Straightening device and method for hexagonal high-temperature alloy bar

Abstract

The invention discloses a straightening device and method for a hexagonal high-temperature alloy bar, the device comprises a feeding roller 1, a support 2, a hub 3, a plurality of dies 4 and a discharging roller 6, the hub 3 is mounted on the support 2 and is driven by a hub driving motor 7 to rotate through a belt 5, the dies 4 and the discharging roller 6 are arranged in the hub 3, and each die 4 is composed of an outer ring 41, a plurality of drum-shaped rollers 42 and an inner die 43. And a plurality of drum-shaped rollers 42 are uniformly distributed between the outer ring 41 and the inner mold 43. 360-degree all-directional straightening of the hexagonal bar is achieved, and accurate straightening is achieved. In addition, only sliding friction for advancing of the bar exists between the die and the bar in the method, the rotating direction is relatively static and free of friction, abrasion of the die and generation of heat are greatly reduced, the feeding speed of the hexagonal high-temperature alloy bar material is optimized, and the straightening effect is optimal. And meanwhile, through the design of the die, sliding friction is eliminated, heat productivity is reduced, and the service life of the die is prolonged.

Description

Technical Field

[0001] The present invention belongs to the field of new equipment and new material manufacturing, and particularly relates to a straightening device and method for hexagonal high-temperature alloy bars. Background Art

[0002] Cold-drawn high-temperature alloy bars are used as raw materials for fasteners in aerospace, nuclear power, and other fields. To achieve precise dimensions, higher strength, and finer grains to specific specifications, one or more cold-drawing cycles are required. This process generates significant residual internal stress within the bar. This uneven residual stress can cause the bar to bend, requiring straightening before further processing. Furthermore, after heat treatment, the bar may also exhibit some bends, requiring straightening.

[0003] There are two methods for straightening bars: repeated bending and straightening. The repeated bending straightening method straightens the material repeatedly in a specific direction and is suitable for straightening bars with large bending deformations. Rotary bending straightening methods are divided into rotating hub straightening and skew roller straightening. In the former, the bar does not rotate, while the straightening tool and die rotate around the bar axis. In the latter, the bar rotates, meaning the skew rollers rotate around the bar axis, achieving repeated straightening.

[0004] For round bars, straightening technology and related equipment are relatively mature. Typically, repeated bending straightening equipment, such as cantilever parallel roller straighteners, is used for primary straightening. Rotary bending straightening equipment is used for precision straightening. This is because rotary straightening is a comprehensive straightening method that is particularly effective for rotatable workpieces. Examples of rotary bending straightening equipment include multi-bevel roller straighteners, dual-curved roller straighteners, and rotary hub straighteners.

[0005] Hexagonal bars cannot be directly straightened using rotary straightening due to their hexagonal cross-section. Therefore, repeated bending straightening methods, such as cantilevered parallel roller straighteners, can only bend and straighten in three directions, as described in patent CN213671195U, "A Hexagonal Bar Straightener." These straightening methods cannot fully straighten the bars and cannot achieve precise straightening. If precise straightening is required, repeated straightening is required, requiring high operator experience and instability. Summary of the Invention

[0006] In order to overcome the deficiencies in the prior art, the purpose of the present invention is to develop a device and method suitable for straightening high-temperature alloy hexagonal bars. The specific technical solution is as follows: A straightening device for hexagonal high-temperature alloy bars includes a feed roller 1, a bracket 2, a hub 3, the hub 3 is installed on the bracket 2 and is driven to rotate by a hub drive motor 7 through a belt 5, multiple molds 4 and a discharge roller 6 are arranged inside the hub 3, wherein the mold 4 consists of an outer ring 41, multiple drum rollers 42 and an inner mold 43, and multiple drum rollers 42 are evenly distributed between the outer ring 41 and the inner mold 43.

[0007] The number of the molds 4 is an even number, preferably 6-12. The first and last molds are installed on the theoretical center line of the hexagonal high-temperature alloy rod, and the other molds are symmetrically staggered up and down. The eccentricity values ​​of the other molds except the first and last molds are set to ± (1-5.5) mm. Specifically, the number of the other molds except the first and last molds is 6 in one embodiment of the present invention, and the eccentricity values ​​of these 6 molds from the feeding direction to the discharging direction are set as follows: the absolute values ​​of the eccentricity values ​​of the first and second molds are the same, but one is upward and the other is downward; the absolute values ​​of the eccentricity values ​​of the third and fourth molds are the same and are smaller than the absolute values ​​of the eccentricity values ​​of the first and second molds, and one is upward and the other is downward, and at the same time, the eccentricity directions of the first mold and the third mold are consistent, and the eccentricity directions of the second mold and the fourth mold are consistent; the absolute values ​​of the eccentricity values ​​of the fifth and sixth molds are the same and are smaller than the absolute values ​​of the eccentricity values ​​of the third and fourth molds, and one is upward and the other is downward, and at the same time, the eccentricity directions of the third mold and the fifth mold are consistent, and the eccentricity directions of the fourth mold and the sixth mold are consistent. The eccentricity gradually decreases from the incoming wire direction. Initially, a large eccentricity is required to produce a large bending force on the bar, unifying the bar's bending direction. A smaller bending force is then used to unify the residual bending force, straighten the bar, and ultimately eliminate any residual bending force. The eccentricity setting should be determined based on the bar's material characteristics and size, preferably within a range of ±(1-5.5) mm.

[0008] Because the combined effects of the bar's forward speed and the hub's rotational speed create a spiral bending trajectory for the dies, the present invention sets the distance between adjacent dies to an integer multiple of half the hexagonal superalloy bar's lead, i.e., the distance between adjacent dies is L = N × 0.5VT, where N is a non-zero integer, preferably 4-30, more preferably 8-30; V refers to the hexagonal superalloy bar's feed speed; and T refers to the time required for the hub 3 to complete one rotation. This ensures that the dies can achieve uniform bending direction through large deformation in the first half of a rotation, then achieve uniform residual bending through large bending for at least one half of a rotation, perform small deformation straightening through bending for at least one half of a rotation, and finally eliminate individual residual bending values ​​through small deformation bending for at least one half of a rotation, ultimately achieving the straightening objective.

[0009] Preferably, T refers to the time required for the hub 3 to rotate one circle, which is 1 / 1300-1 / 800 min.

[0010] The inner die 43 has a hexagonal hole at its center, sized and shaped to match the cross-section of the hexagonal superalloy rod. It has 40-50° chamfers 44 on either side, which transition into the circular arc of the hexagonal hole. Preferably, the gap between the inner die 43 and the hexagonal superalloy rod is 0.5-1 mm.

[0011] The radius of the drum roller 42 is 1-3 mm smaller than the radius of the arc groove between the inner mold 43 and the outer circle 41 , so that the inner mold 43 can swing within the range of 1-3 degrees.

[0012] A straightening method for hexagonal high-temperature alloy bars, specifically as follows: the hexagonal high-temperature alloy bars are fed into a feed roller 1, the hexagonal high-temperature alloy bars are pushed into a wheel hub 3 under the clamping of the feed roller 1 and pass through each mold 4 in sequence, the mold 4 rotates with the wheel hub 3 and then rotates and repeatedly bends and straightens the hexagonal high-temperature alloy bars, and the hexagonal high-temperature alloy bars advance to a receiving roller 6 and are pulled out by it.

[0013] The feed speed of the hexagonal superalloy bars needs to be set within a reasonable range. If the speed is too high, the hub speed must be increased, which generates greater centrifugal force, requiring structural changes and strengthening of the equipment, increasing the requirements for the civil engineering foundation, or increasing the number of molds, increasing the complexity of the equipment structure and making operation more complicated. Taking these factors into consideration, the feed speed is set at 10-15 m / min.

[0014] The present invention feeds the hexagonal bars to be straightened from a feed roller 1 into a rotating hub 3, passes them through a die 4 one by one, and then is drawn out by a rear feed roller 6. During this process, the rotating hub 3 drives the die 4 to rotate about the centerline of the bars, repeatedly rotating and bending the bars to achieve straightening. This allows for 360° straightening of the hexagonal bars, achieving precise straightening. Furthermore, in this method, the only friction between the die and the bars is sliding due to the bars' forward movement; the rotational direction is relatively static and frictionless, significantly reducing die wear and heat generation. This optimizes the feed rate of the hexagonal high-temperature alloy bars and achieves optimal straightening results. Furthermore, the die design eliminates sliding friction, reduces heat generation, and extends the die's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the hexagonal high-temperature alloy bar straightening device of the present invention; Figure 2 Schematic diagram of the structure of the mold of the present invention; Figure 3 It is a cross-sectional view of the mold of the present invention.

[0016] Among them: 1-feed roller, 2-bracket, 3-hub, 4-mold, 5-belt, 6-discharge roller, 7-hub drive motor, 41-outer ring, 42-drum roller, 43-inner mold, 44-chamfer. DETAILED DESCRIPTION Example 1

[0017] like Figure 1 As shown, a straightening device for hexagonal high-temperature alloy bars includes a feed roller 1, a bracket 2, a hub 3, the hub 3 is installed on the bracket 2 and is driven to rotate by a hub drive motor 7 through a belt 5, multiple molds 4 and a discharge roller 6 are arranged inside the hub 3, wherein the mold 4 consists of an outer ring 41, multiple drum rollers 42 and an inner mold 43, and multiple drum rollers 42 are evenly distributed between the outer ring 41 and the inner mold 43.

[0018] There are six dies 4, with the first and last dies mounted on the theoretical centerline of the hexagonal superalloy bar, and the remaining dies arranged in a staggered arrangement. One method for mounting the dies 4 is to machine holes in the hub 3 to accommodate the dies 4, insert the dies into the holes, and securely secure them. The distance between adjacent dies is set to 110 mm. The eccentricity values ​​of the remaining dies, other than the six, are set to 0 mm, +5.5 mm, -5.5 mm, +3.2 mm, -3.2 mm, +1 mm, -1 mm, and 0 mm, respectively, from the feed end to the discharge end.

[0019] The center of the inner die 43 is a hexagonal hole whose size and shape match the cross section of the hexagonal high-temperature alloy rod. Chamfers 44 of 40-50 degrees are provided on both sides of the inner die 43 , and the chamfers 44 transition to the arc of the hexagonal hole.

[0020] The radius of the drum roller 42 is 1-3 mm smaller than the radius of the arc groove between the inner mold 43 and the outer circle 41, so that the inner mold 43 can swing within the range of 1-3 degrees. Example 2

[0021] One end of the hexagonal high-temperature alloy rod to be straightened is fed into the feed roller of the device as described in Example 1. The hexagonal high-temperature alloy rod is pushed into the wheel hub 3 under the clamping of the feed roller 1 and passes through each mold 4 in turn. The mold 4 rotates with the wheel hub 3 and then rotates and repeatedly bends and straightens the hexagonal high-temperature alloy rod. The hexagonal high-temperature alloy rod moves forward to the receiving roller 6 and is pulled out by it.

[0022] The feeding speed of the hexagonal superalloy bar was set at 15 m / min, and the rotation speed of the hub 3 was set at 1100 rpm. The straightness test result of the hexagonal superalloy bar before straightening was 15 mm / m. The straightness test result of the hexagonal superalloy bar after straightening was no higher than 0.9 mm / m. Example 3

[0023] A straightening device for hexagonal high-temperature alloy bars includes a feed roller 1, a bracket 2, a hub 3, the hub 3 is installed on the bracket 2 and is driven to rotate by a hub drive motor 7 through a belt 5, multiple molds 4 and a discharge roller 6 are arranged inside the hub 3, wherein the mold 4 consists of an outer ring 41, multiple drum rollers 42 and an inner mold 43, and multiple drum rollers 42 are evenly distributed between the outer ring 41 and the inner mold 43.

[0024] The number of dies 4 is 12. The first and last dies are mounted on the theoretical centerline of the hexagonal superalloy bar, and the other dies are staggered vertically. The distance between adjacent dies is 75 mm, which is eight times half the lead of the hexagonal superalloy bar. The eccentricity values ​​of the 12 dies are set to 0 mm, +5.5 mm, -5.5 mm, +4.3 mm, -4.3 mm, +3.2 mm, -3.2 mm, +2.1 mm, -2.1 mm, +1 mm, -1 mm, and 0 mm, respectively, from the feed end to the discharge end.

[0025] The center of the inner die 43 is a hexagonal hole whose size and shape match the cross section of the hexagonal high-temperature alloy rod. Chamfers 44 of 40-50 degrees are provided on both sides of the inner die 43 , and the chamfers 44 transition to the arc of the hexagonal hole.

[0026] The radius of the drum roller 42 is 1-3 mm smaller than the radius of the arc groove between the inner mold 43 and the outer circle 41, so that the inner mold 43 can swing within the range of 1-3 degrees.

[0027] One end of the hexagonal high-temperature alloy rod to be straightened is fed into the feed roller of the above-mentioned device. The hexagonal high-temperature alloy rod is pushed into the wheel hub 3 under the clamping of the feed roller 1 and passes through each mold 4 in turn. The mold 4 rotates with the wheel hub 3 and then repeatedly bends and straightens the hexagonal high-temperature alloy rod three times. The hexagonal high-temperature alloy rod moves forward to the receiving roller 6 and is pulled out by it.

[0028] The feeding speed of the hexagonal high-temperature alloy rod is set to 10 m / min, and the rotation speed of the hub 3 is set to 850 rpm. The straightness test result of the hexagonal high-temperature alloy rod before straightening is 15 mm / m. The straightness test result of the hexagonal high-temperature alloy rod after straightening is 0.8 mm / m. Example 4

[0029] A straightening device for hexagonal high-temperature alloy bars includes a feed roller 1, a bracket 2, a hub 3, the hub 3 is installed on the bracket 2 and is driven to rotate by a hub drive motor 7 through a belt 5, multiple molds 4 and a discharge roller 6 are arranged inside the hub 3, wherein the mold 4 consists of an outer ring 41, multiple drum rollers 42 and an inner mold 43, and multiple drum rollers 42 are evenly distributed between the outer ring 41 and the inner mold 43.

[0030] The dies 4 are eight in number, with the first and last dies mounted on the theoretical centerline of the hexagonal superalloy bar. The other dies are staggered vertically, with the distance between adjacent dies being 173 mm, 30 times half the lead of the hexagonal superalloy bar. The eccentricity values ​​of the twelve dies are set to 0 mm, +5.2 mm, -5.2 mm, +3 mm, -3 mm, +1.5 mm, -1.5 mm, and 0 mm, respectively, from the feed end to the discharge end.

[0031] The center of the inner die 43 is a hexagonal hole whose size and shape match the cross section of the hexagonal high-temperature alloy rod. Chamfers 44 of 40-50 degrees are provided on both sides of the inner die 43 , and the chamfers 44 transition to the arc of the hexagonal hole.

[0032] The radius of the drum roller 42 is 1-3 mm smaller than the radius of the arc groove between the inner mold 43 and the outer circle 41, so that the inner mold 43 can swing within the range of 1-3 degrees.

[0033] One end of the hexagonal high-temperature alloy rod to be straightened is fed into the feed roller of the above-mentioned device. The hexagonal high-temperature alloy rod is pushed into the wheel hub 3 under the clamping of the feed roller 1 and passes through each mold 4 in turn. The mold 4 rotates with the wheel hub 3 and then repeatedly bends and straightens the hexagonal high-temperature alloy rod three times. The hexagonal high-temperature alloy rod moves forward to the receiving roller 6 and is pulled out by it.

[0034] The feeding speed of the hexagonal superalloy bar was set at 15 m / min, and the rotation speed of the hub 3 was set at 1300 rpm. The straightness test results of the hexagonal superalloy bar before straightening were: 15 mm / m. The straightness test results of the hexagonal superalloy bar after straightening were: 0.95 mm / m.

Claims

1. A straightening device for hexagonal high-temperature alloy bars, characterized in that The invention comprises a feeding roller (1), a bracket (2), a wheel hub (3) and a discharging roller (6), wherein the wheel hub (3) is mounted on the bracket (2) and driven to rotate by a wheel hub driving motor (7) via a belt (5), and a plurality of dies (4) are arranged inside the wheel hub (3), wherein the dies (4) are composed of an outer ring (41), a plurality of drum-shaped rollers (42) and an inner die (43), and the plurality of drum-shaped rollers (42) are evenly distributed between the outer ring (41) and the inner die (43), and the number of the dies (4) is 6-12, the first and last dies are mounted on the theoretical center line of the hexagonal high-temperature alloy bar, and the other dies are symmetrically arranged in an alternating manner up and down, and the distance between adjacent dies is L=N×0.5VT, wherein N is an integer not equal to 0, V refers to the feeding speed of the hexagonal high-temperature alloy bar, and T refers to the time required for the wheel hub (3) to rotate one circle.

2. The straightening device for hexagonal high-temperature alloy bars according to claim 1, characterized in that The center of the inner die (43) is a hexagonal hole whose size and shape match the cross section of the hexagonal high-temperature alloy rod, and chamfers (44) of 40-50° are provided on both sides of the inner die, and the chamfers (44) transition to the hexagonal hole in an arc.

3. The straightening device for hexagonal high-temperature alloy bars according to claim 2, characterized in that The radius of the drum-shaped roller (42) is 1-3 mm smaller than the radius of the arc groove between the inner mold (43) and the outer circle (41).

4. The straightening device for hexagonal high-temperature alloy bars according to claim 1, characterized in that The eccentricity values ​​of the molds other than the first and last molds are set to ± (1-5.5) mm.

5. The straightening device for hexagonal high-temperature alloy bars according to claim 1, characterized in that The N is 4-30; V1 is 10-15 m / min; and T is 1 / 1300-1 / 800 min.

6. A straightening method for hexagonal high-temperature alloy bars, characterized in that The specific method is as follows: a hexagonal high-temperature alloy rod is fed into a feeding roller (1); the hexagonal high-temperature alloy rod is clamped by the feeding roller (1) and pushed into a wheel hub (3) and passes through each mold (4) in sequence; the mold (4) rotates with the wheel hub (3) and then rotates and repeatedly bends and straightens the hexagonal high-temperature alloy rod; the hexagonal high-temperature alloy rod is advanced to a receiving roller (6) and is pulled out by the receiving roller.

7. The straightening method for hexagonal high-temperature alloy bars according to claim 6, characterized in that The feeding speed of the hexagonal high-temperature alloy rod is set to 10-15m / min.

8. The straightening method for hexagonal high-temperature alloy bars according to claim 6, characterized in that The time required for the wheel hub (3) to rotate once is 1 / 1300-1 / 800 min.

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