JP7373464B2 - vacuum suction car - Google Patents

Description

The present invention relates to a vacuum suction wheel that is installed in a discharge section of a sheet-fed printing press and that reduces the conveyance speed of sheets.

A vacuum suction wheel is described in Patent Document 1, for example. In the vacuum suction wheel described in Patent Document 1, a suction outer tube (the "rotating suction shell" in Patent Document 1) that is long in the width direction of the sheet that is conveyed to the discharge section has a plurality of holes. have. The outer suction tube is a circular tube. The outer suction tube is connected to a vacuum pump, and by driving the vacuum pump, suction force can be generated in the plurality of holes. The discharge section is provided with a paper discharge gripper that grips and conveys the sheets. By applying driving force to the suction outer tube and rotating it so that the speed in the tangential direction is lower than the moving speed of the paper discharge gripper, the sheets released from the paper discharge gripper are sucked into the suction outer tube. (Specifically, the plurality of holes that the outer suction tube has) performs suction, thereby making it possible to reduce the sheet conveyance speed, that is, the paper ejection speed.

Patent No. 3332684

However, since this conventional vacuum suction wheel is shaped like a circular tube, its outer peripheral surface is a curved surface with a constant curvature. On the other hand, the surface of the sheet is flat. For this reason, since the curved surface (vacuum suction wheel) comes into contact with the flat surface (sheet), the two can only be in close contact with each other in a roughly linear manner, making it difficult to perform effective suction. It was difficult to decelerate the seat. This may cause sheet ejection failure.

In particular, when a thick sheet such as cardboard is used, the weight of the sheet is greater than that of a thin sheet, and the surface hardly deforms along the outer circumferential surface of the vacuum suction wheel. It was even more difficult to do. When such a thick sheet is used, for example, the sheet ejection speed has been set to a low speed, resulting in a problem of reduced printing efficiency.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a vacuum suction wheel capable of stably discharging sheets at a discharging section.

The vacuum suction wheel according to the present invention is installed in a discharge section of a sheet-fed printing press, and suctions a sheet conveyed to the discharge section with its outer peripheral surface while rotating along the conveyance direction. , in the vacuum suction vehicle for reducing the conveyance speed of the sheet, the suction inner tube is a straight tube fixed in the discharge section so that the axial direction is perpendicular to the conveyance direction, and is capable of creating a negative pressure in the internal space; It is a straight pipe located outside the diameter of the inner suction pipe, and includes an outer suction pipe that rotates in the circumferential direction with respect to the inner suction pipe, and the outer peripheral part of the outer suction pipe has a plurality of flat parts that rotate in the circumferential direction. Each of the plurality of plane parts is a plane perpendicular to the radial direction, and the radial dimension is smaller than that of the part sandwiched between the plane parts in the circumferential direction. each of the plurality of plane parts has a plurality of suction holes that are opened so as not to contact the circumferential edge of the plane, and each of the plurality of plane parts has a plurality of suction holes that are open to the inner space of the suction inner tube and that are in communication with the inner space of the inner suction tube. This is a vacuum suction wheel characterized by having a suction hole.

According to the above configuration, since the flat part contacts the sheet in a flat manner, it is easier to decelerate the sheet compared to a configuration in which a curved surface (outer suction tube) and a flat surface (sheet) contact each other. .

Further, the plane may be formed continuously in the axial direction.

According to the above configuration, since the plane continuous in the axial direction contacts the sheet uniformly, the sheet can be effectively sucked.

Further, the outer circumferential portion of the outer suction tube may include the flat portion and the circumferential surface portion alternately provided in the circumferential direction, and the circumferential surface portion may have a curved surface having a constant radius dimension. good.

According to the above configuration, the outer suction tube can be easily obtained by, for example, chamfering the circular tube that is the material.

According to the present invention, since the flat part of the suction outer tube contacts the sheet in a flat manner, compared to a structure in which a curved surface (suction outer tube) and a flat surface (sheet) contact, the sheet is It is easy to decelerate by bringing the vehicle into close contact with the vehicle. Therefore, the sheet can be stably discharged from the discharge section.

1 is a diagram schematically showing a configuration around a discharge section of a sheet-fed printing press equipped with a vacuum suction wheel according to an embodiment of the present invention. FIG. 3 is a perspective view showing the vacuum suction wheel. FIG. 3 is a radially cross-sectional view showing the vacuum suction wheel. FIG. 3 is a side view showing an outer suction tube of the vacuum suction wheel. (a) is a sectional view taken along the line VV in FIG. 4, and (b) is an enlarged view of the main part of (a). It is a side view which shows the suction outer tube of the vacuum suction wheel based on other embodiment of this invention. 7 is a sectional view taken along the line VII-VII in FIG. 6. FIG. FIG. 7 is a sectional view taken along the line VIII-VIII in FIG. 6;

Hereinafter, vacuum suction wheels 3 according to two embodiments of the present invention will be described with reference to the respective drawings.

As shown in FIG. 1, the vacuum suction wheel 3 of this embodiment is provided in a discharge section (paper discharge section) 2 of a sheet-fed printing press 1, like the conventional one. The function is to reduce the conveyance speed of the sheet S by rotating the sheet S conveyed to the discharge section 2 with the outer circumferential surface while rotating along the conveyance direction. has. This vacuum suction wheel 3 constitutes a part of a vacuum suction device that reduces the conveyance speed of the sheet S in the discharge section 2.

The vacuum suction wheel 3 is configured to move the sheet discharge grippers 21 (in FIG. 1, each of the plurality of sheet discharge grippers 21 provided on the sheet discharge chain 22 is indicated by a circle), which transports the sheets S by sandwiching them in the discharge section 2. (Only the movement trajectory is shown schematically). The paper discharge gripper 21 releases the sheet S on the front side (downstream side) of the vacuum suction wheel 3 in the conveying direction. Note that the release position of the sheet S is adjustable. The released sheet S moves in the transport direction due to inertia and is lowered by a downward airflow generated by a fan (not shown) provided in the discharge section 2. During this movement due to inertia, the sheet S is sucked by the vacuum suction wheel 3 and decelerated. The front edge of the decelerated sheet S in the conveyance direction hits a front guide 23 provided in the discharge section 2, and the rear edge in the conveyance direction is guided by a back guide 24 provided in the discharge section 2. Both edges in the width direction are guided by side guides (not shown) provided in the discharge section 2, so that the paper stops at a fixed position and is stacked vertically in an orderly manner on the pallet P prepared in the discharge section 2. It will be done.

The vacuum suction wheel 3 has an appearance shown in FIG. 2, and includes an inner suction tube 31 and an outer suction tube 32, as shown in FIG. The suction inner tube 31 is a straight tube that is provided so that its axial direction is perpendicular to the conveyance direction of the sheets S in the discharge section 2 and is fixed in the vacuum suction wheel 3 . The outer suction tube 32 is a straight tube located outside the inner suction tube 31 and covers the inner suction tube 31, and is provided to rotate in the circumferential direction with respect to the inner suction tube 31. The outer suction tube 32 is configured as a straight tube that is long in the width direction of the sheet S, that is, in a direction orthogonal to the conveying direction of the sheet S. The inner suction tube 31 functions as a support shaft that rotatably supports the outer suction tube 32. Both ends of the suction inner tube 31 are connected to a suction mechanism 4 that constitutes a part of a vacuum suction device. The suction mechanism 4 is provided at both ends of the vacuum suction wheel 3. The suction mechanism 4 is connected to a vacuum pump (not shown), and by driving the vacuum pump, the internal space 31S of the suction inner tube 31 can be made to have a negative pressure via the suction mechanism 4.

The suction inner tube 31 has a plurality of long holes 311...311 formed along the axial direction. Each long hole 311 passes through the suction inner tube 31 in the radial direction. The suction inner tube 31 is fixed to the vacuum suction wheel 3 so that the plurality of elongated holes 311...311 are located on the upper side. Note that the fixed position of the suction inner tube 31 in the vacuum suction wheel 3 can be changed in the circumferential direction. The formation positions of the plurality of long holes 311...311 in the axial direction match the formation positions of the plurality of suction holes 323...323 formed in the outer suction tube 32. As a result, as the outer suction tube 32 rotates, the plurality of suction holes 323 . By communicating with the internal space 31S of 31, the outer suction tube 32 can suck the sheet S.

The outer suction tube 32 rotates so that the speed in the tangential direction (horizontal direction in this embodiment) is lower than the speed of movement of the paper discharge gripper 21 in the movement direction 21M (see FIG. 1). In this embodiment, a gear 324 is provided at one end of the outer suction tube 32. On the other hand, the suction mechanism 4 is connected to a motor (not shown), and the driving force of the motor is transmitted to the suction outer tube 32 via the gear 324, so that when viewed from the axial direction in FIG. The suction outer tube 32 rotates counterclockwise.

As shown in FIG. 4, a plurality of flat parts 321...321 are provided intermittently in the circumferential direction of the outer suction tube 32 on the outer circumference of the outer suction tube 32. In this embodiment, each plane portion 321 is provided at 20 locations. As shown in FIGS. 5(a) and 5(b), flat portions 321 and circumferential surface portions 322 are alternately provided on the outer peripheral portion of the outer suction tube 32 in the circumferential direction of the outer suction tube 32. The plane portion 321 and the circumferential surface portion 322 are provided at equal angular intervals in the circumferential direction. The respective quantities and circumferential dimensions of the plane portion 321 and the circumferential surface portion 322 can be determined as appropriate. The circumferential surface portion 322 has a curved surface 3221 with a constant radius dimension, that is, a constant curvature.

Each plane part 321 is a plane perpendicular to the radial direction of the outer suction tube 32, and compared to the part sandwiched between the two plane parts 321, 321 in the circumferential direction (the circumferential surface part 322 in this embodiment), It has a flat surface 3211 formed with a small radial dimension, which is the radial distance from the center. In this embodiment, the forming ranges of each plane part 321 and plane 3211 are the same, but as in the second embodiment (reference example) described later, each plane part 321 (groove-shaped part) and plane 3211 (groove) are formed in the same range. The formation ranges of the bottom surfaces of the shaped portions do not need to match. In the cross-sectional shape cut in the radial direction, the plane 3211 is perpendicular to the radial virtual line passing through the center of the outer suction tube 32. In other words, the virtual line coincides with the normal to the plane 3211. Moreover, the plane 3211 is formed with a uniform width in the circumferential direction with this imaginary line as a reference. That is, the virtual line passes through the center of the plane 3211 in the width direction. In the cross-sectional shape cut in the radial direction, the radial dimension, which is the radial distance of the flat surface 3211 from the center of the suction outer tube 32, is smaller than the radial dimension of the curved surface 3221 of the circumferential surface portion 322, that is, the radius. Small except for the edges. The boundary between the plane part 321 and the circumferential surface part 322 (the circumferential edge of each part) has the same radial dimension, and the parts 321 and 322 are connected without any difference in level. Note that the boundary may also have a gently rounded shape.

In each plane portion 321, the plane 3211 is formed continuously in the axial direction. By forming the plane 3211 in this way, the plane 3211 (one plane 3211) that is continuous in the axial direction comes into uniform contact with the sheet S. That is, the flat portion 321 contacts the sheet S in a flat manner. For this reason, compared to the conventional configuration in which a curved surface (outer suction tube) and a flat surface (sheet of paper) come into contact, the contact between each suction hole 323 and the surface of sheet S or printed surface during suction is smaller. Since air leakage is less likely to occur between the two and the two can be brought into close contact, the suction force is less likely to be lost and the sheet S can be suctioned effectively. Therefore, since the sheets S are easily decelerated by suction, the stack of sheets S is not disturbed, and the sheets can be stably discharged from the discharge section 2. Furthermore, it is possible to suppress the occurrence of scratches or dents on the edges of the sheet S due to the sheet S colliding forcefully with the front guide 23.

Here, the circumferential surface portion 322 corresponds to the portion that was not chamfered when the flat surface portion 321 was formed by chamfering the outer peripheral surface of the circular tube that is the material of the outer suction tube 32, for example by cutting. do. As described above, the suction outer tube 32 in which the flat portions 321 and the circumferential surface portions 322 are alternately provided can be easily obtained by chamfering a circular tube or the like. Therefore, for example, the flat portion 321 can be formed by cutting the outer circumferential surface of the circular tube, which is a common process. Note that the flat portion 321 and the circumferential surface portion 322 are buffed to prevent them from getting caught on the sheet S.

Each plane portion 321 in this embodiment is longer in the axial direction than the maximum width dimension of the sheet S conveyed to the discharge section 2. Further, each flat portion 321 of this embodiment is provided over the entire length of the exposed portion of the discharge portion 2 of the outer suction tube 32, as shown in FIG. Each plane portion 321 has a plurality of suction holes 323 . These plurality of suction holes 323...323 can communicate with the internal space 31S of the inner suction tube 31. Each suction hole 323 has a perfect circular shape when viewed in the radial direction, and is a through hole that penetrates the outer suction tube 32 in the radial direction. However, the shape of each suction hole 323 is not limited to this. Furthermore, in this embodiment, five suction holes 323 arranged in the axial direction are arranged as one set, and each set is arranged at a predetermined distance in the axial direction. is not particularly limited. However, setting the distance between both ends of the plurality of suction holes 323 . desirable for this reason.

As mentioned above, the sheet S released from the paper ejection gripper 21 and moving in the ejection section 2 by inertia is sucked into the plurality of suction holes 323 . . . 323 of the outer suction tube 32. It is held by suction on the outer suction tube 32. As a result, the sheet S is decelerated to the circumferential speed of the rotating outer suction tube 32 (specifically, the tangential speed of the outer suction tube 32). In this embodiment, the outer suction tube 32 attracts the sheet S on the rear side (upstream side) of the sheet S in the conveyance direction (vertical direction of the sheet S) from approximately the center in the conveyance direction.

As shown in FIG. 5(b), the suction hole 323 has an enlarged portion 3231 whose diameter is enlarged at a radially outer position. The connection part (opening edge, ridgeline part) of the suction hole 323 (specifically, the enlarged part 3231) to the plane 3211 has a curved surface 3232, which is not clearly shown, and has a fine rounded shape. There is. In this way, since the part that contacts the sheet S has no corners (is not sharp) and has a rounded shape, even if the suction outer tube 32 comes into contact with the sheet S during suction, the sheet The surface of the sheet S and the printed surface formed on the sheet S are not easily damaged.

Next, a second embodiment as a reference example will be described. In addition, the following description mainly explains the different form from 1st Embodiment. In the second embodiment, as shown in FIGS. 6 to 8, the flat portion 321 has a groove shape along the axial direction, and the flat surface 3211 of the flat portion 321 is formed at a recessed position on the inside in the radial direction. Therefore, unlike the first embodiment, each plane 3211 does not directly contact the surface of the sheet S, but the circumferential edge of each plane portion 321 contacts. However, even in such a case, since the contact state at the circumferential edge of each flat portion 321 is flat, the effect of "suctioning the sheet S on a flat surface" is achieved as in the first embodiment. is played.

In the second embodiment, since the flat portion 321 is groove-shaped, negative pressure can be uniformly applied to the recessed flat portion 321. Therefore, compared to the first embodiment in which only each suction hole 323 is under negative pressure, the sheet S can be suctioned over a wider area. Also, depending on the size of the sheet S, even if there is a portion of the flat portion 321 that does not overlap the sheet S, suction is applied from that portion to a portion of the flat portion 321 that overlaps the sheet S. An accompanying air current is generated. Since negative pressure is also generated by this airflow, in addition to the direct suction force from the suction hole 323, a suction force is generated between the sheet S and the portion of the flat portion 321 that overlaps the sheet S. be caused to occur.

In this second embodiment as well, the sheets S can be suctioned more effectively than in the conventional configuration in which a curved surface (outer suction tube) and a flat surface (sheets) are in contact with each other. Therefore, since the sheet S can be easily decelerated, the sheet can be stably ejected from the ejecting section 2.

Although the vacuum suction wheel 3 according to two embodiments of the present invention has been described above, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention. It is possible.

For example, the circumferential surface portion 322 may not be provided, and the space between the two planar portions 321, 321 may be formed in a different form. For example, a space between the planes 3211 (plane parts 321 in the embodiment described above) having the suction holes 323 may be a plane having no suction holes 323 (a different part from the plane part 321 in the embodiment).

Furthermore, for example, the outer suction tubes 32 are not configured as a single straight tube extending in a direction perpendicular to the conveyance direction of the sheets S, but are arranged in parallel in a direction perpendicular to the conveyance direction of the sheets S. It may be configured as a plurality of straight pipes.

DESCRIPTION OF SYMBOLS 1... Sheet-fed printing machine, 2... Discharge part, 3... Vacuum suction wheel, 4... Suction mechanism, 21... Paper discharge gripper, 21M... Moving direction of paper discharge gripper, 22... Paper discharge chain, 23... Front guide, 24 ...Back guide, 31...Suction inner tube, 31S...Inner space, 32...Suction outer tube, 311...Long hole, 321...Plane part, 322...Circumferential surface part, 323...Suction hole, 324...Gear, 3211...Plane, 3221...Curved surface (circumferential surface part), 3231...Enlarged part, 3232...Curved surface (suction hole), P...Pallet, S...Single-leaf sheet, sheet paper

Claims (3)

Provided at the discharge section of a sheet-fed printing press, the sheet conveyance speed is reduced by suctioning the sheet conveyed to the discharge section with the outer peripheral surface while rotating along the conveyance direction. In the vacuum suction vehicle,
a straight pipe fixed in the discharge part so that its axial direction is perpendicular to the conveyance direction, and a suction inner pipe that can create negative pressure in the internal space; and a straight pipe located outside the diameter of the suction inner pipe, a suction outer tube that rotates in a circumferential direction with respect to the inner suction tube,
A plurality of flat parts are provided intermittently in the circumferential direction on the outer peripheral part of the outer suction tube,
Each of the plurality of flat parts is not in the shape of a groove , but is a flat face perpendicular to the radial direction, and is sandwiched in the circumferential direction by the flat parts that come into planar contact with the sheet during suction. It has a flat surface with a smaller radius dimension than the other parts,
Each of the plurality of plane parts has a plurality of suction holes that are opened so as not to touch the circumferential edge of the plane, and that can communicate with the internal space of the inner suction tube. A vacuum suction vehicle comprising: The vacuum suction wheel according to claim 1, wherein the plane is formed continuously in the axial direction. The outer peripheral portion of the outer suction tube is provided with the flat portion and the circumferential surface portion alternately in the circumferential direction,
The vacuum suction wheel according to claim 1 or 2, wherein the circumferential surface portion has a curved surface with a constant radial dimension.