WO1999065645A1

WO1999065645A1 - Control cam set

Info

Publication number: WO1999065645A1
Application number: PCT/DE1999/001713
Authority: WO
Inventors: Wolfgang Drees
Original assignee: Wolfgang Drees
Priority date: 1998-06-15
Filing date: 1999-06-11
Publication date: 1999-12-23
Also published as: DE19826243B4; DE19826243A1

Abstract

The invention relates to a control cam set with a working cam and a recoil cam, in which no bending moment is generated and in which the working roller and the recoil roller can roll with no play. The rotational masses of said set are minimized enabling simple angular displacement in relation to the working cycle and rapid replacement. It is well centered and can be mounted and fixed easily. This is achieved in that the working cam (1) and the recoil cam (2) are embodied as a single unit forming a control cam set that is fitted with front teeth (7).

Description

S t e u e r k u r v e n s α t z

The invention relates to a Steuererkurvensαtz according to the preamble of the main claim.

Control shafts with control cams have been used for the automation of machine tools since the 19th century. The control cams control the feed movement of the tool either directly or via a connecting mechanism. Directly controlling control cams must be exchanged to change the feed movement; the control cams are adapted to the workpiece. If the gear ratio between cam stroke and feed movement can be changed via the connecting mechanism (e.g. link lever), different feed paths can be realized with the same control cam.

Many cam-controlled machines are equipped with universal cam sets to achieve a high degree of flexibility, which are used to actuate a mechanism with an actuator. The actuation of the adjusting element is intended for small changes in the feed movements, the selection of a different control curve from the universal curve set, however, for larger changes in the feed movements. Both drum and disk curves are used in cam-controlled machines, the disk curves being used with particular preference in areas with high flexibility requirements and small installation space. A feed drive for tool cross-slides on machine tools, in particular multi-spindle automatic lathes, is known, DE 23 39 190 B2, which, however, has the disadvantage that the one-sided mounting of the working roller generates a bending moment on the roller bolt under load. The resulting inclination of the work roller to the cam track leads to wear due to edge pressures and has a disadvantageous effect on the rigidity of the control. It also contains relatively large rotational masses. This known solution also absolutely requires play in the guidance of the work roll, which places narrow limits on exact guidance of the feed movement.

The invention is therefore based on the object of providing a set of control cams with a working curve and a retracting curve, in which no bending moments are generated and in which the working roll and the retracting roll can roll with as little play as possible. In addition, the rotary masses must be minimized and the angle of the work cycle simply adjusted. Furthermore, the cam set should be quick to change, easy to center and easy to install.

This object is achieved in connection with the preamble features according to the invention by the technical teaching specified in the characterizing part of the main claim. The lifting and retracting curve is designed as a structural unit for a control cam set with a double inner curve for a V- or Y-shaped cam lever and is provided with spur gearing for quick assembly, exact centering and simple fixation, particularly in a machine tool designed as a multi-spindle automatic lathe.

A particular advantage of such a control cam set is that it requires that the control cams be properly centered, on both sides Storage of the work roll, a play-free guidance of the feed, low rotary masses of the control shafts with control cams, a quick possible exchange of the control cams as well as easy adjustment of the angle of the control cams to the work flow.

The control cam set is arranged and designed in such a way that a quick change is possible in the area of the control cam / cam lever if the control is extremely rigid. The invention is independent of the manner in which the feed movement is transmitted from the cam lever to the workpiece - tool - pairing.

The connection of two control curves designed as internal curves outside the machine enables the use of spur gearing to fasten both control curves. This makes it possible to quickly change the control cams with just one nut or screw to be loosened. The self-centering spur gear ensures a central arrangement of both the work and the retraction curve. It also includes the potential for angularly turning the work curve to the overall process of the machine. At the same time, by connecting the control cams outside of the machine, it is easy to ensure that the retraction curve is in line with the work curve.

The advantages of the double inner curves, such as low rotary masses and work and retraction rollers that can be supported on both sides, can be used with this solution.

The production of the two inner curves for a control curve set can in principle be carried out separately if the curve path of the retraction curve is calculated as a coupling curve, connected via the Y-curve lever for a given distance from the cam shaft and lever axis, of the working curve. Important here. is that both control cams have the center of the spur toothing as the center and during their manufacture, provided that the control cam set consists of one component, or assembly, provided that the finished working curve and the finished retraction curve are assembled into one unit, that they are at an angle to one another such that the retraction curve is the coupling curve the working curve is.

According to a preferred embodiment of the subject matter of the invention, the cam headset including the spur toothing is formed in one piece.

Of particular importance is also that with the inventive control cam set, absolutely play-free or even preloaded forced guidance of the working and retracting roles over 360 ° is possible.

To clarify the invention, the generally known prior art and then the invention are explained in more detail below with reference to the drawings:

1 is a view of the cam lever and cam set, Fig. 2 is a plan view of the subject of Fig. 1 in partial section,

3 is a plan view of a first Variant of the prior art,

4 is a view of the object of FIG. 3 in partial section,

5 is a plan view of a second variant of the prior art,

6 is a view of the subject of FIG. 5 in partial section, FIG. 7 is a plan view of a third variant of the prior art,

8 is a view of the object of FIG. 7 in partial section,

9 is a plan view of a fourth variant of the prior art,

10 is a view of the object of FIG. 9 in partial section,

1 1 is a plan view of a fifth variant of the prior art, FIG. 12 is a view of the subject of FIG. 1 1 in partial section, Fig. 13 is a plan view of a 6th variant of the prior art and

Fig. 14 is a view of the object of Fig. 13 in partial section.

Starting with a pure working curve 1, hereinafter referred to as variant 1, which is shown in FIGS. 3 and 4, in which the cam lever 5 is retracted by means of a spring force, disk cam sets for working stroke and retraction were developed in the 20th century in the following variants 2 to 6 and shown in FIGS. 5 and 14. In variant

2, the work curve 1 and the retraction curve 2 are each shaped so that a work roll 4 can roll through with a little play between the two tracks. The one-sided mounting of the working roller 4 generates a bending moment on the roller bolt under load. The resulting inclination of the working roller 4 to the cam track leads to wear via edge pressures and has a disadvantageous effect on the rigidity of the control.

From this experience, axially offset working curve 1 and retraction curve 2 with the same roller center path have been developed, in the following variant

3 and shown in Figures 7 and 8. A working roller 4 mounted on both sides enables higher rigidity with the same machine component dimensions.

The control cams of variants 1, 2 and 3 are attached using axially arranged screws or dowel screws. Corresponding drilling patterns of the control cams and / or cam supports often allow angular displacement of the control cams. This allows the individual feed movement to be shifted in the overall cycle of the machine.

As a further solution to the rigidity problem, the double inner curve with a V- or Y-shaped cam lever is used. nαnnt and is shown in Figures 9 and 10. These are axially offset working 1 and retraction curves 2 with different roller center points. The working curve 1 can be designed freely, the retraction curve 2 is created by the geometric coupling via a two-armed cam lever 5, hereinafter called the Y cam lever. In this embodiment, the retraction roller 3 can be mounted on both sides in addition to the working roller 4. The geometric arrangement allows the rollers 3, 4 to be guided without play. In addition, this variant has the advantage of low rotary masses, which is of great importance when changing the control shaft speed, for example when changing between working gear and rapid traverse. Such control curves are usually designed as segments and fastened by tangential screws.

Since the 1970s, cam disks and cam carriers with stamped spur toothing 7 have been used to change control cams faster. The centering and anti-rotation is done via the spur toothing 7 with a central nut or screw. Designed as a pot curve, called variant 5 below and shown in FIGS. 1 1 and 12, it solves the fastening and centering problems of variant 2. Here too, the work roller 4 is supported on one side.

The variant 6 shown in Figures 1 3 and 14 shows the possibility of a working roller 4 mounted on both sides in connection with a spur gear centering. Here, too, the control cams are arranged in two planes, the working curve 1 being centered by face gearing and held by a central nut or screw, the retraction curve 2, however, being fastened with screws.

A disadvantage of variant 1 is that in many cases it is not precise enough in the retraction behavior due to the lack of positive guidance. It also works the spring force in addition to the feed force on the work roller 4. Together with variants 2 and 3, this solution has the centering problem: only well-centered control cams result in the same end positions of the feed devices after repeated installation and can therefore be used without changing end stops (etc. ) it will be exchanged. This problem can be solved in all 3 variants by high demands on the precision of the assembly, which rules out a quick curve change. For example, after each curve change of variants 2 and 3, you must check whether the work roll is passed with enough play between work curve 1 and retreat curve 2.

A particular disadvantage of variant 4 is the fixed angular position of the control cams in the workflow. The tangential fastening of the curve segments does not allow any twisting in relation to the overall process. The exchange of the control curves is also very time-consuming.

With variant 5 there is a solution that can be exchanged quickly and easily, but which has disadvantages in terms of rigidity like variant 2. It also contains relatively large rotary masses.

Variant 6 solves the fastening and centering problem only for the working curve. The separate installation of both control cams leads to the necessity to check the continuity of the work rolls, as with variants 2 and 3. Variant 6 is therefore not to be regarded as quickly replaceable.

Except for variant 4, all known solutions require play in the guidance of the work roller 4. In these cases, there are limits to exact guidance of the feed movement.

Claims

Patent claims

1 . Set of control cams, in particular for mechanical controls in automatic lathes, with two control cams designed as a work and retraction curve, which is designed as a double inner curve for a V or Y-shaped cam lever, characterized in that the work curve (1) and the retraction curve (2) as Are designed to form a control cam set, which is provided with a spur toothing (7) for assembly, centering and fixing in an automatic lathe.

2. set of control cams according to claim 1, characterized in that the two control cams, the working curve (1) and the retraction curve (2), and the

Front toothing (7) are made from one piece.

3. Control cam set according to one of the preceding claims, characterized in that it is used with the cam lever (5) without play or with slight mutual bias in a machine tool.