Forming method of ring piece with L-shaped outer diameter

Abstract

The invention relates to a forming method of a ring piece with an L-shaped outer diameter. The forming method of the ring piece with the L-shaped outer diameter comprises the following steps that heating is conducted before forging, specifically, a blank is heated to the forging temperature, and heat preservation is conducted for a period of time; blank forging, wherein the blank is sequentially subjected to upsetting, drawing-out and re-upsetting; the height of the blank is H1; a blank punching step: punching the blank by a punch with the diameter of d1 to obtain a ring blank; the ring blank is heated to the ring rolling temperature, and heat preservation is conducted for a period of time; forming the inner diameter of the ring blank into a conical inclined surface by adopting the conical section of the core rod; and a rolling forming step: moving the core rod, and forming the inner diameter of the ring blank into a rectangular section by adopting the cylindrical section of the core rod. The conical section of the core rod is used for pre-grinding and extruding the inner diameter of the ring blank, so that the inner diameter of the ring blank forms a conical inclined surface, and more materials are accumulated at the position with smaller diameter of the inner diameter of the ring blank. And during subsequent rolling forming, the annular groove of the main roller can be rapidly filled with materials accumulated at the inner diameter position, so that mold filling of the extending part of the outer diameter L-shaped ring piece is normal.

Description

Technical Field

[0001] The invention relates to the technical field of special-shaped ring forming, in particular to a method for forming an outer diameter L-shaped ring. Background Art

[0002] Ring forgings are produced through the ring rolling process. The L-shaped rolled ring is processed by using the annular groove opened on the main roller. The inner diameter of the ring blank is pressed by the mandrel to squeeze the outer diameter part of the blank into the annular groove of the main roller to form the protruding part of the outer diameter L-shaped rolled ring.

[0003] However, when this process is used to process outer diameter L-shaped ring forgings, the annular groove is difficult to be completely filled, resulting in a large fillet at the end of the protrusion of the L-shaped ring forging, which seriously affects the dimensional accuracy of the ring forging, and in severe cases may even cause the product to be scrapped. When actually producing L-shaped ring forgings, it is necessary to set a large margin at the protrusion position, and the end of the protrusion must be processed twice to ensure the size requirements. This not only affects the processing efficiency of the outer diameter L-shaped ring forgings, but also causes serious waste of raw materials.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a method for forming an outer diameter L-shaped ring to improve the forming accuracy of the outer diameter L-shaped ring.

[0006] The technical solution of the present invention is as follows:

[0007] The outer diameter L-shaped ring forming method is characterized by comprising the following steps:

[0008] Heating step before forging: the blank is heated to the forging temperature and kept warm for a period of time;

[0009] Billet forging steps: the billet is upset, stretched and upset again in sequence; the billet height is H1;

[0010] Blank punching step: a punch with a diameter of d1 punches the blank to obtain a ring blank;

[0011] Pre-rolling material accumulation steps: the ring blank is heated to the ring rolling temperature and kept warm for a period of time; the inner diameter of the ring blank is formed into a tapered slope using the conical section of the mandrel, and the outer diameter cavity is partially filled;

[0012] Rolling forming steps: moving the mandrel, using the cylindrical section of the mandrel to form the ring blank into an L-shaped cross-section ring with a vertical inner diameter surface.

[0013] A further technical solution is that the size of the ring blank meets the following conditions:

[0014]

[0015] H1=H×K

[0016]

[0017] D1 is the outer diameter of the ring blank; V is the volume of the ring blank; d1 is the inner diameter of the ring blank; H is the height of the ring after forming; K is the coefficient, which depends on the height of the ring after forming; G is the weight of the blank; L is the raw material burning and fire consumption coefficient; W is the weight of the punch during punching; ρ is the density coefficient of the material.

[0018] A further technical solution is that the size of the pre-rolled ring blank meets the following conditions:

[0019]

[0020]

[0021]

[0022]

[0023] d2=P×d1

[0024] S1 is the cross-sectional area of ​​one side of the ring blank; S2 is the cross-sectional area of ​​one side of the ring blank after pre-rolling; D1 is the outer diameter of the ring blank; D2 is the small outer diameter of the ring blank after pre-rolling; d1 is the inner diameter of the ring blank; d2 is the small inner diameter of the ring blank after pre-rolling; H is the height of the ring after forming; H2 is the height of the ring blank after pre-rolling; P is a coefficient, which depends on the inner diameter of the ring after forming.

[0025] A further technical solution is that the pre-forging heating step specifically includes:

[0026] The billet heated to the forging temperature is kept at temperature for:

[0027] T=0.3×D1

[0028] T is the holding time / minute; D1 is the outer diameter of the ring blank (4).

[0029] A further technical solution is that the billet forging step specifically includes:

[0030] Upsetting the blank, the height-to-diameter ratio of the blank after upsetting is 1-1.2;

[0031] The billet is drawn and the height-to-diameter ratio of the drawn billet is 2-2.3;

[0032] The upset blank is in the shape of a pancake, and the upsetting ratio is >2.

[0033] A further technical solution is that the pre-grinding step specifically includes: a main roller contacts the outer diameter of the ring blank, and two tapered rollers contact the upper and lower surfaces of the ring blank respectively; an annular groove is opened on the main roller to form a protruding part of the L-shaped ring.

[0034] A further technical solution is that in the pre-grinding step, while the conical section forms a tapered slope on the inner diameter of the ring blank, the material on the outer diameter of the ring blank is squeezed into and partially fills the annular groove.

[0035] A further technical solution is that, in the rolling forming step, while the cylindrical section forms the inner diameter of the ring blank into a rectangular cross section, the material of the outer diameter portion of the ring blank is squeezed into and completely fills the annular groove.

[0036] A further technical solution is that, in the pre-grinding step, the small-diameter end of the core rod cone section and the annular groove are arranged on the same axial side of the ring blank.

[0037] A further technical solution is that the conical section and the cylindrical section of the core rod are coaxially arranged; when the conical section and the cylindrical section are switched, the core rod is moved along the axis of the core rod.

[0038] The beneficial technical effects of the present invention are as follows:

[0039] (1) The outer diameter L-shaped ring forming method of the present invention is provided with a pre-rolling and accumulating material step. Before executing the rolling forming step, the pre-rolling and accumulating material step is first executed, and the inner diameter of the ring blank is pre-rolled and extruded by the conical section of the mandrel, so that the inner diameter of the ring blank forms a conical inclined surface, that is, more material is accumulated at the position with a smaller diameter of the inner diameter of the ring blank. During the subsequent rolling forming, the material accumulated at the inner diameter position can be quickly filled into the annular groove of the main roller, so that the extended part of the outer diameter L-shaped ring is filled normally, with clear edges and corners, and the manufacturing accuracy of the ring is guaranteed.

[0040] (2) Furthermore, the pre-grinding step heats and insulates the ring blank, reduces the hardness of the ring blank, improves the plasticity of the ring blank, and homogenizes the microstructure of the ring blank, so as to improve the pre-grinding efficiency and the pre-grinding effect.

[0041] (3) Furthermore, the forging steps of the billet include upsetting, drawing and upsetting. The upsetting and drawing actions are repeated. While optimizing the internal structure of the raw material, multiple upsetting also facilitates the adjustment of the billet size and ensures the dimensional accuracy of the billet. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The schematic diagram of the structure of the present invention is shown.

[0043] Figure 2 The schematic diagram of the structure of the present invention in the process of pre-grinding and accumulating materials is shown.

[0044] Figure 3 The schematic diagram of the structure of the present invention during the rolling forming process is shown.

[0045] Markings in the accompanying drawings:

[0046] 1. Main roller; 11. Annular groove; 2. Conical roller; 3. Mandrel; 31. Conical section; 32. Cylindrical section; 4. Ring blank; 41. Extension part. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages of the present invention clearer, the device proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated by the accompanying drawings of this specification are only used to match the content disclosed in the specification, so that people familiar with this technology can understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they do not have technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0048] In the description of the present invention, the orientations or positional relationships indicated by terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, and “circumferential” are defined as orientations or positional relationships based on those shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0049] The outer diameter L-shaped ring forming method comprises the following steps:

[0050] S1. Cutting step, Figure 1 The structural diagram of the present invention is shown in FIG. Figure 1 : First, cut the raw material to obtain a blank of specified length and weight. The blank can be 42CrMo4. 42CrMo4 has high strength and hardenability, and is suitable for manufacturing forgings requiring high strength and large quenched and tempered sections.

[0051] Among them, the size of the ring blank 4 meets the following conditions:

[0052]

[0053] H1=H×K

[0054]

[0055] D1 is the outer diameter of the ring blank 4; V is the volume of the ring blank 4; d1 is the inner diameter of the ring blank 4; H is the height of the ring after forming; G is the weight of the blank; L is the burnout coefficient of the raw material; W is the weight of the punch during punching; ρ is the density coefficient of the material;

[0056] K is a coefficient, which depends on the height of the ring after forming. The K value selection table is as follows:

[0057]

[0058] S2. Pre-forging heating step: The blank is heated to the forging temperature and kept warm for a period of time, specifically:

[0059] Heat the blank to 850℃, and keep it at this temperature for:

[0060] T=0.3×D1

[0061] T is the holding time / minute.

[0062] S3. Billet forging steps: the billet is upset, stretched and upset again in sequence; the billet height is H1;

[0063] The billet forging steps specifically include:

[0064] Upsetting the blank, the height-to-diameter ratio of the blank after upsetting is 1-1.2;

[0065] The billet is drawn and the height-to-diameter ratio of the drawn billet is 2-2.3;

[0066] The upset blank is in the shape of a pancake, and the upsetting ratio is >2.

[0067] The upsetting and stretching actions are repeated to optimize the internal structure of the raw material. Multiple upsetting also makes it easier to adjust the size of the blank and ensure the dimensional accuracy of the blank.

[0068] S4. Blank punching step: a punch with a diameter of d1 punches the blank to obtain a ring blank 4.

[0069] S5. Pre-grinding material accumulation step, Figure 2 The schematic diagram of the structure of the present invention in the process of pre-grinding and accumulating materials is shown in FIG. Figure 2 : The ring blank 4 is heated to the ring rolling temperature and kept warm for a period of time to reduce the hardness of the ring blank 4, improve the plasticity of the ring blank 4, homogenize the microstructure of the ring blank 4, improve the pre-rolling efficiency and improve the pre-rolling effect.

[0070] Then, the main roller 1 contacts the outer diameter of the ring blank 4, and an annular groove 11 is opened on the main roller 1 to form the protruding part of the L-shaped ring; the two tapered rollers 2 contact the upper and lower surfaces of the ring blank 4 respectively; and the mandrel 3 contacts the inner diameter of the ring blank 4. The main roller 1, the tapered roller 2 and the mandrel 3 cooperate to fix the ring blank 4.

[0071] The conical section 31 of the mandrel 3 forms a tapered slope on the inner diameter of the ring blank 4, and the outer diameter cavity is partially filled. At the same time, the material of the outer diameter of the ring blank 4 is squeezed into and partially fills the annular groove 11. Specifically, during the pre-rolling and accumulating step, the small diameter end of the conical section 31 of the mandrel 3 and the annular groove 11 are arranged on the same axial side of the ring blank 4. The inner diameter of the ring blank 4 forms a tapered slope, and the end with a smaller diameter of the inner diameter is close to the annular groove 11, that is, more material is accumulated near the annular groove 11 at the inner diameter, so that the material of the ring blank 4 is filled into the annular groove 11 during subsequent rolling. After the pre-rolling is completed, the annular groove 11 is partially filled with the material of the ring blank 4.

[0072] In order to avoid damage to the ring blank 4 due to the pre-rolling transition, and to avoid too small a pre-rolling range, too little material is accumulated at the inner diameter position, and the accuracy of the subsequent forming steps is affected, the size of the ring blank 4 after pre-rolling meets the following conditions:

[0073]

[0074]

[0075]

[0076]

[0077] d2=P×d1

[0078] S1 is the cross-sectional area of ​​one side of the ring blank 4; S2 is the cross-sectional area of ​​one side of the ring blank 4 after pre-rolling; D1 is the outer diameter of the ring blank 4; D2 is the small outer diameter of the ring blank 4 after pre-rolling; d1 is the inner diameter of the ring blank 4; d2 is the small inner diameter of the ring blank 4 after pre-rolling; H is the height of the ring after forming; H2 is the height of the ring blank 4 after pre-rolling.

[0079] P is a coefficient, which depends on the inner diameter of the ring after forming. The P value selection table is as follows:

[0080]

[0081] The ring blank 4 is subjected to pressure and undergoes plastic deformation during the pre-rolling process. During the plastic deformation process, the change in the material seal of the ring blank 4 is very small, that is, it can be considered that the volume of the ring blank 4 before and after the pre-rolling is equal. That is, the small outer diameter of the ring blank 4 after the pre-rolling can be obtained by the volume of the ring blank 4 before the pre-rolling.

[0082] S6. Rolling forming step, Figure 3 The schematic diagram of the structure of the present invention during the rolling forming process is shown in FIG. Figure 3 :The ring blank 4 is finally rolled into an L-shaped cross-section ring with a vertical inner diameter surface by using a mandrel 3. At the same time, the material of the outer diameter part of the ring blank 4 is squeezed into and completely fills the annular groove 11. The conical section 31 and the cylindrical section 32 of the mandrel 3 are coaxially arranged to facilitate switching of the part contacting the inner diameter. During rolling and forming, when the conical section 31 and the cylindrical section 32 are switched, the mandrel 3 is moved along the axis of the mandrel 3 to allow the cylindrical section 32 to contact and extrude the inner diameter of the ring blank 4. During the extrusion process, the inclined surface of the inner diameter of the ring blank 4 is extruded into a plane, and the material accumulated on the inclined surface is extruded to ensure that the annular groove 11 is completely filled with the material of the ring blank 4, so that the extension part 41 of the outer diameter L-shaped ring is filled normally, with clear edges and corners, and the manufacturing accuracy of the ring is guaranteed. The subsequent secondary processing of the extension part 41 is eliminated, reducing the waste of raw materials.

[0083] It can be seen that the above-mentioned outer diameter L-shaped ring forming method is provided with a pre-rolling and accumulation step. The inner diameter of the ring blank 4 is pre-rolled and extruded by the conical section 31 of the mandrel 3, so that the inner diameter of the ring blank 4 forms a conical inclined surface and partially fills the annular groove 11. During the subsequent rolling forming, the material accumulated at the inner diameter position can be quickly filled into the annular groove 11 of the main roller 1, and the annular groove 11 is filled step by step through two steps to ensure that the extension part 41 of the outer diameter L-shaped ring is filled normally, with clear edges and corners, and the manufacturing accuracy of the ring is guaranteed.

[0084] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for forming an outer diameter L-shaped ring, characterized in that: The steps include: Heating step before forging: the blank is heated to the forging temperature and kept warm for a period of time; Billet forging steps: the billet is upset, stretched and upset again in sequence; the billet height is H1; Blank punching step: a punch with a diameter of d1 punches the blank to obtain a ring blank; Pre-rolling material accumulation steps: the ring blank is heated to the ring rolling temperature and kept warm for a period of time; the inner diameter of the ring blank is formed into a tapered slope using the conical section of the mandrel, and the outer diameter cavity is partially filled; Rolling forming steps: moving the mandrel, using the cylindrical section of the mandrel to form the ring blank into an L-shaped cross-section ring with a vertical inner diameter surface.

2. The outer diameter L-shaped ring forming method according to claim 1, characterized in that: The size of the ring blank meets the following conditions: D1 is the outer diameter of the ring blank; V is the volume of the ring blank; d1 is the inner diameter of the ring blank; H is the height of the ring after forming; K is the coefficient, which depends on the height of the ring after forming; G is the weight of the blank; L is the raw material burning and fire consumption coefficient; W is the weight of the punch during punching; ρ is the density coefficient of the material.

3. The outer diameter L-shaped ring forming method according to claim 1, characterized in that: The size of the pre-rolled ring blank meets the following conditions: d2=P×d1 S1 is the cross-sectional area of ​​one side of the ring blank; S2 is the cross-sectional area of ​​one side of the ring blank after pre-rolling; D1 is the outer diameter of the ring blank; D2 is the small outer diameter of the ring blank after pre-rolling; d1 is the inner diameter of the ring blank; d2 is the small inner diameter of the ring blank after pre-rolling; H is the height of the ring after forming; H2 is the height of the ring blank after pre-rolling; P is a coefficient, which depends on the inner diameter of the ring after forming.

4. The outer diameter L-shaped ring forming method according to claim 1, characterized in that: The pre-forging heating step specifically includes: heating the billet to the forging temperature, and the holding time is: T=0.3×D1 T is the holding time / minute; D1 is the outer diameter of the ring blank.

5. The outer diameter L-shaped ring forming method according to claim 1, characterized in that: The billet forging steps specifically include: upsetting the billet, wherein the height-to-diameter ratio of the upsetting billet is 1-1.2; The billet is drawn and the height-to-diameter ratio of the drawn billet is 2-2.3; The upset blank is in the shape of a pancake, and the upsetting ratio is >2.

6. The method for forming an outer diameter L-shaped ring according to claim 1, characterized in that: The pre-grinding step specifically includes: a main roller contacts the outer diameter of the ring blank, and two tapered rollers contact the upper and lower surfaces of the ring blank respectively; an annular groove is provided on the main roller to form a protruding part of the L-shaped ring piece.

7. The method for forming an outer diameter L-shaped ring according to claim 6, characterized in that: In the pre-grinding step, while the conical section forms the inner diameter of the ring blank into a tapered slope, the material on the outer diameter of the ring blank is squeezed into and partially fills the annular groove.

8. The method for forming an outer diameter L-shaped ring according to claim 6, characterized in that: During the rolling forming step, while the cylindrical section forms the inner diameter of the ring blank into a rectangular cross section, the material of the outer diameter portion of the ring blank is squeezed into and completely fills the annular groove.

9. The method for forming an outer diameter L-shaped ring according to claim 6, characterized in that: During the pre-grinding step, the small-diameter end of the cone section of the core rod and the annular groove are arranged on the same axial side of the ring blank.

10. The method for forming an outer diameter L-shaped ring according to claim 1, characterized in that: The conical section and the cylindrical section of the core rod are coaxially arranged; when the conical section and the cylindrical section are switched, the core rod is moved along the axis of the core rod.

Images