JPS6317883B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention synchronizes a forming press and a straightening press in order to improve dimensional accuracy, improve density, or correct shape as necessary after sintering sintered machine parts. This invention relates to a sheureless sizing method that aims to increase the speed of the sizing process.

Generally, during the recompression process after sintering sintered machine parts, unlike the compression molding process, the sintered body that has already been shaped is recompressed, so how can it be accurately and quickly molded into a mold? An important point in manufacturing technology is whether or not the material can be charged.

Conventionally, the charge method used in recompression processes such as straightening presses for sintered bodies includes a method in which a rotary table or an index table is used to first charge the table, and then the table is intermittently rotated while being charged to a punch center, or a feed system is used. A method is known in which a primary charge is performed at the punch center and then a charge is performed at the punch center. however,
If the punch center is not reliably charged, mischarging will occur, so positional accuracy is required for charging, and as a countermeasure to this, a guide portion is provided.

Furthermore, the travel distance when charging the sintered body to the punch center may be several times the outer diameter of the sintered body, which hinders fast and reliable charging.

That is, FIGS. 1 to 6 are explanatory diagrams showing the steps of charging the sintered compact 01 to the punch center of the die 02 and recompressing it using a feed shoe. First, in Figure 1, show 0
The sintered compact 01 is sequentially dropped from the nozzle 04 holding the sintered compact 01 to the guide No. 3 to complete the primary charge to the show 03. At the same time, the lower punch 05 is raised to extract the straightened sintered compact 01, and movement begins. In FIG. 2, the shoe 03 moves and discharges the straightened sintered body 01, and the shoe 03
is stopped at the punch center, and the sintered body 01 is dropped to the guide portion 0 of the die 02 as shown in FIG.
Charge to 2a is completed.

After that, as shown in FIG.
At the same time as the primary charge is performed, the upper punch 06 starts to descend, and as shown in FIG. 5, the effective diameter portion 02b of the die 02 is pressurized and corrected. Thereafter, as shown in FIG. 6, the lower punch 05 starts to rise, the straightened sintered body 01 is extracted, the shoe 03 starts to move, and one cycle is completed. In addition, in the case of rotary tables and index tables, the charge holes in the table function as die guides.
Generally, the lower punch rotates intermittently when the lower punch is in a flush state after extraction is completed.

As mentioned above, conventional equipment requires a mechanism to transport the sintered compact from the primary charge to the punch center, which is the secondary charge, and the structure is complex, requiring a lot of time for transport, resulting in poor productivity. There were other problems.

The present invention has been made in view of the above-mentioned circumstances, and does not require a complicated conveyance mechanism, shortens the time required to charge the sintered body, and enables accurate and reliable recompression process. This provides a sheerless sizing method.

Embodiments according to the present invention will be described below with reference to FIGS. 7 to 1.
This will be explained in detail based on FIG.

7 and 8 are a top view and a sectional view taken along the line A-A of the main parts of the device according to the present invention, in which 1 is a sintered body, 2 is a Schuless die during recompression, and 3 is a sintered body 1. A shooter which is arranged and fed sequentially by its own weight from a parts feeder, 4 is a charge pusher, 5 is an air cylinder, 6 is a proximity switch,
7 is a lower punch, and the ejection mechanism is omitted.

As shown in FIGS. 9a, b, and c, the Scheureless die 2 is formed into a shape that has a holding part 2b partially cut out in an L shape above the effective diameter part 2a that performs straightening pressing of the sintered body 1. It is incorporated into a sheureless sizing device.

Therefore, the sintered body 1 is sequentially fed into the holding portion 2b of the die 2 from the parts feeder via the shooter 3 and charged.
The sintered body 1 is then placed on the side upper surface of the die 2, and then pushed out through the pusher 4 in a direction perpendicular to the shooter 3 by the operation of the air cylinder 5, and charged into the holding part 2b. There is.

Next, the press cycle in the apparatus configured as described above will be explained in detail based on the show motion explanatory diagrams of FIGS. 10 to 14 and FIG. 15.

In FIGS. 10a and 10b, the sintered body 1 fed from the shooter 3 is pushed out by the pusher 4 and charged into the holding part 2b of the die 2, and the charged sintered body 1 is transferred to the 11th As shown in the figure, the lower punch 7 and the upper punch 8 are operated from above and below to apply pressure, and the cylinder 5 is turned off and the pusher 4 returns to its original position. Next, the 12th
As shown in the figure, the upper and lower punches 7 and 8 move upward to extract the corrected sintered body 1, and the next sintered body 1 is fed in front of the pusher 4. Thereafter, the straightened sintered body 1 is discharged by a discharge mechanism (not shown), and at the same time, the next straightened sintered body 1 is pressed against the side surface of the lower punch 7 by the pusher 4, and as shown in FIG. As the sintered body 1 descends, the sintered body 1 is charged into the holding portion 2b of the die 2, completing one cycle.
At this time, the dynamic pressure in the cylinder is adjusted to a range that does not affect the sintered body by sufficiently reducing the pressure using a pressure reducing valve or the like.

Here, deformation of the sintered compact 1 or the mixing of foreign objects can be detected by a proximity switch 6 installed on the cylinder 5 and a detection rotary cam (not shown) installed on the main shaft to determine whether the cylinder 5 is at its forward limit when the lower punch 7 is lowered. Detection is now possible using a combination of In addition, the solenoid valve connected to the cylinder 5 is set to turn ON when the lower punch 7 is flush with the lower punch 7 during the ejection process, so that the forward limit is reached at the same time as the punch descends, as shown in Fig. 15. The detection timing can be set earlier.

As described in detail above, the sheureless sizing method according to the present invention does not require any special mechanism and has a simple structure. In addition, when charging a sintered body, there is no need for a turntable, a shoe, etc., and a holding part for the sintered body is formed in the die in advance, and the sintered body is fed into the holding part from an inclined shooter. Charging is performed via a cylinder pusher, and the distance the sintered body moves is approximately the length of the product's outer diameter, making the travel time virtually zero.

Therefore, the sintered body can be accurately and quickly charged into a predetermined mold, and the mischarging can be eliminated by the mischarging detection circuit, thereby improving productivity.

[Brief explanation of the drawing]

1 to 6 are explanatory diagrams of the recompression process showing a conventional embodiment, FIGS. 7 to 8 are top views and sectional views taken along the line A-A of the main parts of the apparatus according to the present invention, and FIG. Figures a, b, and c are a top view, a sectional view taken along line B-B, a perspective view, and a 10th
14 are explanatory views showing the recompression process according to the present invention, and FIG. 15 is an explanatory view showing the compression process according to the present invention. 1... Sintered body, 2... Scheures die, 2a...
...Effective diameter part, 2b...Holding part, 3...Shooter,
4... Pusher, 5... Cylinder, 6... Proximity switch, 7... Lower punch, 8... Upper punch.

Claims (1)

[Claims] 1. In the charging method in the recompression process of the sintered body, a holding part having an L-shaped upper surface notched is formed in the upper part of the effective diameter part formed on the die for charging the sintered body, and a shutter is provided on the upper side surface of the die. The sintered compact sent out and placed through the cylinder is extruded in a direction perpendicular to the shooter through the pusher of the cylinder, and charged to the holding part of the die.Then, the sintered compact is pushed through the upper and lower part of the die by a pair of upper and lower punches. A Schewless sizing method, characterized in that the sintered body is transferred to the effective diameter section and recompressed, and then transferred to the upper surface of the die by the punch and discharged.