EP0683012A1 - Metal rolling machine with opposite rows of claw units for machining a centered workpiece and method for rolling rotary grooves of a workpiece - Google Patents

Abstract

The machine has first and second swinging arms, mounting fixtures, pintles and clamping jaw assemblies. Each jaw assembly has an upper and lower jaw and a pintle which provides their rotatable connection. Each of the jaw assemblies has a mounting for holding the working tools for simultaneous machining of the material of the adjacent channels of the crank journal seats by rotation of the crank around the crankshaft's rotational axis. <IMAGE>

Description

Field of the Invention

This invention relates to metal working, more specifically to a new and improved machine for rolling fillets of metallic workpieces and to a new and improved method for simultaneously rolling all or a number of fillets of a workpiece such as e.g. the fillets of crank pins of an engine crankshaft.

Description of the prior art

Prior to the present invention, various machines and methods have been used to machine metallic workpieces such as e.g. To consolidate and finish camshafts and crankshafts for internal combustion engines. Since many motors have been downsized to be installed in smaller vehicles, difficulties have been encountered in finishing and hardening the correspondingly reduced workpieces. For example, it is very difficult to secure the crank pins of reduced crank shafts with optimized effectiveness because the lengths of the crank pins are so small that there is insufficient space for a tool to simultaneously roll all fillets in a single rolling operation.

Verfahren und Vorrichtung zum Feinwalzen und Festwalzen von mehrhübigen Kurbelwellen" eine Maschineneinheit und ein Verfahren zum Walzen von Zapfenhohlkehlen einer Kurbelwelle offenbart, um die Probleme zu lösen, die das gleichzeitige Walzen von benachbarten Kurbelzapfen mit der verfügbaren Ausrüstung ausschließen. In dieser Patentoffenbarung nehmen die Maschineneinheit und die Kurbelwelle eine erste relative Lage zueinander ein, so daß die Hohlkehlen eines ersten Satzes von nicht benachbarten Zapfen festgewalzt werden können. Daraufhin werden in einer zweiten relativen Lage der Maschineneinheit und der Kurbelwelle die Hohlkehlen eines zweiten Satzes von nicht benachbarten Zapfen festgewalzt. Mit einem derartigen Aufbau und einem derartigen Verfahren werden alle Hohlkehlen in zwei Etappen oder zwei Verfahrensschritten durch eine einzelne Maschine gewalzt.Prior to the present invention, such crank pins and main bearings for downsized crankshafts, as well as crankshafts for larger engines, have been strengthened by various fillet rolling machines and processes. For example, in U.S. Patent 5,138,859 to Winkens, published August 18, 1992, for a

Method and apparatus for multi-stroke crankshaft rolling and deep rolling "discloses a machine unit and method for rolling crankshaft journal grooves to solve the problems that preclude the simultaneous rolling of adjacent crankpins with the available equipment. In this patent disclosure, the machine unit and the crankshaft a first relative position to each other, so that the Fillets of a first set of non-adjacent tenons can be rolled. The fillets of a second set of non-adjacent pins are then rolled in a second relative position of the machine unit and the crankshaft. With such a construction and method, all fillets are rolled in two stages or two process steps by a single machine.

Although such machines and processes are effective and produce work of high quality, new and improved machines and processes are needed to meet higher standards for machine efficiency with high output and long life that include excellent parts such as e.g. Manufacture high quality crankshafts with deep-groove hardened by deep rolling.

Co-pending U.S. Application No. 176,792, filed January 3, 1994, assigned to the assignee of this invention and incorporated by reference herein, describes equipment, tools, and methods for rolling fillets of a workpiece using fillet claw arms one side of a crankshaft are arranged in stepped sets, so that all the pin grooves of a crankshaft can be rolled in one rolling process.

Applicant's Laid-Open No. 353,030 of April 22, 1994 discloses aspects of this invention and is incorporated herein by reference.

The present invention relates to a machine, tool and method similar to that disclosed in copending application No. 176,792, but further enhancing this technique by providing new and improved methods, rolling equipment and tools that are suitable for a wide range of applications are suitable, in particular those in which simultaneous rolling of the fillets from opposite sides of the workpiece or the crankshaft is necessary or desired.

It is important to say that the present invention solves the space problems encountered in many facilities in which shuttle tools are required to roll the closely spaced or adjacent fillets, which complicates the use of bulky, side-by-side rolling equipment or even excludes.

A preferred embodiment of the machine of this invention has opposed rows of fillet roller claw units capable of simultaneously deep rolling all fillets of a crankpin seat including the adjacent crank seats and also the main bearing seats of a crankshaft.

In this invention, the opposing rows of fillet roller claw units can be moved toward and away from each other simultaneously between (1) an open position in which unfinished workpieces such as e.g. Crankshafts can be loaded into the lathe or finished workpieces can be unloaded from the lathe, and (2) a closed position in which the fillet rolling tools engage in all or a number of the crankpin fillets including the fillets of adjacent crankpins and also in the main bearings that they can be rolled and solidified at the same time.

This invention further relates to methods of simultaneously rolling fillets of workpieces such as e.g. Crank seats of an elongated internal combustion engine crankshaft, comprising the steps of: (a) inserting one end of the crankshaft into the vice of a power lathe and the other end into a bracket of the machine so that the crankshaft can be driven by the machine about its axis of rotation, (b ) Arranging the left and right side rows of the fillet roller on the left and right side of the axis of rotation, respectively, so that the claw arms of the device extend substantially transversely to the axis and make it possible to load an unprocessed crankshaft into the lathe, (c) moving the left and right side rows of the device from an initial position spaced from the crankshaft to a position where the fillet rolling tool held on the claw arms contacts the fillets of the pin seats, (d) applying a load to the pin seats by the claw arms and the tool, (e) driving the lathe e to rotate the crankshaft about the axis while the tool pressurizes the fillets so that the tool simultaneously machines and hardens the fillets of the pins and the headquarters, (f) opening the claw arms and removing the rolled crankshaft from the machine.

The present invention is illustrated in the following detailed description and drawing, which shows:

Brief description of the drawing figures

Figure 1

Fig. 4 is a pictorial illustration describing the outline of a preferred embodiment of the fillet rolling machine and method according to the present invention;

Figure 2

Fig. 3 is a sectional view, with some parts in solid lines, taken substantially along lines 2-2 of Fig. 1 and showing how the fillet rolling tools roll the fillets of adjacent crankpins separated by webs from a crankshaft;

Figure 3

Figure 2 is a view similar to that of Figure 2, illustrating another embodiment of rolling dies that roll fillets from adjacent crank pin seats not separated by webs;

Figure 3a

3 is a view similar to the views of FIG. 2 and FIG. 3, showing how the tool of FIG. 3 is used to roll crank pins of the crank of FIG. 2 separated from webs;

Figure 3b

Figure 3 is a diagram showing the overlapping crank pins of Figure 3a;

Figure 4

Figure 2 is a diagrammatic side view of the tool of Figure 2, taken substantially along lines of sight 4-4 of Figure 2;

Figure 5

Fig. 3 is a diagrammatic front view of the machine of a preferred embodiment of the fillet rolling machine of this invention, showing the rows of the machine in a retracted position for loading or unloading the workpiece;

Figure 6

5 is a view similar to that of FIG. 5, but with the rows moved inwardly from the position of FIG. 5 to a machining position in which the fillet rolling tools engage the fillet of the crankshaft;

Figure 7

Figure 6 is a diagrammatic plan view of a portion of the machine of Figure 6 taken generally along lines of sight 7-7 of Figure 6;

Figure 8

Figure 5 is a diagrammatic side view of part of the fillet mill of Figures 5 and 6, taken generally along lines 8-8 of Figure 6.

Detailed description of the drawing figures

The drawing figures are discussed in more detail below. FIG. 1 depicts part of a machine 10 for rolling the fillets of the seats of a workpiece, which are shown here as angularly offset and adjacent crank pins 12, 14 of an elongated crankshaft 16 of an internal combustion engine.

The crankshaft 16 is mounted in a workpiece rotating lathe 17 or other mechanism with the front end or flange end 18 of the crankshaft mounted in the chuck of the driving stick 20 and the opposite end on a centering mandrel 24 of the lathe tailstock. The drive stick is selectively rotated by a motor 30 so that the crankshaft 16 rotates about its axis of rotation 32.

The fillet rolling machine 10 has left and right side rows 36, 38, each of which has a plurality of oscillating claw units 40, 42. Each oscillating claw unit consists of upper and lower claw arms 44, 46 (left side row of the claw units 40) and 48, 50 (right side row of the claw units 42) which are rotatably connected between the inner and outer ends thereof by pivot pins 52, 54. The outer ends of each pair of arms are operatively connected by individually extendable and contractible pneumatic or hydraulic drive cylinders 56, 58 or other suitable control actuators which apply compressive force to the fillet machining rolls for rolling the fillet of the crank pin upon expansion. Each drive cylinder has a piston with a connecting rod 60 or 62 which is rotatably connected to a lower arm, while the corresponding cylinder tube projects into a fork shoe 64 or 66 which is rotatably connected to a corresponding upper claw arm 44 or 48.

The inner ends of the upper and lower arms of each claw unit face each other directly and are angularly offset with upper and lower tools 68, 70 or 72, 74 (Figure 2) for deep rolling annular grooves 86, 88 and 90, 92 and adjacent crank pins 12, 14 of the crankshaft 16, which are separated by annular webs 94, 96. The lower tools 70, 74 are secured to the lower arms of the left and right claw units and have pairs of spaced support rollers 98, 100 which engage and support the pin seats while their fillets are being rolled. Such lower support tools are disclosed in more detail in copending U.S. Application No. 176,792, referred to above.

Each left side 36 claw unit 40 and each right side claw unit 42 is supported by a respective upper swing arm 104, 106 rotatably mounted on the left and right sides of movable upper frames 108, 110 and suspended therefrom, the frames 108, 110 are mounted on a rectilinear slide mechanism or on carriages 112, 114 (Figures 5 and 6) running along front and rear horizontal support rails 116, 118. The rails 116 are in turn fastened on a support beam 120 which is held by stands 122 which are fastened on the floor or a base plate 124. Actuators such as hydraulic drive cylinders 126, 128 are operatively connected to the left and right frames 108 and 110 and can be individually driven to move the frames and the associated rows of oscillating claw units operatively connected thereto between a retracted position (Figure 5 ) for loading and unloading the workpieces and a closed position (Figures 6 and 7) for the deep groove rolling process. After the crankshaft 16 is inserted into the claws of the claw units, each side is individually engaged with the seats so that the rollers 138, 140 of the tool 68 and the rollers 142, 144 of the tool 72 into the grooves under a predetermined load intervene, the optional eg can be changed by selectively changing the expansion force applied by the cylinders 56, 58.

The drive motor 30 is connected to the chuck of the drive stick 20 and can optionally be actuated for rotatingly driving the crankshaft 16 about its axis 32. The pairs of clamp claws are pivotally attached to swing arms 104, 106 which are rotatably attached to the upper support structure provided by frames 108, 110. If the engine rotates the crankshaft for the deep rolling process, oscillate the arms on an arcuate path and the separate pairs of claws follow the circumference of the radially offset crank pin rotation axis 32 to machine and roll the fillets of these crank pins. The rolling pressure is built up by the expansion force of the cylinders 56, 58. As is known in the art, deep rolling of circular fillets works on the metallic structure of the fillets to secure the fillets and the crankshaft.

Each of the upper tools 68 and 72 carried by upper arms 44, 46 on the left and right sides of the claw units includes a housing which is releasably secured to the upper claw of each arm by fastening units 48, 150. Each housing has a support roller 152, 154 which is seated on needle bearings which are held on centrally aligned hubs 156, 158 arranged between the housing side plates.

The hardened fillet rollers, e.g. rollers 138, 140 are for rotation about mutually inclined axes A, A 'on the lower sides of the tools by cages such as e.g. Cages 160 and opposing adjustable screws 162 are adjustably attached. The cages have pockets 164 formed therein in which the hardened steel or other suitable material rollers are operably arranged. These fillet rollers touch corresponding annular running surfaces 166, 168 in the support rollers, so that locally limited rolling loads can be exerted on the fillets by the claw arms. When the crankshaft is rotated by operating the lathe motor, the rollers contact the front pairs of grooves 86, 88 and 90, 92 of the adjacent pins of the crankshaft so that the grooves are rolled under pressure and machined when the crankshaft is rotated.

The transverse side loads resulting from the rolling operation with the tools shown in FIG. 2 are offset against one another because the rollers 138, 140 and the rollers 142, 144 in each of the tools have equally large and opposite inclinations. In the event that the crankshaft, as shown in FIG. 3, has no webs between the angularly offset pins 12 ', 14', only the fillets 86 'and 92' are rolled. A ball bearing unit 170 with a cage is arranged between the housing of the tools 68 ', 72' and enables the opposite side loads resulting from the deep rolling of the adjacent mortise grooves 86 'and 91' to be offset against one another as described in the also co-pending application 176,792 become. In order to facilitate movement of the sides of tools between the retracted and closed positions, the bearing unit 170 is held by one of the tools and engages the side of the other tool so that the side loads caused by the rolling of the adjacent and opposite flutes against each other To get picked up.

The diagram of Figure 3b shows the overlap (shaded connection surface F) that occurs between the adjacent and angularly offset crank pins 12 and 14 and on the inner grooves 88 and 90 with webs.

In order to strengthen this structure in an improved manner by rolling without the webs, e.g. to unnecessarily bend or move the webs 94 and 96, the fillets 86, 88 and 90, 92 are first rolled with the tool from FIG. 2, preferably with variable rolling pressure, so that the sheet 12 '(dashed line) and 14th '(solid line) of the overlap is rolled at high pressure for deep machining and hardening of the inner grooves 88 and 90 in these areas. The remaining arcuate portions of the inner fillets are rolled at a lower pressure sufficient to leave the webs 94, 96 intact.

Accordingly, there is no overbending of the webs at this point. The outer grooves 86 and 92 are then rolled with the tool shown in FIG. 3a, with constant or variable pressure, so that the outer grooves 86 and 92 are completely rolled and fixed. This process can also be reversed, wherein, as shown in FIG. 3a, the outer fillets are first rolled and strengthened, and then the inner fillets 86 and 90 are rolled with variable pressures as described.

In Figure 5, the machine is shown diagrammatically as a front view, with the crankshaft 16 with radially offset pins inserted into the central lathe, and with the rows 36, 38 of the jaw units from each other and from the crankshaft by operating the drive cylinders 126 , 128 are moved away, the cylinder tubes of which are fastened to the stands 174, 176, which are fastened at their lower ends to the fixed rails 116, 118 and which in turn are fastened to the base plate 124.

Middle tool lifting sections 180, 182 of control and counterweight cylinders 184, 186 have fork shoes at their upper ends that are rotatably attached to eyelets that extend from the upper ends of the posts 190, 192 of the upper frames of the left and right Rows of claw units extend and have lower ends that are pivotally attached at 194, 196 to the upper claws 44 and 48. The lifting portions can be selectively actuated to cause the jaws of the jaw units to open so that the crankshaft mounted in the center lathe 16 can be loaded into the rows of the jaw units when the rows move to the rolling position move from Figure 6. The claws of the units are subsequently closed by expanding the cylinders 56, 58, while the tool lifting sections 180, 182 of the control and counterweight units are disabled. Accordingly, the crank pins are gripped by the tools with a force which is low but sufficient to hold the crank shaft against rotation.

The actual rolling of the fillets is then started by turning the crankshaft by the motor 30, the force exerted by the rolls on the fillets being increased up to the deep rolling force in that the force exerted by the cylinders 56, 58 on the corresponding claw units increases becomes. The rolling force can be changed during rolling since the crankshaft is driven in rotation until the fillet rolling is finished. The claws and tools follow the circular path of the corresponding pins to be rolled and the connected swing arms swing or swing back and forth along an arc to enable a swinging movement. The control and counterweight cylinders 186, 188, which is rotatably secured between the upper holding structure and the lower claw arms, can have a stroke changing section 196, 198 so that different crankshafts can be rolled with different crank pin positions. The cylinders 186, 188 have additional pneumatic spring counter sections 200, 202. The spring section is similar to a gas spring and serves to smoothly move the arms of the claw units while the fillets are being rolled.

Figure 7 is a top view of the left and right rows of pivot arms which roll the offset crank pins shown in dashed lines in the drawing. It can be seen that this arrangement provides the rolling pressure to the claw units required cylinders can be easily used in the machine, since the cylinders and the claw units for adjacent pins are operably mounted on opposite sides of the crankshaft. The left row is for rolling the one set of pins and the right row is for rolling the set of pins adjacent to the first set of pins. According to the invention, there is accordingly sufficient space to roll all fillets and, if desired, the main shaft bearings 210, 212, 214 simultaneously in one machine. As best shown in FIGS. 7 and 8, the fillet rolling claws of the claw units 216, 218, 220 similar to the disclosed ones have tools such as that in FIG. 2 that can be used to roll the fillets of the main bearings while the trunnion fillets be rolled.

Since a preferred embodiment of the invention has been illustrated and described, other embodiments will become apparent to those skilled in the art. Accordingly, the invention is not limited to what has been shown and described, except by the following claims.

Claims (8)

Machine for the permanent strengthening of a ductile iron crankshaft for an internal combustion engine with a central axis of rotation and a plurality of crank pin seats parallel to this axis of rotation by simultaneously machining the material of adjacent and facing fillets of cylindrical crank pin seats, the machine comprising: first and second brackets, first and second Swing arms, first and second pivot pins operatively connecting the first and second swing arms to the first and second brackets, first and second sets of jaws extending laterally from opposite sides of the crankshaft toward the crankshaft, each jaw set having a lower jaw and an upper jaw and has a pivot pin which rotatably fastens the lower claw and the upper claw to each other, each of the claw sets having a tool holder for holding the tools for the simultaneous processing of the material from n adjacent and facing grooves of the crank pin seats by rotating the crank about the axis of rotation, whereby the swing arm supporting the corresponding claw set swings on the pivot pin and oscillates at an angle while the claws of each of the claw sets move around the corresponding crank pin seat. Machine for the permanent strengthening of a ductile iron crankshaft for an internal combustion engine by simultaneously machining the material of adjacent and facing fillets of cylindrical crankpin seats of the crankshaft, which are offset from one another and have central axes parallel to the axis of rotation of the crankshaft, comprising: holders, first and second rocker arms, the rocker arms pivot pins operatively connecting the brackets, first and second sets of clamp claws located on opposite sides of each set of claws, each set of claws having a lower claw and an upper claw and a pivot pin which rotatably secures the lower claw and the upper claw to each other, additional pivot pins for connection the lower claw with the corresponding swing arm, each of the claw sets having a pair of claws forming tool holders, with tools operatively arranged in the tool holders conditions for the simultaneous processing of the material of adjacent and facing the crank pin seats by driven rotation of the crank about the axis of rotation, whereby each swing arm supporting the corresponding claw set moves on an arc and the claws of each of the claw sets move around the corresponding crank pin bearing and the tool bypasses the seats and the annular fillets completely processed. A machine for simultaneously machining the fillets of pairs of immediately axially connected and angularly spaced annular seats of an elongated crankshaft with an axis of rotation and in response to the driven rotation of that crankshaft, comprising:
several pairs of pendulum tool holders, which are formed on upper and lower lever arms,
a first bracket for supporting a first of the two pairs on one side of the crankshaft and a second bracket for operatively supporting a second of the pairs on the opposite side of the crankshaft,
first and second actuating devices for moving the tool holders towards and away from each other,
each of the lever arms has individual front and terminal end sections,
Pivots pivotally connecting an upper lever arm and a lower lever arm of each pair of lever arms between the front and terminal end portions thereof, the upper and lower lever arms of each pair of lever arms having force-receiving ends near their terminal end portions and force-applying claws at their front ends,
opening and closing force generating means operatively connected to the terminal end portions of each pair of lever arms and operable to open and close the force-applying claws, and
tools attached to the force-applying claws for machining the fillets of the workpiece when the tool holders are moved to abutting points and in operative engagement with the adjacent fillets when the workpiece is rotatably driven about its central axis and when the force-generating device is actuated to cause a work load on the tools by the device for generating a closing force on the claws. The machine according to claim 3, wherein the machine rolls fillets of crankpins of a crankshaft for an internal combustion engine, and wherein the crankpins are formed in one piece and have centers that are angularly offset from one another and that are spaced apart in the radial direction from the axis of rotation of the crankshaft. A machine as claimed in claim 3, in which the supports extend above the crankshaft, and in which pivot arms and pin connections are provided rotatably attached to these supports, the pivot pins rotatably connecting each pair of lever arms to one another so that the pairs of arms can swing when that Workpiece is rotated about the axis of rotation. A method for simultaneously rolling the fillets of a plurality of seats of an elongated internal combustion engine crankshaft with an axis of rotation and with a plurality of pairs of adjacent crank pin seats, comprising the method steps: a. Inserting one end of the crankshaft into the drive shaft of a motor-driven crankshaft lathe and inserting the other end into a support of the machine so that the crankshaft can be driven by the machine around its axis of rotation, b. Disposing left and right fillet rolling machines, each having a plurality of pairs of elongated and rotatably connected lever arms on the left and right sides of the crankshaft so that the lever arms extend generally transverse to the axis of the crankshaft, and so that the Crankshaft can be inserted into the lathe c. Moving the left and right fillet rolling machines from their initial position onto the crankshaft to a position where the tools carried on the ends of the lever arms contact the pairs of pin seats, d. Applying a load to the pin seats by the lever arms and the tool, e. Driving the crankshaft rotating machine so that the tool rolls and simultaneously machines the fillets of the plurality of pairs of pin seats, f. Open the lever arms and remove the rolled crankshaft from the machine. A method for simultaneously rolling the fillets of a plurality of seats of an elongated internal combustion engine crankshaft with an axis of rotation and with a plurality of pairs of adjacent crank pin seats with fillets, comprising the method steps: a. Providing a drive motor for rotating the crankshaft about its axis of rotation, b. Providing left and right fillet rolling mechanisms, each having a plurality of elongated fillet rolling arm portions on opposite sides of the axis of rotation so that the mechanism's rolling arms generally extend toward and towards the axis of rotation, c. Moving the left and right fillet rolling mechanisms away from each other so that the crankshaft can be loaded into the drive tool d. Inserting the crankshaft into the drive tool so that the tool can be rotatably driven, e. Moving the fillet rolling mechanisms to a rolling position to roll the fillets, the fillets being operably contacted by the rolling mechanisms, and f. Rolling the fillets in response to the drive motor rotating the crankshaft. A method of deep rolling the fillets of a pair of overlapping and angularly offset crank pins of a crankshaft for an internal combustion engine, the crank pins having pairs of inner crank pin grooves with a web therebetween and outer crank pin grooves, comprising the method steps:
Deep rolling the inner fillets of each of the crank pins, wherein the angular overlap area of the inner crank fillets is rolled with a higher pressure than the remaining angular sections in order to optimize the integrity of the webs,
then deep rolling the outer fillets of the crank pin seats with substantially constant pressure to completely solidify the outer fillets and the crankshaft.

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