CN113396061B

CN113396061B - Printing device

Info

Publication number: CN113396061B
Application number: CN202080012266.1A
Authority: CN
Inventors: 一之濑孝一; 土肥克己; 西口真一郎; 山城和俊
Original assignee: Toshin Kogyo Co Ltd
Current assignee: Toshin Kogyo Co Ltd
Priority date: 2019-02-19
Filing date: 2020-02-07
Publication date: 2022-11-25
Anticipated expiration: 2040-02-07
Also published as: EP3928984A4; EP3928984A1; JP7345900B2; CN113396061A; WO2020170868A1; JPWO2020170868A1

Abstract

The invention provides a printing device, which has a function of restraining the extension and contraction of a conveying belt when the conveying belt performs intermittent feeding action. A printing device (10) is provided with: a conveyor belt (11) which supports the printing object from below and conveys the printing object in a horizontal direction; a belt driving mechanism (12) for causing the conveyor belt (11) to perform an intermittent feeding operation; a printing mechanism (13) which is arranged on the traveling path of the conveyor belt (11) and prints on the object to be printed; a support table (14) that supports the conveyor belt (11) from below when printing is performed by the printing mechanism (13); and a belt feeding auxiliary mechanism for assisting the intermittent feeding operation of the conveyor belt (11) by the belt driving mechanism (12).

Description

Printing device

Technical Field

The present invention relates to a printing apparatus, and more particularly, to a printing apparatus having a function of assisting an intermittent feeding operation of a conveyor belt that conveys a printing object.

Background

Conventionally, a printing apparatus using a screen printing plate is provided, for example, as shown in patent document 1. The printing apparatus described in patent document 1 includes: a conveyer belt, the surface of which is stuck with cloth to convey the cloth; a driving roller that drives the conveying belt; a screen plate positioned on a surface of the cloth and formed with a printed pattern; a printing unit having a squeegee; and a support table for supporting the conveyor belt from the lower surface when the printing unit prints the fabric. The screen plate is formed with a plate making area. The platemaking area has an area for shielding ink and a hole through which the ink passes. The ink is made to flow on the screen plate, and the squeegee is moved on the surface of the screen plate in a state where the screen plate is pressed against the cloth, so that the ink passes through the holes of the screen plate to perform printing on the cloth under the screen plate. When the operation of the squeegee is completed, the cloth is intermittently fed by the driving roller and the conveyor belt, and the surface area of the cloth to be printed next is positioned below the screen plate, and the surface of the cloth is sequentially printed.

As a printing apparatus, for example, a printing apparatus using an ink jet mechanism as shown in patent document 2 is known. The printing device has a plurality of nozzles accommodated in a print head, and each nozzle ejects ink of a plurality of colors. The conveyer belt intermittently conveys the cloth at intervals of the printing pitch of the printing head. Each time the cloth is intermittently conveyed, the printing head is moved in a direction (width direction of the cloth) orthogonal to the conveyance direction of the cloth, and the ink is ejected from the nozzles to print a pattern on the surface of the cloth.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-044330

Patent document 2: japanese patent No. 5116542

Disclosure of Invention

Problems to be solved by the invention

In a printing apparatus using a screen plate or an ink jet mechanism, the intermittent feeding accuracy of a cloth is poor, and a conveyance error may occur. When the fabric is conveyed by a distance shorter than the length of the printing pitch, a large overlap may occur between a portion printed first and a portion printed later, resulting in color unevenness. Further, if the cloth is conveyed by a distance longer than the length of the printing pitch, a gap may be left between a portion printed first and a portion printed later. If there is a conveyance error in this way, the fabric cannot be printed with high precision. Therefore, it is desirable to reduce the conveying error as much as possible and improve the conveying accuracy.

One of the causes of the conveyance error is the expansion and contraction of the conveyor belt itself. The transport belt of the printing apparatus is generally an endless belt which is stretched between a drive roller and a driven roller provided on the upstream side and the downstream side in the transport direction of the fabric. The drive roller is connected to a drive source such as a servo motor. The drive roller is rotated by intermittently operating the drive source, thereby intermittently feeding the conveyor belt. Even when the driving of the driving roller is not error-free, if the conveying belt itself expands or contracts, the cloth conveying position is deviated from a desired position, and as a result, a conveying error occurs. In particular, the center portion of the conveyor belt in the conveying direction is not supported by the driving roller or the driven roller as in the case of the upstream or downstream end portions, and is likely to expand or contract. Further, when the lower surface of the central portion of the conveyor belt is brought into contact with the support base to be supported by the support base and the conveyor belt is intermittently moved, the central portion of the conveyor belt is stretched by a frictional force between the lower surface of the conveyor belt and the upper surface of the support base. Depending on the material of the conveyor belt, an error of about ± 0.3mm may occur.

The present invention has been made in view of the above problems, and an object thereof is to provide a printing apparatus having a function of suppressing expansion and contraction of a conveyor belt when the conveyor belt performs an intermittent feeding operation.

Means for solving the problems

The printing apparatus according to the present invention includes: a conveyor belt that supports the printing object from below and conveys the printing object in a horizontal direction; a belt driving mechanism for intermittently feeding the conveyor belt; a printing mechanism which is arranged on the traveling path of the conveyor belt and prints on the printing object; a support table that supports the conveyor belt from below when the printing mechanism performs printing; and a belt feeding assist mechanism that assists the intermittent feeding operation of the conveyor belt by the belt drive mechanism.

According to the above configuration, since the intermittent feeding operation of the conveyor belt is assisted by the belt feeding assisting mechanism, the extension and contraction of the conveyor belt can be suppressed, and the fabric can be printed with high accuracy.

In one embodiment, the belt feed assist mechanism assists the intermittent feeding operation of the conveying belt every time the intermittent feeding operation of the conveying belt is performed by the belt driving mechanism.

The belt feed assisting mechanism may be a gap forming mechanism that forms a gap between the lower surface of the conveyor belt and the support table.

The tape feed assist mechanism may further have: an air hole formed in the support table; and an air supply mechanism that supplies air fed from the air holes toward the lower surface of the conveyor belt.

In another embodiment, the belt feed assist mechanism is an up-pushing mechanism that pushes up the conveyor belt to move the conveyor belt away from the support table.

In another embodiment of the above, the push-up mechanism may further include: a push-up member that abuts against a lower surface of the conveyor belt and pushes up the conveyor belt; and an elevating mechanism that elevates the push-up member so that an upper end of the push-up member is exposed to and exposed from an upper surface of the support table.

The push-up member may also be a push-up roller that rotates with the movement of the conveyor belt.

Effects of the invention

According to the present invention, since the intermittent feeding operation of the conveyor belt is assisted by the belt feeding assisting mechanism, the extension and contraction of the conveyor belt can be suppressed, and the conveying error of the fabric can be reduced, thereby performing high-precision printing.

Drawings

Fig. 1 is a side view showing an overall schematic configuration of a printing apparatus according to a first embodiment of the present invention.

Fig. 2 is a plan view schematically showing a structure in which a main part of the conveyor belt and the support table is cut away.

Fig. 3 is an enlarged perspective view of a main part of the conveyor belt and the support table, with a part of the conveyor belt and the support table being cut away.

Fig. 4 is an enlarged sectional view of a main part of the printing apparatus.

Fig. 5 is a side view showing a schematic configuration of the entire printing apparatus according to the second embodiment.

Fig. 6 is a plan view showing a schematic configuration of the printing apparatus.

Fig. 7 is a perspective view of the push-up mechanism.

Fig. 8 is a side view showing another example of the push-up mechanism.

Fig. 9 is a side view showing another example of the push-up mechanism.

Fig. 10 is a plan view showing another example of the overall configuration of the printing apparatus.

Detailed Description

Embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 to 4 show a printing apparatus 10 according to a first embodiment of the present invention. The printing apparatus 10 includes: a conveyor belt 11 that supports the printing object from below and conveys the printing object in a horizontal direction; a belt driving mechanism 12 for intermittently feeding the conveyor belt 11; a printing mechanism 13 disposed on the traveling path of the conveyor belt 11 and configured to print an object to be printed; a support table 14 that supports the conveyor belt 11 from below when printing is performed by the printing mechanism 13; and a belt feeding assisting mechanism 20 for assisting the intermittent feeding operation of the conveyor belt 11 every time the intermittent feeding operation of the conveyor belt 11 is performed by the belt driving mechanism 12. The intermittent feeding operation includes an operation of conveying the conveyor belt 11 by a predetermined distance and a stop operation, and the conveying operation and the stop operation are repeated.

The printing object is, for example, a fabric C. The material of the fabric C is not particularly limited, and various fabrics made of natural fibers such as cotton and silk, artificial fibers such as polyester, rayon, and acetate fibers, and the like can be used. In fig. 1, the fabric is conveyed from the left side to the right side, the direction in which the fabric is conveyed is referred to as the conveying direction, and the direction perpendicular to the conveying direction is referred to as the width direction of the fabric.

The belt driving mechanism 12 includes:

drive rollers

12a, 12a provided on the upstream side and the downstream side in the conveying direction and rotationally driven; and a drive source (not shown) such as a servo motor coupled to the rotation shafts of the

drive rollers

12a, 12a. An endless conveyor belt 11 is stretched between the drive rollers 12a, and the

drive rollers

12a, 12a rotate by a drive source to intermittently feed the conveyor belt 11. Further, a driven roller may be used instead of one driving roller 12a.

The conveyor belt 11 is made of an elastic body such as urethane rubber, and an adhesive layer (not shown) is provided on the upper surface thereof to support the fabric C. The long cloth C wound in a roll shape is disposed on the upstream side of the conveyor belt 11, is pulled out by the pull-out roller 15a, and is stuck to the conveyor belt 11 by the sticking roller 15 b. The fabric C conveyed by the conveyor 11 is printed on the surface thereof, and then wound around a winding roller 15C on the downstream side. The surface of the conveyor belt 11 is cleaned by a cleaning device (not shown) provided on the way from the downstream-side drive roller 12a to the upstream-side drive roller 12a, and an adhesive layer is formed on the surface by a glue application device (not shown).

The printing mechanism 13 is provided above the fabric C attached to the conveyor belt 11, for example, for screen printing, and is provided on a holder 16 (fig. 2) of the printing apparatus 10 so as to face the support table 14 up and down. The printing mechanism 13 includes a printing plate 13a, a printing unit 13b, and a moving mechanism (not shown) for moving the printing plate 13a and the printing unit 13 b. The printing plate 13a is provided with a screen (not shown) inside a rectangular frame. The screen is provided with minute holes corresponding to the pattern to be printed. The printing unit 13b is a unit in which a pair of squeegee carriers reciprocate in the width direction of the fabric C along two guide frames extending in the width direction of the fabric C across the printing plate 13a, and the pressure of the squeegees supported by the squeegee carriers is applied to the screen of the printing plate 13a during the forward movement and the backward movement of the squeegees. In the printing by the printing mechanism 13, first, the screen of the printing plate 13a presses the surface of the fabric C, and then, the squeegee moves on the screen. Thus, the ink on the screen reaches the cloth C through the fine holes of the screen, and a desired pattern is printed on the cloth C. The printing mechanisms 13 are provided according to the number of colors of ink used, and for example, ten printing mechanisms 13 are arranged along the conveying direction in the case of using ten colors of ink. In fig. 1, for convenience of explanation, only one printing mechanism 13 is shown. The printing mechanism 13 is not limited to the configuration of the present embodiment, and may be, for example, an inkjet printing mechanism.

The support table 14 is provided below the outgoing conveyor belt 11, and is supported by a carriage 16 of the printing apparatus 10. As shown in fig. 2 to 4, the support table 14 has a plurality of air holes 21 penetrating in the vertical direction. A duct 22 having an open upper surface and communicating with the air hole 21 is attached to the lower surface of the support table 14, and the duct 22 is connected to an air supply mechanism 23, for example, a blower, via an air pipe 24. The air supplied from the air supply mechanism 23 is blown out of the air holes 21 through the duct 22 and is fed toward the lower surface of the conveyor belt 11. The load of the conveyor belt 11 on the support table 14 is supported by this air. The amount of air blown out and the speed of air ejected from each air hole 21 per predetermined time can be adjusted. By adjusting these, the conveyor belt 11 is floated from the support base 14, and a gap is formed between the lower surface of the conveyor belt 11 and the support base 14, so that the upper surface of the support base 14 is not in contact with the lower surface of the conveyor belt 11. In fig. 2 and 3, the printing mechanism, the cloth, and the belt driving mechanism are not shown.

The air holes 21, the air tube 24, and the air supply mechanism 23 provided in the support table 14 constitute the belt feed assisting mechanism 20, and in the present embodiment, the belt feed assisting mechanism 20 is a gap forming mechanism that forms a gap between the lower surface of the conveyor belt 11 and the support table 14. However, the tape feed assisting mechanism 20 is not limited to a mechanism for forming a gap, and may be a state in which the conveyor belt 11 does not float from the support base 14 and the conveyor belt 11 comes into contact with the support base 14, depending on the amount of air fed per predetermined time and the speed of air ejected from each air hole 21.

In the present embodiment, nine support plates 14A to 14I are continuously arranged in the conveying direction on the support table 14, and the support plates have a length of 1200mm in the conveying direction, a length of 2400mm in a direction (width direction of the fabric C) orthogonal to the conveying direction, and a thickness of 3mm. However, the support base 14 is not limited to this configuration, and may be formed of a single flat plate, and the number and size of the support plates may be arbitrary. In the present embodiment, the diameter of each air hole 21 is set to about 2mm.

In the present embodiment, as shown in fig. 1 to 3, a total of four ducts 22 are attached to the

support plates

14B, 14E, and 14H of the second, fifth, and eighth sheets in the width direction of the fabric C, and the four ducts 22 are connected to one air supply mechanism 23 via air tubes 24. That is, in the present embodiment, the support table 14 is provided with three sets of one air supply mechanism 23 and four ducts 22 in total. Seven air holes 21 are provided in the conveying direction in the regions of the

support plates

14B, 14E, and 14H corresponding to the ducts 22, and four air holes 21 are provided in the width direction of the fabric C. That is, a total of 48 air holes 21 are provided in each of the

support plates

14B, 14E, and 14H.

The support plates forming the air holes 21, the number of the air holes 21, and the provided area are not limited to the present embodiment, and may be appropriately selected as long as the load of the conveyor belt 11 positioned on the support table 14 can be supported to reduce the frictional force between the conveyor belt 11 and the support table 14. The air holes 21 may be formed in any region of the support table 14. Further, if air can be supplied to the air holes 21, the size and number of the ducts 22, the number of the air tubes 24, and the number of the air supply mechanisms 23 are not limited, and for example, one duct 22 may be provided for each of the

support plates

14B, 14E, and 14H. Further, each of the plurality of ducts 22 may be provided with an air supply mechanism 23. In this case, the amount of air supplied from the air hole 22 communicating with the duct 22 can be adjusted for each air supply mechanism 23.

In the present embodiment, the printing mechanism 13 is provided above the first, third, fourth, sixth, seventh, and

ninth support plates

14A, 14C, 14D, 14F, 14G, and 14I in which the air holes 21 are not provided, but the printing mechanism 13 may be provided above the

support plates

14B, 14E, and 14H if the diameter of the air holes 21 is large enough not to affect the printing of the fabric C by the printing mechanism 13. In fig. 1, only the printing mechanism 13 above the support plate 14A is shown.

The driving source for driving the driving

rollers

12a and 12a, the printing mechanism 13, and the air supply mechanism 23 are connected to a control device (not shown), and the operations thereof are controlled by the control device.

The printing operation of the printing apparatus 10 according to the first embodiment is as follows. First, the cloth C is conveyed to a position below the printing mechanism 13 by the intermittent feeding operation of the conveyor belt 11 and is stopped. Then, the printing plate 13a of the printing mechanism 13 presses the fabric C from above, and the ink is transferred from the fine holes provided in the printing plate 13a to the fabric C by the movement of the squeegee, thereby printing the fabric C. At this time, the surface of the support plate 14A of the support table 14 contacts the lower surface of the conveyor belt 11 to support the cloth C. Next, the intermittent feeding operation of the conveyor belt 11 causes the fabric C to be conveyed and then stopped so that the area of the fabric C to be printed next is located below the printing mechanism 13. Then, printing is performed on the area fed below the printing mechanism 13. These operations are repeated to print the fabric C.

In the printing operation described above, the air supply mechanism 23 supplies air to the air holes 21 of the support table 14 each time the intermittent feeding operation of the transport belt 11 is performed by the belt drive mechanism 12. That is, in the stopping operation immediately before the conveying operation of the conveyor belt 11, air is supplied to the duct 22 through the air pipe 24 by the air supply mechanism 23 as shown by an arrow A1 in fig. 4, and is supplied to the air holes 21 of the support table 14 (the support plate 14E in the example shown in the figure) as shown by an arrow A2. As a result, air is fed from the air holes 21 toward the lower surface of the conveyor belt 11 as indicated by arrow A3, and the conveyor belt 11 is lifted from the support base 14, so that a gap is formed between the conveyor belt 11 and the support base 14 and is not in contact with the support base 14. In this state, the conveyor belt 11 is moved by a predetermined distance by the belt driving mechanism 12 to perform a conveying operation, and after the operation is stopped, the supply of air by the air supply mechanism 23 is stopped. Thereby, the conveyor belt 11 is lowered to the support base 14, and comes into contact with the support base 14. Thereafter, the printing mechanism 13 prints the fabric C. In this way, during the conveying operation of the conveyor belt 11, air is fed from the air holes 21 toward the lower surface of the conveyor belt 11, and the conveyor belt 11 is lifted from the support base 14, so that a gap is formed between the conveyor belt 11 and the support base 14, and is in a state of not contacting the support base 14.

According to the above configuration, since the air supply mechanism 23 supplies air to the air holes 21 of the support base 14, the conveyor belt 11 floats from the support base 14 and is supported from below by the air, and the frictional force generated between the lower surface of the conveyor belt 11 and the upper surface of the support base 14 when the conveyor belt 11 moves is reduced, the central portion of the conveyor belt 11 can be prevented from being stretched, and the conveying error can be reduced. As described above, according to the printing apparatus 10 of the present embodiment, the intermittent feeding operation of the conveyor belt 11 can be assisted.

Further, the intermittent feeding operation of the conveyor belt 11 by the belt driving mechanism 12 may be performed in a state where the conveyor belt 11 is kept in contact with the support table 14 without forming a gap between the conveyor belt 11 and the support table 14. Even in this case, since the conveyor belt 11 is supported from below by air, the frictional force generated between the lower surface of the conveyor belt 11 and the upper surface of the support table 14 when the conveyor belt 11 moves is reduced, and therefore, the central portion of the conveyor belt 11 can be prevented from being stretched, and the conveying error can be reduced.

In the present embodiment, the air supply mechanism 23 operates in synchronization with the intermittent feeding operation of the conveyor belt 11, supplies air to the lower surface of the conveyor belt 11 by the belt feeding assist mechanism 20 during the conveying operation of the conveyor belt 11, and does not supply air during the stop operation of the conveyor belt 11 and the printing operation by the printing mechanism 13. However, in the case where the supplied air does not affect the printing of the fabric C by the printing mechanism 13, the air may be continuously supplied toward the lower surface of the transport belt 11 by the belt feeding assisting mechanism 20 even during the printing operation of the printing apparatus 10. That is, the fabric C may be conveyed by the intermittent feeding operation of the conveyor belt 11, and the air may be continuously supplied toward the lower surface of the conveyor belt 11 by the belt feeding assisting mechanism 20 during the printing operation from the start to the end of the printing of the web-shaped fabric C by the fabric printing apparatus 10. In this case, it is not necessary to control the air supply mechanism 23 during the operation of the printing apparatus 10.

The belt feeding support mechanism 20 is not limited to the above-described configuration, and may be in any form as long as it can support the load of the conveyor belt 11 and reduce the frictional force between the lower surface of the conveyor belt 11 and the support base 14. For example, the gap forming mechanism may be configured such that air injection devices are disposed at both sides of the support base 14 in the width direction and at a height position aligned with the upper surface of the support base 14, and air is injected by the air injection devices to lift the conveyor belt 11 when the conveyor belt performs a conveying operation, thereby forming a gap.

Fig. 5 to 7 show a printing apparatus 10 according to a second embodiment of the present invention. In the printing apparatus 10 of the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the present embodiment, the support table 14 is provided with a group 14A of support plates 14A to 14C and a group 14b of support plates 14D to 14F at intervals in the conveying direction. Each of the

groups

14A and 14b is formed by arranging three support plates 14A to 14F, which are the same as those of the first embodiment, in series in the conveying direction. However, the configuration is not limited to this, and the support plates 14A to 14F of each group may be formed of one flat plate, or may be formed of an arbitrary number of flat plates, and the size of the support plates 14A to 14F may be arbitrary.

Between the

sets

14a, 14b of the support plates, a push-up mechanism 30 constituting a belt feed assist mechanism is disposed. The push-up mechanism 30 pushes up the conveyor belt 11 so that the conveyor belt 11 is separated from the support base 14, and as shown in fig. 7, the push-up mechanism 30 includes: a push-up member 31 that pushes up the conveyor belt 11 while abutting against the lower surface of the conveyor belt 11; and an elevating mechanism 32 that elevates the push-up member 31 so that the upper end of the push-up member 31 is exposed to and exposed from the upper surface of the support base 14.

The push-up member 31 includes two push-up

rollers

31A and 31A having a length substantially equal to the length of the support table 14 in the width direction. The push-up

rollers

31A and 31A are arranged at intervals in the conveying direction along a direction perpendicular to the conveying direction, that is, a width direction of the fabric C. Each of the push-up

rollers

31A, 31A includes a bearing or the like therein, is rotatably supported by the rotating shaft 31A, and is in contact with the lower surface of the conveyor belt 11 to rotate by the movement of the conveyor belt 11. The number of the push-up

rollers

31A and 31A may be one or three or more, but is preferably small from the viewpoint of reducing the frictional force between the conveyor belt 11 and the push-up

rollers

31A and 31A when the conveyor belt 11 moves, and is preferably large from the viewpoint of stably lifting up the conveyor belt 11, and is two in the present embodiment.

The lifting mechanism 32 is provided on both ends of the push-up

rollers

31A and 31A in the longitudinal direction (the width direction of the fabric), and includes, as shown in fig. 7: a movable plate 33; a pair of

guide brackets

34, 34 fixed to the bracket 16, a base (not shown) of the printing apparatus 10, and the like; and an actuator constituted by, for example, a hydraulic cylinder 35. The movable plate 33 has shaft support grooves 33a formed in the inner surface thereof, and both ends of the rotating shaft 31A of each of the push-up

rollers

31A, 31A are supported by the shaft support grooves 33a. The end of the movable plate 33 in the longitudinal direction (conveying direction) is slidably supported by a guide groove 34a provided in the

guide brackets

34, 34. The hydraulic cylinder 35 includes a cylinder body 35a and a rod 35b that moves in and out of the cylinder body 35a, and the tip of the rod 35b is connected to the lower surface of the movable plate 33. The push-up

rollers

31A, 31A attached to the movable plate 33 are raised and lowered along the

guide brackets

34, 34 by the operation of raising and lowering the rod 35 b. The upper ends of the push-up

rollers

31A, 31A are located below the upper surface of the support base 14 in a state where the rod 35b is pulled into the cylinder body 35a, and the upper ends of the push-up

rollers

31A, 31A are located above the upper surface of the support base 14 in a state where the rod 35b is extended from the cylinder body 35 a. The height from the upper surface of the support base 14 to the upper ends of the push-up

rollers

31A, 31A is set to about 5 to 10mm in a state where the push-up

rollers

31A, 31A abut on the lower surface of the conveyor belt 11 and push up the conveyor belt 11, but is not limited thereto.

The drive source for driving the drive rollers 12a, the printing mechanism 13, and the actuator (hydraulic cylinder 35) of the elevating mechanism 32 are connected to a control device (not shown), and the operation thereof is controlled by the control device.

The printing operation of the printing apparatus 10 according to the second embodiment is different from that of the printing apparatus 10 according to the first embodiment.

In the printing operation, during a stop operation immediately before the conveyance operation of the conveyor belt 11, the rod 35b of the hydraulic cylinder 35 of the lifting mechanism 32 is extended, the movable plate 33 is raised, the upper ends of the push-up

rollers

31A and 31A are lifted above the upper surface of the support base 14, and the conveyor belt 11 is separated from the support base 14. The conveyor belt 11 is lifted from the support base 14 by the lifting of the push-up

rollers

31A and 31A, and is in a state of not contacting the support base 14. In this state, the conveyor belt 11 is moved by a predetermined distance by the conveying operation of the belt drive mechanism 12, and at this time, the push-up

rollers

31A and 31A rotate in accordance with the movement of the conveyor belt 11. By this rotation, the frictional force between the push-up

rollers

31A, 31A and the conveyor belt 11 is reduced, thereby preventing the conveyor belt 11 from being expanded and contracted by the influence of the push-up

rollers

31A, 31A. When the conveyor belt 11 moves a predetermined distance and stops, the rod 35b of the hydraulic cylinder 35 is pulled into the cylinder main body 35a, the movable plate 33 descends, and the push-up

rollers

31A and 31A are positioned below the upper surface of the support base 14. Thereby, the conveyor belt 11 is lowered to the support table 14, and comes into contact with the support table 14. Thereafter, the printing mechanism 13 prints the fabric C. In this way, during the conveying operation of the conveyor belt 11, the conveyor belt 11 is lifted from the support base 14 by the elevating mechanism 32, and the conveyor belt 11 is in a state of not contacting the support base 14.

According to the above configuration, since the push-up

rollers

31A and 31A lift the conveyor belt 11 away from the support table 14 every time the conveyor belt 11 performs the intermittent feeding operation, no friction is generated between the lower surface of the conveyor belt 11 and the upper surface of the support table 14 when the conveyor belt 11 moves, the central portion of the conveyor belt 11 can be prevented from being stretched, and the conveying error can be reduced. As described above, according to the printing apparatus 10 of the present embodiment, the intermittent feeding operation of the conveyor belt 11 can be assisted.

The push-up

rollers

31A and 31A may be rod-shaped members that do not rotate with the movement of the conveyor belt 11. In this case, when the conveyor belt 11 is moved by a predetermined distance by the conveying operation of the belt drive mechanism 12, the push-up

rollers

31A and 31A are in contact with the lower surface of the conveyor belt 11 but do not rotate. Even in this case, the frictional force between the push-up

rollers

31A, 31A and the conveyor belt 11 is reduced as compared with the related art.

The structure of the lifting mechanism 32 is not limited to the present embodiment, and any structure may be used as long as the push-up

rollers

31A and 31A can be lifted. For example, as shown in fig. 8, the lift mechanism 32 may also be a rodless cylinder 40. The rodless cylinder 40 has a cylinder tube 40b disposed between

base portions

40a and 40a fixed to, for example, the bracket 16 and a base (not shown) of the printing apparatus 10 at upper and lower positions, a piston (not shown) is accommodated in the cylinder tube 40b, and a slider 40c is provided on an outer peripheral surface of the cylinder tube 40b, and the slider 40c is slidable along the cylinder tube 40 b. The piston moves integrally with the slider 40c by a magnetic coupling force, and the slider 40c moves following the movement of the piston by moving the piston by air, for example.

The pair of rodless cylinders 40 are provided for each of the push-up rollers 31A, the pair of rodless cylinders 40 are disposed on both end sides (in the width direction of the fabric C) of each of the push-up rollers 31A, and the tip portions of both ends of the rotating shaft 31A of the push-up

rollers

31A, 31A are fixed to the slider 40C, respectively. The slide body 40c moves up and down, and the push-up

rollers

31A and 31A move up and down so that the upper ends thereof are located between an upper position and a lower position with respect to the upper surface of the support table 14. Further, movable plates may be attached to the sliding bodies 40c of the pair of rodless cylinders 40, respectively, and distal end portions of both ends of the rotating shaft 31A of the two push-up

rollers

31A, 31A may be fixed to the respective movable plates, so that the two push-up

rollers

31A, 31A may be moved simultaneously by the pair of rodless cylinders 40.

The elevator mechanism 32 may also be a cam mechanism 50 as shown in fig. 9. The cam mechanism 50 includes: a rotary body 51 as a driving cam rotated by rotation of a motor (not shown); and a rod-shaped member 52 as an idler cam disposed above the rotating body 51. The rotor 51 has: a circular disk part 51a having a central part attached to an output shaft 51c of the motor; and a protruding portion 51b protruding outward from the disk portion 51 a. In order to reduce the frictional force between the rod 52 and the rotating body 51, a roller 52a that is rotatable by the rotation of the rotating body 51 is provided at the lower end of the rod 52, and the tip of the rotating shaft 31A of the push-up

rollers

31A, 31A is fixed to the upper end of the rod 52. When the protruding portion 51b is directed upward by the rotation of the output shaft 51c of the motor, the rod member 52 is lifted up, and the push-up

rollers

31A and 31A fixed to the rod member 52 are lifted up. When the protrusion 51b is directed in a direction other than the upward direction, for example, in the lateral direction or the downward direction, the rod 52 and the push-up

rollers

31A and 31A fixed to the rod 52 are lowered.

The push-up member 31 is not limited to the push-up

rollers

31A and 31A, and may be in any form as long as it can push up the conveyor belt 11 while contacting the lower surface of the conveyor belt 11 so that the conveyor belt 11 does not contact the upper surface of the support base 14. For example, the push-up member 31 may be a spherical body rotatably supported by the base, or may include a plurality of spherical bodies.

Further, in the embodiment shown in fig. 5, the push-up mechanism 30 is arranged between the two

support plate groups

14a, 14b, but the arrangement position of the push-up mechanism 30 is not limited to this, and for example, as shown in fig. 10, the support table 14 may include three support plate groups 14a to 14c, and the push-up mechanism 30 may be arranged between the support plate groups 14a to 14 c. In fig. 10, push-up mechanisms 30 are disposed between the group 14A of the

support plates

14A, 14B and the group 14B of the

support plates

14C, 14D, 14E, and between the group 14B of the

support plates

14C, 14D, 14E and the group 14C of the

support plates

14F, 14G, respectively. The push-up mechanisms 30 may be disposed on both ends of the support table 14 in the conveying direction.

While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

Description of reference numerals:

10: printing device

11: conveying belt

12: belt drive mechanism

13: printing mechanism

14: supporting table

20: auxiliary mechanism is fed in area

21: air hole

22: pipeline

23: air supply mechanism

30: push-up mechanism

31: push-up component

31A, 31A: push-up roller

32: lifting mechanism

33: movable plate

35: hydraulic cylinder

C: cloth (printing object)

Claims

1. A printing apparatus, comprising:

a conveyor belt that supports the printing object from below and conveys the printing object in a horizontal direction;

a belt driving mechanism for intermittently feeding the conveyor belt;

a printing mechanism which is disposed on a traveling path of the conveyor belt and prints on an object to be printed;

a support table that supports the conveyor belt from below when printing is performed by the printing mechanism; and

a belt feeding assist mechanism that assists the intermittent feeding operation of the conveyor belt by the belt drive mechanism,

the belt feeding assist mechanism has: an air hole formed in the support table; and an air supply mechanism that supplies air fed from the air holes toward the lower surface of the conveyor belt.

2. Printing device according to claim 1,

the belt feeding assist mechanism assists the intermittent feeding operation each time the belt drive mechanism performs the intermittent feeding operation of the conveyor belt.

3. Printing device according to claim 1 or 2,

the belt feeding auxiliary mechanism is a gap forming mechanism that forms a gap between the lower surface of the conveyor belt and the support table.