A die for deforming and forging a forging blank at the crank throw part applied to upset forging a crankshaft

Abstract

The present invention relates to a die for deformation forging and forming a forging blank at the crank throw part of a upset forging crankshaft, which includes an upper moving block, a lower moving block, an upper intermediate die, a lower intermediate die, a lower left die, a lower right die, an upper left die and an upper right die; there are two left and right upper moving blocks, with an arc-shaped groove in the middle, and the upper left moving block and the upper right moving block are combined together, and the arc-shaped grooves of the upper left die and the upper right die form an upper die semi-cavity; there are two left and right lower moving blocks, with an arc-shaped groove in the middle, and the lower left moving block and the lower right moving block are combined together, and the arc-shaped grooves of the lower left die and the lower right die form a lower die semi-cavity; the upper die semi-cavity and the lower die semi-cavity are combined to form a deformation forging and forming forging blank die placement cavity for placing the forging blank. The present invention eliminates the downward frictional force generated by the movement direction of the upset forging die on the surface of the crank throw contour, improves the forging blank forming filling effect, improves the force-bearing condition of the upper and lower intermediate hydraulic cylinders, and improves the service life of the upper and lower intermediate hydraulic cylinders.

Description

Technical Field

[0001] The present invention relates to the field of machining, and particularly to a die for deforming and forging a forging blank at the crankpin part of a upset-forged crankshaft. Background Art

[0002] The crankshaft upset-forging production process technology is a production method in which each crankpin is individually replaced with a die, locally heated, and locally upset-forged and formed. After each batch of forgings is centrally and uniformly replaced with a die, locally heated, and locally upset-forged to produce the same crankpin, the die is then centrally and uniformly replaced, locally heated, and locally upset-forged for the next group of the same crankpins. After multiple batches of die replacement, local heating, and local upset-forging, the forging production of each crankpin and flange of the large crankshaft is completed.

[0003] The prior art crankpin forming intermediate die technology is shown in FIGS. 1-6. The upper intermediate die 14 has features such as a top surface 140 of the inserted balance weight, a contour 141 of the upper die for the crank arm, a surface 143 of the upper die for the connecting rod journal, and a side surface 144 on the connecting rod journal side of the crank arm. The lower intermediate die 15 has features such as a contour 142 of the lower die for the crank arm, a small part of the side surface 144 on the connecting rod journal side of the crank arm, and a surface 145 of the lower die for the connecting rod journal. The upper left die 1 and the upper right die 17 have features of the side surface 147 on the main journal side of about half of the crank arm. The lower left die 11 and the lower right die 21 have features of the side surface 147 on the main journal side of the remaining crank arm and a feature of the dish-shaped surface 146 of the crank arm. During the upset-forging process, the upper and lower intermediate dies move downward. The top surface 140 of the inserted balance weight and the contour 141 of the upper die for the crank arm of the die cavity of the upper intermediate die 14 generate an upset-forging forming force transmitted vertically downward through the cavity. The contour 141 of the upper die for the crank arm also generates a vertical downward cavity surface friction force during the downward movement of the die, affecting the metal flow and filling during crankpin forging. The contour 142 of the lower die for the crank arm of the lower intermediate die 15 bears the Figure 6 normal upset-forging forming reaction force in the direction of the cavity surface, resulting in large force on the lower intermediate die 15, poor rigidity, easy deformation of the die, and serious cracking, causing the die to break, and there has always been a phenomenon of low die life of the lower intermediate die. Summary of the Invention

[0004] To solve the above technical problems, the object of the present invention is to provide a die for deforming and forging a forging blank at the crankpin part of a upset-forged crankshaft; the specific technical solution is as follows:

[0005] A die for deforming and forging a forging blank at the crankpin part of a upset-forged crankshaft, comprising an upper moving block, a lower moving block, an upper intermediate die, a lower intermediate die, a lower left die, a lower right die, an upper left die, and an upper right die;

[0006] The lower left die includes a lower left die a, a lower left die b, and a lower left die c;

[0007] The lower right die includes lower right die a, lower right die b, lower right die c, and lower right die d;

[0008] The upper left die includes upper left die a, upper left die b, and upper left die c;

[0009] The upper right die includes upper right die a, upper right die b, upper right die c, and upper right die d;

[0010] There are two left and right upper moving blocks, with an arc-shaped groove in the middle, and the upper left moving block and the upper right moving block are combined together. The arc-shaped grooves of the upper left die and the upper right die form the upper die semi-cavity;

[0011] There are two left and right lower moving blocks, with an arc-shaped groove in the middle, and the lower left moving block and the lower right moving block are combined together. The arc-shaped grooves of the lower left die and the lower right die form the lower die semi-cavity;

[0012] The upper die semi-cavity and the lower die semi-cavity are combined to form a deformation forging die placement cavity for placing the forging blank.

[0013] For a die used for deformation forging and forming of the crankpin part of a upset forging crankshaft, its preferred solution is that the upper right die and the lower right die are designed according to the spatial distribution direction of the formed crankpin of the forging blank and the contour of the crank arm forging blank;

[0014] The upper left die and the lower left die are designed by determining the positioning groove positions turned according to the volume of metal required for each forming part of the crankpin and flange of the forging blank on the length of the blank.

[0015] For a die used for deformation forging and forming of the crankpin part of a upset forging crankshaft, its preferred solution is that the upper middle die is designed to form a T-shaped upper middle die for the crankpin according to the top surface of the inserted balance block, the upper surface of the connecting rod journal on the upper die, and the side surface features of the connecting rod journal of the crank arm of the forging blank;

[0016] The lower end of the upper middle die is provided with an arc-shaped notch a, and there are protruding parts on both sides;

[0017] The lower middle die is designed according to the side surface of the connecting rod journal of the crank arm and the surface features of the lower die of the connecting rod journal of the forging blank;

[0018] The upper end of the lower middle die is provided with an arc-shaped notch b, and the arc-shaped notch a and the arc-shaped notch b are clamped on the upper and lower surfaces of the connecting rod journal.

[0019] For a die used for deformation forging and forming of the crankpin part of a upset forging crankshaft, its preferred solution is that the upper left die a and the upper right die a are designed according to the top surface of the inserted balance block, the upper die contour of the crank arm, and the side surface features of the main journal of the crank arm;

[0020] The upper left die a is in the shape of an arc-shaped stepped block, with a mold cavity inside, and a concave arc surface is provided on one side of the stepped block. A small part of the mold cavity of the upper left die a is stuck on the top surface of the inserted balancing block, the concave arc surface is stuck on the arc surface of the contour of the upper crank arm die, and the upper surface of the mold cavity of the stepped block is flush with the top surface of the inserted balancing block;

[0021] The upper right die a has the same structure as the upper left die a and is symmetrically arranged on the side of the main journal of the crank arm. A small part of the mold cavity of the upper right die a is stuck on the top surface of the inserted balancing block, the concave arc surface is stuck on the arc surface of the contour of the upper crank arm die, and the upper surface of the mold cavity of the stepped block is flush with the top surface of the inserted balancing block; The protruding part of the upper middle die forms an interlocking lock after being combined with the upper left die a and the upper right die a, and the lower end surface of the protruding part is flush with the upper surface of the mold cavity of the stepped block.

[0022] For a mold used for the deformation forging of the crank throw part of a upset forging crankshaft to form a forging blank, its preferred scheme is that the lower left die a and the lower right die a are designed according to the characteristics of the lower contour die of the crank arm and the dish-shaped surface of the crank arm;

[0023] The lower left die a is in the shape of a "bowl", and the inner arc surface a is stuck on the lower contour die of the crank arm and the dish-shaped surface of the crank arm;

[0024] The lower right die a has the same structure as the lower left die a and is symmetrically arranged on the side of the main journal of the crank arm. The inner arc surface a of the lower right die a is stuck on the lower contour die of the crank arm and the dish-shaped surface of the crank arm.

[0025] For a mold used for the deformation forging of the crank throw part of a upset forging crankshaft to form a forging blank, its preferred scheme is that the upper left die b and the upper left die c and the lower left die b and the lower left die c are set as arc-shaped blocks with notches and are symmetrically arranged on the left side crankshaft of the upper left die a and the lower left die a;

[0026] The upper right die b, the upper right die c, the upper right die d and the lower right die b, the lower right die c, the lower right die d are symmetrically arranged on the right side of the upper right die a and the lower right die a, and arc-shaped blocks protruding or concave are designed according to the characteristics of the contour and mold cavity on the right side.

[0027] For a mold used for the deformation forging of the crank throw part of a upset forging crankshaft to form a forging blank, its preferred scheme is that by adding or removing some fine-tuning pads on the top surface of the upper middle die, it is adjusted whether the lower end surface of the protruding part of the upper middle die is flush with the upper surface of the mold cavity of the stepped block of the upper left die a and the upper right die a.

[0028] Taking the upset forging fourth throw forging blank 5 as an example, the formed crank throw has characteristics such as the top surface of the inserted balancing block, the contour of the upper crank arm die, the contour of the lower crank arm die, the upper surface of the connecting rod journal of the upper die, the lower surface of the connecting rod journal of the lower die, the side surface of the connecting rod journal side of the crank arm, the side surface of the main journal side of the crank arm, and the dish-shaped surface of the crank arm.

[0029] In the present invention, by optimizing the positions of the molds corresponding to each feature of the formed crank, these invariant features are preferably associated with the upper intermediate die a, the lower intermediate die a, the upper left die a, the lower left die a, the upper right die a, and the lower right die a. Specifically: The upper intermediate die of the invented crank only has features such as the top surface of the inserted balance weight, the side surface of the connecting rod neck on the crank arm side, and the upper die surface of the connecting rod neck, and forms a new die feature n at the protruding parts on both sides of the upper middle die of the crank; while the contour feature of the upper die of the crank arm and the upper half of the side surface of the main journal on the crank arm side are designed and manufactured on the upper left die a and the upper right die a, and form a concave die feature r. The lower intermediate die of the invented crank has a small part of the side surface of the connecting rod neck on the crank arm side and the lower die surface feature of the connecting rod neck. The prior art has the contour feature of the lower die of the crank arm, which is optimized and distributed and designed and manufactured on the lower left die a and the lower right die a. At the same time, the lower left die a and the lower right die a still have the dish-shaped surface of the crank arm and the lower half of the side surface of the main journal on the crank arm side.

[0030] The surface area of the upper intermediate die and the lower intermediate die of the present invention in contact with the deformed forged blank (i.e., the horizontal projected area of the die cavity parts of the upper and lower intermediate dies) is greatly reduced, and the reduced part is optimized and distributed on the upper left die a, the lower left die a, the upper right die a, and the lower right die a. In this way, the forging deformation force acting on the upper and lower intermediate dies of the crank during the forging process is reduced as the surface area decreases, which can improve the stress conditions of the upper intermediate hydraulic cylinder and the lower intermediate hydraulic cylinder and extend the service life of the hydraulic cylinder. At the same time, the normal forging deformation force of the die cavity surface of the original crank arm contour of the lower intermediate die is eliminated, and the original bending deformation and cracking and fracture phenomena of the lower intermediate die are significantly improved, and the service life of the lower intermediate die is effectively extended. With the invented technology, under the condition that the upper and lower intermediate hydraulic cylinders are subjected to the same force, forgings with a larger forging contour can be upset-forged.

[0031] During the forging process, the upper left die a, the lower left die a, the upper right die a, and the lower right die only move horizontally towards each other, and there is no die downward friction force acting on the surface of the forged blank generated by the vertical downward movement in the prior art for the contour of the upper die of the crank arm and the contour of the upper die of the crank arm, which is more conducive to the filling of the forged blank during the forging process.

[0032] After the protruding die feature n on both sides of the upper middle die of the crank and the concave die feature r at the recessed parts on the upper left die a and the upper right die a are combined, they form a mutual lock, further improving the symmetry of the crank contour of the formed forged blank. Moreover, at the junction of these two features, it is also the position where the forged blank is most difficult to be filled completely. At the end of the upset forging, the metal of the upset-forged crank will flow into the flash bin with a certain height and width at the junction of these two features to form a flash of the forged blank, and the flash will fill the place where the crank is not easy to be filled completely to achieve the effect of facilitating the complete filling of the forging.

[0033] A die for the deformation forging of the crank throw part of a upset forging crankshaft. Taking the upset forging of the 4th crank throw blank as an example, the press slider and the upsetting upper ejecting tooling connected thereto press downward, driving the downward movement of the connecting rod. The connecting rod rotates around its upper central axis, and the lower central axis of the connecting rod pushes the upper moving block to drive the left and right dies on the upper moving block, namely, upper left die a, upper left die b, upper left die c, upper right die a, upper right die b, upper right die c, upper right die d, to move horizontally linearly towards the center. The lower moving block is in a passive relationship with the upper moving block. Therefore, the lower moving block is passively linked with the upper moving block and drives the lower left die c, lower left die b, lower left die a, lower right die a, lower left die b, lower left die c, lower left die d installed thereon to move towards the center, realizing horizontal upset forging. At the same time, the upper intermediate die a, lower intermediate die a are connected to the upsetting upper ejecting tooling and the lower moving workbench through the upper intermediate hydraulic cylinder and the lower intermediate hydraulic cylinder. During the process of the press slider pressing downward, the upsetting upper ejecting tooling follows the slider downward for pressing. The liquid in the intermediate hydraulic cylinder starts to be discharged under back pressure until the liquid is completely discharged. Before this stage, the left and right dies close the mold to clamp the forging blank and move towards each other to realize upsetting. The upper and lower intermediate dies are filled with liquid and closed through the upper intermediate hydraulic cylinder and the lower intermediate hydraulic cylinder and are in a suspended static state. After the liquid in the upper intermediate hydraulic cylinder is completely discharged, the upper intermediate die a, upper intermediate hydraulic cylinder, upper ejecting tooling are in complete rigid contact and follow the press slider downward together. The upper intermediate die a is pushed downward, and the lower intermediate die a is always connected to the lower intermediate hydraulic cylinder. During the downward movement of the tooling in this stage, the lower intermediate hydraulic cylinder starts to discharge liquid under back pressure, and the lower intermediate die a that is always pressed against always surrounds the deformed forging blank and remains in a closed mold state with the upper intermediate die. In this way, while the upper intermediate die a and the lower intermediate die a drive the forging blank to move downward and bend, the left and right dies continue to move towards each other to realize horizontal upsetting of the forging blank in the local heating area. At the end of the upset forging, when the upper left die a, lower left die a, upper right die a, lower right die a are in complete contact with the upper and lower intermediate dies a of the crank throw, at this time, the liquid discharge of the lower intermediate hydraulic cylinder is just completed. At this time, the upper intermediate hydraulic cylinder, lower intermediate hydraulic cylinder are in rigid contact with the upper intermediate die a, lower intermediate die a, and the upper intermediate hydraulic cylinder, lower intermediate hydraulic cylinder are in rigid contact with the pressure upper ejecting tooling and the moving workbench, thus completing the upset forging and forming of the forging.

[0034] Beneficial effects

[0035] The technical solution of the present invention eliminates the downward friction force generated on the surface of the crank arm contour due to the movement direction of the upset forging die, optimizes the flash of the forging blank that is beneficial to filling and forming, improves the filling effect of the forging blank forming, improves the stress condition of the upper and lower intermediate hydraulic cylinders, and extends the service life of the upper and lower intermediate hydraulic cylinders. Under the same working conditions of the upper and lower intermediate hydraulic cylinders, forgings with larger contours can be produced. Description of the drawings

[0036] Figure 1 It is a schematic diagram of the main components at the end stage of the existing technology upset forging;

[0037] Figure 2 is of the prior art Figure 1 three-dimensional schematic diagram;

[0038] Figure 3 is of the prior art Figure 2 three-dimensional schematic diagram after opening the tooling;

[0039] Figure 4 is of the prior art Figure 3 three-dimensional exploded view of the mold;

[0040] Figure 5 is Figure 4 three-dimensional schematic diagram of the forging blank after forging the fourth bend;

[0041] Figure 6 is Figure 4 view A of the upper and lower intermediate molds;

[0042] Figure 7 is the three-dimensional exploded view of the mold for the deformed forging of the forging blank of the present invention;

[0043] Figure 8 is the combined structure schematic diagram of the upper moving block, the upper intermediate mold and the forging blank;

[0044] Figure 9 is the combined structure schematic diagram of the upper moving block and the upper intermediate mold at the end stage of upsetting after the forging blank is demolded;

[0045] Figure 10 is the combined structure schematic diagram of the lower moving block, the lower intermediate mold and the forging blank;

[0046] Figure 11 is the combined structure schematic diagram of the upper moving block, the lower moving block and the forging blank;

[0047] Figure 12 is the schematic diagram at the beginning stage of upsetting of the upsetting die;

[0048] Figure 13 is the schematic diagram at the end stage of upsetting of the upsetting die;

[0049] Figure 14 is Figure 9 view B;

[0050] Figure 15 is Figure 14 partial enlarged schematic diagram of the area enclosed by circle C;

[0051] Figure 16 is the schematic diagram of the lower moving block structure;

[0052] Figure 17 is the schematic diagram of the structure of the upper left mold a;

[0053] Figure 18 It is a structural schematic diagram of the lower left die a;

[0054] Figure 19 It is a structural schematic diagram of the upper middle die a;

[0055] Figure 20 It is a structural schematic diagram of the lower middle die a.

[0056] Figure 21 It is a structural schematic diagram of the upper right die a;

[0057] Figure 22 It is a structural schematic diagram of the lower right die a.

[0058] In the figure: 1 - upper left die, 2 - upper left die b, 3 - upper left die c, 4 - upper moving block, 5 - forging blank, 6 - lower central axis of connecting rod, 7 - upper central axis of connecting rod, 8 - connecting rod, 9 - lower left die c, 10 - lower left die b, 11 - lower left die, 12 - lower moving block, 13 - upper middle hydraulic cylinder, 14 - upper middle die, 15 - lower middle die, 16 - upper top tooling, 17 - upper right die, 18 - upper right die b, 19 - upper right die c, 20 - upper right die d, 21 - lower right die, 22 - lower right die b, 23 - lower right die c, 24 - lower right die d, 25 - lower middle hydraulic cylinder, 26 - moving workbench, 101 - upper left die a, 104 - upper middle die a, 105 - lower middle die a, 107 - upper right die a, 111 - lower left die a, 121 - lower right die a, 130 - die feature n, 131 - die feature r, 140 - top surface of inlaid balance weight, 141 - upper contour of crank arm die, 142 - lower contour of crank arm die, 143 - upper surface of connecting rod neck of die, 144 - side surface of connecting rod neck of crank arm, 145 - lower surface of connecting rod neck of die, 146 - dish surface of crank arm, 147 - side surface of main journal of crank arm, 150 - arc notch a, 151 - protruding part, 152 - arc notch b, 153 - type groove, 154 - sunken arc surface, 155 - upper surface of step block, 156 - arc surface a. Detailed implementation manners

[0059] The present invention will be further described below in conjunction with the accompanying drawings in the present invention, but it should not be understood that the above-mentioned main scope of the present invention is limited to the following embodiments. Without departing from the above-mentioned idea of the present invention, various substitutions and changes made according to ordinary technical knowledge and customary means in the art should all be included within the protection scope of the present invention.

[0060] As Figure 7-22 shown, a die for deforming and forging a forging blank at the crank throw part of a upset forging crankshaft includes an upper moving block, a lower moving block, an upper middle die, a lower middle die, a lower left die, a lower right die, an upper left die and an upper right die;

[0061] The lower left mold includes lower left mold a111, lower left mold b10, and lower left mold c9;

[0062] The lower right mold includes lower right mold a121, lower right mold b22, lower right mold c23, and lower right mold d24;

[0063] The upper left mold includes upper left mold a101, upper left mold b2, and upper left mold c3;

[0064] The upper right mold includes upper right mold a107, upper right mold b18, upper right mold c19, and upper right mold d20;

[0065] There are two left and right upper moving blocks 4, with an arc-shaped groove in the middle, and the upper left moving block and the upper right moving block are combined together. The arc-shaped grooves of the upper left mold and the upper right mold form the upper mold semi-cavity;

[0066] There are two left and right lower moving blocks 12, with an arc-shaped groove in the middle, and the lower left moving block and the lower right moving block are combined together. The arc-shaped grooves of the lower left mold and the lower right mold form the lower mold semi-cavity;

[0067] The upper mold semi-cavity and the lower mold semi-cavity are combined to form a deformation forging forming blank mold placement cavity for placing the forging blank 5.

[0068] The upper right mold and the lower right mold are designed according to the forming crank spatial distribution direction of the forging blank 5 and the contour of the crank arm forging blank;

[0069] The upper left mold and the lower left mold are designed by determining the positioning groove positions turned on the billet according to the metal volume required for each forming part of the crank and flange of the forging blank 5 at the length position on the blank.

[0070] The upper middle mold a104 is designed according to the characteristics of the balance block top surface 140, the upper mold contour 141 of the crank arm, the upper mold surface 143 of the connecting rod neck, and the side surface 144 of the connecting rod neck of the crank arm of the forging blank 5 to form a T-shaped upper middle mold a104 for the crank;

[0071] The lower end of the upper middle mold a104 is provided with an arc-shaped notch a150, and there are protruding parts 151 on both sides;

[0072] The lower middle mold a105 is designed according to the characteristics of the lower mold contour 142 of the crank arm, the side surface 144 of the connecting rod neck of the crank arm, and the lower mold surface 145 of the connecting rod neck of the forging blank;

[0073] The upper end of the lower middle mold a105 is provided with an arc-shaped notch b152, and the arc-shaped notch a150 and the arc-shaped notch b152 are stuck on the upper and lower surfaces of the connecting rod neck.

[0074] The upper left mold a101 and the upper right mold a107 are designed according to the characteristics of the top surface 140 of the balance block, the contour 141 of the upper mold of the crank arm, and the side surface 147 of the main journal of the crank arm;

[0075] The upper left mold a101 is in the shape of an arc-shaped stepped block, with a mold cavity 153 inside. One side of the stepped block is provided with a concave arc surface 154. The mold cavity 153 of the upper left mold a101 is stuck on the top surface 140 of the balance block, and the concave arc surface 154 is stuck on the inclined surface of the contour 141 of the upper mold of the crank arm. The upper surface 155 of the stepped block is flush with the top surface 140 of the balance block;

[0076] The upper right mold a107 has the same structure as the upper left mold a101 and is symmetrically arranged on the side surface 147 of the main journal of the crank arm. The mold cavity 153 of the upper right mold a107 is stuck on the top surface 140 of the balance block, and the concave arc surface 154 is stuck on the inclined surface of the contour 141 of the upper mold of the crank arm. The upper surface 155 of the stepped block is flush with the top surface 140 of the balance block;

[0077] The protruding part 151 of the upper middle mold a104 forms an interlocking lock with the upper left mold a101 and the upper right mold a107 after the molds are closed, and the lower end surface of the protruding part 151 is flush with the upper surface 155 of the stepped block.

[0078] The lower left mold a111 and the lower right mold a121 are designed according to the characteristics of the lower contour mold 142 of the crank arm and the butterfly surface 146 of the crank arm;

[0079] The lower left mold a111 is in the shape of a "bowl", and the inner arc surface a156 is stuck on the lower contour mold 142 of the crank arm and the butterfly surface 146 of the crank arm;

[0080] The lower right mold a121 has the same structure as the lower left mold a111 and is symmetrically arranged on the side surface 147 of the main journal of the crank arm. The inner arc surface a156 of the lower right mold a121 is stuck on the lower contour mold 142 of the crank arm and the butterfly surface 146 of the crank arm.

[0081] The upper left mold b2 and the upper left mold c3 and the lower left mold b10 and the lower left mold c9 are arranged as arc-shaped blocks with notches and are symmetrically arranged on the left crankshaft of the upper left mold a101 and the lower left mold a111;

[0082] The upper right mold b18, the upper right mold c19, the upper right mold d20 and the lower right mold b22, the lower right mold c23, the lower right mold d24 are symmetrically arranged on the right side of the upper right mold a107 and the lower right mold a121, and are designed as protruding or concave arc-shaped blocks according to the characteristics of the crank arm screw holes and mold cavities on the right side.

[0083] By adding or removing some fine-tuning pads on the top surface of the upper middle mold a104, it is adjusted whether the lower end surface of the protruding part 151 of the upper middle mold a104 is flush with the stepped blocks of the upper left mold a101 and the upper right mold a107.

[0084] Taking the upset forging blank 5 of the fourth crank as an example, the formed crank has features such as the top surface 140 of the inserted balance weight, the upper die contour 141 of the crank arm, the lower die contour 142 of the crank arm, the upper die surface 143 of the connecting rod neck, the lower die surface 144 of the connecting rod neck, most of the side surface 145 on the connecting rod neck side of the crank arm, the side surface 147 of the main journal of the crank arm, and the dish-shaped surface 146 of the crank arm.

[0085] In the present invention, by optimizing the positions of the molds corresponding to each feature of the formed crank, these invariant features are preferably associated with the upper intermediate die a104, the lower intermediate die a105, the upper left die a101, the lower left die a111, the upper right die a117, and the lower right die a121. Specifically: The upper intermediate die a14 of the invented crank only has features such as the top surface 1401 of the inserted balance weight, the side surface 144 on the connecting rod neck side of the crank arm, and the upper die surface 143 of the connecting rod neck, and forms the die features n120 of the protruding parts on both sides of the new upper middle die of the crank; while the upper die contour g1 feature of the crank arm and the upper half of the side surface 147 on the main journal side of the crank arm are designed and manufactured on the upper left die a101 and the upper right die a117, and form the recessed die features r131. The lower intermediate die a105 of the invented crank has a small part of the side surface 144 on the connecting rod neck side of the crank arm and the feature of the lower die surface 145 of the connecting rod neck. The prior art has the feature of the lower die contour 142 of the crank arm, which is optimized and distributed on the lower left die a111 and the lower right die a121. At the same time, the lower left die a111 and the lower right die a121 still have the dish-shaped surface 146 of the crank arm and the lower half of the side surface 147 on the main journal side of the crank arm.

[0086] The surface area of the upper intermediate die and the lower intermediate die of the present invention in contact with the deformed forging blank (i.e., the horizontal projection area of the die cavity parts of the upper and lower intermediate dies) is greatly reduced, and the reduced part is optimized and distributed on the upper left die a101, the lower left die a111, the upper right die a107, and the lower right die a121. In this way, the forging deformation force acting on the upper and lower intermediate dies of the crank during forging is reduced as the surface area decreases, which can improve the stress conditions of the upper intermediate hydraulic cylinder 13 and the lower intermediate hydraulic cylinder, and extend the service life of the hydraulic cylinder. At the same time, the normal forging deformation force of the surface of the die cavity 153 of the original lower die contour 142 of the lower intermediate die a105 is eliminated, and the original bending deformation and cracking and fracture phenomena of the lower intermediate die a105 are significantly improved, and the service life of the lower intermediate die a105 is improved. With the invented technology, under the condition that the upper intermediate hydraulic cylinder 13 and the lower intermediate hydraulic cylinder 25 are subjected to the same force, forgings with a larger forging contour can be upset forged.

[0087] The upper left die a101, the lower left die a111, the upper right die a107, and the lower right die a121 move horizontally towards each other during forging. There is no frictional force of the die moving downward vertically on the surface of the forging blank in the prior art on the contour of the curved arm of the upper die and the contour of the curved arm of the lower die, which is more conducive to the filling of the forging blank during the forging process.

[0088] The protruding die feature n130 on both sides of the upper middle die a104 of the crank forms an interlock with the die feature r131 in the recessed part of the upper left die a101 and the upper right die a107 after die closing, further improving the symmetry of the crank contour of the formed forging blank. Moreover, the junction of these two features is also the position where it is most difficult to fill the forging blank completely. At the end of the upsetting forging, the metal of the upsetting deformed crank will flow to the junction of these two features to form flash on the forging blank, and the flash will fill the unfilled part of the crank to achieve complete filling, resulting in an effect conducive to full filling during forging.

[0089] A die for the deformation forging of the crankpin part of a upset forging crankshaft. Taking the upset forging of the 4th crankpin billet as an example, the press slider and the upsetting upper ejecting tooling 16 connected thereto press downward, driving the downward movement of the connecting rod 8. The connecting rod 8 rotates around its upper central axis 7, and the lower central axis 6 of the connecting rod pushes the upper moving block 4 to drive the upper left die a101, upper left die b2, upper left die c3, upper right die a107, upper right die b18, upper right die c19, upper right die d20 installed on the upper moving block 4 to convert to horizontal linear movement towards the center. The lower moving block 12 is in a passive relationship with the upper moving block 4. Therefore, the lower moving block 12 is passively linked with the upper moving block 4 and drives the lower left die c9, lower left die b10, lower left die a111, lower right die a121, lower right die b22, lower right die c23, lower right die d24 installed thereon to move towards the center, realizing horizontal upset forging. At the same time, the upper intermediate die a104, lower intermediate die a105 are connected to the upsetting upper ejecting tooling 16 and the lower moving workbench 26 through the upper intermediate hydraulic cylinder 13 and the lower intermediate hydraulic cylinder 25. During the process of the press slider pressing downward, the upsetting upper ejecting tooling 16 moves downward following the slider for pressing. The liquid in the intermediate hydraulic cylinder 13 starts to be discharged under back pressure until the liquid is completely discharged. Before this stage, the left and right dies close the mold to clamp the billet and move towards each other to realize upsetting. The upper and lower intermediate dies are filled with liquid and closed through the hydraulic cylinder 13 and the lower intermediate hydraulic cylinder 25 and are in a suspended static state. When the liquid in the intermediate hydraulic cylinder 13 is completely discharged, the upper intermediate die a104, upper intermediate hydraulic cylinder 13, and upper ejecting tooling 16 are in complete rigid contact and follow the press slider downward together, pushing the lower intermediate die a105 downward. The lower intermediate die a105 is always connected to the lower intermediate hydraulic cylinder 25. During the downward movement of the tooling in this stage, the lower intermediate hydraulic cylinder 25 starts to discharge liquid under back pressure, and the lower intermediate die a105 that is always pressed against always surrounds the deformed forging billet 5 and remains in a closed mold state with the upper intermediate die. In this way, while the upper intermediate die a104 and the lower intermediate die a105 drive the forging billet to move downward and bend, the left and right dies continue to move towards each other to realize horizontal upset forging of the forging billet 5 in the local heating area. At the end of the upset forging, when the upper left left die a101, lower left die a111, upper right die a107, lower right die a121 and the crankpin upper intermediate die a104, lower intermediate die a105 are in complete contact, at this time, the discharge of the hydraulic cylinder 25 is just completed. At this time, the upper intermediate hydraulic cylinder 13, lower intermediate hydraulic cylinder 25 are in rigid contact with the upper intermediate die a104, lower intermediate die a105, and the upper intermediate hydraulic cylinder 13, lower intermediate hydraulic cylinder 25 are in rigid contact with the pressure upper ejecting tooling 16 and the moving workbench 26, thus completing the upset forging of the forging.

Claims

1. A mold for deforming and forging a forging blank at the crank throw part of a upset-forged crankshaft, characterized in that: It includes an upper moving block, a lower moving block, an upper intermediate die a, a lower intermediate die a, a lower left die, a lower right die, an upper left die, and an upper right die; The lower left die includes a lower left die a, a lower left die b, and a lower left die c; The lower right die includes a lower right die a, a lower right die b, a lower right die c, and a lower right die d; The upper left die includes an upper left die a, an upper left die b, and an upper left die c; The upper right die includes an upper right die a, an upper right die b, an upper right die c, and an upper right die d; There are two left and right upper moving blocks, with an arc-shaped groove in the middle, and the left upper moving block and the right upper moving block are combined together. The arc-shaped grooves of the upper left die and the upper right die form an upper die semi-cavity; There are two left and right lower moving blocks, with an arc-shaped groove in the middle, and the left lower moving block and the right lower moving block are combined together. The arc-shaped grooves of the lower left die and the lower right die form a lower die semi-cavity; The upper die semi-cavity and the lower die semi-cavity are combined to form a deformation forging die placement cavity for placing the forging blank; The upper right die and the lower right die are designed according to the spatial distribution direction of the forming crank of the forging blank and the contour of the crank arm forging blank; The upper left die and the lower left die are designed by determining the position of the positioning groove turned on the length of the round billet according to the metal volume required for each forming part of the crank and flange of the forging blank; The upper intermediate die a is designed according to the top surface of the inserted balance block of the forging blank, the upper die surface of the connecting rod neck, and the side surface characteristics of the connecting rod neck of the crank arm to form a T-shaped crank upper intermediate die a; The lower end of the upper intermediate die a is provided with an arc-shaped notch a, and there are protruding parts on both sides; The lower intermediate die a is designed according to the side surface of the connecting rod neck of the crank arm of the forging blank and the lower die surface characteristics of the connecting rod neck; The upper end of the lower intermediate die a is provided with an arc-shaped notch b, and the arc-shaped notch a and the arc-shaped notch b are stuck on the upper and lower surfaces of the connecting rod neck; The upper left die a and the upper right die a are designed according to the top surface of the inserted balance block, the upper die contour of the crank arm, and the side surface characteristics of the main journal of the crank arm; The upper left die a is in the shape of an arc-shaped stepped block, with a shaped groove inside. One side of the stepped block is provided with a sunken arc surface. The shaped groove of the upper left die a is stuck on the top surface of the forging blank inserted balance block, the sunken arc surface is stuck on the arc surface of the upper die contour of the crank arm, and the upper surface of the stepped block is flush with the top surface of the inserted balance block; The upper right die a has the same structure as the upper left die a and is symmetrically arranged on the side surface of the main journal of the crank arm. The shaped groove of the upper right die a is stuck on the top surface of the balance block, the sunken arc surface is stuck on the arc surface of the upper die contour of the crank arm, and the upper surface of the stepped block is flush with the top surface of the balance block; The protruding parts of the upper intermediate die a and the upper left die a and the upper right die a form an interlocking lock after the dies are closed, and the lower end surface of the protruding parts is flush with the upper surface of the stepped block; 2. The mold for deforming and forging a forging blank at the crank throw part of an upset-forged crankshaft according to claim 1, characterized in that: The lower left die a and the lower right die a are designed according to the lower contour of the crank arm and the characteristics of the dish-shaped surface of the crank arm; The lower left die a is in the shape of a "bowl", and the arc-shaped surface a provided inside is stuck on the lower contour die of the crank arm and the dish-shaped surface of the crank arm; The lower right die a has the same structure as the lower left die a and is symmetrically arranged on the side surface of the main journal of the crank arm. The arc-shaped surface a provided inside the lower right die a is stuck on the lower contour of the crank arm and the dish-shaped surface of the crank arm; 3. The mold for deforming and forging a forging blank at the crank throw part of an upset-forged crankshaft according to claim 1, characterized in that: The upper left die b and the upper left die c and the lower left die b and the lower left die c are set as arc-shaped blocks with notches and are symmetrically arranged on the left crankshaft of the upper left die a and the lower left die a; The upper right die b, upper right die c, upper right die d and lower right die b, lower right die c, lower right die d are symmetrically arranged on the right side of the upper right die a and lower right die a, and convex or concave arc blocks are designed according to the curved arm profile and groove characteristics on the right side.

4. The mold for deforming and forging a forging blank at the crank throw part of an upset-forged crankshaft according to claim 1, characterized in that: By adding or removing part of the fine-tuning backing plate on the top surface of the upper middle die a, it is adjusted whether the lower end surface of the protruding part of the upper middle die a is flush with the step block groove plane of the upper left die a and upper right die a; for the upset-forged local hot-formed crank forging blank, the operator can visually inspect whether these two places on each curved arm of the hot forging blank are flush, and can intuitively determine the dimensional quality of the upper and lower middle die a moving vertically downward direction of the local hot-formed crank forging blank.

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