Die for bending forming of special-shaped thin-wall part and using method

Abstract

The invention discloses a die for bending forming of a special-shaped thin-wall part and a using method, the special-shaped thin-wall part comprises an annular sheet plate (10), a plurality of outer spokes (11) evenly distributed in the circumferential direction are arranged on the outer side of the sheet plate (10), two inner spokes (12) symmetrically distributed about the axis of the sheet plate (10) are arranged on the inner side of the sheet plate (10), and the die comprises an upper die body (20), a middle die body (30) and a lower die body (40); the lower end of the upper die (20) shrinks inwards to form a shaft neck (21), and positioning grooves (23) are formed in the two sides of the lower end of the shaft neck (21). The upper die (20) is of a tubular structure, an annular receding groove (31) is formed in an inner hole in the upper end of the middle die (30), and the outer diameter of the middle die (30) is larger than that of the upper die (20). The lower die (40) is of a tubular structure. The method has the advantages of being low in manufacturing cost, short in manufacturing period and high in retainer machining qualification rate.

Description

Technical Field

[0001] The invention belongs to the field of shaft sealing components of plunger pumps, and in particular relates to a mold for bending a special-shaped thin-walled part into a shaft sealing component retaining frame and a use method thereof. Background Art

[0002] As shown in Figure 4, it is a retainer of the shaft seal component of the plunger pump. The retainer is formed by stamping the special-shaped thin-walled part shown in Figure 3. The special-shaped thin-walled part includes an annular plate. The outer side of the plate is provided with six outer spokes evenly distributed in the circumference, and the inner side of the plate is provided with two inner spokes symmetrically distributed about the axis of the plate. The stamping directions of the outer spokes and the inner spokes are axially opposite. The inner spokes are bent from the root, that is, after the inner spokes are bent, the inner side walls of the inner spokes are on the inner circle of the plate. The outer spokes are bent from the root to a small distance outward, that is, after the outer spokes are bent, the outer side walls of the outer spokes are located outside the outer circle of the plate.

[0003] The existing cage is formed on a punch press using a special bending die. The forming process is to place the blank in a special die, use the punch of the punch press to punch the upper die of the special die, so that it generates vertical downward pressure, and the upper die stamping surface moves to the lower die positioning surface, so that the part is bent and deformed to obtain the finished cage.

[0004] The special bending die can obtain the finished retainer by punching the blank once, and can complete the automatic loading and unloading of the retainer, with high processing efficiency. However, since two bending strips in different directions need to be bent at one time, a very complex linkage mechanism needs to be set up inside the special bending die to convert the downward punching force of the punch press into two different upward forces, one of which acts on the first bending strip and the other acts on the second bending strip. This leads to a complex structure of the special bending die, high production cost, and a relatively long production cycle, which is not conducive to the production of small batches of products and rapid delivery. Summary of the invention

[0005] The purpose of the present invention is to provide a die and a method for using the die for bending and forming special-shaped thin-walled parts. The present invention has the advantages of low production cost, short production cycle and high qualified rate of processed cages.

[0006] The technical solution of the present invention is a mold for bending and forming special-shaped thin-walled parts, wherein the special-shaped thin-walled parts include an annular plate, the outer side of the plate is provided with a plurality of outer spokes evenly distributed in the circumferential direction, and the inner side of the plate is provided with two inner spokes symmetrically distributed about the axis of the plate, characterized in that: the mold includes an upper mold, a middle mold and a lower mold;

[0007] The lower end of the upper die shrinks inward to form a journal, and positioning grooves are provided on both sides of the lower end of the journal;

[0008] The upper die is a tubular structure, the inner diameter of the middle die matches the outer diameter of the journal, the length of the middle die is greater than the length of the journal, an annular avoidance groove is provided at the inner hole at the upper end of the middle die, and the outer diameter of the middle die is greater than the outer diameter of the upper die;

[0009] The lower die is a tubular structure, the inner diameter of the lower die matches the outer diameter of the middle die, and the length of the lower die exceeds the length of the middle die.

[0010] In the aforementioned mold for bending and forming special-shaped thin-walled parts, the mold also includes a screw, the upper mold is a tubular structure, and the inner side of the shaft neck is provided with an internal thread that cooperates with the screw.

[0011] In the aforementioned mold for bending and forming special-shaped thin-walled parts, the journal matches the inner hole of the sheet plate, the outer diameter of the upper mold is larger than the inner diameter of the sheet plate, the difference between the inner hole diameter of the lower mold and the outer diameter of the upper mold is equal to the thickness of the outer spoke, the difference between the diameter of the avoidance groove and the outer diameter of the journal is equal to the thickness of the inner spoke, and the width of the positioning groove matches the width of the inner spoke.

[0012] In the aforementioned die for bending and forming special-shaped thin-walled parts, the sum of the depth of the avoidance groove and the thickness of the sheet is less than the length of the journal.

[0013] In the aforementioned mold for bending and forming special-shaped thin-walled parts, the screw includes a screw rod that cooperates with an internal thread, and a head is provided at the lower end of the screw rod. The sum of the head thickness, the middle mold length, the sheet thickness, and the bending length of the outer spoke is less than the length of the lower mold.

[0014] In the aforementioned die for bending and forming special-shaped thin-walled parts, the depth of the avoidance groove is greater than the bending length of the inner spoke.

[0015] In the aforementioned mold for bending and forming special-shaped thin-walled parts, the lower end of the middle mold is inserted into the upper end of the lower mold, the lower ends of the middle mold and the lower mold are both closed, and the bottom of the middle mold is provided with a compression spring connected to the lower mold, and the outer side wall of the lower mold is provided with a vertical guide hole, and a guide pin fixed to the side wall of the middle mold is provided in the guide hole.

[0016] The method for using the aforementioned mold for bending and forming special-shaped thin-walled parts comprises the following steps in sequence:

[0017] a. Put the plate on the journal of the upper die and make the inner spoke 12 enter the positioning groove.

[0018] b. Put the middle die onto the journal of the upper die to form a first assembly, and place the first assembly on a press for stamping.

[0019] c. Assemble the screws to the upper die so that the sheet is pressed between the upper die and the middle die to form the second assembly.

[0020] d. Put the lower die 40 on the middle die to form a third assembly, and place the third assembly on a press for stamping to obtain a finished product.

[0021] The method for using the aforementioned mold for bending and forming special-shaped thin-walled parts comprises the following steps in sequence:

[0022] e. Put the plate on the journal of the upper die and make the inner spoke 12 enter the positioning groove.

[0023] f. Insert the journal of the upper mold into the inner hole of the middle mold to obtain the assembled mold.

[0024] g. Place the assembled mold on a press for stamping to obtain the finished product.

[0025] Compared with the prior art, the present invention has a simple structure, a small number of parts, and the parts are easy to process, so that the production cost is low and the production cycle is relatively short, which is conducive to the production of small batches of products and rapid delivery.

[0026] During the use of the mold, the sheet is not pressed and fixed when the inner spokes are bent, which further simplifies the structure of the mold. Since the number of inner spokes is small, the sheet will not be deformed when bending, so this simplification will not lead to a decrease in the qualified rate of the resulting retainer; when bending the inner spokes, the sheet can be pressed to avoid the decrease in the qualified rate of the retainer caused by the deformation of the sheet, and the structure of pressing the sheet is also quite simple, which has little impact on the production cost and production cycle. According to practice, the qualified rate of the retainer made by the mold of the present invention is basically the same as the qualified rate of the retainer made by the existing special mold.

[0027] In summary, the present invention has the advantages of low manufacturing cost, short manufacturing cycle and high qualified rate of processed retainers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the explosion of Example 1.

[0029] Figure 2 It is a schematic diagram of the steps when the mold of Example 1 is used to bend parts.

[0030] Figure 3 It is a top view of a special-shaped thin-walled part.

[0031] Figure 4 It is a top view schematic diagram of the retainer formed after bending the special-shaped thin-walled part.

[0032] Figure 5 It is a structural schematic diagram of Example 2.

[0033] Figure 6 It is a schematic diagram of the steps when the mold of Example 2 is used to bend parts.

[0034] The markings in the accompanying drawings are: 10-plate, 11-outer spoke, 12-inner spoke; 20-upper die, 21-shaft neck, 22-inner thread, 23-positioning groove; 30-middle die, 31-avoidance groove, 32-guide pin; 40-lower die, 41-guide hole, 50-screw, 51-screw, 52-protrusion, 60-compression spring. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0036] Example 1. A mold for bending and forming special-shaped thin-walled parts, such as Figure 1 As shown, the special-shaped thin-walled part comprises an annular plate 10, the outer side of the plate 10 is provided with a plurality of outer spokes 11 evenly distributed in the circumferential direction, and the inner side of the plate 10 is provided with two inner spokes 12 symmetrically distributed about the axis of the plate 10. The mold is used to bend the special-shaped thin-walled part into a retainer.

[0037] The mold includes an upper mold 20, a middle mold 30, a lower mold 40 and screws 50;

[0038] The upper die 20 is a tubular structure. The lower end of the upper die 20 contracts inward to form a shaft neck 21 . An internal thread 22 cooperating with the screw 50 is provided on the inner side of the shaft neck 21 . Positioning grooves 23 are provided on both sides of the lower end of the shaft neck 21 .

[0039] The middle mold 30 is a tubular structure, the inner diameter of the middle mold 30 matches the outer diameter of the shaft neck 21, the length of the middle mold 30 is greater than the length of the shaft neck 21, an annular avoidance groove 31 is provided at the inner hole at the upper end of the middle mold 30, and the outer diameter of the middle mold 30 is greater than the outer diameter of the upper mold 20.

[0040] The lower die 40 is a tubular structure, and the inner diameter of the lower die 40 matches the outer diameter of the middle die 30 so that the lower die 40 and the middle die 30 remain coaxial.

[0041] The journal 21 cooperates with the inner hole of the sheet plate 10, the outer diameter of the upper mold 20 is larger than the inner diameter of the sheet plate 10, the difference between the inner hole diameter of the lower mold 40 and the outer diameter of the upper mold 20 is equal to the thickness of the outer spoke 11, the difference between the diameter of the avoidance groove 31 and the outer diameter of the journal 21 is equal to the thickness of the inner spoke 12, and the width of the positioning groove 23 cooperates with the width of the inner spoke 12.

[0042] The sum of the depth of the avoidance groove 31 and the thickness of the plate 10 is smaller than the length of the journal 21 .

[0043] The screw 50 includes a screw rod 51 matched with the internal thread 22 , and a head 52 is provided at the lower end of the screw rod 51 . The sum of the thickness of the head 52 , the length of the middle mold 30 , the thickness of the sheet 10 , and the bending length of the outer spoke 11 is less than the length of the lower mold 40 .

[0044] The depth of the avoidance groove 31 is greater than the bending length of the inner spoke 12 .

[0045] Method of use of Example 1: Figure 2 As shown,

[0046] Step 1: Sleeve the sheet plate 10 onto the journal 21 of the upper mold 20, and the inner spokes enter the positioning grooves 23, so that the sheet plate 10 is limited in the horizontal direction and does not rotate.

[0047] Step 2: The middle die 30 is put on the journal 21 of the upper die 20 to form a first assembly, and the first assembly is placed on a press, and the press presses the upper die 20 downward, and the inner spokes 12 are bent downward and enter the avoidance grooves 31. Since only two inner spokes 12 are bent, the punching force on the sheet 10 is small, and it will not warp and deform, and the sheet 10 does not need to be pressed and fixed.

[0048] Step 3: Assemble the screw 50 into the internal threaded hole of the upper mold 20 and tighten it. The sheet 10 is pressed between the upper mold 20 and the middle mold 30 to form a second assembly.

[0049] Step 4: Put the lower die 40 on the middle die 30 to form a third assembly, and place the third assembly on the press. The press presses the upper die 20 downward, and the outer spokes 11 bend upward and enter the gap between the upper die 20 and the lower die 40 to obtain the finished product of the cage. Since six outer spokes 11 are bent at the same time, the sheet 10 is subjected to a large punching force, and is prone to warping and deformation, resulting in reduced cage accuracy, so it is necessary to clamp the sheet 10 with screws 50 in step 3.

[0050] Example 2. Figure 5 As shown, the mold includes an upper mold 20, a middle mold 30 and a lower mold 40;

[0051] The lower end of the upper die 20 contracts inwardly to form a journal 21 , and positioning grooves 23 are provided on both sides of the lower end of the journal 21 .

[0052] The upper die 20 is a tubular structure, the inner diameter of the middle die 30 matches the outer diameter of the journal 21, the length of the middle die 30 is greater than the length of the journal 21, an annular avoidance groove 31 is provided at the inner hole at the upper end of the middle die 30, and the outer diameter of the middle die 30 is greater than the outer diameter of the upper die 20;

[0053] The lower die 40 is a tubular structure, the inner diameter of the lower die 40 matches the outer diameter of the middle die 30 , and the length of the lower die 40 exceeds the length of the middle die 30 .

[0054] The lower end of the middle mold 30 is inserted into the upper end of the lower mold 40, the lower ends of the middle mold 30 and the lower ends of the lower mold 40 are both closed, a compression spring 60 connected to the lower mold 40 is provided at the bottom of the middle mold 30, and a vertical guide hole 41 is provided on the outer side wall of the lower mold 40, and a guide pin 32 fixed to the side wall of the middle mold 30 is provided in the guide hole 41. Under the pressure of the compression spring 60, the guide pin 32 is located at the upper end of the guide hole 41, and the guide pin 32 prevents the middle mold 30 from coming out of the lower mold 40.

[0055] Method of use of Example 2: Figure 5 As shown,

[0056] Step 1: Sleeve the sheet plate 10 onto the journal 21 of the upper mold 20, and the inner spokes enter the positioning grooves 23, so that the sheet plate 10 is limited in the horizontal direction and does not rotate.

[0057] Step 2: insert the journal 21 of the upper die 20 into the inner hole of the middle die 30 .

[0058] Step 3: Put the assembled mold on the press, and the press presses the upper mold 20 downward, the upper mold 20 descends, and the inner spokes 12 bend downward into the avoidance groove 31. Since only two inner spokes 12 are bent, the punching force on the sheet 10 is small, and it will not warp and deform, and the sheet 10 does not need to be pressed and fixed.

[0059] Here, the compression spring 60 needs to be selected well. The preload force of the compression spring 60 should be greater than the pressure acting on the compression spring 63 when the two inner spokes 12 are bent, that is, during the bending process of the inner spokes 12, the height of the middle mold 30 remains unchanged.

[0060] Until the upper mold 20 continues to descend until it contacts the sheet 10, the sheet 10 is pressed between the upper mold 20 and the middle mold 30. After the middle mold 30 continues to descend, the outer spoke 11 is bent upward by the lower mold 40 and enters the gap between the upper mold 20 and the lower mold 40 to obtain a finished retainer.

[0061] Compared with Example 1 and Example 2: Example 1 has a simpler structure, lower cost and production cycle, but the efficiency of processing the cage is relatively low, and it is suitable for cages with a production batch of less than 100. The cost and production cycle of Example 2 are slightly increased, but the increase is not large, but the efficiency of processing the cage is significantly improved, and it is suitable for cages with a production batch of 100-500. When the cage batch exceeds 1000, it is more appropriate to produce the cage with a special mold.

[0062] In the description of the embodiments, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation.

Claims

1. A die for bending and forming a special-shaped thin-walled part, the special-shaped thin-walled part comprising an annular plate (10), the outer side of the plate (10) being provided with a plurality of outer spokes (11) evenly distributed in the circumferential direction, and the inner side of the plate (10) being provided with two inner spokes (12) symmetrically distributed about the axis of the plate (10), characterized in that: The mold comprises an upper mold (20), a middle mold (30) and a lower mold (40); The lower end of the upper die (20) contracts inward to form a journal (21), and positioning grooves (23) are provided on both sides of the lower end of the journal (21); The upper die (20) is a tubular structure, the inner diameter of the middle die (30) matches the outer diameter of the shaft neck (21), the length of the middle die (30) is greater than the length of the shaft neck (21), an annular avoidance groove (31) is provided at the inner hole at the upper end of the middle die (30), and the outer diameter of the middle die (30) is greater than the outer diameter of the upper die (20); The lower die (40) is a tubular structure, the inner diameter of the lower die (40) matches the outer diameter of the middle die (30), and the length of the lower die (40) exceeds the length of the middle die (30).

2. The mold for bending and forming special-shaped thin-walled parts according to claim 1 is characterized in that: The mold further comprises a screw (50), the upper mold (20) is a tubular structure, and the inner side of the shaft neck (21) is provided with an internal thread (22) matching with the screw (50).

3. The die for bending and forming special-shaped thin-walled parts according to claim 2, characterized in that: The journal (21) matches the inner hole of the plate (10), the outer diameter of the upper die (20) is larger than the inner diameter of the plate (10), the difference between the inner hole diameter of the lower die (40) and the outer diameter of the upper die (20) is equal to the thickness of the outer spoke (11), the difference between the diameter of the avoidance groove (31) and the outer diameter of the journal (21) is equal to the thickness of the inner spoke (12), and the width of the positioning groove (23) matches the width of the inner spoke (12).

4. The die for bending and forming special-shaped thin-walled parts according to claim 3, characterized in that: The sum of the depth of the avoidance groove (31) and the thickness of the plate (10) is less than the length of the journal (21).

5. The die for bending and forming special-shaped thin-walled parts according to claim 4, characterized in that: The screw (50) comprises a screw rod (51) matched with the internal thread (22), a head (52) is provided at the lower end of the screw rod (51), and the sum of the thickness of the head (52), the length of the middle mold (30), the thickness of the sheet (10), and the bending length of the outer spoke (11) is less than the length of the lower mold (40).

6. The die for bending and forming special-shaped thin-walled parts according to claim 5, characterized in that: The depth of the avoidance groove (31) is greater than the bending length of the inner spoke (12).

7. The die for bending and forming special-shaped thin-walled parts according to claim 1, characterized in that: The lower end of the middle mold (30) is inserted into the upper end of the lower mold (40), the lower ends of the middle mold (30) and the lower ends of the lower mold (40) are both closed, a compression spring (60) connected to the lower mold (40) is provided at the bottom of the middle mold (30), and a vertical guide hole (41) is provided on the outer side wall of the lower mold (40), and a guide pin (32) fixed to the side wall of the middle mold (30) is provided in the guide hole (41).

8. The method for using the mold for bending and forming special-shaped thin-walled parts according to claim 6, characterized in that: The following steps are included: a. Put the plate (10) on the journal (21) of the upper die (20) and make the inner spoke 12 enter the positioning groove (23). b. The middle die (30) is put onto the shaft neck (21) of the upper die (20) to form a first assembly, and the first assembly is placed on a press for stamping. c. Assemble the screws (50) to the upper mold (20) so that the sheet (10) is pressed between the upper mold (20) and the middle mold (30) to form a second assembly. d. The lower die 40 is placed on the middle die (30) to form a third assembly, and the third assembly is placed on a press for stamping to obtain a finished product.

9. The method for using the mold for bending and forming special-shaped thin-walled parts according to claim 7, characterized in that: It includes the following steps: e. Put the plate (10) on the journal (21) of the upper mold (20), and make the inner spoke 12 enter the positioning groove (23). f. Insert the journal (21) of the upper mold (20) into the inner hole of the middle mold (30) to obtain an assembled mold. g. Place the assembled mold on a press for stamping to obtain the finished product.

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