Method and device for evaluating tooth shape forming limit of high-strength steel gear hub part

Abstract

The invention relates to a tooth forming limit evaluation method and device for a high-strength steel gear hub tooth-shaped part, which is used for performing a tooth forming limit evaluation test on a hydraulic machine and comprises an upper template capable of moving up and down, an upper die provided with a convex die and a lower die correspondingly arranged on a lower template, the lower die is a group of female dies which are spliced by symmetrical insert structures and provided with downward notches, a reverse ejector rod and a reverse ejector block are arranged on the lower die, each group of inserts of the female dies are provided with three or more odd tooth profiles, and a central tooth profile 2 located in the center is of a three-section type composite tooth profile structure and comprises a tooth profile depth evaluation section 1, a tooth profile depth evaluation section 2, a tooth profile depth evaluation section 3, a tooth profile depth evaluation section 4 and a tooth profile depth evaluation section 5, the tooth profile width evaluation section 2 is used for comprehensively evaluating the tooth profile width, the tooth profile width can be changed from b to B, and the fillet evaluation section 3 is used for gradually transitioning the fillet from R to r. According to the method, the tooth-shaped formability can be evaluated quickly and accurately, and the tooth-shaped depth, the tooth-shaped width and the tooth-shaped fillet limit size are obtained.

Description

Technical Field

[0001] The present invention relates to sheet metal forming in the field of metallurgy, and more particularly to a method and device for evaluating the tooth forming limit of high-strength steel gear hub parts. Background Art

[0002] Geared components, such as clutch hubs, are core components in automotive transmissions. They transmit motion and load, ensuring smooth shifting and proper operation. These components are axisymmetric housings with regularly spaced internal and external teeth. The tooth profiles vary in shape and size depending on the functional design and transmission requirements. Due to the high demands placed on these components, forming precision is crucial, and the quality of these forming processes directly impacts the performance and lifespan of the automotive clutch.

[0003] Due to the complex shape and forming process of such parts, conventional FLC, cupping and other material forming limit assessment methods or forming performance simulation assessment methods cannot quickly, directly and effectively determine whether the part tooth profile is formable, and the tooth profile forming limit dimensions under different materials.

[0004] Traditionally, these parts have been made of mild steel, which offers low strength and good formability. Following the tooth profile design, good forming quality and a good tooth shape can be achieved based on experience. However, with increasing demands for lightweighting and performance, higher-strength high-strength steels have been gradually adopted for these parts in recent years. However, with this increase in strength, tooth formability and quality face more challenges and design blind spots. One of these challenges is determining the forming limit dimensions of the high-strength steel tooth profile to better guide product design and material selection. Therefore, a method to evaluate the formability of high-strength steel tooth profile parts is urgently needed in this field to address the application of high-strength steel in these parts. Summary of the Invention

[0005] To this end, the present invention proposes a method and device for evaluating the tooth forming limits of high-strength steel gear hub-type toothed parts, so as to quickly and accurately evaluate the dimensional limits and adaptability of different materials during tooth forming of such parts, thereby filling the gap in the evaluation of high-strength steel tooth forming limits and having extremely important guiding significance for the design, material selection, material performance control and stable production of such parts.

[0006] The technical solution of the tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts of the present invention is as follows:

[0007] A tooth profile forming limit evaluation device for high-strength steel gear hub-type toothed parts is used to perform tooth profile forming limit evaluation tests on a hydraulic press, and is characterized in that:

[0008] The tooth profile forming limit evaluation device comprises:

[0009] Placed on the upper mold plate that can move up and down, with a punch and

[0010] The corresponding lower mold is placed on the lower template.

[0011] The lower die is a set of concave dies with a symmetrical insert structure and a downward notch, with a counter-ejector rod and a counter-ejector block on top.

[0012] Each set of inserts in the die has three or more odd-numbered tooth profiles. The central tooth profile 2 located in the center is the core structure for tooth profile evaluation, which is used to evaluate tooth formability or material adaptability.

[0013] The center tooth profile 2 is a "3-segment" composite tooth profile structure, including:

[0014] Tooth depth evaluation section 1 for comprehensive evaluation of tooth depth of toothed parts, depth is H,

[0015] Tooth profile width evaluation section 2 for comprehensive evaluation of tooth profile width, where the tooth profile width can be changed from b to B, and

[0016] Fillet evaluation section 3 is used to comprehensively evaluate the three core size limits of tooth fillet, and the fillet gradually transitions from R to r.

[0017] According to the present invention, a tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts is characterized in that:

[0018] In tooth profile depth assessment section 1, the tooth profile depth can be deepened to H: 4-7 mm;

[0019] In tooth profile width evaluation section 2, the tooth profile widths b and B in this section are respectively in the range of b: 5-15mm and B: 15-25mm;

[0020] In the fillet evaluation section 3, the fillet gradually transitions from R to r, r is 0-0.5 mm, and R is 1-2 mm.

[0021] According to the present invention, a tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts is characterized in that:

[0022] A width adjustment block and a depth adjustment block are respectively provided in the middle and bottom of the center tooth shape of each insert, for adjusting the width and thickness of the center tooth shape of the insert respectively.

[0023] According to the tooth forming limit evaluation device of a high-strength steel hub-type toothed part described in the present invention, it is characterized in that the width adjustment block and the depth adjustment block are respectively inserted into the middle part of the center tooth block and the bottom of the tooth in the form of vertical sheets.

[0024] According to the tooth forming limit evaluation device for high-strength steel hub-type toothed parts described in the present invention, it is characterized in that each group of inserts in the die has three tooth shapes, and a first auxiliary forming tooth shape and a second auxiliary forming tooth shape are provided on both sides of the center tooth shape 2.

[0025] A method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed part, wherein the tooth profile forming limit evaluation device according to claim 1 is placed on a hydraulic press, and a cylindrical preform is subjected to a deep drawing or spinning process to perform a tooth profile forming limit evaluation test, characterized in that:

[0026] Step 1): The press uses a push rod 10 to drive the anti-elevator 9 and the anti-elevator block 7 to a high position, and places the blank on the anti-elevator block 7 to achieve the positioning of the blank;

[0027] Step 2): Subsequently, the upper die moves downward, driving the punch 20 to move downward, pushing the counter-top block 7 downward together. During the downward process, the hydraulic press provides a constant counter-top force;

[0028] Step 3): The counter-top block moves smoothly downward under the action of the positioning guide groove of the outer ring of the die to the accurate position of the evaluation test setting;

[0029] Step 4): Open the mold, and use the unloading plate to complete the unloading action of the internal and external gear parts, remove the test blank and measure the evaluation dimensions.

[0030] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0031] In the tooth profile depth assessment section, the tooth profile depth gradually deepens to the limit height H, and the tooth profile width and fillet remain fixed in this section;

[0032] In the tooth profile width evaluation section, the tooth profile width changes from b to the limit B, and the tooth profile depth and fillet remain fixed;

[0033] In the fillet evaluation section, the fillet gradually transitions from R to the limit fillet r.

[0034] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0035] In the tooth profile depth assessment section, the tooth profile depth can be deepened to H: 4~7mm.

[0036] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0037] In the tooth profile width evaluation section, the tooth profile widths b and B in this section are: b is 5 to 15 mm, and B is 15 to 25 mm;

[0038] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0039] In the fillet evaluation section, the fillet gradually transitions from R to the extreme fillet r, where r is 0 to 0.5 mm and R is 1 to 2 mm.

[0040] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0041] Each set of inserts in the die has three tooth shapes, and a first auxiliary forming tooth shape and a second auxiliary forming tooth shape are provided on both sides of the central tooth shape.

[0042] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0043] During the evaluation process, the tooth profile is first formed to the first depth limit H, and the crack position is observed and measured. If the crack occurs at the tooth depth h1, the insert depth adjustment block is replaced to reduce the tooth profile limit depth from H to h1;

[0044] Carry out the second test again, forming to the second limit width B, observe and measure the crack position, if the crack position is at width b1, adjust the width adjustment block to make the tooth width limit b1;

[0045] The third test was conducted, forming to the limit of the fillet, and the size of the fillet r1 at the crack was observed and measured.

[0046] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0047] The upper die drives the punch to move downward, pushing the counter-elevator block downward together, providing a constant counter-elevation force of 5 to 25 kN.

[0048] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0049] The upper die drives the punch downward, pushing the counter-elevator downward together, providing a constant counter-elevation force of 10kN.

[0050] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0051] The inserts are made of SKD11, CR12MOV and above grade mold materials, and the surface is heat treated with TD, PVD or PVC.

[0052] According to the present invention, a method for evaluating the tooth forming limit of a high-strength steel hub-type toothed part is characterized in that:

[0053] During the evaluation process, the first test is performed to the first depth limit, H. The cracking location is observed and measured. If the crack occurs at the tooth depth h1, the insert depth adjustment block is replaced to reduce the tooth profile depth limit from H to h1. A second test is then performed, forming the second limit, B. The cracking location is observed and measured. If the crack occurs at the width b1, the width adjustment block is adjusted to reduce the tooth profile width limit to b1. A third test is then performed, forming the corner radius limit, r1, to be observed and measured.

[0054] h1 and b1 are usually placed somewhere between the first and second paragraphs.

[0055] In tooth profile depth evaluation section 1, the height H of the gradually deepening tooth profile depth is preferably 4 to 7 mm; in tooth profile width evaluation section 2, the tooth profile widths b and B in this section are preferably in the range of 5 to 15 mm and 15 to 25 mm;

[0056] In the fillet evaluation section 3, the fillet gradually transitions from R to r, r is 0 to 0.5, and R is 1 to 2 mm.

[0057] According to the present invention, the core components of the evaluation method are Figure 1 The die shown in the figure uses a symmetrically joined insert structure. To ensure symmetrical constraints, two sets of die inserts are used. This symmetrical structure ensures uniform force and deformation flow during the evaluation test, reducing test errors caused by uneven material flow.

[0058] According to the present invention, each set of inserts in the die has three tooth profiles (or an odd number greater than three). The central tooth profile 2, located in the center, is the core feature for tooth profile evaluation; its formability is used to assess tooth formability and material adaptability. The tooth profiles on either side serve as the first and second auxiliary forming profiles, respectively. These ensure that both sides of the central tooth profile 2 are simultaneously forming during the forming process, thereby ensuring that the deformation pattern of the central tooth profile 2 is consistent with the actual part forming process.

[0059] According to the present invention, the central tooth profile evaluation feature is a "3-segment" composite tooth profile structure, such as Figure 2As shown. By using this composite structure, the limits of the three core dimensions of the tooth profile part, namely, tooth depth, tooth width, and tooth fillet, can be comprehensively evaluated in a set of tooling through only three evaluation tests. Among them, segment 1 is the tooth profile depth evaluation area, where the tooth profile depth gradually deepens to height H, and the tooth profile width and fillet in this section remain fixed; segment 2 is the tooth profile width evaluation area, where the tooth profile width changes from b to B, and the tooth profile depth and fillet in this section remain fixed; segment 3 is the fillet evaluation area, where the fillet gradually transitions from R to r. Among them, H is 4-7mm; b is 5-15mm, B is 15-25mm; r is 0-0.5, and R is 1-2mm; the optimized ones are H=5mm, b=5mm, B=18mm, R=2mm, and r=0.5mm.

[0060] According to the present invention, in the middle and bottom of each insert center tooth shape, there are size adjustment blocks, which are width adjustment blocks and depth adjustment blocks, such as Figure 3 As shown. During the evaluation process, the forming process begins at the first depth limit, H, and the cracking location is observed and measured. If cracking occurs at tooth depth h1, the insert depth adjustment block is replaced (i.e., after replacing inserts of appropriate thickness, ensure that the maximum tooth height H' ≤ h1 to prevent cracking at this depth). This reduces the tooth profile's limit depth from H to h1. A second test is then conducted, forming to the second limit, B, and the cracking location is observed and measured. If the cracking location is at width b1, the width adjustment block is adjusted to reduce the tooth profile's limit width to b1. A third test is then conducted, forming to the corner radius limit, and the radius r1 at the cracking location is observed and measured. h1, b1, and r1 are then the limit dimensions of the tooth profile formed for this material.

[0061] According to the present invention, the evaluation test will use a cylindrical prefabricated part, which can be formed by deep drawing or spinning, or other processes that can meet the requirements of roundness and thickness uniformity of the prefabricated part.

[0062] According to the present invention, Figure 4 To evaluate the experimental setup, the device was placed on a hydraulic press for evaluation testing. During the evaluation test, the press's ejector pin 10 drove the counter-ejector pin 9 and counter-ejector block 7 to their highest position. The blank was then placed on the counter-ejector block 7, where it was positioned using the small bosses. The upper die's punch 20 was positioned by the upper punch retaining ring 15 and the punch retaining ring 18.

[0063] The upper die then descends, driving the punch 20 downward and pushing the counter-ejector block 7 downward with it. During this downward movement, the hydraulic press provides a constant counter-ejector force. Guided by the positioning guide grooves on the outer ring of the die, the counter-ejector block moves smoothly downward to the precise position for the evaluation test setup.

[0064] After the evaluation test is complete, the upper die moves upward to open the mold, and the stripper plate completes the unloading of the toothed parts. The test piece is removed and the dimensions to be evaluated are measured. The unloading of internal and external toothed parts is completed by the stripper plate 22 and the stripper stop plate 14 via the unloading guide pins and guide sleeves.

[0065] Remove the test piece and measure the dimensions to be evaluated.

[0066] According to a method and tooling device for evaluating the tooth profile forming limits of gear hub parts of the present invention, a specially designed three-section composite tooth profile structure feature can be used to quickly and accurately evaluate the tooth profile forming properties in a set of tooling, obtain the tooth profile depth, tooth profile width, and tooth profile fillet limit dimensions, and also evaluate the material adaptability, thereby solving the problem of the lack of evaluation methods for the tooth profile forming limits and material adaptability of such parts. This has extremely important guiding significance for the design, material selection, material performance control and stable production of such parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 The figure shows the schematic diagram of the symmetrical insert splicing structure die.

[0068] Figure 2 This is a schematic diagram of a three-section composite tooth structure die.

[0069] Figure 3 It is a "3-section" composite die structure.

[0070] Figure 4 To evaluate the assembly diagram of the experimental setup,

[0071] Figure 5 The figure shows the working status of the upper and lower molds installed on the double-action hydraulic press.

[0072] Figure 6 For the formed cylindrical preform,

[0073] Figure 7 This is the state diagram of the part after testing. DETAILED DESCRIPTION

[0074] like Figure 5 As shown, the gear hub parts tooth forming limit evaluation device is installed on a double-action hydraulic press, and the press drives the anti-thrust rod 9 to the high position through the press push rod 10, and the formed cylindrical preform ( Figure 6 ) is placed on the counter-top block, and the small boss is used to position the blank. Subsequently, the upper die moves downward, driving the punch 20 to move downward, pushing the counter-top block downward together.

[0075] During the downward movement, a constant counter-thrust force of 10 kN is provided. The counter-thrust block moves downward steadily under the action of the positioning guide groove of the outer ring 5 of the die, and the punch 20 of the upper die is positioned by the upper punch positioning ring 15 and the punch positioning ring 18.

[0076] The upper die then descends, driving the punch 20 downward and pushing the counter-ejector block 7 downward with it. During this downward movement, the hydraulic press provides a constant counter-ejector force. Guided by the positioning guide grooves on the outer ring of the die, the counter-ejector block moves smoothly downward to the precise position for the evaluation test setup.

[0077] After the evaluation test is completed, the upper die moves upward to open the die, and the unloading plate 22 and the unloading limit plate 14 complete the unloading action of the internal and external gear parts through the unloading guide pins and guide sleeves.

[0078] Remove the test piece and measure the dimensions to be evaluated.

[0079] The tooth profile forming limit evaluation device comprises:

[0080] A set of symmetrical inserts in a die. Each set of inserts in the die has three tooth shapes. The center tooth shape 2 is the core structure for tooth shape evaluation, used to evaluate tooth shapeability or material adaptability.

[0081] The center tooth profile 2 is a "3-segment" composite tooth profile structure, including: tooth profile depth evaluation segment 1 for comprehensive evaluation of the tooth profile depth of the tooth profile parts, tooth profile width evaluation segment 2 for comprehensive evaluation of the tooth profile width, and fillet evaluation segment 3 for comprehensive evaluation of the three core size limits of the tooth profile fillet.

[0082] The inserts are made of SKD11, CR12MOV and above grade mold materials, and the surface is heat treated by TD, PVD or PVC to reduce the influence of tooling wear and friction during the forming test on the test results.

[0083] In tooth profile depth evaluation section 1, the height H of the gradually deepening tooth profile depth is preferably 4 to 7 mm; in tooth profile width evaluation section 2, the tooth profile widths b and B in this section are preferably in the range of 5 to 15 mm and 15 to 25 mm;

[0084] In the fillet evaluation section 3, the fillet gradually transitions from R to r, r is 0 to 0.5, and R is 1 to 2 mm.

[0085] The optimized values ​​are H=5mm, b=5mm, B=18mm, R=2mm, and r=0.5mm.

[0086] In the middle and bottom of each insert center tooth, there are size adjustment blocks, namely width adjustment block and depth adjustment block, such as Figure 3As shown (the width adjustment block is inserted vertically into the center of the insert tooth profile, and the depth adjustment block is placed at the bottom of the insert tooth profile). During the evaluation process, the tool is first formed to the first depth limit H. The cracking location is observed and measured. If cracking occurs at tooth depth h1, the tool depth adjustment block is replaced (i.e., after replacing the insert with the appropriate thickness, ensure that the maximum tooth height H' ≤ h1 to prevent cracking at this depth). This reduces the maximum depth of the tooth profile from H to h1. A second test is then conducted, forming to the second limit B. The cracking location is observed and measured. If the cracking location is at width b1, the width adjustment block is adjusted to reduce the maximum width of the tooth profile to b1. A third test is then conducted, forming to the fillet limit. The radius r1 at the cracking location is observed and measured. h1, b1, and r1 are then the maximum dimensions of the formed tooth profile for this material.

[0087] The tooth profile forming limit evaluation method and tooling device for hub-type parts proposed in the present invention can evaluate the tooth profile formability relatively quickly and accurately, obtain the tooth profile depth, tooth profile width, and tooth profile fillet limit dimensions, and can also evaluate the material adaptability, solving the problem of the lack of tooth profile forming limit and material adaptability evaluation methods for such parts. It has extremely important guiding significance for the design, material selection, material performance control and stable production of such parts.

Claims

1. A tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts, used for performing tooth profile forming limit evaluation tests on a hydraulic press, characterized in that: The tooth profile forming limit evaluation device comprises: Placed on the upper mold plate that can move up and down, with a punch and The corresponding lower mold is placed on the lower template. The lower die is a set of concave dies with a symmetrical insert structure and a downward notch, with a counter-ejector rod and a counter-ejector block on top. Each set of inserts in the die has three or more odd-numbered tooth profiles. The central tooth profile located in the center is the core structure for tooth profile evaluation, which is used to evaluate tooth formability or material adaptability. The center tooth profile is a "3-segment" composite tooth profile structure, including: The tooth depth evaluation section is used to comprehensively evaluate the tooth depth of toothed parts. The depth is H. The tooth profile width evaluation section is used to comprehensively evaluate the tooth profile width. The tooth profile width can be changed from b to B, and The fillet evaluation section is used to comprehensively evaluate the three core size limits of the tooth fillet, and the fillet gradually transitions from R to r.

2. The tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts according to claim 1, characterized in that: In the tooth profile depth assessment section, the tooth profile depth can be deepened to H: 4-7 mm; In the tooth profile width evaluation section, the tooth profile widths b and B in this section are respectively b: 5~15mm, B: 15~25mm; In the fillet evaluation section, the fillet gradually transitions from R to r, r is 0-0.5 mm, and R is 1-2 mm.

3. The tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts according to claim 1, characterized in that: A width adjustment block and a depth adjustment block are respectively provided in the middle and bottom of the center tooth shape of each insert, for adjusting the width and thickness of the center tooth shape of the insert respectively.

4. The tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts according to claim 1, characterized in that: The width adjustment block and the depth adjustment block are respectively inserted into the middle part and the bottom part of the central tooth shape of the insert block in the form of vertical sheets.

5. The tooth profile forming limit evaluation device for high-strength steel hub-type toothed parts according to claim 1, characterized in that: Each set of inserts in the die has three tooth shapes, and a first auxiliary forming tooth shape and a second auxiliary forming tooth shape are provided on both sides of the central tooth shape.

6. A method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component, wherein the tooth profile forming limit evaluation device according to claim 1 is placed on a hydraulic press, and a cylindrical preform is subjected to a deep drawing or spinning process to perform a tooth profile forming limit evaluation test, characterized in that: Step 1): The press uses a push rod (10) to drive the counter push rod (9) and the counter push block (7) to a high position, and places the blank on the counter push block (7) to achieve the positioning of the blank; Step 2): Subsequently, the upper die moves downward, driving the punch (20) to move downward, pushing the counter-top block (7) downward together. During the downward process, the hydraulic press provides a constant counter-top force; Step 3): The counter-top block moves smoothly downward under the action of the positioning guide groove of the outer ring of the die to the accurate position of the evaluation test setting; Step 4): Open the mold, and use the unloading plate to complete the unloading action of the internal and external gear parts, remove the test blank and measure the evaluation dimensions.

7. A method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, characterized in that: In the tooth profile depth assessment section, the tooth profile depth gradually deepens to the limit height H, and the tooth profile width and fillet remain fixed in this section; In the tooth profile width evaluation section, the tooth profile width changes from b to the limit B, and the tooth profile depth and fillet remain fixed; In the fillet evaluation section, the fillet gradually transitions from R to the limit fillet r.

8. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: In the tooth profile depth assessment section, the tooth profile depth can be deepened to H: 4~7mm.

9. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: In the tooth profile width evaluation section, the tooth profile widths b and B in this section are respectively: b is in the range of 5 to 15 mm, and B is in the range of 15 to 25 mm.

10. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: In the fillet evaluation section 3, the fillet gradually transitions from R to the extreme fillet r, where r is 0 to 0.5 mm and R is 1 to 2 mm.

11. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: Each set of inserts in the die has three tooth shapes, and a first auxiliary forming tooth shape and a second auxiliary forming tooth shape are provided on both sides of the central tooth shape.

12. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: During the evaluation process, the tooth profile is first formed to the first depth limit H, and the crack position is observed and measured. If the crack occurs at the tooth depth h1, the insert depth adjustment block is replaced to reduce the tooth profile limit depth from H to h1; Carry out the second test again, forming to the second limit width B, observe and measure the crack position, if the crack position is at width b1, adjust the width adjustment block to make the tooth width limit b1; The third test was conducted, forming to the limit of the fillet, and the size of the fillet r1 at the crack was observed and measured.

13. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 6, wherein: The upper die drives the punch to move downward, pushing the counter-elevator block downward together, providing a constant counter-elevation force of 5 to 25 kN.

14. The method for evaluating the tooth profile forming limit of a high-strength steel hub-type toothed component according to claim 13, wherein: The upper die drives the punch downward, pushing the counter-elevator downward together, providing a constant counter-elevation force of 10kN.

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