Patent Description:
Conventionally, as disclosed in patent document <NUM> (<CIT>), box opening devices that transform a folded corrugated cardboard sheet into an opened state by holding two adjacent surfaces of the folded corrugated cardboard sheet respectively with holding parts, and changing a position of one of the holding parts that is holding one of the surfaces with respect to the other holding part that is holding the other surface. This type of box opening device can efficiently open corrugated cardboard sheets into boxes without relying on manpower.

<CIT> discloses a process for erecting a cardboard blank into the form of a case for the manufacture of a shipping-type cardboard box, together with equipment for its implementation. <CIT> discloses a plant and process for assembling, in the form of an open-ended box, a cardboard blank for the manufacture of a box of the American box type. <CIT> discloses a method and apparatus for erecting collapsed to folding cartons while holding a side wall by means of several holding suction elements, detecting the adjacent wall by means of several erecting suction elements and pivoting thereof in a vertical position to the side wall. <CIT> discloses a carton forming device capable of automatically feeding blank, the device composed of a four-bar linkage drive mechanism, a cam drive mechanism and an absorbing arm assembly. <CIT> discloses several implementations of a fan folding mechanism for folding flaps of a case into a fan fold arrangement, wherein according to one implementation, the fan folding mechanism comprises four shoes, arranged to allow one shoe to contact a flap on each of four sides of the case. <CIT> discloses an apparatus for removing a folding-box blank from a magazine and for erecting the same that has a first retaining means with means for gripping a first box wall of the blank and a second retaining means with means for gripping a second, adjacent box wall located on the same side of the blank. <CIT> discloses carton magazine capable of surely locating individual sections of a carried carton at a carton pulling-out port when pulling out the carton.

<CIT> discloses a box opening device according to the preamble of claim <NUM>.

For cases in which two adjacent surfaces of a corrugated cardboard sheet are held to open into a box, the corrugated cardboard sheet is opened into a box by rotating one of the held surfaces with respect to the other held surface about a boundary line (fold portion) between the two held surfaces. In other words, a box opening device such as that disclosed by patent document <NUM> (<CIT>), changes the position of the holding part holding the one surface with respect to the holding part holding the other surface so that the one of the held surface rotates with respect to the other held surface about the abovementioned boundary line. However, depending on the way for changing the position of the holding part, there are cases that the one held surface cannot smoothly rotates with respect to the other held surface about the abovementioned boundary line. In such cases, depending on the characteristics and state of the corrugated cardboard sheet, problems, such that the corrugated cardboard sheet (corrugated cardboard box) is damaged or deformed while the sheet is opening into a box, or opening into a box is failed due to release of the holding of the corrugated cardboard sheet at an unintended timing, may occur.

An object of the present invention is to provide a highly reliable box opening device which can reliably open a corrugated cardboard sheet into an opened state by holding two adjacent surfaces of the corrugated cardboard sheet respectively with holding parts and changing the position of a holding part that is holding the one surface with respect to another holding part holding the other surface without damaging or deforming the corrugated cardboard sheet.

A box opening device according to the first aspect of the present invention is provided with a first holding part, a second holding part, and a first holding part movement mechanism. The first holding part holds a first surface, which is one of two adjacent surfaces of a folded corrugated cardboard sheet. The second holding part holds a second surface, which is the other surface of the two adjacent surfaces of the corrugated cardboard sheet. The first holding part movement mechanism changes a position of the first holding part with respect to the second holding part and thereby transforms the corrugated cardboard sheet into an opened state. The first holding part movement mechanism has a support member that supports the first holding part so that the first holding part rotates on an arc track about a central axis of rotation that overlaps an imaginary line extending along a boundary line between the first surface and the second surface.

In the box opening device disclosed by patent document <NUM> (<CIT>), as illustrated in <FIG> of patent document <NUM> (<CIT>), the central axis of rotation of a suction pad that holds one of two adjacent surfaces of a corrugated cardboard sheet and is rotated in order to transform the corrugated cardboard sheet into an opened state, is not aligned with the boundary line (fold portion) between the two adjacent surfaces of the corrugated cardboard sheet. With such a configuration, the surface held by the rotating suction pad cannot smoothly turn about the abovementioned boundary line with respect to the surface held by the other suction pad. In other words, in the box opening device disclosed by patent document <NUM> (<CIT>), on the surface of the corrugated cardboard sheet held by the rotating suction pad, a force is also applied in a direction that is different from the direction (circumferential direction about the abovementioned boundary line as the central axis) in which the force should be applied to open the sheet into the box. Therefore, with the box opening device of patent document <NUM> (<CIT>), according to the characteristics and state of the corrugated cardboard sheet, problems, such that the corrugated cardboard sheet (corrugated cardboard box) is damaged or deformed during the sheet is opened into a box, or opening the sheet into a box is failed due to release of the holding of the corrugated cardboard sheet at an unintended timing, may occur.

In contrast, with the box opening device according to the first aspect of the present invention, a force can be applied on the first surface of a corrugated cardboard sheet held by the first holding part, solely in the direction in which a force should be applied to open the sheet into a box. Therefore, the corrugated cardboard sheet can be reliably opened into a box without damaging or deforming the corrugated cardboard sheet.

A box opening device according to the second aspect of the present invention is the box opening device according to the first aspect, wherein the central axis of rotation is immobile during rotation of the first holding part.

With the box opening device according to the second aspect of the present invention, it is easy to apply a force on the first surface of the corrugated cardboard sheet solely in the direction in which the force should be applied to open the sheet into a box, and it is therefore easy to reliably open the corrugated cardboard sheet into a box without damaging or deforming the corrugated cardboard sheet.

A box opening device according to the third aspect of the present invention is the box opening device according to the first aspect or the second aspect, wherein a distance between the central axis of rotation and the first holding part is constant during rotation of the first holding part.

With the box opening device according to the third aspect of the present invention, it is easy to apply a force on the first surface of the corrugated cardboard sheet solely in the direction in which the force should be applied to open the sheet into a box, and it is therefore easy to reliably open the corrugated cardboard sheet into a box without damaging or deforming the corrugated cardboard sheet.

A box opening device according to the fourth aspect of the present invention is the box opening device according to any of the first aspect to the third aspect, wherein the support member includes an arm member and a bearing. The first holding part is attached to the arm member. The bearing defines a central turning axis disposed on the imaginary line, and rotatably supports the arm member.

With the box opening device according to the fourth aspect of the present invention, the arm member to which the first holding part is attached is rotatably supported by the bearing, which has a central turning axis disposed on an imaginary line of the boundary line between the first surface and the second surface. Therefore, it is easy to apply a force on the first surface of the corrugated cardboard sheet solely in the direction in which the force should be applied to open the sheet into a box, and it is therefore easy to reliably open the corrugated cardboard sheet into a box without damaging or deforming the corrugated cardboard sheet.

A box opening device according to the fifth aspect of the present invention is the box opening device according to any of the first aspect to the third aspect, wherein the support member is a link mechanism. In an extension direction of the boundary line of the corrugated cardboard sheet that is opened by the first holding part movement mechanism, the link mechanism is disposed within a positional range at which the boundary line is present.

With the box opening device according to the fifth aspect of the present invention, in the extension direction of the boundary line of the corrugated cardboard sheet that is opened into a box, the link mechanism is disposed within the positional range at which the boundary line is present. Therefore, the box opening device can be made more compact in the direction along which the boundary line of the opened corrugated cardboard sheet extends.

A box opening device according to the sixth aspect of the present invention is the box opening device according to any of the first aspect to the fifth aspect and is further provided with a second holding part movement mechanism that rotates the second holding part about a prescribed rotation axis.

With the box opening device according to the sixth aspect of the present invention, the second holding part can also be rotated, and the second holding part can be moved with respect to the corrugated cardboard sheet. Therefore, the corrugated cardboard sheet supplied to the box opening device can be firmly held by the first holding part and the second holding part.

With the box opening device according to the present invention, a force can be applied on the first surface of the corrugated cardboard sheet held by the first holding part, solely in the direction in which a force should be applied to open the sheet into a box. Therefore, the corrugated cardboard sheet can be reliably opened into a box without damaging or deforming the corrugated cardboard sheet.

Embodiments for carrying out the box opening device according to the present invention are described with reference to the drawings. The embodiments described below are examples of the present invention, do not limit the technical scope of the present invention, and can be modified as appropriate.

In the description below, expressions such as top, bottom, front (front surface), back (rear surface), left and right may be used in order to describe positional relationships and orientation. Unless otherwise noted, the directions indicated by these expressions are in accordance with the directions of arrows illustrated in the drawings.

Furthermore, in the following description, expressions such as parallel, orthogonal, horizontal, vertical, and identical may be used, but these expressions do not refer to only relationships being parallel, orthogonal, horizontal, vertical, identical or the like in a strict sense. These expressions such as parallel, orthogonal, horizontal, vertical, and identical also include relationships being substantially parallel, orthogonal, horizontal, vertical, identical or the like.

A box manufacturing system <NUM> that includes a box opening device <NUM> according to a first embodiment of the present invention is described below.

<FIG> is a schematic side view (right side view) of the box manufacturing system <NUM> that includes the box opening device <NUM> according to the first embodiment of the present invention. <FIG> is a block diagram of the box manufacturing system <NUM> that includes the box opening device <NUM>.

The box manufacturing system <NUM> primarily includes a sheet supply unit <NUM>, a box-opening unit <NUM>, a bottom lid forming unit <NUM>, a box supply unit <NUM>, and a control unit <NUM> (see <FIG> and <FIG>). The control unit <NUM> is a common control unit for the sheet supply unit <NUM>, the box-opening unit <NUM>, the bottom lid forming unit <NUM>, and the box supply unit <NUM>. The control unit <NUM> controls the operation of each unit of the box manufacturing system <NUM>.

The box opening device <NUM> primarily has the box-opening unit <NUM> and the control unit <NUM> (see <FIG>). In the present embodiment, the box opening device <NUM> forms the box manufacturing system <NUM> together with the other units <NUM>, <NUM>, and <NUM>, but not limited to. The box opening device <NUM> may be a device which is independent from the other units <NUM>, <NUM>, and <NUM>. For example, the control unit <NUM> may be a control unit that is dedicated to the box-opening unit <NUM>. Furthermore, for example, the box-opening unit <NUM> may be supported by a frame that is different from a frame that supports the other units <NUM>, <NUM>, and <NUM>.

The box manufacturing system <NUM> transforms a folded corrugated sheet S into an opened state as illustrated in <FIG> and <FIG>, and forms a tubular corrugated cardboard box (hereinafter, referred to as a tubular corrugated cardboard box TB) (see <FIG>). The box manufacturing system <NUM> further forms a bottom lid BC on the tubular corrugated cardboard box TB, and thereby forms a corrugated cardboard box B with the top lid side opened. The box manufacturing system <NUM> then supplies the formed corrugated cardboard box B to a box packing device (not illustrated) that fills articles into the corrugated cardboard box B.

First, the tubular corrugated cardboard box TB and the corrugated cardboard sheet S are described with reference to <FIG> and <FIG>.

<FIG> is a perspective view of the tubular corrugated cardboard box TB. More specifically, <FIG> is a schematic perspective view that schematically depicts the tubular corrugated cardboard box TB, as viewed from the back left side of the box manufacturing system <NUM>, which is opened and formed by the box-opening unit <NUM>.

<FIG> illustrates the folded corrugated cardboard sheet S as viewed from one side, and <FIG> illustrates the folded corrugated cardboard sheet S as viewed from the other side. More specifically, <FIG> is a schematic rear view that schematically depicts a state that the box-opening unit <NUM> has received the folded corrugated cardboard sheet S supplied from the sheet supply unit <NUM>. <FIG> is a schematic front view that schematically depicts a state that the box-opening unit <NUM> has received the folded corrugated cardboard sheet S supplied from the sheet supply unit <NUM>.

As illustrated in <FIG>, the tubular corrugated cardboard box TB has primarily a side surface section T, top lid side flaps F2, and bottom lid side flaps F1.

The side surface section T forms the side surfaces of the corrugated cardboard box B. In the tubular corrugated cardboard box TB, the side surface section T has a square tube shape. As illustrated in <FIG>, the side surface section T includes a first side surface T1, a second side surface T2, a third side surface T3, and a fourth side surface T4. The first side surface T1, second side surface T2, third side surface T3, and fourth side surface T4 are annularly connected in this order (see <FIG>). In addition, the side surface section T has a first fold portion X12, a second fold portion X23, a third fold portion X34, and a fourth fold portion X41 (see <FIG>). The first fold portion X12 is arranged at the boundary between the first side surface T1 and the second side surface T2. The second fold portion X23 is arranged at the boundary between the second side surface T2 and the third side surface T3. The third fold portion X34 is arranged at the boundary between the third side surface T3 and the fourth side surface T4. The fourth fold portion X41 is arranged at the boundary between the fourth side surface T4 and the first side surface T1. In the tubular corrugated cardboard box TB, two adjacent side surfaces that sandwich each fold portion X12, X23, X34, and X41 are orthogonal to each other. In addition, the first side surface T1 and the third side surface T3 of the side surface section T are parallel, and the second side surface T2 and the fourth side surface T4 are parallel.

The top lid side flaps F2 are disposed at one opened side of the tubular side surface section T. The top lid side flaps F2 are flaps that are folded to form the top lid of the corrugated cardboard box B. The top lid formed by the top lid side flaps F2 closes an opening at one side of the side surface section T. As illustrated in <FIG>, the top lid side flaps F2 include a flap F21, a flap F22, a flap F23, and a flap F24. The flap F21 is connected to and extends from the first side surface T1. The flap F22 is connected to and extends from the second side surface T2. The flap F23 is connected to and extends from the third side surface T3. The flap F24 is connected to and extends from the fourth side surface T4.

The bottom lid side flaps F1 are disposed at one opening side of the side surface section T (a side that differs from the side at which the top lid side flaps F2 are disposed). The bottom lid side flaps F1 are flaps that are folded to form a bottom lid BC of the corrugated cardboard box B. The bottom lid BC formed from the bottom lid side flaps F1 closes an opening at one side of the side surface section T (an opening of the side that is opposite the opening closed by the top lid). As illustrated in <FIG>, the bottom lid side flaps F1 include a flap F11, a flap F12, a flap F13, and a flap F14. The flap F11 is connected to and extends from one end part of the first side surface T1 which is arranged opposite to the other end part of the first side surface T1 to which the flap F21 is connected. The flap F12 is connected to and extends from one end part of the second side surface T2 which is arranged opposite to the other end part of the second side surface T2 to which the flap F22 is connected. The flap F13 is connected to and extends from one end part of the third side surface T3 which is arranged opposite to the other end part of the third side surface T3 to which the flap F23 is connected. The flap F14 is connected to and extends from one end part the fourth side surface T4 which is arranged opposite to the other end part of the fourth side surface T4 to which the flap F24 is connected.

The corrugated cardboard sheet S is the form of the tubular corrugated cardboard box TB when folded into a planar shape (see <FIG> and <FIG>).

In the corrugated cardboard sheet S, the side surface section T, which has a square tubular shape when in the form of the tubular corrugated cardboard box TB, is folded into a planar shape.

More specifically, the corrugated cardboard sheet S is in a state in which the side surface section T is largely bent along two opposing fold portions (the first fold portion X12 and the third fold portion X34). The corrugated cardboard sheet S is bent so that the angles formed by two adjacent surfaces that sandwich the first fold portion X12 and the third fold portion X34 respectively become substantially <NUM>°. In other words, the corrugated cardboard sheet S is bent along the first fold portion X12 so that an inner wall of the first side surface T1 and an inner wall of the second side surface T2 are disposed adjacent to each other. Also, the corrugated cardboard sheet S is bent along the third fold portion X34 so that an inner wall of the third side surface T3 and an inner wall of the fourth side surface T4 are disposed adjacent to each other.

Furthermore, the corrugated cardboard sheet S is folded so that angles formed by two adjacent surfaces that sandwich the second fold portion X23 and the fourth fold portion X41 respectively become substantially <NUM>°. In the corrugated cardboard sheet S, the second fold portion X23 is in an opened state so that the inner wall of the second side surface T2 and the inner wall of the third side surface T3 are separated from each other. In addition, in the corrugated cardboard sheet S, the fourth fold portion X41 is in an opened state so that the inner wall of the fourth side surface T4 and the inner wall of the first side surface T1 are separated from each other.

In the folded corrugated cardboard sheet S, the first side surface T1, and the flap F21 and the flap F11 connected to the first side surface T1 are disposed on the same virtual plane. In addition, the second side surface T2, and the flap F22 and the flap F12 connected to the second side surface T2 are disposed on the same virtual plane. Furthermore, the third side surface T3, and the flap F23 and the flap F13 connected to the third side surface T3 are disposed on the same virtual plane. Moreover, the fourth side surface T4, and the flap F24 and the flap F14 connected to the fourth surface T4 are disposed on the same virtual plane.

The box manufacturing system <NUM> is described.

The box manufacturing system <NUM> forms a corrugated cardboard box B with a closed bottom lid BC while moving the corrugated cardboard sheet S and the tubular corrugated cardboard box TB, and supplies the formed corrugated cardboard box B to a box packing device (not illustrated).

The sheet supply unit <NUM> of the box manufacturing system <NUM> takes out one of corrugated cardboard sheet S stacked in a stack section <NUM> each time (see <FIG>), move the corrugated cardboard sheet S to the box-opening unit <NUM> positioned obliquely above and in front of the stack section <NUM> using a sheet movement mechanism (not illustrated) (see arrow D1 in <FIG>).

In the stack section <NUM>, multiple corrugated cardboard sheets S are stacked in a state that the bottom lid side flaps F1 side is oriented downward and the top lid side flaps F2 side is oriented upward. The corrugated cardboard sheets S are stacked in the stack section <NUM> such that the second side surface T2 and the third side surface T3 are arranged at the back side and the first side surface T1 and the fourth side surface T4 are arranged at the front side. Also, the corrugated cardboard sheets S are stacked in the stack section <NUM> such that the first side surface T1 and the second side surface T2 are arranged at the left side and the third side surface T3 and the fourth side surface T4 are arranged at the right side. While maintaining this posture (while maintaining a state in which the bottom lid side flaps F1 side is oriented downward, the top lid side flaps F2 side is oriented upward, the second side surface T2 and the third side surface T3 are arranged at the back side, the first side surface T1 and the fourth side surface T4 are arranged at the front side, the first side surface T1 and the second side surface T2 are arranged at the left side, and the third side surface T3 and the fourth side surface T4 are arranged at the right side), the sheet supply unit <NUM> supplies corrugated cardboard sheets S stacked in the stack section <NUM> to the box-opening unit <NUM>. Each time, the sheet supply unit <NUM> supplies a corrugated cardboard sheet S to the box-opening unit <NUM> to the same position so as not to cause the position aberration in the left-right direction.

The box-opening unit <NUM> unfolds the corrugated cardboard sheet S supplied by the sheet supply unit <NUM>, and transforms the corrugated cardboard sheet S into a tubular corrugated cardboard box TB. In other words, the box-opening unit <NUM> transforms that folded corrugated cardboard sheet S supplied by the sheet supply unit <NUM> to an opened state, and forms the tubular corrugated cardboard box TB. The box-opening unit <NUM> moves the opened corrugated cardboard sheet S (tubular corrugated cardboard box TB) forward (see arrow D2 in <FIG>), and delivers the opened corrugated cardboard sheet S to the bottom lid forming unit <NUM>. The box-opening unit <NUM> will be described in detail later.

The bottom lid forming unit <NUM> close the bottom lid side flaps F1 and form the bottom lid BC for the tubular corrugated cardboard box TB with a flap closure mechanism (not illustrated), and thereby forms the corrugated cardboard box B in which the opening at the bottom lid BC side is closed. More specifically, the bottom lid forming unit <NUM> fold, with a flap closure mechanism (not illustrated), the bottom lid side flaps F1 of the tubular corrugated cardboard box TB so that the flap F12 and the flap F14 are arranged at the inside and the flap F11 and the flap F13 are arranged at the outside while moving the tubular corrugated cardboard box TB with a movement mechanism (not illustrated) (see arrow D2 in <FIG>). That is, the flap closure mechanism of the bottom lid forming unit <NUM> first folds the flap F12 and the flap F14 of the bottom lid side flaps F1 so as to cover the bottom lid side opening of the side surface section T, and then folds the flap F11 and the flap F13 so as to cover the folded flap F12 and flap F14 from the outside. Furthermore, the bottom lid forming unit <NUM>, while moving the tubular corrugated cardboard box TB forward (see arrow D2 in <FIG>) with the movement mechanism (not illustrated), affixes a tape (not illustrated) to the fourth side surface T4, the flaps F11 and F13, and the second side surface T2 in this order with a tape affixing mechanism (not illustrated) so as to cover a gap between the folded flap F11 and flap F13, and thereby forms the bottom lid BC of the corrugated cardboard box B. The bottom lid forming unit <NUM> moves the corrugated cardboard box B with the formed bottom lid BC further forward (see arrow D2 in <FIG>) with the movement mechanism (not illustrated), and delivers the corrugated cardboard box B to the box supply unit <NUM>.

The method for forming the bottom lid by the flap closure mechanism of the bottom lid forming unit <NUM> is merely an example, and it is not limited thereto. For example, the flap closure mechanism may form the bottom lid BC by folding the bottom lid side flaps F1 in an interleaved manner without using tapes. For example, more specifically, the flap closure mechanism may form the bottom lid BC by folding in the bottom lid side flaps F1 so that a portion of the flap F12 overlaps the outside of the flap F11, a portion of the flap F13 overlaps the outside of the flap F12, a portion of the flap F14 overlaps the outside of the flap F13, and a portion of the flap F11 overlaps the outside of the flap F14.

The box supply unit <NUM> turns, with a turning mechanism (not illustrated), the corrugated cardboard box B whose opening faces upward and which is delivered from the bottom lid forming unit <NUM> in the clockwise direction (see arrow D3 in <FIG>) when viewed from the right side, so that the opening faces forward. Furthermore, the box supply unit <NUM> drops, with a dropping mechanism (not illustrated), the corrugated cardboard box B whose opening faces forward (see arrow D4 in <FIG>), and thereby supplies the box to the box packing device (not illustrated) located below.

The configuration of the box supply unit <NUM> is an example, and it is not limited thereto. For example, instead of dropping the corrugated cardboard box B whose opening faces forward, the box supply unit <NUM> may move the box upward or downward with an elevator mechanism (not illustrated) to supply the corrugated cardboard box B to the box packing device (not illustrated). Also, for example, in case that the box packing device is a type of device in which articles are packed into the corrugated cardboard box B whose opening faces upward, the box supply unit <NUM> may supply the corrugated cardboard box B to the box packing device without turning the corrugated cardboard box B (so that the opening remains facing upward).

The control unit <NUM> controls each unit of the box manufacturing system <NUM> including the sheet supply unit <NUM>, the box-opening unit <NUM>, the bottom lid forming unit <NUM>, and the box supply unit <NUM>. The control unit <NUM> will be described in detail later.

The box-opening unit <NUM> converts the corrugated cardboard sheet S received from the sheet supply unit <NUM> to an opened state. In other words, the box-opening unit <NUM> opens the folded corrugated cardboard sheet S, and forms the tubular corrugated cardboard box TB.

As illustrated in <FIG>, the box-opening unit <NUM> is arranged above and in front of the stack section <NUM> of the sheet supply unit <NUM>. As illustrated by the arrow D1 of <FIG>, the box-opening unit <NUM> receives the corrugated cardboard sheet S that is moved from an obliquely downward position, and opens the corrugated cardboard sheet S.

As illustrated in <FIG>, the box-opening unit <NUM> is provided with primarily a holding mechanism <NUM>, a first holding part movement mechanism <NUM>, a second holding part movement mechanism <NUM>, and a movement mechanism <NUM>.

The holding mechanism <NUM> receives the corrugated cardboard sheet S supplied from the sheet supply unit <NUM>, and holds the corrugated cardboard sheet S opened by the box-opening unit <NUM> (namely, the tubular corrugated cardboard box TB) until the opened corrugated cardboard sheet S is delivered to the bottom lid forming unit <NUM> for the next process.

The holding mechanism <NUM> includes two first suction cups <NUM>, two second suction cups <NUM>, a first suction drive unit <NUM>, and a second suction drive unit <NUM> (see <FIG> and <FIG>). The first suction cup <NUM> is an example of the first holding part. The second suction cup <NUM> is an example of the second holding part. The first suction cup <NUM> and the second suction cup <NUM> are made of rubber, however they are not limited thereto.

The numbers of first suction cups <NUM> and second suction cups <NUM> presented here are merely specific examples, and the numbers are not limited thereto. The number of the first suction cups <NUM> and the number of the second suction cups <NUM> may be respectively one, three or more. In addition, the number of first suction cups <NUM> and the number of second suction cups <NUM> do not have to be the same.

The first suction drive unit <NUM> is a vacuum generator for suctioning air from the space between a suction attachment surface 21b (see <FIG>) of the suction cup of each first suction cup <NUM> and the corrugated cardboard sheet S so that the first suction cups <NUM> stick to the side surface section T of the corrugated cardboard sheet S. The first suction drive unit <NUM> is a vacuum pump, however it is not limited thereto.

The second suction drive unit <NUM> is a vacuum generator for suctioning air from the space between a suction attachment surface 22b (see <FIG>) of the suction cup of each second suction cup <NUM> and the corrugated cardboard sheet S so that the second suction cups <NUM> stick to the side surface section T of the corrugated cardboard sheet S. The second suction drive unit <NUM> a vacuum pump, however it is not limited thereto.

The first suction cups <NUM> hold the first side surface T1 (side surface arranged at the front left side) of the folded corrugated cardboard sheet S supplied by the sheet supply unit <NUM> (see <FIG>). Each first suction cup <NUM> keeps holding the first side surface T1 of the corrugated cardboard sheet S without releasing it until the corrugated cardboard sheet S has been opened into a box by the box-opening unit <NUM> and is then delivered to the bottom lid forming unit <NUM>.

The first suction cups <NUM> are attached to a link mechanism <NUM> of the below-described first holding part movement mechanism <NUM> (see <FIG>). When the first suction cups <NUM> receives the corrugated cardboard sheet S supplied by the sheet supply unit <NUM>, the first suction cups <NUM> are moved by the link mechanism <NUM> from a position (standby position) such as that depicted in <FIG> in a bottom surface view, to a position (sheet receiving position) such as that depicted in <FIG>, so as to contact the first surface side T1 of the corrugated cardboard sheet S from the front (see <FIG>). When the first suction cups <NUM> contact the first side surface T1 of the corrugated cardboard sheet S from the front, the first suction cups <NUM> push the first side surface T1 of the corrugated cardboard sheet S rearward to make the corrugated cardboard sheet S, that is transferred by the sheet supply unit <NUM> in a state that the top part thereof inclined forward (see <FIG>), into a vertical state. In other words, when the first suction cups <NUM> contact the first side surface T1 of the corrugated cardboard sheet S from the front, the first suction cups <NUM> push the first side surface T1 of the corrugated cardboard sheet S rearward and change the orientation of the corrugated cardboard sheet S from a state that the top part thereof inclines forward to a state that the fold portion between side surfaces of the side surface section T (for example, the first fold portion X12 between the first side surface T1 and the second side surface T2) extends vertically. In the present embodiment, the first suction cups <NUM> contact the corrugated cardboard sheet S and change the orientation of the corrugated cardboard sheet S, but such an arrangement is not provided by way of limitation, and may be configured so that another member contacts the corrugated cardboard sheet S to change the orientation of the corrugated cardboard sheet S.

The first suction cups <NUM> are fixed at prescribed positions of the link mechanism <NUM> of the below-described first holding part movement mechanism <NUM> (see <FIG>). The attachment positions of the first suction cups <NUM> to the link mechanism <NUM> are determined so that the suction attachment surface 21b of each first suction cup <NUM> abuts an appropriate location of the first side surface T1 of the corrugated cardboard sheet S when the box-opening unit <NUM> receives the corrugated cardboard sheet S from the sheet supply unit <NUM>. Namely, the attachment positions of the first suction cups <NUM> to the link mechanism <NUM> are determined so that the suction attachment surface 21b of each first suction cup <NUM> abuts an appropriate location of the first side surface T1 of the corrugated cardboard sheet S when the first suction cups <NUM> supported by the link mechanism <NUM> in an orientation such as that depicted in <FIG> are arranged at positions like those depicted in <FIG>. It is preferable that the attachment positions of the first suction cups <NUM> to the link mechanism <NUM> are adjustable so that they can be changed according to the size, etc. of the corrugated cardboard sheet S.

The two first suction cups <NUM> are attached to the link mechanism <NUM> so that the first suction cups <NUM> stick to the first side surface T1 of the corrugated cardboard sheet S at the same height (see <FIG>). The positions at which the first suction cups <NUM> stick to the first side surface T1 are higher than a center position of the first side surface T1 in the height direction. The height positions at which the first suction cups <NUM> stick to the first side surface T1 are illustrative examples, which are not provided by way of limitation. For example, the attachment positions of the first suction cups <NUM> in the link mechanism <NUM>, or the shape of the link mechanism <NUM> may be designed so that two first suction cups <NUM> stick to the first side surface T1 at mutually different height positions.

The second suction cups <NUM> hold the second side surface T2 (side surface arranged at the back left side) adjacent to the first side surface T1 of the folded corrugated cardboard sheet S supplied by the sheet supply unit <NUM> (see <FIG>). Each second suction cup <NUM> keeps holding the second side surface T2 of the corrugated cardboard sheet S without releasing it until the corrugated cardboard sheet S has been opened into a box by the box-opening unit <NUM> and is then delivered to the bottom lid forming unit <NUM>.

The second suction cups <NUM> are attached to an arm member <NUM> of the below-described second holding part movement mechanism <NUM> (see <FIG>). When the second suction cups <NUM> receives the corrugated cardboard sheet S supplied by the sheet supply unit <NUM>, the second suction cups <NUM> are moved by the arm member <NUM> from a position (standby position) such as that depicted in <FIG>, to a position (sheet receiving position) such as that depicted in <FIG>, so as to contact the second surface side T2 of the corrugated cardboard sheet S from the back (see <FIG>).

In the present box opening device <NUM>, the first suction cups <NUM> contact the corrugated cardboard sheet S to change the orientation of the corrugated cardboard sheet S as described above, but such an arrangement is not provided by way of limitation. For example, the second suction cups <NUM> may be configured to contact the second side surface T2 of the corrugated cardboard sheet S to change the orientation of the corrugated cardboard sheet S. For cases in which the second suction cups <NUM> contact the second side surface T2 to change the orientation of the corrugated cardboard sheet S, the second suction cups <NUM> preferably contact at positions which are lower than the center position of the second side surface T2 of the corrugated cardboard sheet S in the height direction.

The first suction cups <NUM> are fixed at prescribed positions of the arm member <NUM> of the below-described second holding part movement mechanism <NUM> (see <FIG>). The attachment positions of the second suction cups <NUM> to the arm member <NUM> are determined so that the suction attachment surface 22b of each second suction cup <NUM> abuts an appropriate location of the second side surface T2 of the corrugated cardboard sheet S when the box-opening unit <NUM> receives the corrugated cardboard sheet S from the sheet supply unit <NUM>. Namely, the attachment positions of the second suction cups <NUM> to the arm member <NUM> are determined so that the suction attachment surface 22b of each second suction cup <NUM> abuts an appropriate location of the second side surface T2 of the corrugated cardboard sheet S when the second suction cups <NUM> supported by the arm member <NUM> and the below-described bearing <NUM> in an orientation such as that depicted in <FIG> are arranged at positions like those depicted in <FIG>. The attachment positions of the second suction cups <NUM> to the link mechanism <NUM> may be adjustable so that they can be changed according to the size, etc. of the corrugated cardboard sheet S.

The two second suction cups <NUM> are attached to the arm member <NUM> so that the second suction cups <NUM> stick to the second side surface T2 of the corrugated cardboard sheet S at the same height (see <FIG>). In addition, the two second suction cups <NUM> are attached to the arm member <NUM> so that the second suction cups <NUM> stick to at a height positions same as those of the two first suction cups <NUM>. The height positions at which the second suction cups <NUM> stick to the second side surface T2 are illustrative examples, which are not provided by way of limitation. For example, the attachment positions of the second suction cups <NUM> in the arm member <NUM>, or the shape of the arm member <NUM> may be designed so that two second suction cups <NUM> stick to the second side surface T2 at mutually different height positions. Furthermore, the attachment positions of the second suction cups <NUM> in the arm member <NUM>, or the shape of the arm member <NUM> may be designed so that two second suction cups <NUM> stick at height positions that differ from those of the first suction cups <NUM>.

The first holding part movement mechanism <NUM> changes the orientation of the first suction cups <NUM> with respect to the second suction cups <NUM>, and transforms the corrugated cardboard sheet S to an opened state.

The first holding part movement mechanism <NUM> primarily includes a link mechanism <NUM> and a link mechanism drive unit <NUM> (see <FIG> and <FIG>). The first holding part movement mechanism <NUM> is attached to a holding part movement mechanism support part <NUM> of a below-described movement mechanism <NUM> that is configured so as to be movable in the longitudinal direction, and is supported by the holding part movement mechanism support part <NUM> (see <FIG>).

The link mechanism drive unit <NUM> is connected to the link mechanism <NUM>, and drives the link mechanism <NUM>. The link mechanism drive unit <NUM> is an air cylinder (see <FIG>). The link mechanism drive unit <NUM> moves a rod 35a so that the rod 35a exits from a cylinder 35b or the rod 35a enters the cylinder 35b, and thereby drives the link mechanism <NUM> to which the rod 35a is coupled (see <FIG> and <FIG>). The link mechanism drive unit <NUM> is not limited to an air cylinder, and for example, may be a motor.

The link mechanism <NUM> is one example of the support member. The link mechanism <NUM> has a plurality of links <NUM>, and each link <NUM> is connected to another link through a joint (movable portion). In the present embodiment, as illustrated in <FIG> for example, five links <NUM> are connected by joints. The five links include a suction cup attachment link 32a to which two first suction cups <NUM> are attached, and a driven link 32b to which the rod 35a of the link mechanism drive unit <NUM> is connected. The link mechanism <NUM> illustrated in the present embodiment is merely one example of a specific configuration of the link mechanism, and is not limited to such a configuration. The link mechanism <NUM> may be configured so that the first suction cups <NUM> attached to the link mechanism can be operated in a manner described below.

The link mechanism <NUM> is configured so that it can change its state between a first state such as that depicted in <FIG> and <FIG>, and a second state such as that depicted in <FIG>. In the first state, the suction attachment surfaces 21b of the first suction cups <NUM> attached to the suction cup attachment link 32a are oriented to the right, and the two first suction cups <NUM> are aligned in the front-back direction. In the second state, the suction attachment surfaces 21b of the first suction cups <NUM> attached to the suction cup attachment link 32a are oriented to the back, and the two first suction cups <NUM> are aligned in the left-right direction.

When the box-opening unit <NUM> opens the corrugated cardboard sheet S, the rod 35a of the link mechanism drive unit <NUM> is driven so as to enter the cylinder 35b, and the state of the link mechanism <NUM> changes from the second state to the first state (see <FIG> and <FIG>). When the box-opening unit <NUM> opens the corrugated cardboard sheet S, the arm member <NUM> of the second holding part movement mechanism <NUM> is not moved, and the position of the second suction cup <NUM> does not change. That is, when the box-opening unit <NUM> opens the corrugated cardboard sheet S, the first holding part movement mechanism <NUM> changes, with respect to the second suction cups <NUM>, the position of the first suction cups <NUM> attached to the suction cup attachment link 32a of the link mechanism <NUM>. In other words, when the box-opening unit <NUM> opens the corrugated cardboard sheet S, the first holding part movement mechanism <NUM> changes, with respect to the second suction cups <NUM>, the positional relationship of the first suction cups <NUM> attached to the suction cup attachment link 32a of the link mechanism <NUM>. In addition, when the box-opening unit <NUM> opens the corrugated cardboard sheet S, the first holding part movement mechanism <NUM> changes, with respect to the second suction cups <NUM>, the direction in which the suction attachment surfaces 21b of the first suction cups <NUM> are oriented.

When the state of the link mechanism <NUM> is changed from the second state to the first state in order for the box-opening unit <NUM> to open the corrugated cardboard sheet S, each first suction cup <NUM> rotates on an arc track about a central axis of rotation R that overlaps an imaginary line IL (see <FIG>) extending along a boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S which is opened by the box-opening unit <NUM> (see <FIG>). When the state of the link mechanism <NUM> is changed from the second state to the first state, each first suction cup <NUM> rotates approximately <NUM> degrees about the central axis of rotation R (see <FIG>). As illustrated in <FIG>, the boundary line A between the first side surface T1 and the second side surface T2 is a line that overlaps the first fold portion X12, which is the boundary between the first side surface T1 and the second side surface T2. More specifically, for example, a center 21a of the circular first suction cup <NUM> (see <FIG>) rotates on an arc track as depicted by the two-dot chain line in <FIG>, about the central axis of rotation R, which overlaps the imaginary line IL that extends along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S that which is opened by the box-opening unit <NUM>. In other words, the link mechanism <NUM> supports the first suction cups <NUM> so that the first suction cups <NUM> rotate on an arc track about the central axis of rotation R that overlaps the imaginary line IL extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S which is opened by the box-opening unit <NUM>. During rotation of the first suction cups <NUM>, the central axis of rotation R is immobile. Also, during rotation of the first suction cups <NUM>, a distance between the central axis of rotation R and the first suction cup <NUM> (for example, the distance between the central axis of rotation R and the center 21a of the circular first suction cup <NUM>) is constant.

Furthermore, when the rod 35a of the link mechanism drive unit <NUM> is driven so as to exit from the cylinder 35b the state of the link mechanism <NUM> is changed from the first state to the second state (see <FIG> and <FIG>), the link mechanism <NUM> supports the first suction cups <NUM> so that the first suction cups <NUM> rotate on an arc track about the central axis of rotation R that overlaps the imaginary line IL extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S which is opened by the box-opening unit <NUM>.

In the extension direction (vertical direction in the present embodiment) of the boundary line A of the corrugated cardboard sheet S that is opened by the first holding part movement mechanism <NUM>, the link mechanism <NUM> is disposed within a positional range at which the boundary line A is present. In other words, as illustrated in <FIG>, a vertical direction height H1 of the link mechanism <NUM> is less than a vertical height Hs of the corrugated cardboard sheet S to be opened by the first holding part movement mechanism <NUM>. The height Hs is a length from the end part of the top lid side flaps F2 of the corrugated cardboard sheet S to the end part of the bottom lid side flaps F1. Furthermore, as in <FIG>, the vertical direction height H1 of the link mechanism <NUM> is less than a vertical direction height Ht of the side surface section T of the corrugated cardboard sheet S to be opened by the first holding part movement mechanism <NUM>. Furthermore, the entire link mechanism <NUM> is arranged between the upper end and the lower end of the side surface section T of the corrugated cardboard sheet S to be opened by the first holding part movement mechanism <NUM>. With such a configuration, the upper end position of the box-opening unit <NUM> can be restricted to be lower than the upper end position of the corrugated cardboard sheet S supplied to the box-opening unit <NUM>, and the size of the box-opening unit <NUM> in the height direction can be suppressed.

The second holding part movement mechanism <NUM> rotates the second suction cups <NUM> about a prescribed rotation axis P (see <FIG>).

The second holding part movement mechanism <NUM> includes primarily the arm member <NUM>, a turning shaft <NUM> coupled to the arm member <NUM>, a bearing <NUM> that rotatably supports the turning shaft <NUM>, a link <NUM>, and an arm drive unit <NUM> (see <FIG> and <FIG>). The second holding part movement mechanism <NUM> is attached to the holding part movement mechanism support part <NUM> of the below-described movement mechanism <NUM> that is configured to be movable in the front-back direction, and is supported by the holding part movement mechanism support part <NUM> (see <FIG>).

The bearing <NUM> rotatably supports the turning shaft <NUM> coupled to the arm member <NUM>, and thereby rotatably supports the arm member <NUM>.

The arm drive unit <NUM> is connected to the turning shaft <NUM> that is coupled to the arm member <NUM> through the link <NUM>, and drives the arm member <NUM>. The arm drive unit <NUM> is an air cylinder (see <FIG>). The arm drive unit <NUM> moves the rod 45a so that the rod 45a exits from the cylinder 45b or the rod 45a enters the cylinder 45b, and thereby drives the arm member <NUM> that is coupled to the rod 45a through the link <NUM> (see <FIG> and <FIG>). The link <NUM> is an elongated flat plate shaped member with one end side in the elongated direction coupled to the arm member <NUM> and the other end side in the elongated direction coupled to the rod 45a. The arm drive unit <NUM> is not limited to an air cylinder, and for example, may be a motor.

The arm member <NUM> is a member elongating in the horizontal direction and formed in a U-shape in cross-section (see <FIG>). Two second suction cups <NUM> are attached to the arm member <NUM> along the elongating direction thereof (see <FIG>).

The arm member <NUM> is configured so that it can change its state between a first state such as that depicted in <FIG>, and a second state such as that depicted in <FIG> and <FIG>. In the first state, the suction attachment surfaces 22b of the second suction cups <NUM> attached to the arm member <NUM> are oriented to the right, and the two second suction cups <NUM> are aligned in the front-back direction. In the second state, the suction attachment surfaces 22b of the second suction cups <NUM> attached to the arm member <NUM> are oriented to the front, and the two second suction cups <NUM> are aligned in the left-right direction.

When the rod 45a of the arm drive unit <NUM> is driven so as to enter the cylinder 45b, the arm member <NUM> rotates about the central turning axis of the turning shaft <NUM> that is rotatably supported by the bearing <NUM>, and the state of the arm member <NUM> changes from the first state to the second state. In addition, when the rod 45a of the arm drive unit <NUM> is driven so as to exit from the cylinder 45b, the arm member <NUM> rotates about the central turning axis of the turning shaft <NUM> that is rotatably supported by the bearing <NUM>, and the state of the arm member <NUM> changes from the second state to the first state. When the state of the arm member <NUM> changes from the first state to the second state, or from the second state to the first state, the second suction cups <NUM> rotate approximately <NUM> degrees about the rotation axis P that overlaps the central turning axis of the bearing <NUM> (see <FIG>). In other words, the second holding part movement mechanism <NUM> rotates the second suction cups <NUM> about the rotation axis P.

The movement mechanism <NUM> is a mechanism that moves the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> in the front-back direction. The movement mechanism <NUM> moves the tubular corrugated cardboard box TB by moving the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> while holding the tubular corrugated cardboard box TB with the first suction cups <NUM> and the second suction cups <NUM>.

The movement mechanism <NUM> includes primarily a belt drive unit <NUM>, the holding part movement mechanism support part <NUM>, and a belt mechanism <NUM>.

The first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> are attached to the holding part movement mechanism support part <NUM>. The holding part movement mechanism support part <NUM> is a member that supports the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM>. The holding part movement mechanism support part <NUM> is coupled to the belt mechanism <NUM> that functions as a power transmission mechanism. When the belt mechanism <NUM> is driven by the belt drive unit <NUM>, the holding part movement mechanism support part <NUM> moves forward and backward along the direction in which the belt of the belt mechanism <NUM> extends. When the holding part movement mechanism support part <NUM> is moved in the front-back direction, the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> attached to the holding part movement mechanism support part <NUM> also move in the front-back direction. Furthermore, when the holding part movement mechanism support part <NUM> is moved in the front-back direction, the corrugated cardboard sheet S (including a corrugated cardboard sheet S in the opened state), held by the first suction cups <NUM> attached to the first holding part movement mechanism <NUM> and the second suction cups <NUM> attached to the second holding part movement mechanism <NUM>, moves in the front-back direction.

More specifically, the movement mechanism <NUM> moves the holding part movement mechanism support part <NUM> forward with the belt mechanism <NUM>, and thereby moves the corrugated cardboard sheet S (tubular corrugated cardboard box TB), which has been opened by the first holding part movement mechanism <NUM>, forward to the bottom lid forming unit <NUM>. Furthermore, after the tubular corrugated cardboard box TB has been delivered to the bottom lid forming unit <NUM>, the movement mechanism <NUM> moves the holding part movement mechanism support part <NUM> rearward with the belt mechanism <NUM>, and thereby moves the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> rearward. More specifically, after delivering the tubular corrugated cardboard box TB to the bottom lid forming unit <NUM>, the movement mechanism <NUM> moves the holding part movement mechanism support part <NUM>, which supports the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM>, rearward so that first suction cups <NUM> and the second suction cups <NUM> return to the position for receiving the corrugated cardboard sheet S supplied from the sheet supply unit <NUM>.

In the following description, the position at which the holding part movement mechanism support part <NUM> is arranged in order to arrange the first suction cups <NUM> and the second suction cups <NUM> at the position for receiving a corrugated cardboard sheet S supplied from the sheet supply unit <NUM> is referred to as the first position. Furthermore, the position at which the holding part movement mechanism support part <NUM> is arranged when delivering the tubular corrugated cardboard box TB to the bottom lid forming unit <NUM> is referred to as the second position.

The control unit <NUM> is one example of a control unit for controlling the box opening device <NUM>. In the present embodiment, the control unit <NUM> controls not only the operation of the box-opening unit <NUM> of the box opening device <NUM>, but also the operations of the sheet supply unit <NUM>, the bottom lid forming unit <NUM>, and the box supply unit <NUM>.

As illustrated in <FIG>, the control unit <NUM> is electrically connected to each constituent element of the box-opening unit <NUM> including the first suction drive unit <NUM>, the second suction drive unit <NUM>, the link mechanism drive unit <NUM>, the arm drive unit <NUM>, and the belt drive unit <NUM>. The control unit <NUM> is also electrically connected to the sheet supply unit <NUM>, the bottom lid forming unit <NUM> and the box supply unit <NUM>.

As illustrated in <FIG>, the control unit <NUM> primarily includes a storage unit <NUM> and a control part <NUM>.

The storage unit <NUM> is configured from ROM, RAM, and a hard disk drive (HDD) and so on. For example, various programs executed by the control part <NUM> are stored in the storage unit <NUM>. In addition, for example, various types of information, such as various parameters for control, necessary for the control part <NUM> to control the box manufacturing system <NUM> are stored in the storage unit <NUM>.

The control part <NUM> is configured primarily from a CPU/CPUs. The control part <NUM> reads and executes a program/programs stored in the storage unit <NUM>, and controls the operation of each constituent element of the box-opening unit <NUM> including the first suction drive unit <NUM>, the second suction drive unit <NUM>, the link mechanism drive unit <NUM>, the arm drive unit <NUM>, and the belt drive unit <NUM>. The control part <NUM> also reads and executes a program/programs stored in the storage unit <NUM> to control the sheet supply unit <NUM>, the bottom lid forming unit <NUM> and the box supply unit <NUM>.

As a control of the box-opening unit <NUM>, the control unit <NUM> controls, for example, the operations of the first suction drive unit <NUM> and the second suction drive unit <NUM> in order to switch between holding and releasing of the side surface section T of the corrugated cardboard sheet S by the first suction cups <NUM> and the second suction cups <NUM>. In addition, for example, the control unit <NUM> controls the operations of the link mechanism drive unit <NUM> and the arm drive unit <NUM> in order to change the position (orientation) of the first suction cups <NUM> and the second suction cups <NUM>. The control unit <NUM> also controls the operation of the belt drive unit <NUM> in order to deliver the corrugated cardboard sheet S (tubular corrugated cardboard box TB ) in an opened state to the bottom lid forming unit <NUM>. The specific control of the operation of the box-opening unit <NUM> by the control unit <NUM> will be described later.

The operation for opening the corrugated cardboard sheet S into a box using the box opening device <NUM> is described while referencing the flowchart of <FIG>. The box opening operation described below is merely one example, and it is not limited thereto.

First, the state of each constituent element of the box-opening unit <NUM> before the box opening operation is started (before the corrugated cardboard sheet S is supplied by the sheet supply unit <NUM>) is described. Before the box opening operation is started, the holding part movement mechanism support part <NUM> is arranged at the above-described first position. The link mechanism <NUM> is in the above-described first state. The arm member <NUM> is in the abovementioned first state. That is, before the box opening operation is started, the box-opening unit <NUM> is in a state such as that depicted in <FIG>.

At first, in step S1, the sheet supply unit <NUM> that is controlled by the control unit <NUM> supplies a corrugated cardboard sheet S to the box-opening unit <NUM> as a preliminary step for the box opening operation of the box opening device <NUM>. That is, in step S1, the sheet supply unit <NUM> controlled by the control unit <NUM> moves the corrugated cardboard sheet S to the position at which the corrugated cardboard sheet S is handed over to the box-opening unit <NUM>.

Next, in step S2, the control unit <NUM> controls the link mechanism drive unit <NUM> of the first holding part movement mechanism <NUM>, and changes the state of the link mechanism <NUM> from the first state to the second state (see <FIG>). As a result, the first suction cups <NUM> attached to the link mechanism <NUM> contact the first side surface T1 of the corrugated cardboard sheet S from the forward side, and the orientation of the corrugated cardboard sheet S is changed (so that the corrugated cardboard sheet S is in a vertically extended state). Also, in step S2, the control unit <NUM> controls the arm drive unit <NUM> of the second holding part movement mechanism <NUM>, and changes the state of the arm member <NUM> from the first state to the second state (see <FIG>). As a result, the second suction cups <NUM> attached to the arm member <NUM> contact the second side surface T2 of the corrugated cardboard sheet S from the rearward side. The timing of the operation of the link mechanism <NUM> and the arm member <NUM> is appropriately determined so that a state is formed in which the corrugated cardboard sheet S is sandwiched by the first suction cups <NUM> and the second suction cups <NUM> (see <FIG>).

Next, in step S3, the control unit <NUM> operates the first suction drive unit <NUM> and the second suction drive unit <NUM> so that the first suction cups <NUM> stick and hold the first side surface T1 of the corrugated cardboard sheet S, and the second suction cups <NUM> stick and hold the second side surface T2 of the corrugated cardboard sheet S. Note that the timing of the step S2 and timing of the step S3 may be partially or entirely overlapped.

Next, in step S4, the control unit <NUM> controls the link mechanism drive unit <NUM> of the first holding part movement mechanism <NUM>, and changes the state of the link mechanism <NUM> from the second state to the first state (see <FIG>). As a result, the first suction cups <NUM> attached to the link mechanism <NUM> rotate on an arc track about the central axis of rotation R that overlaps the imaginary line IL (see <FIG>) extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S that the first holding part movement mechanism <NUM> is going to open (see <FIG>). As a result, as illustrated in <FIG>, the corrugated cardboard sheet S comes to an opened state. Because the first suction cups <NUM> rotates on an arc track about the central axis of rotation R as shown above, only a force necessary to open the first side surface T1 with respect to the second side surface T2 around the first fold portion X12 acts on the first side surface T1 that is held by the first suction cups <NUM>. In other words, because the first suction cups <NUM> rotates on an arc track about the central axis of rotation R, a force in a direction orthogonal to the suction attachment surfaces 21b of the first suction cups <NUM> is less susceptible to act the first side surface T1 that is held by the first suction cups <NUM>. As a result, the corrugated cardboard sheet S can be reliably opened into a box without being damaged or deformed.

Next, in step S5, the control unit <NUM> operates the belt drive unit <NUM>, and moves the holding part movement mechanism support part <NUM> forward from the first position to the second position. As a result, the first holding part movement mechanism <NUM> and the second holding part movement mechanism <NUM> attached to the holding part movement mechanism support part <NUM> also move forward. Furthermore, the tubular corrugated cardboard box TB that is held by the first suction cups <NUM>, supported by the link mechanism <NUM> of the first holding part movement mechanism <NUM> and by the second suction cups <NUM> supported by the arm member <NUM> of the second holding part movement mechanism <NUM>, is moved to the bottom lid forming unit <NUM>.

Next, in step S6, the control unit <NUM> stops the operation of the first suction drive unit <NUM> and the second suction drive unit <NUM> so that holding of the corrugated cardboard sheet S by the first suction cups <NUM> and the second suction cups <NUM> is canceled. As a result, the tubular corrugated cardboard box TB is delivered to the bottom lid forming unit <NUM>.

Next, in step S7, the control unit <NUM> controls the arm drive unit <NUM> of the second holding part movement mechanism <NUM>, and changes the state of the arm member <NUM> from the second state to the first state.

Next, in step S8, the control unit <NUM> operates the belt drive unit <NUM>, and moves the holding part movement mechanism support part <NUM> rearward from the second position to the first position.

The order of step S7 and step S8 may be reversed, or step S7 and step S8 may be simultaneously executed.

The abovementioned steps S1 to S8 are executed to each of the corrugated cardboard sheets S.

(<NUM>-<NUM>) The box opening device <NUM> according to the abovementioned embodiment is provided with the first suction cups <NUM> as an example of the first holding part, the second suction cups <NUM> as an example of the second holding part, and the first holding part movement mechanism <NUM>. The first suction cups <NUM> hold the first side surface T1, which is one of two adjacent surfaces (the first side surface T1 and the second side surface T2) of the folded corrugated cardboard sheet S. The second suction cups <NUM> hold the second side surface T2, which is the other of the two adjacent surfaces of the corrugated cardboard sheet S. The first holding part movement mechanism <NUM> changes the position of the first suction cups <NUM> with respect to the second suction cups <NUM> and thereby transforms the corrugated cardboard sheet S to an opened state. That is, the first holding part movement mechanism <NUM> changes the position of the first suction cups <NUM> with respect to the second suction cups <NUM> and opens the corrugated cardboard sheet S to form the tubular corrugated cardboard box TB. The first holding part movement mechanism <NUM> has the link mechanism <NUM> as one example of the support member. The link mechanism <NUM> supports the first suction cups <NUM> so that the first suction cups <NUM> rotate on an arc track about the central axis of rotation R that overlaps the imaginary line IL extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S.

In the box opening device illustrated in <FIG> of patent document <NUM> (<CIT>), the central axis of rotation of a first suction pad that holds one of two adjacent surfaces of a corrugated cardboard sheet and is rotated to transform the corrugated cardboard sheet into an opened state, is not aligned with the boundary line (fold portion) between the two adjacent surfaces of the corrugated cardboard sheet. With the box opening device illustrated in <FIG> of patent document <NUM> (<CIT>), the fold portion between two adjacent surfaces of the corrugated cardboard sheet is arranged near a second suction pad that is separate from the central axis of rotation of the first suction pad and holds a surface that differs from a surface held by the first suction pad that is rotated in order to transform the corrugated cardboard sheet to an opened state. With such a configuration, the surface held by the rotating first suction pad cannot smoothly turn about the fold portion with respect to the surface held by the second suction pad. In other words, in the box opening device disclosed by the patent document <NUM> (<CIT>), on the surface of the corrugated cardboard sheet held by the first suction pad, a force is also applied in a direction (radial direction with respect to the boundary line (fold portion) as the central axis) that is different from the direction (circumferential direction about the boundary line as the central axis) in which the force should be applied to open the corrugated cardboard sheet into a box. Therefore, with the box opening device of patent document <NUM> (<CIT>), according to the characteristics and state of the corrugated cardboard sheet, problems, such that the corrugated cardboard sheet (corrugated cardboard box) is damaged or deformed during the sheet is opened into a box, or opening the sheet into a box is failed due to release of the holding of the corrugated cardboard sheet at an unintended timing, may occur. These types of problems tend to occur particularly in cases, for example, in which the corrugated cardboard sheet is thin and its strength is relatively low, and in which recycled corrugated cardboard sheets are used.

In contrast, with the box opening device <NUM> according to the present embodiment, a force can be applied on the first side surface T1 of the corrugated cardboard sheet S held by the first suction cups <NUM>, solely in the direction (circumferential direction with respect to the fold portion X12 as the center axis) in which a force should be applied to open the sheet into a box. Therefore, the box opening device <NUM> according to the present embodiment can reliably open the corrugated cardboard sheet S into a box without damaging or deforming the corrugated cardboard sheet S regardless of the characteristics and state of the corrugated cardboard sheet S.

(<NUM>-<NUM>) With the box opening device <NUM> according to the abovementioned embodiment, the central axis of rotation R is immobile during rotation of the first suction cups <NUM>.

With the box opening device <NUM> according to the abovementioned embodiment, it is easy to apply a force on the first side surface T1 of the corrugated cardboard sheet S solely in the direction in which the force should be applied to open the corrugated cardboard sheet S into a box, and it is therefore easy to reliably open the corrugated cardboard sheet S into a box without damaging or deforming the corrugated cardboard sheet S regardless of the characteristics and state of the corrugated cardboard sheet S.

(<NUM>-<NUM>) With the box opening device <NUM> according to the abovementioned embodiment, the distance between the central axis of rotation R and the first suction cups <NUM> is constant during rotation of the first suction cups <NUM>. For example, during rotation of the first suction cup <NUM>, a distance between the central axis of rotation R and the center 21a (see <FIG>) of a circular first suction cup <NUM> as a representative point of the first suction cup <NUM> is constant.

(<NUM>-<NUM>) With the box opening device <NUM> according to the abovementioned embodiment, the link mechanism <NUM> is disposed within a positional range at which the boundary line A is present, in the extension direction of the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S that is opened by the first holding part movement mechanism <NUM>.

With the box opening device <NUM> according to the abovementioned embodiment, in the extension direction (vertical direction here) of the boundary line A of the corrugated cardboard sheet S that is opened into a box, the link mechanism <NUM> is disposed within a positional range (height position) at which the boundary line A is present. Therefore, the box opening device <NUM> (box-opening unit <NUM>) can be made more compact in the direction along which the boundary line A of the opened corrugated cardboard sheet S extends.

(<NUM>-<NUM>) With the box opening device <NUM> according to the abovementioned embodiment, the second holding part movement mechanism <NUM> that rotates the second suction cups <NUM> about the prescribed rotation axis P is provided.

With the box opening device <NUM> according to the abovementioned embodiment, the second suction cups <NUM> can also be rotated, and the second suction cups <NUM> can be moved with respect to the corrugated cardboard sheet S. More specifically, with the present box opening device <NUM>, the second suction cups <NUM> that are not contacting the corrugated cardboard sheet S can be rotated by the second holding part movement mechanism <NUM>, and moved to positions at which the second suction cups <NUM> can hold the second side surface T2 of the corrugated cardboard sheet S (positions at which the suction attachment surfaces 22b of the second suction cups <NUM> contact the second side surface T2). Therefore, with the box opening device <NUM> according to the abovementioned embodiment, the corrugated cardboard sheet S to be supplied to the box opening device <NUM> can be reliably held by the first suction cups <NUM> and the second suction cups <NUM>.

A box opening device <NUM> according to a second embodiment of the present invention is described below while referencing <FIG> and <FIG>. The box opening device <NUM> according to the second embodiment is the same as the box opening device <NUM> according to the first embodiment with the exception that a first holding part movement mechanism <NUM> is used in place of the first holding part movement mechanism <NUM> of the box-opening unit <NUM>. Therefore, with the exception of a description of the first holding part movement mechanism <NUM>, a description of the box opening device <NUM> according to the second embodiment is omitted.

<FIG> is a schematic front view that schematically depicts a state in which the box-opening unit <NUM> has received the folded corrugated cardboard sheet S supplied from the sheet supply unit <NUM>. In <FIG>, the first holding part movement mechanism <NUM> is schematically depicted. <FIG> is a schematic plan view that schematically depicts the first holding part movement mechanism <NUM>.

With the box opening device <NUM> of the first embodiment, the link mechanism <NUM> supports the first suction cups <NUM> so that the first suction cups <NUM> rotates on an arc around track about the central axis of rotation R that overlaps the imaginary line IL that extends along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S.

In contrast, the box opening device <NUM> of the second embodiment has a first holding part movement mechanism <NUM> in place of the first holding part movement mechanism <NUM> of the first embodiment. Similar to the second holding part movement mechanism <NUM> of the first embodiment, the first holding part movement mechanism <NUM> includes primarily an arm member <NUM>, a turning shaft <NUM> coupled to the arm member <NUM>, a bearing <NUM> that rotatably supports the turning shaft <NUM>, a link (not illustrated), and an arm drive unit (not illustrated) (see <FIG> and <FIG>). The arm member <NUM> and the turning shaft <NUM> may be integrally formed. The arm member <NUM>, the turning shaft <NUM>, and the bearing <NUM> configure a support member <NUM> (see <FIG>). Similar to the first embodiment, the first holding part movement mechanism <NUM> is attached to the holding part movement mechanism support part <NUM> of the movement mechanism <NUM> that is configured to be movable in the front-back direction, and is supported by the holding part movement mechanism support part <NUM>.

The bearing <NUM> rotatably supports the turning shaft <NUM> coupled to the arm member <NUM>, and thereby rotatably supports the arm member <NUM>. The central turning axis of the bearing <NUM>, or in other words, the central turning axis of the turning shaft <NUM> that is supported by the bearing <NUM>, is arranged on an imaginary line IL extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S to be opened by the first holding part movement mechanism <NUM>. In order to avoid contact with the corrugated cardboard sheet S that is opened by the first holding part movement mechanism <NUM>, the bearing <NUM> is arranged at a position that is higher than the upper end of the corrugated cardboard sheet S (upper end of the top lid side flaps F2 of the corrugated cardboard sheet S) (see <FIG>).

Driving of the arm member <NUM> by the arm drive unit is implemented in the same manner as the driving of the arm member <NUM> by the arm drive unit <NUM> in the second holding part movement mechanism <NUM> of the first embodiment, and therefore a description is omitted here.

The arm member <NUM> according to the present embodiment includes a first portion 131a extending horizontally from the turning shaft, a second portion 131b extending downward from the first portion 131a, and a third portion 131c extending horizontally from a lower end of the second portion 131b (see <FIG> and <FIG>). Two first suction cups <NUM> are attached to the horizontally extending third portion 131c of the arm member <NUM> along the longitudinal direction (see <FIG> and <FIG>). The shape of the arm member <NUM> is given as an example, and the shape is not limited thereto.

The arm member <NUM> rotates about the central turning axis of the turning shaft <NUM> that is rotatably supported by the bearing <NUM>, and thereby the first suction cups <NUM> attached to the third portion 131c of the arm member <NUM> rotate about a central axis of rotation R' that overlaps the central turning axis of the turning shaft <NUM> (see <FIG>). That is, in the box opening device <NUM> according to the second embodiment, the support member <NUM> of the first holding part movement mechanism <NUM> supports the first suction cups <NUM> so that the first suction cups <NUM> rotate on an arc track about the central axis of rotation R' that overlaps the imaginary line IL extending along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S. The central axis of rotation R' is immobile during rotation of the first suction cups <NUM>. Also, during rotation of the first suction cups <NUM>, the distance between the central axis of rotation R' and the first suction cup <NUM> (for example, the distance between the central axis of rotation R' and the center 21a of a circular first suction cup <NUM>) is constant.

The box opening device <NUM> of the second embodiment has the same characteristics as the characteristics (<NUM>-<NUM>) to (<NUM>-<NUM>) and (<NUM>-<NUM>) of the box opening device <NUM> of the first embodiment.

Furthermore, the box opening device <NUM> of the second embodiment also has following characteristics.

With the box opening device <NUM> according to the second embodiment, the support member <NUM> of the first holding part movement mechanism <NUM> includes the arm member <NUM> and the bearing <NUM>. The first suction cups <NUM> are attached to the arm member <NUM>. The bearing <NUM> defines a central turning axis disposed on the imaginary line, and rotatably supports the arm member <NUM>. The central turning axis of the bearing <NUM> is disposed on the imaginary line IL that extends along the boundary line A between the first side surface T1 and the second side surface T2 of the corrugated cardboard sheet S that is opened by the first holding part movement mechanism <NUM>.

By adopting such a configuration, it is easy to apply a force on the first surface T1 of the corrugated cardboard sheet S solely in the direction in which the force should be applied to open the sheet into a box. In other words, a configuration such as that described above makes it easier to apply only a force that is necessary for turning the first side surface T1 around the first fold portion X12 of the corrugated cardboard sheet S on the first side surface T1. Therefore, it is easy to reliably open the corrugated cardboard sheet S into a box without damaging or deforming the corrugated cardboard sheet S.

With the box opening device <NUM> according to the second embodiment, as described above, the bearing <NUM> of the support member <NUM> of the first holding part movement mechanism <NUM> is arranged at a position that is higher than the upper end of the corrugated cardboard sheet S to be opened, and therefore the height of the box-opening unit <NUM> of the box opening device <NUM> tends to increase. Therefore, from the perspective of compactness of the box-opening unit <NUM>, use of the link mechanism <NUM> as the support member, as with the first embodiment, is preferable.

In the abovementioned embodiments, after the corrugated cardboard sheet S is transformed to an opened state by the first holding part movement mechanism <NUM>, <NUM>, the opened corrugated cardboard sheet S (tubular corrugated cardboard box TB) is moved to the bottom lid forming unit <NUM> by the movement mechanism <NUM>, but such an arrangement is not provided by way of limitation to the present invention. For example, the box opening device <NUM> may be configured so that while the corrugated cardboard sheet S is being opened by the first holding part movement mechanism <NUM>, <NUM>, the movement mechanism <NUM> simultaneously moves the holding part movement mechanism support part <NUM> to thereby move the corrugated cardboard sheet S to the bottom lid forming unit <NUM> side.

Claim 1:
A box opening device (<NUM>) comprising:
a plurality of first holding parts (<NUM>) that are configured to hold a first surface (T1), which is one of two adjacent surfaces of a folded corrugated cardboard sheet (S);
a second holding part (<NUM>) that is configured to hold a second surface (T2), which is the other of the two adjacent surfaces of the corrugated cardboard sheet (S); and
a first holding part movement mechanism (<NUM>) which is configured to change a position of the first holding part (<NUM>) with respect to the second holding part (<NUM>) and thereby transforms the corrugated cardboard sheet (S) into an opened state;
wherein the first holding part movement mechanism (<NUM>) has a link mechanism (<NUM>) as a support member that supports the first holding part (<NUM>) and a link mechanism drive unit (<NUM>) connected to the link mechanism (<NUM>) and configured to drive the link mechanism to move the first holding part (<NUM>) by rotating the first holding part (<NUM>),
wherein the link mechanism includes a plurality of links (<NUM>), each of the links (<NUM>) being connected to another link through a joint, the plurality of links further including a first holding part attachment link (32a) that supports the plurality of first holding parts (<NUM>), and a driven link (32b) to which link mechanism drive unit (<NUM>) is connected,
wherein the first holding part attachment link (32a) extends in a first direction and the plurality of first holding parts (<NUM>) are arranged on the first holding part attachment link (32a) along the first direction, and
wherein the first holding part attachment link (32a) is configured to revolve while maintaining a parallel relationship between the first direction of the first holding part attachment link (32a) and the first surface;
characterized in that the first holding part (<NUM>) rotates on an arc track about a central axis of rotation (R, R') that overlaps an imaginary line (IL) extending along a boundary line between the first surface (T1) and the second surface (T2),
whereby a force only in the circumferential direction about the central axis (R, R') is applied to the first surface (T1).