Metal-sheet bending device

Abstract

The purpose of the present invention is to provide a metal-sheet bending device capable of smoothly and reliably bending metal sheets even in shapes such as an approximate J-shape. This metal-sheet bending device 10 comprises a pair of swinging members 13a, 13b and an upper die 17 that is provided above the swinging members so as to be capable of moving up and down along a bending center line. The metal-sheet bending device 10 is provided with a synchronization mechanism 20 that performs synchronous control such that the swinging members always swing at the same angle in mutually opposite directions. The synchronization mechanism includes a pair of first members 21a, 21b and a pair of second members 22a, 22b provided symmetrically with respect to the bending center line X. Each of the first members is provided so as to swing concentrically with the corresponding swinging member, and has first gear parts 23a, 23b on the outer periphery thereof. Each of the second members has second gear parts 27a, 27b always engaged with the corresponding first gear part and is provided such that the second gear parts are always engaged with each other on the bending center line.

Description

Metal plate bending equipment

[0001] The present invention relates to an apparatus used for bending metal sheets such as steel sheets, and in particular to an apparatus for bending a metal sheet at a central position between the pair of oscillating members by cooperating a lower die having a pair of oscillating members with a substantially semicircular cross section and an upper die that can be raised and lowered and applies a pressing force to a metal sheet placed on the pair of oscillating members toward the central position between the pair of oscillating members.

[0002] Patent Documents 1 to 3 listed below disclose known apparatuses in which a metal sheet to be bent is placed on the upper surfaces of a pair of oscillating members (or plate receiving members fixed thereon; the same applies hereinafter) at an origin position (the position shown in Figure 1 of Patent Document 1, Figure 2 of Patent Document 2, and Figure 3 of Patent Document 3) where the upper surfaces of the members are flush with each other, and an upper die is lowered from this state to press the metal sheet at the center position between the oscillating members, thereby rotating the pair of oscillating members in opposite directions and bending the metal sheet to a predetermined angle at this center position. Bending apparatuses of this type offer advantages such as superior bending accuracy compared to bending apparatuses of the type that use a fixed lower die, which have been used for a long time (see Figures 3 and 4 of Patent Document 1).

[0003] However, when a metal plate is bent from a flat state, the material undergoes plastic deformation, stretching particularly on its outer surface, causing misalignment between the metal plate and the oscillating member on which it is placed, resulting in scratches on the outer surface of the metal plate and reducing its commercial value.

[0004] To solve this problem, the present applicant has proposed a bending apparatus with a novel configuration in Patent Document 4 below that can efficiently bend metal sheets without leaving scratches on them. Specifically, the bending apparatus described in Patent Document 4 has a movable plate 35 mounted on each of a pair of oscillating members 32 so that it can slide relative to the upper surface of the member. Even if the metal sheet W undergoes plastic deformation during bending, the movable plate moves in accordance with the movement, preventing misalignment with the oscillating members and preventing scratches from being left on the outer surface of the metal sheet. The upper surface of the movable plate is completely flat and has no holes or openings, so no dents are left on the metal sheet. Therefore, the metal sheet can be bent completely without any damage, without compromising its commercial value. In addition, a spring forces the movable plate, and when the metal plate is plastically deformed during bending, the movable plate slides relative to the oscillating member in response. However, when the metal plate is removed from the lower die after bending, the spring's restoring force, which tries to return it to its original state, causes the movable plate to instantly return to its original position together with the oscillating member, ready for the next bending operation, resulting in good workability.

[0005] Japanese Utility Model Application Publication No. 3-14010 Japanese Patent Application Publication No. 2002-001435 Japanese Patent Application Publication No. 2002-120016 Japanese Patent Application Publication No. 2015-199120

[0006] Depending on the application of the product after bending the metal sheet, it may be necessary not only to bend the metal sheet into approximately two equal parts in the width direction, but also to bend it into a substantially J-shape as shown in Fig. 7. To manufacture such a substantially J-shaped metal product 40 using a conventional bending device 60 (Fig. 9(A)), in a standby state in which the upper surfaces of a pair of swing members 61a, 61b are aligned to provide a metal sheet mounting surface 62, the metal sheet W must be placed on the mounting surface 62 so that the bent portion of the metal sheet W (the portion that will become the bent portion 41 of the product 40) is directly below the upper die 63, and then bending must be performed.

[0007] At this time, the long side portion 42 of the approximately J-shaped product 40 exceeds the rotation center 64a of the oscillating member 61a and is placed in contact with almost the entire upper surface thereof, but only a small area of ​​the short side portion 43 near the bending center line X of the oscillating member 61b is placed on the upper surface thereof. In the conventional bending apparatus 60, the pair of oscillating members 61 a, 61 b ​​are arranged to be rotatable about rotation centers 64 a, 64 b independently of each other. Therefore, when the upper die 63 is lowered to bend the metal sheet W placed in this state, the long side portion 42 remains in close contact with the upper surface (metal sheet placing surface 62) of the oscillating member 61 a due to the pressing force of the upper die 63, but the short side portion 43 cannot maintain close contact with the upper surface (metal sheet placing surface 62) of the oscillating member 61 b. As a result, as shown in FIG. 9B , a point away from the bending center line X (a corner edge portion Wa of the metal sheet W corresponding to the lower corner at the tip of the short side portion 43) receives the concentrated pressing force, pushing down the oscillating member 61 b ​​and causing the oscillating member 61 b ​​to rotate significantly clockwise in the figure. As a result, it may be impossible to bend the metal sheet W into a substantially J-shape as shown in FIG. 7 .

[0008] Such a defect can occur not only when attempting to bend a metal sheet W into a generally J-shaped product 40 as shown in FIG. 7, but also when attempting to bend a product 50 in which one piece 53 (or both pieces 52, 53) of a pair of pieces 52, 53 sandwiching a bent portion 51 has a large notch 54, as shown in FIG.

[0009] Therefore, in view of the above background, the problem to be solved by the present invention is to provide a metal plate bending device that can smoothly bend a metal plate into a predetermined shape without causing the problems described above with reference to FIG. 9, even when attempting to bend products 40, 50 having shapes such as those shown in FIGS. 7 and 8.

[0010] In order to solve this problem, the present invention according to claim 1 provides a metal plate bending device comprising a pair of oscillating members arranged symmetrically about the bending center line of the main body, and an upper die arranged above the pair of oscillating members so as to be able to move up and down along the bending center line, and configured to bend the metal plate along the bending center line by lowering the upper die against a metal plate placed on a metal plate placing surface on the pair of oscillating members to oscillate in opposite directions to each other and applying a pressing force, wherein the device is characterized by being provided with a synchronization mechanism that synchronizes the pair of oscillating members so that they always oscillate in opposite directions by the same angle.

[0011] The present invention according to claim 2 is characterized in that, in the metal plate bending apparatus according to claim 1, the synchronization mechanism comprises a pair of first members and a pair of second members that are arranged symmetrically about the bending center line, each first member is arranged to oscillate concentrically together with a corresponding one of the oscillating members and has a first gear portion on its outer periphery, each second member has a second gear portion that always meshes with the first gear portion of the corresponding one of the first members, and the second gear portions of the pair of second members are arranged to always mesh with each other on the bending center line.

[0012] The present invention according to claim 3 is characterized in that, in the metal plate bending apparatus according to claim 2, each first member is an approximately semicircular gear fixed to the side of a corresponding one of the oscillating members concentrically with its center of rotation.

[0013] The present invention according to claim 4 is characterized in that in the metal plate bending apparatus according to claim 2 or 3, each second member is a substantially circular gear rotatably provided on the main body.

[0014] The present invention of claim 5 is characterized in that, in the metal plate bending processing device of claim 1 or 2, a movable plate is placed on each upper surface of a pair of oscillating members so as to be slidable, and the pair of movable plates are aligned flush with each other to provide the metal plate placing surface.

[0015] The metal plate bending device of the present invention is provided with a synchronization mechanism that synchronizes the pair of oscillating members so that they always oscillate in opposite directions by the same angle. Therefore, not only when bending a metal plate into approximately two equal parts in the width direction, but also when bending a roughly J-shaped product as shown in FIG. 7 or a product with a large notch as shown in FIG. 8, bending can be performed smoothly and reliably without causing the problems described in the prior art with reference to FIG. 9(B).

[0016] According to a preferred embodiment, the synchronization mechanism includes a pair of first members and a pair of second members that are symmetrically arranged about the bending centerline. Each first member is arranged to oscillate integrally with a corresponding oscillating member and has a first gear portion on its outer periphery, and each second member has a second gear portion that is constantly meshed with the first gear portion of the corresponding first member, and the second gear portions of the pair of second members are constantly meshed with each other on the bending centerline. By adopting such a configuration, the synchronization mechanism can reliably achieve the above-mentioned effect.

[0017] Furthermore, the present invention can also be applied to a bending device configured such that a movable plate is placed on the upper surface of each of a pair of oscillating members 32 so as to be relatively slidable, and in a standby state, the movable plates are flush with each other to form a metal plate placement surface on which a metal plate is placed and bent. As a result, even if the metal plate W undergoes plastic deformation during bending, the movable plate moves in accordance with the movement, and no misalignment occurs between the movable plate and the oscillating member, thereby preventing scratches from being left on the outer surface of the metal plate. In addition, the inclusion of the synchronization mechanism according to the present invention has the effect of enabling smooth and reliable bending without causing any problems when bending irregularly shaped products such as J-shaped products and notched products.

[0018] 1A is a front view showing a metal sheet bending apparatus according to an embodiment of the present invention in a standby state. The cover attached to the front is shown removed to show the internal mechanism. The upper die is also omitted. The rear view is a side view of the apparatus. The cross-sectional view is taken along the line A-A in FIG. 1B. The cross-sectional view is taken along the line B in FIG. 3B. Front views (A) to (C) are time-series front views showing an example of bending a metal sheet into a substantially J-shape as shown in FIG. 7 using this apparatus. While FIG. 6A shows a state (standby state) substantially similar to FIG. 1, some components are omitted in FIG. 6 because the focus of FIG. 6 is to explain the operation and function when bending is performed from this state. The side view (A) and perspective view (B) show enlarged examples of metal sheet shapes (after bending) that can be suitably bent using this apparatus. The side view (A) and perspective view (B) show enlarged examples of other metal sheet shapes (after bending) that can be suitably bent using this apparatus. 8A is a front view of a metal plate bending apparatus corresponding to the prior art of the present invention, and FIG. 8B is a front view showing a problem that occurs when attempting to bend a metal plate into a J-shape as shown in FIG. 7 using this apparatus.

[0019] Hereinafter, a metal plate bending apparatus 10 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0020] This metal plate bending apparatus (hereinafter referred to as the "apparatus") 10 has a main body 11. A pair of grooves 12a, 12b is formed on the top surface of the main body 11, symmetrically with respect to the bending center line X. Each groove 12a, 12b has a substantially semicircular cross-sectional shape, and oscillating members 13a, 13b, each having a substantially semicircular cross-sectional shape corresponding to the inner surface shape, are accommodated in the grooves 12a, 12b, respectively, thereby allowing the oscillating members 13a, 13b to oscillate about their respective rotation centers 14a, 14b. In this apparatus 10, a synchronization mechanism, which will be described later, synchronizes the pair of oscillating members 13a, 13b so that they always oscillate by the same angle in opposite directions.

[0021] The apparatus 10 further has an upper die 17 (not shown in FIGS. 1 to 5; see FIG. 6) that is provided above the oscillating members 13a and 13b and is movable up and down along the bending center line X. In the standby state (FIGS. 1 to 5 and 6(A)), the upper die 17 waits at a position (origin position) spaced above the oscillating members 13a and 13b, and is driven by a drive mechanism (not shown) to move downward from this origin position to bend the metal sheet W, and after the bending is completed, is moved upward again by the drive mechanism to return to the origin position.

[0022] The swinging members 13a, 13b are constantly biased by the coil springs 19a, 19b to maintain a standby state. When a downward pressing force from the upper die 17 acts on the bending center line X, the swinging members 13a, 13b swing in opposite directions against the biasing force of the coil springs 19a, 19b, opening at a predetermined angle (see FIGS. 6B and 6C). Each of the coil springs 19a, 19b is suspended between the main body 11 and each of the swinging members 13a, 13b. In this device 10, the upper ends of the springs 19a, 19b are connected to hooks 15a, 15b hooked onto the outer ends of the swinging members 13a, 13b, and the lower ends of the springs 19a, 19b are connected to bolts 16a, 16b fixed to the lower end of the main body 11. A V-groove 18 is formed on the top surface of the main body 11 between the pair of grooves 12a, 12b (on the bending center line X).

[0023] As described above, the apparatus 10 is provided with a synchronization mechanism 20 for synchronously controlling the pair of swinging members 13 a, 13 b so that they always swing by the same angle in opposite directions. The synchronization mechanism 20 provided in the illustrated apparatus 10 includes a pair of first members 21 a, 21 b with a substantially semicircular cross-sectional shape and a pair of second members 22 a, 22 b with a substantially circular cross-sectional shape, which are arranged symmetrically with respect to the bending center line X.

[0024] The first members 21a and 21b are fixed concentrically to the front side surfaces of the swinging members 13a and 13b, respectively, and are provided so as to swing integrally with the swinging members 13a and 13b. First gear portions 23a and 23b are engraved on the outer peripheral edges of the first members 21a and 21b over approximately half the circumference (reference numerals 23a1 and 23b1 indicate root circles of the first gear portions 23a and 23b, and reference numerals 23a2 and 23b2 indicate tip circles of the first gear portions 23a and 23b). In the illustrated device 10, an embodiment is adopted in which flanged shafts 24a, 24b are inserted into the front side surfaces of the oscillating members 13a, 13b from the front side at two points in the first members 21a, 21b that are approximately symmetrical with respect to a vertical line passing through the rotation centers 14a, 14b of the oscillating members 13a, 13b (and first members 21a, 21b), and these flanged shafts 24a, 24b are held from the rear side at the top of the main body 11 with mounting bolts 25a, 25b and mounting bushes 26a, 26b, thereby fixing the first members 21a, 21b to the oscillating members 13a, 13b.

[0025] The second members 22a and 22b are provided below the first members 21a and 21b, respectively. Second gear portions 27a and 27b are engraved on the outer peripheral edges of the second members 22a and 22b over substantially the entire circumference (reference numerals 27a1 and 27b1 indicate root circles of the second gear portions 27a and 27b, and reference numerals 27a2 and 27b2 indicate tip circles of the second gear portions 27a and 27b). These second gear portions 27a and 27b are always in mesh with each other, and the second gear portion 27a is always in mesh with the first gear portion 27a, and the second gear portion 27b is always in mesh with the first gear portion 23b. In the illustrated device 10, an embodiment is adopted in which flanged shafts 28a, 28b are inserted into the front side of the second members 22a, 22b from the front side at the point that becomes the center of rotation of the second members 22a, 22b, and these flanged shafts 28a, 28b are held from the rear side at the bottom of the main body 11 with mounting bolts 29a, 29b and mounting bushings 30a, 30b, thereby making the second members 22a, 22b rotatable around the flanged shafts 28a, 28b.

[0026] The operation and function of this apparatus 10 when bending a metal sheet W is basically the same as those of the prior art described in Patent Documents 1 to 4. That is, in the standby state shown in FIGS. 1 to 5 and 6(A), the metal sheet W to be bent is placed on a metal sheet mounting surface 31 formed by the upper surfaces of a pair of oscillating members 13a, 13b being horizontally flush with each other, and as the upper die 17 is lowered, its tip contacts the bending portion of the metal sheet W located on the bending center line X. As the upper die 17 is further lowered, the pair of oscillating members 13a, 13b rotate or oscillate in opposite directions about their rotation centers 14a, 14b against the tension spring bias of the coil springs 19a, 19b. As a result, the metal sheet W placed on the metal sheet mounting surface 31 is bent about the bending portion at an angle corresponding to the rotation angle of the oscillating members 13a, 13b.

[0027] The apparatus 10 configured as described above can smoothly and reliably bend not only when bending a metal plate into approximately two equal parts in the width direction, but also when bending an approximately J-shaped product 40 as shown in Fig. 7 or a product 50 having a large notch as shown in Fig. 8, without causing the problems described in the prior art with reference to Fig. 9(B). Below, with reference to Fig. 6, the operation and function of this apparatus 10 when bending an approximately J-shaped product 40 as shown in Fig. 7 will be described.

[0028] In this case, as shown in Figure 6 (A), when the device 10 is in a standby state (when the upper surfaces of the oscillating members 13a and 13b are flush with each other horizontally to form the metal plate mounting surface 31), the metal plate W is placed on the metal plate mounting surface 62 in a position where the part of the product 40 that will become the bending processing portion 41 is directly below the upper mold 17, and the upper mold 17 is lowered to perform the bending processing.

[0029] When the upper mold 13 is further lowered from the position shown in Figure 6(A), as shown in Figure 6(B), the swinging member 13a receives a downward pressing force and rotates in the counterclockwise direction as shown, and the swinging member 13b rotates in the clockwise direction as shown, and the metal sheet W is bent accordingly, and finally, as shown in Figure 6(C), the metal sheet W is bent at approximately 90 degrees at a portion along the bending center line X, and the J-shaped product 40 shown in Figure 4 is obtained.

[0030] As already mentioned, this device 10 is equipped with a synchronization mechanism 20 consisting of a pair of first members 21a, 21b that are fixed concentrically to the sides of the oscillating members 13a, 13b and oscillate together, and a pair of second members 22a, 22b that are rotatably mounted on the main body 11, and the first gear portions 23a, 23b of the first members 21a, 21b mesh with the second gear portions 27a, 27b of the second members 22a, 22b, respectively, and the second gear portions 27a, 27b of the second members 22a, 22b are positioned in a positional relationship such that they mesh with each other on the bending center line X.

[0031] When bending is performed using the device 10 equipped with this synchronization mechanism 20, the first gear portions 23a, 23b and the second gear portions 27a, 27b mesh with each other, and the second gear portions 27a, 27b mesh with each other, causing them to rotate in the directions shown by the arrows in Fig. 6(B) . In other words, the swinging members 13a, 13b always swing by the same angle in opposite directions, so that even when bending a substantially J-shaped product 40 or a notched product 50, poor bending (Fig. 9(B)) that occurs when bending is performed using the device 60 according to the prior art can always be performed satisfactorily.

[0032] Although a metal plate bending apparatus according to one embodiment of the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited thereto and can be modified or altered within the scope of the invention as defined by the claims.

[0033] For example, it is essential that the first members 21a, 21b are arranged concentrically with the oscillating members 13a, 13b so as to rotate or oscillate integrally therewith, but the specific configuration for this is not limited to the fixing method using flanged shafts 24a, 24b adopted in the illustrated embodiment, and a method of fixing the first members 21a, 21b to the side surfaces of the oscillating members 13a, 13b by welding, adhesive, or the like may also be adopted.

[0034] In the illustrated embodiment, the first members 21a, 21b are generally semicircular gears formed by cutting relatively large-diameter spur gears in half, and the second members 22a, 22b are generally relatively small-diameter spur gears, which is an advantageous embodiment in terms of easily designing the synchronization mechanism 20 at low cost, but other embodiments may be employed as long as they achieve the aforementioned action of the synchronization mechanism 20. For example, the ranges of the first gear portions 23a, 23b on the first members 21a, 21b and the ranges of the second gear portions 27a, 27b on the second members 22a, 22b do not necessarily have to be geared over the entire outer periphery, as long as the aforementioned meshing can be reliably achieved within the angular range over which the swinging members 13a, 13b swing.

[0035] In the illustrated embodiment, the sizes (diameters), shapes, positions, etc. of the first members 21a, 21b and the second members 22a, 22b, which are the main components of the synchronization mechanism 20, are merely examples, and can be arbitrarily changed as long as the meshing described above can be reliably achieved. For example, in the illustrated embodiment, the first members 21a, 21b are formed to have a diameter slightly smaller than that of the oscillating members 13a, 13b (thus, in FIG. 1 , arc lines indicating the outer edges of the oscillating members 13a, 13b are visible outside the tip circles 23a1, 23b1 of the first gear portions 23a, 23b). However, a design may be made in which the first members 21a, 21b have a smaller diameter and the second members 22a, 22b have a larger diameter than in the illustrated embodiment, so that the first gear portions 23a, 23b and the second gear portions 27a, 27b mesh with each other. Furthermore, in the illustrated embodiment, circular gears are used as the second members 22a, 22b, but as long as the above-mentioned meaning can be reliably achieved, they do not necessarily have to be circular gears, and they may have a semicircular or fan-shaped shape in which the second gear portions 27a, 27b are formed over a specified area.

[0036] The present invention is also applicable to the bending apparatus described in Patent Document 4 cited as the prior art, i.e., a bending apparatus configured such that a movable plate is placed on the upper surface of each of a pair of oscillating members 32 so as to be slidable relative to the upper surface of the pair of oscillating members 32, and that in a standby state, the movable plate is placed on a metal plate placing surface formed by the movable plates being flush and horizontal with each other, and the metal plate is placed on the metal plate placing surface to be bent. With a bending apparatus configured in this way, even if the metal plate W is plastically deformed during bending, the movable plate moves in accordance with the movement, and no misalignment occurs between the movable plate and the oscillating member, which has the advantage of preventing scratches on the outer surface of the metal plate. In addition, the inclusion of the synchronization mechanism of the present invention has the advantage of allowing smooth and reliable bending without causing any problems even when bending irregularly shaped products such as J-shaped products and notched products.

[0037] REFERENCE SIGNS LIST 10 Metal plate bending device 11 Main body 13a, 13b Oscillating member 14a, 14b Rotation center of oscillating member 19a, 19b Coil spring 20 Synchronizing mechanism 21a, 21b First member 22a, 22b Second member 23a, 23b First gear portion 27a, 27b Second gear portion 31 Metal plate placing surface 40 Approximately J-shaped metal product 50 Metal product with notch 60 Prior art metal plate bending device W Metal plate X Bending center line

Claims

1. A metal plate bending device comprising a pair of oscillating members arranged symmetrically about the bending center line of the main body, and an upper die arranged above the pair of oscillating members so as to be able to move up and down along the bending center line, and configured to bend the metal plate along the bending center line by lowering the upper die against a metal plate placed on the metal plate placing surface on the pair of oscillating members and applying a pressing force to the metal plate while oscillating the pair of oscillating members in opposite directions, characterized in that a synchronization mechanism is provided to synchronize the pair of oscillating members so that they always oscillate in opposite directions by the same angle.

2. The metal plate bending device according to claim 1, wherein the synchronizing mechanism comprises a pair of first members and a pair of second members arranged symmetrically about the bending center line, each first member being arranged to oscillate concentrically with a corresponding one of the oscillating members and having a first gear portion on its outer periphery, each second member having a second gear portion that is always in mesh with the first gear portion of the corresponding one of the first members, and the second gear portions of the pair of second members being always in mesh with each other on the bending center line.

3. A metal plate bending device according to claim 2, wherein each first member is a substantially semicircular gear fixed to the side of a corresponding one of the swinging members concentrically with its center of rotation.

4. The metal plate bending device according to claim 2 or 3, wherein each second member is a substantially circular gear rotatably mounted on the main body.

5. A metal plate bending device as claimed in claim 1 or 2, characterized in that a movable plate is slidably placed on the upper surface of each of a pair of oscillating members, and the pair of movable plates are aligned flush with each other to provide the metal plate placement surface.

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