JPS60106903A - Method and device for roller pressing of sintered metallic material - Google Patents

Abstract

PURPOSE:To suppress the protrusion of a sintered metallic member to the outside of a die to a negligible level by retreating the parts for forming the side faces of the die in the pressurizing direction by a roller device with a reduction in the size of the sintered metallic material by pressurization. CONSTITUTION:Parts 31, 32 for forming the bottom surface and side surfaces of a die and the space partitioned by a roller 42 are so set as to attain the finishing size of a sintered metallic member when a roller device 4 is lowered down to the position limited by a stopper 34 in the stage of working said member by a roller pressurizing device 1. The device 4 is once risen and the member 2 is contained into a die 3. The parts 32 are risen by means of springs 35 to the height above the top surface 21 of the member 2. When the roller 42 is slid while the top surfaces of the parts 32 and the member 2 are pressed by the descending roller, the member 2 is compacted at the surface 21 and is reduced in a vertical direction. Since the parts 32 are supported by the springs 35, said parts are retreated by the roller 42 and therefore the member 2 is deformed while the side faces are supported by the parts 32 and the protrusion to the outside of the die is limited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roller pressing method and apparatus for improving the dimensional accuracy of a sintered metal member and increasing the green density of the surface.

In the sintered state, the sintered metal member has many voids and has insufficient dimensional accuracy. Sizing and coining are sometimes carried out to improve these conditions, but since they require large pressure and associated large-scale equipment,
Instead of these methods, a method using a pressure roller is often adopted, which can improve dimensional accuracy and achieve the necessary densification with a low-pressure, simple device. However, the conventional method using a pressure roller had the following drawbacks.

For example, as shown in Figure 1, the processed material (A) is gold M (T!
The surface (
D) When aiming to increase density and improve overall dimensional accuracy,
The disadvantage was that the processed upper part was deformed and protruded from the mold as shown in Figure 2. Also, as shown in Figure 8, the processed material (8'
) If the upper part is made into a pointed shape, mold force and protrusion of the mold can be prevented, but as shown in Figure 4, gaps remain and the density of the surface (ff) is insufficiently increased, resulting in uniform h density. It had nine drawbacks.

The present invention eliminates the drawbacks of the prior art, such as 1, suppresses the protrusion of the processed material outside the mold to a negligible level, improves dimensional accuracy, and achieves uniform densification of the surface. An object of the present invention is to provide a method and apparatus for roller processing a sintered metal member.

The object of the present invention is to provide a roller pressing method for a sintered metal member that improves dimensional accuracy and densifies the sintered metal member by pressing a part of the surface of the sintered metal member housed in a mold with a roller device. , A pressurized surface of the surface of the sintered metal member that is pressurized by the roller device and a mold side forming portion that supports the side surface adjacent to the pressurized surface are rolled by the roller device and under pressure. The mold and the roller device are relatively moved while being vibrated, and the roller device presses the sintered metal member, and as the member is shortened by the pressure, the side surface forming portion of the mold is pressed against the roller. A method for applying roller pressure to a sintered metal member, or a roller device, the method comprising: causing the roller device to move backward in the pressing direction to maintain contact under pressure between the roller device and the pressurized surface of the sintered metal member; and a mold for storing a sintered metal member, and while the sintered metal member stored in the mold is brought into contact with the roller device under pressure, the roller device and the 1917 mold are relatively connected. A roller pressing device for a sintered metal member that moves to press the sintered metal member, and a side surface of the mold that is adjacent to the pressure surface of the 111 p-ra device in the 1 sintered metal member. It is rapidly formed by a roller pressing device of a sintered metal member, which is characterized in that the surface forming portion of the mold I1 to be supported is supported by a spring and is retractable in the roller device pressing direction.

Regarding the relative movement of the roller device and the mold,
Power only the roller device or move only the mold,
Alternatively, either one may be adopted, such as moving both.

According to the method of the present invention, as the sintered metal member is shortened by pressure, the side surface forming portion of the mold is moved back in the pressing direction by the roller device, so that the sintered metal member has a side surface adjacent to the pressurized surface. is pressed by the roller device while being supported by the side surface forming portion of the mold. Therefore, even if the vicinity of the pressurized surface does not have a pointed shape, the protrusion to the outside of the mold can be suppressed to a negligible level, and it is possible to obtain the same accuracy as the one-method method and uniform densification of the surface.

Further, according to the apparatus of the present invention, of the ltf+ recording mold, the mold side surface forming portion that supports the side surface of the sintered metal member adjacent to the roller device pressing surface is supported by a spring in the roller device pressing direction. Since the surface forming portion of the mold 1llI is retracted in the pressing direction by the roller device as the sintered metal member is shortened by pressure, the sintered metal member is retracted from the pressurized surface. The side surface adjacent to the mold is pressed by the roller device while being supported by the side surface forming part of the mold, and as described above, protrusion outside the mold can be suppressed to a negligible level or less, and dimensional accuracy can be improved. improvement and uniform ilk density on the surface can be obtained.

The method and device of the invention will now be explained in more detail based on examples shown in the accompanying drawings.

Roller pressure device (1) and sintered metal member (2) shown in Figure 5
) and a roller device (4).

The roller device (4) includes a roller (6) driven and rotated by an appropriate drive device via the shaft case 11, and a shaft (4N).
The frame supporting the roller (4) is configured to slide against the mold (3) in accordance with the forward and reverse rotation of the roller (4 forces).

The mold (3) includes a lower surface forming portion all, a side surface forming portion @L frame C (3), a stopper, and a compression coil spring 4. The lower surface forming portion (elf) is capable of sliding in the pressing direction relative to the frame body. The side surface forming part is a sintered metal member (2) housed in a mold (3).
It is formed so as to support the surface (2) adjacent to the pressurized surface Qυ.

Furthermore, the side surface forming part □□□ is a roller (
4 is supported so as to be slidable in the bending direction, and is biased by a compression coil spring 4'411 in a direction against the pressure of the roller 0'lJ. The stopper is mounted on the frame (G) and is configured to come into contact with the descending frame decoy to limit the downward movement AY of the roller @2 to a certain level.

When processing is performed using the roller pressurizing device (1), first, when the roller device (4) descends to the position restricted by the stopper, the bottom surface forming portion (-), the side surface forming portion (c), and the roller The position and dimensions of each part are selected and set so that the space partitioned by (6) corresponds to the finished dimensions of the sintered metal member. Next, the p-ra device (4) is once pulled up and the sintered metal member (2) is placed in the mold (3).

In this state, the side surface forming part @ force must be raised by the spring diagram to at least the same height as the top surface of member (2), but in order to ensure the support of the side surface of member (2), It is desirable that it be raised slightly above the top surface. Next, the roller (6) is lowered and rotated in forward and reverse directions as appropriate to slide the side surface forming portion (to) and the upper surface of the member (2) while applying pressure. The downward pressure due to this pressurization is supported by the bottom surface forming portion, and the horizontal pressure is supported by the side surface forming portions.

Due to the sliding motion of the rollers (4) under pressure, the surface eυ of the member (2) becomes denser, and the member (2) deforms along the mold surface, approaches the finished dimension, and gradually shortens in the vertical direction. Since the side forming member (support) is supported in the pressing direction by the springs 0~, it is moved backward by the rollers 0~ as the member (2) shortens.Therefore, the member +2+
With the Fi side surface supported by the side surface forming portion 9, the surface @υ is pressed and deformed by the roller 04, thereby restricting protrusion to the outside of the mold. Strictly speaking, l is the same height as the upper surface of the side forming part (goods) and the lower end of the roller (b), and the amount of member deformation due to one roller movement than the height of the roller ← no traveling direction part on the upper surface of member (2). Although it will be slightly lower, by adjusting the roller pressing force and appropriately reducing the amount of member deformation due to one roller movement, the side surface of member (2) is substantially supported by the side surface forming portion (c). It is possible to process it in a state where it is When the machining progresses and a predetermined amount of shortening occurs, the frame (41) comes into contact with the stopper, and the descent of the rollers is stopped.The member (2) is removed from the mold (3) by the roller device (41). After raising 4), the lower surface forming portion 1311 is raised as shown in FIG.

FIG. 7 shows a device (5) for roller processing the end face of a cylindrical sintered metal member (6). Corresponding to the shape of the member (6), the lower surface forming portion υ1) of the gold m (7) is cylindrical, and the side surface forming portion has two portions (72A) and (72B).
) are formed as springs (75A) and (75B) respectively.
It is supported as mentioned above. Laura Sou yi (8
1 includes two rollers (82A) and (82B),
It is said to be rotatable around the center axis in the vertical direction. When processing the member (6) using this roller pressure device (5), the rollers (82A) and (82B) are rotated in opposite directions and the roller device is rotated around the vertical center axis. You can do the same thing as above except for . After processing, it can be taken out from the lower surface forming part fl)K as shown in FIG.

FIG. 9 shows a device w (9) for roller processing the surface of a sintered metal member (1o) having a stepped portion at the bottom. In this example, the side forming portion (112) is formed to support the surface (102) adjacent to the pressurized surface (101), and the downward pressure due to the pressure applied by the roller (122) is applied to the lower portion forming portion (112). It is supported by the part (111) and the frame (11B), and the pressure in the horizontal direction is applied by the side forming part (112) and the frame (118).
) is supported by Processing using this roller pressure device can be performed in the same manner as described above, and after processing, the member (1o) can be taken out as shown in FIG.

On each of the above sides, compression coil springs were used to support the side surface forming portion of the mold in order to retract the side forming portion of the mold in the direction of roller pressure as the sintered metal member was shortened due to roller pressure. An appropriate spring device such as a spiral spring or an air spring can be used for the support. Alternatively, the FJIJ advance and retreat of the side forming member in the roller pressing direction may be performed by an appropriate control device such as a hydraulic device.

The method and apparatus of the present invention can also be applied when the pressurized surface of the sintered metal member is a gently curved surface. In this case, when supporting the side surface forming portion with a spring in the roller pressure direction, it is recommended to increase the spring force so that the side surface forming portion can move up and down in response to the vertical movement of the roller due to the unevenness of the processed surface. desirable.

Thereby, it is possible to process the member not only when the upper surface of the side surface forming portion is previously formed in a shape corresponding to the curved surface of the IFI member, but also when the upper surface is flat as in the illustrated example.

By chamfering the edge of the pressurized surface of the sintered metal member with a small chamfer of about 0.5C, it is possible to more effectively prevent the member from protruding outside the mold. Mold wear can be prevented.

Examples of the present invention are listed below.

Example composition 1.0fifi%C, M part Fes density 7. Ofl/
Cylindrical sintered iron with dimensions shown in Table 1 "Before treatment" in cm8, inner diameter 88.90 mm, core diameter 25.90 fF
Using an lff+ mold, the end face of the cylindrical sintered iron was pressed with a roller.

The results obtained by the method and apparatus of the present invention are shown in Tables 1 and 2, No. 1
-8, the results obtained by the conventional method and apparatus are shown in number 4.

In Table I V (1 measurement tube), "upper" means within 2 nm from the top surface of the sample, "middle" means within ±1fnfn from the vertical center of the sample, and "10 parts" means within 2 mm from the bottom surface of the sample. Sample No. 4 has a pointed upper surface, and the "upper" dimension indicates the dimension on the upper surface.

As is clear from Table 1, according to the method and apparatus of the present invention,
Even without making the upper surface of the member into a pointed shape, the same improvement in dimensional accuracy as before was achieved. This improvement in dimensional accuracy is number 1
This was achieved even with a lower pressing force than before. Furthermore, there was no protrusion of the member into the mold due to processing.

Table 2 shows the hardness of each part of the sample after processing in terms of Vickers hardness (test load: 10 kg). The higher the hardness, the greater the degree of densification, and the smaller the variation in hardness, the more uniform the densification.

Among the "measurement points" in Table 217C, the "outer diameter part" is a position 1±0.5 mm from the outer surface of the sample, the "center part" is the center part in the thickness direction of the sample, and the "inner diameter part" is 1±0.5 mm from the inner surface of the sample. 0.5 m
Indicates the position of m. "Depth" indicates the distance measured downward from the pressure applied surface force of the member.

As is clear from this table, the variation in hardness is smaller compared to that produced by the method and apparatus of the present invention than by the conventional method and apparatus, and the hardness increases more generally closer to the surface. Therefore, it can be concluded that densification is sufficiently and uniformly performed. These effects were achieved even in sample number 1, where the applied force was lower than the conventional one.

[Brief explanation of the drawing]

Figures 1 to 4 illustrate the main parts of the apparatus for carrying out the conventional method together with sintered metal members. Fig. 8 is a longitudinal sectional front view showing the state before processing of another example, Fig. 4 is a longitudinal sectional front view showing the state during processing, and Figs. 5 to 1θ are the main views. Main parts of an example of an apparatus for carrying out the invention method are shown together with a sintered metal member, and FIGS. 5, 7 and 9 are longitudinal sectional front views showing states during processing in different examples, and FIG. FIG. 6, FIG. 8, and FIG. 10 are longitudinal sectional front views showing the state after processing corresponding to FIGS. 5, 7, and 9, respectively. 111, +61, +91... Roll pressure device, +21, 161, (+01... Sintered metal member, 131, +7), (Jl)... Mold, nl
, is) , O■... Laura! ! ! Hall, shiυ,
(101)...Pressure surface, (to), (102)...Next to the pressure surface, C911
, (7υ, (111)...mold bottom surface forming part, ff
121, (72A), (IIB), (11
2)...Mold side surface forming part, Ha, (82A), (82B), (122
) ... - Low 5° (or more) Figure 1 Figure 2 Figure 3 Rod 4 Figure 1151 1 Brush 61 1 Figure 7 Figure 814! 9. Funeral diagram 10

Claims (1)

[Claims] ■ A roller pressing method for sintered metal parts that improves the dimensional accuracy of the sintered metal parts and improves the edge density by applying pressure with a roller device to a part of the surface of the sintered metal parts placed in the mold. The metal surface is brought into contact with the roller scissors under pressure between the pressurized surface that is pressurized by the roller device and the side surface forming part of the mold that supports the side surface adjacent to the pressurized surface. By relatively moving the mold and the roller device, 60 U! Pressure is applied to the sintered metal part, and as the member is shortened due to the pressure, the side surface forming part of the mold is reduced to 0.
11. A method for pressing a sintered metal member with a roller, which comprises: moving the roller back in the pressing direction using a roller device to maintain contact under pressure between the roller device and the pressurized surface of the sintered metal member.
■ A roller device and a mold for storing a sintered metal member are provided, and the roller device and the mold are moved relative to each other while the sintered metal member stored in the mold is brought into contact with the roller device under pressure. a roller pressing device for a sintered metal member that presses the sintered metal member by moving the sintered metal member; A roller pressing device for a sintered metal member, characterized in that a side surface forming portion is supported by a spring and is retractable in the roller device pressing direction.