Full-tooth-height super-modulus straight gear forge piece and forming device and forming method of full-tooth-height super-modulus straight gear forge piece

Abstract

A full-tooth-height super-large-modulus straight gear forge piece comprises a half-tooth-height step and full-tooth-height steps, and the thickness of the half-tooth-height step is not smaller than the height of a transition arc between every two adjacent full-tooth-height steps. The difference value between the tooth profile contour line of the full-tooth-height super-large-modulus gear forge piece of the full-tooth-height step and the tooth profile contour line of the machined super-large-modulus gear part is uniform, and the tooth profile metal streamlines of the full-tooth-height step are continuously distributed along the tooth profile contour; an upper tooth-shaped punch of the forming device is connected with an upper sliding block of a pressing machine through a switching mechanism, the upper tooth-shaped punch is used for extruding a metal blank in a lower die assembly, and in the extrusion process, forging preparation is achieved through left-right movement of a left die assembly and a right die assembly which are symmetrically arranged. According to the forged piece manufactured through the method, after machining, it can be guaranteed that a metal flow line is distributed along the profile of a part, the metal flow line is basically free of cutting and outcrop phenomena, the strength of the gear is well improved, and the requirements for high-load large-modulus gears in the fields of engineering machinery, ocean equipment and aerospace equipment can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of gear manufacturing, and in particular to a full-tooth-height ultra-large-modulus gear forging and a forming device and a forming method thereof. Background Art

[0002] Gears are important parts in mechanical devices and one of the basic core parts in transmission machinery. Their main function is to transmit power and motion and change the size and direction of speed and torque. With the development of machine tool technology, the precision of gear shaping, gear hobbing and gear grinding equipment is getting higher and higher, and gear processing technology is developing rapidly. For gears without special use requirements, the gears are directly processed from billet metal and can be used after heat treatment and finishing. For gears with special working conditions or extreme load requirements, they need to be forged to form tooth metal streamlines to further improve the mechanical properties of the tooth shape. For small-module gears with low tooth shape (m≤4.5), cold forging or hot forging methods can be used for direct extrusion. The billet can fill the mold cavity after a short radial flow, and the mold life and friction can meet the forming requirements. Large-module gears with high tooth shape (m≥5) are generally large in size. If the hot forging method is used to process the tooth shape, a large volume of blank metal needs to flow over a long distance to fill the full-tooth-height mold cavity. Since the high-temperature blank is in contact with the mold for a long time, the mechanical strength of the mold decreases rapidly due to the temperature rise. At the same time, a large amount of metal flows rapidly at the root of the mold tooth. The lubricant at the root of the tooth also disappears rapidly due to a large amount of friction, resulting in increased friction and difficulty in metal flow. Ultimately, the root of the mold tooth quickly deforms and fails, and the forming of the full-tooth-height ultra-large-module spur gear forgings cannot be achieved. There is a plan to design the forging part as a half-tooth deep forging, such as Figure 2 As shown in the figure, the half-tooth deep forging reduces the metal flow distance and guarantees the die life, but the streamline near the tooth root is cut off after machining, and the goal of improving gear performance cannot be achieved. There is an increasing demand for high-load and ultra-large modulus gears (m≥10) in the fields of engineering machinery, marine equipment, and aerospace equipment, and it is urgent to develop a method for manufacturing ultra-large modulus gears that meets the requirements. Summary of the invention

[0003] In order to overcome the above shortcomings, the present invention provides a full tooth height ultra-large modulus gear forging and its forming device and forming method, so as to realize the batch forming of full tooth height ultra-large modulus spur gears, and the metal streamlines of the formed gears are distributed along the full tooth height tooth profile contour line, so as to improve the gear load-bearing capacity.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: A full-tooth-height super-large-module spur gear forging comprises a half-tooth-height step and a full-tooth-height step, wherein the thickness of the half-tooth-height step is not less than the height of the transition arc between two adjacent full-tooth-height steps, the tooth profile contour line of the full-tooth-height super-large-module gear forging of the full-tooth-height step is uniformly different from the tooth profile contour line of the super-large-module gear part after machining, and the tooth profile metal streamlines of the full-tooth-height step are continuously distributed along the tooth profile contour.

[0005] A forming device for a full-tooth-height ultra-large-module spur gear forging comprises an upper die assembly, a lower die assembly, a left die assembly and a right die assembly. The upper die assembly is an upper tooth-shaped punch, which is connected to an upper slide block of a press through a transfer mechanism. The upper tooth-shaped punch is used to extrude a metal blank in the lower die assembly. During the extrusion process, the preparation of the forging is achieved by the left-right movement of the symmetrically arranged left die assembly and the right die assembly.

[0006] Further optimization, the lower die assembly includes a die base, a die cover plate, an upper toothed die, a lower toothed die, a stop pin, a lower toothed punch and a square push rod, the lower toothed die and the upper toothed die are sequentially installed in the circular stepped hole at the upper end of the die base from bottom to top, the stop pin is inserted into the outer circumference of the lower toothed die and the upper toothed die to form a semicircular groove, the semicircular groove and the semicircular groove in the stepped hole of the die base constitute a circular hole, the lower toothed punch is installed in the die cavity of the lower toothed die, the bottom of the lower toothed punch is connected to the square push rod, the square push rod is inserted into the square hole on the lower end face of the die base, the die cover plate is installed on the upper end of the upper toothed die, and the die cover plate is consolidated with the upper end face of the die base to fix the upper toothed die.

[0007] Further optimization is that the upper toothed die corresponds to the central axis and the semicircular groove of the lower toothed die, the teeth of the upper toothed die and the lower toothed die correspond to each other, the square flange at the head of the square push rod is connected to the square positioning groove of the lower toothed punch, the lower toothed punch passes through the lower toothed die through the square positioning groove, and the lower end of the square push rod is inserted into the square guide rod hole on the lower end face of the die base.

[0008] Further optimization, the left mold assembly includes a left lower pull plate, a left lower connecting plate, a left lower oil cylinder, a left upper connecting plate, a left upper oil cylinder and a left upper pull plate, the left lower pull plate and the left upper pull plate are inserted into the rectangular hole at the left end of the mold base, a rectangular groove is set in the middle of the right side of the left upper pull plate and the left lower pull plate, the left side of the left upper pull plate is connected to the upper left connecting plate, the upper left connecting plate is connected to the left upper oil cylinder head at the front and rear ends of the left upper pull plate, and the two left upper oil hydraulic cylinders are fixedly installed in the left side square groove of the mold base; a rectangular groove is set in the middle of the right side of the left lower pull plate, the left side of the left lower pull plate is connected to the left lower connecting plate, the lower left connecting plate is connected to the left lower oil cylinder head at the front and rear ends of the left lower pull plate, and the two left lower oil hydraulic cylinders are fixedly installed in the left side square groove of the mold base.

[0009] Further optimization, the right mold assembly includes a right lower pull plate, a right lower connecting plate, a right lower cylinder, a right upper connecting plate, a right upper cylinder and a right upper pull plate, the right upper pull plate is inserted into the rectangular groove at the right end of the mold base, a rectangular groove is set in the middle of the left side of the right upper pull plate, the right side of the right upper pull plate is connected to the right upper connecting plate, the upper left connecting plate is connected to the right upper cylinder head at the front and rear ends, and the two right upper hydraulic cylinders are installed and consolidated in the right side square groove of the mold base; the right lower pull plate is inserted into the rectangular groove at the right end of the mold base, a rectangular groove is set in the middle of the left side of the right lower pull plate, the right side of the right lower pull plate is connected to the right lower connecting plate, the lower right connecting plate is connected to the right lower cylinder head at the front and rear ends, and the two right lower hydraulic cylinders are installed and consolidated in the right side direction hole of the mold base.

[0010] Further optimization is that the contour line of the metal blank is smaller than the tooth top circle of the tooth contour line of the upper toothed die cavity of the upper toothed die by △t1, where △t1 is the expansion amount of the blank after heating plus 1mm; the contour line of the lower toothed die cavity of the lower toothed die is larger than the contour line of the upper toothed die cavity by △t2, where △t2 is the expansion amount of the blank after it is ejected from the upper toothed die plus 1mm.

[0011] Further optimization is performed, the width of the left upper pull plate and the right upper pull plate is greater than the width of the left lower pull plate and the right lower pull plate, and the thickness of the left upper pull plate and the right upper pull plate is the same as the full tooth height step of the gear forging.

[0012] A forming method for a full-tooth-height ultra-large-module spur gear forging, the specific steps are as follows: S1. Put the metal blank heated to the hot forging temperature into the die cavity of the lubricated upper toothed die. The upper toothed punch moves downward under the action of the press to extrude the metal blank. When the metal blank fills the die cavity, the upper toothed punch stops moving. S2, the upper left cylinder and the upper right cylinder are used to control the upper left connecting plate and the upper right connecting plate to move to the left and right sides respectively, and drive the upper left pull plate and the upper right pull plate to move to the left and right sides. When the distance between the upper left pull plate and the upper right pull plate is greater than the diameter of the tooth top circle of the upper toothed punch, the movement stops, and then the lower toothed punch drives the direction push rod to drop downward, and the lower toothed punch contacts the upper end surfaces of the upper left pull plate and the upper right pull plate; S3, the upper toothed punch continues to extrude the metal blank, and the metal blank enters the cavity of the lower toothed die. When the lower end surface of the metal blank contacts the upper end surface of the lower toothed punch, the metal blank is deformed, and the metal blank gradually fills the cavity of the lower toothed die. After the filling is completed, the upper toothed punch stops moving downward; S4, the lower left cylinder and the lower right cylinder are used to control the lower left connecting plate and the lower right connecting plate to move to the left and right sides respectively, and drive the lower left pull plate and the lower right pull plate to move to the left and right sides. When the middle distance between the lower left pull plate and the lower right pull plate is greater than the tooth top circle diameter of the upper toothed punch, the movement stops, and then the lower toothed punch drives the direction push rod to drop downward, and the lower toothed punch contacts the end surface of the lower groove of the die base; S5. Then, the upper toothed punch continues to move downward to squeeze the formed forging out of the lower toothed concave mold cavity. The forging falls downward onto the upper end surface of the lower toothed punch, and the forging is taken out from the forging material taking ports arranged on the front and rear sides of the die base.

[0013] The beneficial effects of the present invention are: Different from traditional machined gears and half-tooth-depth super-large-module gears, the full-tooth-profile (full-tooth-height) super-large-module spur gear forgings formed by the present invention can ensure that the metal flow lines are distributed along the contour of the parts after machining, and there is basically no cutting and exposure of the metal flow lines, which greatly improves the strength of the gears; the forming device of the present invention overcomes the problem of violent flow of the blank during the forming process of the full-tooth-height super-large-module spur gear forgings, resulting in short die life and large forming force. The present invention divides the forming process into two stages, which are completed by two-stage dies. The upper stage completes the forming of a certain half-tooth-height blank, and the lower stage completes the forming of the full-tooth-height forging. The two-stage dies have low temperature rise and good lubrication, which effectively prevents the die from deformation and failure, improves the die life, and enables full-tooth-height super-large-module spur gear forgings to be formed in batches; the present invention can meet the needs of engineering machinery, marine equipment, and aerospace equipment for high-load super-large-module gears. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A three-dimensional diagram of a full-tooth-height ultra-large-module spur gear forging according to the present invention; Figure 2 Metal flow diagram of full tooth height (full tooth depth) super large modulus spur gear forging; Figure 3 Metal flow diagram of half-depth extra-large modulus spur gear forgings; Figure 4 A schematic diagram of the forming process of the forging of a spur gear with full tooth height and ultra-large modulus; Figure 5 A three-dimensional diagram of a full-tooth-height ultra-large-module spur gear forging forming device (without a die cover plate) of the present invention; Figure 6 Front and sectional view of the full-tooth-height ultra-large-module spur gear forging forming device; Figure 7 A top view of a sectional view of a forming device for a full-tooth-height, ultra-large-module spur gear forging; Figure 8 Schematic diagram of the forming device during the forming process of the full-tooth-height ultra-large-module spur gear forging; Fig. 9 Schematic diagram of the full-tooth-height ultra-large-module spur gear forging being ejected from the die after forming; Fig.10 Comparison diagram of upper toothed die, lower toothed die and blank outline; Fig.11 Schematic diagram of the connection between the upper toothed die and the square ejector pin; Figure numerals: 1, square push rod, 2, die base, 3, left lower pull plate, 4, left lower connecting plate, 5, left lower oil cylinder, 6, left upper connecting plate, 7, left upper oil cylinder, 8, left upper pull plate, 9, stop pin, 10, die cover plate, 11, upper toothed punch, 12, upper toothed die, 13, blank, 14, lower toothed die, 15, lower toothed punch, 16, right upper connecting plate, 17, right upper oil cylinder, 18, right upper pull plate, 19, right lower oil cylinder, 20, right Lower connecting plate, 21, right lower pull plate, 101, half tooth height step, 102, full tooth height step, 103, transition arc, 200, tooth profile contour line of super large modulus gear parts after machining, 201 tooth profile contour line of super large modulus gear forgings with full tooth height, 202, tooth profile contour line of super large modulus gear forgings with half tooth depth, 300, forging discharge port, 401, lower tooth profile die cavity contour line, 402, upper tooth profile die cavity contour line, 403, billet contour line. DETAILED DESCRIPTION

[0015] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is described in detail below in conjunction with specific embodiments. The following embodiments are implemented based on the technical solutions of the present invention, and detailed implementation methods and specific operating procedures are given. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the following embodiments.

[0016] A full-tooth-height super-large modulus spur gear forging, the gear module is 40, the number of teeth is 13, including a half-tooth-height step 101 and a full-tooth-height step 102, and countersunk holes are set on both end faces according to the processing needs of gear parts. The thickness of the half-tooth-height step 101 is not less than the height of the transition arc 103 between the two steps, and the full-tooth-height super-large modulus gear forging tooth profile contour line 201 of the full-tooth-height step 102 is uniformly different from the tooth profile contour line 200 of the super-large modulus gear part after machining (machining amount), and the tooth metal streamline of the full-tooth-height step 102 is distributed along the tooth profile, and the streamline is not cut off or exposed. The half-tooth-height step 101 of the forging is required by the process, and will be fully or partially removed according to the gear part drawing later.

[0017] A full-tooth-height ultra-large-module spur gear forging forming device comprises an upper die assembly, a lower die assembly, a left die assembly, and a right die assembly. The upper die assembly is an upper tooth-shaped punch 11, and the upper tooth-shaped punch 11 is connected to an upper slide of a press through a transfer mechanism. The lower die assembly comprises a square ejector rod 1, a die base 2, a stop pin 9, a die cover plate 10, an upper tooth-shaped die 12, a lower tooth-shaped die 14, and a lower tooth-shaped punch 15. The lower toothed die 14 and the upper toothed die 12 are installed in the circular stepped hole at the upper end of the die base 2 in sequence, the stop pin 9 is inserted into the lower toothed die 14 and the upper toothed die 12 at the outer circle to form a semicircular groove and a circular hole formed by the semicircular groove in the stepped hole of the die base 2, the lower toothed punch 15 is installed in the die cavity of the lower toothed die 14, the lower toothed punch 15 is connected to the square push rod 1, the square push rod 1 is inserted into the square hole on the lower end face of the die base 2, the die cover plate 10 is installed on the upper end of the upper toothed die 12, and is consolidated with the upper end face of the die base 2, so as to fix the upper toothed die 12.

[0018] The left mold assembly includes a left lower pull plate 3, a left lower connecting plate 4, a left lower oil cylinder 5, a left upper connecting plate 6, a left upper oil cylinder 7, and a left upper pull plate 8. The left upper pull plate 8 is inserted into the rectangular hole at the left end of the mold base 2, a rectangular groove is set in the middle of the right side of the left upper pull plate 8, the left side of the left upper pull plate 8 is connected to the left upper connecting plate 6, the left upper connecting plate 6 is connected to the cylinder heads of the left upper oil cylinder 7 at the front and rear ends, and the two left upper oil hydraulic cylinders are installed and fixed in the left square groove of the mold base 2; the left lower pull plate 3 is inserted into the rectangular hole at the left end of the mold base 1, a rectangular groove is set in the middle of the right side of the left lower pull plate 3, the left side of the left lower pull plate 3 is connected to the left lower connecting plate 4, the left lower connecting plate 4 is connected to the cylinder heads of the left lower oil cylinder 5 at the front and rear ends, and the two left lower oil hydraulic cylinders 5 are installed and fixed in the left square groove of the mold base 2. The right mold assembly includes a right lower pull plate 21, a right lower connecting plate 20, a right lower oil cylinder 19, a right upper connecting plate 16, a right upper oil cylinder 17, and a right upper pull plate 18. The right upper pull plate 18 is inserted into the rectangular groove at the right end of the mold base 2, a rectangular groove is set in the middle of the left side of the right upper pull plate 18, the right side of the right upper pull plate 18 is connected to the right upper connecting plate 16, the right upper connecting plate 16 is connected to the cylinder heads of the right upper oil cylinder 17 at the front and rear ends, and the two right upper oil hydraulic cylinders 17 are installed and fixed in the right square groove of the mold base 2; the right lower pull plate 21 is inserted into the rectangular groove at the right end of the mold base 2, a rectangular groove is set in the middle of the left side of the right lower pull plate 21, the right side of the right lower pull plate 21 is connected to the right lower connecting plate 20, the right lower connecting plate 20 is connected to the cylinder heads of the right lower oil cylinder 19 at the front and rear ends, and the two right lower oil hydraulic cylinders 19 are installed and fixed in the right direction hole of the mold base 2.

[0019] In the forming device, the semicircular grooves at the outer circumferences of the upper toothed die 12 and the lower toothed die 14 have a positional relationship with the mold cavities of the toothed die 12 and the lower toothed die 14, which prevents the upper and lower toothed dies from axially rotating and causing tooth misalignment. After the central axis and the semicircular grooves of the upper toothed die 12 and the lower toothed die 14 correspond to each other, the toothed shapes of the upper toothed die 12 and the lower toothed die 14 correspond to each other. The square flange at the head of the square ejector pin 1 is connected to the square positioning groove of the lower toothed punch 15, and the lower part of the square ejector pin is inserted into the square guide rod hole on the lower end face of the die base 2. The position of the square positioning groove should ensure that the lower toothed punch 15 can pass smoothly through the lower toothed die 14. This structure can ensure that the square ejector pin 1 and the lower toothed punch 15 connected thereto will not rotate. The square shape of the square push rod 1 determines the position of the lower toothed punch 15 to prevent axial rotation. This is because the lower toothed punch 15 and the lower toothed die 14 will separate during the forming process, and positioning is required during resetting to prevent interference between the lower toothed die 14 and the lower toothed punch 15.

[0020] In the forming device, the blank contour line 403 is smaller than the tooth top circle of the tooth profile of the upper toothed die cavity by △t1, and △t1 is the expansion amount of the blank after heating plus 1mm. This structure can ensure that the blank is smoothly placed in the cavity of the upper toothed die 12 without destroying the lubricant attached to the tooth root. The lower toothed die cavity contour line 401 of the lower toothed die 14 is larger than the upper toothed die cavity contour line 402 of the upper toothed die 12 by △t2, and △t2 is the expansion amount of the blank after it is ejected from the upper toothed die plus 1mm. This structure can ensure that the blank will not come into contact with the lower toothed die cavity after being ejected from the upper toothed die 12, so that the lubricant attached to it can be retained, which is beneficial to the deformation behavior of the blank in the lower toothed die 14.

[0021] In the forming device, the width of the left upper pull plate 8 and the right upper pull plate 18 is greater than the width of the left lower pull plate 3 and the right lower pull plate 21, and the thickness of the left upper pull plate 8 and the right upper pull plate 18 is equal to the thickness of the gear forging full tooth height step 102. During the plate pulling process, this structure makes the weight of the upper pull plate not fully borne by the lower pull plate, and part of the weight is borne by the groove step of the die base 1, so that the plate pulling is flexible and the pressure of the plate pulling cylinder is stable.

[0022] A forming method for a full-tooth-height ultra-large-module spur gear forging. A forming method for a full-tooth-height ultra-large-module spur gear forging, characterized in that the specific steps are as follows: S1. The forming device is placed in a press with downward pressing and ejecting functions. An external hydraulic system provides kinetic energy for the plate pulling cylinder. The metal blank 13 heated to the hot forging temperature is placed in the die cavity of the lubricated upper toothed die 12. The upper toothed punch 11 moves downward under the action of the press to extrude the metal blank 13. When the metal blank 13 fills the die cavity, the upper toothed punch 11 stops moving. S2, the upper left cylinder 7, and the upper right cylinder 17 are used to control the upper left connecting plate 6 and the upper right connecting edge 16 to move to the left and right sides respectively, and drive the upper left pull plate 8 and the upper right pull plate 18 to move to the left and right sides. When the distance between the upper left pull plate 8 and the upper right pull plate 18 is greater than the diameter of the tooth top circle of the upper toothed punch 11, the movement stops, and then the lower toothed punch 15 drives the square push rod 1 to fall downward, and the lower toothed punch 15 contacts the upper end surfaces of the upper left pull plate 8 and the upper right pull plate 18; S3, the upper toothed punch 11 continues to extrude the metal blank 13, and the metal blank 13 enters the cavity of the lower toothed die 14. When the lower end surface of the metal blank 13 contacts the upper end surface of the lower toothed punch 15, the metal blank 13 is deformed, and the metal blank 13 gradually fills the cavity of the lower toothed die 14. After the filling is completed, the upper toothed punch 11 stops moving downward; S4, the lower left oil cylinder 5, and the lower right oil cylinder 19 are used to control the lower left connecting plate 4 and the lower right connecting plate 20 to move to the left and right sides respectively, and drive the lower left pull plate 3 and the lower right pull plate 21 to move to the left and right sides. When the middle distance between the lower left pull plate 3 and the lower right pull plate 21 is greater than the tooth top circle diameter of the upper toothed punch 11, the movement stops, and then the lower toothed punch 15 drives the square push rod 1 to fall downward, and the lower toothed punch 15 contacts the end surface of the lower groove of the die base 2; S5, then the upper toothed punch 11 continues to move downward to squeeze the formed forging out of the cavity of the lower toothed die 14, and the forging falls downward onto the upper end surface of the lower toothed punch 15, and the forging is taken out from the forging material taking ports 300 arranged on the front and rear sides of the die base 2.

[0023] After the forging is taken out, the upper toothed punch 11 moves upward to reset and cools and lubricates the mold cavity. Then the press ejector cylinder acts on the square ejector rod 1 to move the lower toothed punch 15 upward to reset to the initial position, and then the lower left and lower right cylinders drive the lower left pull plate 3 and the lower right pull plate 21 to reset, and the upper left and upper right cylinders drive the upper left pull plate 8 and the upper right pull plate 18 to reset. Then put a new blank into the upper toothed die 12 cavity and repeat the above actions.

[0024] The above shows and describes the main features, methods of use, basic principles and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements according to actual conditions, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A full-tooth-height ultra-large-module spur gear forging, characterized in that: The invention comprises a half tooth height step (101) and a full tooth height step (102), wherein the thickness of the half tooth height step (101) is not less than the height of the transition arc (103) between two adjacent full tooth height steps (102), the difference between the full tooth height ultra-large modulus gear forging tooth profile line (201) of the full tooth height step (102) and the tooth profile profile line (200) of the ultra-large modulus gear part after machining is uniform, and the tooth profile metal streamlines of the full tooth height step (102) are continuously distributed along the tooth profile.

2. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 1, characterized in that: The invention comprises an upper die assembly, a lower die assembly, a left die assembly and a right die assembly, wherein the upper die assembly is an upper toothed punch (11), and the upper toothed punch (11) is connected to an upper slide block of a press via a transfer mechanism, and the upper toothed punch (11) is used to extrude a metal blank (13) in the lower die assembly, and during the extrusion process, the preparation of a forging is achieved by the left-right movement of the symmetrically arranged left die assembly and the right die assembly.

3. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 2, characterized in that: The lower die assembly comprises a die base (2), a die cover plate (10), an upper toothed die (12), a lower toothed die (14), a stop pin (9), a lower toothed punch (15) and a square ejector pin (1). The lower toothed die (14) and the upper toothed die (12) are sequentially installed in the circular stepped hole at the upper end of the die base (2) from bottom to top. The stop pin (9) is inserted into the outer circumference of the lower toothed die (14) and the upper toothed die (12) to form a semicircular The semicircular groove and the semicircular groove in the stepped hole of the die base (2) form a circular hole. The lower toothed punch (15) is installed in the die cavity of the lower toothed die (14). The bottom of the lower toothed punch (15) is connected to a square push rod (1). The square push rod (1) is inserted into the square hole on the lower end surface of the die base. The die cover plate (10) is installed on the upper end of the upper toothed die (12). The die cover plate (10) is fixed to the upper end surface of the die base (2) and is used to fix the upper toothed die (12).

4. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 3, characterized in that: The central axis and the semicircular groove of the upper toothed die (12) correspond to those of the lower toothed die (14); the tooth shapes of the upper toothed die (12) and the lower toothed die (14) correspond to each other; the square flange at the head of the square push rod (1) is connected to the square positioning groove of the lower toothed punch (15); the lower toothed punch (15) passes through the lower toothed die (14) through the square positioning groove; and the lower end of the square push rod (1) is inserted into the square guide rod hole on the lower end surface of the die base (2).

5. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 2, characterized in that: The left mold assembly comprises a left lower pull plate (3), a left lower connecting plate (4), a left lower oil cylinder (5), a left upper connecting plate (6), a left upper oil cylinder (7) and a left upper pull plate (8). The left lower pull plate (3) and the left upper pull plate (8) are inserted into the rectangular hole at the left end of the mold base (2). A rectangular groove is provided in the middle of the right side of the left upper pull plate (8) and the left lower pull plate (3). The left side of the left upper pull plate (8) is connected to the left upper connecting plate (6). The left upper connecting plate (6) is connected to the left upper pull plate (8). The cylinder heads of the upper left oil cylinder (7) at the front and rear ends of the pull plate (8) are connected, and the two upper left oil cylinders (7) are fixedly installed in the left square groove of the mold base (2); a rectangular groove is arranged in the middle of the right side of the left lower pull plate (3), the left side of the left lower pull plate (3) is connected to the left lower connecting plate (4), the left lower connecting plate (4) is connected to the cylinder heads of the lower left oil cylinder (5) at the front and rear ends of the left lower pull plate (3), and the two lower left oil cylinders (5) are fixedly installed in the left square groove of the mold base (2).

6. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 2, characterized in that: The right mold assembly comprises a right lower pull plate (21), a right lower connecting plate (20), a right lower oil cylinder (19), a right upper connecting plate (16), a right upper oil cylinder (17) and a right upper pull plate (18). The right upper pull plate (18) is inserted into a rectangular groove at the right end of the mold base (2). A rectangular groove is arranged in the middle of the left side of the right upper pull plate (18). The right side of the right upper pull plate (18) is connected to the right upper connecting plate (16). The left upper connecting plate (16) is connected to the right upper oil cylinder (17) at the front and rear ends. The two upper right oil cylinders (17) are installed and fixed in the right square groove of the mold base (2); the right lower pull plate (21) is inserted into the rectangular groove at the right end of the mold base (2); a rectangular groove is arranged in the middle of the left side of the right lower pull plate (21); the right side of the right lower pull plate (21) is connected to the right lower connecting plate (20); the right lower connecting plate (20) is connected to the cylinder heads of the right lower oil cylinders (19) at the front and rear ends; and the two lower right hydraulic cylinders (19) are installed and fixed in the right direction holes of the mold base (2).

7. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 2, characterized in that: The blank contour line (403) of the metal blank (13) is smaller than the tooth top circle of the upper toothed concave mold cavity tooth contour line (402) of the upper toothed concave mold (12) by Δt1, wherein Δt1 is the expansion amount of the blank after heating plus 1 mm; The lower toothed die cavity contour line (401) of the lower toothed die (14) is larger than the upper toothed die cavity contour line (402) by Δt2, wherein Δt2 is the expansion amount of the blank after it is ejected from the upper toothed die plus 1 mm.

8. A forming device for a full-tooth-height ultra-large-module spur gear forging according to claim 5 or 6, characterized in that: The width of the left upper pull plate (8) and the right upper pull plate (18) is greater than the width of the left lower pull plate (3) and the right lower pull plate (21), and the thickness of the left upper pull plate (8) and the right upper pull plate (18) is the same as the full tooth height step (102) of the gear forging.

9. The forming method of a full-tooth-height ultra-large-module spur gear forging according to claim 1, characterized in that: The specific steps are as follows: S1, placing a metal blank (13) heated to a hot forging temperature into a die cavity of a lubricated upper toothed die (12), and the upper toothed punch (11) moves downward under the action of a press to extrude the metal blank (13), and the upper toothed punch (11) stops moving when the metal blank (13) fills the die cavity; S2, the upper left oil cylinder (7) and the upper right oil cylinder (17) are used to control the upper left connecting plate (6) and the upper right connecting plate (16) to move to the left and right sides respectively, and drive the upper left pull plate (8) and the upper right pull plate (18) to move to the left and right sides. When the distance between the upper left pull plate (8) and the upper right pull plate (18) is greater than the diameter of the tooth top circle of the upper toothed punch (11), the movement stops, and then the lower toothed punch (15) drives the square push rod (1) to drop downward, and the lower toothed punch (15) contacts the upper end surfaces of the upper left pull plate (8) and the upper right pull plate (18); S3, the upper toothed punch (11) continues to extrude the metal blank (13), and the metal blank (13) enters the cavity of the lower toothed die (14). When the lower end surface of the metal blank (13) contacts the upper end surface of the lower toothed punch (15), the metal blank (13) is deformed, and the metal blank (13) gradually fills the cavity of the lower toothed die (14). After the filling is completed, the upper toothed punch (11) stops moving downward; S4, the lower left oil cylinder (5) and the lower right oil cylinder (19) are used to control the lower left connecting plate (4) and the lower right connecting plate (20) to move to the left and right sides respectively, and drive the lower left pull plate (3) and the lower right pull plate (21) to move to the left and right sides. When the middle distance between the lower left pull plate (3) and the lower right pull plate (21) is greater than the tooth top circle diameter of the upper toothed punch (11), the movement stops, and then the lower toothed punch (15) drives the square push rod (1) to drop downward, and the lower toothed punch (15) contacts the end surface of the lower groove of the die base (2); S5. Then, the upper toothed punch (11) continues to move downward to extrude the formed forging from the cavity of the lower toothed die (14). The forging falls downward onto the upper end surface of the lower toothed punch (15), and the forging is taken out from the forging material taking ports (300) arranged on the front and rear sides of the die base (2).

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