Coil spring and pin holding structure and inkjet recording device equipped with same

Abstract

To provide a holding structure of a coil spring and a pin which can insert the pin easily to an internal part of the coil spring and can hold the pin in the insertion state, and to provide an inkjet recording apparatus including the holding structure of the coil spring and the pin.SOLUTION: A holding structure of a coil spring and a pin holds the coil spring and the pin to be inserted to the coil spring in the insertion state. The coil spring includes a main body part into which the pin is inserted and a pin insertion part of which one winding portion is formed on one end part of the main body part of an upstream side in the insertion direction of the pin so as to guide a tip part of the pin to the main body part. The pin insertion part includes a guide part which is protruded to the radial direction outer side than the main body part and a pin fixation part which is formed on a position opposite to a radial direction with respect to the guide part. The main body part has a first portion of the opposite side to the pin fixation part with respect to a center axis of the main body part and a second portion of the same side with the pin fixation part. The pin fixation part is formed on the radial direction inner side than the second portion, and an interval in a radial direction between the pin fixation part and the first portion is smaller than an outer diameter of the pin.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a holding structure for a coil spring and a pin used in electronic devices such as image forming devices. [Background technology]

[0002] In electronic devices such as image forming devices, when multiple components are fixed using fixing pins (screws), a coil spring may be inserted onto the pin and one component may be fixed in a state in which it is biased against the other component by the biasing force of the coil spring.

[0003] The configuration of fitting a coil spring to a pin is also used in probe pins. Probe pins are attached to connection jigs such as IC sockets or probe cards to establish electrical continuity with electrodes of electronic devices, and electrical connections are made by contacting the probe pins with multiple electrodes of the electronic device to be measured.

[0004] For example, Patent Document 1 discloses a contact for a probe pin, in which an upper contact and a lower contact have a guide portion at a first end side that engages with one end of the coil spring and a claw-shaped hook at a second end side for holding the other end of the coil spring, and the coil spring is held between the guide portion and the claw-shaped hook. The probe pin is formed by inserting the upper contact and the lower contact into the coil spring with their respective contacts facing in opposite directions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-232181 A Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally, in order to prevent the coil spring from coming off the pin, one end of the coil spring is machined into a D-shape, and the pin is pressed into the D-shaped portion to prevent the coil spring from falling off the pin. However, as the wire diameter of the coil spring increases, the coil spring becomes harder and the D-shaped portion becomes more difficult to deform. Therefore, if the pin is securely held by the D-shaped portion while taking into account the component tolerances of the coil spring and the pin, it becomes even more difficult to press in the pin, which reduces the ease of assembly. On the other hand, if the D-shaped portion is widened to take into account the ease of assembly, there is a problem that the coil spring falls off the pin.

[0007] In view of the above problems, the present invention aims to provide a coil spring and pin holding structure that allows a pin to be easily inserted inside the coil spring and can hold the pin inserted in the coil spring, and an inkjet recording device equipped with the same. [Means for solving the problem]

[0008] In order to achieve the above object, a first configuration of the present invention is a coil spring and pin holding structure that holds a coil spring and a pin inserted into the coil spring in an inserted state. The coil spring has a main body and a pin insertion part. The main body is inserted with a pin. The pin insertion part is formed by one turn at one end of the main body, which is upstream of the pin insertion direction, and guides the tip of the pin into the main body. The pin insertion part has a guide part and a pin fixing part. A circumferential part of the guide part protrudes radially outward from the main body. The pin fixing part is formed at a position facing the guide part in the radial direction. The main body has, in the first turn adjacent to the pin insertion part, a first part on the opposite side to the pin fixing part with respect to the central axis of the main body, and a second part on the same side as the pin fixing part. The pin fixing part is formed radially inward from the second part. The radial distance between the pin fixing part and the first part in a state where no external force is applied is smaller than the outer diameter of the pin. Effect of the Invention

[0009] According to the first configuration of the present invention, by forming a guide portion that protrudes radially outward in the pin insertion portion of the coil spring, the pin can be smoothly inserted into a coil spring with a thick wire diameter simply by tilting the pin toward the guide portion when inserting it into the pin insertion portion of the coil spring. Also, since the pin is sandwiched between the first turn of the main body and the pin fixing portion, it is possible to prevent the coil spring from coming off the pin. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a printer 100. [Diagram 2] A plan view of a recording unit 9 included in the printer 100. [Diagram 3] FIG. 1 is an enlarged view of the recording head 17b and its surroundings of the head unit 50 arranged in the recording section 9. [Figure 4] FIG. 1 is a side cross-sectional view of a connection portion between a recording head 17b and a head unit 50 taken in a direction perpendicular to the longitudinal direction. [Diagram 5] 1 is a perspective view of the head fixing spring 70 as seen from the side where the head fixing pin 60 is inserted. [Figure 6] A front view of the head fixing spring 70 as seen from the side where the head fixing pin 60 is inserted. [Figure 7] FIG. 1 is a side view showing a state in which the screw portion 65 of the head fixing pin 60 is inserted into the pin insertion portion 73 of the head fixing spring 70. [Figure 8] 1 is a perspective view showing a state in which the head fixing pin 60 is inserted into the main body 71 of the head fixing spring 70. [Figure 9] FIG. 9 is a partially enlarged view of the vicinity of the pin insertion portion 73 in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a schematic configuration of a printer 100 equipped with a coil spring and pin holding structure of the present invention. The printer 100 is equipped with a paper feed cassette 2 which is a paper storage section. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Inside the paper feed cassette 2, paper P, which is an example of a recording medium, is stored.

[0012] A paper feeder 3 is disposed downstream of the paper feed cassette 2 in the paper transport direction, i.e., above the right side of the paper feed cassette 2 in Fig. 1. The paper feeder 3 separates and sends out the paper P one by one toward the upper right of the paper feed cassette 2 in Fig. 1.

[0013] The printer 100 has a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner, which is the paper feed direction, of the paper feed cassette 2. The paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0014] A pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first transport unit 5 and a recording unit 9 are arranged immediately downstream in the paper transport direction of the pair of registration rollers 13. The paper P sent out from the paper feed cassette 2 passes through the first paper transport path 4a and reaches the pair of registration rollers 13. The pair of registration rollers 13 corrects skewed feed of the paper P and sends out the paper P towards the first transport unit 5 in time with the ink ejection operation performed by the recording unit 9.

[0015] The paper P sent to the first transport unit 5 by the registration roller pair 13 is transported by the first transport belt 8 to a position facing the recording section 9 (particularly recording heads 17a to 17c described below). An image is recorded on the paper P by ejecting ink from the recording section 9 onto the paper P. The ejection of ink in the recording section 9 is controlled by a control device 110 inside the printer 100.

[0016] In the paper transport direction, a second transport unit 12 is disposed downstream of the first transport unit 5 (on the left side in FIG. 1). The paper P on which an image has been recorded by the recording unit 9 is sent to the second transport unit 12. The ink ejected onto the surface of the paper P is dried while passing through the second transport unit 12.

[0017] In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side surface of the printer body 1. The paper P from which the ink has been dried by the second transport unit 12 is sent to the decurler unit 14, where any curls in the paper P are straightened out.

[0018] In the paper transport direction, a second paper transport path 4b is provided downstream of the decurler unit 14 (upper in FIG. 1). If double-sided recording is not performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged to a paper discharge tray 15a provided outside the left side of the printer 100. A sub-discharge tray 15b is provided below the paper discharge tray 15a to discharge unnecessary paper P (broken paper) that has experienced printing defects or the like.

[0019] A reversing transport path 16 for double-sided recording is provided at the top of the printer body 1, above the recording unit 9 and the second transport unit 12. When double-sided recording is performed, after recording on one side (first side) of the paper P is completed and the paper P passes through the second transport unit 12 and the decurler unit 14, it is sent to the reversing transport path 16 via the second paper transport path 4b.

[0020] After being sent to the reversing transport path 16, the transport direction of the paper P is then switched so that recording can be performed on the other side (second side) of the paper P. The paper P then passes over the top of the printer body 1 and is transported to the right side, passes through the pair of registration rollers 13, and is sent again to the first transport unit 5 with the second side facing up. In the first transport unit 5, the paper P is transported to a position facing the recording section 9, and an image is recorded on the second side by ink ejection from the recording section 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler section 14, and the second paper transport path 4b in that order, and is discharged to the paper discharge tray 15a.

[0021] In addition, a maintenance unit 19 and a cap unit 20 are disposed below the second transport unit 12. The maintenance unit 19 moves horizontally below the recording unit 9 when performing purging, wipes off ink extruded from the ink ejection ports of the recording head, and collects the wiped ink. Purging refers to the operation of forcibly pushing out ink from the ink ejection ports of the recording head in order to expel thickened ink, foreign matter, and air bubbles from the ink ejection ports. The cap unit 20 moves horizontally below the recording unit 9 when capping the ink ejection surface of the recording head, and then moves further upward to be attached to the underside of the recording head.

[0022] 2 is a plan view of the recording unit 9. The recording unit 9 includes a head housing 10 and line heads 11Y, 11M, 11C, and 11K. The line heads 11Y to 11K are held in the head housing 10 at a height that forms a predetermined gap (for example, 1 mm) with respect to the conveying surface of an endless first conveyor belt 8 that is stretched around a plurality of rollers including a drive roller 6a, a driven roller 6b, and a tension roller (not shown). The drive roller 6a drives the first conveyor belt 8 in the conveying direction of the paper P (the direction of the arrow A).

[0023] Each of the line heads 11Y to 11K has a plurality of (three in this example) recording heads 17a to 17c. The recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (arrow BB' direction) perpendicular to the paper transport direction (arrow A direction). The recording heads 17a to 17c have a plurality of ink ejection openings 18 (nozzles). The ink ejection openings 18 are arranged at equal intervals in the width direction of the recording head, that is, the paper width direction (arrow BB' direction). From the line heads 11Y to 11K, inks of yellow (Y), magenta (M), cyan (C), and black (K) are ejected toward the paper P transported by the first transport belt 8 through the ink ejection openings 18 of the recording heads 17a to 17c.

[0024] Fig. 3 is an enlarged view of the vicinity of the recording head 17b of the head unit 50 arranged in the recording section 9. Fig. 4 is a side cross-sectional view (cross-sectional view taken along the CC' arrow in Fig. 3) of the connecting portion between the recording head 17b and the head unit 50 cut in a direction perpendicular to the longitudinal direction. The recording heads 17a to 17c are each individually detachable from a unit frame 51 constituting the head unit 50. More specifically, a head mount member 53 is fixed to the unit frame 51, and both left and right ends of a head side frame 55 constituting each of the recording heads 17a to 17c are fastened to the head mount member 53 by a head fixing pin 60.

[0025] 4, a head fixing pin 60 is fastened to a screw hole 53a of the head mount member 53, passing through a long-hole-shaped head positioning hole 55a formed in the head side frame 55. A head fixing spring 70 is sandwiched between the head fixing pin 60 and the head side frame 55. As a result, the head side frame 55 is pressed against the head mount member 53 by the biasing force of the head fixing spring 70. In other words, the head side frame 55 is held by the head fixing pin 60 and the head fixing spring 70 so as to be movable in the horizontal direction relative to the unit frame 51, and the angles of the recording heads 17a to 17c can be adjusted by an angle adjustment mechanism (not shown).

[0026] Figures 5 and 6 are respectively a perspective view and a front view of the head fixing spring 70 as viewed from the insertion side of the head fixing pin 60. Figure 7 is a side view showing a state in which the screw portion 65 of the head fixing pin 60 is inserted into the pin insertion portion 73 of the head fixing spring 70. Figure 8 is a perspective view showing a state in which the head fixing pin 60 is inserted into the main body portion 71 of the head fixing spring 70. Figure 9 is an enlarged view of the vicinity of the pin insertion portion 73 in Figure 8. The holding structure of the head fixing pin 60 and the head fixing spring 70 will be described below with reference to Figures 5 to 9.

[0027] As shown in FIG. 8, the head fixing pin 60 has a shaft portion 61 and a head portion 63. The shaft portion 61 is a cylindrical portion that is inserted into the head fixing spring 70. In this embodiment, the outer diameter of the shaft portion 61 is 4 mm. The head portion 63 is a disk-shaped portion that is formed at one end of the shaft portion 61 and has a larger diameter than the shaft portion 61. The head portion 63 is formed with a groove shape 63a (see FIG. 4) with which a jig such as a screwdriver can be engaged. A threaded portion 65 is formed at the end of the shaft portion 61 opposite the head portion 63. The threaded portion 65 has a smaller diameter than the shaft portion 61, and is screwed into the screw hole 53a of the head mounting member 53.

[0028] The head fixing spring 70 is a coil spring made of elastic metal wire (spring material). As shown in Fig. 5 and Fig. 6, the head fixing spring 70 has a main body portion 71, a pin insertion portion 73, and a contact portion 75.

[0029] The head fixing pin 60 is inserted into the main body 71. The inner diameter of the main body 71 is larger than the outer diameter of the head fixing pin 60. In this embodiment, the inner diameter d1 of the main body 71 is 4.5 mm. At one end (the right end in FIG. 8) of the main body 71, which is upstream of the insertion direction of the head fixing pin 60, a pin insertion portion 73 that guides the tip of the head fixing pin 60 into the main body 71 is formed by one turn. The main body 71 has, at the first turn adjacent to the pin insertion portion 73, a first portion 71a on the opposite side to the pin fixing portion 73b with respect to the central axis O of the main body 71, and a second portion 71b on the same side as the pin fixing portion 73b (diametrically facing the first portion 71a).

[0030] The pin insertion portion 73 has a guide portion 73a and a pin fixing portion 73b. The guide portion 73a is a portion in which a circumferential part of the pin insertion portion 73 (a lower portion in Figs. 5 and 6) protrudes radially outward from the main body portion 71 (first portion 71a). The pin fixing portion 73b is a linear portion obtained by bending an end portion of the pin insertion portion 73 substantially vertically. The pin fixing portion 73b is formed at a position radially opposite to the guide portion 73a and radially inward from the second portion 71b. In this embodiment, the protrusion amount of the guide portion 73a relative to the main body portion 71 (first portion 71a) is 0.5 mm. In addition, the radial distance d2 between the guide portion 73a and the pin fixing portion 73b is 3.95 ± 0.2 mm, which is substantially the same as the outer diameter (4 mm) of the shaft portion 61 of the head fixing pin 60.

[0031] An abutment portion 75 having an outer diameter larger than that of the main body portion 71 is formed by one turn at the other end (the left end in FIG. 8) of the main body portion 71, which is downstream in the insertion direction of the head fixing pin 60. The abutment portion 75 abuts against the head-side frame 55 when the head-side frame 55 is fixed to the head mounting member 53 using the head fixing pin 60 and the head fixing spring 70, thereby preventing the head fixing spring 70 from fitting into the head positioning hole 55a.

[0032] When inserting the head fixing pin 60 into the head fixing spring 70, first, the tip portion (thread portion 65) of the head fixing pin 60 is inserted into the pin insertion portion 73. At this time, as shown in Fig. 7, the tip portion of the head fixing pin 60 is inserted obliquely from the guide portion 73a side (lower side in Fig. 7) with respect to the central axis O of the main body portion 71. This allows the tip portion of the head fixing pin 60 to be smoothly inserted into the main body portion 71 without interfering with the first portion 71a of the main body portion 71 adjacent to the guide portion 73.

[0033] 8 and 9, after inserting the screw portion 65 to a position beyond the pin insertion portion 73, the head 63 side of the head fixing pin 60 is lifted to make the shaft portion 61 parallel to the central axis O of the main body portion 71. In this state, the shaft portion 61 is pushed into the main body portion 71.

[0034] Here, the radial distance d3 between the pin fixing portion 73b and the first portion 71a of the main body portion 71 is 3.45±0.2 mm, which is smaller than the outer diameter of the shaft portion 61. Therefore, the shaft portion 61 is pressed into the main body portion 71 while elastically deforming the pin insertion portion 73 so as to push the pin fixing portion 73b upward.

[0035] Thereafter, the head 63 of the head fixing pin 60 is inserted to a position adjacent to the pin insertion portion 73 of the head fixing spring 70, completing the attachment of the head fixing spring 70 to the head fixing pin 60. The shaft portion 61 of the head fixing pin 60 is clamped between the first portion 71a and the pin fixing portion 73b of the main body portion 71 of the head fixing spring 70, and the attached state of the head fixing pin 60 to the head fixing spring 70 is maintained.

[0036] According to the configuration of this embodiment, by forming a guide portion 73a that protrudes radially outward in the pin insertion portion 73 of the head fixing spring 70, when inserting the head fixing pin 60 into the pin insertion portion 73 of the head fixing spring 70, the head fixing pin 60 can be smoothly inserted into the head fixing spring 70, which has a thick wire diameter, simply by tilting the head fixing pin 60 toward the guide portion 73a when inserting the head fixing pin 60 into the pin insertion portion 73 of the head fixing spring 70.

[0037] Furthermore, since the shaft portion 61 of the head fixing pin 60 is clamped between the first portion 71a of the main body portion 71 and the pin fixing portion 73b, the head fixing spring 70 can be prevented from coming off the head fixing pin 60.

[0038] In addition, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. For example, in the above embodiment, the end of the pin insertion portion 73 is bent substantially vertically to form a straight pin fixing portion 73b, but even if the pin fixing portion 73b is not formed straight, the shaft portion 61 of the head fixing pin 60 can be clamped between the first portion 71a of the main body portion 71. However, by forming the pin fixing portion 73b straight, the shaft portion 61 can be more firmly clamped between the first portion 71a.

[0039] Furthermore, the present invention is not limited to the inkjet recording printer 100 as shown in FIG. 1, but can also be applied to other image forming devices such as electrophotographic printers, copiers, and digital multifunction machines (which combine various functions such as copying, facsimile, and scanning, and are also called MFPs (Multi Function Peripherals)). [Industrial Applicability]

[0040] The present invention can be used in a coil spring and a holding structure for a pin inserted into the coil spring. By using the present invention, it is possible to provide a holding structure for a coil spring and a pin that allows the pin to be easily inserted into the coil spring and that can hold the pin inserted in the coil spring, and an inkjet recording device equipped with the same. [Explanation of symbols]

[0041] 17a~17c Recording head 18 Ink outlet (nozzle) 50 Head Unit 51 Unit Frame 55 Head side frame 60 Head fixing pin (pin) 61 Shaft 63 Head 65 Threaded part 70 Head fixing spring (coil spring) 71 Main body 71a Part 1 71b Part 2 73 Pin insertion part 73a Guide part 73b Pin fixing part 75 Contact part 100 Printers (inkjet recording devices) O center axis

Claims

1. A coil spring and pin holding structure that holds a coil spring and a pin inserted into the coil spring in an inserted state, The coil spring is a main body portion into which the pin is inserted; a pin insertion portion that is formed by one turn at one end of the main body portion on the upstream side in the insertion direction of the pin and that guides the tip end of the pin into the main body portion; having The pin insertion portion is A guide portion having a circumferential portion protruding radially outward beyond the main body portion; a pin fixing portion formed at a position radially opposed to the guide portion; having The main body has a first turn adjacent to the pin insertion portion. a first portion on an opposite side of the pin fixing portion with respect to a central axis of the main body; A second portion on the same side as the pin fixing portion; having The pin fixing portion is formed radially inward from the second portion, A coil spring and pin holding structure, characterized in that a radial distance between the pin fixing portion and the first portion when no external force is applied is smaller than an outer diameter of the pin.

2. 2. The coil spring and pin holding structure according to claim 1, wherein the pin fixing portion is formed into a straight line by bending an end of the pin insertion portion substantially vertically.

3. 3. The holding structure for a coil spring and a pin according to claim 1, wherein a radial distance between the guide portion and the pin fixing portion is substantially the same as an outer diameter of the pin.

4. a recording head having a plurality of nozzles for ejecting ink; a unit frame for holding the recording head; a head fixing pin as the pin for fixing a head side frame constituting the recording head to the unit frame; a head fixing spring as the coil spring into which the head fixing pin is inserted; Equipped with 4. An ink jet recording apparatus, comprising: a holding structure according to claim 1, for holding said head fixing pins and said head fixing springs in an inserted state.

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