FR2494610A1 - METHOD OF MAKING THE BEVEL OF ARMS OF VILEBREQUINS, ETC., AND MILLING MACHINE FOR CARRYING OUT SAID METHOD - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND TO A CHIP REMOVAL MILL. THE MILLING MACHINE, ACCORDING TO THE INVENTION, WHICH INCLUDES A TOOL-HOLDER CARRIAGE 4 WITH CROSS-MOVEMENT AND A LONGITUDINAL CARRIAGE 5, IS EQUIPPED WITH A CONTROL DEVICE ALLOWING THE MILLING TOOL M TO COMPLETE A MOVEMENT WITH AXIAL COMPONENTS RADIALS. THE MACHINE IS APPLICABLE TO THE BEVEL SIZE OF THE CRANKSHAFT ARMS.

Description

The present invention relates to a method for producing

  the bevel of crankshaft arms or the like,

  by machining with chip removal, as well as

  only for the implementation of this process.

  Especially in the case of crankshafts large enough and

  quite heavy, the arms are often canted to the lateral faces

  outside the area of the crankpins on the one hand to save material and weight and on the other hand

  to save space in the crankcase or similar

  ford. So far, these bevels form flat surfaces or conical surfaces and require considerable manufacturing expense. Indeed, after machining the crank pins with a

  conventional milling machine for crankshafts, it is necessary to transfer

  cranes on a lathe or a mill specially designed for this purpose and only then does the machining of the bevels of arms. We can not avoid transferring the coin unless, at

  once again, after milling the crankpins, the

  it itself by replacing the milling plate by an additional group with own drive which then allows the machining of the bevel. As tools, we use lathe tools or

  suitably chosen strawberries that are dipped radial-

  or guided with a transversely directed advance

  to the axis of the crankshaft. Therefore, given the neces-

  to transfer the workpiece or to convert the machine, the known processes of machining of bevels of arms with removal of

  chips are long and require significant additional

  because of the need for machines, additional groups,

positive and special tools.

  This is why the invention aims to eliminate these disadvantages and to provide a method of the species defined above which allows to realize bevels of arms with economy

  time, in a rational and practical way, without

  etc. According to the invention, this problem is solved by the fact

  that the region is to be bevelled by the arm along an over-

  cutting face generated by an arc of a circle located in a normal plane to the axis of the crankshaft and whose center moves on a path whose pace comprises axial and radial components. This method, which leads for example to a bevel in the form of a cylindrical surface if the trajectory of the center of the arc is rectilinear, allows the use of disk mills.

  simple with an outer or inner cut whose circle of

  mes has a radius corresponding to the arc of the circle and it is enough to communicate with the strawberry a advance adapted to the trajectory of the

  center of the arc to make the desired arm bevel

  re. Such an internal or external cutter can be mounted

  without difficulty on any milling machine for crankshaft

  quins, so that the bevel of a crankshaft can be made on a milling machine for crankshafts, with the same

  fixing of the workpiece and without the addition of a group

  nel. Since the important point is not the shape of the bevel, but the saving of material and space, the absence of conical bevels is of no importance, but if, in special cases, such a bevel bevel was necessary, we could

  by the method according to the invention to approach this surface co-

  for example by machining the bevel along two surfaces

  of cutting whose arcuate trajectories would be

  killed in two symmetrical axial planes around the axial plane passing through the radius of the crankshaft. Of course, at the same time as the advance, one can freely choose the shape of the trajectory in an arc and thus the shape of the bevels, for example, apart from the rectilinear shape, a convex shape or

  concave and naturally, by the method according to the invention,

  be the bevels of the crankshaft arm, it is also possible to realize

  other bevels on parts that can be machined

born on milling machines.

  For the rational implementation of the method, according to a development of the invention, in a milling machine comprising a tool carriage that can move transversely to

  the longitudinal axis of the machine and receiving a milling tool

  wise, preferably annular in inner cut, and a carriage

  longitudinal section carrying the tool carriage, provision is made for a

  positive control by means of which it is possible to control both the drive of the tool carriage and the drive of the longitudinal carriage to print to the milling tool a

  advance movement comprising radial and axially

  the. Only under this control device, one can

  use a standard milling machine without other addi-

  to machine bevels of the arms, because the advance corresponds to

  of the tool is given by the combination of movements

  tool carriage and longitudinal carriage. The tool trolley can be a cross-moving trolley as well as a cross trolley.

  in the case of the transverse carriage, ensure an angu-

  corresponding crankshaft so that it also performs a movement of the transverse carriage in the correct position

  relative to the radius of the crankpin in question and that it

  the desired radial component of the advance. Such a di-

  crankshaft vision is not necessary in the case of a cross-moving carriage, because with this one, the tool can

  anyway be moved in any direction ra-

Diale.

  It is particularly advantageous, according to the invention to use as a milling tool a milling plate that can be used to machine the trunnions and / or the outer contour of the arms. As a result, a milling plate of this kind makes it possible to mill the trunnions and / or the outside contour of the arms, as well as to machine the bevel of the arms of a crankshaft during a single fastening and with the same milling tool. There is no need for transfer, conversion or transformation, and once the workpiece is fixed it can be machined in one pass at any time.

desired places.

  The subject of the invention is represented by way of example

  by the accompanying drawings, in which:

  Figures 1 and 2 show schematically the execution

  tion of the method according to the invention, with regard to an arm of

  brequin in side elevation and frontal and figure 3 a milling machine for the implementation of the

  method of the invention, in side elevation.

  In order to be able to make a bevel 2 on the arms of a crankshaft 1 with a conventional milling machine for crankshafts equipped with a milling plate M in the form of a disc, this bevel is machined in a substantially cylindrical form and, for this purpose,

  the milling plate M is communicated, which is in the example

  presented an annular milling cutter with inner cut, a

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  in which the principal direction is composed of a component

  Radial health VR and an axial component VA 'Under this advance V, It is formed during milling with the plateau

  miller M a bevel of arm 2 which is the intersecting surface

  between the arm la and the enveloping surface of the circle of

  lamnes K corresponding to the advance of the milling plate M. The advantage

  this V and the trajectory of the center of the milling plate during the milling can in principle be chosen freely as long as their pace has not only a radial component but also an axial component, the course can naturally also include a variable direction of pace

  and sections with an exclusively radial or vertical component

  the. Since such a trajectory must be completed during the advance of the tool, it is necessary logically, in the choice

  of this trajectory or route in advance, take care of the pos-

  practical execution and efficiency.

  Figure 3 shows a milling machine for crankshaft

  which allows, with the same milling plate M and during the same attachment of a crankshaft 1, not only to machine the pins lb, the crank pins and the outer contour la 'arms, but also to achieve the bevel 2 of the arms. For this purpose, the annular milling plate with inner cut M is mounted via a tool drum 3, in a

  tool carriage 4 in the form of a carriage with crossed movements

  which consists of a horizontal carriage 4a and a vertical carriage 4b and allows any displacement of the tray

  miller M in a plane normal to the longitudinal axis of the machine.

  china 4. The tool carriage 4 is mounted in turn on a longitudinal carriage 5 which can slide longitudinally along the bench 6 and ensures the movement of the milling plate M in the axial direction. For driving the horizontal and vertical carriages 4la, 4b are provided motors 7 which move the

  trolleys 4a, 4b via corresponding transmissions

  Threaded rods and rods 8, 9. A motor 10 with rod file-

  1l feeds the longitudinal carriage 5.

  On the bench 6 of the milling machine are also arranged

  two dolls 12 which immobilize the crankshaft to be machined 1 pen-

  dant tt - te: nps from IusinaFce. To keep the crankshaft 1 during machining by the milling plate M is further provided a bezel 14 which is also mounted so as to slide on the bench 6 and can optionally be coupled

to the longitudinal carriage.

  To control the movements of the trolleys and the trolley drives there is provided a control device 13 through which the trolley drives can

  be controlled so that the milling plate M is po-

  longitudinally in accordance with the machining points and

  executes the advance movement required for the desired machining.

  When machining the pins 1b and the crank pins 1c as well as the outer contours 1a of the arms 1a, this advance movement is in a plane normal to the longitudinal axis of

  the machine and therefore it is ensured only by the

  If, on the other hand, the bevels of arms 2 are machined, the feed must have a radial component and a

  axial component, so that the drive of the truck lon-

  5 must be ordered not only for the position

  longitudinally of the milling plate, but also for the advance of it. The feedrate V of the milling plate M for the machining of the bevels of arm 2 thus results from the combination of the movement of the tool carriage in a normal plane and in the appropriate direction, for the component VR, and the movement

  longitudinal trolley, in the axial direction, for

  suits you. The magnitudes of the components that determine each

  time and their cooperation can be chosen

  via the control device and are also

  if monitored by this one. Thus, with a single milling machine and a single tool, it is possible to machine in the most rational way the trunnions, the crank pins, the external contours of the arms

and the bevel of the arms.

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Claims (3)

  1. Process for producing the bevel of the arms of town   breeds, etc., by machining with chip removal,   characterized by the fact that the region is machined to be canted of the arm along a cutting surface generated by an arc of a circle situated in a plane normal to the axis of the crankshaft and whose center moves on a trajectory of which the pace includes   axial and radial components.   2. Milling machine for carrying out the method according to claim 1, comprising a tool carriage movable transversely to the longitudinal axis of the machine and receiving a milling tool, preferably annular inner section, and a carriage longitudinal axis carrying the tool carriage, and characterized by a control device (13) by which both the drive (7, 8, 9) of the tool carriage and the drive (10, 11) can be controlled. longitudinal carriage for printing to the milling tool (M) a feed movement (V) comprising radial and axial components (VR, VA) 3. Milling machine according to claim 2, characterized in that the milling tool is a milling plate (M)   which can be used to machine the pins (lb, le) and / or the outer tower (the ') of the arms.