JP2007083648A - Mold for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding which not only can position an inside pipe with a high accuracy but also can smoothly feed and discharge the inside pipe. <P>SOLUTION: The mold for molding for filling a gap between the inside pipe 110 and an outside pipe 120 arranged coaxially with a rubber and crosslinking the rubber, comprises a lower mold 200 provided with a dividing sleeve 210 for externally fitting the inside pipe 110 and positioning it, and an upper mold 300 provided with a spreading-out core 310 for entering into the dividing sleeve 210 and spreading out the dividing sleeve 210 in the radial direction. When the upper mold 300 and the lower mold 200 are closed, the inner peripheral face of the inside pipe 110 is strongly restricted by the outer peripheral face of the dividing sleeve 210. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold for filling a rubber into a gap between an inner pipe and an outer pipe arranged coaxially and crosslinking the rubber.

  In an automobile, a shock absorber called a steering bush is interposed on a steering shaft that connects a steering wheel and a steering gear. FIG. 7 is a perspective view showing a general shock absorber 100 used in the steering bush. FIG. 8 is a perspective view showing a state in which the shock absorber 100 of FIG. 7 is cut along a plane including its central axis. The shock absorber 100 is configured such that a rubber 130 is filled in a gap between the inner pipe 110 and the outer pipe 120 arranged coaxially, and the rubber 130 absorbs vibration. As a result, it is possible to suppress the vibration transmitted from the steering rod to the steering, and to keep the riding comfort of the automobile good. Various types of shock absorbers have been proposed so far, including those described in Patent Document 1 and Patent Document 2.

  FIG. 9 shows a state in which a general mold used for filling the rubber 130 in the gap between the inner pipe 110 and the outer pipe 120 of the shock absorber 100 to be crosslinked is cut along a plane including the central axis thereof. FIG. FIG. 10 is an enlarged cross-sectional view of the peripheral portion A of the positioning core 210 in the mold shown in FIG. This mold includes a lower mold 200 provided with a positioning core 210 for externally fitting and positioning the inner pipe 110, and a rubber supply port for filling a rubber 130 in a gap between the inner pipe 110 and the outer pipe 120. The upper mold 300 provided with the H.321 is provided. Various types of molds such as those described in Patent Document 3 and Patent Document 4 have been proposed so far.

Japanese Patent Laid-Open No. 08-170647 (Claims, FIG. 1) Japanese Patent Laying-Open No. 2002-340009 (Claims, FIG. 1) Japanese Utility Model Laid-Open No. 05-065506 (Utility Model Registration Request, FIGS. 1 and 3) Japanese Utility Model Laid-Open No. 05-025048 (Utility Model Registration Request, FIG. 1 and FIG. 3)

  However, the mold shown in FIGS. 9 and 10 can position the inner pipe 110 with high accuracy unless the gap between the inner peripheral surface of the inner pipe 110 and the outer peripheral surface of the positioning core 210 is set narrow. It was something that could not be done. However, if the gap between the inner peripheral surface of the inner pipe 110 and the outer peripheral surface of the positioning core 210 is set to be narrow, the inner pipe 110 is easily caught by the positioning core 210, so that the inner pipe 110 is smoothly supplied and discharged. There was a risk of problems such as being unable to perform.

  On the other hand, if the gap between the inner peripheral surface of the inner pipe 110 and the outer peripheral surface of the positioning core 210 is set wide, not only the positioning accuracy of the inner pipe 110 is lowered, but also the force with which the positioning core 210 holds the inner pipe 110. Becomes extremely weak, and when the upper mold 300 is moved upward after the crosslinking of the rubber 130, the shock absorber 100 moves together with the upper mold 300, and the mold cannot perform a predetermined operation. There was a risk of problems such as. This is because when the rubber 130 is completely cross-linked, the shock absorber 100 and the upper mold 300 may be connected by the rubber 130 around the rubber supply port 321 (B portion in FIG. 10).

  The present invention has been made to solve the above-described problems, and provides a mold that can not only position an inner pipe with high accuracy but also smoothly supply and discharge the inner pipe. It is also an object of the present invention to provide a mold that can hold the product firmly on the lower mold side when the upper mold and the lower mold are opened, and can reliably pull the product away from the upper mold.

  The above-mentioned problem is a mold for filling a gap between an inner pipe and an outer pipe arranged coaxially with rubber to crosslink, and provided with a split sleeve for externally fitting and positioning the inner pipe A lower die and an upper die provided with a spreading core for entering the inside of the split sleeve and pushing the split sleeve in the radial direction. When the upper die and the lower die are closed, the inner pipe This can be solved by providing a mold characterized in that the inner peripheral surface is strongly restrained by the outer peripheral surface of the split sleeve. A rubber supply port for filling the gap between the inner pipe and the outer pipe with rubber is usually provided in the upper mold.

  Here, the terms “upper” and “lower” are used only to indicate the relative positional relationship of each component of the mold, and do not necessarily indicate the absolute position of each component of the mold. is not. That is, even if the upper mold and the lower mold are arranged at the same height, or even if the upper mold is arranged at a position lower than the lower mold, as long as the gist of the present invention is not impaired, It is intended to be included in the technical scope of the invention. The same applies to the following unless otherwise specified.

  The split sleeve is not particularly limited as long as it has a plurality of split pieces that are spread by a spreading core, but has a plurality of split pieces that are fixed at the lower end and freed at the upper end. Is preferably arranged annularly around the central axis of the split sleeve. Thereby, a division | segmentation sleeve can be made into a simple structure. The divided sleeve only needs to have at least the upper end thereof divided, and may be one in which a plurality of divided pieces are integrally formed. At this time, it is also preferable to provide a thin part or a narrow part near the lower end of the divided piece. As a result, the vicinity of the lower end of the split piece can be easily elastically deformed, and the split sleeve can be easily spread.

As described above, according to the present invention, it is possible to provide a molding die that can not only position the inner pipe with high accuracy but also smoothly supply and discharge the inner pipe.
It is also possible to provide a molding die that can hold the product firmly on the lower die side when the upper die and the lower die are opened and can reliably pull the product away from the upper die.

  A preferred embodiment of the mold of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which the molding die of the present invention is cut along a plane including the central axis when the upper die 300 and the lower die 200 are open. FIG. 2 is an enlarged cross-sectional view of the peripheral portion A of the split sleeve 210 in the mold shown in FIG. FIG. 3 is a cross-sectional view showing a state where the molding die of the present invention is cut along a plane including the central axis when the upper die 300 and the lower die 200 are closed. 4 is an enlarged cross-sectional view of the periphery A of the split sleeve 210 in the mold shown in FIG. FIG. 5 is a perspective view showing the split sleeve 210 in the mold shown in FIGS. FIG. 6 is a perspective view showing a state where the split sleeve 210 in the mold shown in FIGS. 1 to 4 is cut along a plane including the central axis.

[Overview]
As shown in FIGS. 1 to 4, the molding die of the present invention is for filling a gap between the inner pipe 110 and the outer pipe 120 arranged coaxially with a rubber 130 to crosslink the inner pipe 110. A lower mold 200 provided with a split sleeve 210 for externally fitting and positioning the pipe 110, and a spread core 310 for entering the inside of the split sleeve 210 and pushing the split sleeve 210 in the radial direction are provided. The upper mold 300 is provided. In this mold, when the upper mold 300 and the lower mold 200 are closed, the inner peripheral surface of the inner pipe 110 can be strongly restrained by the outer peripheral surface of the split sleeve 210.

[Split sleeve]
As shown in FIGS. 5 and 6, the split sleeve 210 of this embodiment has a plurality of split pieces 211 arranged in an annular shape around the central axis of the split sleeve 210. The lower end of the divided piece 211 is a fixed end fixed to the upper surface of the base 212, and the upper end of the divided piece 211 is a free end that can swing around the vicinity of the lower end of the divided piece 211. The inside of the split sleeve 210 is hollow so that the spread core 310 of the upper mold 300 can enter from above.

  The split sleeve 210 may be one in which the split piece 211 and the base 212 are separately formed, but it is preferable that the split piece 211 and the base 212 are integrally formed. Thereby, the division | segmentation sleeve 210 can be made excellent in intensity | strength. In the split sleeve 210 of this embodiment, the split piece 211 and the base 212 are cut out from the same metal material, and the split piece 211 and the base 212 are integrally formed. ing. The split sleeve 210 is configured such that when the spread core 310 enters the inside thereof, the vicinity of the lower end of the split piece 211 is elastically deformed and the upper end of the split piece 211 is opened outward.

  The number of divided pieces 211 is not particularly limited as long as it is two or more, but is preferably three or more. Thereby, it becomes possible to make the split sleeve 210 into a form that is more easily spread. As shown in FIG. 5, the split sleeve 210 of this embodiment has four split pieces 211 arranged in a rotationally symmetrical manner around the central axis.

  The shape of the divided piece 211 is not particularly limited as long as the shape can support the inner peripheral surface of the inner pipe 110, and may be a rod shape or the like, but the outer surface (the surface facing the outer side) of the divided piece 211 is the inner pipe 110. It is preferable that it is formed in a shape that follows the inner peripheral surface. Thereby, when the upper mold | type 300 and the lower mold | type 200 close, it becomes possible to ensure wide contact area with the outer surface of the division | segmentation piece 211 and the inner peripheral surface of the inner side pipe 110. FIG. As shown in FIGS. 5 and 6, the split piece 211 of the present embodiment has a cylindrical outer surface, and can be in close contact with the cylindrical inner peripheral surface of the inner pipe 110. It has become.

As shown in FIG. 2, the outer surface of the split piece 211 (the outer peripheral surface of the split sleeve 210) is formed to be inclined, and the outer diameter of the split sleeve 210 becomes smaller as it approaches the upper end of the split piece 211. ing. The outer diameter of the split sleeve 210 at the lower end of the split piece 211 is set to substantially match the inner diameter of the inner pipe 110. The inclination angle θ ₁ (FIG. 2) of the outer surface of the split piece 211 is changed from the inclination angle θ ₃ (FIG. 1) of the outer peripheral surface of the spread core 310 to the inclination angle θ ₂ (FIG. 2) of the inner peripheral surface of the split sleeve 210. It is set so as to substantially match the subtracted value (θ ₃ −θ ₂ ). Therefore, when the upper mold 300 and the lower mold 200 are closed (hereinafter, sometimes referred to as “clamping”), the outer peripheral surface of the split sleeve 210 is brought into close contact with the inner peripheral surface of the inner pipe 110. Be able to.

The specific value of the inclination angle θ ₁ is not particularly limited, but if it is set too small, the gap between the inner pipe 110 and the split sleeve 210 at the time of mold opening becomes narrow, and the inner pipe 110 is externally fitted to the split sleeve 210. May be difficult to do. For this reason, the inclination angle θ ₁ is normally set to 0.1 ° or more. The inclination angle θ ₁ is preferably 0.5 ° or more, and more preferably 0.8 ° or more. On the other hand, when the inclination angle theta ₁ to set too large, no longer must greatly displace the split pieces 211 from opening of the mold toward during clamping, there is a risk that anxiety occurs in the intensity of the split sleeve 210. Therefore, the inclination angle theta ₁ is usually set to 5 ° or less. The inclination angle θ ₁ is preferably 3 ° or less, and more preferably 2 ° or less. In the mold according to this embodiment, the inclination angle θ ₁ is set to about 1 °.

As shown in FIG. 2, the inner surface of the split piece 211 (inner peripheral surface of the split sleeve 210) is formed to be inclined, and the inner diameter of the split sleeve 210 increases as it approaches the upper end of the split piece 211. ing. The inclination angle θ ₂ (FIG. 2) of the inner surface of the split piece 211 is set slightly smaller than the inclination angle θ ₃ (FIG. 1) of the outer peripheral surface of the spreading core 310. For this reason, the divided piece 211 can be swung reasonably around the vicinity of the lower end thereof.

The specific value of the inclination angle θ ₂ is not particularly limited, but if it is set too small, there is a possibility that sufficient displacement of the upper end of the divided piece 211 cannot be secured. For this reason, the inclination angle θ ₂ is normally set to 1 ° or more. The inclination angle theta ₂ is preferable to be 2 ° or more, and more preferably 3 ° or more. On the other hand, an excessively larger the inclination angle theta _2, the upper end displacement becomes too large for the divided pieces 211, split sleeve 210 may be damaged. For this reason, the inclination angle θ ₂ is normally set to 10 ° or less. The inclination angle θ ₂ is preferably 7 ° or less, and more preferably 5 ° or less. In the mold according to this embodiment, the inclination angle θ ₂ is set to about 4 °.

  In the vicinity of the lower end of the split piece 211, as shown in FIG. 2, there are provided through portions 213 along the circumferential direction of the split sleeve 210, and a thin portion having a thickness T (FIG. 2) thinner than the other portions. 214 is provided. For this reason, the cross-sectional area is small in the vicinity of the lower end of the split piece 211 and is more easily elastically deformed than other portions. The location where the punched-through portion 213 is provided may be the outer peripheral surface of the split sleeve 210, but is preferably the inner peripheral surface of the split sleeve 210. Thereby, it is possible to secure a wide inner peripheral surface of the inner pipe 110 and an outer peripheral surface of the split sleeve 210. The shape of the punched-through portion 213 is not particularly limited, but if the shape has corner portions, stress may concentrate on the corner portions and cracks may easily occur. It is preferable to penetrate the shape. In the split sleeve 210 of this embodiment, the cross-sectional shape of the punched-through portion 213 is substantially semicircular.

  Further, as shown in FIG. 5, in the vicinity of the lower end of the divided piece 211, there is provided a penetrating portion 215 along the radial direction of the divided sleeve 210, and a narrow portion 216 having a narrower width W than the other portions. Is provided. Thus, by providing the punching-through portion 215, the cross-sectional area near the lower end of the divided piece 211 can be further reduced, and the vicinity of the lower end of the divided piece 211 can be further easily elastically deformed. The location where the punched-through portion 215 is provided is not particularly limited, but in the divided sleeve 210 of the present embodiment, it is provided at the lower end of the slit 217 formed between the adjacent divided pieces 211. The shape of the punched-through portion 215 is not particularly limited. However, as with the punched-through portion 213, if the shape has a corner portion, stress may concentrate on the corner portion and cracks may easily occur. It is preferable to penetrate into a smooth shape having no part. In the split sleeve 210 of this embodiment, the punched-through portion 215 has a substantially cylindrical shape.

[Spread core]
The spreading core 310 is not particularly limited as long as it has a shape capable of entering the inside of the dividing sleeve 210 and pushing and spreading the dividing sleeve 210. As shown in FIG. 1, the spreading core 310 of this embodiment has a conical outer peripheral surface whose diameter decreases from the upper end to the lower end, and the inner periphery of the split sleeve 210 on the outer peripheral surface. The split sleeve 210 is expanded by pressing the surface. The inclination angle theta ₃ of the outer peripheral surface of the press and spread the core 310 is not particularly limited, in the mold of the present embodiment is set to approximately 5 °.

[Mold operation]
Next, the operation of the mold according to the present invention will be described in more detail. First, as shown in FIGS. 1 and 2, the inner pipe 110 is fitted on the split sleeve 210, and the outer pipe 120 is installed on the lower mold 200. At this time, the outer diameter of the upper end of the split sleeve 210 is smaller than the inner diameter of the inner pipe 110 so that the inner pipe 110 can be easily fitted onto the split sleeve 210. The supply of the inner pipe 110 and the outer pipe 120 may be performed manually, but in the molding die of this embodiment, the supply is automatically performed by a supply means (not shown).

  Subsequently, as shown in FIGS. 3 and 4, the upper die 300 is lowered to the bottom dead center, and the pushing spread core 310 is made to enter the inside of the split sleeve 210. The split sleeve 210 is gradually expanded in the radial direction as the upper die 300 descends, and when the upper die 300 reaches the bottom dead center, the outer peripheral surface thereof is in close contact with the inner peripheral surface of the inner pipe 110. It has become. The inner pipe 110 is strongly constrained on the inner peripheral surface thereof by the outer peripheral surface of the split sleeve 210, and is positioned (centered) with high accuracy. Precise positioning of the outer pipe 120 is performed by a middle mold (not shown).

  When the upper mold 300 reaches the bottom dead center, the rubber 130 is filled in the gap between the inner pipe 110 and the outer pipe 120 as shown in FIGS. In the mold of this embodiment, the rubber 130 is supplied from a rubber supply port 321 provided in the upper mold 300. When the filling of the rubber 130 is completed, the product 100 is heated by a heating means (not shown), and the rubber 130 filled in the gap between the inner pipe 110 and the outer pipe 120 is cross-linked.

  When the rubber 130 has been cross-linked, the upper mold 300 is raised. At this time, until the upper mold 300 rises about 2 to 3 mm from the bottom dead center and the rubber around the rubber supply port 321 is broken, the split sleeve 210 holds the inner pipe 110 firmly. . For this reason, the product 100 is reliably left in the lower mold 200 without moving together with the upper mold 300.

  When the upper mold rises to a predetermined position, the product 100 is discharged from the lower mold 200. At this time, the outer diameter of the upper end of the split sleeve 210 is smaller than the inner diameter of the inner pipe 110 so that the product 100 can be easily detached from the split sleeve 210. The product 100 may be discharged manually, but in the mold according to the present embodiment, the product 100 is automatically discharged by a discharge means (not shown). As described above, the product 100 shown in FIGS. 7 and 8 is obtained.

[Use of mold]
The molding die of the present invention can be used for molding various products in which a gap between an inner pipe and an outer pipe is filled with rubber and crosslinked. As such a product, a shock absorber used for suppressing torsional vibration is exemplified. Especially, like a steering bush, it is suitable as what shape | molds the precision product requested | required that the center axis | shaft of an inner side pipe and the center axis | shaft of an outer pipe match | combine with high precision.

It is sectional drawing which showed the state which cut | disconnected the shaping | molding die of this invention in the surface containing the central axis when the upper mold | type 300 and the lower mold | type 200 are open. FIG. 2 is an enlarged cross-sectional view of a peripheral portion A of a split sleeve 210 in the mold of FIG. It is sectional drawing which showed the state which cut | disconnected the shaping | molding die of this invention in the surface containing the central axis when the upper mold | type 300 and the lower mold | type 200 are closed. FIG. 4 is an enlarged cross-sectional view of a periphery A of a split sleeve 210 in the mold of FIG. 3. It is the perspective view which showed the division | segmentation sleeve 210 in the shaping | molding die of FIGS. 1-4. It is the perspective view which showed the state which cut | disconnected the division sleeve 210 in the shaping | molding die of FIGS. 1-4 in the surface containing the central axis. It is the perspective view which showed the product 100 shape | molded by the shaping | molding die. It is the perspective view which showed the state which cut | disconnected the product 100 shape | molded with the shaping | molding die by the surface containing the central axis. It is sectional drawing which showed the state which cut | disconnected the conventional shaping | molding die when the upper mold | type 300 and the lower mold | type 200 are closed by the surface containing the central axis. FIG. 10 is an enlarged cross-sectional view of a peripheral portion A of a positioning core 210 in the mold shown in FIG. 9.

Explanation of symbols

100 products (buffers)
110 Inner pipe 120 Outer pipe 130 Rubber 200 Lower mold 210 Split sleeve (positioning core)
211 Divided Piece 212 Base 213 Perforated portion 214 Thin portion 215 Perforated portion 216 Narrow portion 217 Slit 300 Upper mold 310 Spreading core 320 Rubber supply path 321 Rubber supply port

Claims (4)

  A lower die provided with a split sleeve for externally fitting and positioning the inner pipe, in which a rubber is filled in the gap between the inner pipe and the outer pipe arranged coaxially to crosslink the inner pipe; And an upper die provided with a spreading core for entering the inside of the dividing sleeve and spreading the dividing sleeve in the radial direction, and when the upper die and the lower die are closed, the inner peripheral surface of the inner pipe is A molding die characterized in that it is strongly restrained by the outer peripheral surface of the split sleeve.   The mold according to claim 1, wherein the split sleeve has a plurality of split pieces having a fixed lower end and a free upper end, and the plurality of split pieces are arranged annularly around the central axis of the split sleeve.   The mold according to claim 2, wherein a thin portion is provided in the vicinity of the lower end of the divided piece.   The mold according to claim 2 or 3, wherein a narrow portion is provided near the lower end of the divided piece.

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