Tiltable receiving seat and bend correction device

Abstract

To solve the problem that support portions may be deformed when a workpiece is supported at two points and is pressed near the center thereof in order to correct a hollow shaft.SOLUTION: In a receiving seat of a bend correction device according to the invention, a pushing portion at a tip of a punch is lowered in a state that a workpiece W is supported by receiving portions 41; and at a position between receiving seats for the workpiece W, the pushing portion pushes the workpiece by a predetermined amount, An amount that the punch is pushed in is an amount calculated in advance, taking conditions, such as spring back, into consideration with respect to the measured amount of bend, Since it is necessary to push the workpiece W more than an actual amount of correction, the receiving portion 41 swings so as to be tilted inward, and a state of surface contact with the workpiece W is maintained, After pushing the workpiece by the predetermined amount by means of the punch, bend is measured again by the sensor; and when the bend is confirmed as a result of the re-measurement, the workpiece W is supported again by the receiving portions 41 and pushed by the punch in order to correct the measured amount of bend, By repeating the above steps, the bends in the entire workpiece W are corrected.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a retractable support base and a bend straightening device suitable for straightening bends in long objects such as hollow metal pipes. [Background technology]

[0002] Conventionally, a device for straightening a bend in a metal bar is known, as described in Patent Document 1. This bend straightening device is equipped with support rolls that support both ends of a long workpiece, and a pressure roll that presses the part of the workpiece between the support rolls. The workpiece is automatically fed and supported by the support rolls, and the pressure roll presses the intermediate position of the supported part to straighten the bend in the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 1-278915 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, one example of a workpiece that requires straightening of a long object is a metal hollow shaft. Examples of hollow shafts that require straightening include the front fork of a motorcycle. However, when a conventional bending straightening device is used to straighten a hollow shaft, there is a concern that the supported parts may be deformed when the workpiece is supported at two points and pressure is applied near the center. The present invention has been made to solve this problem. [Means for solving the problem]

[0005] The receiving seat of the bend straightening device of the present invention is a receiving seat of a bend straightening device on which both ends of a hollow cylindrical long workpiece are placed and the workpiece is pressed with a punch to straighten the bend of the workpiece, and has a pair of receiving parts that support two specified points in the axial direction of the workpiece with their outer peripheral surfaces, and a support part that rotatably supports the receiving parts with a rotation axis that is perpendicular to the axial direction of the workpiece.

[0006] The corners of the receiving portion in the axial direction of the workpiece may be chamfered with a radius larger than the thickness of the workpiece. Also, a metal spring may be provided between the receiving portion and the support portion. [Brief description of the drawings]

[0007] [Figure 1] 1 is a configuration diagram showing a curve straightening device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a system configuration diagram of the bending straightening device shown in FIG. [Diagram 3] FIG. 2 is a configuration diagram showing the punch shown in FIG. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Diagram 5] FIG. [Figure 6] FIG. 6 is a partially enlarged view of FIG. 5. [Figure 7] FIG. 11 is an explanatory diagram showing a state in which a workpiece is placed on the receiving seat. [Figure 8] 4 is an explanatory diagram showing the operation of this bending straightening device. FIG. [Figure 9] 4 is an explanatory diagram showing the operation of this bending straightening device. FIG. [Figure 10] 4 is an explanatory diagram showing the operation of this bending straightening device. FIG. [Figure 11] FIG. 11 is a configuration diagram showing a receiving seat of a curve straightening device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Embodiment 1) FIG. 1 is a configuration diagram showing a bend straightening device according to a first embodiment of the present invention. FIG. 2 is a system configuration diagram of the bend straightening device. This bend straightening device 100 has a pair of core stocks 1 that support a hollow cylindrical, long workpiece rotatably from the left and right, and a servo motor that rotates the core stocks 1 together with the workpiece. A sensor 2 that detects the runout of the workpiece W is provided at the center position between the core stocks 1 on the bed 3. The sensor 2 is, for example, a touch probe or a reflective laser displacement meter. The core stock 1 has a conical tip and is inserted into the inside of the hollow pipe workpiece W to support the workpiece W substantially with its axis. The pair of core stocks 1 are provided on a core stock table on which the servo motor is arranged, and are fed manually or automatically in the axial direction of the workpiece W (not shown).

[0009] A pair of receiving seats 4 are arranged on the bed 3 to support the vicinities of both ends of the workpiece W. Furthermore, a punch 5 for pressing the workpiece W is provided at an upper position between the receiving seats 4 in the axial direction of the workpiece W. The curve straightening device 100 also has a control device 50 that controls servo motors and their drivers for moving the punch 5 and the workpiece W based on output signals from various encoders and sensors 2.

[0010] The control device 50 controls the driving of the sensor device that controls the movement and detection of the sensor 2, the servo motor for the core pusher, the servo motor for the punch, the linear rotary actuator 47 that moves the receiving table, and the like.

[0011] Fig. 3 is a configuration diagram showing the punch shown in Fig. 1. This punch 5 is composed of a pressing unit 6 provided at the lower end for pressing the workpiece W, and a moving unit 7 to which the pressing unit 6 is attached and which moves it up and down. The moving unit 7 has a column 9 fixed to a block of a linear guide 8, and the pressing unit 6 is fixed to the column 9. The column 9 is controlled to move by a ball screw and a servo motor (not shown). The servo motor is controlled by the control device 50.

[0012] As shown in FIG. 4, the pressing part 6 is block-shaped and the pressing surface 6a is a curved surface. The pressing part 6 has a separate pressing surface 6a so that the pressing surface 6a can be changed according to the diameter of the workpiece W. A rubber or resin protective layer 6b is provided on the pressing surface 6a. The rubber or resin is preferably one that is hard, abrasion-resistant, and chemical-resistant. For resin, for example, polyamide (nylon), polycarbonate, polyacetal (DuPont Delrin), polyaryl ether ketone (PEEK), polyphenylene sulfide (PPS) are used. For rubber, nitrile rubber, silicone rubber, etc. are used. The protective layer 6b reduces the local load on the workpiece W when pressed, and prevents deformation of the workpiece W. In addition, the workpiece W, which is a product, is not scratched.

[0013] 5 is a diagram showing the configuration of the receiving seat. The receiving seat 4 is composed of a block-shaped receiving portion 41, the receiving surface of which for the workpiece W is a curved surface, and support portions 42 that support the receiving portion 41 at both ends so that the receiving portion 41 can swing. The receiving portion 41 has a receiving base 43, the receiving surface of which is a separate part so that the receiving surface can be changed according to the diameter of the workpiece W, and the receiving base 43 is fixed to a holder portion 44 with bolts. The support portion 42 has a U-shaped cross section, and a rotating shaft 45 protrudes inward from both sides thereof, and the rotating shaft 45 is rotatably inserted into a hole in the holder portion 44.

[0014] As shown in the enlarged view of Fig. 6, a leaf spring 46 is fixed with a screw to the top surface of the holder part 44. A free end 46a of the leaf spring 46 abuts against the top surface 44a of the receiving base 43. The holder part 44 is held in a predetermined position by the action of the leaf spring 46. As will be described later, when the receiving base 43 oscillates during straightening of the workpiece W, the elasticity of the leaf spring 46 allows the receiving base 43 to oscillate, and even if it oscillates, the elasticity of the leaf spring 46 returns it to its original predetermined position. This makes it possible to straighten the workpiece W without changing its basic support state.

[0015] As shown in FIG. 7, the receiving table 43 has a width in the axial direction of the workpiece W that is approximately the radius of the workpiece W. The axial direction of the rotation shaft 45 is perpendicular to the workpiece W. The curvature (radius R2) of the receiving surface of the receiving table 43 is slightly larger than the curvature (radius R1) of the surface of the workpiece W. The corner of the receiving surface in the axial direction of the workpiece W is an R surface 43a. The R surface 43a is provided so that the surface of the workpiece W is not dented by the corner when the workpiece W is pressed. It is preferable that the radius R of the R surface 43a is larger than the plate thickness of the workpiece W. The receiving surface may be provided with a protective layer of rubber or resin, similar to the punch 5 (not shown).

[0016] The receiving seat 4 is moved stepwise in the vertical direction by a linear rotary actuator 47 and a height adjustment block body 48. A height adjustment block body 48 having step surfaces 48a to 48c is attached to a rod 47a of the linear rotary actuator 47. The step surfaces 48a to 48c are in three steps, and the steps are inclined between each step, and each step is continuous. The moving position of the rod 47a is controlled by a built-in servo motor. A base 49 supporting the receiving seat 4 is supported by the upper surfaces 48a to 48c of the steps at its lower surface. The first step surface 48a of the height adjustment block body 48 is at the lowest position, the second step surface 48b is at the intermediate position, and the third step surface 48c is at the highest position. The lower surface of the height adjustment block body 48 abuts against the upper surface of a column 51. As a result, the receiving seat 4 is supported by the column 51 via the height adjustment block body 48.

[0017] Fig. 8 is an explanatory diagram showing the operation of this bending correction device. First, the workpiece W is fixed from both sides by the tailstock 1 and rotated while the sensor 2 irradiates the workpiece W with a laser to measure the surface of the workpiece W and obtain the bending of the workpiece W. For example, as shown in Fig. 9, if bending occurs in one direction at the center position, the tailstock 1 is rotated so that the peak side of the bending is on top.

[0018] Next, the receiving seat 4 is raised to support both ends of the workpiece W. Here, since the workpiece W is bent in the axial direction, the surface of the workpiece W comes into contact with the corner of the receiving portion 41, but since the corner has a rounded surface 43a, it is possible to prevent the surface of the workpiece W from being dented. Furthermore, the rounded surface 43a comes into soft contact with the surface of the workpiece W, causing the receiving portion 41 to swing about the rotation axis 45 (the support state "before punching" in FIG. 9), and the receiving portion 41 widely supports the workpiece W.

[0019] Next, as described above, with the workpiece W supported by the receiving portion 41, the pressing portion 6 at the tip of the punch 5 is lowered, and the pressing portion 6 presses the workpiece W a predetermined amount at a position between the receiving seats 4 of the workpiece W. At this time, since a protective layer 6b of resin or the like is provided on the pressing surface 6a of the punch 5, the workpiece W is not pressed at a point or line, but is pressed by a surface due to the elastic deformation of the protective layer 6b. The pressing amount of the punch 5 is an amount calculated in advance by taking into account conditions such as springback to the bending amount measured above.

[0020] Since the workpiece W needs to be pushed more than the actual correction amount (pushed so that the mountain side becomes a valley), the receiving portion 41 swings so as to tilt inward as shown in FIG. 10 (support state of "punch push" in FIG. 9), and a surface contact state with the workpiece W is maintained. Even in this state, the workpiece W does not contact the corner of the receiving seat 4, so that the surface of the workpiece W can be prevented from being dented. After the punch 5 has been pushed by a predetermined amount, a certain amount of return occurs due to springback, and in this state, it is confirmed whether the bending of the entire workpiece W has been corrected. This confirmation is performed by rotating the workpiece W by the core pusher 1 and measuring the bending with the sensor 2, using the same procedure as above. If the bending is confirmed as a result of the remeasurement, the workpiece W is supported by the receiving portion 41 again and pressed by the punch 5 in order to correct the measured bending amount. By repeating this, the bending of the entire workpiece W is corrected.

[0021] As described above, the bend straightening device 100 of the present invention can prevent deformation of the hollow cylindrical workpiece W when straightening the bend of the workpiece W. This is particularly suitable for a workpiece W having a thin plate thickness.

[0022] (Embodiment 2) FIG. 11 is a configuration diagram showing a receiving seat of a straightening device according to the second embodiment of the present invention. The receiving seat 4 of this straightening device can be used by changing the shape of the receiving stand 43 so that the contact distance in the axial direction of the workpiece W can be selected. The receiving stand 43 shown in FIG. 11(a) is relatively narrow in the axial direction of the workpiece W. The receiving stand 43 shown in FIG. 11(b) has a simple structure and a normal width in the axial direction of the workpiece W. The receiving stand 43 shown in FIG. 11(c) is wide in the axial direction of the workpiece W and is used when the load is large, such as a workpiece with a large plate thickness. These receiving stands 43 are appropriately selected according to the type of workpiece W, and each is attached to a holder part 44 for use. In addition, the corner of the receiving surface in the axial direction of the workpiece W becomes an R surface 43a. [Explanation of symbols]

[0023] 100 Curve straightening device 1 Tailstock 2 Sensors 4 Receiving seat 5 Punch 42 Support part 43 Cradle 44 Holder part 45 Rotational axis 46 Leaf Spring 6 Pressing part 50 Control device

Claims

1. A receiving base for a straightening device for straightening a hollow cylindrical long workpiece by placing both ends of the workpiece on the receiving base and pushing the workpiece with a punch, A pair of receiving portions that support the workpiece at two predetermined points in the axial direction with their outer peripheral surfaces; A support portion that rotatably supports the receiving portion with a rotation axis perpendicular to an axial direction of the workpiece; A receiving seat for a bend straightening device having the above structure.

2. 2. The receiving seat for a bend straightening device according to claim 1, wherein a corner of the receiving portion in the axial direction of the workpiece is chamfered with a radius larger than a wall thickness of the workpiece.

3. 2. The receiving seat of the straightening device according to claim 1, further comprising a metal spring disposed between the receiving portion and the supporting portion.

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