JP2001018197A - Boring method for elastic body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boring method for an elastic body of an elastic roller, lengthening the service life of a boring tool and providing the elastic body with a through hole straight with the same cross-sectional shape in each longitudinal position and the finely machined inner surface. SOLUTION: After an elastic body W which is the material of an elastic roller is compressed in its longitudinal direction, a drill 5 is inserted into the elastic body W from one end face of the compressed elastic body W while rotating the drill 5. After projecting the drill 5 from the opposite side end face of the elastic body W, the drill 5 is pulled out of the elastic body W to reset the elastic body W into its original length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an elastic roller used as a paper supply roller or a toner supply roller of a copier or a printer, and the like, by drilling a hole for inserting a shaft into an elastic body. The present invention relates to a method for piercing an elastic body.

[0002]

2. Description of the Related Art A conventional example of a method of forming a through hole for inserting a shaft in an elastic roller is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 8-12699.
No. 7 is described.

[0003] In this publication, a hollow and prismatic box shape facing left and right is formed, and a hole is formed in the center of the right end face and the inside of the frame body is opened at the left end face. An elastic body such as a sponge rubber or urethane having a cross section similar to the cross section of the frame body, that is, a pressing member having the same cross section shape as the cross section shape of the frame body is packed with a work. The elastic body is pressed into the inside of the frame through the opening on the left side to compress the elastic body to about ３ to ／ of the original length.

Next, a thin cylindrical small-diameter blade having a circular edge at the left end and a left end at the right end face of the frame body is opened through a hole in the right end face thereof, and is rotated in the axial direction. While pressing against the center of the right end face of the elastic body, the straight body is rotated while rotating to the left end face of the elastic body.

After the small-diameter cylindrical blade reaches the left end face of the elastic body, when the cylindrical blade is pulled out of the elastic body, a small-diameter and circular through hole is formed in the center of the elastic body. Then, a large-diameter cylindrical blade that is the same diameter as the elastic roller to be manufactured is concentric with the traveling path of the cylindrical blade, from the right end surface to the left end surface of the elastic body. Rotate it straight while rotating, take out the hollowed-out piece from the elastic body with the large-diameter cylindrical blade from the inside of the large-diameter cylindrical blade, and elastically return it to its original length. Complete. Thereafter, the shaft is fitted into the through hole of the elastic roller.

[0006]

However, since the small-diameter cylindrical cutting tool is thin, if it is repeatedly used, the small-diameter cylindrical cutting tool may be used in a relatively short time due to the frictional resistance with the inside of the elastic body. Since the cylindrical blade is deformed, the life of the small-diameter cylindrical blade is short.

In addition, since the small-diameter cylindrical cutting tool is thin, it tends to be shaken inside the elastic body during grinding, so that the through-hole may not be formed in a straight line.

Further, while the small-diameter cylindrical blade is grinding the inside of the elastic body, a part of the elastic body taken into the inside of the cylindrical blade is twisted in the inside by the rotation of the cylindrical blade. As a result, a part of the elastic body in front of the cylindrical blade is caught inside the cylindrical blade, and when the cylindrical blade gradually advances in this state, the diameter of the completed through-hole increases toward the left side. Because it is large, it is difficult to keep the inside diameter constant.

Also, depending on the material of the elastic body, the frictional resistance with the cylindrical blade may increase. In such a case, the cylindrical blade must be lubricated beforehand in order to clean the inner surface of the through hole. An agent must be applied, and the operation of forming a through-hole is troublesome.

The present invention has been made in view of the above-mentioned problems of the prior art, and can extend the life of a drilling tool and provide an elastic body with high linearity and high roundness. Further, it is an object of the present invention to provide a method for piercing an elastic body with a small diameter variation and capable of forming a beautiful hole on the inner surface.

[0011]

According to the present invention, the above-mentioned problem is solved as follows. (1) After compressing the elastic body, drill the hole from one end face by inserting the drill in the compression direction while rotating, then pull out the drill from the elastic body and return the elastic body to its original length Let it.

(2) In the above item (1), the tip angle is about 6
Drill the elastic body using a 0 degree drill.

(3) In the above item (1) or (2),
An elastic body having substantially the same cross-sectional shape as the cross-sectional shape of the frame body is packed inside the cylindrical frame body, and a pressing member is inserted from one open end of the cylindrical frame body to compress the elastic body. And
The drill is inserted into the elastic body through the other end of the cylindrical frame.

(4) In the above item (3), the cross section of the hollow box-shaped frame is made non-circular.

(5) In the above item (3) or (4),
A pressing member is placed on a substantially horizontal plate, and a cylindrical frame filled with an elastic body is placed on the pressing member from above so that an opening end thereof faces downward. The elastic body is compressed by pushing down the frame.

(6) In the above item (5), the cylindrical frame body is pushed down by a vertically movable pressing means, and the boring operation is performed while maintaining the pressed state.

[0017]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

The elastic body (W) shown in FIG. 1 is a raw material of an elastic roller used as a paper feed roller or a toner supply roller of a copying machine, and is made of an elastic foam such as a prismatic urethane resin. ing. The elastic roller (R) described later is completed by working this elastic body (W) using an apparatus and equipment described below.

A substantially horizontal work plate (2) which forms part of the machine tool (1) of the machine tool shown in FIGS.
A pressing member (3) in the shape of a rectangular tube having a cross section substantially the same as that of the elastic body (W) is provided upright on the upper surface of the pressing member (3). As shown in FIG. At the center of the upper wall (3a) that closes the hole, there is provided a relief hole (4) through which the tip of a drill (5) described later can enter. (3b) is a mounting piece that bends the lower end of the pressing member (3) outward and horizontally and fixes it to the upper surface of the work plate (2).

Above the work plate (2) of the machine tool (1), a drill (5) that moves vertically by a lifting device (not shown) and a pair of left and right fluid pressure cylinders (the overall structure is not shown in the drawing) ) A pair of piston rods (6) extending downward from the lower end of the pair of piston rods (6) is supported so as to be substantially horizontal, and has a through hole (7) for passing a drill (5) in the center. A plate (8) is provided.

The drill (5) and the pressing plate (8) are always located considerably above the pressing member (3) (the state shown in FIG. 2), and the lifting device and the fluid pressure cylinder are operated downward to operate. Then, it descends to the vicinity of the work plate (2) (state of FIG. 3).

(9) The front part and the bottom part are open, and the front part of the box body (11) is attached to the front part of a hollow box body (11) having a through hole (10) formed in the upper surface. It is a frame body in which the front plate (12) to be closed is pivotally connected with two upper and lower hinges (13), and the front plate (12) is closed at the center of the left edge of the front plate (12) in the vertical direction. At this time, a fixture (14) for fixing the front plate (12) to the box (11) is attached. The cross-sectional shape of the inside of the frame (9) is substantially the same as that of the pressing member (3) and the elastic body (W), and the vertical dimension thereof is substantially the same as the length of the elastic body (W). . The vertical dimension of the pressing member (3) is about ／ of the vertical dimension of the frame (9).

The drill (5) is a so-called twist drill made of a super-hard alloy, the upper end of which is detachably attached to a chuck (15) provided at the lower end of an elevating device. As shown in Fig. 4, the tip angle (α)
Is formed at about 60 degrees. The edge of the torsion groove (5b) provided from the cutting edge (5a) at the tip to the upper end portion has a blade (5
c) is formed.

Next, using the above-described apparatus and equipment,
The procedure for manufacturing the elastic roller (R) from the elastic body (W) will be described.

First, the front plate (12) of the frame (9) is opened, and the elastic body
(W) is packed in the frame body (9), and the front plate (12) is closed, and then the front plate (12) is firmly fixed to the box body (11) by the fixing bracket (14) (see FIG. 2). ). Next, as shown in FIG. 3, the frame (9) is put on the upper surface of the pressing member (3), the piston rod (6) of the fluid pressure cylinder is extended downward, and the pressing plate (8) is attached to the frame ( 9) is pressed against the upper surface, and the lower surface of the frame (9) is
The piston rod (6) is extended until it comes into contact with
When the lower surface of (9) reaches the lower limit position where it contacts the work plate (2) (in this embodiment, the mounting piece (3a) of the pressing member (3)), the extension operation of the piston rod (6) is started. Stop and frame
Maintain the state where (9) is pressed down.

As shown in FIG. 3, when the frame (9) reaches the lower limit position, the elastic body packed inside the frame (9)
(W) has its length compressed to about 1/3 of its original length, and is considerably harder than its original state.

Then, by operating the lifting device,
The drill (5) is lowered while rotating, and the cutting edge (5) of the drill (5) is passed through the pressing plate (7) and the through holes (7) (10) of the box (11).
a) is pressed against the upper surface of the compressed elastic body (W) and drill
(5) is directly inserted into the elastic body (W). Drill
In (5), the cutting edge (5a) grinds the inside of the elastic body (W), and the inner surface of the hole formed by the cutting edge (5a) is cut by the blade (5c) at the edge of the torsion groove (5b). Elastic body (W) while further grinding
Go down the inside of. When the cutting blade (5a) penetrates the lower surface of the elastic body (W) and reaches the relief hole (4) of the pressing member (3), the lifting device is temporarily stopped, and then the drill (5) is moved upward by the lifting device. And the drill (5) is completely pulled out of the elastic body (W). Inside the elastic body (W) from which the drill (5) is pulled out, a circular through hole (1) penetrating the elastic body (W) in the vertical direction is provided.
6) is formed.

Thereafter, the piston rod (6) is shortened.
When the pressing plate (8) is lifted and returned to the original position (pulled up), the frame (9) is pressed against the pressing member (3) by the returning force of the compressed elastic body (W). To rise. Thereafter, when the operator completely removes the frame (9) from the pressing member (3) and pulls out the elastic body (W) from the inside of the frame (9), the elastic body (W) exerts its own elastic restoring force. As a result, the state shown in FIG. 5 is obtained.

As described above, the elastic body (W) having the through hole (16) formed at the center thereof is provided with the metal shaft through the through hole (16).
(S) is fitted, and then its surface is shaved by a grindstone or the like (not shown) to complete a cylindrical elastic roller (R) as shown in FIG.

As in the present embodiment described above, the drill
Through hole (16) in elastic body (W) for elastic roller (R) by (5)
When drilling, the drill (5) is strong in terms of strength, so even if it is used repeatedly, the drill (5) does not deform, and the life of the drill (5) is considerably long Becomes

Further, since the drill (5) is strong in strength, the drill (5) does not shake while grinding the inside of the elastic body (W), and can proceed straight inside the elastic body (W). (Especially, since the tip angle of the drill (5) of the present embodiment is an acute angle of about 60 degrees, the drill (5) can move straight inside the elastic body (W) without moving back and forth and up and down. If the tip angle is in the range of 60 to 90 degrees, almost the same straightness as in the case of 60 degrees can be obtained.)
When grinding the inside of the elastic body (W), the part in contact with the drill (5) inside the elastic body (W) is caught in the drill (5) and does not twist inside, so it is completed. The through hole (16) thus formed is straight, and its cross-sectional shape is the same at any position in the longitudinal direction.
Accordingly, when the shaft (S) is fitted into the through hole (16) and the elastic roller (R) is rotated around the axis of the shaft (S), the elastic roller (R) rotates without eccentricity, and the paper or the like is rotated. The toner (both not shown) can be fed in a stable state.

Also, a through hole ground by the cutting blade (5a)
Since the inner surface of (16) is further ground by the cutting edge (5c) of the twist groove (5b) of the drill (5), the through-hole (16) can be used without applying the sliding lubricant to the drill (5). The inner surface of) can be beautifully finished. If the twist angle of the drill (5) is 45 ° or more, the effect of finishing the inner surface of the through hole (16) can be further improved.

In this embodiment, the drill (5) is made of a super-hard alloy material.
The surface may be coated with titanium nitride or the like.

[0034]

(A) According to the first aspect of the present invention, since the drill is strong in strength, the drill does not deform even when used repeatedly for a considerable number of times, and the life of the drill is long. Become.

Further, since the drill does not shake during the grinding of the inside of the elastic body and proceeds straight inside the elastic body, it is possible to form a straight through hole in the elastic body. Also, when the drill grinds the inside of the elastic body, the part in contact with the drill inside the elastic body is caught in the drill and does not cause twisting inside, so the cross-sectional shape of the completed through hole is The shape is the same at any position in the longitudinal direction. Also, since the drill is strong in strength, it does not shake while grinding the inside of the elastic body, it can go straight inside the elastic body, and the drill grinds the inside of the elastic body At that time, the part in contact with the drill inside the elastic body is not caught in the drill and does not cause twisting inside, so the completed through hole is straight, and its cross-sectional shape is at any position in the longitudinal direction Also have the same shape. For this reason, when the shaft is fitted into the through hole and the elastic roller is rotated around the axis of the shaft, the elastic roller rotates without eccentricity and can feed paper and toner in a stable state.

Further, since the inner surface of the through hole formed by the cutting edge of the drill is further ground by the blade portion of the twist groove of the drill, even if the sliding lubricant is not applied to the drill,
The inner surface of the through hole can be beautifully finished.

(B) According to the second aspect of the present invention, since the tip angle of the drill is an acute angle of about 60 degrees, the drill does not shake inside the elastic body which is a relatively soft material.
It can proceed straight, and the resulting through-hole can be further straightened.

(C) According to the third aspect of the present invention, the elastic body is packed in a compressed state inside a frame having the same cross-sectional shape as the elastic body, and the pressure of the contact surface between the elastic body and the inside of the frame is compressed. , The elastic body itself can be prevented from rotating due to the rotation of the drill.

(D) According to the fourth aspect of the present invention, the rotation of the elastic body itself due to the rotation of the drill can be more reliably prevented.

(E) According to the fifth aspect of the present invention, the elastic body can be reliably compressed by a simple and inexpensive device.

(F) According to the sixth aspect of the present invention, by using the pressing means, the elastic body can be more easily compressed, and the elastic body can be reliably maintained in the compressed state. Can be performed more reliably and accurately.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of an elastic body in a state before being processed according to an embodiment of the present invention.

FIG. 2 is a front view showing a main part and a frame of the machine tool.

FIG. 3 is a front view showing a state in which a frame is put on a pressing member and an elastic body is drilled.

FIG. 4 is an enlarged view of a tip portion of the drill.

FIG. 5 is an enlarged perspective view of the perforated elastic body.

FIG. 6 is an enlarged perspective view showing a state where a shaft is fitted to the completed elastic roller.

[Explanation of symbols]

 (1) machine tool (2) work plate (plate) (3) pressing member (4) relief hole (5) drill (5a) cutting blade (5b) twist groove (5c) blade portion (6) piston rod (pressing means (7) Through-hole (8) Pressing plate (pressing means) (9) Cylindrical frame (10) Through-hole (11) Box (12) Front plate (13) Hinge (14) Fixing bracket (15) Chuck (R) Elastic roller (S) Shaft (W) Elastic body (α) Tip angle of drill

Claims (6)

[Claims] After the elastic body is compressed, a drill is drilled from one end face of the elastic body by inserting the drill in the compression direction while rotating, and thereafter, the drill is pulled out from the elastic body so that the elastic body has its original length. A method for piercing an elastic body, wherein 2. The method for piercing an elastic body according to claim 1, wherein the elastic body is pierced using a drill having a tip angle of about 60 degrees. 3. An elastic body having substantially the same cross-sectional shape as that of the frame body is packed in the inside of the cylindrical frame body, and a pressing member is fitted from one open end of the cylindrical frame body. The method according to claim 1 or 2, wherein the drill is inserted into the elastic body by compressing the elastic body and penetrating the other end of the cylindrical frame. 4. The method according to claim 3, wherein the cylindrical frame has a non-circular cross-sectional shape. 5. A pressing member is placed on a substantially horizontal plate, and a cylindrical frame filled with an elastic body is placed on the pressing member from above with its open end facing downward. 5. The method according to claim 3, wherein the elastic body is compressed by pushing down the cylindrical frame after the compression. 6. The method for piercing an elastic body according to claim 5, wherein the cylindrical frame body is pressed down by a vertically movable pressing means, and the piercing operation is performed while maintaining the pressed state.