JP2002322504A - Deburring method and deburring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deburring method capable of removing burrs on inside and outside diameter parts of a sintered body with excellent workability at a low cost while the accuracy of the sintered body is not affected. SOLUTION: This deburring method comprises a step of filling a powder metal in a die, a step of compressing the powder at the predetermined pressure to form a powder molding, a step of heating the powder molding to form a sintered body, a step of restricting the sintered body between a work base 8 and a work holding plate 9, a step in which a movable punch 10 and a punch holder 11 are provided, an elastic body 13 is urged between the movable punch and the punch holder, the movable punch comprises a contact part 102 in contact with the sintered body and a non-contact part 103 not in contact with the sintered body, and the punch holder and the movable punch are moved, and a step in which the movable punch is pushed out by the urging force of the elastic body to remove burrs SB of the sintered body when the contact part is changed from the contact condition with the sintered body to the non-contact condition as the movable punch is moved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deburring method and a deburring apparatus, and more particularly to a deburring method and a deburring apparatus for removing a burr generated by a sintered body by a movable punch.

[0002]

2. Description of the Related Art Conventionally, a ring-shaped part S2 such as an outer race used in an automatic transmission (ATM) for a vehicle as shown in FIG. 5 is filled with a powder metal material in a mold (not shown). Then, the powder compact is formed by compression.

After the step of sintering the powder compact, FIG.
A chamfer (C-plane shape) M1 is formed at the inner (or outer) corner of the sintered body S2 using a mold in a sizing process such as
When forming M2, a mandrel 52 and a punch 4 having a projection M3 for forming the above chamfered shape are provided.
9 and the lower punch 48 also having the protruding portion M4, when the sintered body S2 is restrained and compression-formed, a compressive force is intensively applied to the vicinity of the protruding portions M3 and M4, and breakage of these protruding portions and Deformation occurs. The inner and outer diameters of the sintered body S2 are held by a mandrel 52 and a die 53.

Therefore, in order to form a chamfered shape, as shown in FIG. 1, a sizing die having an upper mandrel 2 formed with an inclined portion 2A and an inclined portion 3A formed on an upper mandrel 2 and a lower mandrel 3. A method is used in which the sintered body S2 is divided into two parts by the sizing mold lower mandrel 3 and the sintered body S2 is compression-formed between the lower punch 38 and the upper punch 39.

However, according to this method, the upper mandrel 2
As the mandrel 3 and the lower mandrel 3 approach each other, the sintered body S2
Bulges into the inner diameter portion of the substrate, and minute burrs SB are generated.
For this reason, a step of removing the burrs SB becomes indispensable.

The above deburring method is disclosed in Japanese Unexamined Patent Publication No.
As described in Japanese Patent No. 37801, there is a method using a rotating brush. In the apparatus using the rotating brush, the green compact 11 with the burr X remaining on the step portion 11b of the outer peripheral side surface 11a is placed on the transport surface 2a of the belt conveyor 2. The rotating brushes 5, 5, 6 are arranged in a zigzag manner on the side of the belt conveyor 2.
The burr X is removed while rotating the green compact 11 by the rotating brushes 5 and 6 while conveying the green compact 11. With this apparatus, deburring of the sintered body is performed inexpensively and efficiently at the stage of compacting. (Note that the above figures are figures in JP-A-8-337801.) As another deburring method, a method of cutting burrs using a cutting tool or the like, or removing fine burrs on a sintered body by removing fine burrs There is a method by a shot to be performed and a method by punching by a punch.

[0007]

However, as described in Japanese Patent Application Laid-Open No. 8-337801, the method using a rotating brush requires a cost, space,
Also, there is a problem that burrs are scattered by the brush, and it is practically impossible to remove strong mold burrs.

[0008] Further, the method by cutting includes fixing a work,
There were problems with the cost, space, and workability of the equipment for cutting.

Furthermore, the shot method has disadvantages such as cost and space due to the equipment of the shot, and deterioration of surface roughness on a surface not related to burrs due to the shot.

The method of punching with a punch can work in an extra space of a sizing press by reducing the size of a mold, and satisfies requirements in both cost and space.
Further, since deburring can be performed by simply positioning the sintered body S2 by the localization plate 7, the work is also easy. FIG. 7
Is a mold view before removing the burrs SB from the sintered body S2 by the punch 6. FIG. The right view of FIG. 7 is a view in which burrs are removed from the sintered body S2 by the punch 6.

However, according to the punching method using the punch 6, the punching burrs SB to be removed fall down on the punch 6 and adhere to the punch 6, the sintered body S2, and the work table 8, as shown in FIG. Further, as shown in FIG. 9, the burrs SB are pressed against the work holding plate 9 or the work table 8 for pulling the punch 6 out of the sintered body S2, and adversely affect the product, such as forming burrs on the next sintered body. There was a problem that exerted.

An object of the present invention is to solve the above-mentioned problems and to provide a method for reliably and inexpensively removing burrs generated in a sizing step.

[0013]

According to a first aspect of the present invention, there is provided a method of filling a metal powder material into a mold, and compressing the metal powder material at a predetermined pressure. Forming a powder compact by heating the powder compact to form a sintered body, constraining the sintered body between a work table and a work holding plate, A punch and a punch holder are provided,
An elastic body is urged between the movable punch and the punch holder, and the movable punch has a contact portion that contacts the sintered body and a non-contact portion that does not contact the sintered body. The step of moving the holder and the movable punch; and, when the contact portion changes from the contact with the sintered body to the non-contact state with the movement of the movable punch, the movable punch is pushed out by the urging force of the elastic body. And removing the burrs of the sintered body.

According to the first aspect of the present invention, the burrs on the inner and outer diameters of the sintered body can be removed without affecting the precision of the sintered body, and the workability is improved because the work is only positioned by the positioning plate. Further, since the size of the mold can be reduced, there is an effect that a low-cost deburring method is provided.

According to a second aspect of the present invention, there is provided a sintered body, a work table and a work holding plate for restraining the sintered body, a stripper bolt fixed to a punch holder. A movable punch that is pushed out of the punch holder by an elastic body, the movable punch is movable in a compression axis direction of the sintered body, and a contact portion that contacts the sintered body and a non-contact portion that does not contact the sintered body. It has a contact portion, and when the movable punch is moved to the non-contact portion as the movable punch moves, the movable punch is configured by the elastic body that sets a biasing force so that the movable punch is pushed out. It is a deburring device.

According to the second aspect of the present invention, burrs on the inner and outer diameters of the sintered body can be removed without affecting the accuracy of the sintered body, and workability can be improved because the work is simply positioned by the positioning plate. Further, since the mold can be reduced in size, there is an effect that a low-cost deburring apparatus is provided.

According to a third aspect of the present invention, which is made to solve the above technical problem, the biasing force of the elastic body set to push the movable punch is such that the biasing force of the elastic body <the shearing force. 3. The deburring apparatus according to claim 2, wherein:

Here, the shearing force is a force acting between the sintered body and the movable punch.

According to the third aspect of the present invention, by setting the biasing force of the elastic body as described above, the burrs on the inner and outer diameters of the sintered body can be easily removed, and the work is positioned by the positioning plate. Therefore, the workability is improved and the size of the mold can be reduced, so that there is an effect of providing a low-cost deburring apparatus.

According to a fourth aspect of the present invention, which has been made to solve the above-mentioned technical problem, the biasing force of the elastic body that is set so that the movable punch is pushed out is smaller than the biasing force of the elastic body.
3. The deburring apparatus according to claim 2, wherein (shearing force + μF). Here, the shearing force is a force acting between the sintered body and the movable punch, μ is a coefficient of friction between the movable punch surface and the sintered body surface, and F is the movable punch and the sintered body. Is the force applied perpendicular to the plane between

According to the fourth aspect of the present invention, by setting the biasing force of the elastic body as described above, it is possible to easily remove burrs on the inner and outer diameters of the sintered body and to position the work by the positioning plate. Therefore, the workability is improved and the size of the mold can be reduced, so that there is an effect of providing a low-cost deburring apparatus.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The manufacturing method of the present invention will be described step by step with reference to FIGS. The sintered body of the present invention will be described as an example of an outer race part used for an automatic transmission of an automobile.

As shown in FIG. 4A, a powder metal material is filled in a mold (not shown) and compressed at a predetermined pressure of about 6 to 7 tons / cm 2 as shown in FIG.
Is molded. Next, the powder compact S1 is left in an atmosphere of 1150 ° C. for 60 minutes to obtain a sintered compact S2.

Next, as shown in FIG. 1, the sintered body S2 is constrained by sizing mold dies D1, D2, a sizing mold upper mandrel 2, and a sizing mold lower upper mandrel 3, and 12 to 13 tons / square centimeter. Recompress at a predetermined pressure.

At this time, as shown in FIG. 1 and FIG. 4 (b), in order to secure the corner chamfered shape of the sintered body S2, between the upper mandrel 2 of the sizing mold and the lower mandrel 3 of the sizing mold, As described in the art, as the upper mandrel 2 and the lower mandrel 3 approach each other, the sintered body S2 is formed in the gap 23 between the upper mandrel 2 and the lower mandrel 3.
Flesh protrudes and a small burr SB is formed on the inner diameter of the sintered body S2.
Occurs.

Next, as shown in FIG. 2, this sized sintered body S2 is placed on a work table 8 and a shaving mold 10
Positioning is performed with the localization plate 7 within 0. A stripper bolt 12 is fixed to the punch holder 11 of the mold apparatus 100 inside the work table 8. The diameter of the stripper bolt 12 is increased stepwise. The stripper bolt 12 includes a first step portion 121 having a large outer diameter, a second step portion 122 having a middle inside diameter, and a third step portion 123 having a small inside diameter. A locking portion 122a is formed.

Further, on the outer periphery of the stripper bolt 12, a movable punch 10 and a punch holder 11 are provided. A contact portion 102 protrudes from an outer periphery of the movable punch 10 so as to contact the sintered body S2. The movable punch 10 has a non-contact portion 10 in the form of a dent that does not contact the sintered body S2.
3 are formed. The outer surface of the contact portion 102 and the outer surface of the non-contact portion are connected by an inclined portion 102a.

The movable punch 10 is provided with a sliding portion 101 having a contact portion 101a which can be locked with a locking portion 122a of the stripper bolt 12, and the movable punch 10 is formed of the stripper bolt 12 and the punch holder 11. By sliding between them, the contact portion 101a of the movable punch 10 is
The movable punch 10 can be locked by contacting the movable punch 22a.

Further, the movable punch 10 and the punch holder 1
Between them, a spring-like elastic body 13 is interposed. Here, the urging force of the elastic body 13 is (the urging force of the elastic body <
(Shear force). Here, the shearing force is a force acting between the sintered body and the movable punch. Alternatively, the urging force of the elastic body is (the urging force of the elastic body <shearing force + μF)
Set to be. Here, the shearing force is a force acting between the sintered body and the movable punch, μ is a coefficient of friction between the movable punch surface and the sintered body surface, and F is the movable punch and the sintered body. Is the force applied perpendicular to the plane between The former setting condition is substantially zero contact between the sintered body S2 and the contact portion 102 of the movable punch 10, and the latter condition causes friction between the sintered body S2 and the contact portion 102 of the movable punch 10. This is the condition when the sintered body S2 is larger (or the contact portion 102 is larger).

The movable punch 10 is made of a sintered body S2
The sintered body S2 can be fixed between the holding plate 9 and the worktable 8 at a position 2 to 3 mm below the upper surface of the inside diameter of the sintered body S2.

Next, as shown in FIG. 2, the operation of the mold apparatus 100 having the above configuration will be described. The punch holder 11, the stripper bolt 12, and the movable punch 10 descend. At this time, the movable punch 10 is in contact with the sintered body S2 by the contact portion 102, and the burrs SB are removed as the movable punch 10 descends.

When the movable punch 10 further descends, the removed burrs SB pass down as they are,
The contact portion 102 of the movable punch 10 comes out of the sintered body S2.

As shown in FIG. 3, when the contact resistance (friction) between the movable punch 10 and the sintered body S2 suddenly disappears, the movable punch 10 is moved downward by the urging force (repulsive force) of the elastic body 13. Is urged and repelled by the impact, the burr SB
Is blown down. At this time, the locking surface 101a of the movable punch 10 comes into contact with the locking surface 122a of the strip bolt 12, and the movable punch 10 is locked.

Thereafter, the work holding plate 9
The movable punch 10 is pulled out from the sintered body S2 while holding down the sintered body S2, and deburring is completed (shaving is completed).
The finished product is shown in FIG.

Since the present invention has the above-described structure, it is possible to remove burrs on the inner and outer diameter portions of the ring-shaped sintered body without affecting accuracy. Further, the workability is improved because the work is merely positioned by the localization plate. Furthermore, the cost can be reduced because the mold can be reduced in size.

The present invention is not limited to the configuration of the above embodiment, and can be applied to removal of a mold burr at any position of the inner diameter portion and the outer diameter portion.

[0037]

As described above, the deburring method of the present invention comprises the steps of filling a powder metal material into a mold and forming the powder compact by compressing the powder metal material at a predetermined pressure. Performing a step of applying heat to the powder compact to form a sintered body, a step of restraining the sintered body between a work table and a work holding plate, and a movable punch and a punch holder. An elastic body is urged between the movable punch and the punch holder, and the movable punch includes a contact portion that contacts the sintered body and a non-contact portion that does not contact the sintered body. A step of moving the punch holder and the movable punch; and, when the contact portion changes from the contact with the sintered body to the non-contact state with the movement of the movable punch, the movable member is moved by the urging force of the elastic body. The punch is extruded and The method of removing burrs of the body is a method of removing burrs, so that the burrs on the inner and outer diameters of the sintered body can be removed without affecting the accuracy of the sintered body, and the work can be removed. Since the positioning is performed only by the positioning plate, the workability is improved, and the size of the mold can be reduced.

Further, the deburring apparatus of the present invention comprises:
A work table and a work holding plate for restraining the sintered body, a stripper bolt fixed to a punch holder,
A movable punch that is pushed out of the punch holder by an elastic body, the movable punch is movable in a compression axis direction of the sintered body, and a contact portion that contacts the sintered body and a non-contact that does not contact the sintered body. A burr, wherein the movable punch has a biasing force set such that the movable punch is pushed out when the contact portion moves to the non-contact portion as the movable punch moves. Since it is a removal device, it is possible to remove burrs on the inner and outer diameters of the sintered body without affecting the accuracy of the sintered body, and since the work is only positioned by the localization plate, workability is improved, and Since the size can be reduced, there is an effect that the cost is low.

[Brief description of the drawings]

FIG. 1 is a sectional view of a mold in a step of performing chamfering and sizing on a sintered body.

FIG. 2 is a sectional view of a mold of the deburring apparatus of the present invention.

FIG. 3 is a sectional view of a mold of the deburring apparatus in the next step of FIG. 2 of the present invention.

FIG. 4 is a schematic view in which a sintered body of the present invention is manufactured.

FIG. 5 is a plan view (right view) and a cross-sectional view taken along line AA of a ring-shaped component used in the ATM of the present invention.

FIG. 6 is a sectional view of a mold of a conventional deburring apparatus in which a punch is chamfered (C-plane shape).

FIG. 7 is a cross-sectional view of a mold showing first to second steps of a conventional punch deburring apparatus.

FIG. 8 is a sectional view of a mold showing a third step of the conventional punch deburring apparatus.

FIG. 9 is a sectional view of a metal mold showing a fourth step of the conventional punch deburring apparatus.

[Explanation of symbols]

 S2: Sintered body 2: Mandrel on sizing mold 3: Mandrel on sizing mold 8: Work table 9: Work holding plate 10: Movable punch 11: Punch holder 12 ... stripper bolt 13 ... elastic body 102 ... contact part 103 ... non-contact part SB ... burr

Claims (4)

[Claims] A step of filling a powder metal material into a mold;
A step of forming a powder compact by compressing the powder metal material at a predetermined pressure; a step of applying heat to the powder compact to form a sintered body; and holding the sintered body on a work table and a work holder. A step of restraining between the plate and a movable punch and a punch holder, an elastic body is urged between the movable punch and the punch holder, and the movable punch contacts the sintered body. A step of moving the punch holder and the movable punch, and a step of moving the movable punch so that the contact section contacts the sintered body. And a step of removing the burr of the sintered body by extruding the movable punch by the urging force of the elastic body when the contact body is brought into a non-contact state. 2. A sintered body, a work table and a work holding plate for restraining the sintered body, a stripper bolt fixed to a punch holder, a movable punch pushed out of the punch holder by an elastic body, The punch is movable in the compression axis direction of the sintered body, and has a contact portion that contacts the sintered body and a non-contact portion that does not contact the sintered body. A deburring apparatus comprising: the elastic body having a biasing force set so that the movable punch is pushed out when the contact portion moves to the non-contact portion. 3. The deburring apparatus according to claim 2, wherein the biasing force of the elastic body set to push the movable punch is such that the biasing force of the elastic body <the shearing force.
Here, the shearing force is a force acting between the sintered body and the movable punch. 4. The deburring apparatus according to claim 2, wherein the biasing force of the elastic body set so that the movable punch is pushed out is such that the biasing force of the elastic body <(shearing force + μF). Here, the shearing force is a force acting between the sintered body and the movable punch, μ is a coefficient of friction between the movable punch surface and the sintered body surface, and F is the movable punch and the sintered body. Force applied perpendicular to the plane between