A double-ring roller inner contact spinning method for a tubular workpiece

Abstract

The invention discloses a double-ring roller inner contact rolling method for a tubular workpiece, which is specifically operated according to the following steps: a tubular blank to be processed is sleeved on a core mold, so that the core mold and the central axis of the tubular blank coincide; the ring-shaped cylindrical mold begins to rotate in the same direction, and the core mold is fed along the central axis direction; the tubular blank enters the first ring-shaped cylindrical mold, and the tubular blank is preliminarily rolled, and the unprocessed end is processed into a semi-finished end; the semi-finished end of the tubular blank enters the second ring-shaped cylindrical mold, and is rolled again, and the semi-finished end is processed into a finished product. The ring-shaped cylindrical mold rolling method of the invention adopts the inner surface of the mold and the outer surface of the tubular workpiece for rolling processing, and the working surface is the inner arc annular surface of the ring-shaped cylindrical mold, and the deformation zone in contact with the tubular blank has a larger wrap angle, the material has a smaller circumferential deformation and radial deformation rate, and at the same time has a larger metal axial elongation, which is an economical and rapid forming technology for thin-walled rotating body parts.

Description

Technical Field

[0001] The invention relates to the technical field of spinning and rolling forming, in particular to a double-ring roller inner contact spinning method for a tubular workpiece. Technical Background

[0002] The spinning or rolling technology of tubular workpieces generally rotates the die to make the metal stress position change from point to line, from line to surface, and at the same time applies a certain pressure in a certain direction to make the metal material deform and flow along this direction to form a set shape. Existing spinning machines and rolling mills are mostly in contact between the outer surface of the deformation die and the outer surface of the workpiece. The contact angle of the rotating wheel or roller and the blank of the tubular workpiece in the deformation zone is small, which is easy to produce defects such as longitudinal cracks and obvious ripples on the surface. Summary of the invention

[0003] The purpose of the present invention is to provide a double-ring roller inner contact spinning method for a tubular workpiece to solve the problems existing in the above-mentioned prior art, and to achieve a large axial elongation of the metal at the same time, which is an economical and rapid forming technology for thin-walled rotating parts.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a method for contact rolling of a tubular workpiece by double-ring rollers, which is specifically operated according to the following steps:

[0005] Step 1, sleeve the tubular blank to be processed on the mandrel, so that the central axis of the mandrel and the tubular blank coincide;

[0006] Step 2, the first cylindrical mold and the second cylindrical mold start to rotate in the same direction, and the core mold is fed along the central axis direction; the tubular blank enters the first cylindrical mold; the first annular curved surface of the first cylindrical mold contacts the outer surface of the tubular blank, and is pressed radially into the tubular blank, and the pressing depth forms a thinning amount Δt1; the tubular blank is preliminarily spin-rolled to process the unprocessed end into a semi-finished end;

[0007] Step 3, the semi-finished end of the tubular blank is placed into a second annular cylindrical mold, the second annular curved surface of the second annular cylindrical mold contacts the outer surface of the tubular blank, and is pressed radially into the tubular blank, the pressing depth forms a thinning amount Δt2; the tubular blank is spin-rolled again to process the semi-finished end into a finished end;

[0008] Step 4: passing the tubular blank through the first ring-shaped cylindrical mold and the second ring-shaped cylindrical mold in sequence to complete spin rolling.

[0009] Preferably, the common central axis of the tubular blank and the core mold is set to X1, and the axes of the first annular cylindrical mold and the second annular cylindrical mold are X21 and X22 respectively.

[0010] Preferably, the outer diameter of the unprocessed end of the tubular blank is D1, the outer diameter of the semi-finished end of the tubular blank is D2, and the outer diameter of the finished end of the tubular blank is D3, and the relationship between the outer diameters is D1≥D2≥D3.

[0011] Preferably, the first annular cylindrical mold and the second annular cylindrical mold are both annular rollers.

[0012] Preferably, step 2 and step 3 can be performed simultaneously after the thinning amount Δt is formed in step 1, and there is no order of precedence.

[0013] The preliminary rolling in step 2 is specifically as follows: the first annular curved surface and the contact surface of the tubular blank form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank, a three-dimensional rolling coordinate system I is established with the foot of the perpendicular O1 as the origin and the central axis of the tubular blank as the x-axis; the z-axis and the contact maximum point form a processing angle α1;

[0014] The first annular cylindrical mold is rotated in space, and the projection angle of the central axis of the first annular cylindrical mold on the x-axis of the three-dimensional rolling coordinate system I forms an adjustment angle β1, and the projection angle on the z-axis forms a feed angle γ1.

[0015] The re-spinning in step 3 is specifically as follows: the second annular curved surface and the contact surface of the tubular blank form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank, a three-dimensional spin-rolling coordinate system II is established with the foot of the perpendicular O2 as the origin and the central axis of the tubular blank as the x-axis; the z-axis and the contact maximum point form a processing angle α2;

[0016] The second annular cylindrical mold is rotated in space, and the projection angle of the central axis of the second annular cylindrical mold on the x-axis forms an adjustment angle β2, and the projection angle on the z-axis forms a feed angle γ2.

[0017] The minimum inner diameter d1 of the first annular curved surface must satisfy: the smaller of d1·cosβ1 and d1·cosγ1 is greater than the outer diameter of the unprocessed end of the tubular blank.

[0018] The minimum inner diameter d2 of the second annular curved surface must satisfy: the smaller of d2·cosβ2 and d2·cosγ2 is greater than the outer diameter of the semi-finished end of the tubular blank.

[0019] The lowest contact points formed by radially pressing the first annular cylindrical mold and the second annular cylindrical mold into the tubular blank are coplanar with the central axis of the tubular blank and are located on both sides of the central axis of the tubular blank.

[0020] The processing angle α1 is 10°-40°; the adjustment angle β1 is ±20°; and the feed angle γ1 is ±5°.

[0021] The processing angle α2 is 10°-40°; the adjustment angle β2 is ±20°; and the feed angle γ2 is ±5°.

[0022] Preferably, the adjustment angles β1, β2 and the feed angles γ1, γ2 can move in the same direction or rotate in the opposite direction; the machining angles α1, α2 and the adjustment angles β1, β2 have the same adjustment direction and are adjusted in the direction that shortens the axial distance of the lowest contact point along X1;

[0023] Preferably, the γ1 and γ2 rotate in opposite directions relative to the axis X1.

[0024] The present invention discloses the following technical effects: 1. The present invention adjusts the spin-rolling process parameters by simultaneously or individually changing the thinning amount Δt, the adjustment angle β and the feed angle γ.

[0025] 2. By changing the adjustment angle β and the feed angle γ, the annular cylindrical die can be placed in an inclined state relative to the tube blank. The angle range of the annular cylindrical die and the tube-shaped blank rolling deformation zone is adjustable, and an axial component velocity and thrust that helps the flow of metal materials is generated, thereby improving the metal flow capacity, reducing deformation resistance and stress on dangerous sections; it can avoid defects such as metal accumulation, diameter expansion, tube bending, longitudinal cracks and obvious ripples on the surface that are often caused by the general external wheel spinning method.

[0026] 3. In the working state of the present invention, the tubular blank and the core mold are axially fed relative to the annular cylindrical mold along the center line direction of the tubular blank. The deformation area of ​​the annular cylindrical blank is the inner containing surface of the annular rotating wheel, which makes it difficult for the material to produce additional circumferential deformation. At the same time, compared with the external contact rolling method, its contact deformation area is increased, the rolling force is increased, and the rolling penetration is enhanced.

[0027] 4. The use of two annular rollers can achieve two consecutive spin rollings, improving production efficiency; at the same time, the two lowest contact points are coplanar and located on both sides of the rolling center line, which is conducive to offsetting the radial force of a single die on the tubular workpiece and the lateral moment of its accessories. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1It is a schematic diagram of the structural arrangement of the initial state of the present invention.

[0030] Figure 2 It is a schematic diagram of the working state of the first embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the processing angles α1 and α2 in the first embodiment of the present invention.

[0032] Figure 4 It is a schematic diagram of the structural arrangement of the second embodiment of the present invention.

[0033] Figure 5 It is a schematic diagram of the projection of the adjustment angles β1 and β2 on the xy plane according to the second embodiment of the present invention.

[0034] Figure 6 It is a schematic diagram of the projection of the feeding angles γ1 and γ2 on the yz plane according to the second embodiment of the present invention.

[0035] Figure 7 It is a schematic diagram of the structural arrangement of embodiment 3 of the present invention.

[0036] Among them, 1-core mold, 2-tube-shaped blank, 31-first ring-shaped cylindrical mold, 32-second ring-shaped cylindrical mold, 311-first annular curved surface, 321-second annular curved surface, d1-inner diameter of the first annular curved surface, d2-inner diameter of the second annular curved surface, α1, α2-machining angle, β1, β2-adjustment angle, γ1, γ2-feeding angle, X1-axis between core mold and tube-shaped blank, X21-axis of first ring-shaped cylindrical mold and X22-axis of second ring-shaped cylindrical mold; DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] The present invention provides a method for double-ring roller inner contact spinning of a tubular workpiece, which is specifically operated according to the following steps:

[0040] Step 1: sleeve the tubular blank 2 to be processed on the core mold 1 so that the central axes of the core mold 1 and the tubular blank 2 coincide with each other;

[0041] Step 2, the first annular cylindrical mold 31 and the second annular cylindrical mold 32 start to rotate in the same direction, and the core mold 1 is fed along the central axis direction; the tubular blank 2 enters the first annular cylindrical mold 31; the first annular curved surface 311 of the first annular cylindrical mold 31 contacts the outer surface of the tubular blank 2, and is pressed in radially along the tubular blank 2, and the pressing depth forms a thinning amount Δt1; the tubular blank 2 is preliminarily spin-rolled to process the unprocessed end into a semi-finished end;

[0042] Step 3, the semi-finished end of the tubular blank 2 is placed into the second annular cylindrical mold 32, the second annular curved surface 321 of the second annular cylindrical mold 32 contacts the outer surface of the tubular blank 2, and is pressed radially into the tubular blank 2, and the pressing depth forms a thinning amount Δt2; the tubular blank 2 is spin-rolled again to process the semi-finished end into a finished end;

[0043] Step 4: The tubular blank 2 is passed through the first ring-shaped cylindrical mold 31 and the second ring-shaped cylindrical mold 32 in sequence to complete the spin rolling.

[0044] The preliminary rolling in step 2 is specifically as follows: the first annular curved surface 311 and the contact surface of the tubular blank 2 form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank 2, a three-dimensional rolling coordinate system I is established with the foot of the perpendicular O1 as the origin and the central axis of the tubular blank 2 as the x-axis; the z-axis and the contact maximum point form a processing angle α1;

[0045] The first ring-shaped cylindrical mold 31 is rotated in space, and the projection angle of the central axis of the first ring-shaped cylindrical mold 31 on the x-axis of the three-dimensional rolling coordinate system I forms an adjustment angle β1, and the projection angle on the z-axis forms a feed angle γ1.

[0046] The re-spinning in step 3 is specifically as follows: the second annular curved surface 321 and the contact surface of the tubular blank 2 form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank 2, a three-dimensional spin-rolling coordinate system II is established with the foot of the perpendicular O2 as the origin and the central axis of the tubular blank 2 as the x-axis; the z-axis and the contact maximum point form a processing angle α2;

[0047] The second annular cylindrical mold 32 is rotated in space, and the projection angle of the central axis of the second annular cylindrical mold 32 on the x-axis forms an adjustment angle β2, and the projection angle on the z-axis forms a feed angle γ2.

[0048] The minimum inner diameter d1 of the first annular curved surface 311 must satisfy: the smaller of d1·cosβ1 and d1·cosγ1 is greater than the outer diameter of the unprocessed end of the tubular blank 2 .

[0049] The minimum inner diameter d2 of the second annular curved surface 321 must satisfy: the smaller of d2·cosβ2 and d2·cosγ2 is greater than the outer diameter of the semi-finished end of the tubular blank 2 .

[0050] The lowest contact points formed by radially pressing the first annular cylindrical mold 31 and the second annular cylindrical mold 32 into the tubular blank 2 are coplanar with the central axis of the tubular blank 2 and are located on both sides of the central axis of the tubular blank 2 respectively.

[0051] The processing angle α1 is 10°-40°; the adjustment angle β1 is ±20°; and the feed angle γ1 is ±5°.

[0052] The processing angle α2 is 10°-40°; the adjustment angle β2 is ±20°; and the feed angle γ2 is ±5°.

[0053] In the embodiment of the present invention, the outer dimension of the core mold 1 is selected to be The outer dimensions of the tube-shaped blank 2 are the outer diameter Wall thickness 3.5mm, inner diameter The minimum diameter of the first annular curved surface 311 and the second annular curved surface 321 The processing angle α1=α2=30°. The processing parameters are: the feeding speed v of the tube-shaped blank 2=2 mm / s, the rotation speed n of the first ring-shaped cylindrical mold 31 and the second ring-shaped cylindrical mold 32=100 rpm, and they rotate in the same direction.

[0054] Embodiment 1 of the present invention, as Figure 2 As shown, it is the initial feeding state, the adjustment angle β1=β2=0, the feed angle γ1=γ2=0; the inner surface of the tubular blank 2 is sleeved on the outer surface of the core mold 1, and the first annular surface 311 and the second annular surface 321 embrace the outer surface of the tubular blank 2 and form an inner contact with it.

[0055] The first annular curved surface 311 and the second annular curved surface 321 are respectively pressed into the outer surface of the unprocessed end blank and the outer surface of the semi-finished end of the tubular blank 2 along the radial direction of the tubular blank 2, and the pressing depth forms the thinning amount Δt1 and Δt2. The contact points of the first annular curved surface 311 and the second annular curved surface 321 with the tubular blank 2 closest to the axis X1 are set to 21 and 22 respectively, and the farthest contact points are set to 211 and 221 respectively; the contact points 21 and 22 are coplanar with the axis X1 and are respectively located on both sides of the axis X1; perpendicular lines are drawn from the contact points 21 and 22 to the axis X1, and the feet of the perpendiculars are respectively O1 and O2, and O1 and O2 are respectively used as the origin, and the axis X1 is used as the x-axis to establish a three-dimensional rotary rolling coordinate system I and a three-dimensional rotary rolling coordinate system II, and the angles formed by points 21 and 211, points 22 and 221 with points O1 and O2 as vertices are processing angles α1 and α2 respectively;

[0056] In the rolling working state, the following two relative changes occur relative to the initial state: 1) The tubular blank 2 and the core mold 1 remain stationary, and the contact points 21 and 22 adjust the thinning amounts Δt1 and Δt2 along the radial direction of the tubular workpiece blank 2 simultaneously or separately; 2) With the contact points 21 and 22 as support points, the first ring-shaped cylindrical mold 31 and the second ring-shaped cylindrical mold 32 rotate in space simultaneously or separately, and their axes X21 and X22 form adjustment angles β1 and β2 with the x-axis projection angles in the three-dimensional rolling coordinate system I and the three-dimensional rolling coordinate system II, and form feed angles γ1 and γ2 with the z-axis projection angles in the three-dimensional rolling coordinate system I and the three-dimensional rolling coordinate system II. The above relative change processes 1) and 2) have no order of precedence.

[0057] The tubular blank 2 is rolled by a tubular die to form a finished product with a thinned finished end.

[0058] In the second embodiment of the present invention, the annular cylindrical mold is an annular rotating wheel; Figure 4 As shown in the figure, the adjustment angle β1=β2=10°, the feed angle γ1=γ2=0.5°; wherein the adjustment angles β1 and β2 rotate in the same direction as the feed angles γ1 and γ2; the first annular curved surface 311 and the second annular curved surface 321 are pressed into the outer surface of the tubular blank 2, and the pressing depth is the initial thinning amount Δt1=0.9mm, Δt1=0.6mm, and the two form an inner contact state. The core mold 1 and the tubular blank 2 actively rotate around their axis X1 and perform axial feeding along X1, as shown in FIG. Figure 6 After the tubular workpiece blank 2 contacts the first annular curved surface 311 and the second annular curved surface 321 , the first annular rotating wheel 31 and the second annular rotating wheel 32 are driven to rotate around the axes X21 and X22 respectively.

[0059] In the third embodiment of the present invention, the cylindrical mold is a circular rotating wheel; Figure 7 As shown in the figure, the adjustment angles β1 = 10°, β2 = -10°, the feed angles γ1 = 0.5°, γ2 = -0.5°; wherein the adjustment angles β1, β2 and the feed angles γ1, γ2 rotate in the opposite direction; the annular curved surface is pressed into the outer surface of the tubular workpiece blank 2, and the pressing depth is the initial thinning amount Δt1 = 0.9mm, Δt1 = 0.6mm, and the two form an internal contact state. The core mold 1 and the tubular blank 2 are axially fed along the axis X1, as shown in FIG. Figure 7 In the direction of the arrows, the annular cylindrical molds 31, 32 actively rotate around their axes X21, X22. After the tubular workpiece blank 2 contacts the inner arc surfaces 311, 321 of the annular rotating wheel, the tube blank 2 and the core mold 1 are driven to rotate around their axis X1.

[0060] The ring-cylindrical die spinning method provided by the present invention uses the inner surface of the die and the outer surface of the tubular workpiece for spinning processing. The working surface is the inner arc ring surface of the ring-cylindrical die, and the deformation zone in contact with the tubular blank has a larger wrap angle. The material has a smaller circumferential deformation and radial deformation rate, and at the same time has a larger axial elongation of the metal. It is an economical and rapid forming technology for thin-walled rotating parts.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for contact rolling of a tubular workpiece by double-ring rollers, characterized in that: Please follow the steps below: Step 1: sleeve a tubular blank (2) to be processed onto a core mold (1) so that the central axes of the core mold (1) and the tubular blank (2) coincide with each other; Step 2, the first annular cylindrical mold (31) and the second annular cylindrical mold (32) start to rotate in the same direction, and the core mold (1) is fed along the central axis direction; the tubular blank (2) enters the first annular cylindrical mold (31); the first annular curved surface (311) of the first annular cylindrical mold (31) contacts the outer surface of the tubular blank (2), and is pressed in radially along the tubular blank (2), and the pressing depth forms a thinning amount Δt1; The tube-shaped blank (2) is subjected to preliminary spin rolling to process the unprocessed end into a semi-finished end; The preliminary rolling is specifically as follows: the first annular curved surface (311) and the contact surface of the tubular blank (2) form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank (2), a three-dimensional rolling coordinate system I is established with the foot of the perpendicular O1 as the origin and the central axis of the tubular blank (2) as the x-axis; the z-axis and the contact maximum point form a processing angle α1; The first annular cylindrical mold (31) is rotated in space, and the projection angle of the central axis of the first annular cylindrical mold (31) on the x-axis of the three-dimensional rolling coordinate system I forms an adjustment angle β1, and the projection angle on the z-axis forms a feed angle γ1; Step 3, the semi-finished end of the tubular blank (2) is placed into a second annular cylindrical mold (32), the second annular curved surface (321) of the second annular cylindrical mold (32) contacts the outer surface of the tubular blank (2), and is pressed radially into the tubular blank (2), the pressing depth forming a thinning amount Δt2; the tubular blank (2) is spin-rolled again to process the semi-finished end into a finished end; Step 4: The tubular blank (2) is passed through the first annular cylindrical mold (31) and the second annular cylindrical mold (32) in sequence to complete spin rolling.

2. The method for double-ring roller inner contact rolling of a tubular workpiece according to claim 1, characterized in that: The re-spinning in step 3 is specifically as follows: the second annular curved surface (321) and the contact surface of the tubular blank (2) form a contact minimum point and a contact maximum point, a perpendicular line is drawn from the contact minimum point to the central axis of the tubular blank (2), a three-dimensional spin-rolling coordinate system II is established with the foot of the perpendicular O2 as the origin and the central axis of the tubular blank (2) as the x-axis; the z-axis and the contact maximum point form a processing angle α2; The second annular cylindrical mold (32) is rotated in space, and the projection angle of the central axis of the second annular cylindrical mold (32) on the x-axis forms an adjustment angle β2, and the projection angle on the z-axis forms a feed angle γ2.

3. The method for rolling a tubular workpiece with double-ring rollers in contact with each other according to claim 1, characterized in that: The minimum inner diameter d1 of the first annular curved surface (311) must satisfy the following requirement: the smaller of d1·cosβ1 and d1·cosγ1 is greater than the outer diameter of the unprocessed end of the tubular blank (2).

4. The method for rolling a tubular workpiece with double-ring rollers in contact with each other according to claim 2, characterized in that: The minimum inner diameter d2 of the second annular curved surface (321) must satisfy the following requirement: the smaller of d2·cosβ2 and d2·cosγ2 is greater than the outer diameter of the semi-finished end of the tubular blank (2).

5. The method for rolling a tubular workpiece with double-ring rollers in contact with each other according to claim 1, characterized in that: The lowest contact points formed by the radial pressing of the first annular cylindrical mold (31) and the second annular cylindrical mold (32) into the tubular blank (2) are coplanar with the central axis of the tubular blank (2) and are located on both sides of the central axis of the tubular blank (2).

6. The method for inner contact spinning of a tubular workpiece with double-ring rollers according to claim 1, characterized in that: The processing angle α1 is 10°-40°; the adjustment angle β1 is ±20°; and the feed angle γ1 is ±5°.

7. The method for rolling a tubular workpiece with double-ring rollers in contact with each other according to claim 2, characterized in that: The processing angle α2 is 10°-40°; the adjustment angle β2 is ±20°; and the feed angle γ2 is ±5°.

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