JPH0213412Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a shaft for winding or unwinding webs, and is a shaft for winding or unwinding webs such as paper, cloth, metal sheets, etc. It is used as a.

(Prior Art) Conventionally, a shaft for winding or unwinding a web has cones 2, 2 on both sides of a central shaft 1, as shown in FIG.
It is common that the cones 2, 2 are installed to face each other, and by sliding the cones 2, 2, a paper tube 4 for winding paper 3 is fixedly held concentrically with the central axis 1. It was hot. However, this structure has poor work efficiency because it is necessary to remove the cone 2 when attaching or detaching the paper tube 4 to the central shaft 1. Shafts are now being used.

This air shaft has a structure in which lugs 6, 6 are provided on the outer wall of a hollow shaft 5 so as to be protrusive and retractable, and a rubber tube 7 is installed for protruding and retracting the lug 6 into the hollow shaft 5. The paper tube 4 can be fixed and held concentrically with the hollow shaft 5 by introducing air and causing the lugs 6, 6 to protrude and come into contact with the inner wall of the paper tube 4. Note that the lugs 6, 6 are arranged on the circumference of the hollow shaft 5, for example, at 4
On the other hand, in the longitudinal direction of the hollow shaft 5, for example, four pieces per meter are provided at equal intervals.

(Problems to be solved by the invention) The air shaft has improved workability when attaching or detaching paper tubes, and has come to be used in many fields, but it has the following problems. Ta.

(1) When the total weight of the web such as paper or metal sheet wound around the paper tube is heavy, the pressing force of the lugs cannot counteract this weight, and as a result, the hollow shaft 5 and the paper tube 4
The distance between the two is eccentric as shown in Fig. 3. Due to this eccentricity, the tension on the web becomes non-uniform, and there is a problem in that the web is wound unevenly during the winding operation.

The force of the lug pushing up the paper tube is roughly estimated as follows. First of all, one lug has a pressure receiving area of 16cm ² (width 2cm, length 8cm) from the rubber tube.
cm) and the compressed air injected into the rubber tube is 4Kg/ ^cm2 , then the product of both, 64Kg, becomes the pushing force. And, per 1 m of the hollow shaft 5,
If there are 4 rugs in a row, per meter
A pushing force of 256Kg (64Kg x 4) will be obtained.

If the web is made of paper and is rolled up to a diameter of 1 m, its weight will be approximately 500 kg (per 1 m), which means that the pushing up force of the lugs cannot counteract it. When the web is made of cloth or metal sheet, the problem of eccentricity also occurs due to the additional weight.

(2) When the hollow shaft is rotated in the eccentric state described above, the lugs that retract due to the load move sequentially to adjacent lugs on the circumference, so each lug repeatedly protrudes and retracts. As a result, the contact surface between the lug and the rubber tube and its surroundings were damaged due to fatigue due to repeated friction and deformation, resulting in a problem of air leakage.

(3) Also, since the pressure of the lug in contact with the paper tube is as large as 64Kg, as shown in the estimate of the push-up force above,
It was also necessary to increase the wall thickness of the paper tube to provide high strength. Normally, this paper tube is not used repeatedly.
This was wasteful in terms of cost since it was discarded after one use.

(Means for Solving Problems) The web winding or unwinding shaft of this invention has a plurality of hollow expansion rings made of tire-like elastic bodies fitted on the outside of a hollow shaft with spacer rings sandwiched between them. an inner ring is installed between the inner peripheral edges of the hollow expansion rings, and the inside of each hollow expansion ring and the inside of the hollow shaft are connected to each other through holes bored in the side wall of the hollow shaft and the inner ring. The hollow expansion ring, the spacer ring and the inner ring are tightened in the longitudinal direction of the hollow shaft, so that the inner peripheral edge of the hollow expansion ring is connected to the spacer ring and the inner ring, and the inner ring is in communication with the spacer ring and the inner ring. It is characterized by being pressed and fixed to the surface.

The structure for press-fixing the inner peripheral edge of the hollow expansion ring to the outer peripheral surface of the hollow shaft is such that the side surface of the inner peripheral edge is brought into contact with the spacer ring and the inner ring at their respective tapered surfaces, and the hollow expansion ring body is pressed and fixed to the outer peripheral surface of the hollow shaft. Preferably, the structure is such that when the annular body, spacer ring, and inner ring are tightened in the longitudinal direction of the hollow shaft, a force component directed toward the hollow shaft is applied to the inner circumferential edge.

(Function) In the shaft for winding or unwinding a web having the above structure, since a large number of hollow expansion rings are arranged in the axial direction, the pushing force per unit length can be increased. As a result, it becomes possible to sufficiently counter the weight of the wound web, and the problem of eccentricity can be solved. Since there is no eccentricity, there is no repeated expansion and contraction of the hollow expansion ring during rotation of the shaft, and damage to the expansion member due to fatigue or friction and air leakage can be avoided.

Further, since the paper tube has a structure in which the hollow expansion ring is brought into contact with and supported over almost the entire inner circumference, the pressure per unit area that the paper tube receives can be reduced. As a result, the wall thickness of the paper tube can be made thinner,
Cost problems can also be solved.

(Example) An example of this invention will be described below with reference to FIGS. 4 to 6. Reference numeral 10 in the figure is a hollow shaft, and journal shafts 12a, 1 are attached to both ends of the cylinder 11 in the intermediate portion.
2b is fitted and fixed. Thread parts 13a and 13b are provided at both ends of the cylinder 11, respectively, and an end ring 14a is fitted to one end of the cylinder 11, and the end ring 14a is slid toward the journal shaft 12a. The movement is prevented by the holding ring 15a and the nut 16a, and the hollow expansion ring 17 and the spacer ring 1 are
8 alternately, fit the end ring 14b in the vicinity of the journal shaft 12b on the other side, then fit the retainer ring 15b and nut 16b, and tighten the nut 16b (and nut 16a). As a result, a thrust load in the axial direction of the hollow shaft 10 is applied to the hollow expansion ring 17 and the spacer ring 18.

The hollow expansion ring body 17 is a tire-like elastic body made of rubber, and a metal inner ring 19 is interposed between the inner circumferential edges 17a and 17b. It is clamped by the ring 19 and the spacer ring 18, and is pressed against the circumferential surface of the cylindrical body 11 forming the hollow shaft 10 by the thrust load. That is, the inner peripheral edge 17a, 1
7b are respectively tapered surfaces 2 as shown in FIG.
0 and 20 are formed, and tapered surfaces 21 and 22 are also formed on the inner peripheral edges of the inner ring 19 and the spacer ring 18, and the tapered surfaces are brought into contact with each other so that the thrust load is applied. The inner peripheral edges 17a and 17b of the hollow expansion ring body 17 are connected to the cylinder body 11.
The hollow expansion ring 17 and the hollow shaft 10 are pressed together to keep the hollow part airtight, and the hollow expansion ring 17 and the hollow shaft 10 are integrated to prevent slippage between them.

The hollow portion of the hollow expansion ring body 17 and the hollow portion of the hollow shaft 10 are connected to each other through a hole 23 formed in the cylinder body 11 corresponding to the hollow expansion ring body 17 and a hole 24 formed in the inner ring 19. It's communicating. The journal shaft 12b is configured to be hollow, and the hollow shaft 12b is inserted through a plug 25 with a check valve provided at the end.
Compressed air can be forced into and discharged from the hollow expansion ring 17.

As shown in FIG. 6, the hollow expansion ring 17 has a circumferential surface having thick parts 26 and thin parts 27 arranged alternately, and expands in the diametrical direction when the compressed air is injected. In addition, during expansion, the peripheral surface of the thick portion 26 comes into contact with the inner peripheral surface of the paper cylinder around which the web is wound.

In the above embodiment, before the compressed air is injected, the hollow expansion ring 17 is in a contracted state, and its outer diameter is approximately equal to the outer diameter of the spacer ring 18 as shown in FIG. Therefore, the paper tube 28 on which a web of paper, cloth, metal sheet, etc. is wound or wound can be easily fitted in the same way as in a conventional air shaft.

After fitting the paper tube 28, when compressed air (4Kg/cm ² ) is pressurized into the hollow shaft 10, the hollow expansion ring 17
expands in the radial direction as shown in FIG. Can be done.

In this case, the pushing up force by the hollow expansion ring 17 can be roughly calculated as follows. That is, in the example, the width of the hollow expansion ring 17 is 3 cm, and the thick part 2
It is assumed that the circumferential length of the hollow shaft 10 is 3 cm, and 25 hollow expansion rings 17 are installed per 1 m of the hollow shaft 10. Then, the pressing force of one thick part 26 is
The weight is 36Kg (3cm x 3cm x 4Kg/cm ² ), which is 900Kg (36Kg/25) per meter.

That is, the weight of the wound web can be sufficiently resisted, and the hollow expansion ring 17 can be prevented from being deformed by the weight of the web, thereby preventing rotation in an eccentric state. Since the contact pressure between each thick wall portion 26 and the paper tube 28 is as small as 36 kg, the wall thickness of the paper tube 28 can also be made thinner.

When a rotational driving force is applied to the hollow shaft 10, the inner peripheral edges of the hollow expansion ring bodies 17, 17 fitted on the hollow shaft 10 are fixed to the outer peripheral surface of the hollow shaft 10, so that slipping occurs at these parts. There is no risk of this happening, and the entire driving force can be transmitted to the paper tube 28 side.

Incidentally, in the above embodiment, the press-in or discharge port for compressed air was provided at the end of the journal shaft 12b.
It does not necessarily have to be provided at the end, but may be provided on the journal shafts 12a, 12b or the side wall of the cylinder 11.

(Effects of the invention) As explained above, according to this invention, it is possible to increase the area of the abutment support surface for the paper tube on which the web is wound, so the pushing force against the web is also increased, and the eccentricity This has the effect of providing a shaft for winding or unwinding the web without any fear. In addition, the hollow expansion ring, which is expanded by pressurizing compressed air, deforms only slightly when it rotates while supporting the winding web, which has the effect of avoiding breakage due to friction and fatigue. . Furthermore, since the supporting pressure per unit area of the paper tube for winding the web can be reduced, there is also the effect that the wall thickness of the paper tube can be reduced.

In addition, since the inner circumferential edge of the hollow expanding ring body is pressed and fixed to the outer circumferential surface of the hollow shaft, slipping of the hollow expanding ring body is prevented, and the rotational force of the hollow shaft can be reliably transmitted to the paper tube side. There is.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional winding or unwinding shaft;
Figure 2 is also a cross-sectional view of a conventional air shaft.
Fig. 3 is a sectional view of the air shaft in use, Fig. 4 is a front view showing a section of an embodiment of this invention, Fig. 5 is a partially enlarged sectional view of the embodiment, and Fig. 6. 1 is a side view showing a part of the hollow expansible ring according to the embodiment in cross section, and FIGS. 7 and 8 are diagrams illustrating the usage state of the embodiment. 10...Hollow shaft, 17...Hollow expansion ring, 18
... Spacer ring, 23, 24 ... Hole, 28
...Paper tube.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of hollow inflatable ring bodies made of tire-like elastic bodies are fitted on the outside of the hollow shaft with spacer rings sandwiched between them, and the inner peripheral edge of the hollow inflatable ring bodies An internal ring is installed between them, and the inside of each hollow expansion ring and the inside of the hollow shaft communicate with each other through a hole bored in the side wall of the hollow shaft and the internal ring, and the hollow expansion ring, A web characterized in that the spacer ring and the inner ring are tightened in the longitudinal direction of the hollow shaft, and the inner circumferential edge of the hollow expansion ring is press-fixed to the outer circumferential surface of the hollow shaft by the spacer ring and the inner ring. Shaft for winding or unwinding. 2. The shaft for winding or unwinding a web according to claim 1, wherein the side surface of the inner circumferential edge of the hollow expansion ring body, the spacer ring, and the inner ring are in contact with each other at tapered surfaces.