JPH04275823A - Drive device of hobbing machine - Google Patents

Abstract

PURPOSE:To remarkably decrease generation of advance/delay in rotation of a hob arbor due to load variation when a work is machined by a hob, by separating a hob driving motor structurally from a hob saddle vertical feed mechanism and a work table indexing mechanism, and installing the motor at a part of the hob saddle within the column. CONSTITUTION:A hob saddle 4 is installed on a column 2 mounted upright at one side of a bed 1, wherein the hob saddle 4 shall be capable of sliding in vertical direction with the aid of a vertical feed mechanism 3. A work table 6 is installed on the other side of the bed 1 in such a way as rotatable through an indexing mechanism 5. Further a hob driving motor 20 is installed at a part of the hob saddle 4 within the column 2 while separated structurally from the vertical feed mechanism 3 and the work table indexing mechanism 5, and thereby generation of advance/delay in rotation of a hob 12 due to varying machining load will be decreased remarkably.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a hobbing machine that cuts a workpiece (gear material) with a hob (gear cutting tool) to produce spur gears, helical gears, etc.

0002

[Prior Art] As shown in Fig. 2, a hobbing machine is generally mounted on a column (2) erected on one side of a bed (1) so as to be slidable in the vertical direction via a vertical feed mechanism (3). A work table (6) rotatably mounted on the other side of the bed (1) via an indexing mechanism (5), and an angle changer on the front side of the hob saddle (4). mechanism(
The hob head (8) is attached so that its angle can be changed through the hob head (8).
) and the column (2) supported at both ends by the hob head (8).
A hob arbor (11) that is rotatably driven from a main shaft (9) inside via a hob drive mechanism (10), a hob (12) attached to this hob arbor (11), and a work arbor ( 13) The workpiece (
14) and a slide head (15) that supports the upper end of the work arbor (13).

[0003] The vertical feed mechanism (3), indexing mechanism (5), and hob drive mechanism (10) must be driven in a predetermined relationship in order to cut the desired gear, so they must be driven by a common drive motor. (16) and are mutually interlocked via the main shaft (9).

Recently, NC hobbing machines have been used, and in this case, as shown in FIG. 3, the indexing mechanism (5) of the work table (6) is driven by another servo motor (17). There are some things. In this case, other parts are the same as in FIG.

[0005] In either case, the hob drive mechanism (10)
As shown in Fig. 4, two relay shafts (10a) (10
b) and bevel gears (10c) to (10f) and gears (10g
) (10h). In this case, the bevel gear (10c) on the main shaft (9) is attached to the hob saddle (
4), and moves vertically together with the hob saddle (4);
The main shaft (9) has a spline shaft portion formed in a portion corresponding to the vertical movement range of the hob saddle (4), and a spline slot corresponding to this portion is formed in the bevel gear (10c), and these are spline-engaged. , with respect to the main shaft (9), the bevel gear (1
0c) can be slid in the axial direction and rotated as one unit.

[0006] The angle changing mechanism (7) also allows the hob head (8) to rotate about a half turn left and right about the relay shaft (10a) with respect to the hob saddle (4), Warm (7b) by forward/reverse motor (7a)
, a worm wheel (7c), and gears (7d) and (7e) to rotate the hob head (8). In this case, the gear (7e) is rotatably installed on the relay shaft (10a) and is fixed to the hob head (8) so as to rotate together with the hob head (8).

When cutting a spur gear using the hobbing machine, as shown in FIG. 5, the hob (12) is rotated and moved downward to form tooth grooves (14a) on the outer periphery of the workpiece (14). Cutting and forming. The tooth grooves (14a) are formed for one tooth or a plurality of teeth, and the workpiece (14) is indexed and rotated correspondingly. In actual machining, the cutting edge of the hob (12) is formed in a helical shape to set the relief angle even in the case of a spur gear, and normally the cutting edge of the hob (12) is Work (14)
The gears are connected so as to rotate by one-th of the number of teeth.

[0008] Furthermore, when cutting a helical gear,
The angle changing mechanism (7) rotates the hob head (8) at a predetermined angle to tilt the axis of the hob arbor (11) so as to correspond to the teeth of the helical gear, and in this state, the workpiece (
14) is also given a rotation corresponding to the lead angle of the tooth trace of the helical gear.

[0009]

A conventional hobbing machine extracts driving force from a main shaft (9) installed in a column (2) as a drive source for a hob drive mechanism (10). In either case of FIGS. 2 and 3, this main shaft (9) requires a length longer than the vertical movement stroke of the hob saddle (4), so it is likely to cause torsion. In particular, when observing the load state during cutting of the workpiece (14), as shown in Fig. 5, the cutting load gradually increases from the upper end of the tooth groove (14a) in the tooth width direction (vertical direction in the figure) to the center position. , gradually decreases from the center to the bottom. Moreover, the hob (12)
cutting is also interrupted cutting, and since the cutting load fluctuates from the start of cutting to the end,
The amount of torsion in 9) changes depending on the cutting position of the workpiece (14), and this causes a delay in the rotation of the hob (12), which is driven from the main shaft (9) via the hob drive mechanism (10). do.

[0010] If a delay occurs in the rotation of the hob (12), the shape of the tooth groove (14a) of the workpiece (14) will not be as intended, resulting in a reduction in machining accuracy. For example, when cutting a spur gear, disadvantages such as inclined tooth traces and curved tooth groove bottoms occur.

The present invention is intended to solve the above-mentioned drawbacks of conventional hobbing machines. However, in order to solve the above drawbacks, it is also possible to directly connect the drive motor and the speed reduction mechanism to one end of the hob arbor (11), as shown in FIG. The sides become longer, and when machining helical gears, not only do more areas interfere with the work table (6), but the weight balance of the hob head (8) is also poor, causing problems with the vertical feed mechanism (3) and slide guide of the hob saddle (4). There are problems such as uneven load being applied.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hobbing machine drive device that can overcome the above-mentioned drawbacks.

[0013]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a hob saddle mounted on a column erected on one side of a bed so as to be slidable in the vertical direction via a vertical feed mechanism, and a bed. In a hobbing machine equipped with a work table rotatably mounted on the other side via an indexing mechanism, the hob drive motor is connected to the vertical feed mechanism of the hob saddle and the indexing mechanism of the work table. It is separated and installed in a part of the hob saddle within the column.

[0014]

[Operation] Since there is no long shaft between the hob drive motor and the hob arbor, it is possible to significantly reduce the occurrence of advance and lag in the rotation of the hob due to cutting load fluctuations.

Furthermore, since the hob driving motor is located within the column, there is no interference with the work table even when machining a helical gear. Furthermore, the hob head on the front side and the hob drive motor on the rear side are weight-balanced with respect to the slide guide surface of the hob saddle, and adverse effects caused by unbalanced loads can be prevented.

[0016]

[Example] FIG. 1 is a schematic front view of the device of the present invention, and (
1) is the bed, (2) is the column, (3) is the vertical feed mechanism, (4) is the hob saddle, (5) is the indexing mechanism, (6) is the work table, (7) is the angle changing mechanism, (8) ) is the hob head, (10) is the hob drive mechanism, (11) is the hob arbor, (12) is the hob, (13) is the work arbor, (1
4) is a workpiece, and (15) is a slide head, which are the same as those of a conventional hobbing machine, so a detailed explanation thereof will be omitted. However, the vertical feed mechanism (3) is operated by the first servo motor (
18), and the indexing mechanism (5) is driven by a second servo motor (19). The hob drive mechanism (10) is driven by a hob drive motor (20). Each of these motors (18) (19) (20)
are driven in relation to each other by an NC control device (not shown) to suit the machining conditions of the target gear.

The hob drive motor (20) is a part of the hob saddle (4) and is connected to the hob head (8) with respect to the vertical slide guide surface (21) of the hob saddle (4) formed on the column (2). ) on the opposite side of the column (
2) Install inside. This hob drive motor (2
0) drives the hob arbor (11) via the hob drive mechanism (10) shown in FIG.

The apparatus of the present invention has the above-mentioned structure, and since there is no long shaft in the drive system of the hob (12) as in the conventional case, the hob (12) is able to withstand load fluctuations during cutting of the workpiece (14). 12) The occurrence of a delay in the rotation can be significantly reduced.

[0019]

According to the present invention, it is possible to significantly reduce the appearance of advance and lag in the rotation of the hob arbor due to load fluctuations during cutting of a workpiece by the hob, thereby improving the machining accuracy of gears. Moreover, even when processing a helical gear, interference with the work table can be prevented, and furthermore, the hob head and the hob drive motor are weight-balanced, and adverse effects caused by unbalanced loads can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of an NC hobbing machine of the present invention.

FIG. 2 is a schematic front view showing an example of a conventional hobbing machine.

FIG. 3 is a schematic front view showing an example of a conventional NC hobbing machine.

FIG. 4 is a schematic perspective view of a hob drive mechanism.

FIG. 5 is an explanatory diagram of a gear cutting state using a hob.

[Explanation of symbols]

1 Bed 2 Column 3 Vertical feed mechanism 4 Hob saddle 5 Indexing mechanism 6 Work table 7 Angle change mechanism 8 Hob head 10 Hob drive mechanism 11 Hob arbor 12 Hob 13 Work Arbor 14 Work 15 Slide head 20 Hob drive motor

Claims (1)

[Claims] [Claim 1] A hob saddle mounted on a column erected on one side of the bed so as to be slidable in the vertical direction via a vertical feed mechanism, and a hob saddle mounted on the other side of the bed so as to be rotatable via an indexing mechanism. In a hobbing machine equipped with an attached work table, the hob drive motor is mechanically separated from the hob saddle vertical feed mechanism and the work table indexing mechanism and is installed in a part of the hob saddle within the column. A hobbing machine drive device characterized by: