JP3209919B2 - Machining method and machining apparatus for cutting notch with respect to shaft axis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a technique for processing a notch recess for preventing a rocker arm shaft of an engine from interfering with other members, for example.

[0002]

2. Description of the Related Art Conventionally, for example, a rocker arm shaft of an engine has a pipe shaft having a round cross section to escape to, for example, three places along an axial direction in order to prevent interference with members such as connecting pins. A notch recess is formed. Such a process is usually performed by a broaching machine, for example, broaching three cut recesses simultaneously. In addition, as a technique for drilling a substantially U-shaped or U-shaped workpiece whose part of the cross section is open,
For example, a drilling machine such as Japanese Patent Publication No. Sho 60-21013 is known. In this technique, a die for holding a workpiece is provided in front of a punch, and the die is fitted so as to cover the workpiece. In addition, a plate retainer is provided which moves forward together with the punch, and when the punch is advanced, the workpiece is first pressed by the plate retainer prior to the punch, and then the punch is used to make a hole.

[0003]

However, in the former broaching, since the processing time of one cycle is relatively long, about 24 seconds, the tact times of the preceding and following processes do not match, so that a consistent processing line is formed. There was a problem that it could not be assembled. In addition, the broach requires polishing for approximately 5,000 shots, and when, for example, three broaches are used as one set, there is also a problem that the maintenance of the broaching machine is troublesome. In the latter case, for example, when the cross-sectional shape of the material to be processed is substantially round and processing is performed at a position deviated from the center from a direction orthogonal to the axial direction, the shaft is not sufficiently held. There was a fear. If the holding of the shaft is not sufficient, there is a problem that the shaft rotates around the axis due to the pressing force of the punch during processing.

[0004] Therefore, the processing can be performed while securely holding the shaft having a round cross-section, and by shortening the processing cycle time and performing the processing efficiently, the processing line is formed in a consistent form in accordance with the tact times of the preceding and following processes. A means to obtain it was desired.

[0005]

[MEANS FOR SOLVING THE PROBLEMS]
Invention, given the shaft axis of the cross section round according to claim 1
A processing method for forming a switching <br/> included recess does not reach to the center of the shaft axis in three or more positions at an interval, after positioning fixed by pressing with a predetermined pressure the shaft axis in a predetermined direction,
Direction perpendicular to each of the shaft axis direction and the pressing direction
Approximately three or more punches from both directions sandwiching the shaft axis in
Is moved forward at the same time, it to the shaft axis by each punch
This notch recess is processed by press punching , and at least
Both sides of the punch shaft axis were to so that is advanced in the same direction.

[0006] Then, as described above, at three or more positions on the shaft axis ,
When machining a notch recess that does not reach the center of the shaft axis on the top , if all the punches advance in the same direction ,
The rotational force around the axis to the shaft is applied, be processed substantially advanced simultaneously each punch from opposite sides of the shaft axis, it is possible to offset a rotational force around the axis according to the shaft axis, moreover, the forward direction If the shaft is pressed and fixed from a direction perpendicular to the shaft, the adjustment of the pressing force is relatively easy, so that the rotation of the shaft can be reliably prevented. And, more 3箇 to punching expressions in three or more of the punch
By forming more than one cut recess, the processing time can be shortened and a consistent processing line can be formed.

In the second aspect, the shaft shaft is pressed and fixed by pressing the shaft shaft over substantially the entire length. By pressing in this manner, the positioning and fixing are reliably performed. Further, when three or more cut-out recesses are formed at one edge of the shaft by a punch, the shaft tends to bend so that the cut-out recess-forming side is the outer surface. Therefore, if the shaft shaft is pressed over substantially the entire length in the direction in which the shaft shaft is going to bend by forming the cut recess, the bending after processing is prevented.

[0008] The invention according to claim 3 is that the center of the shaft is provided at three or more places at predetermined intervals on the shaft having a substantially round cross section.
Processing apparatus for forming a cut recess does not reach at met
A pedestal on which the shaft is mounted, a pressing pad for pressing the shaft with a predetermined pressure toward the pedestal, and a pressing pad disposed on both sides of the shaft in a plane orthogonal to the pressing direction with respect to the shaft. Three or more punches, and a press mechanism for advancing each punch substantially simultaneously toward the shaft axis, wherein at least the punches on both sides of the shaft axis are in the same direction.
To move forward . Then, the shaft shaft mounted on the receiving table is pressed and held by the pressing pad, and three or more punches arranged on both sides of the shaft shaft are advanced almost simultaneously by the press mechanism to process each cut recess.

According to a fourth aspect of the present invention, the shape of the tip of the punch is
The shaft is curved so that the amount of forward projection gradually decreases from a portion corresponding to the center of the shaft to a portion corresponding to the edge of the shaft. With such a shape, double cutting is prevented when the end is punched from a direction perpendicular to the shaft axis.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a longitudinal sectional view of the processing apparatus, FIG. 2 is a plan view of a lower die, FIG. 3 is a sectional view taken along line AA of FIG. 2, FIG. 4 is an explanatory view of a rocker arm shaft, FIG.
Is an explanatory view showing an example of processing four cut recesses, and FIG. 6 is an assembly view of a rocker arm shaft.

The method for processing a notch recess according to the present invention is applied when forming notch recesses c at three locations along the axial direction of a pipe-shaped rocker arm shaft S as shown in FIG. The recesses c,... Are formed for escape to avoid interference with the assembly pins P,... In the assembled state of the rocker arm shaft S as shown in FIG.

A processing apparatus 1 for performing such processing
As shown in FIGS. 1 and 2, an upper die 3 that can move up and down with respect to the lower die 2 is provided. In the center of the upper part of the lower die 2, dies 4,. Installed. On the left and right sides of the lower die 2 with the dies 4,..., Slide guides 5 are attached at two places on one side and one place on the other side, for a total of three places. , Are provided with respective slide holders 6, slidable in the left-right direction in the figure. The punches 7,... Are mounted on the front side of the slide holders 6,..., And a cam surface 6a is formed on the rear upper surface of the slide holders 6,.

A pressing pad 10 urged downward by a pressing spring 8 is provided at a lower central portion of the pressure receiving plate 3a of the upper die 3 shown in FIG. Are vertically pressed and held. For this reason, holding grooves 10 a and 4 a having a semicircular cross section to be fitted to the half body of the shaft S are formed on the lower surface of the pressing pad 10 and the upper surface of the die 4.

A cam upper 11 having a cam surface 11a on its lower surface is attached to both sides of the pressure receiving plate 3a.
When the cam upper 11 is lowered, the cam surface 11a presses the cam surface 6a of the slide holder 6 to advance the slide holder 6 toward the die 4.

As shown in FIG. 3, the die 4 has a punch hole 4b through which the tip of the punch 7 can be inserted.
And a pair of left and right bag-shaped spring holes 4c, 4c sandwiching the punch hole 4b, and the springs 12, 12 are housed in the bag-shaped spring holes 4c, 4c, respectively. The other ends of the springs 12, 12 are in contact with the front surface of the slide holder 6, and when the slide holder 6 advances toward the die 4, the springs 12, 12 contract and push the slide holder 6 back. It is urged in the direction.

The punch hole 4b is formed in a vertically long circular shape in accordance with the cross-sectional shape of the punch 7 described later, and intersects at right angles with the groove direction of the holding groove 4a on the upper surface of the die 4. A part of the upper end of the punch hole 4b is opened to the inside of the holding groove 4a.

As shown in FIG. 1, the punch 7 is detachably mounted on the front surface of the slide holder 6, and has a vertically long circular cross section. The clearance between the punch 7 and the punch hole 4b is set to 0.1 mm or less in order to suppress the generation of burrs during processing.
Further, as shown in FIG. 1, the front surface of the punch 7 is curved so that the upper end protrudes forward and the forward protruding amount gradually decreases toward the lower end. With such a shape, double cutting does not occur when the lower end portion of the shaft S is punched. Incidentally, B1 to B4 in FIG. 2 are reinforcing blocks.

In the processing apparatus 1 as described above, the shaft S is placed in the holding groove 4a of the die 4, and the upper die 3 is placed from above.
When the pressure receiving plate 3a is lowered, the holding groove 10a of the pressing pad 10 first comes into contact with the upper surface of the shaft S, and presses the shaft S downward. The pressing force of the pressing spring 9 is, for example, about 9 tons, and the three pressing pads 1
A load of about 3 tons is applied to each of 0,.

When the load of about 3 tons by the pressing pad 10 is, for example, too light, the upper die 3 is raised when the cuts c are formed at the lower end of the shaft S. Both ends of the shaft S are 0.2-0.3
The pressure is sufficient to prevent such a problem of the warping because it is curved so as to warp upward by about mm.

At substantially the same time when the shaft S is pressed and held in the vertical direction, the cam surfaces 11a of the cam uppers 11 on both sides come into contact with the cam surfaces 6a of the slide holder 6, and the slide holder 6 is turned toward the die 4. Let go forward.
For this reason, the punch 7 moves forward in the punch hole 4b of the die 4, and three cut recesses c,... Are formed almost simultaneously at the lower end of the shaft S.

Incidentally, since the notches c ,... Do not reach the center of the shaft axis, when the punch 7 comes into contact with the shaft S, the shaft S receives a rotational force around the axis. Therefore, such a rotational force can be suppressed if the punches 7,... Are brought into contact from both sides almost simultaneously, but in the embodiment, two of the punches 7,. The punches 7, 7 are brought into contact with the shaft S almost at the same time, and then the remaining one punch 7 is brought into contact with the timing slightly later. With such timing, the rotational force applied to the shaft S around the axis can be further suppressed.

Further, the punch hole 4b of the die 4 and the punch 7
Since the clearance between them is set to 0.1 mm or less, burrs at the time of processing can be reduced, for example, the durability of the subsequent endless grinding wheel can be improved, and the finish quality can be improved. . Further, double cutting is prevented by the curved shape of the tip of the punch 7.

When the upper die 3 is lifted after the processing, the slide holders 6,... Are pushed back by the springs 12, and the punches 7,. The processing time in such a processing method is approximately 7 seconds.

FIG. 5 shows four notches c,
FIG. 9 is a plan view showing an example of a procedure for advancing the punches 7 when processing..., For example, two punches at both sides and two punches at an intermediate portion are arranged with a shaft S interposed therebetween, and these are simultaneously advanced. Process. Although not shown, it goes without saying that the present invention can be applied to the processing of five or more notch recesses c,. Further, in the embodiment, the shaft S is a pipe, but it is needless to say that a round bar or an elliptical bar may be used.

[0025]

As described above, according to the present invention, the processing
After the shaft is positioned and fixed as in the method and the processing apparatus according to claim 3, three or more from both directions sandwiching the shaft are provided.
Substantially advanced simultaneously punches above sheet by the punch
If the notch recess that does not reach the center of the shaft is machined by press punching, it can be machined in a stable state without rotating the shaft, and the machining time can be shortened to achieve a consistent machining line form. I can do it. Claims
If the entire length of the shaft is pressed and fixed at a predetermined pressure as in 2 , it is possible to prevent the shaft from warping during machining. And request the tip shape of the punch
According to item 4 , when the end portion is punched from a direction perpendicular to the shaft axis, double cutting is prevented, and the durability of the punch can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the present processing apparatus.

FIG. 2 is a plan view of a lower mold.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an explanatory view of a rocker arm shaft.

FIG. 5 is an example of a method for forming four notched concave portions;

FIG. 6 is an assembly diagram of a rocker arm shaft.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing apparatus, 2 ... Lower mold, 3 ... Upper mold, 4 ... Dies, 7 ...
Punch, 10: pressing pad, S: rocker am shaft, c: cut notch.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-309738 (JP, A) JP-A-51-89 (JP, A) JP-A-52-57583 (JP, A) JP-A-8-58 10869 (JP, A) JP-A-7-314060 (JP, A) JP-A 51-91883 (JP, U) JP-A 59-106636 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21D 28/24 B21D 28/28 B21D 28/34 B21D 43/00 B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00

Claims (4)

(57) [Claims] 1. A shaft shaft having a substantially round cross section is provided at predetermined intervals.
A processing method for forming notch recesses that do not reach the center of the shaft at three or more locations , wherein the shaft is pressed and fixed at a predetermined pressure in a predetermined direction, and then each of the shaft axis and the pressing direction is fixed. orthogonal substantially to advance simultaneously three or more punches from both directions sandwiching the shaft axis in the direction, each of the cut recesses in the shaft axis machining the press punching formula by each punch, at least Shah
Method for processing a cut recess relative to the shaft axis on both sides of the punch of shift shaft, characterized in Rukoto is advanced in the same direction. 2. A cutting device for a shaft according to claim 1.
In the method of processing the recess, the pressing of the shaft is fixed.
Is determined by pressing the shaft over almost the entire length.
We processing method of cut recess relative to the shaft axis, characterized in Rukoto. 3. A method according to claim 1, wherein the shaft has a substantially circular cross section at a predetermined interval.
Notch recess that does not reach the center of the shaft at more than three places
A processing apparatus for forming
A receiving table to be placed, and this shaft axis is directed toward the receiving table.
A pressing pad that presses at a predetermined pressure and a pressing
Located in the plane perpendicular to the pressure direction and on both sides of the shaft axis
Three or more punches and each punch
With a press mechanism that moves forward almost simultaneously.
Both sides of the punch also shaft axis machining instrumentation of cut recess relative to the shaft axis, wherein the this <br/> advancing in the same direction
Place . 4. A cutting device for a shaft according to claim 3, wherein
In the processing device for the concave recess, the tip shape of the punch
Is the shaft axis from the part corresponding to the center side of the shaft axis.
The amount of forward protrusion toward the part corresponding to the edge of
An apparatus for processing a notch concave portion with respect to a shaft axis, wherein the concave portion is curved so as to be curved .