JP2007298998A - Toner conveyance pipe and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner conveyance pipe of a three-dimensional complex shape excellent in dimensional accuracy and airtightness, and to provide a method for manufacturing the pipe. <P>SOLUTION: The toner conveyance pipe of a gooseneck shape used in an image forming apparatus is a joined body of a pipe body having a semitubular part along the lengthwise direction of the pipe in at least one location and at least one semitubular cover to be joined to the semitubular part, wherein the junctions of the pipe body and the semitubular cover are ultrasonically welded. The pipe body and the semitubular cover are formed by injection molding in such shapes that the joint surfaces of the pipe body and the semitubular cover are made nearly planar. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner conveying pipe used in an image forming apparatus and a manufacturing method thereof.

2. Description of the Related Art Image forming apparatuses such as copying machines, facsimile machines, and printers have a toner container attached therein to supply toner contained in the container to the developing unit of the image forming apparatus. To replenish the toner to the developing unit and collect and recycle the undeveloped toner, a toner conveying means provided with a conveying coil or the like inside a resin toner conveying pipe is used. Conventionally, as such toner conveying means, the driving means for rotating the conveying coil is configured to be able to rotate forward and backward, so that the toner in the toner conveying path can be conveyed even when the toner is conveyed from the lower side to the upper side of the pipe. There is one that prevents clogging (see Patent Document 1).
Further, the shape of the toner conveying pipe is not only a straight line as shown in Patent Document 1, but also a complicated shape in which both ends of the pipe are three-dimensionally twisted depending on the form of the image forming apparatus. There is a case. In this case, the parting line is three-dimensionally twisted, making it difficult to perform die-cutting, making molding by injection molding difficult. Therefore, molding is mainly performed by blow molding or the like.

Conventionally, in order to manufacture containers and the like that require airtightness as a joined body, the cylindrical toner container is divided into two semi-cylindrical parts as those to be joined using ultrasonic welding with excellent welding strength, Some of these are joined by ultrasonic welding (see Patent Document 2).
JP 2003-208021 A (paragraph [0023]) JP 2003-66702 A (paragraph [0006])

However, when the toner conveying hype is formed by blow molding, there is a problem that the dimensional accuracy is poor and the thickness uniformity cannot be ensured. This reduction in dimensional accuracy causes a problem that the toner cannot be accurately conveyed by a certain amount by the conveying coil. If the thickness of the pipe is not uniform, there is a problem that the conveying coil provided in the pipe comes into contact with the pipe wall surface, the rotational resistance increases, and an extra load is applied to the power of the conveying coil. Also, noise generated at the time of contact becomes a problem. In addition, there is a problem that the airtightness is inferior, for example, a hole is generated in a thin portion during molding.
In addition, since the joining surface is flat in the cylindrical toner container of Patent Document 2, the injection molding and ultrasonic welding of each part are easy, but the shape of the toner transport pipe is three-dimensionally complicated as described above. It may be shaped, and injection molding is usually difficult.

  SUMMARY An advantage of some aspects of the invention is that it provides a three-dimensional complicated shape toner conveyance hype excellent in dimensional accuracy and airtightness and a method for manufacturing the same.

The toner conveying pipe of the present invention is a curved pipe-shaped toner conveying pipe used in an image forming apparatus, and includes a pipe main body having a semi-tubular portion along at least one portion along the pipe length direction, It is a joined body with at least one semi-tubular lid joined to a tubular portion, and a joined portion between the pipe body and the semi-tubular lid is ultrasonically welded.
Further, the pipe body and the semi-tubular lid body are formed by injection molding so that a joint surface between the pipe body and the semi-tubular lid body is substantially flat.

The pipe main body having a semi-tubular portion and the semi-tubular lid joined to the semi-tubular portion are separately formed by injection molding or the like without forming the entire pipe at once by blow molding or the like. By joining, the pipe thickness and the like are constant with excellent dimensional accuracy.
Further, the pipe main body and the semi-tubular lid are formed in such a shape that the joint surface between the pipe main body and the semi-tubular lid is substantially flat, so that the toner conveying pipe has a three-dimensional complicated shape. The injection molding of each part and the ultrasonic welding thereof are easy and the productivity is excellent.

The ultrasonic welded section has a convex shape in which one is convex, the other is a concave shape that can be fitted into the convex convex portion, and the convex bottom end width of the convex shape is the concave bottom surface of the concave shape. It is characterized by being ultrasonically welded while being fitted in a shape larger than the width.
Further, at least one side surface of the concave concave inner surface has an inclined surface in a direction in which the concave bottom surface width is narrower than the concave upper surface width.

  As a cross-section of the welded portion to be ultrasonically welded, one is a convex shape, the other is a concave shape that can be fitted into the convex shape convex portion, and the convex shape leading end width is larger than the concave bottom surface width of the concave shape By being ultrasonically welded while being fitted in a large shape, the inner surface of the concave portion and the outer surface of the convex portion are heated and melted, and are ultrasonically welded to each other. For this reason, the welding surface becomes larger than a simple butting surface, and the toner conveying pipe is excellent in airtightness and welding strength after ultrasonic welding even if it is a tubular member joined with a plurality of divided bodies.

  The method for producing a toner conveying pipe according to the present invention comprises injection-molding a pipe body having a semi-tubular portion along the pipe length direction at least at one place, and at least one semi-tubular lid joined to the semi-tubular portion. And a step of ultrasonically welding the semi-tubular lid to the semi-tubular portion of the pipe body, and the step of ultrasonic welding is such that one of the cross sections of the joint is convex, The other side is a concave shape that can be fitted to the convex shaped convex portion, and at the time of fitting, the shape of the convex tip end width is larger than the concave bottom surface width of the concave shape, and ultrasonic welding is performed on the inner surface of the concave portion. It is a process to perform.

  The pipe is divided into a plurality of parts and manufactured by injection molding, so that the dimensional accuracy is excellent even if the shape is a three-dimensional complicated shape. In addition, the ultrasonic welding is a process of ultrasonic welding on the inner surface of the concave portion using a shape in which the convex tip end width of the convex shape is larger than the concave bottom surface width of the concave portion at the time of fitting. A toner conveying pipe having excellent strength can be obtained.

  The toner conveying pipe of the present invention is a curved pipe-shaped toner conveying pipe used in an image forming apparatus, and includes a pipe main body having a semi-tubular portion along at least one portion along the pipe length direction, It is a joined body with at least one semi-tubular lid body joined to the tubular portion, and the joint portion between the pipe body and the semi-tubular lid body is ultrasonically welded. Is constant.

  The method for producing a toner conveying pipe according to the present invention comprises injection-molding a pipe body having a semi-tubular portion along the pipe length direction at least at one place, and at least one semi-tubular lid joined to the semi-tubular portion. And a step of ultrasonically welding the semi-tubular lid to the semi-tubular portion of the pipe body, and the step of ultrasonic welding is such that one of the cross sections of the joint is convex, The other side is a concave shape that can be fitted to the convex shaped convex portion, and at the time of fitting, the shape of the convex tip end width is larger than the concave bottom surface width of the concave shape, and ultrasonic welding is performed on the inner surface of the concave portion. Therefore, even if the welding surface is a tubular member formed by joining a plurality of divided bodies, the air-tightness and welding strength after ultrasonic welding are increased. Excellent.

An embodiment of the toner conveying pipe of the present invention will be described with reference to FIG. FIG. 1A is an exploded perspective view of the toner transport pipe, and FIG. 1B is a perspective view of the assembled toner transport pipe.
The toner conveying pipe 1 has a curved pipe shape including a pipe body 2 having a semi-tubular portion 2a and a semi-tubular lid body 3 joined to the semi-tubular portion 2a. The pipe body 2 and the semi-tubular lid body. 3 is ultrasonically welded. Further, inside the toner transport pipe 1, a transport coil (not shown) that transports toner in the pipe is provided.
The pipe body 2 and the semi-tubular lid 3 may have any shape as long as the semi-tubular portion 2a of the pipe body 2 and the semi-tubular lid 3 are fitted to each other so that the toner conveying pipe 1 can be formed. In particular, as shown in FIG. 1A, a shape in which the joint surface 5 between the pipe body 2 and the semi-tubular lid 3 is close to a plane is preferable. By adopting such a shape, when the respective parts are molded by injection molding, the portion of the mold that is not forcibly removed is reduced and molding becomes easy.
Further, the shapes of both end portions 1a and 1b of the toner conveying pipe 1 are appropriately changed according to the hopper to be connected, the toner recovery portion, and the like. For example, as shown to Fig.1 (a), one end part opens the pipe cross section 1a, and the other end part provides the opening part 1b in the pipe side surface.

Next, another embodiment of the toner conveying pipe of the present invention will be described with reference to FIG. FIG. 2A is an exploded perspective view of the toner transport pipe in which both ends are twisted three-dimensionally, and FIG. 2B is a perspective view of the assembled toner transport pipe.
In the toner conveying pipe 1 having a three-dimensional complicated shape as shown in FIGS. 2 (a) and 2 (b), a semi-tubular portion 2a and 2b are separately provided in the pipe body 2, and each semi-tubular portion 2a is provided. And 2b are joined to the semi-tubular lids 3a and 3b by ultrasonic welding. Here, for the same reason as in the case of FIG. 1, it is preferable that the semi-tubular portions 2a and 2b have a shape in which the joint surfaces with the semi-tubular lids 3a and 3b are close to flat surfaces, respectively.
In the case of the shape as shown in FIGS. 2A and 2B, when the pipe body 2 and the semi-tubular lid are combined as a pair, the joint surface between the pipe body 2 and the semi-tubular lid 3 is twisted. Therefore, injection molding of each part and ultrasonic welding thereof are difficult. On the other hand, by forming two semi-tubular portions 2a and 2b on the pipe body 2 where the joint surface with the semi-tubular lid 3 can be substantially flat, ultrasonic welding is easily performed for each semi-tubular lid. Can be performed.

Further, the portion connected to the toner conveying pipe can be formed integrally with the pipe body 2. FIG. 3A is an exploded perspective view of a toner transport pipe provided with a hopper at one end, and FIG. 3B is a perspective view of the assembled toner transport pipe.
The toner conveying pipe 1 shown in FIGS. 3A and 3B is shown in FIGS. 1A and 1B except that a hopper 6 is integrally formed on the pipe body 2. It is the same as shown. According to the present invention, the toner conveying pipe is not integrally formed by blow molding or the like, but is separately formed by injection molding. Therefore, the hopper 6 and the like can be integrally formed with the pipe body 2. As a result, the airtightness between the pipe body 2 and the hopper 6 is excellent. For the same reason, it is also easy to provide the flange 7 and the like on the side surface of the pipe body 2.

Next, the joint portion of the toner conveying pipe 1 will be described with reference to FIG. 4A shows an AA enlarged cross-sectional view of the joint in FIG. 1, and FIG. 4B shows an B cross-sectional enlarged view of the joint before ultrasonic welding.
The cross section of the joint 4 to be ultrasonically welded is such that the cross section of the semicircular tubular lid 3 is a convex shape 3c, and the cross section of the semitubular portion 2a of the pipe body 2 is a concave shape 2c. The convex portion tip width D is larger than the concave bottom surface width d ₂ of the concave shape.
Specifically, concave 2c semi tubular portion 2a is, the inner surface 2d and 2e, is composed of a bottom surface of the recess 2f, the direction of the inclined surface 2g to narrow the upper inner width d ₁ of the concave portion on the inner surface 2d Have. By fitting the convex shape 3c to the concave shape 2c having the inclined surface 2g and applying ultrasonic vibration, the heat generated by the deformation distortion at the contact portion starts from the edge of the side surface 3d of the convex shape 3c and the inclined surface 2g. Occurs at 3d and 2h.
As a result, the semi-tubular portion 2a and the semi-tubular lid 3 of the pipe body 2 are welded tightly by ultrasonic welding between the side surface 3d of the convex shape 3c and the side surface 2h of the concave shape 2c, thereby conveying the toner. The airtightness of the pipe 1 and the welding strength of the ultrasonic welding part are improved.

The shape of the inclined surfaces 2g, inner width d ₁ of the concave portion is in narrow shape toward the bottom surface 2f direction, the angle α shown in FIG. 4 (b), is preferably in the range of 30 ° to 60 °. Further, in order to maintain the external shape of the product, the depth d ₄ of the concave 2c convex 3c than the length d _3, deep extent that surplus melt does not overflow. In particular, since the toner conveying pipe of the present invention is required to have high dimensional accuracy, it is preferable to have a depth that can maintain sufficient welding strength and does not completely overflow the excess melt during welding.
Convex shape. 3c, it is preferable to set the tip width D and shape remembering about 0.05mm clearance than the upper inner width d ₁ of the concave portion. By adopting such a shape, it is possible to correct the deformation or the like by pressing the pipe body 2 and the semi-tubular lid 3 by introducing the irregularities at the fitting tip before applying welding vibration. By applying welding vibration while holding the presser, it is possible to weld the entire circumference uniformly.
The inclined surface 2g may be on one side of the inner side 2d or the inner side 2e, or on both sides of the inner side 2d and the inner side 2e.

Next, a method for manufacturing a toner conveying pipe according to the present invention will be described with reference to the drawings.
(1) The pipe body 2 having the semi-tubular portion 2a and the semicircular tubular lid body 3 are each injection-molded using the synthetic resin composition. By dividing the pipe into a plurality of semi-tubular parts and performing injection molding, the dimensional accuracy is superior to the case of integral molding by blow molding. The joint part of the semi-tubular portion 2a of the pipe body 2 and the semicircular tubular lid body 3 is provided with an uneven shape as shown in FIG.
(2) The convex shape of the semi-tubular lid 3 and the concave shape of the semi-tubular portion 2a are fitted, pressurized while generating ultrasonic vibration, and press-fitted together. By this step, the side surface 3d of the convex shape 3c and the side surface 2h of the concave shape 2c are ultrasonically welded.
The ultrasonic welding conditions vary depending on the synthetic resin material, concave and convex shape, etc., but the amplitude of the ultrasonic vibration horn is 25 to 50 μm in the vertical direction of the concave and convex shape, and the frequency is 15 to 20 kHz. Further, it is preferable because it increases airtightness.

When a plurality of semi-tubular portions are provided on the pipe body, ultrasonic welding between the semi-tubular lid and the semi-tubular portion is performed as many times as necessary.
In addition, when a hopper, a flange, and the like are provided on the toner conveying pipe, they can be integrally formed at the time of injection molding of the pipe body 2.

  The toner conveying pipe of the present invention is suitable as a toner conveying pipe for use in an image forming apparatus such as a copying machine, a facsimile machine, and a printer because burrs do not occur and dimensional accuracy, welding strength, and air density are improved. .

1 is an exploded perspective view of a toner conveying pipe according to an embodiment of the present invention. FIG. 6 is an exploded perspective view of a toner conveying pipe according to another embodiment of the present invention. FIG. 6 is an exploded perspective view of a toner conveying pipe according to another embodiment of the present invention. FIG. 6 is a cross-sectional view of a joint portion of a toner transport pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toner conveyance pipe 2 Pipe main body 3 Semicircular tubular lid body 4 Joining part 5 Joining surface 6 Hopper 7 Flange

Claims (4)

A bent tube-shaped toner conveying pipe used in an image forming apparatus and provided with a hopper at one end of the pipe, the toner conveying pipe having a semi-tubular portion at least at one place along the pipe length direction. A pipe-shaped toner conveying pipe for use in an image forming apparatus, comprising: a pipe main body having at least one semi-tubular lid joined to the semi-tubular portion;
The toner transport pipe is a joined body of a pipe body having a semi-tubular portion at least at one place along the pipe length direction and at least one semi-tubular lid joined to the semi-tubular portion, The joint surface between the pipe body and the semi-tubular lid is formed by injection molding using a mold having a shape in which a parting line is twisted in a three-dimensional manner, and the pipe body and the semi-tubular lid are The joint part is ultrasonically welded, and the cross section of the joint part has a convex shape on one side, a concave shape that can be fitted to the convex part of the convex shape, and a tip width of the convex part of the convex shape. It is a shape larger than the concave bottom surface width of the concave shape, and has an inclined surface in a direction that makes the concave bottom surface width narrower than the concave top surface width on one side surface of the concave concave inner surface, and the other side surface It is a vertical direction to the fitting up and down direction of the uneven shape, Toner conveying pipe depth of the shape is equal to or deeper than the fitting length of the convex shape.   2. The toner conveying pipe according to claim 1, wherein there are a plurality of semi-tubular portions formed in the pipe body, and the semi-tubular lids are respectively joined to the semi-tubular portions. A method of manufacturing a curved pipe-shaped toner conveying pipe used in an image forming apparatus,
Injection-molding a pipe body having a semi-tubular portion at least at one location along the length of the pipe, and at least one semi-tubular lid joined to the semi-tubular portion; And the step of ultrasonic welding the semi-tubular lid,
The step of injection molding is a step of injection molding the pipe body and the semi-tubular lid in a shape in which the joining surface is a substantially flat surface in which the parting line is twisted three-dimensionally,
In the ultrasonic welding step, one of the cross sections of the joint portion is a convex shape, the other is a concave shape that can be fitted to the convex portion of the convex shape, and the tip end width of the convex shape is the concave shape. The concave bottom surface width of the concave shaped concave inner surface is one side of the concave concave inner surface, and the concave bottom surface width is narrower than the concave top surface width, and the other side surface is concave. A toner characterized in that it is a step perpendicular to the vertical direction of fitting, wherein the depth of the concave shape is deeper than the fitting length of the convex shape and ultrasonic welding is performed on the inner surface of the concave portion. A method for manufacturing a conveying pipe.   Before the ultrasonic welding step, the concave and convex ends of the pipe main body and the semi-tubular lid are fitted to correct deformation of both the pipe main body and the semi-tubular lid having a substantially flat shape. The method for producing a toner conveying pipe according to claim 3, wherein:

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