.

Background technique

When connecting closed tubular, plate-shaped or other shaped hollow components with other parts, it is usually necessary to turn straight-sided holes. The turned holes usually include assembly holes, positioning holes, electrophoretic paint holes, etc. This kind of parts with straight-sided holes is widely used. It is used in the fields of aviation, aerospace, nuclear power, and automobile manufacturing. For example, the subframe of an automobile is a typical hollow part, and various types of holes are turned on it to connect with other parts. Usually, internal high-pressure technology is used to form pipe fittings, and then hydraulically punched. For example, in the nuclear power industry, a plurality of outward straight-edge turning holes are processed on annular pipe fittings for subsequent welding with other components to conduct liquid medium for energy exchange.

The traditional process mainly includes direct punching with ordinary punches, progressive turning of thin-walled tubes without dies, etc. When turning holes in closed tubular or other special-shaped hollow members, ordinary punching methods are often used to directly punch holes from the outside of the pipe. Turning holes inward, but it is impossible to turn the hollow closed parts outward, and the hollow closed parts usually need to be connected with other external parts such as welding, and the outward turning hole side wall is required as the connection medium; and the turning holes of complex curved surfaces, Due to the radian and certain corners of the base surface of the hole, the strain of the material at different positions is different after the hole is turned, and the instantaneous punch directly turns the hole will cause partial cracking at the edge of the hole, which will affect the rigidity and service life of the product.

Chinese patent application CN201510167803.0 discloses a progressive hole-turning process without dies. This method uses the high-speed rotation of the tool head with a small diameter and the matching circumferential movement around the central axis of the hole-turning to achieve a local small area. The method of contact gradually forms the turning hole. This technology can form the turning hole of the complex surface that is difficult to realize by ordinary technology, but its forming efficiency is low, the movement of the forming tool is complicated, and it has high requirements for auxiliary equipment. In addition, the local asymmetric single point The contact state causes problems such as uneven force in the turning area and difficulty in guaranteeing the forming accuracy.

In addition, in the above two process methods, the friction mode between the turning device and the parts is sliding friction, the friction force is relatively large, and the friction conditions are poor, which may easily cause problems such as scratches on the inner wall of the turning hole and poor dimensional accuracy. In addition, the relatively large frictional force will be accompanied by corresponding frictional heat. The accumulation of this heat will intensify the oxidation of the side wall material of the turning hole, reduce the surface quality of the part and the corrosion resistance of the hole wall and other problems.

Utility model content

In order to solve the deficiencies in the existing technology in the hole turning process, especially when turning holes on hollow closed parts, the purpose of this utility model is to provide a method for turning outward straight-side holes on hollow closed parts with complex curved surfaces. The utility model has the advantages of simple forming device, high production efficiency, excellent forming quality and low processing difficulty.

In order to achieve the above object, the technical scheme adopted in the utility model is as follows:

A device for turning out straight-side holes on hollow closed parts with complex curved surfaces, the device is a mechanical combination structure, including needle roller sleeves, needle rollers and mandrels; wherein: the needle roller sleeves are fitted on the mandrel On the outside, four cavities evenly distributed in the circumferential direction are opened on the side wall of the needle roller sleeve, and the needle roller is placed in the cavity and the needle roller is limited; the mandrel and the needle roller The side surfaces are in contact; the mandrel is driven by the machine tool to rotate and feed axially, and the mandrel rotates to drive the needle roller sleeve and the needle to rotate around the mandrel, and at the same time, the needle roller rubs against the hole wall of the mandrel Under the action of force, the needle roller sleeve, the needle roller and the mandrel cooperate to complete the hole turning on the prefabricated bulge of the hollow closed part.

The needle roller is an integral forming structure, which is composed of the lower needle roller cylindrical section and the upper needle roller conical section. The needle roller cylindrical section is used to turn the round hole, and the needle roller conical section is used to correct the shape of the turned hole. ; When working, the side surface of the needle roller contacts with the needle roller sleeve and the mandrel to complete the rotary motion and axial feed of the device.

The mandrel is composed of two tapered sections with different cone angles, which are the mandrel cone section I and the mandrel cone section II, wherein: the mandrel cone section I is used to contact the needle roller cone section For cooperation, the tapered section II of the mandrel is used to contact and cooperate with the cylindrical section of the needle roller; the mandrel cooperates with the needle roller sleeve to realize the restriction on the needle roller.

The conical angle of the conical section of the device and the stress on the part satisfy the relationship (1):

σ _f = μσ _N (0<μ<1);

In relation (1): σ _f is the friction force between the conical section of the device and the hole wall, σ _N is the compressive stress of the conical section of the device on the hole wall, σ _s is the yield stress of the part material, and θ is the The conical angle of the conical section, μ is the coefficient of friction between the conical section of the device and the hole wall; the conical section of the device refers to the device part corresponding to the conical section II of the mandrel, and the conical section of the device The angle is the cone angle of the cone section II of the mandrel (the angle between the cone surface and the axial direction). According to the relation (1), it is limited that the axial stress on the upturned hole of the prefabricated bulge of the part is less than the yield stress of the material of the part. Collapsing hole side walls.

In the device, an annular groove is opened in the middle and upper part of the mandrel for storing lubricating oil and realizing effective lubrication of the device.

The hole turning refers to that the device and the part to be processed are contacted at four points instantaneously, and in conjunction with the high-speed rotation of the device, the device is gradually fed over time, and the hole turning process is gradually completed. The method for turning outwards a straight-side hole on a hollow closed part with a complex curved surface by using the above-mentioned device specifically includes the following steps:

(1) A prefabricated bulge that meets the requirements in structure and size is formed on a hollow closed part by means of hydroforming;

(2) According to the structural size of the prefabricated bulge and the size data of the turned hole, calculate the parameters of the cone angle of the mandrel cone section I and the mandrel cone section II, the length of the needle roller cone section, and the length of the needle roller cylinder section;

(3) Fix the parts to be turned on the workbench, and align the center of the pre-drilled hole with the axis of the mandrel;

(4) Make the mandrel of the device rotate and feed downward axially, so that the cylindrical section of the needle roller contacts the part to be processed, and gradually turn the round hole;

(5) Continue to maintain the axial feed of the hole turning device (provide axial power to the hole turning device), and after the tapered section of the needle roller is in full contact with the straight wall hole that has been turned up, keep the rotational movement of the device for 8-10s, Realize further sizing and shaping;

(6) Reversely pull the hole-turning device to make it gradually detach from the parts, complete the hole-turning process, and take out the processed parts.

In the above hole-turning process, the mandrel in the forming device is an active mechanism, and the needle roller rotates and revolves around the mandrel under the joint pressure and friction of the forming material and the mandrel. Under the action of the revolution of the needle roller, it is pushed to rotate in the same direction and at different speeds with the mandrel.

The beneficial effects of the utility model are as follows:

1. The contact state between the hole turning device and the parts in the utility model is rolling friction. Compared with the traditional sliding friction contact method, the friction state is significantly improved, which is conducive to improving the forming quality and accuracy of the inner surface of the turning hole. The method of four needle rollers being partially contacted and deformed with the part can effectively reduce the forming force required for the hole turning process, realize the effect of gradual forming, improve the force state of the deformation zone, and reduce the extra temperature caused by the full contact between the device and the part. Up effect.

2. The device of this utility model has a radially symmetrical structure, and the device is in symmetrical contact with the turning hole, which improves the defect of asymmetric contact in the traditional process, prevents the instability of the hole wall in the deformation zone during the deformation process, and improves the roundness of the turned hole and dimensional accuracy.

3. The device of the utility model has a simple structure, consisting of several parts with simple shapes, and the device has a single movement form. It only needs to provide rotational movement around the central axis and axial feed, which greatly reduces the control requirements for supporting equipment; the production efficiency is relatively low. High, the rolling friction between the turning device and the parts can be realized, and the high-speed rotary motion can be realized. With the large axial feed, the production efficiency can be further improved.

Description of drawings

Fig. 1 is the schematic diagram of the device structure of the utility model on the hollow closed parts with complex curved surfaces turning outwards to make straight-side holes; wherein: (a) front view; (b) bottom view; (c) axial sectional view, (d) core Front view of the two conical segments of the shaft.

Fig. 2 is the overall schematic view of the device of the present invention turning outwards the straight edge hole on the curved surface hollow part.

Fig. 3 is a diagram of the conditions and working principles that should be met for the outwardly turned straight wall holes on the closed complex curved hollow member with prefabricated bulges.

Fig. 4 is the process flow diagram of turning outwards on the prefabricated bulge in embodiment 1; wherein: (a) is the work step of aligning the center axis position of the turning device; (b) is the stepwise downward axial feeding of the turning device The hole turning step; (c) is the step of correcting the shape of the turning hole side wall by the hole turning device; (d) the hole turning device reversely withdraws from the surface of the processed part after forming; in Figures (a)-(d): The left and right images are cross-sectional views from different perspectives.

In the figure: 1-hole turning device; 2-prefabricated bulge; 11-needle sleeve; 12-needle; 121-needle tapered section; 122-needle cylindrical section; 13-mandrel; 131-mandrel cone Section Ⅰ; 132- mandrel tapered section Ⅱ; 3- initial blank; 4- fixture.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments. However, the present invention is not limited to the following specific embodiments.

The utility model is a device for turning outwards a straight-side hole on a hollow closed part with a complex curved surface, that is, a hole turning device 1, and its structure is shown in Figure 1. The hole turning device 1 includes a needle roller sleeve 11, a needle roller 12 and a mandrel 13; the needle roller sleeve 11 is set on the outside of the mandrel 13, and the side wall of the needle roller sleeve 11 is provided with four uniformly distributed cavities in the circumferential direction. The needle roller 12 is placed in the cavity and the needle roller 12 is limited to ensure that the needle roller can rotate around its own rotation axis during the working process, preventing the needle roller from moving back and forth along the circumferential or axial direction; the mandrel 13 is in contact with the side surface of the needle roller 12, the mandrel 13 is driven by the machine tool to rotate and feed axially, and the rotation of the mandrel 13 drives the needle roller sleeve 11 and the needle roller 12 to rotate around the mandrel (revolution ), at the same time, the needle roller 12 rotates under the action of the friction between the mandrel 13 and the hole wall of the part, and under the cooperation of the needle roller sleeve 11, the needle roller 12 and the mandrel 13, the hole turning is completed on the prefabricated bulge 2 of the part .

The needle roller is integrally formed, consisting of a lower needle roller cylindrical section 122 and an upper needle roller conical section 121, the needle roller cylindrical section 122 is used to turn round holes, and the needle roller conical section 121 is used to turn over The hole is corrected; the mandrel is the power source of the device's rotation, and the mandrel is driven by the rotation of the machine tool to generate an autorotation motion; the mandrel is composed of two tapered segments with different cone angles, which are respectively the mandrel cone Section I131 and mandrel tapered section II132, mandrel tapered section I131 is used to contact with needle roller tapered section 121, and mandrel tapered section II132 is used to contact and cooperate with needle roller cylindrical section 122; mandrel and needle roller The sleeve cooperates to realize the restriction on the needle roller. There is an annular groove in the middle and upper part of the mandrel, which is used to store lubricating oil and realize effective lubrication of the device; when the external axial force increases, the needle roller sleeve moves upward to further lock the mandrel and the needle roller, which can Realize the full contact between the mandrel and the needle roller, and complete the hole forming.

The conical angle of the conical section of the device and the stress on the part satisfy the relationship (1):

σ _f = μσ _N (0<μ<1);

In relation (1): σ _f is the friction force between the conical section of the device and the hole wall, σ _N is the compressive stress of the conical section of the device on the hole wall, σ _s is the yield stress of the part material, and θ is the The conical angle of the conical section, μ is the coefficient of friction between the conical section of the device and the hole wall; the conical section of the device refers to the device part corresponding to the conical section II of the mandrel, and the conical section of the device The angle is the cone angle of the cone section II of the mandrel (the angle between the cone surface and the axial direction). The device can realize the outward turning holes on the prefabricated bulge without being restricted by the narrow inner space of the closed hollow part, and the forming effect is remarkable. The device is in continuous point contact (instantaneous local four-point contact) with the part to be processed. Cooperating with the high-speed rotation of the device, the device is gradually fed over time to complete the gradual forming of the hole turning and finally complete the hole turning.

Using the above-mentioned device to turn outwards a straight-sided hole on a hollow closed part with a complex curved surface is shown in Figure 2. The hole turning process is as follows:

(1) Forming a prefabricated bulge with a structure and size that meets the requirements by means of hydroforming;

(2) According to the structural size of the prefabricated bulge and the size data of the turned hole, calculate the parameters of the cone angle of the mandrel cone section I and the mandrel cone section II, the length of the needle roller cone section, and the length of the needle roller cylinder section;

(3) Fix the parts to be turned on the workbench, and align the center of the pre-drilled hole with the axis of the mandrel;

(4) Make the mandrel of the device rotate and feed downward axially, so that the cylindrical section of the needle roller contacts the part to be processed, and gradually turn the round hole;

(5) Continue to maintain the axial feed of the hole turning device (provide axial power to the hole turning device), and after the tapered section of the needle roller is in full contact with the straight wall hole that has been turned up, keep the rotational movement of the device for 8-10s, Realize further sizing and shaping;

(6) Reversely pull the hole-turning device to make it gradually detach from the parts, complete the hole-turning process, and take out the processed parts.

Example 1:

In this embodiment, the workpiece to be turned is a hollow closed part, and the surface is a space curved surface structure, specifically an annular closed tube blank (Fig. 2). Before carrying out the hole turning process, with the cooperation of the appropriate internal high pressure forming process, carry out hydraulic bulging of the annular closed tube blank under the mold constraint state, prefabricate the bulge for hole turning, and keep the axis of the hole turning device 1 coincident with the hole turning axis . In order to ensure that the device can turn out the holes normally on the prefabricated bulge parts, as shown in the working principle diagram of the device for turning the holes outward on the prefabricated bulge in Figure 3, the device needs to satisfy the relational formula σ _f =μσ _N (0<μ<1 ); That is to prevent the hole from being crushed axially by the device before it is turned up, and only when there is sufficient support force component along the radial direction can the prefabricated bulge turn outward. Figure 1 is a schematic diagram of the preferred two-dimensional structure of the device of this embodiment. The device is a radially symmetrical structure. When in use, put four needle rollers 12 into the inside of the needle roller sleeve 11 from the core, and constrain its radial displacement through the needle roller restriction holes. There is sliding friction between the needle roller restriction holes and the needle rollers 12, and the oil Lubrication is provided; the mandrel 13 passes through the core of the needle roller sleeve 11, and the mandrel 13 reaches the axial limit position under the conical restriction of the needle roller sleeve 11. The two tapered sections of the mandrel 13 are connected with the four needle roller The outer surface of 12 is fully contacted, and the mandrel 13 and the upper part of the needle roller sleeve 11 are connected by threads. As shown in Figure 4, the process flow of turning the holes outward on the prefabricated bulge is first processed by hydroforming and other methods to produce a prefabricated bulge with a structure and size that meets the requirements; Calculate the key parameters of the device, mainly including the cone angle of the mandrel cone section I, the cone angle of the mandrel cone section II, the length of the needle roller cone section and the length of the needle roller cylindrical section. Hole-turning device: use the corresponding fixture 4 to fix the initial blank 3 on the workbench, adjust the equipment with the hole-turning device so that the axis of the device coincides with the axis of the hole-turning prefabricated hole; start the equipment to provide the required rotational movement of the device and axial downward feed, after the outer surface of the conical section of the device (the part where the mandrel conical section II is located) contacts the upper edge of the prefabricated bulge, properly adjust the axial feed speed, and the rotation and revolution of the needle roller 12 Under the cooperative action, the edge of the prefabricated bulge with an opening expands radially outward, and the hole turning continues; when the upper cylindrical section of the hole turning device (the part where the tapered section I of the mandrel is located) contacts the inner wall of the bulge, the axial direction stops. Feed, keep the mandrel rotating for 8-10s, and correct the inner wall of the turning hole; after the shaping is finished, turn the axial feeding direction, so that the needle roller is separated from the inner wall of the turned hole, and stop the rotation and axial movement of the device. Release the clamp to remove the machined part.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (5)

1. A device for making straight-sided holes outward on hollow closed parts with complex curved surfaces, characterized in that: the device is a mechanical combination structure, including needle roller sleeves, needle rollers and mandrels; wherein: the needle roller sleeves Set on the outside of the mandrel, four cavities evenly distributed in the circumferential direction are opened on the side wall of the needle roller sleeve, and the needle rollers are placed in the cavities and limit the needle rollers; the mandrel It is in contact with the side surface of the needle roller; the mandrel is driven by the machine tool to rotate and feed axially. Under the action of the shaft friction and the part hole wall friction, the needle roller sleeve, the needle roller and the mandrel interact to realize the outward turning of the straight edge hole on the prefabricated bulge of the hollow closed part. 2. The device for turning out straight-side holes on hollow closed parts with complex curved surfaces according to claim 1, characterized in that: the needle roller is integrally formed, and the cylindrical section of the needle roller at the lower part and the roller at the upper part Conical section of the needle roller, the cylindrical section of the needle roller is used to turn the round hole, and the tapered section of the needle roller is used to correct the shape of the turning hole; when working, the side surface of the needle roller contacts with the needle roller sleeve and the mandrel to complete the device. Rotary motion and axial feed. 3. The device for turning outwards a straight-sided hole on a hollow closed part with a complex curved surface according to claim 2, wherein the mandrel is composed of two tapered segments with different taper angles, which are respectively the core Shaft tapered section I and mandrel tapered section II, wherein: mandrel tapered section I is used for contact and fit with the needle roller tapered section, and mandrel tapered section II is used for contact and fit with the needle roller cylindrical section; The mandrel cooperates with the needle roller sleeve to realize the restriction on the needle roller. 4. The device for outwardly turning straight-side holes on hollow closed parts with complex curved surfaces according to claim 3, characterized in that: the taper angle of the tapered section of the device and the stress on the parts satisfy the relational formula (1) : σ _f = μσ _N (0<μ<1); In relation (1): σ _f is the friction force between the conical section of the device and the hole wall, σ _N is the compressive stress of the conical section of the device on the hole wall, σ _s is the yield stress of the part material, and θ is the The conical angle of the conical section, μ is the coefficient of friction between the conical section of the device and the hole wall; the conical section of the device refers to the device part corresponding to the conical section II of the mandrel, and the conical section of the device The angle is the cone angle of the cone section II of the mandrel. 5. The device for turning outwards a straight-side hole on a hollow closed part with a complex curved surface according to claim 4, characterized in that: the upper middle part of the mandrel is provided with an annular groove for storing lubricating oil to realize the device effective lubrication.