JPH02205288A - Laser beam processing head - Google Patents

Abstract

PURPOSE:To prevent the rotation of a second hollow shaft due to the rotation of a first hollow shaft in a simple linking structure, and to individually and simultaneously control the respective hollow shafts by attaching the respective driving means of the first and second hollow shafts to be the two rotation shafts of a laser beam processing head to a head main body on a base side. CONSTITUTION:A rotation transmitting tube 20 is freely rotatably provided so as to be concentrical with a first hollow shaft 2, and a second hollow shaft 4 is rotated through the rotation transmitting tube. A harmonic drive decelerator 19 is provided in second driving means, and the first hollow shaft 2 is rotated by a first driving means 16, simultaneously the rotation is transmitted to the harmonic drive decelerator on a second driving means 17 side, and the rotation transmitting tube is rotated as well at the same rotation as the first hollow shaft. Thus the relative rotation between a first rotation bracket 3 and the second hollow shaft 4 due to the first hollow shaft rotation is prevented, and since the second hollow shaft 4 can be independently rotation-driven as well by the second driving means 17, the two shafts can be easily controlled without a complicated correcting means.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser processing head, and particularly to a device for driving two rotating axes at the tip of an articulated laser processing head.

[Prior Art] Conventionally, this type of multi-jointed laser processing head has not only controlled the three axes of X, Y, and Z, but also maintained the irradiation optical axis of the laser beam in the normal direction, for example, to the work surface. As a result, an appropriate machining state can be obtained, and therefore, laser machining of a three-dimensional workpiece is performed while changing the attitude of the laser machining nozzle according to the surface shape of the workpiece. As a mechanism for changing the posture of the nozzle, a first rotating bracket is rotatably controlled with respect to the head body around a first rotating axis, and the first rotating bracket is rotatably supported by the first rotating bracket, and the first rotating bracket is rotatably supported by the first rotating bracket. and a second rotation bracket whose rotation is controlled around a second rotation axis in a different direction, and the rotation of the two axes is controlled by respective drive motors based on respective control signals.

Generally, the first axis drive motor is provided in the head body,
The rotational drive is transmitted to the first shaft via gears, etc., but the rotational drive is transmitted to the second shaft.
The shaft drive motor was conventionally mounted on the first rotating bracket.

However, if such a rotating part is provided with a drive motor, the head itself becomes heavy and the tip end becomes large. Furthermore, the wiring structure is intricately intertwined with the head tip near the processing position, and in order to allow rotational movement of around 360° of each of the first rotation axis and the second rotation axis, it is necessary to
A long cord is required, and therefore, during movement, it is inevitable for the cord to twist, get wrapped around other mechanisms, and interfere with the workpiece, and the appearance cannot be kept clean.

[Problems to be Solved by the Invention] For this reason, the drive motor for the second shaft is provided on the head body side in the same way as the drive motor for the first shaft, and the drive motor for the second shaft is connected from the inside or outside of the first shaft via a transmission means. If you drive the rotation,
The above wiring and appearance problems are resolved. However, if the first shaft rotates by simply connecting each motor and each shaft, relative rotation will occur between the first main shaft and the transmission means, and the second shaft will also rotate relative to the first shaft. As a result, the rotational movements of both axes become related to each other. Therefore, in order to drive and control each axis independently with respect to the absolute coordinates of the ground, etc., by applying rotation in the opposite direction to the direction in which the second axis rotates together with the rotational movement of the first axis, It may be configured such that the rotation of one axis cancels out the rotation of the other axis.

For this reason, in conventional laser processing heads, solutions using various differential gear mechanisms and compensating methods using calculation control (software) have been considered. For example, if you try to implement a cancellation method using software, not only will high-speed calculation processing be required, but the acceleration/deceleration characteristics of both drive systems will also affect the stopping state of the second axis, making control extremely difficult. It becomes expensive. Therefore, in both cases, the drive system, control system, etc. are complicated, and they are not suitable means for passing light through a rotating shaft such as a laser processing robot and controlling the movement of a processing head for high-precision processing.

In view of the above, the present invention has provided that the drive means for the first hollow shaft and the second hollow shaft, which are the two rotational axes of the laser processing head, are both attached to the head body on the base side, and the first hollow shaft is connected using a simple connection structure. It is an object of the present invention to provide a laser processing head that prevents rotational movement of the second hollow shaft due to rotation, and that enables individual and simultaneous control of each hollow shaft using its own driving means.

[Means for Solving the Problems] That is, the present invention rotatably supports a first rotation bracket that is integral with the first hollow shaft via the first hollow shaft in the head body, and °2nd on bracket
In a laser processing head that rotatably supports a second rotary bracket that is integral with the second hollow shaft via a hollow shaft, and supports a lens holder at the tip of the second rotary bracket, the first hollow shaft is A first driving means for rotationally driving the second hollow shaft and a second driving means for rotationally driving the second hollow shaft are respectively attached to the head body, and the first hollow shaft is a rotation transmitting cylinder connected to the second hollow shaft so as to be rotatable. The head body is rotatably supported concentrically, a first working wheel is integrally provided on the first hollow shaft, a second working wheel is integrally provided on the rotation transmission cylinder, and a harmonic is provided on the output shaft of the second drive means. A web generator of a drive (registered trademark, hereinafter the same) reducer is connected, and this harmonic drive reducer includes the web generator, a flex spline rotatably provided on the outer periphery of the web generator, and a flex spline inside the flex spline. It consists of a first circular spline that is tooth-coupled and a second circular spline that has a different number of teeth from the first circular spline and that is internally coupled to the flex spline, and an interlocking ring is integrally provided on the first circular spline, and the The first circular spline is connected to the first working wheel so that rotation can be transmitted thereto, and a transmission wheel is integrally provided to the second circular spline to be connected to the second working wheel so that rotation can be transmitted, and the web generator is fixed. is on the input side and the second circular spline is on the output side, and when the gear ratio of the harmonic drive reducer is R, the number of teeth of the first working wheel Z3. By setting the number of teeth so that the relationship between the number of teeth of the driving wheel, 72, the number of teeth of the transmission wheel, 23, and the number of teeth of the second operating wheel, satisfies the following formula, The rotation of one hollow cylinder is configured to transmit the same rotation to a rotation transmission cylinder via a first working wheel, an interlocking wheel, a harmonic drive reducer, a transmission wheel, and a second working wheel.

[Example] Hereinafter, specific embodiments of the present invention will be described based on the drawings.

In FIG. 1, the head body 1 of the laser processing head is
Based on a predetermined Canadian program, X, Y, Z (not shown)
The feed is controlled in three axial directions. Further, the head main body 1 holds a processing head 7 that includes a first hollow shaft 2, a first rotation bracket 3, a second hollow shaft 4, a second rotation bracket 5, and a lens holder 6.

The first hollow shaft 2 has upper and lower bearings 8.8 with respect to the head body 1.
is rotatably and freely supported around the first rotational axis A through the
The inside is formed hollow so that laser light incident from above the head body 1 can pass therethrough.

The first rotary bracket 3 is hollow and has a predetermined shape, for example, a 7-shape, and its upper end portion is integrally fixed to the lower end portion of the first hollow shaft 2 by a screw (not shown).

The second hollow shaft 4 is rotatably supported at the tip of the first rotating bracket 3 via a bearing 9.9 around a second rotating shaft B, and has a hollow interior so that a laser beam can pass therethrough. ing.

The second rotary bracket 5 is formed hollow in a predetermined V-shape, for example, and is integrally fixed at one end to the lower end portion of the second hollow shaft 4 by a screw (not shown). Furthermore, a lens holder 6 is held at the other end of the second rotating bracket 5.

This lens holder 6 holds a condensing lens 10 inside and a nozzle 11 at its tip, and these condensing means irradiate laser light toward the intersection F between the first rotation axis A and the second rotation axis B. It looks like this. That is, it has a -point-oriented head structure.

A reflecting mirror 12 located below the first hollow shaft 2 is fixed to the first rotating bracket 3 . This reflecting mirror 12 is attached at an inclination angle of, for example, 45° with respect to the first axis of rotation A. Also, the second hollow shaft 4 of the first rotating bracket 3
A reflecting mirror 13 is located on the incident side of the laser beam.
is fixed opposite the reflecting mirror 12.

Further, a reflecting mirror 14 is fixed to the second rotating bracket 5 at a location on the side where the laser beam from the second hollow shaft 4 is irradiated at an inclination angle of, for example, 45° with respect to the optical axis of the laser beam, and A reflecting mirror 15 is fixed at a location on the incident side to the condenser lens 10 so as to face the reflecting mirror 14 .

Note that FIG. 1 shows a case where the first rotating bracket 3 and the second rotating bracket 5 are on the same plane, and the center uIC of the condensing lens 10 and the nozzle 11 is
It coincides with axis A.

In the case of this processing head 7, the laser beam enters from above the first hollow shaft 2 along the first axis of rotation A, is reflected by the reflecting mirror 12, and proceeds to the reflecting mirror 13 side of the first rotating bracket 3. , is reflected by this reflecting mirror 13 and travels along the second axis of rotation B. Then, on this second axis of rotation B, it is guided to a reflecting mirror 14 attached to the second rotating bracket 5, is reflected by this reflecting mirror 14, advances to the reflecting mirror 15 side, and is further focused by this reflecting mirror 15. The light is guided by an optical lens 10 and irradiated from a nozzle 11 toward a processing point F.

That is, according to this processing head 7, even if the direction of the irradiation surface of the workpiece changes, the first rotation bracket 3 and the second rotation bracket 5 can be rotated along the first rotation axis A and the rotation second axis B, respectively.
The irradiation point F does not move by simply changing the attitude of the nozzle 11 by rotating around it.

Next, the rotational drive structure of the first hollow shaft 2 and the second hollow shaft 4 will be explained.

The head body 1 includes a first drive motor 16 as a first drive means for rotationally driving the first hollow shaft 2 and a second drive motor 16 as a second drive means for rotationally driving the second hollow shaft 4. A drive motor 17 is arranged in parallel with the first hollow shaft 2, with motor shafts 16a and 17a facing upward, respectively. A harmonic drive reducer 19, which will be described later, is attached to the second drive motor 17.

On the other hand, a hollow rotation transmission cylinder 20 is rotatably supported on the inner periphery of the first hollow shaft 2 concentrically with the first hollow shaft 2 via bearings 21.21, and the lower end of the rotation transmission cylinder 20 is has a bevel gear 23 integrally inside the first rotating bracket 3. Further, within the first rotation bracket 2, a hollow connecting cylinder 24 is rotatably supported between the rotation transmitting cylinder 20 and the second hollow shaft 4 via bearings 25.25,
Both ends of this connecting cylinder 24 are integrally provided with bevel gears 26 and 27, the -m bevel gear 26 meshes with the bevel gear 23 of the rotation transmission cylinder 20, and the bevel gear 27 at the other end is integrally connected to the second hollow shaft 4. It meshes with a bevel gear 28 formed in .

Furthermore, during the first rotation, inside the bracket 3, each reflector 12
．． 13, the rotation transmission cylinder 20 and the connection cylinder 24
The first sealing member 50 forms the optical path of the laser beam between these members.
, a second seal member 51 is provided between the connecting tube 24 and the second hollow shaft 4 to form an optical path of the laser beam. Each of the seal members 50 and 51 is connected to the rotation transmission cylinder 2.
0, the connecting cylinder 24 is loosely fitted to the second hollow shaft 4, and the reflecting mirror 12.
It has a sealing effect to protect 13.

First and second operating gears 2 as first and second operating wheels are provided at the upper ends of the first hollow shaft 2 and the rotation transmission cylinder 20, respectively.
9.30 are provided concentrically and integrally.

The first drive motor 16 is, for example, a pulse motor, and a drive gear 42 is fixed to the motor shaft 16a. The drive gear 42 has its shaft rotatably supported by a support tube 43 integrally provided with the head body 1, and meshes with the first operating gear 29 of the first hollow tube 2.

By the way, as shown in FIGS. 2 and 3, the harmonic drive reducer 19 has a flexible cylindrical flex spline inside the first and second circular splines 36 and 32, which have different numbers of teeth. 34 are engaged with each other, and an elliptical web generator 40 is fitted therein via a flexible ring bearing 38.

The shaft 41a of the web generator 40 in this harmonic drive reducer 19 is fixed to the motor shaft 17a of the second drive motor 17, the first circular spline 36 is fixed to an interlocking gear 45 as an interlocking wheel, and the second
The circular spline 32 is a transmission gear 4 as a transmission wheel.
It is fixed at 4.

Furthermore, both gears 44 and 45 are rotatably supported by support tubes 46 and 47 that are provided integrally with the head body 1, respectively, and are provided concentrically with the shaft 41a of the web generator 40.

The interlocking gear 45 meshes with the first operating gear 29, and the transmission gear 44 meshes with the second operating gear 30.

That is, a bearing 38 is provided on the outer periphery of the elliptical web generator 40 that is integrated with the motor shaft 17a, and this bearing 38 is movable while following the rotation of the elliptical web generator 40 in the radial direction. ing. The outer circumference of this bearing 38 holds the inner circumference of the cylindrical flexspline 34. The flexspline 34 is flexible and has external teeth on its outer periphery.

The flexspline 34 can be easily deformed as the bearing 38 deforms and moves in the radial direction. First and second circular splines 36 and 32 each having internal teeth along the circumference of a perfect circle are provided at the outer peripheral positions of the external teeth of the flexspline 34. These internal teeth are
They mesh with the external teeth of the flexspline 34 in the long axis direction, but are separated from each other in the short axis direction. Among these, the internal teeth of the second circular spline 32 have one or two more teeth than the external teeth of the flex spline 34, and they mesh in the long axis direction, but in the short axis direction, they mesh with each other in the short axis direction. It doesn't mesh well. - The number of internal teeth of the force cylinder 1 circular spline 36 is equal to the external teeth of the flex spline 34, so the circular spline 36 and the flex spline 34 do not rotate relative to each other.

Now, the deceleration by the harmonic drive reducer 19 is as follows.
It is done as follows.

First, when the first drive motor 16 is in a stopped state, the first operating gear 29 is stopped, so the interlocking gear 45 is stopped, and the first circular spline 36, which is integrated with the interlocking gear 45, is stopped. The flexspline 34, which has external teeth that mesh with the flexspline 34, is also stopped.

When the second drive motor 17 rotates, the flexspline 3
This meshing between the external teeth in the long sleeve direction of 4 and the internal teeth of the second circular spline 32 moves, and the second circular spline 3
2 rotates in the same direction by the difference in the number of internal teeth and external teeth, for example, by one tooth or two teeth per rotation of the web generator 40, and as a result, the second circular spline 32 and the transmission gear 44 Gives deceleration rotation.

Furthermore, when the first drive motor 16 is rotated with the second drive motor 17 stopped and the web generator 40 stopped, the rotation of the motor shaft 16a rotates the first operating gear 29 via the drive gear 42. The interlocking gear 45 and the flex spline 34, which rotates integrally with the first circular spline 36, are rotated. The rotation of the second circular spline 32 in the same direction is delayed by the difference in the number of internal teeth and external teeth, for example, by one or two teeth, with respect to one rotation of the flexspline 34, and as a result, A decelerated rotation is applied to the second circular spline 32 and the transmission gear 44.

Here, the number of teeth of each gear 29, 45, 44, 30 is the number of teeth of the first gear when the second A moving motor 17 is stopped.
The rotation of the first actuating gear 29 due to the rotation of the drive motor 16 and the rotation of the second actuating gear 30 interlocked therewith are set so that the direction and amount of rotation are the same.

That is, as shown in FIG.
is fixed, the first circular spline 36 is on the input side, and the second circular spline 32 is on the output side, and the gear ratio of the harmonic drive reducer 19 is R,
The number of teeth of the first working gear 29 is Zl, the number of teeth of the interlocking gear 45 is Z2, the number of teeth of the transmission gear 44 is Z3, and the number of teeth of the second working gear 3 is
If the number of teeth at 0 is Z4, the rotation of the second working gear 30 when the first working gear 29 rotates once is IX(Zl/Z2)XRX(Z3/Z4), that is, the second working gear 30 also rotates as follows. To make one rotation, the number of teeth should be set to satisfy the following formula (% formula %).

Here, R is Number of teeth of second circular spline 32 It can be expressed as

Furthermore, detection means 48 and 49 for detecting rotational limits such as limit switches are provided at the upper ends of each of the drive gear 42 and the transmission gear 44, respectively, and the first hollow shaft 2 and the second
Each of the 40 rotations of the hollow shaft is rotated at a predetermined angle (e.g. 360°
).

The processing head 7 operates as follows.

First, when the first drive motor 16 rotates in response to a signal from a control device or the like, the rotation of the motor shaft 16 a rotates the first hollow shaft 2 via the drive gear 42 . As a result, the first rotation bracket 3 rotates by a predetermined angle about the first rotation axis A.

At this time, if the rotation 6 transmission cylinder 20 remains stopped, when the first rotation bracket 3 rotates, the bevel gear 26 engages with the bevel gear 23 due to revolution, rotates, and drives the second hollow shaft 4. Therefore, the second rotating bracket 5 is affected by the rotational movement of the first rotating bracket 3, causing unnecessary rotation.

However, in the structure of the present invention, the second drive motor 17
When is stopped, the rotation transmission cylinder 20 rotates by the same amount as the rotation of the first hollow shaft 2 rotated by the first drive motor 16, so there is no relative rotation between the bevel gears 23 and 26.
The second hollow shaft 4 will maintain this rotational position even if it does not rotate relative to the first rotation bracket 3.

That is, assuming that the second drive motor 17 is stopped, the rotation of the first hollow shaft 2 by the first drive motor 16 is transmitted to the interlocking gear 45 via the first operating gear 29 that is integrated therewith.
As the first circular spline 86 is rotated in the opposite direction, the rotation in the opposite direction is similarly transmitted to the flexspline 34, so that the second circular spline 32 meshing therewith and the transmission gear 44 fixed thereto are also rotated. It rotates in the opposite direction, causing the first operating gear 30 to further rotate in the opposite direction. In other words, the second operating gear 30 is rotated by the same amount and in the same direction as the first operating gear 29 based on the tooth number ratio of each gear described above.

Therefore, when the first hollow shaft 2 rotates, the rotation transmission cylinder 20 integrated with the second operating gear 30 rotates in the same direction and by the same amount of rotation, so the bevel gear 26 does not rotate. In this way, when the first hollow shaft 2 rotates, the rotation transmitting cylinder 20 rotates in the same direction by the same amount of rotation, and when the first hollow shaft 2 rotates, the rotation transmitting cylinder 20 rotates in the same direction and by the same amount of rotation.
It works to prevent unnecessary rotation from being applied to the rotating bracket 5.

Next, the second rotating bracket 50 is rotated by starting the second drive motor 17 in response to a signal from the control device, etc. At this time, the rotation of the motor shaft 17a of the second drive motor 17 is transmitted to the web generator 40. Here, assuming that the rotation of the flexspline 34 remains stopped, the rotation of the web generator 400 is transmitted to the second circular spline 32 and the transmission gear 44 under a predetermined large reduction ratio. The rotation of the transmission gear 44 is transmitted to the rotation transmission cylinder 20 by the second operating gear 30.

Here, the rotation of the rotation transmission cylinder 20 is controlled by bevel gears 23 and 26.
The connecting cylinder 24 is rotated by the bevel gear 27.
2B to the second hollow shaft 4, the second rotation bracket 5 rotates by a predetermined angle about the second rotation axis B.

At this time, the first rotating bracket 3 is not affected by the rotation of the second rotating bracket 5.

In the above operation explanation, one of the two motors 16.17 is stopped, but in actual operation, the two motors 16.1
7 may of course rotate at the same time.

In this way, regarding the rotation of the first drive motor 16, the first
The rotation is transmitted to both the hollow shaft 2 and the rotation transmission cylinder 20, and the rotation of the second drive motor 17 is transmitted only to the rotation transmission cylinder 20 without being transmitted to the first hollow shaft 2.

In this way, the first hollow shaft 2 is independently driven to rotate by the first drive motor 16, and the second hollow shaft 4 is independently driven to rotate by the second drive motor 17.

In the above embodiment, the first working wheel, the second working wheel, the interlocking wheel, and the transmission wheel are gears 29, 30, 45, 44, respectively.
However, the configuration is not limited to this, and the rotation can be transmitted by using a timing belt or chain transmission, for example, as a toothed boob.

Further, the harmonic drive reducer is not limited to the one shown in the embodiment, but it is also possible to adopt a harmonic drive reducer with a different output form, for example, by reversing the number of teeth of the first circular spline 36 and the second circular spline 32. . [Effects of the Invention] According to the present invention, the first hollow shaft and the second hollow shaft, which serve as the respective rotation axes of the first rotation bracket and the second rotation bracket rotatably supported by the first rotation bracket, are respectively A first driving means and a second driving means for driving,
By providing it on the body of the head on the base side, for example, the wiring of the drive motor will not be passed between the fixed side and the rotating part at the tip, and the cord will not get twisted or wrapped due to the rotation of the rotating body. There is no risk of the head moving or interfering with the work, etc., allowing the head to operate smoothly and giving a cleaner appearance.

Further, a rotation transmission cylinder is rotatably provided concentrically with the first hollow shaft, the second hollow shaft is rotated via the rotation transmission cylinder, and a harmonic drive reducer is provided in the second driving means, Simultaneously with the rotation of the first hollow shaft by the first driving means, this rotation is activated by the harmonic drive reducer on the second driving means side, so that the rotation transmission cylinder is also rotated at the same rotation as the first hollow shaft. Relative rotation between the first rotating bracket and the second hollow shaft due to the rotation of the first hollow shaft is prevented, and as a result, the second hollow shaft can also be rotationally driven independently by the second driving means, so that the two rotating shafts can be controlled. can be easily performed without using complicated correction means.

Moreover, the number of teeth in the transmission part can be set very easily, and the rotation is mechanically controlled, so the operation is reliable. especially,
- In a point-oriented processing head, each control signal for each rotation axis directly becomes a rotation angle signal, so
It does not require complicated calculation processing time in the control system, so it can be applied to high-speed drive, and the nozzle can always be controlled to an appropriate posture while maintaining the irradiation position according to the program, making it possible to perform highly accurate laser processing.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a head portion showing an embodiment of the laser processing head of the present invention, Fig. 2 is a partially enlarged sectional view of the same drive unit, and Fig. 3 is a sectional view of the main parts of the harmonic drive reducer. , FIG. 4 is an explanatory diagram showing an example of the output form as above. DESCRIPTION OF SYMBOLS 1... Head main body, 2... First hollow shaft, 3... First rotating bracket, 4... Second hollow shaft, 5... Second
Rotating bracket, 7... processing head, 16... first
1st drive motor as a drive means, 17... 2nd drive motor as a second drive means, 19... Harmonic drive reducer, 20... Rotation transmission cylinder, 29... As a first working wheel 30... Second operating gear as a second operating wheel, 32... Second circular spline, 34... Flex spline, 36... First operating gear.
Circular spline, 40... Web generator, 44... Transmission gear as a transmission wheel, 45... Interlocking gear as an interlocking wheel.

Claims (1)

[Claims] (1) A first rotary bracket integral with the first hollow shaft is rotatably supported on the head body via the first hollow shaft, and the second hollow shaft is connected to the first rotary bracket via the second hollow shaft. In the laser processing head which rotatably supports a second rotation bracket integral with the shaft and supports a lens holder at the tip of the second rotation bracket, the first
A first driving means for rotationally driving the hollow shaft and a second driving means for rotationally driving the second hollow shaft are respectively attached to the head body, and a rotation transmitting cylinder connected to the second hollow shaft so as to be rotationally transmittable is connected to the first The head body is rotatably supported concentrically with the hollow shaft, a first working wheel is integrally provided on the first hollow shaft, and a second working wheel is integrally provided on the rotation transmission cylinder, and the output of the second driving means is A web generator of a Harmonic Drive (registered trademark, hereinafter the same) reducer is connected to the shaft. a first circular spline which is internally connected to the spline;
It consists of a second circular spline which has a different number of teeth than the circular spline and is internally connected to the flex spline, and an interlocking wheel is integrally provided with the first circular spline and connected to the first operating wheel so as to be able to transmit rotation. , a transmission wheel is integrally provided on the second circular spline and connected to the second working wheel so as to be able to transmit rotation, and the web generator is fixed, the first circular spline is on the input side, and the second circular spline is on the output side. When the gear ratio of the harmonic drive reducer in this case is R, the number of teeth of the first working wheel Z_1, the number of teeth of the interlocking wheel Z_
2. Number of teeth of the transmission wheel Z_3 and number of teeth of the second working wheel Z_4
By setting the number of teeth so that the relationship satisfies the following formula (Z_1/Z_2) x R x (Z_3/Z_4) = 1, the rotation of the first hollow cylinder by the first driving means is controlled by the first working wheel, A laser processing head characterized in that the same rotation is transmitted to a rotation transmission cylinder via an interlocking wheel, a harmonic drive reducer, a transmission wheel, and a second working wheel.