US3413880A

US3413880A - Method and apparatus for producing holes in sidewalls of members having channel-like cross sections

Info

Publication number: US3413880A
Application number: US437031A
Authority: US
Inventors: Joesph E Foist
Original assignee: Toledo Stamping and Manufacturing Co
Current assignee: Toledo Stamping and Manufacturing Co
Priority date: 1965-03-04
Filing date: 1965-03-04
Publication date: 1968-12-03
Anticipated expiration: 1985-12-03

Description

Dec. 3, 1968 J. E. FOIST 3,413,830

METHOD AND APPARATUS FOR PRODUCING HOLES IN SIDEWALLS OF MEMBERS HAVING CHANNEL-LIKE CROSS SECTIONS Filed March 4, 1965 2 Sheets-Sheet l j Kg 7 6 lb INVENTOR: 26 72 M 6 JUBBPHE. F0157".

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Dec. 3, 1968 J. E. FOIST 3,4fl3,880

METHOD AND APPARATUS FOR PRODUCING HOLES IN SIDEWALLS OF MEMBERS HAVING CHANNEL-LIKE CROSS SECTIONS Filed March 4, 1965 2 Sheets-Sheet P,

INVENTOR. JUSEPH E. F015 '1.

ATTys United States Patent METHOD AND APPARATUS FOR PRODUCING HOLES IN SIDEWALLS OF MEMBERS HAV- ING CHANNEL-LIKE CROSS SECTIONS Joesph E. Foist, Toledo, Ohio, assignor to Toledo Stamping & Manufacturing Company, Toledo, Ohio, a corporation of Ohio Filed Mar. 4, 1965, Ser. No. 437,031 6 Claims. (Cl. 83-54) This invention relates to a method and apparatus for producing openings in walls of workpieces or bodies adjacent surfaces extending transversely of the walls, and more particularly to a method and apparatus for piercing holes in sidewalls of rocker arms.

The instant invention primarily is directed to the piercing of holes in stamped rocker arms having generally channel-shaped transverse cross sections. Rocker arms of this type can be made without employing separate bushings which must subsequently be assembled with the rocker arms, resulting in extra operations and relatively high cost. The rocker arm of the type under consideration is discussed more fully in US. Patent Re. 24,941. When in operating position, the rocker arm is located with the open portion extending upwardly so that the rocker arm, in effect, forms a container for lubricating oil supplied through a hollow supporting shaft for the rocker arm. In this type of rocker arm, the openings in the sidewalls through which the supporting shaft extends must be close to or substantially tangential with the bottom or transverse wall of the rocker arm since a portion of this wall forms a bearing surface for the shaft. Heretofore, it had been necessary to form these holes by using a diagonallydisposed punch extending through the open portion of the rocker arm and toward the junction of the sidewall and bottom wall, as shown in more detail in US. Patent 2,917,033. The openings in the sidewalls of the rocker arms produced with this technique, however, were less than satisfactory in several respects. For one thing, the holes were not circular but tended to assume an oval shape so that the rocker arm would not fit closely with the supporting shaft. This resulted in excessive leakage of the oil held by the rocker arm, and also tended to cause excessive noise or clatter, particularly when an engine using the rocker arms was first started.

The present invention provides a novel method and apparatus for producing holes in walls of bodies closely adjacent or tangential to a transverse surface thereof. The invention is particularly useful for producing Openings in rocker arms of the type discussed above, but need not necessarily be limited to such.

In accordance with the invention, a punch of a shape corresponding to the desired shape of the opening to be produced in the wall of the body is rigidly held at the end of a supporting arm which is affixed to a supporting and driving member effective to drive the punch through a fixed path parallel to the axis thereof. With this arrangement, the punch is capable of being inserted into the body or rocker arm and pierce the hole in the sidewall from the inside out. The outer surface of the sidewall of the body is backed up by a suitable back-up die having an opening to receive the punch, which opening is similar to that to be formed in the sidewall of the workpiece or body. Additionally, a supporting block having an end engageable with the outer surface of the transverse portion of the body or rocker arm is provided to prevent the body from moving away from the punch as the punch moves toward the sidewall and the backup die. This is particularly important since a fillet is commonly formed between the transverse surface and the sidewall and this surface otherwise tends to cam or 3,413,880 Patented Dec. 3, 1968 force the body away from the punch as the punch moves toward the sidewall and engages the fillet.

It is, therefore, a principal object of the invention to provide an improved method and apparatus for producing openings in the walls of bodies adjacent transverse surfaces thereof.

Another object of the invention is to provide an improved method and apparatus for producing supporting shaft openings in sidewalls of channel-like rocker arms, tangential to the bottom wall thereof.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawing, in which:

FIG. 1 is a view in perspective of a body or rocker arm having holes pierced therein in accordance with the invention;

FIG. 2 is a view in transverse cross section taken along the line 22 of FIG. 1, and further showing a rocker arm supporting shaft in dotted lines;

FIG. 3 is a view in vertical cross section of apparatus for producing openings in sidewalls of the rocker arm of FIGS. 1 and 2;

FIG. 4 is a view similar to FIG. 3 but with the die units closed and with a hole being pierced;

FIG. 5 is a plan view of the lower die unit, with the upper die unit removed; and

FIG. 6 is a fragmentary view of a portion of the lower die unit of FIG. 5 showing certain parts of the apparatus in a retracted position.

Referring more particularly to FIGS. 1 and 2, a body or rocker arm 10 is shown after holes are produced therein by means of the method and apparatus according to the invention. The rocker arm 10 includes a bottom wall or web 12 forming a transverse surface to

sidewalls

14 and 16. Part of the bottom wall 12 is arcuate in longitudinal cross section and has a radius substantially similar to that of a rocker arm supporting shaft 18. The bottom wall 12, being closely adjacent the shaft 18, provides an effective bearing surface for the rocker arm which is pushed upwardly against the shaft 18 by the push rod and valve stem (not shown) with which it is engaged when assembled in an engine. The rocker arm 10 has

openings

20 and 22 in the sidewalls thereof which are closely adjacent or tangential to the bottom wall 12 so that the lower edges of the openings substantially form continuations of the inner surface of the bottom wall 12 lying transversely to the

sidewalls

14 and 16. As such, these edges of the

openings

20 and 22 constitute eX- tended bearing surfaces for the rocker arm. The

openings

20 and 22 are truly circular and lit closely with the rocker arm supporting shaft 18. Hence, there is no problem of noise or chatter particularly when the engine is first started, and the close fit also enables the rocker arm to retain oil therein much more effectively than heretofore possible with rocker arms of this general type.

Referring more particularly to FIGS. 3-5, a die set indicated at 24 includes a lower die unit 26 and an upper die unit 28. While the die set 24 is shown as having only one station, two stations can be used to advantage to form the openings in opposite sidewalls of two of the rocker arms at the same time.

The lower die unit 26 includes a supporting table or base 30 upon which are located a punch assembly 32, a back-up die 34, and a supporting block 36. The punch assembly 32 includes a clamping block 38 having a recess 40 in which is received a shank 42 of a punch 44 having a horizontal cross-sectional shape equal to that of the opening 20 or 22.

The punch 44 can be equipped with a replaceable hardened steel insert, if desired, as is known in the art. The punch 44 is moved in a direction perpendicular to a face 46 thereof to engage the sidewall 14 and pierce the hole 20 therein. The punch shank 42 includes a contoured outer end 48 which fits with the inner surface of the bottom wall 12 and helps maintain the body 10 in position and retains the shape thereof during the piercing operation. The clamping block 38 moves in the described manner, being controlled by tracks or ways 50 and 52 (FIG. having raised portions 54 and 56 cooperating with grooves 57 and 58 in the block 38. The ways 50 and 52 are supported and spaced apart by a rear wall 60.

The maximum downward movement of the punch 44 can be determined by the limits of downward movement of the upper die unit 28 or by contact of the clamping block 38 and the upper surface of the table 30. The limit of upward movement of the punch 44, on the other hand, is determined by bolts or stop pins 62 affixed to side portions of the block 38 and extending through passages 64 in the table 30. Heads 66 of the bolts 62 are located in lower recesses 68 with the heads 66 abutting the upper ends of the recesses 68 to determine the upper limit of movement. The block 38 also has four springs 70 at the corners thereof, positioned in recesses 72 of the table 30. The springs urge the punch 44 and the block 38 upwardly, moving the blocks in this manner until the bolt heads 66 contact the ends of the recesses 68 when the upper die unit 28 is raised.

The back-up die 34 has a shallow recess 73 which is contoured to receive a portion of the rocker arm 10, as shown in FIG. 6. The recess 73 helps position the rocker arm and also helps support the arm at the junction of the sidewall 14 and the bottom wall 12. The die 34 also includes a passage 74 having a cross-sectional shape and size similar to those of the shaft opening of the arm 10. The passage 74 receives a slug 75 from the rocker arm opening 20 with the slug 75 being disposed of through a suitable opening 76 in the base 30.

The assembly 3 6 includes a cam-operated slide 78 guided between ways 80 and 82 for reciprocable movement toward and away from the punch 44. A supporting block 84 is mounted on the slide 78 and includes a contoured end portion 86 which engages and backs up an arcuate portion of the wall 12 during the piercing operation. The supporting block 84 is important to the operation in order to assure that the opening 20 in the sidewall 14 will be tangential to the inner surface of the wall 12. Without the supporting block 84, the edge of the punch 44 would engage the small fillet between the bottom wall 12 and the sidewall 14 immediately prior to piercing the sidewall and push the bottom wall of the rocker arm away from the punch. This would cause the hole to be pierced farther from the inner surface of the wall 12 than would otherwise occur with the supporting block 84.

The slide 78 and the supporting block 84 are urged away from the punch 44 by a coil spring 88 maintained in compression between a spring bar 90 mounted on the table and nuts 92 afiixed to the end of a threaded rod 94- extending through a passage 96 in the bar 90 and threadedly engaged in an end of the slide 78. When the slide 78 is not acted upon by other forces, it is maintained in a retracted position away from the die 34 by virtue of the spring 88.

Referring now more particularly to the upper die unit 28, a mounting plate 98 is supported parallelly to the base 30 and is driven in a vertical path by suitable means (not shown). The mounting plate 98 is guided by a pair of guide posts 100 affixed to the base 30 at one side of the die components. A drive block 102 is affixed to the mounting plate 98 near one end thereof and is posi tioned to engage the clamping plate 38 and the shank 42 when the plate is driven downwardly. The block 102 moves the punch 44 downwardly and causes it to pierce the hole 20, as shown in FIG. 4. When the block 102 is raised, as shown in FIG. 3, the punch 44 is moved upwardly to a position in which the body 10 can be slipped off the punch.

The mounting plate 98 also carries a depending cam member 104 having a pair of cam fingers 106 positioned on opposite sides of the rod 94. The fingers .106 extend into slots 107 in the base 30.

When the plate and the fingers 106 move downwardly, they engage a slanted rear surface 108 of the back-up block 84 and force the block 84 and the slide 78 forwardly against the rocker arm 10. The block 84 is then held locked in the forward position as the cam member 104 moves downwardly with the fingers 106 below the rearward end of the block 84, as shown in FIG. 4. The cam member 104 is arranged to force the block 84 forwardly before the punch 44 begins the piercing operation to assure that the rocker arm 10 will remain in position and not be forced away from the punch as it engages the fillet.

The mounting plate 98 includes a third component, a hold down block 109 supported by a bolt 110, a head 112 of which is located in a recess 114 on top of the mounting plate 98. A spring 116 is located between the block 109 and the mounting plate 98 and urges the block downwardly. The hold down block 109 engages the upper sidewall 16 of the arm 10 as the mounting plate 98 moves downwardly before the other components come into contact to assure that the rocker arm 10 will be positioned properly on the die block 34 before the piercing operation begins.

While a preferred embodiment of the invention has been described in the preceding specification, it is to be understood that the invention is capable of numerous modifications without departing from the scope of the invention as defined in the accompanying claims.

I claim:

1. Apparatus for producing an opening in a sidewall of a rocker arm which has a U-shaped transverse cross section with the opening adapted to receive a rocker arm supporting shaft adjacent a bottom wall of the rocker arm, said bottom wall being arcuate in a direction longitudinally of the rocker arm and having a radius substantially equal to a radius of :a substantial edge portion of said opening adjacent said bottom wall, with the centers of radius being superimposed, said apparatus comprising a supporting and driving member, a connecting arm extending outwardly from said supporting and driving member and held thereby, a punch having a circular cross-sectional shape of a size similar to the opening to be produced, said punch being functionally integral with the outer end of said connecting arm and movable with said connecting arm in :a direction substantially perpendicular to a face of said punch and to the wall, the face of said punch also being substantially parallel to the longitudinal extent of said connecting arm, the total height of said connecting arm and said punch being less than the distance between the sidewalls of said rocker arm to enable said punch and said connecting arm to fit therein, a back-up die having an opening aligned with said punch for receiving same, said back-up die having a recessed surface facing said punch which is contoured to the shape of an edge portion of the sidewall of said rocker arm through which the opening is to be made, a supporting block having an end engageable with the bottom wall of said rocker arm to prevent said bottom wall from moving away from said punch when said punch is moved toward said back-up die, and means for moving said supporting block toward and away from the rocker arm.

2. Apparatus for producing an opening in a sidewall of a rocker arm which has a U-shaped cross section with the opening adapted to receive a rocker arm supporting shaft adjacent a bottom wall of the rocker arm, said bottom wall being arcuate in a direction longitudinally of the rocker arm with a substantial portion of the bottom wall and a substantial edge portion of said opening having equal radii, with the centers of radius being superimposed, said apparatus comprising a supporting and driving member, a connecting arm extending outwardly from said supporting and driving member and held thereby, a punch having a cross-sectional shape similar to the opening to be produced, said punch being functionally integral with the outer end of said connecting arm and movable with said connecting arm in a direction substantially perpendicular to a face of said punch, the total height of said connecting arm and said punch being less than the distance between the sidewalls of said rocker arm to enable said punch and said connecting arm to fit therein, a back-up die having an opening aligned with said punch for receiving same, said back-up die having a surface facing said punch which is contoured to the shape of the sidewall of said rocker arm through which the opening is to be made, a supporting block engageable with the bottom wall of said rocker arm to prevent said bottom wall from moving away from said punch when said punch is moved toward said back-up die, and means for moving said supporting block toward and away from the rocker arm and for rigidly supporting said block against said wall.

3. Apparatus for producing an opening in a sidewall of a rocker arm which has a U-shaped cross section with the opening adapted to receive a rocker arm supporting shaft adjacent a bottom wall of the rocker arm, said bottom wall being arcuate in a direction longitudinally of the rocker arm and having a radius substantially equal to a radius of a substantial edge portion of said opening adjacent said bottom wall, with the centers of radius being superimposed, said apparatus comprising a supporting and driving member, a connecting arm extending outwardly from said supporting and driving member and held thereby, a punch having a circular cross-sectional shape of a size similar to the opening to be produced, said punch being functionally integral with the outer end of said connecting arm and movable with said connecting arm in a direction substantially perpendicular to a face of said punch and to the wall, the face of said punch also being substantially parallel to the longitudinal extent of said connecting arm, the total height of said connecting arm and said punch being less than the distance between the sidewall of said rocker arm to enable said punch and said connecting arm to fit therein closely adjacent the bottom wall, and a back-up die having an opening aligned with said punch for receiving same, said backup die also having a recessed surface which is contoured to the shape of an arcuate edge portion of the sidewall of said rocker arm where said edge portion meets said bottom wall and through which the opening is to be made to aid in locating the rocker arm with respect to said punch.

4. A method for producing a substantially circular opening in a sidewall of a rocker arm with a substantial edge portion of said opening being substantially coextensive with an arcuate bottom wall thereof extending transversely of the sidewall, said method comprising supporting a punch within said rocker arm and substantially tangentially to the bottom wall of the rocker arm, backing up said sidewall around a portion through which said opening is to be produced, moving said punch toward and through said sidewall, and firmly supporting a substantial portion of said bottom wall of said rocker arm adjacent which the opening is made to prevent movement of said bottom wall away from said punch as said punch approaches said sidewall adjacent said bottom wall. 1

5. Apparatus for producing an opening in a sidewall of a rocker arm which has a generally U-shaped transverse cross section, with the opening adapted to receive a rocker arm supporting shaft adjacent a bottom wall of the rocker arm, said apparatus comprising a supporting member, an arm extending outwardly therefrom, a punch having a cross-sectional shape similar to that desired for said opening, said punch being functionally integral with the outer end of said arm and movable with said arm in a direction transversely of a face of said punch, the punch face being substantially parallel to the longitudinal extent of said arm, at least a substantial part of the outer end of said arm having the same contour as part of the inner surface of the bottom wall of the rocker arm, a back-up die having an opening aligned with said punch and having a surface facing said punch which supports a portion of the outer surface of the sidewall of the rocker arm while the opening is being made therein, supporting means engageable with the outer surface of the bottom wall of the rocker arm to prevent the bottom wall of the rocker arm from moving away from said punch when said punch is moved toward said backup die, and means for moving said supporting means toward and away from the bottom wall of the rocker arm.

6. Apparatus for producing an opening in a sidewall of a rocker arm which has a generally U-shaped, transverse cross section, with the opening adapted to receive a rocker arm supporting shaft adjacent a bottom wall of the rocker arm, said bottom wall being arcuate in a direction longitudinal of the rocker arm and having a radius substantially equal to a radius of a substantial edge portion of said opening, with the centers of the radii being superimposed, said apparatus comprising a supporting and driving member, an arm extending outwardly from said supporting and driving member and held thereby, a punch having a cross-sectional shape similar to that desired for said opening, said punch being functionally integral with the outer end of said arm and movable with said arm in a direction substantially perpendicular to a face of said punch, the punch face being substantially parallel to the longitudinal extent of said arm, a back-up die having an opening aligned with said punch, said back-up die having a surface facing said punch which supports a portion of the outer surface of the sidewall of the rocker arm while the opening is being made therein, supporting means engageable with the outer surface of the bottom wall of the rocker arm to prevent the bottom wall of the rocker arm from moving away from said punch when said punch is moved toward said back-up die, and means for moving said supporting means toward and away from the rocker arm.

References Cited UNITED STATES PATENTS 1,758,192 5/1930 Grubman 83-465 X 2,329,020 9/1943 Wales 8354 2,917,033 12/1959 Brogren 123-90 3,074,302 1/1963 Coulon et al. 83-54 3,134,422 5/1964 Cranberg 83-191 3,153,897 10/1964 Kummerer et a1. 83-620 ANDREW R. JUHASZ, Primary Examiner.

Claims

4. A METHOD FOR PRODUCING A SUBSTANTIALLY CIRCULAR OPENING IN A SIDEWALL OF A ROCKER ARM WITH A SUBSTANTIAL EDGE PORTION OF SAID OPENING BEING SUBSTANTIALLY COEXTENSIVE WITH AN ARCUATE BOTTOM WALL THEREOF EXTENDING TRANSVERSELY OF THE SIDEWALL, SAID METHOD COMPRISING SUPPORTING A PUNCH WITHIN SAID ROCKER ARM AND SUBSTANTIALLY TANGENTIALLY TO THE BOTTOM WALL OF THE ROCKER ARM, BACKING UP SAID SIDEWALL AROUND A PORTION THROUGH WHICH SAID OPENING IS TO BE PRODUCED, MOVING SAID PUNCH TOWARD AND THROUGH SAID SIDEWALL, AND FIRMLY SUPPORTING A SUBSTANTIAL PORTION OF SAID BOTTOM WALL OF SAID ROCKER ARM ADJACENT WHICH THE OPENING IS MADE TO PREVENT MOVEMENT OF SAID BOTTOM WALL AWAY FROM SAID PUNCH AS SAID PUNCH APPROACHES SAID SIDEWALL ADJACENT SAID BOTTOM WALL.