Printing device for electric wires

Abstract

An electric wire printing device 10 according to the present invention comprises: an inkjet head 30 that performs printing onto an electric wire 5 by discharging ink; a conveyance device 20 that conveys the electric wire 5; and a drying device 40 that is provided downstream of the inkjet head 30 in the conveyance direction of the electric wire 5 and that blows air onto the printed portion of the electric wire 5.

Description

[Technical field]

[0001] The present invention relates to a printing device for electric wires. [Background technology]

[0002] Printing on electric wires has been practiced for some time. For example, Patent Document 1 discloses a method for manufacturing a wire harness, which includes printing, on electric wires, circuit information indicating connection destinations of the electric wires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-181396 A Summary of the Invention [Problem to be solved by the invention]

[0004] Printing on the electric wire as described above can be performed using an inkjet head that ejects ink toward the print substrate. However, it takes time for the ink that has landed on the electric wire to dry. In addition, if the next process is performed before the ink dries, problems such as bleeding of the print tend to occur. For this reason, it has been time-consuming to manufacture electric wires using inkjet printing.

[0005] The present invention has been made in consideration of the above points, and its object is to provide an electric wire printing device that prints on electric wires using an inkjet method and that can dry ink in a short period of time. [Means for solving the problem]

[0006] The printing device for an electric wire according to the present invention includes an inkjet head that prints on an electric wire by ejecting ink, a transport device that transports the electric wire, and a drying device that is disposed downstream of the inkjet head in the transport direction of the electric wire and blows air onto the printed portion of the electric wire.

[0007] According to the above-mentioned electric wire printing device, the drying of the ink on the printed portion of the electric wire is accelerated by the air blown by the drying device onto the printed portion of the electric wire, so that the ink can be dried in a short time.

[0008] According to a preferred embodiment of the present invention, the conveying device is configured to convey the electric wire while the drying device is blowing air onto the printed portion of the electric wire. The drying device blows air upstream in the conveying direction of the electric wire.

[0009] According to this aspect, the direction in which the electric wire is conveyed by the conveying device is opposite to the direction in which the air flows, so that the relative speed of the air flow with respect to the electric wire is the sum of the conveying speed of the electric wire and the speed of the air, which further accelerates the drying of the ink.

[0010] According to a preferred aspect of the present invention, the conveying device conveys the electric wire in a longitudinal direction of the electric wire. The drying device includes a cylindrical member provided so as to surround a periphery of a conveying path of the electric wire. An internal space through which the electric wire passes is defined inside the cylindrical member. The cylindrical member includes a supply port that opens into the internal space and through which compressed air is supplied, and an opening that communicates the internal space with the outside of the cylindrical member so that the compressed air can be discharged from the internal space.

[0011] According to this aspect, the printed portion of the electric wire is surrounded by the cylindrical member, so that the compressed air supplied to the inside of the cylindrical member is less likely to diffuse to the surroundings, improving the efficiency of drying the ink. As a result, the ink can be dried in a shorter time.

[0012] According to a preferred aspect of the above aspects, the conveying device is configured to convey the electric wire when compressed air is supplied from the supply port, and the opening is provided upstream of the supply port in a conveying direction of the electric wire.

[0013] According to this aspect, the direction in which the electric wire is conveyed by the conveying device is opposite to the direction in which the compressed air flows, which further promotes drying of the ink for the reasons described above.

[0014] According to a preferred embodiment of the above aspects, the opening is provided at an end of the tubular member on an upstream side in a conveying direction of the electric wire. The conveying device inserts the electric wire from the opening into the internal space of the tubular member.

[0015] According to this aspect, the inlet for the electric wires into the cylindrical member and the outlet for the compressed air from the cylindrical member are shared, which allows the structure of the cylindrical member to be simplified.

[0016] According to a preferred embodiment of the present invention, the cylindrical member has an electric wire outlet through which the electric wire can pass and provided at an end portion downstream in a conveying direction of the electric wire, the electric wire outlet having an opening area smaller than an opening area of ​​the opening portion.

[0017] According to this aspect, since the opening area of ​​the electric wire outlet is smaller than the opening area of ​​the opening, the compressed air easily flows toward the opening.

[0018] In a preferred embodiment among the embodiments including a tubular member, the supply port penetrates the tubular member in a direction intersecting with a longitudinal direction of the electric wire.

[0019] According to this aspect, the compressed air can easily swirl around the electric wire. When the compressed air swirls around the electric wire, the ink can be dried regardless of the orientation of the printed portion. For example, even if the orientation of the printed portion is not as set due to circumferential twisting of the electric wire, the ink can be dried.

[0020] According to a preferred embodiment of the above aspects, the supply port is provided so as to be offset from a transport path of the electric wire when viewed in a penetration direction of the supply port.

[0021] According to this aspect, by offsetting the supply port from the transport path of the electric wire, the compressed air supplied from the supply port is prevented from directly hitting the printed portion, and therefore deterioration of print quality caused by directly spraying compressed air onto wet ink can be suppressed. Effect of the Invention

[0022] According to the electric wire printing device of the present invention, the ink ejected onto the electric wire can be dried in a short time. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an electric wire printing device according to an embodiment. [Diagram 2] FIG. 2 is a schematic plan view showing an example of an electric wire after printing. [Diagram 3] FIG. 4 is a partial cross-sectional view of the guide pipe as viewed from the side. [Figure 4] FIG. 4 is a vertical cross-sectional view of a guide pipe passing through an air supply port. [Diagram 5] FIG. 4 is a cross-sectional view of the guide pipe as viewed from the side, illustrating a schematic flow of compressed air. [Figure 6] FIG. 4 is a cross-sectional view of the guide pipe as viewed from the rear, illustrating a schematic flow of compressed air. [Figure 7] FIG. 13 is a schematic diagram illustrating a configuration of an electric wire printing device according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [Printing device configuration] Fig. 1 is a schematic diagram showing the configuration of an electric wire printing device 10 (hereinafter referred to as the printing device 10) according to one embodiment of the present invention. In the following description, the left side, right side, upper side, lower side, front side of the page, and rear side of the page in Fig. 1 are respectively defined as the front side, rear side, upper side, lower side, left side, and right side of the printing device 10. The symbols F, Rr, U, D, L, and R in the drawings respectively mean the front, rear, upper side, lower side, left side, and right side of the printing device 10. However, the directions in the following description are merely defined for the convenience of explanation, and do not limit the present invention in any way.

[0025] 1, a printing device 10 according to this embodiment includes a conveying device 20 that conveys an electric wire 5, an inkjet head 30 that prints on the electric wire 5, a drying device 40 that dries the ink that has landed on the electric wire 5, and a control device 70. In front of the printing device 10, a clamp 90 that holds the printed electric wire 5 and a cutting device for the electric wire 5 (not shown) are provided.

[0026] The conveying device 20 is configured to convey the electric wire 5 in the longitudinal direction of the electric wire 5. In this embodiment, the front is downstream in the conveying direction of the electric wire 5. The rear is upstream in the conveying direction of the electric wire 5. However, the conveying direction of the electric wire 5 is not limited to the front-rear direction. In the following, the upstream and downstream in the conveying direction of the electric wire 5 are simply referred to as upstream and downstream as appropriate. As shown in FIG. 1, the conveying device 20 includes a pair of conveying rollers 21 and a conveying motor 22 that rotates one of the conveying rollers 21. The pair of conveying rollers 21 face each other. The electric wire 5 is sandwiched between the pair of conveying rollers 21. In this state, the one of the conveying rollers 21 rotates, whereby the electric wire 5 is conveyed in the longitudinal direction.

[0027] The inkjet head 30 is provided downstream of the conveying device 20. The conveying device 20 conveys the electric wire 5 before printing to the inkjet head 30. The inkjet head 30 is configured to print on the electric wire 5 by ejecting ink. FIG. 2 is a schematic plan view showing an example of the electric wire 5 after printing. As shown in FIG. 2, the inkjet head 30 forms a print 7 on the outermost coating 6 of the electric wire 5 by ejecting ink. The coating 6 is an insulating coating that covers the core wire of the electric wire 5, and is made of, for example, resin. The print 7 is formed, for example, a character, a symbol, a figure, or the like that represents information such as the specification, use, orientation, and model of the electric wire 5. However, the image printed on the electric wire 5 is not limited to the above. The color of the print 7 is also not particularly limited. The color that constitutes the print 7 may be a plurality of colors.

[0028] The inkjet head 30 includes a number of nozzles 31 that eject ink downward. The nozzles 31 are provided on the lower surface of the inkjet head 30. The nozzles 31 are located above the transport path R1 of the electric wire 5 by the transport device 20. The ink ejected from the nozzles 31 of the inkjet head 30 is a solvent ink in which a dye or a pigment is dissolved in a solvent. The solvent ink solidifies when the solvent evaporates. The ink ejected from the inkjet head 30 is not particularly limited as long as it solidifies when the solvent evaporates. The ink may be, for example, a water-based ink in which the solvent is water. Since the solvent evaporates naturally, the ink can be naturally dried. However, it takes a certain amount of time for the ink to naturally dry.

[0029] The drying device 40 is provided downstream of the inkjet head 30 in the transport direction of the electric wire 5. The transport device 20 transports the electric wire 5 after printing by the inkjet head 30 from below the inkjet head 30 to the drying device 40. The drying device 40 is a device that dries the ink on the electric wire 5 by blowing air onto the printed portion of the electric wire 5. However, the drying device 40 may blow a gas other than air onto the printed portion of the electric wire 5. The drying device 40 quickly volatilizes the ink solvent, thereby solidifying the ink in a short time. As shown in FIG. 1, the drying device 40 includes a cylindrical guide pipe 50 provided so as to surround the periphery of the transport path R1 of the electric wire 5, and an air supply unit 60 that supplies compressed air to the guide pipe 50. Inside the guide pipe 50, an internal space S1 through which the electric wire 5 passes is defined. Here, the guide pipe 50 has an insertion hole 51 into which the electric wire 5 is inserted. The space radially inward of the insertion hole 51 constitutes an internal space S1. The conveying device 20 conveys the electric wire 5 so as to pass through the insertion hole 51.

[0030] Fig. 3 is a partial cross-sectional view of the guide pipe 50 as viewed from the side. Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 3. Fig. 4 shows a longitudinal cross-section of the guide pipe 50 cut along a plane extending in the left-right and up-down directions. As shown in Figs. 3 and 4, the guide pipe 50 includes an insertion hole 51 that forms an internal space S1, an air supply port 52 that opens into the internal space S1, and a joint seat surface 53 for an air joint 61 (see Fig. 1) that is connected to the air supply port 52. The air supply port 52 is a hole through which compressed air generated by an external air compressor 80 (see Fig. 1) is supplied.

[0031] The insertion hole 51 penetrates the guide pipe 50 in the front-rear direction. As shown in FIG. 3, the insertion hole 51 includes a large diameter portion 51a, a small diameter portion 51b, a tapered portion 51c, an entrance opening 51d, and an electric wire exit 51e. The large diameter portion 51a forms an upstream portion of the insertion hole 51. As shown in FIG. 4, the large diameter portion 51a has a cylindrical shape. As shown in FIG. 3, the diameter of the large diameter portion 51a is configured to be larger than the diameter of the electric wire 5 (see the transport path R1 of the electric wire 5). Here, the diameter of the large diameter portion 51a is larger than 1.5 times the diameter of the electric wire 5. When the electric wire 5 is inserted into the insertion hole 51, a cylindrical gap is formed between the inner wall of the large diameter portion 51a and the electric wire 5.

[0032] The inlet opening 51d is opened so as to communicate the internal space S1 with the outside of the guide pipe 50. Here, the inlet opening 51d is provided at the upstream end of the guide pipe 50. The inlet opening 51d is the upstream end of the large diameter portion 51a. The conveying device 20 inserts the electric wire 5 into the internal space S1 of the guide pipe 50 from the inlet opening 51d. As will be described in detail later, the inlet opening 51d also serves as an exhaust port for discharging the compressed air supplied from the air supply port 52 from the internal space S1.

[0033] The small diameter portion 51b forms a downstream portion of the insertion hole 51. As shown in FIG. 4, the small diameter portion 51b also has a cylindrical shape. When viewed in the front-rear direction, the small diameter portion 51b forms a concentric circle with the large diameter portion 51a. The diameter of the small diameter portion 51b is smaller than the diameter of the large diameter portion 51a and is approximately the same as the diameter of the electric wire 5. The diameter of the small diameter portion 51b is slightly larger than the diameter of the electric wire 5 so that the electric wire 5 can pass through. The tapered portion 51c is formed between the large diameter portion 51a and the small diameter portion 51b. The tapered portion 51c has a tapered shape in which the diameter becomes smaller toward the downstream in the transport direction of the electric wire 5.

[0034] The electric wire outlet 51e is provided at the downstream end of the guide pipe 50. The electric wire outlet 51e is an outlet for the electric wire 5 configured to allow the electric wire 5 to pass through. Here, the electric wire outlet 51e is the downstream end of the small diameter portion 51b. The opening area of ​​the electric wire outlet 51e is configured to be smaller than the opening area of ​​the inlet opening 51d.

[0035] As shown in Fig. 3, the air supply port 52 opens on a side surface of the guide pipe 50. As shown in Fig. 4, the air supply port 52 penetrates the guide pipe 50 in a direction intersecting the longitudinal direction (here, the front-rear direction) of the electric wire 5. Here, the air supply port 52 penetrates the guide pipe 50 in a diagonal left-right direction so as to be perpendicular to the front-rear direction which is the conveying direction of the electric wire 5, and reaches the inner wall of the large diameter portion 51a. Due to the arrangement of the air supply port 52, the inlet opening 51d is located upstream of the air supply port 52 in the conveying direction of the electric wire 5. Also, due to the arrangement of the air supply port 52, the electric wire outlet 51e is located downstream of the air supply port 52 in the conveying direction of the electric wire 5.

[0036] A screw 52a is formed on the inner wall of the air supply port 52. The air joint 61 has a threaded portion that meshes with the screw 52a, and is connected to the air supply port 52. A joint seat surface 53 is formed around the outer end portion of the air supply port 52 (the end portion exposed on the outer surface of the guide pipe 50) so as to be perpendicular to the axis Ax1 of the air supply port 52.

[0037] 3, the air supply port 52 (here, meaning the actual air supply port 52, i.e., the flow path inside the air fitting 61, and indicated by the symbol 52b; see also FIG. 4) is provided so as to be offset from the conveying path R1 of the electric wire 5 when viewed from the penetration direction of the air supply port 52. The axis Ax1 of the air supply port 52 is offset from the axis Ax2 of the insertion hole 51 (which is also the center line of the conveying path R1 of the electric wire 5) so as not to intersect with it.

[0038] The air supply unit 60 controls the supply of compressed air to the air supply port 52. The compressed air is generated by an external air compressor 80. However, the printing device 10 may also be equipped with a device for generating compressed air, such as an air compressor. As shown in FIG. 1, the air supply unit 60 includes an air joint 61, an air flow path 62, an opening / closing valve 63, a pressure reducing valve 64, a flow rate adjustment valve 65, and a heater 66.

[0039] The air joint 61 is engaged with the screw 52a of the air supply port 52. The air joint 61 abuts against the joint seat surface 53. The air flow path 62 connects the air compressor 80 and the air joint 61. Here, the air flow path 62 is a flexible tube. One end of the air flow path 62 is connected to the air joint 61, and the other end is connected to the air compressor 80.

[0040] The on-off valve 63, the pressure reducing valve 64, and the flow rate control valve 65 are provided in the air flow path 62. The on-off valve 63 closes or opens the air flow path 62. The on-off valve 63 is, for example, an electromagnetic valve. The on-off valve 63 is connected to and controlled by the control device 70. The on-off valve 63 opens or closes the air flow path 62 under the control of the control device 70, thereby supplying or stopping the supply of compressed air to the drying device 40. The pressure reducing valve 64 reduces the pressure of the compressed air generated by the air compressor 80 to a pressure suitable for use in the drying device 40. The flow rate control valve 65 adjusts the flow rate of the compressed air to a flow rate suitable for use in the drying device 40.

[0041] The heater 66 heats the compressed air in the air flow path 62. Here, the heater 66 is a tape-shaped heater wrapped around the air flow path 62. The heater 66 heats the air flow path 62, thereby heating the compressed air in the air flow path 62. Due to the heating by the heater 66, air warmer than the normal temperature (the air temperature around the drying device 40) is blown onto the electric wires 5 in the drying device 40. The temperature of the heater 66 may be controlled by the control device 70. Alternatively, the control device 70 may only control the activation and stopping of the heater 66, and the temperature of the heater 66 may be controlled by the heater 66.

[0042] The above-described configuration of the air supply unit 60 is a preferred example, and is not limited thereto. The air flow path 62 is not limited to a tube, and may be, for example, a non-flexible pipe. The opening and closing valve 63 is not limited to an electromagnetic valve, and may be, for example, a motor-driven valve. The heater 66 is not limited to a wrappable sheet-like heater, and may be a hot air generator that heats the air passing through. The heater 66 may heat the guide pipe 50. The drying device 40 may not include the heater 66. The drying device 40 may not necessarily include the opening and closing valve 63, the pressure reducing valve 64, or the flow rate adjusting valve 65.

[0043] The control device 70 is connected to the conveying device 20, the inkjet head 30, and the drying device 40, and controls the operations of these devices. The configuration of the control device 70 is not particularly limited. The control device 70 may include, for example, a central processing unit (CPU), a ROM in which programs executed by the CPU are stored, and a RAM. The processing unit of the control device 70 may be configured by software or by hardware. Furthermore, each processing unit may be a processor or a circuit. The control device 70 may be, for example, a programmable controller or a computer. The control device 70 may be a computer dedicated to the printing device 10, or may be a general-purpose computer such as a personal computer. The control device 70 may be a computer on the cloud.

[0044] [Printing process] An example of a process for printing on the electric wire 5 by the printing device 10 will be described below. However, the printing process described below is merely a preferred example, and the printing process on the electric wire 5 is not limited to the following. According to a preferred example of the printing process on the electric wire 5, in the first step, the electric wire 5 is conveyed below the inkjet head 30 by the conveying device 20. The inkjet head 30 is driven while the electric wire 5 passes below, and prints a predetermined print 7 on the coating 6 of the electric wire 5 being conveyed. At this point, the ink of the print 7 is not yet dry, and is in a state where it may bleed or disappear if it comes into contact with another object, for example.

[0045] In this embodiment, the air supply unit 60 starts supplying compressed air to the guide pipe 50 at the same time or almost the same time as the conveyance of the electric wire 5 starts. However, the timing at which the supply of compressed air to the guide pipe 50 starts is not particularly limited.

[0046] When the ink ejection onto the electric wire 5 is completed, the electric wire 5 is inserted into the insertion hole 51 of the guide pipe 50 by the conveying device 20. The conveying device 20 inserts the electric wire 5 into the guide pipe 50 from the entrance opening 51d. The conveying device 20 continues conveying the electric wire 5. As a result, the front end of the electric wire 5 is inserted into the small diameter portion 51b of the insertion hole 51. The electric wire 5 is not necessarily formed in a straight line, and may be slightly curved or bent. Such an electric wire 5 is also guided into the small diameter portion 51b by the tapered portion 51c. The electric wire 5 may be twisted in the circumferential direction, in which case the print 7 may not face upward.

[0047] Thereafter, the front end of the electric wire 5 exits the guide pipe 50 from the electric wire exit 51e. The part of the electric wire 5 that has exited the guide pipe 50 passes inside the claws of the clamp 90. At this time, the ink of the print 7 has completely dried and solidified, so the print 7 will not smudge or disappear even if the clamp 90 is touched. When the electric wire 5 enters a cutter (not shown) provided further downstream in the conveying direction than the clamp 90 by a predetermined length, the conveyance of the electric wire 5 is stopped. The electric wire 5 is gripped by the clamp 90 at this position and cut to a predetermined length by the cutter. After this, while the electric wire 5 is already inserted into the guide pipe 50, the printing of the print 7, drying, and cutting of the electric wire 5 are repeated in the same manner as described above.

[0048] The state inside the guide pipe 50 into which the electric wire 5 is inserted will be described below. FIG. 5 is a cross-sectional view of the guide pipe 50 seen from the side, and is a diagram that typically illustrates the flow of compressed air. FIG. 6 is a cross-sectional view of the guide pipe 50 seen from the rear, and is a diagram that typically illustrates the flow of compressed air. Arrows W in FIGS. 5 and 6 indicate the flow of compressed air. As shown in FIG. 6, the compressed air flowing from the air supply port 52 into the internal space S1 of the guide pipe 50 flows so as to swirl around the conveying path R1 of the electric wire 5 when viewed in the front-rear direction. In this embodiment, the air supply port 52 (here, the actual air supply port 52b) is provided so that its extension in the axis Ax1 direction does not intersect with the conveying path R1 of the electric wire 5. Therefore, the compressed air flowing from the air supply port 52 into the internal space S1 is likely to flow so as to swirl around the conveying path R1 of the electric wire 5. In addition, the compressed air flowing from the air supply port 52 into the internal space S1 is not blown directly onto the wires 5, particularly onto the markings 7.

[0049] As shown in FIG. 5, after the electric wire 5 is inserted into the small diameter portion 51b of the insertion hole 51, the electric wire outlet 51e is almost blocked by the electric wire 5. Therefore, the outlet of the compressed air flow W from the guide pipe 50 is almost limited to the inlet opening 51d. As a result, the compressed air flows toward the upstream side in the conveying direction of the electric wire 5. As shown in FIG. 5, the compressed air flows toward the upstream side in the conveying direction of the electric wire 5 while spirally circulating around the electric wire 5. The opening area of ​​the inlet opening 51d is at least larger than the opening area of ​​the electric wire outlet 51e, and therefore larger than the cross-sectional area of ​​the electric wire 5. Therefore, the inlet opening 51d is not blocked by the electric wire 5. As a result, a compressed air flow W toward the upstream side in the conveying direction of the electric wire 5 is generated.

[0050] The flow W of compressed air spirally circulating around the electric wire 5 and moving toward the upstream side in the conveying direction of the electric wire 5 is advantageous for drying the ink of the print 7. First, the guide pipe 50 is formed in a cylindrical shape so as to surround the conveying path R1 of the electric wire 5, so that the compressed air supplied into the guide pipe 50 is less likely to diffuse to the surroundings. Therefore, the ink can be dried in a shorter time than, for example, blowing compressed air onto the print 7 in a free space. In addition, the amount of compressed air used can be saved. Furthermore, since the guide pipe 50 is formed in a cylindrical shape, the compressed air supplied from the air supply port 52 swirls within the internal space S1 of the guide pipe 50. As a result, even if the orientation of the print 7 is not as set due to, for example, circumferential twisting of the electric wire 5, the swirled compressed air is blown onto the print 7. According to the drying device 40 of this embodiment, even if the orientation of the print 7 is not as set (or, more specifically, whatever the orientation of the print 7 is), the ink of the print 7 can be dried.

[0051] In this embodiment, the air supply port 52 penetrates the guide pipe 50 in a direction intersecting the longitudinal direction of the electric wire 5. This makes it easier for the compressed air to swirl around the electric wire 5. Furthermore, in this embodiment, the air supply port 52 (here, the actual air supply port 52b) is provided so as to be offset from the transport path R1 of the electric wire 5 when viewed in the penetrating direction of the air supply port 52. This also promotes the swirling of the compressed air around the electric wire 5. In addition, the compressed air flowing in from the air supply port 52 is prevented from directly hitting the print 7. If the compressed air is directly sprayed onto the undried ink of the print 7, the ink may be blown away or moved, thereby degrading the quality of the print 7. The drying device 40 according to this embodiment can reduce such a risk.

[0052] In this embodiment, the flow W of compressed air in the guide pipe 50 is directed toward the upstream side in the conveying direction, and this flow direction is the opposite direction to the conveying direction of the electric wire 5 by the conveying device 20. The conveying device 20 conveys the electric wire 5 downstream in a state in which compressed air is supplied from the air supply port 52 into the internal space S1. Therefore, the relative speed of the flow W of compressed air to the electric wire 5 is the sum of the conveying speed of the electric wire 5 and the speed of the compressed air. As a result, the relative speed of the flow W of compressed air to the electric wire 5 becomes faster, and the drying of the ink of the print 7 is further promoted. Such a flow of compressed air is generated by providing the inlet opening 51d upstream of the air supply port 52 in the conveying direction of the electric wire 5. Note that, in this embodiment, the inlet opening 51d is provided at the end of the upstream side of the guide pipe 50, and serves both as the inlet of the electric wire 5 into the guide pipe 50 and the outlet of the compressed air from the guide pipe 50. This simplifies the structure of the guide pipe 50.

[0053] Furthermore, in this embodiment, the opening area of ​​the electric wire outlet 51e is smaller than the opening area of ​​the inlet opening 51d. This makes it easier for the compressed air in the guide pipe 50 to flow upstream in the transport direction of the electric wire 5. In this embodiment, the opening area of ​​the electric wire outlet 51e is approximately the same as the cross-sectional area of ​​the electric wire 5, so that when the electric wire 5 passes through the electric wire outlet 51e, the electric wire outlet 51e is almost closed by the electric wire 5. This causes the compressed air in the guide pipe 50 to flow upstream in the transport direction of the electric wire 5.

[0054] The inventors of the present application have confirmed through simulation that the compressed air flows toward the upstream side in the conveying direction of the electric wire 5 while spirally circulating around the electric wire 5 (flowing as shown in Figs. 5 and 6). The inventors of the present application have also confirmed that by using the printing device 10 according to this embodiment, the ink of the print 7 can be dried in a much shorter time than natural drying. The temperature of the compressed air contributes to shortening the drying time of the print 7, but since it is difficult to maintain the temperature of the air that flows and is replaced in the air flow path 62, the compressed air may or may not be heated. According to trials by the inventors of the present application, even if the temperature of the compressed air is room temperature, the ink of the print 7 can be dried in a short time. However, for example, by using a hot air generator or the like, the temperature of the air supplied to the air supply port 52 can be stably maintained.

[0055] [Other embodiments] A preferred embodiment has been described above. However, the above embodiment is merely an example, and various other embodiments are possible. For example, in the above embodiment, the compressed air is blown onto the ink of the print 7 while the electric wire 5 is moving, but the blowing may be performed while the electric wire is stopped. In the above embodiment, the inlet opening 51d from which the compressed air exits is open toward the upstream side in the conveying direction of the electric wire 5, but it may be open toward the downstream side in the conveying direction of the electric wire or toward another direction. The opening from which the compressed air exits does not have to be the inlet opening into which the electric wire is inserted.

[0056] In the above embodiment, the guide pipe 50 has the electric wire outlet 51e, but the guide pipe 50 may not have the electric wire outlet 51e. In that case, the electric wire may be returned to the upstream side in the transport direction after the ink dries. The transport direction of the electric wire is not limited to the longitudinal direction of the electric wire. The electric wire may be moved, for example, in a parallel movement or a rotational movement in a direction intersecting the longitudinal direction.

[0057] The configuration of the cylindrical member, exemplified by the guide pipe 50, is not particularly limited. The cylindrical member is provided so as to surround the periphery of the electric wire transport path, and is not limited any further as long as it has an air supply port through which compressed air is supplied and an opening through which the compressed air is discharged. For example, the air supply port may be provided substantially parallel to the electric wire transport path. In addition, the cylindrical member may be cylindrical when drying the printing ink, and may have other shapes when the ink is not dried. For example, the cylindrical member may have a movable part and be configured to change shape.

[0058] Furthermore, the wire printer may not include a cylindrical member such as the guide pipe 50. FIG. 7 is a schematic diagram showing the configuration of a wire printer 10 according to another embodiment. In the following description of the embodiment, the same reference numerals are used for members having the same functions as those in the above embodiment. As shown in FIG. 7, the wire printer 10 according to this embodiment includes an inkjet head 30 that prints on the wire 5 by ejecting ink, a conveying device 20 that conveys the wire 5 after printing by at least the inkjet head 30, and a drying device 40 that does not include a cylindrical member. As in the first embodiment, the drying device 40 is provided downstream of the inkjet head 30 in the conveying direction of the wire 5. The drying device 40 according to this embodiment includes an air nozzle 41 that blows air onto the printed portion of the wire 5. The air nozzle 41 is connected to an external air compressor 80 via an air flow path 62. The air flow path 62 is provided with an opening / closing valve 63, a pressure reducing valve 64, a flow rate control valve 65, and a heater 66. In this embodiment, air is blown from an air nozzle 41 directly onto the markings 7 on the electric wire 5 .

[0059] As shown in FIG. 7, in this embodiment, the drying device 40 is configured to blow air toward the upstream in the transport direction of the electric wire 5. As in the first embodiment, the transport device 20 is configured to transport the electric wire 5 while the drying device 40 is blowing air to the printed portion of the electric wire 5. This increases the relative speed between the air flow W and the electric wire 5. However, the drying device 40 does not have to be configured to blow air toward the upstream in the transport direction of the electric wire 5. For example, the drying device 40 may be configured to blow air in a direction perpendicular to the transport direction of the electric wire 5. In this specification, "blow air toward a certain direction" generally includes the creation of an air flow toward a predetermined direction by the configuration of the flow path, for example, as in the first embodiment.

[0060] 7, the ink of the print 7 can be dried in a shorter time than natural drying. The number of air nozzles 41 is not particularly limited, and a plurality of air nozzles may be provided. The air blown onto the print 7 on the electric wire 5 does not have to be compressed air generated by an air compressor or the like. The drying device 40 may include, for example, a blower fan that blows air onto the print 7 on the electric wire 5.

[0061] Unless otherwise specified, the embodiments do not limit the present invention. [Explanation of symbols]

[0062] 5 Electric wire 7 Printing 10 Printing equipment for electric wires 20. Conveyor 30 Inkjet head 40 Drying equipment 50 Guide pipe (cylindrical member) 51 Insertion hole 51d Inlet opening (opening) 51e Electric wire exit 52 Air supply port (supply port)

Claims

1. an inkjet head that prints on the electric wire by ejecting ink; a conveying device that conveys the electric wire in a longitudinal direction of the electric wire; a drying device that is provided downstream of the inkjet head in a conveying direction of the electric wire and that blows air onto a printed portion of the electric wire, The drying device includes a cylindrical member provided to surround a periphery of a transport path of the electric wire, An internal space through which the electric wire passes is defined inside the cylindrical member, The cylindrical member is a large diameter portion defining an upstream side of the internal space in a conveying direction of the electric wire; a small diameter portion that defines a downstream side of the internal space in a conveying direction of the electric wire and has a cross-sectional area smaller than that of the large diameter portion; a tapered portion that defines an intermediate portion between the large diameter portion and the small diameter portion in a transport direction of the electric wire in the internal space and has a cross-sectional area that decreases toward the small diameter portion; a supply port that opens to the large diameter portion and through which compressed air is supplied, the large diameter portion is provided at an upstream end in a transport direction of the electric wire, and includes an inlet opening into which the electric wire is inserted and from which compressed air is discharged, the small diameter portion includes a wire outlet provided at a downstream end in a transport direction of the wire, from which the wire exits, The opening area of ​​the wire outlet is smaller than the opening area of ​​the inlet opening. Printing equipment for electric wires.

2. The conveying device is configured to convey the electric wire while the drying device is blowing air onto the printed portion of the electric wire.

2. The wire printing device according to claim 1.

3. The supply port penetrates the tubular member in a direction intersecting the longitudinal direction of the electric wire.

3. The wire printing device according to claim 1 or 2.

4. The supply port is provided so as to be offset from a transport path of the electric wire when viewed in a penetration direction of the supply port.

4. The wire printing device according to claim 3.

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