JPS5828051B2 - hobbing machine - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hobbing machine for cutting gears.

As shown in FIG. 8, a conventional hobbing machine of this type has an electric motor 11 and a gear transmission mechanism 1 connected to a differential gear mechanism 10.
A drive device 13 consisting of 2 is provided, and the rotation of the electric motor 11 is transmitted to the differential gear mechanism 10 via the gear transmission mechanism 12.
It is transmitted to the hob 15 via the gear transmission mechanism 14 linked to the differential gear mechanism 10, and the hob 15 cuts the gear material.

However, in the hobbing machine described above, the electric motor 11
A gear transmission mechanism 1 consisting of a large number of gears between and a hob 15
2 and 14, many troubles occurred during the gear cutting operation of the gear material due to twisting of the transmission shaft, backlash of the gear, etc.

That is, due to torsion of the transmission shaft, backlash of the gear, etc. that occur during gear cutting operation of the gear material, the force of the cutting blade of the hob 15 related to the gear material fluctuates on the hob shaft 15a furthest from the drive source, causing rotation. This causes vibration, and the cutting edge of the hob vibrates while being embedded in the gear material, causing the edge of the cutting blade to be compressed, stretched,
Chips may occur in units of 1/100 mm due to mechanical causes such as impact (in addition to this, the cause of chipping may also be due to thermal strain due to rapid changes in temperature).

) There were defects that caused early wear and damage to the tooth surface of the gear being cut.

Therefore, the number of gears that can be continuously cut by the same hob 15 is extremely limited, and it is extremely difficult to use a carbide hob made of a hard material.

In particular, carbide hobs made of high-speed steel and containing about 8 parts of cobalt were prone to chipping.

In addition, as mentioned above, if the transmission shaft is twisted during gear cutting operation, the cutting force will suddenly decrease, especially when the cutting blade of the hob 15 completes cutting a predetermined tooth of the gear material and extracts it from there. This caused the transmission axis of the transmission system to untwist, causing the tooth traces of the gear material to be cut to bend, making it impossible to manufacture high-precision gears and also making it impossible to cut large gears for modules. .

Particularly in multi-thread hobs such as 3-thread and 5-thread hobs, the cutting torque is large and the gear material is rotated quickly, so the bending of the tooth traces has been particularly pronounced in the past.

The present invention has been made to eliminate the numerous deficiencies in conventional hobbing machines as described above, and its first purpose is to arrange a hydraulic morph close to the hob, and to connect the morph axis to the hob axis. Unlike the conventional hobbing machine mentioned above, by directly connecting to the hobbing machine, there is no effect of torsion of the transmission shaft or backlash of the gears, and there is less chipping or wear of the hob's cutting edge, making it possible to use the same hob to machine a large number of gears. In addition to being able to cut gears, it is also possible to cut various gears using a carbide hob, and the tooth traces of the gear material to be cut do not bend, making it possible to manufacture high-precision gears. The object of the present invention is to provide a new hobbing machine that can also cut.

The second object of the present invention is to arrange a hydraulic motor close to the hob and directly connect its morph axis to the hob axis.
The hob drive morph can be made smaller, and the hydraulic morph absorbs the large impact that is applied to the cutting blade during gear cutting, especially when the cutting blade of the hob starts to cut into a predetermined tooth of the gear material. To provide an excellent hobbing machine that can further reduce chipping and wear of the blade.

Furthermore, a third object of the present invention is to dispose a hydraulic motor close to the hob, and to connect the morph shaft and the hob shaft with an elastic joint with a shock absorbing effect. An excellent hobbing machine in which the elastic joint together with the hydraulic morph absorbs a large impact applied to the cutting blade when the cutting blade starts cutting into a predetermined tooth of a gear material, further reducing chipping and wear of the cutting blade of the hob. Our goal is to provide the following.

A fourth object of the present invention is to arrange the table driving gear on the same hob shaft between the hob and the elastic joint, so that the rotary motion of the hydraulic morph is not directly used as a drive source for driving the table. By linking the same rotation of the hob through the elastic joint to the rotational movement of the table through the table and drive gear, there is no relative rotation between the hob and the table drive gear, and the hob's rotation relative to the gear material is eliminated. To provide an excellent hobbing machine capable of accurately cutting gears.

Hereinafter, the configuration of a hobbing machine embodying the present invention will be explained with reference to the drawings. As shown in FIG. A drive device 19 consisting of a hydraulic motor 17 and an elastic joint 18 with a shock absorbing effect is provided adjacent to the morph shaft 17a and the hob shaft 1.
5a are connected on one axis via the elastic joint 18, and the hob 15 is directly driven when the hydraulic morph 17 is driven.

On the other hand, between the elastic joint 18 and the hob 15, the hob shaft 1
A differential gear mechanism 10 is linked to the table driving gear 16 disposed at 5a via a gear transmission mechanism 14, and the differential gear mechanism 10 includes an indexing gear mechanism 20, a differential gear mechanism 21, and a differential gear mechanism 10. A transfer gear mechanism 22 is linked, and as the hob shaft 15a and the table driving gear 16 rotate together, the worm wheel W of the gear material mounting shaft is rotated via the respective gear mechanisms 20, 21, and 22. At the same time, the hob head 23 supporting the hob 15, hob@15a, etc. is moved, and the gear material is cut by the hob 15.

Next, the configuration of the drive device 19 will be explained in detail with reference to FIGS. 2 to 7.

First, FIGS. 2 and 3 show a first embodiment, in which a mounting plate 25 is fixed to the front end of the hydraulic morph 17 with an appropriate number of bolts 24,
Another mounting plate 27 is welded and fixed to the end face of the cylindrical casing 26 that is welded and fixed to the side surface of the mounting plate 25.
A joint chamber 28 is formed by the casing 26 and both singing plates 25 and 27.

A drive joint board 31 is fixed to the morph shaft 17a of the hydraulic morph 17 via a key 30 with a screw 29, and an annular groove 31a formed on the front surface of the drive joint board 31 is made of a relatively hard elastic material such as urethane rubber. A plurality of engaging members 32 having engaging protrusions 32a protruding from their outer surfaces are housed and fixed at equal intervals.

Further, a cylindrical reinforcing member 33 is embedded in the center of each engaging member 32 to prevent the engaging member 32 itself from being bent.

On the other hand, an appropriate number of bolts 34 are mounted on the outer surface of the mounting plate 2γ.
The bearing plate 35 is fixed so that the hob shaft 15a is placed upright on the same axis as the morph shaft 17a by a pair of bearings 36a and 36b.
It is rotatably supported approximately at the center of 5.

A driven joint plate 39 is fixed to the tip of the hob shaft 15a with a pair of nuts 37 via a key 38, and a ring-shaped groove 39a formed on the front surface thereof is filled with urethane rubber or the like like the aforementioned engaging member 32. A plurality of engaging members 4 are made of a relatively hard elastic material and have engaging protrusions 40a protruding from their outer surfaces.
0 are housed and fixed at equal intervals, and both of the engaging members 32
, 40 engaging protrusions 32a, 40a alternately engage with each other,
The motor shaft 17a and the hob shaft 15a are coupled so as to be shock absorbable.

Further, the above-mentioned engaging member 3 is provided at the center of the engaging member 40.
As in case 2, a cylindrical reinforcing member 41 is embedded to prevent the engaging member 40 itself from bending.

Therefore, the rotation of the hydraulic motor 17 is transmitted from the motor shaft 17a to the hob shaft 15a via the elastic joint 18, and the hob 15 attached to the tip of the hob shaft 15a is directly driven, thereby reducing rotational vibration of the hob shaft 15a. Gear cutting of gear material is possible without significant chipping or wear of the cutting blade due to the vibration.

In addition, if a large cutting force is applied to the cutting blade of the hob 15 during this gear cutting operation, especially at the time when the cutting blade of the hob 15 starts cutting into a predetermined tooth of the gear material, the hydraulic morph 1 itself and the Since the shock absorbing occurs at the engaging protrusions 32a and 40a of both engaging members 32 and 40 of the elastic joint 18, the cutting edge will not collide with the gear material and be chipped.

Furthermore, since each of the engaging members 32 and 40 is made of a relatively hard elastic material such as urethane rubber as described above, the surface engaging protrusions 32a and 40a may be slightly elastically deformed in the above case. After absorbing the impact of the hob 15, the hydraulic motor 17 is connected to the hob 1 without irregular twisting or loss of power between the motor shaft 17a and the hob shaft 15a.
5, a large amount of power is accurately transmitted, and highly accurate gear cutting is performed.

That is, the elastic joint 18 that connects the hob shaft 15a and the motor shaft 17a has such a property that it immediately exhibits resistance close to that of a rigid body after absorbing an impactful load through slight elastic deformation at the beginning of gear cutting. is desirable.

This is because if the elastic deformation is too large, it will be the same as if the hob shaft 15a is twisted to a large extent, causing adverse effects such as creating triangular notches on the tooth surface.

In order to have such slight elastic deformation and strong resistance, it is necessary to increase the hardness of the rubber used and to prevent volume changes as much as possible, as in the second and third embodiments described later.

Furthermore, in the hobbing machine of the present invention, fluctuations in cutting force are absorbed by the elastic joint and are not applied directly to the transmission shaft or transmission gear, so there is less elastic deformation due to the cutting force of the hobbing machine, and noise is also reduced.

Therefore, even with a hobbing machine of the same output, it is possible to cut gears of large modules with high precision.

Next, a second embodiment of the first drive device 19 shown in FIGS. 4 and 5 will be explained. The elastic joint 18 of this embodiment is attached to the front surface of the drive joint board 31 fixed to the tip of the motor shaft 17a. A plurality of connecting rods 42 are projected on the same circumference at regular intervals, and a plurality of accommodation holes corresponding to the connecting rods 42 are provided on the front surface of the driven joint plate 39 fixed to the tip of the hob shaft 15a. 43 is formed.

Inside these accommodation holes 43, cylindrical buffer members 44 made of a relatively hard elastic material such as urethane rubber are inserted through sleeves 45, similar to the engaging members 32 and 40 in the first embodiment described above. The buffer members 4
Both ends of the receiving hole 43 are closed by closing members 46 a and 46 b screwed into both ends of the receiving hole 43, respectively.

The connecting rod 42 is connected to the sleeve 4 in the buffer member 44.
5, respectively, and the motor shaft 17a and the hob shaft 15a
and are connected to enable shock absorption.

Therefore, the variation in the cutting force applied to the cutting edge of the hob 15 during gear cutting operation of the gear material is absorbed by the buffer member 44, as in the first embodiment described above, and chipping of the cutting edge is prevented. be done.

Further, in this embodiment, as described above, both ends of each buffer member 44 are closed by the closing members 46 a t 46 b, so that the elastic deformation rate of the buffer member 44 is equal to the insertion error of the buffer member 44. The cushioning member 44 is slightly elastically deformed due to the slight gap between the
After absorbing the impact of the hob 15, it becomes a rigid body, and the hydraulic motor 17 can be operated without irregular twisting or power loss between the motor shaft 17a and the hob shaft 15a.
A large amount of power is accurately transmitted from the hob 15 to the hob 15, and the high-purity grain is cut.

Next, a third embodiment of the drive device 19 shown in FIGS. 6 and 7 will be described.
A pair of connecting pieces 47 are provided in an annular groove 31a on the front surface of the drive joint board 31 fixed to the tip of the motor shaft 17a, and a pair of connecting pieces 47 are provided to protrude toward the center, and the hob shaft 15 projects into the annular groove 31a.
A pair of connecting pieces 48 are provided at the tips of the connecting pieces 47 and 48 to protrude outward, and in the annular groove 31a between the connecting pieces 47 and 48, the engaging members 32 and 40 in the first embodiment described above and the second connecting pieces 48 are provided. Similar to the buffer member 44 in the embodiment, a plurality of buffer members 49 are made of a relatively hard elastic material such as urethane rubber.
are fitted, and the outer surfaces of the buffer members 49 are closed by a closing member 50 screwed and fixed to the drive joint disk 31.

Therefore, in this embodiment, as in the case of the above-mentioned first and second embodiments, the hob 1 is
Fluctuations in the cutting force applied to the cutting edge 5 are absorbed by the buffer member 49, thereby preventing chipping of the cutting edge.

Also, in this embodiment, the buffer member 49 is fitted into the annular groove 31a of the drive joint plate 31 in a closed state, as in the case of the second embodiment described above, so that the buffer member 49 is slightly After being elastically deformed and absorbing the impact of the hob 15, it becomes a rigid body and can be moved from the hydraulic motor 17 without irregular torsion or loss of power between the motor shaft 17a and the hob shaft 15a. A large amount of power is accurately transmitted to the hob 15, and highly accurate gear cutting is performed.

In this way, the present invention disposes the hydraulic motor close to the hob and connects the motor shaft directly to the hob shaft, so that the power of the motor is transmitted to the hob via a gear transmission mechanism consisting of a large number of gears. Unlike conventional hobbing machines, there is no effect of twisting of the transmission shaft or backlash of gears.
Chips and wear on the cutting edge of the hob are reduced, and a large number of gears can be cut with the same hob, and a carbide hob can be used to cut a variety of gears, and the teeth of the gear material being cut are This has the great effect of not only making it possible to manufacture high-precision gears without bending the threads, but also being able to cut gears with large modules.

In addition, the present invention places a hydraulic motor close to the hob and connects the motor shaft directly to the hob shaft, thereby eliminating power loss and making it possible to downsize the hob drive motor. The hydraulic motor absorbs a large impact on the cutting blade at the time when the cutting blade begins to cut into a predetermined tooth of the gear material, thereby producing an excellent effect of further reducing chipping and wear of the cutting blade of the hob.

Furthermore, the present invention places a hydraulic motor in close proximity to the hob;
By connecting the motor shaft and the hob shaft with an elastic joint that has a shock absorbing effect, a large impact is applied to the cutting blade during gear cutting, especially when the cutting blade of the hob begins to cut into a predetermined tooth of the gear material. This is absorbed by the elastic joint together with the hydraulic motor, resulting in a significant effect of further reducing chipping and wear of the cutting edge of the hob.

In particular, the present invention arranges the hob and the table drive gear on the same hob shaft, and without using the rotary motion of the hydraulic motor as a drive source for directly driving the table, the hob and the table drive gear are connected to the same hob through an elastic joint. By linking the rotation of the hob with the rotation of the table via the table drive gear, there is no relative rotation between the hob and the table drive, which has the great effect of accurately cutting the hob against the gear material in a row. .

Note that if the table drive gear is disposed between the hydraulic motor and the elastic joint, relative rotation will occur between the hob and the table 1 drive gear, making it impossible to accurately cut gears on the gear material of the hob. It disappears.

[Brief explanation of the drawing]

FIG. 1 is a road diagram showing the power transmission system of the hobbing machine of the present invention;
FIG. 2 is a longitudinal sectional view showing a first embodiment of the first driving device of the present invention, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, and FIG.
7 is a longitudinal sectional view showing a second embodiment of the drive device, FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, and FIG. Figure 7 is 7- in Figure 6.
A sectional view taken along line 7 and FIG. 8 is a road body diagram showing a conventional hobbing machine.

Claims (1)

[Claims] 1 Hydraulic motor 17 and appropriate gear linkage mechanism 14°10
A table driving gear 16 linked to the hob head 23 and the mounting shaft of the gear material via the hob 15 and the hob 15 are sequentially disposed close to each other on the same axis, and the hydraulic motor 17 and the table driving gear 16 Between the hob shaft 15a and the motor shaft 17a, the cutting edge of the hob 15 softly contacts the gear material, so that the impact is absorbed by slight elastic deformation against the impact load, and the impact is absorbed. The hobbing machine is characterized in that the hobbing machine is connected by an elastic joint 18 that immediately exhibits resistance close to that of a rigid body and has a shock absorbing effect that slowly returns to its original state when the load is removed.