Metal plate bending device

Abstract

To provide a metal plate bending device capable of smoothly and reliably performing bending processing, even into substantially J-shapes and the like.SOLUTION: A metal plate bending device 10 comprises a pair of oscillating members 13a, 13b, an upper die 17 disposed above them so as to be vertically movable along a bending center line, and a synchronization mechanism 20 that synchronously controls the oscillating members so that they always oscillate by the same angle in opposite directions. The synchronization mechanism includes a pair of first members 21a, 21b and a pair of second members 22a, 22b, disposed symmetrically with respect to the bending center line X. Each first member is provided to oscillate concentrically and integrally with the corresponding oscillating member, and has first gear portions 23a, 23b on its outer periphery. Each second member has second gear portions 27a, 27b that always mesh with the corresponding first gear portions, and the second gear portions are arranged so as to always mesh with each other on the bending center line.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an apparatus used for bending metal plates such as steel plates, and in particular to an apparatus for bending a metal plate 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 plate placed on the pair of oscillating members toward the central position between the pair of oscillating members. [Background technology]

[0002] Patent Documents 1 to 3 listed below disclose known devices in which a metal sheet to be bent is placed on a pair of oscillating members (or plate receiving members fixed thereon; the same applies below) 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 devices of this type offer advantages such as superior bending accuracy compared to bending devices 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. This prevents 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 3-14010 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-001435 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-120016 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-199120 Summary of the Invention [Problem to be solved by the invention]

[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 an approximately J-shape as shown in Fig. 7. To manufacture such an approximately 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 in a position where 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 a conventional bending apparatus 60, a pair of oscillating members 61a, 61b are arranged to be rotatable independently of each other around rotation centers 64a, 64b. When an upper die 63 is lowered onto a metal plate W placed in this state to perform bending, the long side portion 42 remains in close contact with the upper surface (metal plate placing surface 62) of the oscillating member 61a, which is subjected to the pressing force of the upper die 63. However, the short side portion 43 cannot remain in close contact with the upper surface (metal plate placing surface 62) of the oscillating member 61b. As shown in FIG. 9(B), a point away from the bending center line X (a corner edge portion Wa of the metal plate W corresponding to the lower corner at the tip of the short side portion 43) receives the pressing force in a concentrated manner, pushing down the oscillating member 61b and causing the oscillating member 61b to rotate significantly clockwise in the figure. As a result, it may become impossible to bend the metal plate W into an approximately J-shape as shown in FIG. 7.

[0008] Such a defect can occur not only when attempting to bend a metal sheet W into an approximately J-shaped product 40 as shown in Figure 7, but also when attempting to bend a product 50 in which one of a pair of pieces 52, 53 sandwiching the bent portion 51 (or both pieces 52, 53) has a large notch 54, as shown in Figure 8.

[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 products 40, 50 having shapes such as those shown in Figures 7 and 8 into a predetermined shape without causing the problems described above with reference to Figure 9. [Means for solving the problem]

[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 integrally 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 of claim 3 is characterized in that, in the metal plate bending processing device of 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] A fourth aspect of the present invention is the metal plate bending device according to the second or third aspect, wherein 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 slidably placed on each upper surface of a pair of oscillating members, and the pair of movable plates are aligned flush with each other to provide the metal plate placing surface. [Effects of the Invention]

[0015] The metal plate bending device according to the present invention is provided with a synchronization mechanism that synchronizes a pair of oscillating members so that they always oscillate in opposite directions by the same angle. This means that bending can be performed smoothly and reliably 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 as shown in FIG. 7 or a product with a large notch as shown in FIG. 8, 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, which is effective in preventing scratches from being made 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 even when bending irregularly shaped products such as J-shaped products and notched products. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a front view showing a metal sheet bending apparatus according to an embodiment of the present invention in a standby state, in which a cover attached to the front is removed to show the internal mechanism, and an upper die is not shown. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 1A is a cross-sectional view taken along the line A-A in FIG. [Figure 5] FIG. 3B is a cross-sectional view taken along section B. [Figure 6] 6A to 6C are front views showing in time series an example of using this device to bend a metal plate into a roughly J-shape as shown in Fig. 7. Fig. 6A shows a state (standby state) that is essentially the same as Fig. 1, but since Fig. 6 is primarily intended to explain the operation and function when bending is performed from this state, some components are omitted from Fig. 6. [Figure 7] 1A and 1B are enlarged side and perspective views showing examples of shapes (after bending) of metal sheets that can be suitably bent using this apparatus. [Figure 8]1A and 1B are enlarged side and perspective views showing examples of other shapes of metal sheets (after bending) that can be suitably bent using this apparatus. [Figure 9] 8A is a front view of a metal plate bending device 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 device. DETAILED DESCRIPTION OF THE INVENTION

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

[0023] As described above, this device 10 is provided with a synchronization mechanism 20 for synchronously controlling the pair of oscillating members 13a, 13b so that they always oscillate by the same angle in opposite directions. The synchronization mechanism 20 provided in the illustrated device 10 includes a pair of first members 21a, 21b with a substantially semicircular cross-sectional shape and a pair of second members 22a, 22b 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 provided so as to always mesh with each other, the second gear portion 27a always mesh with the first gear portion 27a, and the second gear portion 27b always 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 bushes 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. 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. Further lowering causes the pair of oscillating members 13a, 13b to rotate or oscillate in opposite directions about their rotation centers 14a, 14b against the tension spring forces of the coil springs 19a, 19b. As a result, the metal sheet W placed on the metal sheet mounting surface 31 is bent around the bending portion at an angle corresponding to the rotation angle of the oscillating members 13a, 13b.

[0027] With the device 10 configured as described above, bending can be performed smoothly and reliably 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 device 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 placing surface 31), the metal plate W is placed on the metal plate placing 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 downward pressing force causes the oscillating member 13a to rotate counterclockwise and the oscillating member 13b to rotate clockwise, 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 along the bending center line X, thereby obtaining the J-shaped product 40 shown in Figure 4.

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

[0031] When bending is performed using device 10 equipped with this synchronization mechanism 20, the first gear portions 23a, 23b and 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, since oscillating members 13a, 13b always oscillate by the same angle in opposite directions, 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 device 60 according to the prior art can always be performed satisfactorily.

[0032] Although the 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, substantially semicircular gears formed by cutting a relatively large-diameter spur gear in half are used as the first members 21a, 21b, and relatively small-diameter spur gears are used as the second members 22a, 22b, which is an advantageous embodiment in terms of easily designing the synchronization mechanism 20 at low cost, but other embodiments may be adopted as long as the above-described action of the synchronization mechanism 20 is achieved. 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 above-described meshing can be reliably achieved within the angular range over which the swinging members 13a, 13b swing.

[0035] Furthermore, 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 is 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 addendum circles 23a1, 23b1 of the first gear portions 23a, 23b). However, a design may be made in which members having a smaller diameter are used as the first members 21a, 21b, and second members 22a, 22b having a larger diameter than in the illustrated embodiment are used, so that the first gear portions 23a, 23b and the second gear portions 27a, 27b mesh with each other. In addition, 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 predetermined 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 plates are flush and horizontal to form a metal plate mounting surface on which the metal plate is placed and 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. This 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. [Explanation of symbols]

[0037] 10 Metal plate bending device 11 Main unit 13a, 13b Swinging members 14a, 14b Rotation center of the swinging member 19a, 19b coil spring 20 Synchronization mechanism 21a, 21b First member 22a, 22b Second member 23a, 23b First gear part 27a, 27b Second gear part 31 Metal plate mounting surface 40. Roughly J-shaped metal products 50 Metal products with notches 60 Conventional metal plate bending device W Metal plate X-bending centerline

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, wherein the upper die is lowered against a metal plate placed on a metal plate placing surface on the pair of oscillating members to apply a pressing force thereby bending the metal plate along the bending center line 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. 2. The metal plate bending device according to claim 1, wherein the synchronization 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. 3. The metal plate bending device according to claim 2, wherein each of the first members is a substantially semicircular gear fixed to a side surface of a corresponding one of the swing members concentrically with the center of rotation of the swing member.

4. 4. The metal plate bending apparatus according to claim 2, wherein each of the second members is a substantially circular gear rotatably mounted on the main body.

5. 3. The metal plate bending device according to claim 1, wherein a movable plate is slidably placed on each upper surface of the 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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