JPH031229Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vulcanization mold for forming a tubular body. More specifically, the present invention provides a vulcanized material for forming a tubular body in which a flexible sleeve for a rolling member of a fluid pressure device can be vulcanized and bonded between an inner layer unvulcanized rubber sheet and an outer layer unvulcanized rubber sheet. It concerns sulfur molds.

[Prior Art] Shock absorbers are used as shock absorbing members, vibration prevention members, load supporting members, etc. in motorcycles, automobiles, etc.

FIG. 1 is an explanatory diagram of a shock absorber, in which 1 is an inner cylinder, 2 is a guide rod, 3 is an outer cylinder, 4 is a flexible sleeve, and 5 is a cap.

The inner cylinder 1 has an open upper end and a guide rod 2 in the center.
are integrated. The outer cylinder 3 is designed such that the inner cylinder 1 can be inserted thereinto by an appropriate length. One end of the flexible sleeve 4 is bent outward, and the periphery of the end is fitted between the outer cylinder 3 and the flexible sleeve 4.
Further, the periphery of the other end is fitted and connected by a cap 5 on the outer peripheral surface of the inner cylinder 1.

In the shock absorber, a fluid-tight chamber is formed by the outer cylinder 3, inner cylinder 1, and flexible sleeve 4, and is designed to absorb external shocks applied in the longitudinal direction.

Therefore, since the flexible sleeve 4 is subjected to repeated bending, vibration, vehicle body loads, etc., there is a strong demand for the flexible sleeve 4 to exhibit excellent bending resistance even under large loads. Moreover, flexible sleeve 4
An important requirement is that the material be thin, since thick walls will impede bending resistance.

Now, the flexible sleeve 4 includes one consisting only of a rubber layer and a laminate of a rubber sheet and a rubber reinforcing fabric.

The former flexible sleeve 4 consisting only of a rubber layer has poor bending resistance under heavy loads and is not used much. On the other hand, the latter flexible sleeve 4 made of a rubber sheet and a rubber reinforcing fabric is widely used.

Here, as the rubber reinforcing fabric, an unvulcanized rubber sheet-topped blind weave is used, in which rubber reinforcing reinforcing cords are woven in a blind pattern and both sides of the cord are topped with unvulcanized rubber sheets.

The commonly used flexible sleeve 4 is made of a rubber sheet and a woven fabric. Two layers of unvulcanized rubber sheet toppings are vulcanized and bonded between an inner layer of unvulcanized rubber sheet and an outer layer of unvulcanized rubber sheet. The structure is as follows. In this case, the two layers of unvulcanized rubber sheet toppings are manufactured so that the winding directions are opposite to each other in order to improve bending resistance.

If you look at these work steps, they will look like this:

1 Preparation of materials Prepare the following materials.

Unvulcanized rubber sheet for inner layer Unvulcanized rubber sheet for outer layer Inner layer side unvulcanized rubber sheet topping blind weave Outer layer side unvulcanized rubber sheet topping weave 2 Preparation of vulcanization mold Shape of flexible sleeve 4 to be manufactured, Prepare a vulcanization mold as shown in Figure 2, which has dimensions matched to the mold.

Core metal 8 (tapered type) Medium molds 9, 10 (type with a flange to prevent misalignment when the core metal 8 and outer mold 7 are combined) Outer mold 7 (ring-shaped groove 6 is inserted into the inner mold) Hold it around the circumference,
(cylindrical type that can be divided into upper and lower halves) 3 Unvulcanized flexible sleeve 11 on core bar 8
Wrapping the unvulcanized rubber sheet for the inner layer around the core bar 8,
Next, wrap the inner unvulcanized rubber sheet topping blind weave around the upper layer, and then wrap the outer unvulcanized rubber sheet topping blind weave around the upper layer.What is the winding direction of the inner unvulcanized rubber sheet topping blind weave? The unvulcanized flexible sleeve 11 is preformed by winding in the opposite direction and finally by winding the unvulcanized rubber sheet for the outer layer.

4. Vulcanization molding of the unvulcanized flexible sleeve 11 preformed on the core metal 8 The unvulcanized flexible sleeve 11 molded on the core metal 8 is molded into the lower outer mold 7 as shown in FIG.
is fitted into a predetermined position, and then the middle molds 9 and 10 are fitted into the small diameter portions at both ends of the core bar 8. Finally, the upper outer mold 7 is covered from above, and the concave portion of the outer mold 7 and the flanges of the middle molds 9 and 10 are engaged and integrated.

Although the vulcanization mold set in this manner is not shown, it is pressurized and vulcanized for a predetermined period of time by contacting it from above and below with a hot plate at a high temperature or in a high-temperature vulcanization device.

After pressure vulcanization, each vulcanization mold is removed and the vulcanized flexible sleeve is taken out.

[Problems to be solved by the invention] However, in such conventional methods, a thin flexible sleeve made of a rubber reinforcing fabric layer is vulcanized and bonded between an inner unvulcanized rubber sheet and an outer unvulcanized rubber sheet. When doing so, it was difficult to completely prevent confusion between layers and generation of bubbles.

That is, if the gap between the vulcanization mold and the unvulcanized flexible sleeve 11 is large, foaming of the rubber sheet layer or poor adhesion with the rubber reinforcing fabric layer may occur.
As a result, the bending resistance of the resulting flexible sleeve is significantly deteriorated.

On the other hand, if the gap between the vulcanization mold and the unvulcanized flexible sleeve 11 is small, the unvulcanized rubber sheet for the inner layer and the unvulcanized rubber sheet for the outer layer that were exposed to high temperature and high pressure during vulcanization will overflow. As a result, the four layers are disordered, that is, the unvulcanized rubber sheet for the inner layer, the unvulcanized rubber sheet for the outer layer, the unvulcanized rubber sheet topping blind weave on the inner layer, and the blind weave topping the unvulcanized rubber sheet on the outer layer. As a result, the bending resistance of the resulting flexible sleeve is significantly deteriorated.

Therefore, it is necessary to strictly control the thickness of each of these four materials, but these materials do not have uniform thicknesses like metal plates, and it is extremely difficult to completely adjust them to predetermined dimensions.

Furthermore, even if these four materials are made to the specified dimensions, disturbances and foaming between the layers must be completely prevented due to the overlap of high temperature, high pressure conditions, thermal expansion, plastic flow, vulcanization, adhesion, etc. during vulcanization molding. It is difficult to do so.

The present invention has been developed based on this point, and its purpose is to eliminate the drawbacks of the prior art described above, and to solve the problem of thin wall thickness, high temperature and high pressure conditions during vulcanization molding, and thermal expansion. To provide a vulcanization mold for forming a tubular body that can completely prevent disturbance and foaming of each layer even when plastic flow, vulcanization, adhesion, etc. overlap, and as a result, a flexible sleeve with excellent bending resistance can be produced. be.

[Means for Solving the Problems] The gist of the present invention is to provide a split cylindrical outer mold in which a ring-shaped groove is formed on the inner periphery, a rod-shaped core metal, and a combination of the outer mold and the core metal. A special expandable cylindrical rubber elastic body and its expandable cylindrical rubber can be used to uniformly vulcanize the core metal in a vulcanization mold for forming a tubular body consisting of a positioning medium placed between the two. The present invention is provided with a high-pressure gas jetting device that can quickly and uniformly expand the elastic body.

That is, the core metal of the present invention has an opening in the form of a countersunk thread along the axial center of the core rod from the inlet at one end of the core to the intermediate position, and from the intermediate position on the circumferential surface of the core rod. A through hole is connected perpendicularly to the exit of the core rod in the diametrical direction of the core rod, and a countersunk threaded valve is connected to the core rod through a heat-resistant non-adhesive resin film sealing material at the outlet of the core rod through hole. A cylindrical rubber elastic body is inserted so as to be movable in the diametrical direction of the core rod, and a cylindrical rubber elastic body is disposed on the outer peripheral side of the core rod, and the axial end of the cylindrical rubber elastic body and the end in front of the core rod are The vulcanization mold for forming a tubular body is characterized in that the vulcanization mold for forming a tubular body is formed by being integrally bonded and expandable by high-pressure gas fed from the outlet of the through-hole of the core rod portion.

[Function] The vulcanization mold for forming a tubular body of the present invention allows high-pressure gas to pass through the through hole from the inlet at one end of the core rod portion of the core metal, and further through the high-pressure gas jet port on the circumferential surface of the core rod portion. There, the cylindrical rubber elasticity is quickly and uniformly compressed while receiving the synergistic buffering effect of the heat-resistant non-adhesive resin film seal member inserted into the outlet and the countersunk threaded valve inserted so as to be movable up and down. The unvulcanized air sleeve preformed on top of the cylindrical rubber elastic body is expanded quickly and uniformly so as not to cause a delay in the rate of partial vulcanization. The goal is to adhere it softly and completely to the inner surface of the mold, and then vulcanize it uniformly at high temperature in that state.

By vulcanizing with the vulcanization mold for forming a tubular body of the present invention, an air sleeve consisting of four layers of a rubber sheet and a weave, namely, an unvulcanized rubber sheet for the inner layer, an unvulcanized rubber sheet for the outer layer, The inner and outer unvulcanized rubber sheets are topped with a blind weave, and the outer unvulcanized rubber sheet is topped with a blind weave, completely suppressing the disturbance of the four layers, completely eliminating foaming within the rubber sheet, and further improving the inner and outer rubber sheets. As a result, it is possible to obtain an air sleeve that can exhibit remarkable bending resistance by strongly adhering the air sleeve to the weave and the weave.

[Example] Next, an example of the vulcanization mold for forming a tubular body of the present invention will be described with reference to the drawings.

Figure 3 shows the first vulcanization mold for forming a tubular body of the present invention.
It is a vertical cross-sectional explanatory view showing an example.

In Fig. 3, 6 is a ring-shaped groove, 7 is an outer mold,
9 and 10 are medium-sized, 12 is a core type, 13 is a core rod part, 1
4 is a cylindrical rubber elastic body, 15 and 16 are adhesive parts (adhesive parts between the end of the cylindrical rubber elastic body 14 and the core rod part 13),
17 is a through hole, 18 is a countersunk screw-shaped metal valve, and 19 is a heat-resistant, non-adhesive resin film seal member.

The core metal 12 used in the first embodiment of the vulcanization mold for forming a tubular body of the present invention is similar in shape and dimensions to the conventional core metal 8, but is different in the following points. .

First, a cylindrical rubber elastic body 14 is provided on the outer peripheral side of the ring-shaped groove 6 so as to be expandable. That is, both ends of the cylindrical rubber elastic body 14 are adhered to the ends of the core bar 12 (adhesive parts 15 and 16).
The middle part can be expanded by filling with high-pressure gas without adhesion.

The second is a through hole 17 that extends from the inlet on the one end side of the core bar 12 to an approximately central position in the axial direction and penetrates from there to the outlet on the outer circumferential surface of the core rod portion 13.
is formed. The outlet on the outer circumferential surface of the core rod portion 13 has a large opening in the shape of a countersunk screw, and high-pressure gas can be rapidly sent out from the inlet at one end of the core bar 12 through the through hole 17.

The third feature is that a special high-pressure air blowing device is provided at the outlet of the outer peripheral surface of the core rod portion 13 of the through hole 17.

FIG. 4 is an enlarged longitudinal cross-sectional view of the high-pressure gas blowing device, in which the countersunk screw-shaped metal valve 18 is connected to the outlet in the radial direction of the core rod portion 13, that is, the outer circumferential surface via the heat-resistant non-adhesive resin film seal member 19. Penetrating hole 1
It is inserted movably upwards of 7. This FIG. 4 shows the state when high pressure gas is not fed.

This countersunk screw-shaped metal valve 18 is pushed up by high-pressure gas such as high-pressure air, high-pressure nitrogen, etc. sent from the inlet of the through-hole 17 at one end of the core bar 12, and the core portion 13 of the through-hole 17 is pushed up. It can move up and down the outlet on the outer peripheral surface, and also has the function of a high-pressure gas leak prevention valve after the high-pressure gas is sent in, and its length is long enough to prevent it from leaking out.

In addition, heat-resistant non-adhesive resin film seal member 1
9 is a heat-resistant, non-adhesive resin film, for example, a film made by stacking several sheets of tetrafluoroethylene resin film and cutting it out to form a countersunk screw-shaped sealing member.

Such a heat-resistant non-adhesive resin film sealing member 19 is connected to the through hole 17 from the inlet at one end of the core bar 12.
When high-pressure gas is quickly sent out through the outlet on the outer peripheral surface of the core rod portion 13, the high-pressure air is uniformly and quickly sent into the cylindrical rubber elastic body 14 by synergistic buffering action with the countersunk screw-shaped metal valve 18. Can be inflated. By doing this, the unvulcanized air sleeve preformed on the cylindrical rubber elastic body 14 is rapidly and uniformly inflated and brought into soft and complete contact with the inner surface of the outer mold. By vulcanizing at high temperatures, uniform vulcanization can be achieved throughout.

Next, a vulcanization method according to the first embodiment of the vulcanization mold for forming a tubular body of the present invention will be described.

First, prepare the following materials as before.

Unvulcanized rubber sheet for inner layer Unvulcanized rubber sheet for outer layer Inner layer side unvulcanized rubber sheet topping blind weave Outer layer side unvulcanized rubber sheet topping weave 2 Preparation of vulcanization mold The vulcanization mold is the tubular shape of the present invention The first vulcanization mold for body formation
Prepare example products.

3 Unvulcanized flexible sleeve 1 on core metal 12
Preforming of 1 Wrap the inner layer unvulcanized rubber sheet around the core bar 12, then wrap the inner layer side unvulcanized rubber sheet topping blind weave around the core bar 12, then wrap the outer layer side unvulcanized rubber sheet topping blind weave around the upper layer. The unvulcanized flexible sleeve 11 is preformed by wrapping the weave in a direction opposite to the winding direction of the inner layer side unvulcanized rubber sheet topping blind weave, and finally wrapping the outer layer unvulcanized rubber sheet.

In this case, since the cylindrical rubber elastic body 14 is provided on the outer periphery of the core rod portion 13 of the core bar 12, the molded unvulcanized flexible sleeve 11 is attached to the core bar 13.
It is preformed on the cylindrical rubber elastic body 14 provided on the outer periphery of the core rod portion 13 of No. 2.

4. Vulcanization molding of the unvulcanized flexible sleeve 11 preformed on the core metal 12 The unvulcanized flexible sleeve 11 preformed on the core metal 12 is molded into the lower outer mold 7 as shown in FIG. Fit it into the specified position, then insert the core metal 12
The middle molds 9 and 10 are fitted into the small diameter portions at both ends of the mold. Then, the upper outer mold 7 is placed over the mold from above, and the concave portion of the outer mold 7 and the flanges of the middle molds 9 and 10 are engaged with each other to be integrated.

Next, a high-pressure hose (not shown) is connected to the entrance of the through-hole 17 at one end of the core metal 12, and high-pressure air is sent into the through-hole 17 from the high-pressure hose. The high-pressure air sent in enters between the core rod portion 13 and the cylindrical rubber elastic body 14 while pushing up the heat-resistant non-adhesive resin film seal member 19 and the countersunk threaded metal valve 18, and enters between the core rod portion 13 and the cylindrical rubber elastic body 14. Inflate 14. Since the heat-resistant non-adhesive resin film seal member 19 is a resin film seal member that has heat resistance and non-adhesive properties, it smoothly separates from the outlet on the outer peripheral surface of the core rod portion 13, further pushes up the countersunk threaded metal valve 18, and This allows high pressure air to be sent out quickly. At this time, the countersunk screw-shaped metal valve 18 and the heat-resistant non-adhesive resin film seal member 19 pushed up can effectively buffer and uniformly send out even if a large amount of high-pressure air is suddenly sent in. Due to the swelling of the cylindrical rubber elastic body 14, the unvulcanized flexible sleeve 11 formed thereon is uniformly pressed against the inner circumferential surface of the outer mold 7.

Next, although not shown, the vulcanization mold thus constructed is pressure-vulcanized for a predetermined period of time in contact with a hot platen at a high temperature from above and below or in a high-temperature vulcanizer.

After pressure vulcanization, the high-pressure air sent into the through holes 17 is removed, and then each vulcanization mold is removed and the vulcanized flexible sleeve is taken out.

In the vulcanization method according to the first embodiment of the vulcanization mold for forming a tubular body of the present invention, the unvulcanized rubber sheet for the inner layer and the topping of the inner layer side unvulcanized rubber sheet occur when the material is thick. A first embodiment of the vulcanization mold for forming a tubular body of the present invention, in which there is no disturbance at all between each layer of the blind weave, the unvulcanized rubber sheet topping for the outer layer, and the unvulcanized rubber sheet for the outer layer. In the vulcanization method, the pressure is applied by the swelling of the cylindrical rubber elastic body 14, so the pressure is uniform, and as a result, the unvulcanized rubber sheet for the inner layer and the unvulcanized rubber sheet for the outer layer, which occur when the thickness of the material is thin, are applied. It is possible to completely prevent the occurrence of defects such as foaming of the rubber sheet and occurrence of missing parts in the rubber layer.

Figure 5 shows the second vulcanization mold for forming a tubular body of the present invention.
FIG. 2 is an explanatory longitudinal cross-sectional view of a core metal 12 used in an example.

The feature of the second embodiment of the vulcanization mold for forming a tubular body according to the present invention is that, as shown in FIG. The ring-shaped convex portions provided at both ends of the cylindrical rubber elastic body 14 fit into and adhere to the ring-shaped grooves 22 and 23.

In the second embodiment of the vulcanization mold for forming a tubular body of the present invention, the ring-shaped grooves 22 and 23 of the core rod part 13 and the inner ring-shaped convex part of the cylindrical rubber elastic body 14 fit together, Since it is bonded, the adhesive force is strong and the repeated use life of the cylindrical rubber elastic body 14 can be extended. That is, it is possible to effectively reduce peeling defects of the cylindrical rubber elastic body 14 due to repeated use.

Figure 6 shows the third vulcanization mold for forming a tubular body of the present invention.
FIG. 2 is an explanatory longitudinal cross-sectional view of one end of the main part of the core rod portion 13 of the core mold 12 used in the example.

The features of the third embodiment of the vulcanization mold for forming a tubular body of the present invention are as shown in FIG. Cylindrical rubber elastic body 14 around the adhesive part 20 with the side end part
The wall thickness x1 at the end is thicker than the wall thickness x2 at the center (non-bonded part).

In this case, the cylindrical rubber elastic body 1 around the adhesive part 20
The wall thickness of the four ends x1 = 10 mm, and the center part (non-bonded part) wall thickness x2 = 5 mm.

Although not shown, the bonded portion between the other end of the core rod portion 13 of the core bar 12 and the other end of the cylindrical rubber elastic body 14 is configured similarly.

According to the third embodiment of the vulcanization mold for forming a tubular body of the present invention, the adhesive portion 2 at the end of the cylindrical rubber elastic body 14
Since the wall thickness around 0 is thick, even if the cylindrical rubber elastic body 14 is expanded by the high-pressure air sent from the through hole 17, the expansion around the end bonding part 20 is small.
As a result, the unvulcanized rubber sheet for the inner layer around both ends of the unvulcanized flexible sleeve 11 molded on the core bar 12, the unvulcanized rubber sheet topping blind weave on the inner layer side, and the unvulcanized rubber sheet topping blind weave on the outer layer side. Disturbance between the layers of the weave and the unvulcanized rubber sheet for the outer layer can be effectively suppressed.

Figure 7 shows the fourth vulcanization mold for forming a tubular body of the present invention.
FIG. 2 is an explanatory longitudinal cross-sectional view of a main part of one end of a core metal 12 used in an example.

The characteristics of the fourth embodiment of the vulcanization mold for forming a tubular body of the present invention are as shown in FIG. The position of the adhesive portion 21 with the side end portion is specified. That is, when the respective molds are combined, the adhesive portion 21 is positioned outside the ring-shaped groove 6 of the outer mold 7 and in contact with the inner peripheral surface other than the ring-shaped groove 6. be.

Although not shown, the bonded portion between the other end of the core rod portion 13 of the core bar 12 and the other end of the cylindrical rubber elastic body 14 is configured similarly.

According to the fourth embodiment of the vulcanization mold for forming a tubular body of the present invention, even if the cylindrical rubber elastic body 14 is swollen by the high pressure air sent through the through hole 17, the adhesive portion 21 remains inside the end of the outer mold 7. Since it is held down by the circumferential surface, deformation of the core bar 12 is reduced and its service life can be extended, and deformation around both ends of the unvulcanized flexible sleeve 11 molded on the core mold 12 is effectively suppressed. be able to.

Although the tapered flexible sleeves have been described in these embodiments, it is of course possible to vulcanize linear flexible sleeves.

[Effects of the invention] The vulcanization mold for forming a tubular body of the invention has a thin wall thickness and is resistant to high temperature and high pressure conditions, thermal expansion, plastic flow, vulcanization, adhesion, etc. during vulcanization molding. It is possible to completely prevent disturbance and foaming of each layer, and as a result, a flexible sleeve can be obtained that exhibits excellent bending resistance, and is industrially useful.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a commonly used shock absorber, Fig. 2 is an explanatory longitudinal cross-sectional view of a conventional vulcanization mold for forming a tubular body, and Fig. 3 is a vulcanization mold for forming a tubular body according to the present invention. A vertical cross-sectional explanatory diagram showing a first embodiment of
FIG. 4 is an enlarged vertical cross-sectional explanatory view of a high-pressure gas blowing device provided at the outlet on the outer peripheral surface of the core rod of the first embodiment of the vulcanization mold for forming a tubular body of the present invention, and FIG. A vertical cross-sectional explanatory view of a core metal used in the second embodiment of the vulcanization mold for forming a body, and FIG. 6 shows a core of the core metal used in the third embodiment of the vulcanization mold for forming a tubular body of the present invention. FIG. 7 is an explanatory longitudinal cross-sectional view of an essential part of one end of a rod portion, and FIG. 1: Inner cylinder, 2: Guide rod, 3: Outer cylinder, 4: Flexible sleeve, 5: Cap, 6: Ring-shaped groove, 7: Outer mold, 8, 12: Core metal, 9, 10: Medium size, 13 : Core rod part, 14: Cylindrical rubber elastic body, 1
5, 16, 20, 21: Adhesive part, 17: Through hole,
18: Flat head screw-shaped metal valve, 19: Heat-resistant non-adhesive resin film seal member, 22, 23: Ring-shaped groove.

Claims (1)

[Claims for Utility Model Registration] 1. A split cylindrical outer mold that forms a wide ring-shaped groove on the inner periphery in which a tubular body can be placed when combined, and a rod-shaped outer mold that is set within the outer mold. A vulcanization mold for forming a tubular body comprising a core bar and a positioning medium die disposed between the outer die and the core bar at both ends, wherein the core bar is located at one end side of the core bar part. from the inlet to the intermediate position along the axial center of the core rod, and from the intermediate position to the outlet opened in the shape of a countersunk screw on the circumferential surface of the core rod perpendicularly to the diameter direction of the core rod. The holes are connected to each other, and a countersunk threaded valve is inserted into the outlet of the core rod portion through hole through a heat-resistant non-adhesive resin film seal member so as to be movable in the diametrical direction of the core rod portion, Moreover, a cylindrical rubber elastic body is provided on the outer circumferential side of the core rod portion, and the axial end of the cylindrical rubber elastic body and the front end of the core rod portion are adhesively integrated and fed from the outlet of the through hole of the core rod portion. 1. A vulcanization mold for forming a tubular body, characterized in that the mold is configured to be expandable by high-pressure gas. 2. Forming a ring-shaped groove at the end of the core bar of the core metal,
The vulcanization for forming a tubular body according to claim 1 of the utility model registration claim, characterized in that a ring-shaped convex portion provided at the end of the tubular rubber elastic body is fitted into the ring-shaped groove and adhered thereto. Mold. 3. The adhesive part between the end of the core bar of the core bar and the end of the cylindrical rubber elastic body should be in a position where it contacts the inner circumferential surface of the outer mold other than the ring-shaped groove when the molds are combined. A vulcanization mold for forming a tubular body according to claim 1, which is characterized in that it is constructed as follows.