JPS5854935B2 - Machine that precisely processes gears - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a precision machining machine using a gear-shaped tool by honing, cutting, or other machining method in which tooth side play occurs between the tool and the workpiece. The present invention relates to a type having a device for changing the pressure force of the tooth flanks that contact each other with a workpiece.

Numerous methods are already known for precision machining gears, and these methods have been improved with a series of models, devices, etc. in order to meet the ever-increasing demands of customers regarding tooth quality. However, slight errors, such as tooth surface shape errors, are still observed in the machined gears.

The cause of these errors is thought to be particularly the form of motion between the tool and the workpiece.

The object of the invention is to improve a machine of the type mentioned at the outset in order to increase the quality of the processed teeth.

In known gear precision machining machines, the tool is usually driven and the workpiece is carried along.

This applies to machining methods in which only one tooth side surface is in contact, as well as in machining methods in which both tooth flanks are in contact.

In machining methods in which only one tooth side is in contact, one tooth side of the driving gear (in this case, the tool tooth) is directly connected to one tooth side of the tooth of the driven gear (in this case, the workpiece). the other tooth flank of the same tooth of the driven gear has a predetermined spacing with respect to the corresponding tooth flank of the next tooth of the driven gear.

In other words, the tool and workpiece mesh with each other with play on the tooth sides.

On the other hand, in machining methods in which both tooth flanks are brought into contact, the tooth flanks on both sides of the workpiece tooth groove are in direct contact with both tooth flanks of the tool tooth, or vice versa. The tooth flanks on both sides of the workpiece are in direct contact with both tooth flanks of the workpiece tooth.

That is, there is no tooth side play between the tool and the workpiece.

When machining with only one side of the tooth in contact, the first contact between the tool and workpiece is always between the workpiece tooth head and the tool tooth root, regardless of the direction of rotation of the tool. .

The subsequent slippage between the two tooth flanks, which decreases to zero until the rolling circle is reached and then increases again, leads to irregularities in the tooth flank shape.

In other words, the tooth side surface of the workpiece deviates from the ideal involete shape.

To avoid this the tool had to be modified accordingly.

If the workpiece is driven instead of the tool and the tool is entrained, the first contact between the tool and the workpiece occurs at the root of the workpiece and the head of the tool.

In other words, it is exactly the opposite of when the tool is driven.

In this case, the sliding between the tooth flanks also takes place in the opposite direction.

Deviations from the ideal volute shape will therefore also be the opposite of when the tool is driven.

Starting from this recognition, the problem of the present invention is that when machining is performed with only one side of the tooth in contact, the tool and (
or) by both the tool and the workpiece engaged therewith being rotatably driveable so that the contacting tooth flanks can be loaded with varying crimping forces acting alternately upon acceleration or braking of the workpiece. Ta.

The invention will now be explained with reference to the drawings: FIG. 1 shows an example of a machine for precision machining gears according to the invention, a machine that works without vertical feed, that is, a machine that works by the plunge machining method. It is shown.

A tool holder 2 is rotatably and fixedly supported on a C-shaped machine frame 1 .

A tool 3 is mounted on this tool holder 2 in a known manner.

I will touch on the tool drive device later.

In addition, a carriage 8 is mounted on the machine frame 1 so as to be movable in the guide perpendicular to the pivot plane of the tool holder 9 and, if necessary, to be fixed.

A workpiece table 1 is arranged on the carriage so as to be tiltable about an axis 10.

The workpiece 4 is placed between the tailstock 5 and 6 on the workpiece table γ.
is installed.

This workpiece 4 meshes with the tool 3, preferably with its axes crossed, and can be driven by a motor 21, as will be described later.

The tilting of the workpiece table 7 about the axis 10 makes it possible to machine balloon-shaped teeth on the workpiece.

The carriage 8 is connected to a motor 11 or a handle 1 in a manner known per se.
3 through various transmission members.

That is, the workpiece is moved vertically in order to approach the tool.

The equipment necessary for this purpose is likewise known and is therefore not shown in the drawings.

The tool 3 connects the adjustable electric motor 14 to the gear transmission 1
5. Driven via spur gear sets 16, 1γ and bevel gear sets 18, 19.

However, an adjustable hydraulic motor can also be used instead of an electric motor.

It is generally advantageous to provide a clutch 20 between the motor and the transmission.

To drive the workpiece 4, an electric motor 21 of the same type as the motor 14 for driving the tool is used.

Of course, in this case also an adjustable hydraulic motor can be used instead of the electric motor 21.

A transmission 21' is connected behind the motor, and in this case too it is advantageous to arrange a clutch 22 between the motor and the transmission.

The motor 21, the transmission 21' and optionally the clutch 22 can be flanged together as a component to the tailstock 6 or can be fixed individually to the workpiece table I and connected to the tailstock 6 via a suitable shaft coupling. It may be combined with

In order for workers to control the machine, the machine is equipped with a device that feeds back the rotational speed of the workpiece and tool.

For example, there is a tachometer 44 on the shaft that receives the tool and the workpiece.
, 45 or the like can be connected.

It is also possible to provide a digital display instead of a tachometer.

Adjustment devices 23, 24 are arranged on the motors 14, 21, with which the speed of each motor and the braking moment, which varies with this speed or is constant, are nullified. It can be adjusted in stages.

This allows the tool and workpiece to be supported against each other by varying alternating forces during precision machining.

For example, when a tool is driven, the tool does not simply carry the workpiece, but instead is moved by the motor 2 on the side of the driving tooth.
The resistance caused by the braking force of 1 must be overcome.

As already mentioned, it may be the tool or the workpiece that is driven.

The parts that are not driven are braked.

By this and by changing the direction of rotation of the motor, two machining stages are obtained per tooth flank, ie a total of four machining stages, when performing precision machining with tooth flank play.

These processing steps are illustrated in FIGS. 2 through 5.

When the tool 3 is driven counterclockwise (arrow 25) and the workpiece is braked, as shown in FIG. It will be done.

This contact point 26 then moves along the left flank 28 of the tooth 27 in the direction of the arrow 29 from the head towards the root.

While maintaining this rotation direction, the workpiece rotates clockwise (3rd rotation direction).
When driven in accordance with the arrow 30) in the figure and the tool is braked, the first contact of the tooth 27 of the workpiece 4 is at the contact point 31 at the root of the tooth.
It will be held in

In this case, the contact point 31 moves on the right tooth flank 33 of the tooth 27 from the tooth root toward the tooth head in the direction of arrow 32.

When the direction of rotation is then changed (FIG. 4), the tool is driven again (arrow 34) and the workpiece is braked, the first contact of the tooth 27 is made at the contact point 35 on the tooth head. , this contact point is indicated by an arrow 36 on the right tooth side surface 33 toward the root of the tooth.
Move in the direction of.

Finally, while maintaining this direction of rotation, the workpiece is driven again (arrow 3γ in FIG. 5), and when the tool is braked, the first contact of the teeth 27 takes place at the contact point 38; The contact point moves along the left tooth flank 28 in the direction of arrow 39 from the tooth root towards the tooth head.

Switching the motor from "drive" to "brake" or vice versa, or from "clockwise" to "counterclockwise" (9), is of course done automatically.

For this purpose, the two motors 14 and 21 are coupled to one another via a known control device 40 in such a way that the different machining steps are carried out automatically one after the other in the aforementioned order or in any other arbitrary order.

The duration of the individual processing steps can be determined, for example, by a known counting mechanism 41.
is controlled in relation to the rotational speed of the tool.

In this case, this counting mechanism 41 sends a corresponding signal to the control device.

It is possible to slowly start the driving motor and rotate the braking motor with a constant braking moment before starting, but when the mass to be accelerated starts, both motors must be started to drive first. However, it is advantageous to switch one to braking after a predetermined period of time.

It is particularly advantageous in this case not to switch suddenly to full braking torque, but to increase the braking torque from zero to a preset maximum value in order to protect the tool.

By varying the braking moment on the workpiece, the crimp force on the flank of one of the teeth on the workpiece can be varied.

Furthermore, independently of this, it is also possible to change the absolute value of the total crimping force by changing the approach feed of the workpiece and by changing the axis spacing.

The magnitude and time interval of the approach feed can be controlled by the control device 40 via a counting mechanism 41, for example likewise in relation to the rotational speed of the tool.

The shape errors of the tooth flanks mentioned at the beginning, which are caused by machining each tooth flank in only one direction, can now be substantially avoided by the aforementioned machining steps.

Furthermore, in order to ensure as good a machining as possible, the motors 14, 21 are provided with additional resilient masses 42, 43 in order to stabilize the drive, i.e. so that the desired drive speed does not change unfavorably. You can keep it.

The present invention, which takes as an example a machine for precision machining gears that works by the plunge machining method, can be applied to all other machines for precision machining gears.

Furthermore, the machine itself can also be equipped with all the equipment necessary for its operation and the particular processing method.

For example, cooling and lubricating devices known per se or a horizontally movable table for producing an additional lateral movement between the tool and the workpiece can be provided.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a diagram showing a machine for precision machining gears according to the present invention, and FIG.
Figures 5 through 5 show the state of engagement between the tool and workpiece when contact occurs only on one side of the tooth,
Figure 2 is a diagram showing the case where the tool is driven counterclockwise;
Figure 3 is a diagram showing the case where the workpiece is driven clockwise;
FIG. 4 is a diagram showing the case where the tool is driven clockwise, and FIG. 5 is a diagram showing the case where the workpiece is driven counterclockwise. 1...Machine frame, 2...-tool holder, 3...tool, 4...workpiece, 5,
6... Tailstock, 7... Workpiece table, 8... Carriage table, 10... Shaft, 11...
...Motor, 13...Bundle, 14.
...Electric motor, 15...Gear transmission, 16,17...Spur gear set, 18,19...
...Bevel gear set, 20...Clutch, 21...
...Electric motor, 22...Clutch, 23
, 24...Adjusting device, 25...Arrow,
26...Contact point, 27...Tooth of workpiece, 28...Tooth side surface, 29...Arrow, 30...
...Arrow, 31...Contact point, 32...Arrow, 33...Tooth side surface, 34...Arrow, 35...
...Contact point, 36...Arrow, 37...
Arrow, 38...Contact point, 39...Arrow, 40...Control device, 41...Counting mechanism, 4
2.43... Resilient mass body, 44, 45... Tachometer, 50... Arrow.

Claims (1)

[Scope of Claims] 1. A precision machining machine using a gear-shaped tool by honing, cutting, or other machining methods that produce tooth side play between the tool and the workpiece, which In those types having devices for varying the pressure force between the tooth flanks in contact with each other, the direction can be reversed by accelerating or braking the tool and/or the workpiece meshing with the tool, or characterized in that both the tool and the workpiece are constructed so that they can be driven in rotation by their own drive and/or braking devices, so that the tooth flanks can be loaded with a crimping force that can vary in magnitude. , a machine that precisely processes gears. 2. Machine according to claim 1, characterized in that both drive motors (14, 21) are connected to regulating devices (23, 24) which make it possible to adjust different speeds and torques. 3. The two drive motors 14.21 are connected via a control device 40 which automatically passes through the different machining stages in a predetermined order which can be varied and at predetermined times. Machine part 4 according to claim 1 or 2, wherein bouncy mass bodies 42, 43 are disposed in the tool drive motor 14 and/or the workpiece drive motor. machine.