JP7613234B2 - Coil spring and pin holding structure and inkjet recording device equipped with same - Google Patents

Description

The present invention relates to a coil spring and pin holding structure used in electronic devices such as image forming devices.

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

The configuration of fitting a coil spring onto 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 the electrodes of electronic devices, and electrical connections are made by contacting the probe pins with multiple electrodes of the electronic device to be measured.

For example, Patent Document 1 discloses a contact for a probe pin, in which the coil spring is held between an upper contact and a lower contact, each of which has a guide portion at a first end that engages with one end of the coil spring and a claw-shaped hook at a second end for holding the other end of the coil spring. The probe pin is formed by inserting the upper contact and the lower contact into the coil spring with the contact facing in opposite directions.

JP 2011-232181 A

Conventionally, 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 less likely to deform. Therefore, if an attempt is made to securely hold the pin with the D-shaped portion while taking into account the component tolerances of the coil spring and pin, it becomes even more difficult to press in the pin, reducing assembly workability. On the other hand, widening the D-shaped portion to take assembly workability into consideration poses the problem that the coil spring will fall off the pin.

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 into the coil spring and can hold the pin inserted in the coil spring, and an inkjet recording device equipped with the same.

In order to achieve the above object, the 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 pin is inserted into the main body. The pin insertion part is formed for 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 when no external force is applied is smaller than the outer diameter of the pin.

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. In addition, 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.

FIG. 1 is a cross-sectional view showing a schematic configuration of a printer 100. A plan view of a recording unit 9 included in the printer 100. An enlarged view of the recording head 17b and its surroundings of the head unit 50 arranged in the recording section 9. 1 is a side cross-sectional view of a connection portion between the recording head 17b and the head unit 50 taken in a direction perpendicular to the longitudinal direction. FIG. 2 is a perspective view of the head fixing spring 70 as seen from the side where the head fixing pin 60 is inserted. A front view of the head fixing spring 70 as seen from the side where the head fixing pin 60 is inserted. 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. FIG. 13 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. FIG. 9 is a partial enlarged view of the vicinity of the pin insertion portion 73 in FIG. 8 .

Below, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the schematic configuration of a printer 100 equipped with a coil spring and pin holding structure of the present invention. The printer 100 has 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. Paper P, which is an example of a recording medium, is stored inside the paper feed cassette 2.

A paper feed device 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 feed device 3 separates and sends out the paper P one sheet at a time toward the upper right of the paper feed cassette 2 in FIG. 1.

The printer 100 has a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner of the paper feed cassette 2, which is the paper feed direction. 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.

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, the first transport unit 5 and the 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 the skewed feed of the paper P, timing it with the ink ejection operation performed by the recording unit 9, and sends the paper P towards the first transport unit 5.

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

In the paper transport direction, the 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.

In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side of the printer body 1. The paper P on 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.

In the paper transport direction, a second paper transport path 4b is provided downstream of the decurler unit 14 (upper in Figure 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 on the outside left side of the printer 100. Below the paper discharge tray 15a, a sub-discharge tray 15b is provided for discharging unnecessary paper P (damaged paper) that has experienced printing defects, etc.

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, the paper P is sent to the reversing transport path 16 via the second paper transport path 4b after recording on one side (first side) of the paper P has been completed and the paper P has passed through the second transport unit 12 and the decurler unit 14.

The paper P sent to the reversing transport path 16 then has its transport direction switched for recording 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 sent to the right side, and passes through the pair of registration rollers 13 before being 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 unit 9, and an image is recorded on the second side by ink ejection from the recording unit 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler unit 14, and the second paper transport path 4b in that order, and is discharged to the paper discharge tray 15a.

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

Figure 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 (e.g., 1 mm) with respect to the conveying surface of the endless first conveyor belt 8, which is stretched around multiple 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).

Each of the line heads 11Y to 11K has multiple (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 multiple ink ejection ports 18 (nozzles). The ink ejection ports 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, ink of each color, yellow (Y), magenta (M), cyan (C), and black (K), is ejected through the ink ejection ports 18 of the recording heads 17a to 17c toward the paper P transported by the first transport belt 8.

Figure 3 is an enlarged view of the recording head 17b and its vicinity of the head unit 50 arranged in the recording section 9. Figure 4 is a side cross-sectional view (cross-sectional view taken along the CC' arrow in Figure 3) of the connection 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 the unit frame 51 that constitutes the head unit 50. More specifically, a head mounting member 53 is fixed to the unit frame 51, and the left and right ends of the head side frames 55 that constitute each of the recording heads 17a to 17c are fastened to the head mounting member 53 by head fixing pins 60.

As shown in FIG. 4, a head fixing pin 60 is fastened to a screw hole 53a of the head mounting 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 mounting 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 that it can move horizontally relative to the unit frame 51, and the angle of the recording heads 17a to 17c can be adjusted by an angle adjustment mechanism (not shown).

Figures 5 and 6 are respectively a perspective view and a front view of the head fixing spring 70 as viewed from the side where the head fixing pin 60 is inserted. Figure 7 is a side view showing the state where 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 the state where 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.

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 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) into which a jig such as a screwdriver engages. 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 screws into the screw hole 53a of the head mounting member 53.

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

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 of the main body 71 (the right end in FIG. 8) that 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 for 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 of 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).

The pin insertion portion 73 has a guide portion 73a and a pin fixing portion 73b. The guide portion 73a is a circumferential portion of the pin insertion portion 73 (the lower portion in Figs. 5 and 6) that protrudes radially outward from the main body portion 71 (first portion 71a). The pin fixing portion 73b is a linear portion formed by bending the end of the pin insertion portion 73 substantially vertically. The pin fixing portion 73b is formed radially inward from the second portion 71b at a position radially opposite to the guide portion 73a. 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.

At the other end of the main body 71 (the left end in FIG. 8), which is downstream in the insertion direction of the head fixing pin 60, an abutment portion 75 having an outer diameter larger than that of the main body 71 is formed by one turn. The abutment portion 75 abuts against the head side frame 55 when the head side frame 55 is fixed to the head mount 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.

When inserting the head fixing pin 60 into the head fixing spring 70, first insert the tip (threaded portion 65) of the head fixing pin 60 into the pin insertion portion 73. At this time, as shown in FIG. 7, the tip 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 prevents the head fixing pin 60 from interfering with the first portion 71a of the main body portion 71 adjacent to the guide portion 73, and allows the tip of the head fixing pin 60 to be smoothly inserted into the main body portion 71.

Next, as shown in Figures 8 and 9, the screw portion 65 is inserted to a position beyond the pin insertion portion 73, and then 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.

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 pushed into the main body portion 71 while elastically deforming the pin insertion portion 73 so as to push the pin fixing portion 73b upward.

Then, 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, and the attachment of the head fixing spring 70 to the head fixing pin 60 is completed. 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 head fixing pin 60 is maintained attached to the head fixing spring 70.

According to the configuration of this embodiment, by forming a guide portion 73a that protrudes radially outward on 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 with a thick wire diameter simply by tilting the head fixing pin 60 toward the guide portion 73a.

In addition, 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, it is possible to prevent the head fixing spring 70 from coming off the head fixing pin 60.

Otherwise, 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 approximately 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.

The present invention is also applicable not only to the inkjet recording printer 100 shown in FIG. 1, but also 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)).

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 can hold the coil spring with the pin inserted, and an inkjet recording device equipped with the same.

17a to 17c: recording head; 18: ink ejection port (nozzle);
50 Head unit 51 Unit frame 55 Head side frame 60 Head fixing pin (pin)
61 Shaft portion 63 Head portion 65 Screw portion 70 Head fixing spring (coil spring)
71 Main body portion 71a First portion 71b Second portion 73 Pin insertion portion 73a Guide portion 73b Pin fixing portion 75 Contact portion 100 Printer (inkjet recording device)
O Central axis

Claims (4)

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. The coil spring and pin holding structure according to claim 1, characterized in that the pin fixing portion is formed in a straight line by bending the end of the pin insertion portion approximately vertically. The coil spring and pin holding structure according to claim 1 or 2, characterized in that the radial distance between the guide portion and the pin fixing portion is approximately the same as the outer diameter of the pin. 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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