JP2002254445A - Method for manufacturing cylindrical elastomer product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a cylindrical elastomer product enabling automation and suppressing damage or deformation. SOLUTION: A drawing-out apparatus 1 is constituted of an outer frame body 7 and a press rod 9. The outer frame body 7 is constituted of upper and lower frames 11 and 13. An elastomer 3 bas a cylindrical shape, and a shaft core 5 is allowed to pierce through the elastomer 3. When the elastomer 3 is charged in the outer frame body 7 along with the shaft core 5, the outer frame body 7 is closed. Whereupon, compressed air is ejected from front and rear jet orifices 25 and 33 and, then, a press rod 9 is advanced to push the shaft core 5 out of a front passage 17. At this time, since the front passage 17 has a diameter smaller than that of the elastomer 3, the front end surface of the elastomer 3 comes into contact with a stepped surface 21 to be prevented from moving. The shaft core 5 and the elastomer 3 generate positional shift gradually to be separated from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tubular elastic product such as a roller mounted on office equipment.

[0002]

2. Description of the Related Art Copiers, facsimile machines, printers, A
In office equipment such as a TM, rollers such as a paper feed roller and a transport roller are used. This roller is usually a cross-linked molded article of a rubber composition. In a general method of manufacturing a roller, first, a base rubber, a crosslinking agent, various additives and the like are kneaded,
A rubber composition is obtained. Next, a cylindrical long body is molded from this rubber composition by a known molding method such as an injection molding method. Next, a shaft core is inserted into the elongated body, and the surface of the elongated body is polished. Next, the long body is cut into a predetermined size to obtain a plurality of elastic bodies. Next, the shaft core is removed from the elastic body. The elastic body is subjected to a washing treatment or the like, and a roller as a cylindrical elastic body product is obtained.

Since the elastic body has low hardness and high flexibility, rough handling in the manufacturing process may damage the surface or reduce dimensional accuracy due to deformation. In particular, since a load is applied to the elastic body in the step of removing the shaft core, problems such as damage and deformation are likely to occur. For the purpose of suppressing such a problem, a method of removing the shaft core while blowing compressed air between the elastic body and the shaft core may be adopted.

[0004] However, the removal step by blowing the compressed air has to be performed manually, and there is a problem that the production efficiency of the rollers is significantly reduced due to this. Means using a pipe extracting device disclosed in Japanese Patent No. 2559667 and Japanese Patent Publication No. 7-96195 are also conceivable, but such a device is generally expensive. Further, in these pipe extracting devices, there is a possibility that the elastic body may be damaged.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and can be automated.
Moreover, it is an object of the present invention to provide a method for manufacturing a cylindrical elastic product in which damage and deformation are suppressed.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, according to the present invention, a cylindrical elastic body and a shaft penetrating the elastic body form a space capable of accommodating the elastic body. A cavity surface, a front passage located forward of the cavity surface and smaller in diameter than the elastic body and larger in diameter than the axis, a rear passage located rearward of the cavity surface, and a boundary between the cavity surface and the front passage A charging step of charging the outer frame body with a step surface located at the position, while blowing a pressurized fluid between the elastic body and the shaft core, fixing the front end of the elastic body at the step surface, and from the rear passage. And a separating step of separating the elastic body and the shaft core by extruding the shaft core from the front passage with the inserted pressing rod.

In this manufacturing method, the elastic body charged into the outer frame is positioned by the outer frame. On the other hand, the shaft core passes through the front passage by the pressing rod and is pushed out of the outer frame body. Thereby, the position of the elastic body and the position of the axis are gradually shifted. At this time, since the pressurized fluid is blown between the elastic body and the shaft core, both are separated smoothly. This separation operation is performed automatically without manual operation. Further, the elastic body after the separation is accommodated in the outer frame body, and furthermore, the elastic body has the pressing rod freely penetrated. Therefore, handling of the elastic body is easy, and subsequent steps can be automated.

Preferably, the pressurized fluid is jetted from both a front jet formed near the step surface of the outer frame and a rear jet formed near the front end of the pressing rod. Thereby, the separation between the elastic body and the shaft core is further smoothed.

Preferably, the manufacturing method further includes a removing step of removing the elastic body from the outer frame after the separating step. Then, the charging step, the separating step, and the removing step are achieved by continuous automatic control. This manufacturing method is extremely excellent in workability.

The improvement of the workability according to the present invention is particularly remarkable when one of the plurality of elastic bodies is inserted into the outer frame in a state where one of the shaft cores is penetrated.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The present invention will be described in detail based on preferred embodiments.

FIG. 1 is a partial cross-sectional view showing a sampling device 1 used in a manufacturing method according to an embodiment of the present invention, together with an elastic body 3 and a shaft core 5. Also, FIG.
FIG. 2 is a left side view illustrating the extracting device 1 of FIG. 1. The extraction device 1 includes an outer frame 7 and a pressing rod 9. The outer frame 7 includes an upper frame 11 and a lower frame 13. The elastic body 3 has a cylindrical shape, and the shaft core 5 penetrates the elastic body 3. In this figure, one shaft core 5 penetrates the six elastic bodies 3. The sides of the elastic body 3 are in close contact with each other.

The upper frame 11 and the lower frame 13 have substantially the same shape. The upper frame 11 and the lower frame 13 have a cavity surface 15 forming a columnar cavity, a front passage 17 located forward (left side in FIG. 1) of the cavity surface 15, and a rear surface behind the cavity surface 15. And a rear passage 19 located therein. When the upper frame 11 and the lower frame 13 are fastened, the front passage 17 has a smaller diameter than the elastic body 3 and a larger diameter than the shaft core 5. Also, the upper frame 11
The rear passage 19 has a smaller diameter than the elastic body 3 and a larger diameter than the pressing rod 9 when the lower frame 13 and the lower frame 13 are tightened. A step surface 21 is formed at a boundary between the cavity surface 15 and the front passage 17.

The upper channel 11 and the lower frame 13 are provided with a tubular flow path 2.
3 are formed. One end of the channel 23 is open to the outer wall of the outer frame 7. Further, the other end of the flow path 23 is
1 has an opening at the radially innermost portion.
The opening at the other end forms a front jet port 25.

The pressing rod 9 also has a tubular flow path. The flow path includes a main flow path 27 that extends in the axial direction of the pressing rod 9, a rear branch 29 that branches from the main flow path 27 and extends in an oblique direction, and a branch from the main flow path 27 that is closer to the front than the rear branch 29. Tributary 31 that extends diagonally
Consists of One end of the rear branch stream 29 is open to the side wall of the pressing rod 9. One end of the front branch 31 is opened near the front end ((chamfered portion)) of the side wall of the pressing rod 9.
The front branch 31 and the rear branch 29 are so-called drill holes, and have a smaller diameter than the main channel 27. The openings of the front branch 31 and the rear branch 29 form a rear jet port 33.

FIG. 3 is an enlarged left side view showing the pressing rod 9 of FIG. In this figure, four parts of the rear jet port 33 (spout ports formed by the front branch stream 31) are shown at four places. That is, four front tributaries 31 are formed on the pressing rod 9. As is clear from FIG. 3, the four front tributaries 31 are equidistant (90 ° in center angle).
). Although not shown, four rear tributaries 29 are formed at equal intervals, similarly to the front tributary 31. Of course, the numbers of the front branch 31 and the rear branch 29 are not limited to four. The outer diameter of the pressing rod 9 is smaller than the inner diameter of the elastic body 3.

FIG. 4 is a flowchart showing a method of manufacturing a tubular elastic product (in this example, a roller) using the extracting device 1 shown in FIGS. 1 to 3. FIG.
FIG. 5 is a schematic diagram for explaining the manufacturing method of FIG. 4.

In this production method, first, a base rubber, a crosslinking agent, and various additives are kneaded to obtain a rubber composition (S
TP1). Next, from this rubber composition, a cylindrical long body 35 as shown in FIG. 5A is formed (STP).
2). For molding the long body 35, a known molding method such as an injection molding method or an extrusion molding method can be used. Long body 35
Simultaneously with or after the molding of the rubber composition, the rubber composition is heated and crosslinked by a predetermined method.

Next, as shown in FIG. 5B, the shaft core 5 penetrates into the elongated body 35 (STP3). The outer diameter of the shaft core 5 is equal to or slightly larger than the inner diameter of the elongated body 35. The material of the shaft core 5 is not particularly limited, and a metal, a synthetic resin, or the like can be used.

Next, the surface of the long body 35 is polished using a tool such as a cylindrical grinder (STP4). By this surface polishing, removal of a skin layer generated on the outer peripheral surface of the elongated body 35 during molding, adjustment of the outer diameter of the elongated body 35, adjustment of the surface roughness of the elongated body 35, and the like are performed.

Next, the elongated body 35 is cut into a predetermined width (STP5). This cutting is achieved, for example, by rotating the shaft core 5 while pressing the cutter blade against the elongated body 35, that is, by rotating the elongated body 35. At this time, the tip of the cutter blade eventually reaches the outer peripheral surface of the shaft core 5 or slightly cuts into the inside of the shaft core 5. If the cutter blade cuts into the shaft core 5,
A shaft core 5 made of a synthetic resin or the like is used. By cutting,
A plurality of cylindrical elastic bodies 3 are obtained from the long body 35. FIG.
(C) shows a state in which the long body 35 is cut at five places and six elastic bodies 3 are obtained.

Next, as shown in FIGS. 1 and 2, the elastic body 3 is put into the outer frame 7 together with the shaft core 5 (STP).
6). Then, the outer frame 7 is tightened by pressurizing means such as a press machine (STP7). That is, the parting surface 37 of the upper frame 11 (see FIG. 2) and the parting surface 39 of the lower frame 13 abut. In the state where the outer frame body 7 is tightened, the space formed by the cavity surface 15 (columnar space)
Is equal to or slightly larger than the outer diameter of the elastic body 3. Further, the distance in the longitudinal direction of this space is equal to or slightly larger than the length in which all the elastic bodies 3 are continuous. That is, this space can accommodate the elastic body 3. When the outer frame 7 is tightened, the forward portion of the shaft core 5 is
7 and the rearward portion is located in the rear passage 19.

Next, the front jet port 25 and the rear jet port 33
Then, compressed air is blown out (STP8). Front spout 2
The ejection from 5 is achieved by connecting one end opening of the flow path 23 to, for example, a compressor (not shown). In addition, the jet from the rear jet port 33 is supplied to the main flow path 27.
Is achieved, for example, by being connected to a compressor.

Next, the front jet port 25 and the rear jet port 33
The pushing rod 9 moves forward while the ejection of the compressed air is continued (STP9). The front end of the pressing rod 9 passes through the rear passage 19 and contacts the rear end of the shaft core 5. Then, the shaft core 5 is pressed forward (to the left in FIG. 1). By the pressing, the shaft core 5 gradually moves forward. As described above, since the front passage 17 has a smaller diameter than the elastic body 3, the front end face of the elastic body 3 abuts on the step surface 21 and does not move. That is, the shaft core 5 and the elastic body 3 gradually displace. On this occasion,
The jetted compressed air enters between the outer peripheral surface of the shaft core 5 and the inner peripheral surface of the elastic body 3 to reduce the frictional force between them, so that the displacement can be performed smoothly.

As the push rod 9 continues to advance, the shaft core 5 passes through the front passage 17 and is pushed out of the outer frame 7. Since the elastic body 3 remains in the outer frame 7,
The elastic body 3 and the shaft core 5 are separated (STP10). A pressing rod 9 is loosely passed through the remaining elastic body 3.

Next, the pressing rod 9 retreats from the outer frame 7 (STP11), and the outer frame 7 is opened (STP12).
At this stage, the elastic body 3 is in contact with the cavity surface 15 of the lower frame 13.
It is lined up neatly. The elastic body 3 is automatically handled and taken out of the outer frame 7 (STP1).
3). As an example of the handling means, an arm 41 penetrating the elastic body 3 as shown in FIG. The elastic body 3 is transported to the next step by the arm 41, and is subjected to processes such as cleaning, mounting of a formal core rod, and inspection. The outer frame 7 may be opened before the pressing rod 9 retreats, and the arm 41 or the like may receive the elastic body 3 from the pressing rod 9. In this manner, a cylindrical elastic product (namely, a roller) as a final product is obtained.

In this manufacturing method, the separation between the elastic body 3 and the shaft core 5 is performed without manual operation. Further, handling of the elastic body 3 after separation can be automated. The cycle from the loading step (STP6) to the removing step (STP13) of the elastic body 3 is automatically controlled by being automated including the step of loading the elastic body 3 and the shaft core 5 into the outer frame 7 (STP6). It is also possible to control the process by a program or the like. Further, it is also possible to control the process by an automatic control program or the like, including the step of penetrating the shaft core 5 (STP3), the step of polishing the surface (STP4) and the step of cutting (STP5). This manufacturing method is excellent in work efficiency, and can reduce the manufacturing cost of the cylindrical elastic product.

When the elastic body 3 and the shaft core 5 are separated, the elastic body 3
From the viewpoint that the movement of the front passage 17 is surely prevented.
Is preferably 0.9 times or less, more preferably 0.8 times or less, and particularly preferably 0.7 times or less of the outer diameter of the elastic body 3.

The pressure of the compressed air is preferably 0.2 MPa or more. If the pressure is less than the above range, the elastic body 3 and the shaft core 5 may not be separated smoothly. In this respect, the pressure is particularly preferably equal to or greater than 0.28 MPa. Usually, the pressure is 0.5 MPa or less, particularly 0.4 MPa or less.

[0030] Instead of compressed air, another pressurized fluid may be used. Other fluids include, for example, water. Compressed air is a preferable pressurized fluid because it can be prepared with a simple device, does not deteriorate the working environment, and has no adverse effect on the cylindrical elastic product.

In the example of FIG. 1, the shaft core 5 penetrates the six elastic members 3, but the number of the elastic members 3 is not limited to this.
The shaft core 5 may penetrate into the single elastic body 3, and the shaft core 5 may be removed from the elastic body 3 by the extracting device 1 shown in FIG. 1.

[0032]

As described above, according to the manufacturing method of the present invention, a cylindrical elastic product can be manufactured automatically without causing damage or deformation. According to this manufacturing method, the manufacturing cost of the cylindrical elastic product is reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a sampling device used in a manufacturing method according to an embodiment of the present invention, together with an elastic body and a shaft core.

FIG. 2 is a left side view showing the extracting device of FIG. 1;

FIG. 3 is an enlarged left side view showing the pressing rod of FIG. 1;

FIG. 4 is a flowchart showing a method of manufacturing a tubular elastic product using the extraction device shown in FIGS. 1 to 3;

FIG. 5 is a schematic diagram for explaining the manufacturing method of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Extraction device 3 ... Elastic body 5 ... Shaft core 7 ... Outer frame body 9 ... Press rod 11 ... Upper frame 13 ... Lower frame 15 ... Cavity surface 17 ·································································································· ..Backward spout 35 ・ ・ ・ Long body 37,39 ・ ・ ・ Parting surface 41 ・ ・ ・ Arm

Claims (4)

[Claims] 1. A cylindrical elastic body and a shaft penetrating the elastic body are connected to a cavity surface forming a space capable of accommodating the elastic body, the cavity surface being located forward of the cavity surface, and being positioned in front of the elastic body. A charging step of charging into an outer frame body having a small diameter and a larger diameter than the axis, a front passage, a rear passage located behind the cavity surface, and a step surface located at a boundary between the cavity surface and the front passage. While blowing the pressurized fluid between the elastic body and the shaft core, the front end of the elastic body is fixed at the step surface, and the shaft core is pushed out of the front passage with the pressing rod inserted from the rear passage to form the elastic body. A method for producing a cylindrical elastic product, comprising: a separation step of separating an axial core. 2. The manufacturing method according to claim 1, wherein the pressurized fluid is jetted from a front jet formed near a step surface of the outer frame and a rear jet formed near a front end of the pressing rod. . 3. The method according to claim 1, further comprising a removing step of removing the elastic body from the outer frame, wherein the charging step, the separating step, and the removing step are performed by continuous automatic control. Manufacturing method. 4. The method according to claim 1, wherein one of the plurality of elastic bodies is
The manufacturing method according to any one of claims 1 to 3, wherein the cores are inserted into the outer frame in a state where the cores are inserted.