JP3715658B2 - Method for forming recess of cylindrical body - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a forming method for forming, for example, a concave portion used as a detent groove in a cylinder used as a shift rod of a vehicle transmission.
[0002]
[Prior art]
In general, for example, a shift rod of a vehicle transmission partially cuts the outer peripheral surface of a round bar to form a recess as a detent groove. However, such a shift rod is heavy.
[0003]
In view of this, the inventor of the present application uses a metal hollow member in order to reduce the weight of the shift rod, and in order to form the concave portion in the hollow member, Then, the punch member is inserted into the insertion hole formed in the upper mold, the outer peripheral wall portion of the hollow member is pressed by the punch member, and a desired recess is formed in the outer peripheral wall portion of the hollow member. I thought about forming it.
[0004]
[Problems to be solved by the invention]
By the way, in the above forming method, during the pressing operation by the punch member, the pressing force of the punch member is directly transmitted not only to the recessed portion forming portion but also to the peripheral portion thereof, and the peripheral force causes the peripheral edge. There is a problem that the part is deformed radially outward and in a direction perpendicular to the direction in which the pressure is applied.
[0005]
The present invention has been developed in view of the above circumstances, and an object of the present invention is to suppress deformation of the peripheral edge adjacent to the recess forming portion when forming the recess in the cylindrical body by press working. The object of the present invention is to provide a method for forming a concave portion of a cylinder.
[0006]
[Means for Solving the Problems]
Accordingly, the present invention is a method of forming a plurality of recesses in a cylindrical body made of a metal material, and is formed of a ductile material that is softer than the material hardness of the cylindrical body in the middle of the longitudinal direction of the cylindrical body. After the filling rod is filled, the filling rod is plastically deformed by pressing the middle to form a plurality of recesses separated in the longitudinal direction of the cylinder, and then the filling rod is left in the filling position. It is characterized by.
[0007]
[Action]
According to the present invention, at the time of pressing the recessed portion forming portion in the cylindrical body, the pressing force accompanying the pressing operation is transmitted to the filling rod, and the portion of the filling rod facing the recessed portion is recessed, and at the same time, the filling rod is plastic. Since the pressing force of the punch member is absorbed by the filling rod due to deformation, the pressing force of the punch member transmitted to the peripheral part of the recess forming part in the hollow member is weakened, and the peripheral part is radially outward. The deformation to is suppressed.
[0008]
【Example】
In the embodiment shown in the figure, a detent mechanism that restricts a moving stroke of a shift rod to a cylindrical body (hereinafter referred to as a hollow member) 1 made of a metal material used as a 1- and 2-speed shift rod of a vehicle transmission. An example in which three recesses 2a, 2b and 2c used as detent grooves are formed by a press machine will be described.
[0009]
As shown schematically in FIG. 3, the press working machine includes a mold 3 composed of an upper mold 3a and a lower mold 3b each having a fitting recess into which the hollow member 1 is fitted. The punch member 4 is inserted into a through-hole 31 formed in the upper die 3a and presses the hollow member 1, and the recesses 2a, 2b, and 2c are pressed on the lower surface of the punch member 4. Three projections 4a, 4b, and 4c for molding are provided.
[0010]
The hollow member 1 shown in the figure is a cylinder made of structural carbon steel (JIS standard S48C-D) having a Vickers hardness of 180 degrees, and the hollow member 1 has a cross-sectional curve on the outer circumferential wall on one side in the longitudinal direction. The three concave portions 2a, 2b, and 2c are continuously formed, and when the concave portions 2a, 2b, and 2c are formed, the concave portions in the hollow member 1 are formed as shown in FIG. A filling rod (hereinafter referred to as an aluminum alloy round rod having a Vickers hardness of 70 to 80 degrees), which is softer than the material hardness of the hollow member 1, is formed on a portion facing the formation portion of 2a, 2b and 2c. (Referred to as filling member) 5 is filled.
[0011]
And as shown in FIG. 3, after inserting the said hollow member 1 which equipped the filling member 5 as mentioned above between the fitting recesses of the upper mold | type 3a and the lower mold | type 3c which comprise the said mold 3, By applying a predetermined pressing force to the punch member 4 set in the through hole 31 of the upper mold 3a, the recess forming portion in the hollow member 1 is pressed through the punch member 4.
[0012]
As a result, predetermined recesses 2a, 2b, and 2c are press-molded at the recess-forming portion of the hollow member 1 by press working with the punch member 4, but the punch member 4 is pressed along with the press molding. The pressure is transmitted to the filling member 5 through the outer peripheral wall portion in which the concave portions 2a, 2b, and 2c are formed in the hollow member 1, and the pressing force is also received by the filling member 5. The filling member 5 is plastically deformed in the axial direction at the same time as the portions facing the recesses 2a, 2b, and 2c are recessed, and the pressing force of the punch member 4 is absorbed by the filling member 5. Accordingly, the pressing force of the punch member 4 transmitted to the peripheral portion of the hollow forming portion in the hollow member 1 is weakened, and as a result, deformation of the peripheral portion in the radially outward direction is suppressed.
[0013]
In the above embodiment, the hollow member 1 is filled with the filling member 5 made of a round bar. However, as schematically shown in FIG. 6, the filling member 5 has a depth greater than the groove depth of the recesses 2a, 2b, and 2c. The recesses 5a, 5b and 5c which are shallow and slightly wider than the groove widths of the recesses 2a, 2b and 2c may be formed in advance, and thus the recesses 5a, 5b and 5c are provided in advance. When the member 5 is used, the thickness of the outer peripheral wall portion of the hollow member 1 where the recesses 2a, 2b, and 2c are formed is suppressed from being thinned depending on the portion due to the press work by the punch member 4. I can do it.
[0014]
That is, when the recesses 5a, 5b, and 5c are not formed in the filling member 5, between the recesses 2a, 2b, and 2c that are press-formed on the hollow member 1 in accordance with the press work by the punch member 4. Since the sandwiched filling member 5 is difficult to be ductile with the formation of the recesses 2a, 2b, and 2c, the outer peripheral wall portion where the recesses 2a, 2b, and 2c are formed is pushed by the filling member 5. It is also possible that some will become thin. However, by forming the recesses 5a, 5b, and 5c in advance in the filling member 5 as described above, a space allowing the ductility of the filling member 5 is ensured when the punch member 4 is pressed. Therefore, the thickness of the outer peripheral wall portion where the concave portions 2a, 2b and 2c are formed in the hollow member 1 can be made substantially uniform.
[0015]
In the above embodiment, the hollow member 1 is a cylindrical body made of structural carbon steel (JIS standard S48C-D) having a Vickers hardness of 180 degrees, but is not limited thereto, and is made of, for example, stainless steel. A cylindrical body may be used.
[0016]
Moreover, although the hollow member 1 was made into the cylindrical shape in the above Example, a rectangular tube shape may be sufficient.
[0017]
In the above embodiment, the filler 5 made of an aluminum alloy material having a Vickers hardness of 70 to 80 degrees is used. However, the present invention is not limited to this. For example, the filler 5 is made of copper, zinc, synthetic resin or reinforced wood. A material may be used.
[0018]
In the above embodiment, the hollow member used as the shift rod of the vehicle transmission has been described as an example in which the concave portion used as the detent groove is formed. However, the present invention is not limited to this. The present invention can be widely applied in the case where the concave portion is formed in the wall portion.
[0019]
In FIG. 3, reference numeral 6 denotes a shift head that is fixed to one end in the length direction of the hollow member 1 by welding, and the shift head 6 has a fitting groove 61 in which a shift lever is selectively fitted. Is provided.
[0020]
【The invention's effect】
As described above, according to the present invention, the pressing force accompanying the pressing operation is transmitted to the filling rod at the time of pressing the recessed portion forming portion in the cylindrical body, and the pressing force is absorbed by the filling rod by plastic deformation of the filling rod. Therefore, the pressing force transmitted to the peripheral portion of the concave portion forming portion in the cylindrical body is weakened, and the peripheral portion can be prevented from being deformed radially outward.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a cylinder body with a filling member partially omitted.
FIG. 2 is an enlarged sectional view taken along line XX in FIG.
FIG. 3 is a perspective view showing a state in which a cylinder body with a filling member is pressed.
FIG. 4 is a partially cutaway side view of a pressed cylinder.
5 is an enlarged sectional view taken along line YY in FIG.
FIG. 6 is a cross-sectional view of a main part showing another embodiment of a cylindrical body in which a filling member is housed.
[Explanation of symbols]
1 Cylinder 2a, 2b, 2c Recess 5 Filling member (filling rod)

Claims (1)

A recess forming method for forming a plurality of recesses in a cylindrical body made of a metal material,
After filling a filling rod made of a ductile material softer than the material hardness of the cylinder in the middle of the longitudinal direction of the cylinder, the filling rod is plastically deformed by pressing the middle to form the cylinder A method of forming a concave portion of a cylindrical body, comprising: forming a plurality of concave portions spaced apart in a longitudinal direction, and thereafter leaving the filling rod at a filling position.

Images