Chain ring bending die set based on annular chain machining

Abstract

The utility model relates to a chain ring bending die set for processing based on an annular chain, which comprises two pre-bending core dies which are longitudinally and oppositely arranged, the pre-bending core die positioned at the upper part is a fixed die, and the pre-bending core die positioned at the lower part is a movable die; wherein the middle part of the mold forming end surface of the pre-bending core mold is integrally connected with an elliptical mold forming boss, and the peripheral surface of the mold forming boss is an arc step surface; a positioning clamping groove is formed after the die forming bosses of the two pre-bending core dies are in butt joint; the two bending molds are transversely and symmetrically arranged on the two sides of the positioning clamping groove, L-shaped bending arc grooves are formed in the inner sides of the ends of the bending molds in a penetrating mode, limiting grooves are vertically formed in the corners of the bending arc grooves from top to bottom, dumbbell-shaped balls are arranged in the limiting grooves in an axial clearance sleeving mode, and the radian of the inner arc surfaces of the balls is the same as that of the inner arc surfaces of the bending arc grooves. According to the utility model, the surface galling caused by traditional hard scraping is effectively avoided, the smoothness of the bent surface of the chain ring is improved, and the requirements of subsequent polishing procedures are reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to annular chain processing technical field, especially involves the chain ring bending complete mould based on annular chain processing. BACKGROUND

[0002] Annular chain processing flow is generally cutting carbon steel or stainless steel wire rod to fixed length, bending two ends to form ring and close interface through cold bending, reinforcing connecting place through resistance butt welding or argon arc welding, improving material hardness and toughness through quenching and tempering, enhancing rustproof performance through surface zinc plating or polishing, finally detecting chain ring size and tensile strength to ensure to meet industrial standard.

[0003] The above-mentioned cold bending step is divided into one-time pre-bending forming and two-time closed forming, wherein the one-time pre-bending forming is to bend two ends of the fixed-length wire rod inward to form a pre-bending blank by using a die.

[0004] The die used in the one-time pre-bending forming generally comprises two pre-bending core dies longitudinally arranged opposite to each other and two bending dies horizontally and symmetrically arranged on both sides of the positioning clamping groove formed after the two pre-bending core dies are butted. TECHNICAL SOLUTION

[0005] The utility model provides a chain ring bending complete mould based on annular chain processing in view of the deficiency of the prior art, and the specific technical scheme is as follows:

[0006] The utility model provides a chain ring bending complete mould based on annular chain processing, which is used for bending two ends of the fixed-length wire rod inward to form a pre-bending blank of the chain ring, and the complete mould comprises

[0007] Two pre-bending core dies are longitudinally arranged opposite to each other, and the pre-bending core die at the upper part is a fixed die, and the pre-bending core die at the lower part is a movable die.

[0008] Two bending dies are horizontally and symmetrically arranged on both sides of the positioning clamping groove, and an L-shaped bending arc groove is formed in the inner side of the end of the bending die, a limiting groove is vertically formed from top to bottom at the corner of the bending arc groove, a dumbbell-shaped ball bearing is axially and gapingly sleeved in the limiting groove, and the inner arc surface of the ball bearing and the inner arc surface of the bending arc groove have the same curvature.

[0009] As a preferred technical scheme of the utility model, the through hole is axially and centrally formed in the inner bottom surface of the limiting groove.

[0010] As a preferred technical scheme of the utility model, the height of the top surface of the ball is less than or equal to the height of the top opening of the limiting groove.

[0011] As a preferred technical scheme of the utility model, the gap at the top opening of the limiting groove is attached with an axial limiting structure composed of a screw and a steel sheet.

[0012] As a preferred technical scheme of the utility model, the pre-bending core die is externally tangent with a circular arc curved surface along the circular arc step surface of the die forming boss, and the positioning clamping groove formed by the die forming bosses of the two pre-bending core dies with the circular arc curved surface has a smaller diameter than the positioning clamping groove formed by the die forming bosses of the two pre-bending core dies without the circular arc curved surface.

[0013] As a preferred technical scheme of the utility model, the die forming boss of the pre-bending core die is inwardly concave with a circular arc-shaped back.

[0014] The utility model has the advantages of:

[0015] 1. The axial gap sleeve of the ball is arranged at the corner of the bending arc groove, the traditional bending die and the sliding friction of the wire rod are changed into rolling friction, the inner arc surface of the ball is matched with the bending arc groove in design, the contact surface pressure is uniformly distributed when the wire rod is bent, the structure effectively avoids the surface fuzz caused by traditional hard scraping, improves the smoothness of the bending surface of the chain ring, and reduces the requirement of the subsequent polishing process.

[0016] 2. The axial gap sleeve of the ball in the limiting groove allows the ball to produce self-rotation displacement during the bending process. When the end of the wire rod is deformed under pressure, the ball can adaptively adjust the contact angle along the material flow direction, avoid the material surface micro-cracks caused by local stress concentration, and ensure the guiding effect of the bending arc groove on the wire rod. The ball can also make a certain degree of self-adaptive axial displacement adjustment according to the position of the wire rod after being pressed tightly to adapt to the parallelism after the wire rod is pressed tightly.

[0017] 3. The upper and lower pre-bending core dies are designed in a split type of fixed die and movable die, cooperate with the ball auxiliary bending structure, so that the wire rod is always in a controlled deformation state during the dynamic bending process. The positioning clamping groove formed by the butt joint of the die forming boss and the two side ball bending modules constitute a three-dimensional constraint system, effectively inhibit the wire rod rebound, and improve the size consistency of the pre-bending blank. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The overall working demonstration diagram of the utility model is shown.

[0019] Figure 2 The structure schematic view of the ball top surface lower than the limit groove top opening in the curved die is shown;

[0020] Figure 3 The structure schematic view of the ball top surface flush with the limit groove top opening in the curved die is shown;

[0021] Figure 4 The structure schematic view of the curved die without assembling the ball is shown;

[0022] Figure 5 The structure schematic view of the ball in the curved die is shown;

[0023] Figure 6 The structure schematic view of the pre-bending core die in the embodiment one of the utility model is shown;

[0024] Figure 7 The structure schematic view of the two pre-bending core dies after splicing in the embodiment one of the utility model is shown;

[0025] Figure 8 The structure schematic view of the pre-bending blank carding into the positioning card slot in the embodiment one of the utility model is shown;

[0026] Figure 9 The structure schematic view of the pre-bending core die in the embodiment two of the utility model is shown;

[0027] Figure 10 The structure schematic view of the two pre-bending core dies after splicing in the embodiment two of the utility model is shown;

[0028] Figure 11 The structure schematic view of the pre-bending blank carding into the positioning card slot in the embodiment two of the utility model is shown.

[0029] As shown in the figure: 1, curved die; 11, bending arc groove; 12, limit groove; 121, through hole; 13, ball; 2, pre-bending core die; 21, die boss; 211, arc step surface; 212, bend back; 213, arc curved surface; 3, pre-bending blank; 4, positioning card slot; 5, bottom diameter. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following is combined with the embodiment, and the utility model is further described in detail. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0031] Embodiment one

[0032] To solve the technical problems in the background art, the following chain ring bending complete mold for processing ring chain is given:

[0033] In combination Figures 1-8 As shown in the chain ring bending complete mold for processing ring chain, the complete mold is used for bending the two ends of the fixed-length wire for chain ring inward to form a pre-bending blank 3 of the chain ring, and the complete mold comprises

[0034] Two pre-bending core molds 2 are longitudinally arranged opposite to each other, and the pre-bending core mold 2 at the upper side is a fixed mold, and the pre-bending core mold 2 at the lower side is a movable mold; wherein the middle part of the molding end face of the pre-bending core mold 2 is integrally connected with an oval molding boss 21, and the outer peripheral surface of the molding boss 21 is provided as a circular arc stepped surface 211; the molding bosses 21 of the two pre-bending core molds 2 are butted to form a positioning clamping groove 4;

[0035] Two bending molds 1 are horizontally arranged symmetrically on both sides of the positioning clamping groove 4, and the inner side of the end portion of the bending mold 1 is provided with an L-shaped bending arc groove 11, and a limiting groove 12 is vertically provided from top to bottom at the corner of the bending arc groove 11, and a dumbbell-shaped ball 13 is axially gap-sleeved in the limiting groove 12, and the inner arc surface of the ball 13 and the inner arc surface of the bending arc groove 11 have the same curvature.

[0036] By adopting the above technical scheme, the complete mold converts the sliding friction between the traditional bending mold 1 and the wire into rolling friction by gap-sleeving the dumbbell-shaped ball 13 at the corner of the bending arc groove 11. The inner arc surface of the ball 13 and the bending arc groove 11 are designed to match the curvature, so that the contact surface pressure is uniformly distributed when the wire is bent. This structure effectively avoids the surface fuzzing caused by traditional hard scraping, improves the smoothness of the chain ring bending surface, and reduces the subsequent polishing process requirements.

[0037] The axial gap sleeve of the ball 13 in the limiting groove 12 of the complete mold allows the ball 13 to produce self-rotation displacement during the bending process. When the end portion of the wire is deformed under pressure, the ball 13 can adaptively adjust the contact angle according to the material flow direction, avoid local stress concentration caused by material surface micro-cracks, and ensure the guiding effect of the bending arc groove 11 on the wire. The ball 13 can also make a certain degree of self-adaptive axial displacement adjustment in the limiting groove 12 according to the position of the wire after being tightly pressed, to adapt to the parallelism of the wire after being tightly pressed.

[0038] The upper and lower pre-bending core molds 2 of the complete mold adopt a split design of fixed mold and movable mold, which cooperates with the ball 13 auxiliary bending structure to keep the wire in a controlled deformation state during the dynamic bending process. The positioning clamping groove 4 formed by the butt joint of the molding bosses 21 and the two-side ball 13 bending modules constitute a three-dimensional constraint system, which effectively suppresses the wire springback and improves the size consistency of the pre-bending blank 3.

[0039] Preferably, from the two slot ends of the L-shaped bending arc groove 11, the inner arc surface height of the ball 13 is slightly lower than the inner arc surface height of the bending arc groove 11 or the two heights are flush, which facilitates better rolling and bending of the wire.

[0040] As shown in Figure 1 and Figure 6 , the back of the molding boss 21 of the pre-bending core mold 2 is inwardly recessed with a circular-arc-shaped back bending 212.

[0041] By adopting the above technical scheme, the back bending 212 will form a circular-arc-shaped bending segment in the middle of the wire after the top rod abuts against the wire, which can play a positioning role, so that the wire does not swing during the pushing and bending process of the bending mold 1; in the subsequent secondary closed forming process, the circular-arc-shaped bending segment on the pre-bending blank 3 will provide a deformation amount, which will gradually flatten after the chain ring is formed and closed, so that the formed chain ring looks better.

[0042] As shown in Figure 4 , an axial through hole 121 is provided in the middle of the inner bottom surface of the limiting groove 12.

[0043] By adopting the above technical scheme, after the ball 13 is stuck in the limiting groove 12, a thimble can be used to lift the ball 13 upward from the through hole 121 to push out the stuck and deformed ball 13 from the limiting groove 12.

[0044] As shown in Figure 2 and Figure 3 , the top surface height of the ball 13 is less than or equal to the top opening height of the limiting groove 12.

[0045] By adopting the above technical scheme, the top surface height of the ball 13 does not exceed the top opening of the limiting groove 12, and in combination with the axial gap sleeve structure, the ball 13 can be slightly axially displaced in the limiting groove 12 when under pressure, while avoiding hard collision of the ball 13 with the edge of the limiting groove 12 due to the too high top surface. The ball 13 can freely roll in the deformation direction of the wire during the bending process, which not only reduces the surface fuzzing caused by sliding friction, but also prevents the ball 13 from moving axially out of the working position, ensuring that the rolling friction continues to be effective.

[0046] Preferably, the gap at the top opening of the limiting groove 12 is provided with an axial limiting structure composed of a screw and a steel sheet (not shown in the figure).

[0047] By adopting the technical scheme, the steel sheet fixed by the screw forms a controllable gap limiting structure at the top of the limiting groove 12, which allows the slight axial displacement of the ball 13 in the bending process due to the wire deformation force (to adapt to the material flow) and limits the excessive displacement of the ball 13 in the non-working direction. This design avoids the failure of the bending guide caused by the excessive displacement of the ball 1 out of the limiting groove 12, ensures that the ball 13 is always in the effective working area, and maintains the stability of the rolling friction.

[0048] The screw-connected steel sheet is detachable. When the ball 13 needs to be repaired or replaced, the steel sheet can be removed only by disassembling the screw, without damaging the overall structure of the limiting groove 12. In combination with the through hole 121 at the bottom of the limiting groove 12, the axial limiting structure further simplifies the ejection operation path of the ball 13, improving the mold maintenance efficiency. At the same time, the gap of the steel sheet can avoid secondary damage to the ball 13 or the limiting groove 12 during disassembly.

[0049] Embodiment two

[0050] In combination Figures 9-11 As shown in the above embodiment, the present embodiment further gives the following contents:

[0051] In the present embodiment, the pre-bending core mold 2 is provided with an arc curved surface 213 outside the arc step surface 211 of the molding boss 21, and the diameter of the positioning clamping groove 4 formed by the butt joint of the two pre-bending core molds 2 provided with the arc curved surface 213 is smaller than that of the positioning clamping groove 4 formed by the butt joint of the two pre-bending core molds 2 without the arc curved surface 213.

[0052] In the embodiment one, the positioning clamping groove 4 formed by the butt joint of the two pre-bending core molds 2 is provided with a bottom diameter 5 at the center of the bottom surface. The wire will be in close contact with the bottom diameter 5 during the bending process of the pre-bending blank 3, and finally a linear extrusion mark will be formed. This linear extrusion mark will produce cracks in the subsequent quenching process, which will have a great impact on the working pressure of the chain ring. In the pickling process of galvanizing, the acid liquid will also penetrate into the deep crack, causing over-corrosion: the metal at the edge of the crack is over-dissolved, the defect is enlarged; hydrogen embrittlement risk: hydrogen atoms in the acid penetrate into the crack area, reducing the toughness of the material; poor adhesion of the coating: it is difficult for the zinc layer to cover the inside of the crack, which is easy to peel off and leave the acidic medium, accelerating the internal rust. After galvanizing, the crack is covered, but the hidden danger still exists, which may cause sudden rupture during use.

[0053] By adopting the technical scheme, the pre-bending core die 2 is provided with the circular arc curved surface 213 outside the circular arc step surface 211 of the molding boss 21, and the diameter of the positioning clamping groove 4 of the improved pre-bending core die 2 is smaller than that of the traditional pre-bending core die 2, so that the positioning clamping groove 4 of the improved pre-bending core die 2 is formed in a trumpet-shaped structure, the wire under pressure is tightly pressed against the circular arc curved surface 213 and does not contact the bottom diameter 5 at the center of the bottom surface of the positioning clamping groove 4, so that linear extrusion marks are not formed, and the quality of the formed chain ring is improved.

[0054] The working principle and use process of the utility model are as follows:

[0055] In use, first, the fixed-length wire is placed between the upper and lower pre-bending core dies 2. The upper fixed die and the lower movable die are longitudinally butted through the molding boss 21, and the circular arc step surface 211 of the oval molding boss 21 forms the positioning clamping groove 4 with a suitable wire diameter. The rear top rod pushes the wire to tightly press and clamp into the positioning clamping groove 4, and at this time, the circular arc back 212 of the pre-bending core die 2 makes the middle part of the wire form an arc-shaped bending section, realizing bidirectional positioning and preventing the wire from swinging in subsequent bending.

[0056] After positioning, the two bending dies 1 symmetrically arranged transversely are synchronously moved to the wire end. The L-shaped bending arc groove 11 at the end of the bending die 1 gradually wraps the wire end, and the dumbbell-shaped ball 13 in the limiting groove 12 at the corner thereof begins to contact the wire. Since the top surface height of the ball 13 does not exceed the top opening of the limiting groove 12, and the axial limiting structure composed of a screw and a steel sheet restricts the axial displacement of the ball 13, the ball 13 can only slightly rotate or axially float in the limiting groove 12 when pressed, avoiding hard friction with the wire.

[0057] With the continuous advancement of the bending die 1, the ball 13 rolls in the limiting groove 12, and the inner arc surface thereof matches the curvature of the bending arc groove 11, so as to bend the wire end inward along the L-shaped trajectory. The rolling friction of the ball 13 replaces the traditional sliding friction, effectively eliminating surface fuzzing; at the same time, the trumpet-shaped positioning clamping groove 4 of the circular arc curved surface 213 in the improved pre-bending core die 2 makes the wire only contact the circular arc curved surface 213, avoiding linear extrusion marks at the bottom diameter 5, and ensuring that there is no stress concentration point in the bending process.

[0058] The above only describes preferred embodiments of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement and improvement made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A complete mold for bending a chain link for a ring chain based on machining, characterized in that: The complete mold is used for bending two ends of a fixed-length wire rod for a chain link inward to form a pre-bending blank (3) of the chain link, and comprises ​ Two pre-bending core molds (2) are longitudinally arranged oppositely, and the pre-bending core mold (2) at the upper side is a fixed mold, and the pre-bending core mold (2) at the lower side is a movable mold; wherein an elliptical molding boss (21) is integrally connected to the middle part of the molding end face of the pre-bending core mold (2), and the outer peripheral surface of the molding boss (21) is provided as a circular arc stepped surface (211); the molding bosses (21) of the two pre-bending core molds (2) are butted to form a positioning clamping groove (4); Two bending molds (1) are horizontally symmetrically arranged on both sides of the positioning clamping groove (4), and an L-shaped bending arc groove (11) is vertically and longitudinally arranged in the inner side of the end part of the bending mold (1), a limiting groove (12) is vertically arranged at the corner of the bending arc groove (11), a dumbbell-shaped ball (13) is axially and gapingly arranged in the limiting groove (12), and the inner arc surface of the ball (13) has the same curvature as the inner arc surface of the bending arc groove (11).

2. The complete mold set for bending the chain link for the ring chain based processing chain link according to claim 1, characterized in that: An axial through hole (121) is vertically and longitudinally arranged in the middle part of the inner bottom surface of the limiting groove (12).

3. The complete mold set for bending the chain link for the ring chain based processing chain link according to claim 1, characterized in that: The height of the top surface of the ball (13) is less than or equal to the height of the top opening of the limiting groove (12).

4. The complete mold for bending the chain link for the ring chain based processing according to claim 3, characterized in that: An axial limiting structure composed of a screw and a steel sheet is gapingly arranged at the top opening of the limiting groove (12).

5. The complete mold for bending the chain link for the ring chain based processing according to claim 1, wherein: The pre-bending core mold (2) is outwardly tangent to the circular arc stepped surface (211) of the molding boss (21) of the pre-bending core mold (2) along the circular arc curved surface (213), and the diameter of the positioning clamping groove (4) formed by the butt joint of the molding bosses (21) of the two pre-bending core molds (2) provided with the circular arc curved surface (213) is smaller than the diameter of the positioning clamping groove (4) formed by the butt joint of the molding bosses (21) of the two pre-bending core molds (2) without the circular arc curved surface (213).

6. The complete mold for bending the chain link for the endless chain based processing chain ring according to any one of claims 1 to 5, characterized in that: The back surface of the molding boss (21) of the pre-bending core mold (2) is inwardly concave to form a circular arc-shaped bent back (212).

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