SHEET MATERIAL FEEDING APPARATUS

Abstract

A sheet material feeding apparatus includes a first roll 106, and a second roll 108 arranged vertically below first roll 106, to feed a sheet material clamped between the first roll 106 and the second roll 108. The sheet material feeding apparatus further includes a first motor 102 provided with a rotatable first motor shaft 104 coupled to the first roll 106, and a second motor 103 provided with a rotatable second motor shaft 105 coupled to the second roll 108. The first motor shaft 104 and the second motor shaft 105 rotate at substantially the same rotation speed to allow the first roll 106 and the second roll 108 to rotate in synchronization with each other.

Claims

1. A sheet material feeding apparatus, comprising: a housing; a first roll accommodated in the housing; a second roll accommodated in the housing and arranged vertically below the first roll; a first motor provided with a rotatable first motor shaft coupled to the first roll; and a second motor provided with a rotatable second motor shaft coupled to the second roll, wherein a sheet material is fed while clamped between the first roll and the second roll, and the first motor shaft and the second motor shaft rotate at substantially the same rotation speed to allow the first roll and the second roll to rotate in synchronization with each other.

2. The sheet material feeding apparatus according to claim 1, wherein a difference between a moment of inertia of the first roll and that of the second roll is 0.01% or less.

3. The sheet material feeding apparatus according to claim 1, further comprising: a control device that transmits a control signal to at least one of the first motor and the second motor to rotate the first roll and the second roll in synchronization with each other.

4. The sheet material feeding apparatus according to claim 3, wherein the control device receives a signal of rotation speed of at least one of the first roll and the second roll to process the received signal of rotation speed.

5. The sheet material feeding apparatus according to claim 1, wherein the first motor shaft and the second motor shaft rotate in response to a signal received from outside the sheet material feeding apparatus.

6. The sheet material feeding apparatus according to claim 1, further comprising: a joining device that couples the second roll and the second motor shaft, the joining device allowing the second roll to be movable vertically with respect to the second motor shaft.

7. The sheet material feeding apparatus according to claim 6, further comprising: a roll support member that supports the second roll as well as having a lower end provided with a cam bearing; and a cam piston that engages with the cam bearing as well as being horizontally movable, wherein the cam bearing with which the cam piston is engaged moves vertically in response to movement of the cam piston to allow the second roll supported by the roll support member to be moved vertically in response to the vertical movement of the cam bearing to clamp or release the sheet material.

8. The sheet material feeding apparatus according to claim 7, further comprising: an eccentric cam that is rotatably coupled to the cam piston; and an eccentric cam bearing that supports the eccentric cam, the cam piston moving horizontally in response to rotation of the eccentric cam.

9. The sheet material feeding apparatus according to claim 5, wherein the second roll is movable vertically with respect to the second motor shaft in response to the signal received from outside.

10. The sheet material feeding apparatus according to claim 7, further comprising: a first elastic member that has an end fixed to the housing as well as a central portion fixed to the roll support member.

11. The sheet material feeding apparatus according to claim 10, further comprising: a second elastic member that has an end fixed to the housing as well as a central portion fixed to the roll support member, the second elastic member being arranged vertically below the first elastic member.

12. A method of feeding the sheet material by using the sheet material feeding apparatus according to claim 1.

13. A method of manufacturing a structure by working the sheet material fed by the method according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a sectional schematic view of a sheet material feeding apparatus of the present invention as viewed from front;

[0028] FIG. 2 is a schematic view showing a method of controlling motors of the sheet material feeding apparatus of the present invention;

[0029] FIG. 3 is a sectional schematic view of the sheet material feeding apparatus of the present invention when a sheet material is released, as viewed from side;

[0030] FIG. 4 is a sectional schematic view of the sheet material feeding apparatus of the present invention when the sheet material is clamped, as viewed from side;

[0031] FIG. 5 is an enlarged sectional schematic view of a portion A of FIG. 3;

[0032] FIG. 6 is an enlarged sectional schematic view of a portion A of FIG. 4; and

[0033] FIG. 7 is a perspective view showing a relationship among a roll shaft, a joining device, and a motor shaft of the sheet material feeding apparatus of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0034] Although an embodiment of the present invention will be described below with reference to drawings, the present invention is not limited to the embodiment.

[0035] The embodiment of the sheet material feeding apparatus of the present invention will be described with reference to FIGS. 1 to 7. A schematic view of a sheet material feeding apparatus 101 is shown in FIG. 1. The sheet material feeding apparatus 101 includes a housing 111, a first roll (upper roll 106) accommodated in the housing 111, and a second roll (lower roll 108) that is accommodated in the housing 111 and is arranged vertically below the upper roll 106. The upper roll 106 and the lower roll 108 are brought into contact with a sheet material 120 to clamp it, and then the upper roll 106 and the lower roll 108 rotate to feed the clamped sheet material 120. The sheet material feeding apparatus 101 includes a first motor (upper motor 102) provided with a rotatable first motor shaft (upper motor shaft 104), and a second motor (lower motor 103) provided with a rotatable second motor shaft (lower motor shaft 105). The upper motor shaft 104 is coupled to the upper roll 106 through an upper roll shaft 107, and the lower motor shaft 105 is coupled to the lower roll 108 through a lower roll shaft 109. Coupling by that way allows the upper roll 106 supported by upper roll bearings 117 to be rotated with respect to the housing 111 by the upper motor shaft 104, and the lower roll 108 supported by lower roll bearings 118 to be rotated with respect to the housing 111 by the lower motor shaft 105, and thus the rolls 106 and 108 are rotated by the motor shafts 104 and 105, respectively. As a result, the sheet material with large weight also can be fed, and thus the sheet material feeding apparatus 101 with high feeding capacity can be provided.

[0036] An eccentric flange 119 is attached to the housing 111 of the sheet material feeding apparatus 101, and the eccentric flange 119 includes a substantially cylindrical outer peripheral surface formed by centering an eccentric axis displaced from an axis of the upper roll 106, and a substantially cylindrical inner peripheral surface that is concentric with the axis of the upper roll 106. The upper roll shaft 107 supported by upper roll bearings 117 and provided at axially opposite ends of the upper roll 106 is rotatably attached to the housing 111 through the eccentric flange 119, and then the eccentric flange 119 is rotated around the eccentric axis with respect to the housing 111 to allow the upper roll 106 to be vertically displaced.

[0037] A difference between a moment of inertia of the upper roll 106 and a moment of inertia of the lower roll 108 is 0.01% or less, is preferably 0.005% or less, and is more preferably 0.001% or less. Equalizing the moment of inertia of the upper roll 106 and the moment of inertia of the lower roll 108 to each other equalizes a load of each of the motor shafts 104 and 105 with respect to one of the corresponding rolls 106 and 108, and thus rotating the upper motor shaft 104 and lower motor shaft 105 at substantially the same rotation speed facilitates rotating the upper roll 106 and lower roll 108 in synchronization with each other.

[0038] As shown in FIG. 2, the upper motor 102 and the lower motor 103 may be connected to a control device 121. The control device 121 may be arranged inside the sheet material feeding apparatus 101, or outside the sheet material feeding apparatus 101. The control device 121 is composed of a programmable logic controller (PLC), and the like. The control device 121 is programmed to enable control signals 122 and 123 to be outputted to the upper motor 102 and the lower motor 103, respectively. For example, if the upper motor shaft 104 and the lower motor shaft 105 are set to be rotated in synchronization with each other at a predetermined rotation speed, the control device 121 outputs the control signals 122 and 123 to the upper motor 102 and the lower motor 103, respectively, and then servo amplifiers provided in the upper motor 102 and the lower motor 103 process the control signals 122 and 123, respectively, thereby rotating the upper motor shaft 104 and the lower motor shaft 105 at the predetermined rotation speed.

[0039] The sheet material feeding apparatus 101 also includes a rotation angle sensor that measures rotation angles of the upper roll 106 and the lower roll 108 to detect rotation speeds thereof. The rotation angle sensor includes, for example, a magnetic resolver, and an optical encoder. The control device 121 receives signals 124 and 125 of the rotation speeds detected by the rotation angle sensor to determine whether the detected rotation speeds correspond to the predetermined rotation speed, and then outputs the control signals 122 and 123 to the upper motor 102 and the lower motor 103, respectively, so that the upper roll 106 and the lower roll 108 can be rotated at the predetermined rotation speed in synchronization with each other. In this way, controlling rotation speeds of the respective motor shafts 104 and 105 by using the control signals 122 and 123 based on determination of the rotation speeds 124 and 125 of the rolls 106 and 108, respectively, enables the respective rolls 106 and 108 to be rotated in synchronization with each other.

[0040] The sheet material feeding apparatus 101 may receive an external signal 126 so that the upper motor shaft 104 and the lower motor shaft 105 can be rotated in response to the external signal 126. For example, the sheet material feeding apparatus 101 may receive the signal 126 from a press apparatus that presses the sheet material 120 fed from the sheet material feeding apparatus 101. The control device 121 receives the external signal 126, and then can control the sheet material 120 to be fed from the sheet material feeding apparatus 101 so as to synchronize with a working process of an apparatus that works the fed sheet material 120, such as a press apparatus, by allowing the rolls 106 and 108 to be rotated through the control signals 122 and 123, respectively.

[0041] In FIG. 7, a perspective view illustrating a relationship among the lower roll shaft 109 of the lower roll 108, a joining device 110, and the lower motor shaft 105 of the lower motor 103, is shown. In the sheet material feeding apparatus 101, the lower roll shaft 109 and the lower motor shaft 105 are coupled to each other through the joining device 110. As the joining device 110, there is an available device that allows the lower roll 108 to be movable vertically upward through the lower roll shaft 109 when the sheet material 120 needs to be clamped, and that allows the lower roll 108 to be movable vertically downward through the lower roll shaft 109 when the sheet material 120 needs to be released. This kind of joining device includes an Oldham's coupling, for example. The joining device 110 can allow the lower roll 108 to be moved vertically without changing a position of the lower motor 103 to clamp or release the sheet material 120.

[0042] As shown in FIGS. 1 to 4, the sheet material feeding apparatus 101 includes a roll support member 116 in the housing 111, and the roll support member 116 rotatably supports opposite ends of the lower roll 108 through the lower roll bearings 118. The roll support member 116 is movable vertically together with the lower roll 108, or can be displaced vertically, and is vertically urged by elastic members 114 and 115. That is, the roll support member 116 is moved vertically to enable the sheet material 120 to be clamped or released without changing a position of the lower motor 103 by using the joining device 110. The roll support member 116 is provided at its lower end with cam bearings 113 that can roll. The cam bearing 113 includes a cam follower, and a roller follower, for example.

[0043] As shown in FIGS. 1 to 4, the sheet material feeding apparatus 101 includes a cam piston 112 that is movable horizontally and vertically to an axis of the lower roll 108. The cam piston 112 may be movable horizontally in a direction parallel to the axis of the lower roll 108. The cam piston 112 includes cam surfaces 112a, and engages with the cam bearings 113 through the respective cam surfaces 112a. Although FIGS. 3 and 4 each show the cam piston 112 including the two cam surfaces 112a that are spaced at a predetermined interval in the longitudinal direction, and that engage with the respective cam bearings 113, the numbers of the cam bearings and the cam surfaces are not limited to the numbers described above. The cam surface 112a of the cam piston 112 includes a first recessed portion 112b and a second recessed portion 112c recessed more than the first recessed portion 112b so as to allow the lower roll 108 to be movable vertically through the roll support member 116.

[0044] The cam piston 112, as shown in FIGS. 3 and 4, can be moved horizontally and vertically to the axis of the lower roll 108. In FIG. 3, when the cam piston 112 is moved in the arrow direction, each of the cam bearings 113 rolls along the cam surface 112a of cam piston 112, and then engages with the second recessed portion 112c of the cam surface 112a. Engagement of the cam bearing 113 and the second recessed portion 112c allows the roll support member 116 including the cam bearings 113 to be moved vertically downward while pressed downward by the elastic members 114 and 115 by a depth of the second recessed portion 112c from the first recessed portion 112b. As a result, the lower roll 108 is moved vertically downward to enable the sheet material 120 to be released. In FIG. 4, when the cam piston 112 is moved in the arrow direction, each of the cam bearings 113 rolls along the cam surface 112a of cam piston 112, and then engages with the first recessed portion 112b of the cam surface 112a. Engagement of the cam bearing 113 and the first recessed portion 112b allows the roll support member 116 including the cam bearings 113 to be moved vertically upward against elastic force of the elastic members 114 and 115 by a height of the first recessed portion 112b from the second recessed portion 112c. As a result, the lower roll 108 supported by the roll support member 116 is moved vertically upward to enable the sheet material 120 to be clamped. In FIGS. 1 to 4, although the two elastic members are arranged, one elastic member as well as three or more elastic members, are available. The elastic member may be a diaphragm.

[0045] As shown in FIGS. 1 to 4, the sheet material feeding apparatus 101 includes a rotatable eccentric cam 127 coupled to the cam piston 112, and an eccentric cam bearing 128 that supports the eccentric cam 127. Enlarged views of portions A in FIGS. 3 and 4 are shown in FIGS. 5 and 6, respectively. The eccentric cam 127 has a substantially columnar shape, and is supported by the eccentric cam bearing 128 so that an axis 127b of the substantially columnar shape is to be displaced from an axis of rotation 127a. When the eccentric cam 127 is rotated around the axis of rotation 127a of the eccentric cam 127 by a motor or the like, the axis 127b is positioned on a side opposite to the cam piston 112 with respect to the axis of rotation 127a in FIG. 5, and thus the cam piston 112 is moved in the arrow direction in FIG. 3 to allow each of the cam bearings 113 to roll into the second recessed portion 112c of the cam surface 112a. In FIG. 6, the axis 127b is positioned on the same side as the cam piston 112 with respect to the axis of rotation 127a, and thus the cam piston 112 is moved in the arrow direction in FIG. 4 to allow each of the cam bearings 113 to roll into the first recessed portion 112b of the cam surface 112a. In this way, the cam piston 112 is moved horizontally in response to the eccentric cam 127 rotating around the axis of rotation 127a to enable the sheet material 120 to be clamped or released at high speed. Using the eccentric cam in this way enables response from rotation of the eccentric cam to clamping and releasing of the sheet material to be performed at high speed, as well as enabling adjustment of the eccentric cam to be performed to stop rotation thereof halfway, for example.

[0046] The sheet material feeding apparatus 101 receives the external signal 126, and the eccentric cam 127 may be rotated in response to the external signal 126. For example, the sheet material feeding apparatus 101 may receive the signal 126 from a press apparatus that presses the sheet material 120 fed from the sheet material feeding apparatus 101. The control device 121 receives the external signal 126 to enable the sheet material feeding apparatus 101 to clamp or release the sheet material 120 to feed it to a processing apparatus so as to synchronize with a working process of the processing apparatus that works the sheet material 120 by rotating the eccentric cam 127 using a motor or the like to move the cam piston 112 horizontally to move the lower roll 108 supported by the roll support member 116 vertically.

[0047] Respective ends of the elastic members 114 and 115 are fixed to the housing 111, and respective central portions thereof are fixed to the roll support member. The elastic member 115 is arranged vertically below the elastic member 114. In this way, the sheet material feeding apparatus 101 includes the elastic members 114 and 115 to allow the elastic members 114 and 115 to urge the lower roll 108 for its vertical movement, but not to urge the lower roll 108 for its horizontal movement. As a result, it is possible to reduce horizontal runout of the lower roll 108 caused by inertial force generated when the lower roll 108 is rotated and horizontal inertial force generated when the sheet material 120 is fed.

[0048] In FIGS. 1 to 4, although the two elastic members 114 and 115 are arranged, only one of the elastic members 114 and 115 may be arranged, and an elastic member may be additionally arranged. Arranging the additional elastic member can further reduce the horizontal runout of the lower roll 108.

[0049] Using the sheet material feeding apparatus 101 of the present invention such as described above can feed the sheet material 120 at high speed as well as with high accuracy, and also can intermittently feed a predetermined amount of the sheet material 120. Subsequently, a processing apparatus, such as a press apparatus, applies a working process, such as press work, to the sheet material 120 fed from the sheet material feeding apparatus 101 at high speed as well as with high accuracy. As a result, it is possible to manufacture a small-sized component to be used in an information-related apparatus, such as a cellular phone and a personal computer, and a structure, such as a motor to be used in an automobile.

[0050] It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.