JPH0242319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a dry cold isostatic pressurizing apparatus for pipe forming.

<Prior art> A dry cold isostatic pressure device (hereinafter referred to as a dry CIP device) for pipe forming uses a molded rubber mold and a mandrel concentric with the molded rubber mold between upper and lower punches that close the upper and lower ends of a molded container. A pipe is formed by filling the space between the powder materials and applying ultra-high pressure to form a pipe. This method is already well known from Japanese Patent Application Laid-Open No. 49-33273.

<Problems to be Solved by the Invention> However, this is a top extraction method in which after the pipe is formed, the pipe is lifted above the molded container using a lower punch and the pipe is taken out from the upper side of the molded container. The punch needs to be larger than the length of the molded container. Therefore, when forming long objects,
There are limitations in terms of the buckling stress of the lower punch, etc., and there are also disadvantages in that the entire length of the lower punch must be replaced when changing the size of the molding rubber mold.

<Means for Solving the Problems> The present invention solves these conventional problems, and as a specific means for that purpose, molded rubber is inserted between the upper and lower punches that close the upper and lower ends of the molded container. In a dry cold isostatic pressurizing device for pipe forming, which is equipped with a mandrel that passes vertically inside the mold, the mandrel is provided so as to pass through the lower punch in a vertically slidable manner, and this mandrel is placed on the lower side of the lower punch. and is supported by a mandrel device, and is provided with a lifting drive device for independently raising and lowering the lower punch and the mandrel device, so as to transmit the forming axial force applied to the lower punch to the yoke frame via the mandrel device, The mandrel device is provided with a backup cylinder.

<Operation> During pressure molding, a pressure medium is introduced between the molding container 1 and the pressurizing rubber mold 8 in the state shown in FIG. 1, and the powder 19 is pressurized from the entire circumference via the molding rubber mold 7. .
At this time, the forming axial force acting on the upper and lower punches 9, 11 is transmitted to the yoke frame 17 and is borne by it.

After molding, the lower punch 11 and mandrel 13 are lowered as shown in FIG.
is lowered and extracted downward from the pipe 20 as shown in FIG. 3, and then the pipe 20 on the lower punch 11 is
Take it out to the outside.

<Example> Hereinafter, the present invention will be described in detail with reference to the illustrated example. In the figure, reference numeral 1 denotes a molded container, which is fixedly supported by a vertical frame 4 of a base frame 3 via a container frame 2. A molding rubber mold 7 and a pressurizing rubber mold 8 are mounted inside the molding container 1 by means of upper and lower outer covers 5 and 6 at both ends thereof. Reference numeral 9 denotes an upper punch, which is attached to an upper punch frame 10 that is supported by the vertical frame 4 so as to be movable up and down, and is inserted into the upper outer lid 5 of the molded container 1 from above so as to be detachable. Reference numeral 11 denotes a lower punch, which is attached to a lower punch frame 12 that is supported by the vertical frame 4 so as to be movable up and down, and is inserted into the lower outer lid 6 of the molded container 1 from below so as to be able to fit in and out. A mandrel 13 is inserted through the lower punch 11 so as to be vertically slidable, and is attached to a mandrel frame (mandrel device) 14 below the lower punch frame 12. The mandrel frame 14 is movable up and down along the vertical frame 4. Vertical frame 4
On the side, there is a lower punch elevating cylinder 1 for elevating the lower punch 11 via the lower punch frame 12.
5 and a mandrel lifting cylinder 16 for lifting and lowering the mandrel 13 via the mandrel frame 14, these lower punch 11 and the mandrel 1
3 are installed so that they can be raised and lowered independently. 17 is a yoke frame configured in the shape of a rectangular frame, 18 is a backup cylinder, which is attached to the lower side of the mandrel frame 14,
The forming axial force applied to the lower punch 11 is transmitted to the yoke frame 17 via the mandrel frame 14. 19 is a powder, 20 is a pipe which is a molded body formed from the powder, and 21 is a powder feeding pipe.

In the dry CIP device with the above configuration, the pipe 20
When molding, proceed as follows. FIG. 1 shows the state before molding (pressurization), in which the powder 19 is stored in the molding rubber mold 7, the pressurizing rubber mold 8 and the molding container 1.
Pressure molding is performed using a pressure medium (pressurized by a pressure booster not shown) introduced into the gap between the two. At this time, upper punch 9
The forming axial force applied to the upper yoke frame 17
Furthermore, the forming axial force applied to the lower punch 11 is transmitted and borne by the lower yoke frame 17 via the mandrel frame 12 and the backup cylinder 18, respectively.

When the powder 19 is formed, the yoke frame 17 is opened as shown in FIG. 2, and the lifting cylinders 15 and 16 are extended to lower the lower punch 11 and mandrel 13 along the vertical frame 4. As a result, the molded pipe 20 is pulled out downward from the molded rubber mold 7 of the molded container 1 while being placed on the lower punch 11. Then, when the pipe 20 goes down below the lower outer cover 6, the lifting cylinder 15
By stopping the downward movement of the lower punch 11 and sliding the mandrel 13 downward relative to the lower punch 11, the pipe 20 is extracted downward as shown in FIG. In addition, this is mandrel 13
By making the lowering speed of the lower punch 11 higher than that of the lower punch 11, the lifting cylinders 15 and 16 can be simultaneously operated. Once the mandrel 13 is removed from the pipe 20, the pipe 20 on the lower punch 11 is taken out to the side by an appropriate robot (not shown) or the like.

After taking out the pipe 20, the lower punch 11 is raised to fit into the lower outer cover 6 as shown in FIG.
Powder 19 is supplied into the molding rubber mold 7 through the powder supply pipe 21 so as to protrude slightly upward from the upper surface. In this case, while supplying the powder 19, the mandrel 13 is raised so that the tip of the mandrel 13 is approximately aligned with the level of the molding rubber mold 7, thereby uniformly supplying the powder 19 in an annular shape into the molding rubber mold 7. This makes it possible to prevent the bridging phenomenon from occurring.

Note that the upper punch 9 can be moved up and down along the vertical frame 4 by a lifting drive device (not shown).

In addition, in the embodiment, the lower punch 11, the mandrel 1
Although an elevating cylinder is illustrated as the elevating drive device in No. 3, the elevating cylinder is not limited thereto, and a screw mechanism operated by a motor or the like may be used.

<Effects of the Invention> According to the present invention, as detailed in the embodiment, the mandrel is vertically slidably penetrated through the lower punch,
Since these lower punches and mandrels are raised and lowered independently, the formed pipe can be taken out from the lower side of the molded container. The length is extremely short, making it very convenient even when molding long objects. Also, since the lower punch is shorter, there is no need to replace the entire punch when changing the size, and only the tip of the punch needs to be changed, making the work easier. Furthermore, since the structure is such that the forming axial force of the lower punch is transmitted to the yoke frame via the mandrel device, the lower punch and the mandrel are in an integral relationship during forming, and there is no problem in forming.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
4 through 4 are cross-sectional views showing the same working process. 1... Molded container, 4... Vertical frame, 7... Molded rubber mold, 9... Upper punch, 11... Lower punch,
12... lower punch frame, 13... mandrel, 14... mandrel frame, 15... lower punch lifting cylinder, 16... mandrel lifting cylinder, 17... yoke frame, 18... back up cylinder.

Claims (1)

[Claims] 1 In a dry cold isostatic pressurizing device for pipe forming, which is equipped with a mandrel that passes vertically inside the molding rubber mold between the upper and lower punches that close the upper and lower ends of the molded container, the lower punch is slidably passed through the lower punch. A mandrel is provided as shown in FIG.
1. A dry cold isostatic pressurizing device for pipe forming, characterized in that the mandrel device is provided with a backup cylinder so as to transmit the forming axial force applied to the lower punch to the yoke frame via the mandrel device.