JPS5925642B2 - Flexible graphite particle forming equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to an apparatus for forming flexible graphite particles.

More specifically, the present invention relates to a flexible graphite particle molding apparatus that can obtain a graphite molded body without blistering or peeling due to residual air, and has a short effective mold length.

Conventionally, lightweight caterpillar-shaped flexible graphite particles (hereinafter referred to as It is known that graphite particles (often referred to simply as graphite particles) have excellent compression moldability and can easily be formed into sheet-like or block-like molded products when pressed alone or mixed with a binder.

Furthermore, these molded bodies have excellent heat resistance, chemical resistance, and lubricity, and are widely used as gaskets and backings in various mechanical devices, automobiles, and the like.

However, graphite particles generally have a bulk density of 0.01 f/C
12. It is a lightweight particle of less than 12, and is a number? Since even a slight pressure of /cri or less becomes lumpy, it is difficult to fill the material during molding, and the molded product is likely to be non-uniform.

Furthermore, since it is easily compressed, a considerably large mold is required when molding a thick-walled product, which has the disadvantage of causing restrictions in processing and increasing mold production costs.

For example, bulk density 0, 01? If you want to obtain a compact with a density of 101/c4 by compressing flexible graphite particles with a particle size of less than /crd, you will need a mold with an effective length that is at least 100 times the length or thickness of the desired compact. It becomes necessary.

For this reason, when trying to obtain a backing etc., graphite particles are first made into a sheet by roll forming, as shown in JP-A-54-122693, and then the sheet is processed using a cross-cut shredder (shredder). ) is generally used to supply the pulverized material to a mold and press-form it.

However, in this method, it is necessary to first roll form a sheet and crush it, which is not only time-consuming but also impairs the adhesive strength of flexible graphite, which reduces the mechanical strength such as radial crushing strength. You can only get weak ones.

Therefore, the present inventors previously applied for patent application No. 54-118140.
As shown in , a molding method is provided in which graphite particles are compressed and filled into a mold by using a horizontal screw extruder to obtain a graphite molded body having a length or thickness of 20 to 30% of the effective length of the mold. Proposed.

In this method, the graphite particles are uniformly compressed and supplied to the mold, so that the resulting molded product has uniform physical properties and excellent mechanical strength.

However, even with this method, the graphite particles filled into the mold still have a small bulk density and contain a large amount of air.If the graphite particles are press-molded while containing a large amount of air,
This had the disadvantage that air remained between the graphite layers, causing blistering and peeling.

Furthermore, since a horizontal screw extruder and a compressed body are used, it is extremely disadvantageous for mass production.

Therefore, the present inventors have developed a mass-production method that has the advantage of obtaining a graphite molded body having a length or thickness of 20 to 30% of the effective length of the mold, while also being able to eliminate air contained in graphite particles. The present invention was arrived at as a result of intensive research into molding equipment suitable for this purpose.

Therefore, one object of the present invention is to provide an apparatus for efficiently obtaining a graphite molded body without causing blistering or peeling due to residual air.

Another object of the present invention is to provide a graphite molding apparatus suitable for mass production using the above-described method and having a short effective mold length.

These and other features, features and benefits will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

Basically, according to the present invention, there is provided a flexible graphite particle molding apparatus having a screw extruder having a molding die removably attached to the tip thereof, wherein the extruder is a vertical screw extruder. , wherein at least one hole communicating from the inside to the outside is provided in the wall of the cylinder housing the screw for conveying the flexible graphite particles in the vertical screw extruder. A molding device is provided.

Furthermore, according to the present invention, in the flexible graphite particle molding apparatus having a screw extruder having a molding die removably attached to the tip thereof, the extruder is a vertical screw extruder, and the vertical screw extruder is a vertical screw extruder. At least one hole communicating from the inside to the outside is provided in the wall of the cylinder housing the screw for conveying the flexible graphite particles in the extruder, and the molded body is in contact with the compact after compression molding on the inside wall of the mold. There is provided an apparatus for molding flexible graphite particles, characterized in that at least one hole is provided in the wall portion of the prosthetic mold corresponding to the portion where the mold is not formed, so as to communicate the inside and outside of the mold.

The invention will now be described with reference to the accompanying drawings.

FIG. 1 shows an overall view representing one embodiment of the apparatus of the present invention.

FIG. 2 is a front view of the main parts of the apparatus shown in FIG. 1.

Four molds 1 are installed on the same circumference on a rotary disk 2 at equiangular positions of 90°.

The mold 1 is provided with at least one hole 19 in a wall portion of the mold 1 corresponding to a portion of the inner wall surface that does not contact the molded product after compression molding, for communicating between the inside and outside of the mold. There is.

The center of the rotating disk 2 is supported by a cylinder 4 fixed to the base 3, and a shaft attached to the center of the rotating disk 2 is passed through the inside of the cylinder 4. By rotating the shaft, the rotating disk 2 is rotated. Rotate.

On the fixed plate 5, a vertical screw extruder 6, a press cylinder 7, and a take-out cylinder 8 are located directly above the cylinder in which the mold 1 on the rotary plate 2 is installed, and have the same radius as the circumference. They are placed at equal angles of 90° on the circumference.

The extruder 6 is provided with at least one hole 19 communicating from the inside to the outside in the cylinder wall housing a screw for transporting flexible graphite particles.

The fixed platen 5 is attached to a support 9 fixed to the base 3.

A lower punch cylinder 10 is installed directly below the position of the mold 1 fixed to the rotary disk 2.

The indexing pin 15 operates every time the rotary disk 2 rotates 90 degrees to fix the rotary disk 2.

As the rotary disk rotates 20 times, the mold on the rotary disk 2 also moves 90 degrees, but the index pin is set so that the mold 1 stops directly below the vertical screw extruder 6, press cylinder 7, and take-out cylinder 8. 15 is activated.

The vertical screw extruder 6 can be moved up and down using conventional technology.

A press punch is installed inside the press cylinder γ, a take-out punch is installed inside the take-out cylinder 8, and the press punch moves inside the press cylinder 7.
The take-out punches each move up and down within the take-out cylinder 8.

When the rotary disk 2 is fixed by the index pin 15, the vertical screw extruder 6 descends, and the vertical screw extruder 6
The discharge port surface 11 and the upper surface 12 of the mold are brought together.

As shown in FIG. 4, a lower receiving die 13 is attached to the tip of the lower punch rod 14, and the lower bunch rod 14 and the lower receiving die 13 move up and down within the lower punch cylinder 10 as a unit.

The operation and effects of the device configured as described above will be explained.

When the rotary disk 2 is fixed by the index pin 15, the vertical screw extruder 6, the press punch, and the take-out punch descend.

When the discharge port surface 11 of the vertical screw extruder 6 and the mold upper surface 12 are brought together at station I20 shown in FIG. The screw 17 rotates,
The flexible graphite particles 24 supplied from the hopper 18 are transferred to the molding die 1 by the screw 17 .

FIG. 4 shows a sectional view of the molding die 1, and FIG. 5 shows the vertical screw extruder 6.

When the graphite particles 24 are conveyed by the screw of the vertical screw extruder 6, deaeration is performed through holes 19 provided in the cylinder wall of the extruder 6.

Also, since the screw extruder is a vertical type, the graphite particles 24
When transported by a screw, it is uniformly filled into the mold 1 by gravity.

Furthermore, the graphite particles 24 which have been deaerated and have increased bulk specific gravity in the vertical screw extruder 6 shown in FIG. The air is further degassed through the holes 19 provided in the wall of the mold 1,
Uniform filling of graphite particles becomes possible.

Note that the diameter of the holes in the cylinder wall of the vertical screw extruder and the wall of the molding die varies depending on the particle size of the graphite particles used, but generally they are 0.5 m or more and 3 W or less,
Preferably it is 1 mm or more and 2 ran or less.

However, the shape of the hole is not limited and may be circular or any other shape.

In the present invention, a screw with a compression ratio is used in order to improve degassing from the holes in the cylinder.

However, if the compression ratio is too large, the flexible graphite particles 24 will become block-shaped inside the extruder, which is not preferable.

If the compression ratio is 1.0, only a short molded body can be obtained with respect to the effective length of the mold, and the degassing effect is also small.

Preferred compression ratios are as follows. [Shape of molded object]
[Screw compression ratio] Round bar or square bar
1.5-3.5 pipe (wall thickness, less than 2mm)'1.
0 to 1.5 [Shape of molded body] [Screw compression ratio] Pipe (wall thickness 2 mm to 5 mm) 1.3 to 2.0
Pipe (thickness 5W or more) 1.5 to 2.5 The measurement of graphite particles is controlled by the rotation speed and rotation time of this screw.

At station I21, a press punch attached to the tip of a press cylinder rod is lowered by pressure fluid, and at station I20, the flexible graphite particles 24 filled in the mold 1 are compressed and molded.

The press cylinder rond is controlled by a counter so as to reciprocate an arbitrary number of times using pressure fluid, thereby preventing spring breakage of the flexible graphite molded body.

At station llI22, lower puff f cylinder rod 1
The lower receiving mold 13 attached to the tip of the lower part 4 is lowered via pressure fluid.

Thereafter, a take-out punch attached to the tip of the take-out cylinder wall is lowered via pressure fluid to take out the flexible graphite molded body.

When the flexible graphite molded body is a solid body, the vagina molded body remains in the mold 1 after compression molding and can be taken out.

When the molded body is a hollow body, providing a slight draft angle to the core 16 ensures that the molded body remains in the mold and can be taken out.

At station 23, the inside of the mold 1 is cleaned with compressed air or suction air.

The lower receiving mold 13 attached to the tip of the punching bunch rod 14 rises via the pressure fluid.

The operations at stations I, II, ■, and ■ described above are performed simultaneously in parallel, and when all operations are completed, the index pin 15 is removed, and the drive device moves the rotary disk 2 horizontally to 90 degrees.
When the rotary disk 2 is rotated by 0° and fixed by the index pin 15, the above-described operations are repeated at stations I, II, III, and IV, and flexible graphite molded bodies are continuously obtained.

The above operations are fully automated.

Of course, the apparatus of the present invention can also be used when compression molding of individual graphite molded bodies is performed one by one without automation as described above.

In the present invention, as a material, Japanese Patent Application No. 55-57781 is used.
Flexible graphite granules for molding shown in are preferably used.

When using the granules with a bulk density of 0.03 S'/c4, the density is 1.5 mm with a length that is 50 to 70 times the effective length of the mold.
0? /c4 molded body, density 1. with effective mold length.
It is also possible to obtain molded bodies of 5P/c4.

In the present invention, graphite particles and graphite granules are similarly referred to as ffi graphite particles.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the scope of the present invention is not limited to the Examples.

Example 1 The bulk density of the material was 0.01 f/crA, and the screw compression ratio was 1:1. The mold has an outer diameter of 15mm, an inner diameter of 10ynm, and a length of 7mm.
0rrrrn, pipe mold, press pressure (station [I) is 7 Kg / c with a pneumatic cylinder with a diameter of 100wn
Compression molding was performed using the above-mentioned apparatus under the conditions of d.

The results are shown in Table 1.

Example 2 The bulk density of the material is 0.01 f/c4, the screw compression ratio is l:1.3, the mold has an outer diameter of 15 mm, an inner diameter of 10, a length of 70 rrarL1 pipe mold, and a press pressure (station [1)] 7Kg/c with 100m+n diameter pneumatic cylinder
Compression molding was performed using the same equipment as in Example 1 under nAL conditions.

The results are shown in Table 2.

Example 3 Is the bulk density of the material 0.01? /cni, screw compression ratio is 1:1.5, mold is outer diameter 15mm, inner diameter 10mm1
Compression molding was carried out using the same equipment as in Example 1 using a pneumatic cylinder with a length of 70 rIrJrL, a pipe mold, and a press pressure (Stay Shore 11) of 100 rrrrrL diameter at 7 kg/crrt.

The results are shown in Table 3.

Example 4 Material bulk density is 0.03 f/crll, screw)-
The compression ratio is 1:1, the mold is a pipe mold with an outer diameter of 15 mm, an inner diameter of 10-1, and a length of 70 rrvns.
Compression was carried out using the same equipment as in Example 1 under the following conditions.

The results are shown in Table 4.

Example 5 The bulk density of the material was 0.03 S'/cfl, the screw compression ratio was 1:1.3, the mold had an outer diameter of 15 mm, an inner diameter of 1 ONn, a length of 70 mm, a pipe mold, press pressure (station [I
) is 7 to 9/cWI with a 100 mm diameter pneumatic cylinder.

Compression molding was performed using the same equipment as in Example 1 under the following conditions.

The results are shown in Table 5. Example 6 The bulk density of the material was 0.03 S'/crA, the screw compression ratio was 1:1.5, the mold had an outer diameter of 15 mm, an inner diameter of 10 m,
Length 70mm, pipe mold, press pressure (station [I) is 7Kg/crr with a 100mm diameter pneumatic cylinder
Compression molding was performed using the same equipment as in Example 1 under the conditions of f.

The results are shown in Table 6.

Example 7 Material bulk density is 0.01 t/cfl, screw compression ratio is 1:1.3, mold has outer diameter of 15 mm, length of 70 m, round bar mold, press pressure (Station II) is 100 mm diameter. Compression molding was performed using the same equipment as in Example 1 under the conditions of 7 Kg/c4 in a pneumatic cylinder.

The results are shown in Table 7.

Example 8 The bulk density of the material is 0.03 ff/crA, the screw compression ratio is 1:1.3, the mold has an outer diameter of 15 mm and a length of 70 mm1.
Example 1 with a round bar mold, press pressure (station [[) is a pneumatic cylinder with a diameter of 100 cm and conditions of 7 to 41 ctyi]
Compression molding was performed using the same equipment.

The results are shown in Table 8.

A brief description of the drawing.

Figure 1 is a schematic diagram of the entire flexible graphite particle forming apparatus, Figure 2 is a front view of the main parts of the flexible graphite particle forming apparatus, and Figure 3 is a plan view of the main parts of the flexible graphite particle forming apparatus. A schematic diagram, FIG. 4 is a sectional view of a molding die, and FIG. 5 is a fragmented sectional view of a vertical screw extruder.

1... Molding mold, 6... Vertical screw extruder, 1
9... Holes, 24... Flexible graphite particles.

Claims (1)

[Scope of Claims] 1. A flexible graphite particle molding device having a screw extruder with a molding die removably attached to its tip,
The extruder is a vertical screw extruder, and at least one hole communicating from the inside to the outside is provided in the cylinder wall housing the screw for conveying the flexible graphite particles in the vertical screw extruder. A flexible graphite particle molding device characterized by: 2. In a flexible graphite particle molding device having a screw extruder with a molding die removably attached to the tip,
The extruder is a vertical screw extruder, and at least one hole communicating from the inside to the outside is provided in the cylinder wall housing the screw for conveying the flexible graphite particles in the vertical screw extruder, Further, at least one hole is provided in the wall portion of the mold corresponding to a portion of the inner wall surface of the mold that does not contact the molded product after compression molding, for communicating between the inside and outside of the mold. A device for molding flexible graphite particles.