High-precision straightening machine for shaft bars

Abstract

The invention relates to the technical field of bar straightening, in particular to a shaft bar high-precision straightening machine which comprises a lower pressing head, supporting heads and an end bearing head, the supporting heads are symmetrically arranged and form two lower supporting points, and auxiliary pressing heads are symmetrically arranged on the lower pressing head; side pressing heads are symmetrically arranged on the side, away from the lower pressing head, of each supporting head, synchronous association heads are arranged between the side pressing heads and the corresponding auxiliary pressing heads, and the symmetrically-arranged side pressing heads and the corresponding auxiliary pressing heads are matched to form side pulling units. In the process that the lower pressing head presses the bar downwards for straightening, the side pressing head automatically establishes a limiting connection relation with the auxiliary pressing head through the synchronous association head and forms the side pulling unit, and the side pulling unit automatically pulls the bar outwards from the outside of the lower supporting point in the process that the lower pressing head makes contact with the bar and presses the bar downwards. Elastic recovery after unloading is effectively reduced, the straightening effect is improved, the number of times of iterative circulation straightening in the same area is correspondingly reduced, the straightening time is shortened, and the straightening efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bar straightening, and particularly to a high-precision straightening machine for shaft-shaped bars. Background Art

[0002] As a key basic component in the field of mechanical manufacturing, shaft-shaped bars will inevitably undergo bending deformation during rolling, heat treatment, machining, and storage and transportation. This deformation will directly affect the quality of subsequent finish machining, assembly accuracy, and the overall performance and service life of the product.

[0003] The three-point bending straightening method, as a commonly used straightening method for shaft-shaped bars, mainly forms a span through two lower support points, and applies a load to the convex part of the bar bending by using a lower pressure head located above the middle of the span, so that the local area generates plastic bending deformation opposite to the original bending and exceeding the material yield limit, so as to make the bar tend to be straight after unloading by means of elastic recovery.

[0004] Existing high-precision straightening equipment generally integrates an online detection system (such as laser scanning and multi-probe contact measurement) and an actuator linkage to realize the automatic identification of the bending position and the precise positioning of the straightening head, which significantly improves the detection and positioning efficiency. However, in the actual straightening process, the expected plastic deformation generated by the downward pressure will be partially offset by the accompanying elastic deformation recovery (i.e., springback) during unloading. This springback amount is often considerable, resulting in the actual residual bending degree of the bar still being difficult to approach the high-precision requirements after a single straightening. In order to compensate for the springback amount and achieve the target straightness, the equipment needs to perform repeated operations of "detection - downward pressure straightening - re-detection" on the same bending part multiple times. Each iteration cycle significantly increases the straightening time of a single workpiece, restricting the improvement of the overall efficiency. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a high-precision straightening machine for shaft-shaped bars, including a lower pressure head, a support head, and an end bearing joint. The support heads are symmetrically arranged to form two lower support points, and the lower pressure head is arranged above the middle of the two lower support points. The support head moves synchronously along the axial direction of the bar as the lower pressure head moves downward; auxiliary pressure heads are symmetrically arranged on the lower pressure head, and the auxiliary pressure heads are located on both sides of the lower pressure head along the axial direction of the bar; side pressure heads are symmetrically arranged on one side of each support head away from the lower pressure head, and a synchronous connection head is arranged between the side pressure head and the corresponding auxiliary pressure head, and the symmetrically arranged side pressure heads and the corresponding auxiliary pressure heads cooperate to form a side pulling unit; before the lower pressure head moves downward to contact the bar, the synchronous connection head automatically establishes a limiting connection between the auxiliary pressure head and the corresponding side pressure head; during the process of the lower pressure head contacting the bar and pressing down for straightening, the auxiliary pressure head elastically presses the bar and moves along the axial direction of the bar away from the lower pressure head; under the limiting connection action of the synchronous connection head, the side pressure head moves synchronously along the axial direction of the bar following the auxiliary pressure head and elastically clamps the bar.

[0006] In a possible implementation manner, the synchronization association head includes a limiting member installed on the auxiliary pressure head and a limiting seat installed on the side pressure head. The limiting member automatically enters the limiting seat as the lower pressure head moves downward and automatically separates from the limiting seat as the lower pressure head moves upward.

[0007] In a possible implementation manner, the limiting member is cylindrical, and the limiting seat is a limiting groove with a flared guiding area at the entrance.

[0008] In a possible implementation manner, the auxiliary pressure head includes an elastic hinge rod that is inclined and hinged. A pressing wheel is rotatably installed at one end of the elastic hinge rod away from the hinge point. An annular limiting groove is formed on the pressing wheel. During the axial movement of the pressing wheel along the bar, the bar is always located within the limiting groove.

[0009] In a possible implementation manner, the side pressure head includes: a first sliding seat slidably installed on the support head along the axial direction of the bar; a second sliding seat horizontally arranged and elastically slidably installed on the first sliding seat along the radial direction of the bar; a contact column rotatably installed on the second sliding seat and in direct contact with the bar; a wedge-shaped limiting area provided on the support head and used to limit the second sliding seat, so that the second sliding seat gradually approaches the bar during the axial movement along the bar, and the contact column changes from a state of not contacting the bar to a state of elastically pressing the bar.

[0010] In a possible implementation manner, the first sliding seat is elastically and limitably slidably installed on the support head.

[0011] In a possible implementation manner, the end bearing joints are symmetrically distributed on both sides of the lower pressure head along the axial direction of the bar. The end bearing joints include receiving shafts that are horizontally arranged and symmetrically disposed along the radial direction of the bar and roll in the same direction. The area between the two symmetrically arranged receiving shafts is the receiving area, and the bar falls within the receiving area.

[0012] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: In a high-precision straightening machine for shaft-shaped bars provided by the embodiments of the present invention, during the process of straightening the bar by pressing down the bar with the lower pressing head, the side pressing head automatically establishes a limiting connection relationship with the auxiliary pressing head through the synchronous connection head and forms a side pulling unit. During the process of the side pulling unit contacting and pressing down the bar with the lower pressing head, the bar is automatically pulled outward from the outside of the lower support point, effectively reducing the elastic recovery after unloading, improving the straightening effect, correspondingly reducing the number of iterative cyclic straightening in the same area, shortening the straightening time, and improving the straightening efficiency; and the symmetric side pressing heads form an effective lateral constraint on the bar during the side pulling and resetting stages, effectively preventing the bar from shifting during the straightening and unloading processes, and at the same time effectively improving the stability and repeatability during the straightening process. Moreover, the side pulling unit does not require an additional driving source and is completely triggered by the pressing-down action of the lower pressing head, significantly simplifying the mechanism and improving the reliability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. is a schematic structural diagram of a lower pressing head, a support head, and an end bearing head of a high-precision straightening machine for shaft-shaped bars provided by an embodiment of the present invention.

[0014] Figure 2 FIG. is a schematic partial sectional structural diagram of a high-precision straightening machine for shaft-shaped bars provided by an embodiment of the present invention.

[0015] Figure 3 FIG. is a schematic structural diagram of an elastic hinge rod, a pressing wheel, a limiting member, a limiting seat, and a first sliding seat of a high-precision straightening machine for shaft-shaped bars provided by an embodiment of the present invention.

[0016] Figure 4 FIG. is a schematic structural diagram of a second sliding seat and a contact column of a high-precision straightening machine for shaft-shaped bars provided by an embodiment of the present invention.

[0017] Figure 5 FIG. is a schematic structural diagram of a wedge-shaped limiting area of a high-precision straightening machine for shaft-shaped bars provided by an embodiment of the present invention.

[0018] In the figure: 1, lower pressing head; 2, support head; 3, end bearing head; 4, auxiliary pressing head; 41, elastic hinge rod; 42, pressing wheel; 43, limiting groove; 44, elastic member; 5, side pressing head; 51, first sliding seat; 52, second sliding seat; 53, contact column; 54, wedge-shaped limiting area; 6, synchronous connection head; 61, limiting member; 62, limiting seat; 7, bar; 8, first mounting seat; 9, second mounting seat. DETAILED DESCRIPTION OF THE INVENTION

[0019] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be provided in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described below, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0020] Please refer to Figure 1 , a high-precision straightening machine for shaft-shaped bars, including a lower pressing head 1, a supporting head 2, and an end bearing joint 3. The supporting heads 2 are symmetrically arranged on the left and right to form two lower supporting points for supporting the bar 7. The lower pressing head 1 is arranged between the two lower supporting points and above the bar 7. The lower pressing head 1 moves downward to press the bar 7, and in combination with the support of the bar 7 by the two lower supporting points, the bar 7 is straightened by the three-point bending straightening method. Both the supporting head 2 and the lower pressing head 1 are installed to be lifted and lowered on an installation seat (not shown in the figure) that moves left and right. The installation seat moves left and right to the area to be straightened, then the supporting head 2 rises to a preset position to form a lower supporting point, and then the lower pressing head 1 presses down to straighten the bar 7. An arc-shaped groove is provided on both the lower pressing head 1 and the supporting head 2, and the bar 7 is located in the arc-shaped groove, thereby effectively preventing the bar 7 from shifting during the straightening process.

[0021] Refer to Figure 1 , Figure 3 and Figure 4 , auxiliary pressing heads 4 are symmetrically arranged on the left and right on the lower pressing head 1. The auxiliary pressing heads 4 are respectively located on both sides of the lower pressing head 1. On each side of the supporting head 2 away from the lower pressing head 1, side pressing heads 5 are symmetrically arranged in the front and back. The side pressing heads 5 are slidably connected to the supporting head 2 in the left-right direction. The symmetrically arranged side pressing heads 5 in the front and back are respectively located on both sides of the bar 7, and a synchronous connection head 6 is provided between the side pressing head 5 and the corresponding auxiliary pressing head 4. Before the lower pressing head 1 moves downward to contact the bar 7, the synchronous connection head 6 automatically establishes a limiting connection between the auxiliary pressing head 4 and the corresponding side pressing head 5, so that the corresponding side pressing head 5 moves outward synchronously with the auxiliary pressing head 4 to form a side pulling unit. The side pulling unit side pulls the bar 7 during the process of the lower pressing head 1 pressing and straightening, effectively reducing the elastic reset after straightening, improving the straightening effect, reducing the number of iterative cycle straightenings in the same area, correspondingly shortening the straightening time, and the side pulling unit is linked with the lower pressing head 1 without the need to add an independent drive, effectively improving the efficiency and stability of high-precision straightening.

[0022] Refer to Figure 1 , Figure 2 and Figure 3The lower pressure head 1 is fixedly connected to a mounting seat 8, and the auxiliary pressure head 4 includes an elastic hinge rod 41 arranged obliquely. The elastic hinge rod 41 is symmetrical on the left and right to form a regular eight-shaped structure. The upper end of the elastic hinge rod 41 is hingedly connected to the mounting seat 8, an elastic member 44 is connected between the middle part and the mounting seat 8, and a pressure wheel 42 is rotatably installed at the lower end. An annular limiting groove 43 is provided on the pressure wheel 42. When the lower pressure head 1 moves downward and contacts the rod 7, the pressure wheel 42 also contacts the rod 7 and the rod 7 is located in the limiting groove 43. Then, as the lower pressure head 1 moves downward, the pressure wheel 42 moves outward along the axial direction of the rod 7 (i.e., away from the lower pressure head 1) and exerts elastic force on the rod 7 under the action of the elastic member 44, wherein the limiting groove 43 on the pressure wheel 42 can limit the rod 7 in the front and rear directions, thereby improving the accuracy of its position and effectively preventing the rod 7 from shifting during the straightening process and affecting the straightening effect.

[0023] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The side of the support head 2 away from the lower pressure head 1 is fixedly connected with a mounting seat 2 9, and the side pressure head 5 includes a sliding seat 1 51, which is slidably mounted on the mounting seat 2 9 left and right, and a sliding seat 2 52 is elastically slidably mounted on the sliding seat 1 51 forward and backward. A contact column 53 is rotatably mounted on the side of the sliding seat 2 52 close to the rod 7, and a wedge-shaped limiting area 54 is provided on the mounting seat 2 9; the contact column 53 is located on the side of the pressure wheel 42 away from the lower pressure head 1; combined with Figure 4 and Figure 5 As shown, the sliding seat 2 52 is a connecting block fixedly connected with a sliding column, the sliding column is distributed from top to bottom and is slidably connected with the sliding seat 1 51 front and back, and the end of the sliding column that contacts the wedge-shaped limit area 54 is rotatably provided with a contact ball, and the wedge-shaped limit area 54 is located on the side of the sliding column away from the corresponding connecting block. When the side pressure head 5 moves outward with the auxiliary pressure head 4, the sliding column drives the connecting block to gradually move toward the direction of the rod 7 under the limitation of the wedge-shaped limit area 54, so that the contact column 53 gradually presses against the rod 7, and the front and rear symmetrical side pressure heads 5 form a clamping structure. Combined with the action of the auxiliary pressure head 4, the rod 7 is effectively pulled sideways and the rod 7 is suppressed from tilting upward, which effectively reduces the elastic recovery after unloading. Among them, when the side pressure head 5 is in the initial state, the contact column 53 does not contact the rod 7, so as to facilitate the lifting movement of the support head 2.

[0024] See also Figure 1 , Figure 3 and Figure 5 The synchronous associated head 6 includes a limit member 61 installed on the auxiliary pressure head 4 and a limit seat 62 installed on the side pressure head 5; Figure 3As shown, the limiting member 61 is shaft-shaped and passes through the elastic hinge rod 41 and is fixedly connected coaxially with the pressing wheel 42. The limiting seat 62 is a limiting groove with a flared guiding area at the entrance, and the limiting groove is formed on the first sliding seat 51. During the downward movement of the auxiliary pressing head 4 along with the downward pressing head 1, the limiting member 61 enters the limiting seat 62, automatically establishing a limiting connection. Then, the pressing wheel 42 drives the first sliding seat 51 to move synchronously along the axial direction of the bar 7. When the downward pressing head 1 moves upward, the limiting member 61 automatically separates from the limiting seat 62 along with the upward movement of the downward pressing head 1. Among them, an elastic reset member (not shown in the figure) is connected between the first sliding seat 51 and the second mounting seat 9, and the initial positions of both the first sliding seat 51 and the elastic hinge rod 41 are defined, facilitating their precise reset under the action of elastic force, and further facilitating the repeated establishment of the limiting connection state by the synchronous connecting head 6.

[0025] Referring to Figure 1 , the end bearing joints 3 are symmetrically distributed left and right, and the end bearing joints 3 include bearing shafts that are symmetrically arranged front and back and roll in the same direction. The first mounting seat 8 is located between the front and rear end bearing joints 3. The area between the two symmetric bearing shafts is the bearing area, and the bar 7 falls within the bearing area. This bearing area can automatically position the bar 7 and facilitate the picking and placing of the bar 7.

[0026] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0027] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "connected", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, an integral connection, or a sliding connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] The embodiments of the present specific implementation manners are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-precision straightening machine for shaft-shaped bars, comprising a lower pressing head, a supporting head and an end bearing joint. The supporting heads are symmetrically arranged to form two lower supporting points, and the lower pressing head is arranged above the middle of the two lower supporting points. It is characterized in that: The supporting head moves synchronously along the axial direction of the bar as the pressing head moves downward. Auxiliary pressing heads are symmetrically arranged on the pressing head and are located on both sides of the pressing head distributed along the axial direction of the bar. On one side of each supporting head away from the pressing head, side pressing heads are symmetrically arranged. A synchronous connection head is arranged between the side pressing head and the corresponding auxiliary pressing head, and the symmetrically arranged side pressing heads and the corresponding auxiliary pressing heads cooperate to form a side pulling unit. Before the pressing head moves downward to contact the bar, the synchronous connection head automatically establishes a limiting connection between the auxiliary pressing head and the corresponding side pressing head. During the process that the pressing head contacts the bar and presses downward for straightening, the auxiliary pressing head elastically presses the bar and moves along the axial direction of the bar away from the pressing head. Under the limiting connection action of the synchronous connection head, the side pressing head moves synchronously along the axial direction of the bar following the auxiliary pressing head and elastically clamps the bar.

2. The high-precision straightening machine for shaft-shaped bars according to claim 1, wherein: The synchronous connection head includes a limiting member installed on the auxiliary pressing head and a limiting seat installed on the side pressing head. The limiting member automatically enters the limiting seat as the pressing head moves downward and automatically separates from the limiting seat as the pressing head moves upward.

3. The high-precision straightening machine for shaft-shaped bars according to claim 2, characterized in that: The limiting member is cylindrical, and the limiting seat is a limiting groove with a trumpet-shaped guiding area at the entrance.

4. A high-precision straightening machine for shaft-shaped bars according to any one of claims 1-3, characterized in that: The auxiliary pressing head includes an elastic hinge rod arranged obliquely and hingedly. A pressing wheel is rotatably installed at one end of the elastic hinge rod away from the hinge point. An annular limiting groove is formed on the pressing wheel, and the bar is always located in the limiting groove during the movement of the pressing wheel along the axial direction of the bar.

5. A high-precision straightening machine for shaft-shaped bars according to any one of claims 1-3, characterized in that: The side pressing head includes: A first sliding seat, which is slidably installed on the supporting head along the axial direction of the bar; A second sliding seat, which is horizontally arranged and elastically slidably installed on the first sliding seat along the radial direction of the bar; A contact column, which is rotatably installed on the second sliding seat and is in direct contact with the bar; A wedge-shaped limiting area, which is arranged on the supporting head and is used to limit the second sliding seat, so that the second sliding seat gradually approaches the bar during the movement along the axial direction of the bar, and the contact column changes from a state of not contacting the bar to a state of elastically pressing the bar.

6. The high-precision straightening machine for shaft-like bars according to claim 5, characterized in that: The first sliding seat is elastically and limitedly slidably installed on the supporting head.

7. The high-precision straightening machine for shaft-shaped bars according to claim 2, wherein: The end bearing heads are symmetrically distributed on both sides of the pressing head along the axial direction of the bar. The end bearing head includes a bearing shaft that is horizontally and symmetrically arranged along the radial direction of the bar and rolls in the same direction, and the area between the two symmetric bearing shafts is a bearing area, and the bar falls within the bearing area.

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