Forging tool and forging method for large-span shaft forgings

Abstract

The invention discloses a forging tool and a forging method for large-span shaft forgings, and belongs to the technical field of forging. The problem of eccentricity of shaft forgings with large cross section span in the drawing process in the prior art is solved. The forging tool for the large-span shaft forgings comprises a limiting tool auxiliary tool, an upper flat anvil and a lower V anvil. The large-span shaft forging comprises a shaft body flange and a shaft neck; the shaft neck is arranged on one end face of the shaft body flange; the shaft body flange and the shaft neck are coaxially arranged; the shaft neck is arranged on the lower V anvil; the end, away from the shaft body flange, of the journal is connected with the manipulator. The upper flat anvil is used for drawing out the journal. The limiting tool assistive device is arranged under the shaft body flange and used for limiting the shaft body flange so as to guarantee the concentricity of the shaft body flange and the shaft neck in the drawing-out process of the large-span shaft type forge piece. The concentricity of the shaft body flange and the shaft neck can be effectively guaranteed, and eccentricity of the shaft body flange is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of forming large-span shaft forgings, and in particular to a forging tool and a forging method for large-span shaft forgings. Background Art

[0002] Large-span shaft forgings are widely used in the field of mechanical manufacturing. It is particularly important to reduce the forging allowance and improve the utilization rate of forgings. Large-span shaft forgings have large cross-sectional differences and are prone to eccentricity when cutting. In actual production, the eccentricity is often reduced by increasing the forging allowance. This method has the characteristics of large machining volume, high cost and long cycle, and is no longer suitable for the current energy-saving and consumption-reducing requirements. Summary of the invention

[0003] In view of the above analysis, the present invention aims to provide an adjustable limiting tooling auxiliary device for large-span shaft forgings, so as to solve the eccentricity problem of shaft forgings with large cross-sectional span in the existing finished product during the lengthening process.

[0004] The purpose of the present invention is mainly achieved through the following technical solutions:

[0005] On the one hand, the present invention provides a forging tool for large-span shaft forgings, the forging tool comprising a limiting tooling auxiliary tool, an upper flat anvil and a lower V anvil;

[0006] Large-span shaft forgings include a shaft flange and a journal; the journal is arranged on the end face of the shaft flange; the shaft flange and the central axis of the journal are arranged coaxially; the journal is placed on the lower V anvil; the end away from the shaft flange is connected to the manipulator, and the upper flat anvil is used to lengthen the journal;

[0007] The limiting tooling auxiliary tool is arranged directly below the shaft flange, and is used to provide limiting effect on the shaft flange, so as to ensure the concentricity between the shaft flange and the shaft neck of the large-span shaft forgings during the drawing process.

[0008] In a possible design, the position limiting tooling auxiliary tool includes a slideway, a slider, and a plurality of pads of different specifications;

[0009] The slider is arranged on the slideway and is slidably connected with the slideway; the cushion block is arranged on the slider; the cushion block is arranged just below the flange of the shaft body and before being extended, and a certain distance is arranged between the two.

[0010] In one possible design, the slide is a wheeled platform vehicle;

[0011] A plurality of pulleys are arranged at the bottom of the wheeled platform vehicle, and the pulleys can slide on the slideway.

[0012] In a possible design, the pads are provided with pin holes, which are arranged along the thickness direction of the pads and penetrate the pads;

[0013] A connecting pin is arranged in the pin hole; the connecting pin is used to fix a plurality of cushion blocks together to form a cushion block combination.

[0014] In one possible design, the number of journals of a long-span shaft forging is two;

[0015] The two journals are respectively arranged on the two end surfaces of the shaft body flange; the two journals are coaxially arranged with the shaft body flange.

[0016] In one possible design, the weight of the long-span shaft forgings is 95t-147t.

[0017] On the other hand, the present invention also provides a forging method for a large-span shaft forging, using the forging tool for the large-span shaft forging; the forging method comprises the following steps:

[0018] Step 1: forging a preform of a large-span shaft forging using a steel ingot, and then returning the preform of the large-span shaft forging to a furnace for heating;

[0019] Step 2: Place the limiting tooling auxiliary tool on the walkway, and then place the preform of the large-span shaft forging that has been returned to the furnace for heating on the forging tooling;

[0020] Step 3, lengthening the journal of the preform of the large-span shaft forging;

[0021] Step 31: First anvil width extension:

[0022] Before the first anvil width drawing, first determine the parking position of the limit fixture and the distance between the bottom surface of the shaft flange and the top surface of the limit fixture, and then use the upper flat anvil to apply force to the shaft neck to draw it out;

[0023] Step 32: Second anvil width extension:

[0024] After the first anvil width is stretched, use the manipulator to move the axle neck by a distance of X1, 1 / 2 anvil width ≤ X1 ≤ 1 anvil width, align the unstretched part of the blank with the upper flat anvil, determine the parking position of the wheeled platform vehicle, and move the limiting tooling to the position directly below the end point of the axle flange after the second anvil width of the blank is stretched;

[0025] Step 4: Repeat the drawing process in step 3 until the finished product is forged, and obtain the shaft flange and shaft neck that meet the size requirements of the forging drawing.

[0026] Furthermore, the above step 1 includes the following sub-steps:

[0027] Step 11, heating the steel ingot to 1240°C-1260°C, and keeping the temperature for 19-26 hours; after keeping the temperature for a certain period of time, taking the steel ingot out of the furnace for forging;

[0028] Step 12, upsetting and stretching the steel ingot;

[0029] Step 13, using the upper flat anvil and the lower V anvil to perform stretching and blanking, after pressing out the step, stretching to the required size to obtain the preform;

[0030] Step 14: Return the preforms of the large-span shaft forgings to the furnace for heating.

[0031] Further, in step 31, the process of lengthening the first anvil width includes:

[0032] The pressing amount of the upper flat anvil is set to 5%-10%. After the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine. Then, the upper flat anvil is used to press the blank down for the second time. After the pressing is completed, it is rotated 30°-45°. The upper flat anvil is pressed down repeatedly. After the upper flat anvil completes the stretching of one surface each time, the operating machine is used to rotate the blank 30°-45° until the size of the stretched part of the blank is equal to the finished product size.

[0033] Further, in step 31, the position limiting tooling auxiliary tool is located directly below the end point of the axle flange after the first anvil width stretching of the blank.

[0034] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0035] (1) The forging tooling of the present invention includes a position limiting tooling auxiliary tool. During the drawing process of large-span shaft forgings, the shaft flange and the shaft neck have a large span, and the two are prone to eccentricity. The present invention uses a position limiting tooling auxiliary tool to limit the shaft flange in real time during the drawing process and correct the deviation in time, thereby ensuring the coaxiality and concentricity of the shaft flange and the shaft neck and avoiding eccentricity.

[0036] (2) The forging tooling of the present invention comprises a slideway, a wheeled platform trolley and a cushion block combination; the wheeled platform trolley is used in conjunction with the slideway to move the wheeled platform trolley at any time to ensure that the trolley can move along with the material, and the cushion block combination can be moved at any time to provide a limit for the axle flange.

[0037] (3) The forging method of the present invention utilizes a limiting tooling auxiliary tool to limit the position of the forging during the drawing process. Every time the blank shaft neck is drawn one anvil width, the blank shaft neck is deformed, the shaft neck becomes thinner, and the shaft neck length increases. During the drawing process of the blank shaft neck, the shaft body flange will bend downward to a certain extent (the shaft body flange is heavy and the bottom has no limit). Therefore, before the shaft neck is drawn to the finished size, the bottom surface of the shaft body flange first contacts the top surface of the pad assembly. At this time, the pad assembly begins to provide limiting for the shaft body flange until the size of the drawn portion of the shaft neck meets the finished size of the shaft neck. Therefore, the present invention utilizes a limiting tooling auxiliary tool to provide limiting for the shaft body flange in a timely manner, and to correct the eccentricity of the shaft body flange in a timely manner, so as to ensure that the concentricity of the shaft body flange and the shaft neck can be guaranteed during the drawing process of each anvil width, thereby ensuring that the final product can meet the concentricity requirements of the shaft body flange and the shaft neck.

[0038] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0040] Figure 1 It is an axonometric view of the cushion block assembly of the present invention;

[0041] Figure 2 This is a schematic diagram of the shaft neck before lengthening;

[0042] Figure 3 Produce the axonometric drawing of the finished product after the shaft neck is stretched;

[0043] Figure 4 This is a schematic diagram of the finished product after the shaft neck is stretched;

[0044] Figure 5 This is the axonometric drawing of the limiting tooling auxiliary equipment.

[0045] Reference numerals:

[0046] 1-preform; 2-lower V anvil; 3-slideway; 4-wheeled platform vehicle; 5-pad assembly; 6-axle body flange; 7-axle neck; 8-pin hole. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0048] The present invention provides a forging tool for large-span shaft forgings, such as Figures 1 to 5 As shown, the forging tool includes a limiting tooling auxiliary tool, an upper flat anvil and a lower V-anvil 2; the large-span shaft forgings include a shaft flange 6 and a shaft neck 7; the shaft neck 7 is arranged on the end face of the shaft flange 6; the shaft flange 6 and the central axis of the shaft neck 7 are coaxially arranged; during forging, the shaft neck 7 is located on the lower V-anvil 2; the end of the shaft neck 7 away from the shaft flange 6 is connected to the manipulator, and the upper flat anvil is used to stretch the shaft neck 7; the limiting tooling auxiliary tool is arranged directly below the shaft flange 6, and the limiting tooling auxiliary tool is used to provide a limit for the shaft flange 6 to ensure the concentricity of the shaft flange 6 and the shaft neck 7 of the large-span shaft forgings during the stretching process.

[0049] Specifically, in the drawing process of large-span shaft forgings, the shaft flange 6 and the shaft neck 7 are prone to eccentricity due to the large span of the two. The present invention adopts a limiting tooling auxiliary tool in the drawing process, which can limit the shaft flange 6 in real time during the drawing process and correct the deviation in time, thereby ensuring the coaxial concentricity of the shaft flange 6 and the shaft neck 7 and avoiding the eccentricity problem.

[0050] Compared with the prior art, the present invention can limit the shaft body flange 6 in real time by setting a limiting tooling auxiliary tool, thereby ensuring the coaxial concentricity of the shaft body flange 6 and the shaft neck 7.

[0051] During the drawing process of large-span shaft forgings, in order to enable the limiting tooling to limit the shaft flange 6, the limiting tooling of the present invention includes a slideway 3, a slider and a plurality of pads of different specifications; the slider is arranged on the slideway 3 and is slidably connected to the slideway 3; the pad is located on the slider and is directly below the shaft flange 6. Before drawing, a certain distance is set between the shaft flange 6 and the top surface of the pad.

[0052] The present invention can timely move the position of the cushion block by setting the slider to slide on the slideway 3, so that the cushion block can timely provide a limit for the shaft flange 6. Compared with extending the length of the limit tooling auxiliary tool, the present invention can reduce the material occupation and reduce the cost by setting the slideway 3 and the slider; in addition, it is convenient to operate the overhead crane, and there is no need to consider the tonnage limit of the large-span shaft forgings.

[0053] In order to reduce friction resistance, the sliding block of the present invention includes a wheeled platform vehicle 4 ; a plurality of pulleys are provided at the bottom of the wheeled platform vehicle 4 , and the pulleys can slide on the slideway 3 .

[0054] Specifically, the wheeled platform vehicle 4 of the present invention is provided with four pulleys at the bottom. The four pulleys cooperate with the slideway 3 to realize the movement of the wheeled platform vehicle 4 at any time, thereby realizing the vehicle moving with the materials. In addition, the platform vehicle adopts a four-wheel type to avoid the occurrence of unbalanced loading, thereby improving the stability of the wheeled platform vehicle 4.

[0055] In order to prevent sliding between the pads when the overhead crane lifts the pad assembly 5, the pads of the present invention are provided with pin holes 8, and the number of pin holes 8 is multiple (for example, 2, 4); the pin holes 8 are arranged along the thickness direction of the pad and penetrate the pad; a connecting pin is provided in the pin hole 8; the connecting pin is used to fix multiple pads together.

[0056] Compared with the prior art, the present invention utilizes a connecting pin to be inserted into the pin hole 8 of the cushion block assembly 5, which can limit the sliding between the cushion blocks and avoid misalignment between the cushion blocks when the cushion block assembly 5 is lifted by the overhead travelling crane.

[0057] In order to meet the existing production requirements of large-span shaft forgings, the pads of the present invention include 12 pads with a total of 9 specifications, namely, one first pad with a height of H=500mm, one second pad with a height of H=300mm, two third pads with a height of H=100mm, one fourth pad with a height of H=50mm; one fifth pad with a height of H=30mm, two sixth pads with a height of H=10mm, one seventh pad with a height of H=5mm, one eighth pad with a height of H=3mm, and two ninth pads with a height of H=1mm.

[0058] The present invention can meet the requirement of limiting the cross-sectional difference within the range of 1110mm through the stacking scheme of the above-mentioned different pads. After stacking, the connecting pin is placed in the preset pin hole 8 to prevent the pads from sliding left and right when the overhead crane lifts the pad combination 5.

[0059] It should be noted that the connecting pins of the present invention include pins of multiple standard lengths, which can meet the requirements of the pad block combination 5 of different heights.

[0060] It should be emphasized that the setting height of the limiting tooling auxiliary device is determined by the cross-sectional difference between the shaft flange 6 and the finished shaft neck 7 of the large-span shaft forging, and the minimum cross-sectional difference between the shaft flange 6 and the shaft neck 7 is the forging allowance value.

[0061] It should be pointed out that in actual production, when the difference between the cross-sectional difference of the shaft flange 6 and the shaft journal 7 is small, the shaft flange 6 and the shaft journal 7 will be forged into a smooth axis. At this time, the forging allowance is used as the critical value. If it is greater than the forging allowance, the shaft flange 6 and the shaft journal 7 are forged separately, and if it is less than the forging allowance, the two are forged into a smooth axis. The forging allowance is related to the maximum cross-sectional size and total length of the rough forging.

[0062] The present invention also provides a forging method for a large-span shaft forging, using the forging tool mentioned above, the forging method comprises the following steps:

[0063] Step 1: forging a preform 1 of a large-span shaft forging using a steel ingot, and then returning the preform 1 of the large-span shaft forging to a furnace for heating;

[0064] Step 11, heating the steel ingot to 1240°C-1260°C, determining the holding time according to the weight of the steel ingot and the maximum cross-sectional size, and taking it out of the furnace for forging after holding it for a certain period of time;

[0065] In the above step 11, after heat preservation, the riser end of the steel ingot is clamped, and the size of the clamp meets the size requirements of the drain pan.

[0066] In the above step 11, after the jaws are pressed, the ingot is returned to the furnace for heating, and the heating temperature is 1240°C-1260°C; the holding time is still determined according to the weight of the ingot and the maximum cross-sectional size of the ingot; for example, when the weight of the ingot is 95T-114T and the cross-sectional size is 2000-2300mm, the holding time is 19-26h; when the weight of the ingot is 115T-131T and the cross-sectional size is 2300-2500mm, the holding time is 20-28h; when the weight of the ingot is 132T-147T and the cross-sectional size is 2500-2700mm, the holding time is 22-30h.

[0067] Step 12, upsetting and stretching the steel ingot;

[0068] In the above step 12, the steel ingot is upset and stretched by the central compaction method of upsetting and stretching; the purpose of upsetting and stretching is to break up the as-cast structure at the core of the steel ingot, and at the same time to compact the metallurgical defects of looseness and shrinkage cavities in the core, and finally to strengthen the deformation of the core of the steel ingot and forge the internal defects of the steel ingot.

[0069] During drawing, the reduction amount is 20%-30% each time; the purpose of controlling the reduction amount within the range of 20%-30% is to avoid excessive reduction amount causing cracks on the forging surface. In addition, when the reduction amount is too high, the press will be overloaded for a long time and will be subjected to greater pressure and wear, and the service life of the equipment will be shortened.

[0070] Step 13, using the upper flat anvil and the lower V anvil 2 to perform stretching and blanking, after pressing out the step, stretching to the required size to obtain the preform 1;

[0071] In the above step 13 , the preform 1 includes an axle body flange 6 and a journal 7 at one end or journals 7 at both ends.

[0072] Step 14, returning the preform 1 of the large-span shaft forging to the furnace for heating;

[0073] In the above step 14, the reheating temperature of the preform 1 of the large-span shaft forgings is 1240°C-1260°C, and the holding time is determined according to the weight of the steel ingot and the maximum cross-sectional size of the steel ingot; for example, when the weight of the steel ingot is 95T-114T and the cross-sectional size is 2000-2300mm, the holding time is 19-26h; when the weight of the steel ingot is 115T-131T and the cross-sectional size is 2300-2500mm, the holding time is 20-28h; when the weight of the steel ingot is 132T-147T and the cross-sectional size is 2500-2700mm, the holding time is 22-30h.

[0074] Step 2: Place the limiting tooling auxiliary tool on the walkway, and then place the preform 1 of the large-span shaft forging that has been returned to the furnace for heating on the forging tooling;

[0075] Step 21, first lay the slide 3 flat on the walkway, and the slide 3 is arranged on one side of the upper flat anvil and the lower V anvil 2;

[0076] Step 22: placing the wheeled platform vehicle 4 on the slideway 3 and conducting a test run inspection on the wheeled platform vehicle 4;

[0077] Step 23, determine the height of the limiting tooling auxiliary tool;

[0078] In the above step 23, the height of the limiting tooling auxiliary tool is first determined, and then the height of the required pad block combination 5 is calculated based on the height of the limiting tooling auxiliary tool; after determining the required pads, the pads are stacked together and connected with connecting pins inserted into the preset pin holes 8 on the pads to form a pad block combination 5, and the combined pads are placed on the wheeled platform vehicle 4 using an overhead crane.

[0079] In the above step 23, in order to ensure that the position limiting tooling auxiliary tool can be placed under the shaft flange 6, the process of determining the height of the position limiting tooling auxiliary tool is as follows:

[0080] Before the finished product:

[0081] H 下砧 +R 下料轴颈7 =R 成品轴身法兰6 +H 限位工装 +D; (1)

[0082] After the finished product:

[0083] H 下砧 +R 成品轴颈7 =R 成品轴身法兰6 +H 限位工装 ; (2)

[0084] From the above formulas (1) and (2), we can know that:

[0085] D=R 下料轴颈7 -R 成品轴颈7 ; (3)

[0086] From the above formula (2), we can know that:

[0087] H 限位工装 =H 下砧 -R 成品轴身法兰6 +R 成品轴颈7 ; (4)

[0088] Wherein, D is the distance between the shaft flange 6 and the top surface of the limiting fixture; H 下砧 is the height of the lower V anvil 2, R 下料轴颈7 R is the radius size of journal 7 after blanking. 成品轴身法兰6 H is the radius size of the finished shaft flange 6. 限位工装 is the height of the limiting tooling auxiliary tool, R 成品轴颈7 It is the radius size of the finished rear journal 7.

[0089] Step 24, test run the wheeled platform vehicle 4 again to ensure that the platform vehicle can slide smoothly on the slideway 3; then place the journal 7 of the large-span shaft forging on the lower V-anvil 2, the shaft body flange 6 of the large-span shaft forging is located above the slideway 3, the shaft body flange 6 is at a certain distance from the upper end surface of the limiting tooling auxiliary tool, and the manipulator clamps the end of the journal 7 away from the shaft body flange 6;

[0090] Step 3, drawing the shaft neck 7 of the preform 1 of the large-span shaft forging;

[0091] Step 31: First anvil width extension:

[0092] Before the first anvil width stretching, first determine the parking position of the limiting tooling auxiliary tool, and then use the upper flat anvil to apply force to the shaft neck 7 for stretching; the specific process of the first anvil width stretching is: the pressing amount of the upper flat anvil is 5%-10%, and after the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine, and then the upper flat anvil is used to press the blank down for the second time, and after the pressing is completed, it is rotated 30°-45°, and the upper flat anvil is repeatedly pressed down. After the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine until the size of the stretched part of the blank is equal to the finished product size.

[0093] It should be noted that during the first anvil width drawing process, the blank shaft neck 7 is drawn, that is, the blank shaft neck 7 is deformed axially, its length increases, and the shaft neck 7 becomes thinner; during the process of the blank shaft neck 7 being drawn, the shaft body flange 6 will bend downward to a certain extent (the shaft body flange 6 is heavy and has no limit on the bottom). Therefore, before the shaft neck 7 is drawn to the finished size, the bottom surface of the shaft body flange 6 first contacts the top surface of the cushion block assembly 5. At this time, the cushion block assembly 5 begins to provide limiting for the shaft body flange 6 until the size of the drawn part of the shaft neck 7 meets the finished size of the shaft neck 7.

[0094] Step 32: Second anvil width extension:

[0095] In the above step 32, after the first anvil width is stretched, the operating machine is used to move the journal 7X1 distance, 1 / 2 anvil width ≤ X1 ≤ 1 anvil width, and the unstretched part of the blank is aligned with the upper flat anvil, and the parking position of the wheeled platform vehicle 4 is determined, so that the limiting tooling auxiliary tool is moved to the bottom of the end position of the axle body flange 6 after the second circle of the blank is stretched.

[0096] In the above step 32, after the first anvil width is stretched and before the second anvil width is stretched, the parking position of the wheeled platform vehicle 4 is determined: the position X2 of the limit tooling auxiliary tool is moved, X2=X1, and the moving direction of the limit tooling auxiliary tool is the same as the moving direction of the journal 7, ensuring that the limit tooling auxiliary tool moves to the end position of the axle body flange 6 after the second circle of the blank is stretched.

[0097] In the above step 32, the process of the second anvil width stretching includes: using the upper flat anvil to press down, the pressing amount of the upper flat anvil is 5%-10%, after the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine, and then, the upper flat anvil is used to press the blank down for the second time, and then rotated 30°-45° after pressing, and the upper flat anvil is repeatedly pressed down. After the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine until the size of the stretched part of the blank is equal to the finished product size.

[0098] During the second anvil width drawing process, the blank shaft neck 7 is drawn, that is, the blank shaft neck 7 is deformed axially, its length increases, and the shaft neck 7 becomes thinner; during the process of the blank shaft neck 7 being drawn, the shaft body flange 6 will bend downward to a certain extent (the shaft body flange 6 is heavy and has no limit at the bottom). Therefore, before the shaft neck 7 is drawn to the finished size, the bottom surface of the shaft body flange 6 first contacts the top surface of the cushion block assembly 5. At this time, the cushion block assembly 5 begins to provide limiting for the shaft body flange 6 until the size of the drawn part of the shaft neck 7 meets the finished size of the shaft neck 7.

[0099] Step 4: Repeat the drawing process in step 3 until the finished product is forged, and obtain the shaft flange 6 and the shaft neck 7 that meet the size requirements of the forging drawing.

[0100] Compared with the prior art, during the forging drawing process, the limiting tooling auxiliary tool can provide timely limitation for the shaft body flange 6 every time the blank shaft neck 7 is drawn one circle, and promptly correct the eccentricity of the shaft body flange 6, thereby ensuring the concentricity of the shaft body flange 6 and the shaft neck 7 during the drawing process of each anvil width, thereby ensuring that the final product can meet the concentricity requirements of the shaft body flange 6 and the shaft neck 7.

[0101] It should be noted that the position limiting tooling auxiliary tool of the present invention can meet the requirements of multiple sizes of forgings, and the length and width specifications of the pad can be matched and selected according to the width size of the shaft flange 6 of the forging.

[0102] Example 1

[0103] The ingot type of a certain shaft forging is 104T, the height of the lower V anvil and the bottom pad is 1750mm in total, the dimensions of the preform 1 are shaft body flange 6 diameter φ3000mm, length 600mm, shaft neck 7 diameter φ1670mm, length 1750mm; the dimensions of the finished forging are shaft body flange 6 φ3000mm, length 600mm, shaft neck 7 diameter φ1250mm, length 3000mm.

[0104] The specific forging process is as follows:

[0105] Step 1: forging a preform 1 of a large-span shaft forging using a steel ingot, and then returning the preform 1 of the large-span shaft forging to a furnace for heating;

[0106] Step 11, heat the steel ingot to 1250°C, determine the insulation time according to the weight of the steel ingot and the maximum cross-sectional size, and take it out of the furnace for forging after a certain insulation time; after insulation, press the jaws on the riser end of the steel ingot, and the jaw size meets the leakage plate size requirements.

[0107] In the above step 11, after the jaws are pressed, the steel ingot is returned to the furnace for heating at a temperature of 1250° C. and a heat preservation time of 24 hours.

[0108] Step 12, upsetting and stretching the steel ingot;

[0109] When KD is stretched, the amount of pressure reduction is 25% each time;

[0110] Step 13, use the upper flat anvil and the lower V anvil 2 to stretch and cut the material, the anvil width is 850mm, and after pressing out the step, stretch it to the required size to obtain the preform 1, which includes the shaft body flange 6 and the shaft neck 7 at one end.

[0111] Step 14: Return the preform 1 of the large-span shaft forging to the furnace for heating at a temperature of 1250° C. The holding time is determined according to the weight of the steel ingot and the maximum cross-sectional size of the steel ingot.

[0112] Step 2: Place the limiting tooling auxiliary tool on the walkway, and then place the preform 1 of the large-span shaft forging that has been returned to the furnace for heating on the forging tooling;

[0113] Step 21, first lay the slide 3 flat on the walkway, and the slide 3 is set on one side of the upper flat anvil and the lower V anvil 2; the specification of the slide 3 is 300×2500mm;

[0114] Step 22: Place the wheeled platform vehicle 4 on the slideway 3, the platform size is 300×600 mm, and conduct a test run inspection on the wheeled platform vehicle 4;

[0115] Step 23, determine the height of the limiting tooling auxiliary tool;

[0116] In the above step 23, the height of the position limiting tooling auxiliary tool is first determined, and then the height of the required cushion block assembly 5 is calculated according to the height of the position limiting tooling auxiliary tool.

[0117] Determine the height of the position limiting fixture according to the cross-sectional difference of the finished product size: 1750-(3000-1250) / 2=875mm. In order to ensure that the flange 6 of the axle body contacts the top surface of the position limiting fixture after the extension, it is necessary to design a position limiting fixture with a height of 875mm, and select six pads with heights of 500mm, 300mm, 50mm, 10mm, 10mm and 5mm. The length and width of the pads are 300mm×600mm. After determining the required pads, stack the pads together and insert the connecting pins into the preset pin holes 8 on the pads to form a pad combination 5, and use an overhead crane to place the combined pads on the wheeled platform vehicle 4.

[0118] Step 24, test run the wheeled platform vehicle 4 again to ensure that the platform vehicle can slide smoothly on the slideway 3; then place the journal 7 of the large-span shaft forging on the lower V-anvil 2, the shaft body flange 6 of the large-span shaft forging is located above the slideway 3, the shaft body flange 6 is at a certain distance from the upper end surface of the limiting tooling auxiliary tool, and the manipulator clamps the end of the journal 7 away from the shaft body flange 6;

[0119] Step 3, drawing the shaft neck 7 of the preform 1 of the large-span shaft forging;

[0120] Step 31: First anvil width extension:

[0121] Before the first anvil width drawing, first determine the parking position of the limiting tooling auxiliary tool, and then use the upper flat anvil to apply force to the shaft neck 7 for drawing; the specific process of the first anvil width drawing is: the pressing amount of the upper flat anvil is 8%, and after the upper flat anvil completes the drawing of one surface, the blank is rotated 45° by the operating machine, and then the upper flat anvil is used to press the blank down for the second time. After the pressing is completed, it is rotated 45°, and the upper flat anvil is pressed down repeatedly. After the upper flat anvil completes the drawing of one surface, the blank is rotated 45° by the operating machine until the size of the drawn part of the blank is equal to the finished product size.

[0122] It should be noted that during the first anvil width drawing process, the blank shaft neck 7 is drawn, that is, the blank shaft neck 7 is deformed axially, its length increases, and the shaft neck 7 becomes thinner; during the process of the blank shaft neck 7 being drawn, the shaft body flange 6 will bend downward to a certain extent (the shaft body flange 6 is heavy and has no limit on the bottom). Therefore, before the shaft neck 7 is drawn to the finished size, the bottom surface of the shaft body flange 6 first contacts the top surface of the cushion block assembly 5. At this time, the cushion block assembly 5 begins to provide limiting for the shaft body flange 6 until the size of the drawn part of the shaft neck 7 meets the finished size of the shaft neck 7.

[0123] Step 32: Second anvil width extension:

[0124] In the above step 32, after the first anvil width is stretched, the operating machine is used to move the journal 7X1 distance, 1 / 2 anvil width ≤ X1 ≤ 1 anvil width, and the unstretched part of the blank is aligned with the upper flat anvil, and the parking position of the wheeled platform vehicle 4 is determined, so that the limiting tooling auxiliary tool is moved to the bottom of the end position of the axle body flange 6 after the second circle of the blank is stretched.

[0125] In the above step 32, after the first anvil width is stretched and before the second anvil width is stretched, the parking position of the wheeled platform vehicle 4 is determined: the position X2 of the limit tooling auxiliary tool is moved, X2=X1, and the moving direction of the limit tooling auxiliary tool is the same as the moving direction of the journal 7, ensuring that the limit tooling auxiliary tool moves to the end position of the axle body flange 6 after the second circle of the blank is stretched.

[0126] In the above step 32, the process of the second anvil width stretching includes: using the upper flat anvil to press down, the pressing amount of the upper flat anvil is 8%, after the upper flat anvil completes the stretching of one surface, the blank is rotated 45° by the operating machine, and then, the upper flat anvil is used to press the blank down for the second time, and then rotated 45° after the pressing, the upper flat anvil repeats the pressing down, and the upper flat anvil repeats the pressing down. After the upper flat anvil completes the stretching of one surface, the blank is rotated 45° by the operating machine until the size of the stretched part of the blank is equal to the finished product size.

[0127] During the second anvil width drawing process, the blank shaft neck 7 is drawn, that is, the blank shaft neck 7 is deformed axially, its length increases, and the shaft neck 7 becomes thinner; during the process of the blank shaft neck 7 being drawn, the shaft body flange 6 will bend downward to a certain extent (the shaft body flange 6 is heavy and has no limit at the bottom). Therefore, before the shaft neck 7 is drawn to the finished size, the bottom surface of the shaft body flange 6 first contacts the top surface of the cushion block assembly 5. At this time, the cushion block assembly 5 begins to provide limiting for the shaft body flange 6 until the size of the drawn part of the shaft neck 7 meets the finished size of the shaft neck 7.

[0128] Step 4: Repeat the drawing process in step 3 until the finished product is forged, and obtain the shaft flange 6 and the shaft neck 7 that meet the size requirements of the forging drawing, and the concentricity of the two is good.

[0129] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A forging tool for large-span shaft forgings, characterized in that: Including limiting tooling, upper flat anvil and lower V anvil; The large-span shaft forging comprises a shaft body flange and a shaft neck; the shaft neck is arranged on the end surface of the shaft body flange; the shaft body flange and the central axis of the shaft neck are arranged coaxially; the shaft neck is placed on the lower V-anvil; one end away from the shaft body flange is connected to the manipulator, and the upper flat anvil is used to lengthen the shaft neck; The limiting tooling auxiliary tool is arranged directly below the shaft flange, and is used to provide a limiting effect on the shaft flange to ensure the concentricity of the shaft flange and the shaft neck of the large-span shaft forging during the drawing process.

2. The forging tool for large-span shaft forgings according to claim 1, characterized in that: The position limiting tooling auxiliary tool comprises a slideway, a slider and a plurality of cushion blocks of different specifications; The slider is arranged on the slideway and is slidably connected with the slideway; the cushion block is arranged on the slider; the cushion block is arranged just below the shaft body flange and before being extended, and a certain distance is arranged between the two.

3. The forging tool for large-span shaft forgings according to claim 1, characterized in that: The sliding block is a wheeled platform vehicle; A plurality of pulleys are arranged at the bottom of the wheeled platform vehicle, and the pulleys can slide on the slideway.

4. The forging tool for large-span shaft forgings according to claim 2, characterized in that: The cushion blocks are each provided with a pin hole, which is arranged along the thickness direction of the cushion block and penetrates the cushion block; A connecting pin is arranged in the pin hole; the connecting pin is used to fix a plurality of the cushion blocks together to form a cushion block assembly.

5. The forging tool for large-span shaft forgings according to claim 1, characterized in that: The number of journals of the large-span shaft forging is two; The two journals are respectively arranged on the two end surfaces of the shaft body flange; and both journals are coaxially arranged with the shaft body flange.

6. The forging tool for large-span shaft forgings according to claim 1, characterized in that: The weight of the large-span shaft forgings is 95t-147t.

7. A forging method for a large-span shaft forging, characterized in that: A forging tool for a large-span shaft forging according to any one of claims 1 to 6 is used; the forging method comprises the following steps: Step 1: forging a preform of a large-span shaft forging using a steel ingot, and then returning the preform of the large-span shaft forging to a furnace for heating; Step 2: Place the limiting tooling auxiliary tool on the walkway, and then place the preform of the large-span shaft forging that has been returned to the furnace for heating on the forging tooling; Step 3, lengthening the journal of the preform of the large-span shaft forging; Step 31: First anvil width extension: Before the first anvil width drawing, first determine the parking position of the limit fixture and the distance between the bottom surface of the shaft flange and the top surface of the limit fixture, and then use the upper flat anvil to apply force to the shaft neck to draw it out; Step 32: Second anvil width extension: After the first anvil width is stretched, use the manipulator to move the axle neck by a distance of X1, 1 / 2 anvil width ≤ X1 ≤ 1 anvil width, align the unstretched part of the blank with the upper flat anvil, determine the parking position of the wheeled platform vehicle, and move the limiting tooling to the position directly below the end point of the axle flange after the second anvil width of the blank is stretched; Step 4: Repeat the drawing process in step 3 until the finished product is forged, and obtain the shaft flange and shaft neck that meet the size requirements of the forging drawing.

8. The forging method of a large-span shaft forging according to claim 7, characterized in that: The step 1 includes the following sub-steps: Step 11, heating the steel ingot to 1240°C-1260°C, and keeping the temperature for 19-26 hours; after keeping the temperature for a certain period of time, taking the steel ingot out of the furnace for forging; Step 12, upsetting and stretching the steel ingot; Step 13, using the upper flat anvil and the lower V anvil to perform stretching and blanking, after pressing out the step, stretching to the required size to obtain the preform; Step 14: Return the preforms of the large-span shaft forgings to the furnace for heating.

9. The forging method of a large-span shaft forging according to claim 7, characterized in that: In step 31, the process of lengthening the first anvil width includes: The pressing amount of the upper flat anvil is set to 5%-10%. After the upper flat anvil completes the stretching of one surface, the blank is rotated 30°-45° by the operating machine. Then, the upper flat anvil is used to press the blank down for the second time. After the pressing is completed, it is rotated 30°-45°. The upper flat anvil is pressed down repeatedly. After the upper flat anvil completes the stretching of one surface each time, the operating machine is used to rotate the blank 30°-45° until the size of the stretched part of the blank is equal to the finished product size.

10. The forging method of a large-span shaft forging according to claim 9, characterized in that: In step 31, the position limiting tooling auxiliary tool is located directly below the end point of the axle flange after the first anvil width stretching of the blank.

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