Conveying device

Abstract

To provide a carrying device capable of detecting a change in a surface state of a roller used for carrying a carrying object, even when the carrying object is long.SOLUTION: The platen roller 15 conveys the stencil sheet M while sandwiching the stencil sheet M between the platen roller 15 and the thermal head 13. The platen roller 15 can be brought into contact with and separated from the thermal head 13. The driven roller 17 is driven to rotate by the platen roller 15. The torque limiter 21 applies a predetermined load to the driven roller 17. The encoder 22 detects the rotation speed of the driven roller 17. The control unit drives the platen roller 15 in a state in which the platen roller 15 is separated from the thermal head 13, detects the friction coefficient of the platen roller 15 based on the rotation speed of the driven roller 17, to which the predetermined load is applied by the torque limiter 21, detected by the encoder 22, and determines the change in the state of the surface of the platen roller 15 based on the detected friction coefficient.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a conveying device. [Background technology]

[0002] A technology for detecting changes in the surface condition of rollers used to transport paper or other transported objects is disclosed in Patent Document 1. In this technology, deterioration in the surface roughness of the first and second rollers is determined based on the rotation speed of the second roller when a braking force is applied to the first roller while the first roller is driven with the first and second rollers in pressure contact with each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-3105 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology in Patent Document 1 can only determine deterioration in surface roughness for a pair of rollers that are in constant contact with each other and that convey the conveyed object while sandwiching it, so it is not suitable for conveying devices that convey long objects. For this reason, there has been a demand for technology that can detect changes in the surface condition of rollers used to convey a conveyed object, even when the conveyed object is long.

[0005] The present invention has been made in consideration of the above, and aims to provide a conveying device that can detect changes in the surface condition of rollers used to convey an object, even if the object is long. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the conveying device of the present invention conveys an object to be conveyed while sandwiching it between a contact member, and is characterized by comprising a conveying roller that can be brought into contact with and separated from the contact member, a driven roller that rotates in response to the conveying roller, a load application unit that applies a predetermined load to the driven roller, a rotational speed detection unit that detects the rotational speed of the driven roller, and a control unit that drives the conveying roller when the conveying roller is separated from the contact member, detects the friction coefficient of the conveying roller based on the rotational speed detected by the rotational speed detection unit of the driven roller to which a predetermined load has been applied by the load application unit, and determines a change in the condition of the surface of the conveying roller based on the detected friction coefficient. [Effects of the Invention]

[0007] According to the conveying device of the present invention, even if the conveyed object is long, it is possible to detect a change in the condition of the surface of the rollers used to convey the conveyed object. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing the configuration of a plate making apparatus according to an embodiment; [Figure 2] 2 is a diagram showing a schematic configuration of a plate making section of the plate making apparatus shown in FIG. 1, in which a thermal head is holding a stencil sheet between itself and a platen roller. FIG. [Figure 3] 2 is a diagram showing a schematic configuration of a plate making section of the plate making apparatus shown in FIG. 1, in which a thermal head is separated from a platen roller. FIG. [Figure 4] FIG. 2 is a view showing the vicinity of a platen roller and a driven roller of the plate making unit. [Figure 5] 6 is a flowchart illustrating an operation of detecting a change in the surface condition of a platen roller in a plate making device. [Figure 6] FIG. 10 is a graph showing the relationship between the plate making count and the friction coefficient of the platen roller. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are designated by the same or equivalent reference numerals throughout the drawings.

[0010] The following embodiments are examples of devices that embody the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not limit the materials, shapes, structures, arrangements, etc. of each component to those described below. The technical idea of ​​the present invention can be modified in various ways within the scope of the claims.

[0011] FIG. 1 is a block diagram showing the configuration of a platemaking apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the schematic configuration of the platemaking unit of the platemaking apparatus shown in FIG. 1, in a state in which a thermal head holds a stencil sheet between itself and a platen roller. FIG. 3 is a diagram showing the schematic configuration of the platemaking unit in a state in which the thermal head is separated from the platen roller. FIG. 4 is a diagram showing the vicinity of the platen roller and driven roller of the platemaking unit. In the following description, the direction perpendicular to the plane of FIG. 2 is defined as the front-rear direction, and the front direction of the plane of the plane is defined as the front. Furthermore, as shown in FIG. 2, the up, down, left, and right directions when viewed from the front are defined as the up, down, left, and right directions.

[0012] As shown in FIG. 1, a plate making apparatus (corresponding to a conveying apparatus) 1 according to this embodiment includes a plate making section 2, an operation panel section 3, and a control section 4.

[0013] 1 to 4, the platemaking section 2 makes a plate by perforating a stencil sheet. As shown in Fig. 1 to Fig. 4, the platemaking section 2 includes guide rollers 11 and 12, a thermal head (corresponding to a contact member) 13, a platemaking pressure motor 14, a platen roller (corresponding to a conveying roller) 15, a light pulse motor 16, a driven roller 17, a pressure spring 18, a pressure arm 19, an adjustment motor 20, a torque limiter (corresponding to a load applying section) 21, an encoder (corresponding to a rotational speed detecting section) 22, a cutter 23, a cutter motor 24, and a nip roller pair 25.

[0014] The guide rollers 11 and 12 guide the stencil paper (corresponding to the transported object) M between the stencil paper roll 26 accommodated in a stencil paper accommodation section (not shown) and the platen roller 15. The stencil paper roll 26 is a roll of a long stencil paper M.

[0015] The thermal head 13 writes (perforates) on the stencil paper M based on image data. The thermal head 13 is configured to be movable between a contact position shown in Fig. 2 and a non-contact position shown in Fig. 3. The contact position of the thermal head 13 is a position where it contacts the platen roller 15 from above, and the non-contact position is a position where it is spaced apart from the platen roller 15. When writing, the thermal head 13 is placed at the contact position, and writes on the stencil paper M that is transported by the rotation of the platen roller 15 while pressing the platen roller 15 through the stencil paper M.

[0016] The plate-making pressure motor 14 moves the thermal head 13 between a contact position and a non-contact position.

[0017] The platen roller 15 conveys the stencil paper M by rotating while sandwiching the stencil paper M between itself and the thermal head 13. The thermal head 13 is movable between a contact position and a non-contact position, so that the platen roller 15 can come into contact with and separate from the thermal head 13.

[0018] The light pulse motor 16 drives the platen roller 15 and the nip roller pair 25 .

[0019] The driven roller 17 is always in contact with the platen roller 15 and rotates following the rotation of the platen roller 15. The driven roller 17 is disposed below the platen roller 15. In other words, the driven roller 17 is disposed on the opposite side of the platen roller 15 from the thermal head 13, which is in contact with the platen roller 15.

[0020] The pressure spring 18 pulls one end of the pressure arm 19, thereby pressing the driven roller 17 against the platen roller 15. One end of the pressure spring 18 is connected to one end of the pressure arm 19, and the other end is connected to one end of an adjustment arm (not shown).

[0021] The pressure arm 19 presses the driven roller 17 toward the platen roller 15 by the spring force of the pressure spring 18. The pressure arm 19 has one end connected to the pressure spring 18 and the other end connected to the driven roller 17. The pressure arm 19 is rotatably supported by a rotary shaft 19a, and when one end is pulled by the pressure spring 18, the other end presses the driven roller 17 toward the platen roller 15.

[0022] The adjustment motor 20 rotates the above-mentioned adjustment arm to expand and contract the pressure spring 18, thereby changing the spring force of the pressure spring 18.

[0023] The torque limiter 21 applies a predetermined load to the driven roller 17 .

[0024] The encoder 22 outputs a pulse signal corresponding to the rotation angle of the driven roller 17. The encoder 22 is for detecting the rotation speed of the driven roller 17. The encoder 22 includes a rotary slit plate 31 and a sensor unit 32.

[0025] The rotary slit plate 31 is a circular plate with many slits. The many slits are formed at a predetermined pitch around the entire circumference of the rotary slit plate 31. The rotary slit plate 31 is attached to the driven roller 17 and rotates together with the driven roller 17.

[0026] The sensor unit 32 includes a light-emitting element and a light-receiving element (neither of which is shown) that are arranged opposite each other with the rotary slit plate 31 in between. The light-emitting element emits light toward the light-receiving element. When the rotary slit plate 31 rotates, the light from the light-emitting element passes through the slits of the rotary slit plate 31 or is blocked by the rotary slit plate 31. The light-receiving element receives the light from the light-emitting element that has passed through each slit of the rotary slit plate 31 and outputs a pulse signal.

[0027] The cutter 23 cuts the stencil paper M perforated by the thermal head 13 .

[0028] The cutter motor 24 drives the cutter 23 .

[0029] The nip roller pair 25 nips the stencil sheet M conveyed by the thermal head 13 and the platen roller 15, and conveys it, for example, toward a printing section of a stencil printing machine in which the stencil making device 1 is provided.

[0030] The operation panel unit 3 displays various input screens and accepts user input operations. The operation panel unit 3 includes a display unit such as a liquid crystal display panel, and an input unit such as operation buttons and a touch panel (neither of which are shown).

[0031] The control unit 4 controls the overall operation of the plate making apparatus 1. The control unit 4 is configured with a CPU, RAM, ROM, a hard disk, and the like.

[0032] When the plate making device 1 is powered on, the control unit 4 performs a friction detection operation to detect changes in the surface condition of the platen roller 15. Specifically, the control unit 4 drives the platen roller 15 while the platen roller 15 is separated from the thermal head 13, detects the coefficient of friction (dynamic coefficient of friction) μ of the platen roller 15 based on the rotation speed detected by the encoder 22 of the driven roller 17 to which a predetermined load is applied by the torque limiter 21, and determines changes in the surface condition of the platen roller 15 based on the detected coefficient of friction μ.

[0033] Next, the operation of detecting changes in the surface condition of the plate roller 15 in the plate making apparatus 1 will be described with reference to the flowchart of FIG.

[0034] In step S1 of FIG. 5, the control unit 4 detects that the plate making device 1 has been powered on.

[0035] Next, in step S2, the control unit 4 controls the plate-making pressure motor 14 to place the thermal head 13 in the non-contact position.

[0036] Next, in step S3, the control unit 4 executes a friction detection operation. Specifically, first, the control unit 4 controls the light pulse motor 16 to start driving the platen roller 15 and rotate it at a predetermined rotation speed. As the platen roller 15 rotates, the driven roller 17, to which a predetermined load is applied by the torque limiter 21, rotates in conjunction with the platen roller 15. In addition, the encoder 22 outputs a pulse signal corresponding to the rotation angle of the driven roller 17.

[0037] The control unit 4 calculates the rotation speed of the driven roller 17 based on the output pulse signal of the encoder 22. Then, the control unit 4 detects the friction coefficient μ of the platen roller 15 based on the calculated rotation speed. Here, the lower the rotation speed of the driven roller 17, the smaller the friction coefficient μ of the platen roller 15.

[0038] Next, in step S4, the control unit 4 determines whether the friction coefficient μ2 of the platen roller 15 detected in the friction detection operation is less than a predetermined threshold μ1. The threshold μ1 is a preset value of the friction coefficient μ that indicates that the surface condition of the platen roller 15 is in a state where a problem occurs in the transport of the stencil paper M.

[0039] Here, as shown in Fig. 6, the friction coefficient μ of the platen roller 15 changes so as to decrease as the platemaking count, which indicates the number of times platemaking has been performed in the platemaking device 1, increases. The change in the friction coefficient μ of the platen roller 15 indicates a change in the surface condition of the platen roller 15. The change in the surface condition of the platen roller 15 affects the transport of the stencil paper M. In the example of Fig. 5, the friction coefficient μ2 detected in the friction detection operation is larger than the threshold value μ1, and is a value at which it is assumed that no problems will occur in the transport of the stencil paper M.

[0040] Returning to FIG. 5, if it is determined that the friction coefficient μ2 is less than the threshold μ1 (step S4: YES), in step S5, the control unit 4 causes the display unit of the operation panel unit 3 to display a message urging cleaning of the platen roller 15.

[0041] Here, if the friction coefficient μ2 is less than the threshold μ1, the control unit 4 determines that the surface condition of the platen roller 15 is in a state requiring cleaning, and displays the message as described above. If the user who has confirmed the message cleans the platen roller 15, problems in the transport of the stencil sheet M can be prevented in advance.

[0042] If it is determined that the friction coefficient μ2 is equal to or greater than the threshold value μ1 (step S4: NO), the control unit 4 switches the plate making device 1 to the normal mode in step S6.

[0043] In the plate making device 1, the control unit 4 controls the adjustment motor 20 to change the spring force of the pressure spring 18 in accordance with the plate making count, thereby changing the pressure of the driven roller 17 against the platen roller 15. Specifically, the control unit 4 controls the pressure spring 18 so that the spring force of the pressure spring 18 increases as the plate making count increases.

[0044] As described above, in the plate making device 1, the control unit 4 drives the platen roller 15 while the platen roller 15 is separated from the thermal head 13, detects the friction coefficient μ of the platen roller 15 based on the rotation speed detected by the encoder 22 of the driven roller 17 to which a predetermined load is applied by the torque limiter 21, and determines changes in the surface condition of the platen roller 15 based on the detected friction coefficient μ. In this way, changes in the surface condition of the platen roller 15 used to transport the long stencil sheet M can be detected.

[0045] In the above-described embodiment, the plate making device 1 is described in which the platen roller 15, which is capable of coming into contact with and separating from the thermal head 13, conveys the stencil sheet M while sandwiching it between the thermal head 13. However, the present invention is not limited to this, and can be applied to a conveying device that includes a conveying roller, which is capable of coming into contact with and separating from a contact member, and conveys an object to be conveyed while sandwiching it between the contact member and the conveying roller.

[0046] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be created by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments.

[0047] [Note] The present application discloses the following inventions.

[0048] (Appendix 1) a conveying roller that conveys an object while sandwiching it between itself and a contact member, the conveying roller being capable of coming into contact with and separating from the contact member; a driven roller that rotates following the conveying roller; a load applying unit that applies a predetermined load to the driven roller; a rotation speed detection unit that detects the rotation speed of the driven roller; a control unit that drives the conveying roller in a state where the conveying roller is separated from the contact member, detects a friction coefficient of the conveying roller based on the rotation speed of the driven roller to which a predetermined load is applied by the load application unit, detected by the rotation speed detection unit, and determines a change in the surface condition of the conveying roller based on the detected friction coefficient; A conveying device comprising: [Explanation of symbols]

[0049] 1 Plate making equipment 2 Plate making department 3 Operation panel 4. Control section 11,12 Guide roller 13 Thermal head 14 Plate making pressure motor 15 Platen roller 16 Light Pulse Motor 17 Driven roller 18 Pressure spring 19 Pressure arm 20 Adjustment motor 21 Torque limiter 22 Encoder 23 cutter 24 cutter motor 25 Nip roller pair 31 Rotating slit plate 32 Sensor section

Claims

[Claim 1] a conveying roller that conveys an object while sandwiching it between itself and a contact member, the conveying roller being capable of coming into contact with and separating from the contact member; a driven roller that rotates following the conveying roller; a load applying unit that applies a predetermined load to the driven roller; a rotation speed detection unit that detects the rotation speed of the driven roller; a control unit that drives the conveying roller in a state where the conveying roller is separated from the contact member, detects a friction coefficient of the conveying roller based on the rotation speed of the driven roller to which a predetermined load is applied by the load application unit, detected by the rotation speed detection unit, and determines a change in the surface condition of the conveying roller based on the detected friction coefficient; A conveying device comprising:

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