JP2007069591A - Mold apparatus for helical gear and molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold apparatus, which can return the piece for forming the tooth part to a predetermined phase position and position it by utilizing the clamping operation of the mold, without the need for any special apparatus, by a positioning means prepared only in the movable side, by an inexpensive and simple structure not subject to the restriction of the shape of a molded product, and to provide the molded product constant in the phase position. <P>SOLUTION: In the mold apparatus for forming a helical gear in which a piece 3 for forming the tooth part rotates upon the mold release, the apparatus makes the piece rotate in the direction opposite to that at the mold release by utilizing the clamping operation of the mold upon the mold clamping, returns the piece 3 to the predetermined phase position, and also positions it. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical gear molding die apparatus used for manufacturing a helical gear that can be used in a driving device of an image forming apparatus such as a copying machine or a printer.

In a mold apparatus for forming a general helical gear, mold release is performed by rotating a piece forming a tooth portion. Therefore, the phase position of the tooth portion is different for each forming (for example, Patent Document 1). And 2).
In such a mold apparatus for forming a helical gear, the position in the rotation direction of the piece forming the tooth portion at the time of continuous forming starts from the position after the immediately preceding rotation operation and rotates every time the mold is released. The position of the piece that forms the tooth portion is different for each molding, and therefore the phase position of the tooth portion of the helical gear is different for each molding.
Patent Document 1 discloses that a cylinder means is used as a piece positioning method, and Patent Document 2 which has the same disclosure does not have a mechanism for returning the phase position of a piece. As a method for making the phase position of the tooth portion constant in the prior art, there is a method of releasing the mold while fixing the piece forming the tooth portion and rotating the molded product. Because of the rotation, the shape other than the teeth is restricted.
For example, the web cannot be provided with ribs that extend radially from the center hole. Alternatively, in order to obtain such a shape, it is necessary to provide the mold apparatus with a mechanism for pre-cutting the web shape portion piece. In this case, the mechanism of the mold apparatus becomes complicated and expensive.
FIG. 9 is a schematic sectional view showing an example of a configuration in which the phase position of the tooth portion is made constant. As another method for making the phase position of the tooth part constant, as shown in FIG. 9, a positioning pin 22 on the fixed side 21 (or a piece that forms the movable side tooth part), and a piece 20 that forms the movable side tooth part. There is a method of positioning the position of the piece 20 forming the tooth portion by providing the hole 23 on the (or fixed side) and inserting the positioning pin 22 into the hole 23 at the time of clamping.
In this case, since high positioning accuracy is required, it is difficult to manufacture the mold, and the cost becomes high, and problems such as galling occur when the positioning pin 22 is inserted into the hole 23. was there.
JP 2001-150498 A JP 2003-276061 A

In addition, there is a method of positioning a piece that forms a tooth portion using the cylinder device as described in Patent Document 1 described above, but in this case, the mold becomes expensive because the cylinder device is installed, and the molding process is also performed. In some cases, the operation time of the cylinder device is added, so that the molding cycle becomes long.
Therefore, an object of the present invention is to use a mold clamping operation, without requiring a special device, and by positioning means provided only on the movable side, the shape of the helical gear as a molded product is not limited. Another object of the present invention is to provide a molding die device capable of returning and positioning a piece forming a tooth portion with a simple structure at a low cost and positioning, and a molded product having a constant phase position.

In order to solve the above problems, the invention according to claim 1 forms the tooth portion of the helical gear when the helical gear, which is a molded product that has been molded in the mold, is projected in the mold release direction. In the molding die device of the Hasuba gear that rotates in a direction intersecting the mold release direction, the piece rotates in the opposite direction to the mold release using the mold clamping operation when clamping. The frame is configured to return to a predetermined phase position and to be positioned.
According to a second aspect of the present invention, in the first aspect, the piece is returned to and positioned at a plurality of different predetermined phase positions at the time of the mold clamping.
A third aspect of the invention is characterized in that, in the first or second aspect, a predetermined phase position for returning and positioning the piece can be adjusted.
A fourth aspect of the invention is characterized in that a molded product formed using the helical gear molding apparatus of the first to third aspects is a helical gear having a constant phase position.
The fifth aspect of the present invention is that the plurality of helical gears formed using the helical gear molding apparatus according to any one of the first to third aspects are different only in their phase positions, and other gear specifications and tooth portions. The other shape parts are the same.

  According to the present invention, no special device is required, and the positioning means provided only on the movable side is not limited by the shape of the molded product, and the piece for forming the tooth portion with a simple structure at a low cost is provided. It is possible to achieve a molding die apparatus that can return and position the phase position, and a molded product having a constant phase position.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a top view showing a state at the time of mold clamping of the molding die apparatus (only on the movable side) in the present invention. FIG. 2 is a cross-sectional view showing a state at the time of mold clamping of the molding die apparatus (only the movable side) in the present invention.
This embodiment is a mold apparatus for forming a molded product 10 as a helical gear, which will be described later, and the tooth portion of the helical gear is transferred and formed by the piece 3.
A characteristic configuration of the present invention is that when the helical gear 10 that is a molded product that has been molded in the mold is protruded in the mold release direction, the piece 3 that forms the tooth portion of the helical gear has the mold release direction. In a molding die apparatus for helical gears that rotate in the intersecting direction, the piece 3 is rotated in the direction opposite to that at the time of mold release by using the mold clamping operation at the time of clamping, and the piece is moved to a predetermined phase position. It is in the point comprised so that it might return and position.
The positioning rod 1 with its lower end fixed to the ejector plate 2 extends upward through the movable side plate 9 and enters the groove 6 of the piece 3 forming the tooth portion, and the tip of the positioning rod 1 (expanded in a wedge shape). The inclined surface 1a of the opened portion is in contact with the alignment portion 4 that is provided in the upper portion of the groove portion 6 of the piece 3 and is expanded in a tapered shape. The angle a of the inclined surface of the alignment portion 4 is set so that a> β is satisfied with respect to the torsion angle β of the tooth portion of the helical gear which is a molded product. Here, the alignment part 4 is comprised from the abutting surface 1a of the positioning rod 1 and the abutting surface 3a of the piece 3 which forms a tooth | gear part so that it may become clear from FIG. 3 mentioned later.
It is necessary to provide a gap b between the side surface of the positioning rod 1 below the alignment portion 4 and the inner wall of the groove portion 6 of the piece 3. Further, when the back surface portion 5 of the groove portion 6 eliminates the gap between the ejector rod 1 and the piece 3 that forms the tooth portion and is in a sliding state, the piece 3 that forms the tooth portion moves away from the alignment portion 4. It becomes a rotation stop.
Alternatively, when it is necessary to provide a gap in the back surface portion 5 of the alignment portion 4 for some reason, the piece 3 forming the tooth portion is urged by the spring 19 or the like in the rotational direction approaching the alignment portion 4 with the positioning rod 1. If this is done, the positioning portion 4 will be in a state of abutment reliably (the piece 3 forming the tooth portion rotates forward and backward in the direction of the arrow in FIG. 1).
This is achieved, for example, by urging the piece 3 forming the tooth portion with the spring 19 in the direction in which the abutting surface 3a abuts against the abutting surface 1a of the positioning rod 1, as schematically shown in FIG. Is done.

FIG. 3 is a schematic sectional view showing a state in the middle of mold release of the molding die apparatus according to the present invention. As the ejector plate 2 moves in the mold release direction 7, the piece 3 forming the tooth portion rotates and moves in the direction of the arrow while protruding the molded product 10. The moving amount at this time is c1.
Here, since the molded product 10 is a helical gear, when the molded product 10 is about to come out of the mold, the molded product 10 needs to rotate the piece 3 for transferring and forming the tooth portion. When the helical gear is a molded product, the mold is created so that this operation is possible. That is, by rotating the piece 3 with respect to the release direction 7, the tooth portion of the helical gear is easily released from the transfer surface of the piece 3.
FIG. 4 is a schematic cross-sectional view showing a state at the completion of mold release of the molding die apparatus according to the present invention. The moving amount in the rotation direction of the piece 3 forming the tooth portion at this time is defined as c2. The gap b in FIG. 1 is set in advance so that b> c2. As the ejector plate 2 and the positioning rod 1 are lifted and the piece 3 formed by the tooth portion rotates as described above, the molded product (Hasuba gear) 10 is ejected while rotating.

FIG. 5 is a schematic cross-sectional view showing a state in the middle of clamping of the molding die apparatus according to the present invention.
As the ejector plate 2 moves in the mold clamping direction 8, the piece 3 rotates in contact with the abutting surface 1 a of the positioning rod in the alignment portion 4, returns to a predetermined phase position, and enters the state shown in FIG. 2.
FIG. 6 is a schematic sectional view showing another embodiment of the piece forming the tooth portion in the present invention. In this embodiment, the piece 11 forming the tooth portion is provided with a plurality of groove portions 11a. In accordance with the phase position of the molded product to be obtained, the positioning rod 1 is installed in one of the plurality of grooves 11a, and molding is performed.
According to this embodiment, it is possible to provide a helical mold device for helical gears that can return and position the piece 11 forming the tooth portion to a plurality of different predetermined phase positions using the same molding device. A plurality of molded products (Husuba gears) can be obtained in which only the phase position is different and the other gear specifications and the shape parts other than the tooth parts are the same.

FIG. 7 is a schematic cross-sectional view showing a state before adjustment of another embodiment of the molding die apparatus according to the present invention. FIG. 8 is a schematic cross-sectional view showing a state after adjustment of another embodiment of FIG. An adjustment rod 13 is disposed so as to pass from the ejector plate 12 through the movable plate 14.
The ejector plate 12 is formed with a female threaded portion that is screwed with a male threaded portion on the outer periphery of the adjustment rod 13. By the presence of these screws 15, the ejector plate 12 is clamped by rotating the adjustment rod 13. Can be adjusted. At this time, the adjustment rod 13 also serves as a return pin (not shown), so there is no need to provide a special return pin.
In the state after adjustment in which adjustment is performed as shown in FIG. 8 with respect to the state before adjustment in FIG. 7, a predetermined phase position (arbitrary constant position) of the piece 3 forming the tooth portion at the time of mold clamping In accordance with the adjustment amount d, the adjustment rod 13 is turned to adjust the fluctuation amount e of the position of the ejector plate 12 during mold clamping.
Therefore, it is possible to adjust the predetermined phase position of the piece 3 forming the tooth portion later, and it is possible to obtain a molding die apparatus that makes it easy to quickly start up the mold and ensure the quality of the predetermined phase position of the molded product.

It is a top view which shows the state at the time of the mold clamping of the shaping die apparatus (only a movable side) in this invention. It is sectional drawing which shows the state at the time of the mold clamping of the shaping die apparatus (only movable side) in this invention. It is a schematic sectional drawing which shows the state in the middle of mold release of the shaping die apparatus in this invention. It is a schematic sectional drawing which shows the state at the time of mold release completion of the shaping die apparatus in this invention. It is a schematic sectional drawing which shows the state in the middle of the mold clamping of the shaping die apparatus in this invention. It is a schematic sectional drawing which shows another embodiment of the piece which forms the tooth | gear part in this invention. It is a schematic sectional drawing which shows the state before adjustment of another embodiment of the shaping die apparatus in this invention. It is a schematic sectional drawing which shows the state after adjustment of another embodiment of FIG. It is a schematic sectional drawing which shows the example of the structure which makes the phase position of a tooth | gear part constant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positioning rod 1a Abutting surface 2 Ejector plate 3 Piece which forms tooth part 3a Abutting surface 4 Positioning part 5 Rear part of positioning part 6 Groove part 7 Moving direction of ejector plate (at the time of mold release)
8 Moving direction of ejector plate (when clamping)
10 Molded product (Hasuba gear)
11 Pieces forming teeth 11a Groove portion 12 Ejector plate 13 Adjustment rod 19 Spring a Angle of alignment portion b Clearance c1 Movement amount of piece (in the middle of mold release)
c2 Movement amount of piece (release completed)
d Phase position adjustment amount e Ejector plate position fluctuation amount

Claims (5)

  Molding of a helical gear, in which a piece forming the tooth portion of the helical gear rotates in a direction intersecting the releasing direction when the helical gear, which is a molded product that has been molded in the mold, is projected in the releasing direction. In the mold apparatus, when the mold is clamped, the mold is rotated in the direction opposite to that when the mold is released using the mold clamping operation, and the piece is returned to a predetermined phase position and positioned. A helical mold device for a helical gear.   2. The helical mold apparatus for a helical gear according to claim 1, wherein at the time of clamping, the frame is returned to and positioned at a plurality of different predetermined phase positions.   3. A molding die device for a helical gear according to claim 1, wherein a predetermined phase position for returning and positioning the piece is adjustable.   A molded product formed using the helical gear molding die device according to claim 1, wherein the molded product is a helical gear having a constant phase position.   The plurality of helical gears formed by using the helical gear forming die device according to claim 1 are different only in phase positions, and other gear specifications and shape parts other than tooth parts are the same. A molded product characterized by being.

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