JP2525285B2 - Torch rotating device for high-speed rotating arc welding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotating device for a welding torch used in a high-speed rotating arc welding device, and more particularly to a mechanism for automatically adjusting the rotating diameter of a welding arc.

[Prior Art] A high-speed rotary arc welding device performs arc welding while applying a high-speed circular motion (rotation) to an arc generated between an electrode wire and a member to be welded. As shown in, for example, Japanese Patent Laid-Open No. 62-104684, the device uses an eccentric gear to form an intermediate portion of the electrode so that the electrode through which the electrode wire passes through the center has a conical motion with the upper portion (the end portion on the electrode wire insertion side) as a fulcrum. The lower end of the electrode is rotated by eccentrically supporting the part by a predetermined amount.

A more specific description will be given. 6 (A) and 6 (B) are a schematic cross-sectional side view of the torch rotating device shown in the above publication and a cross-sectional plan view of an eccentric gear portion that causes rotation of the torch. As shown in the figure, the electrode wire 21 is fed through the center of the electrode 20, and an arc 30 is generated between the electrode wire 21 and the member 31 to be welded to perform welding. The upper part of the electrode 20 is supported by a self-aligning ball bearing 27, and the middle part is supported by an eccentric gear 25 via a self-aligning ball bearing 26.
Is engaged with a gear 24 attached to the shaft 23 of the motor 22 to rotate. As a result, the electrode 20 is supported by the upper self-aligning ball bearing 27 as a fulcrum, and the middle self-aligning ball bearing 27 is used as a fulcrum.
26 and the eccentric gear 25 eccentrically rotate to perform a conical motion. The eccentric gear 25 is rotatably supported by a bearing 34 in a gear box 28. Further, a power supply cable 29 is connected to the upper end portion of the electrode 20 by a tightening bolt 33 for supplying power to the electrode wire 21.

The eccentric amount of the eccentric gear 25 is set to a constant value d, and the self-aligning ball bearing 26 and the eccentric gear 25 cause the electrode 20 to perform a conical movement with the upper self-aligning ball bearing 27 as a fulcrum.
At the lower end of the electrode 20, the tip of the electrode wire 21 makes a circular motion with a diameter D. That is, the arc 30 rotates at a high speed with a diameter of D with respect to the welding line. For this reason, the penetration into the side wall of the groove increases, the bead surface is also smoothed, and a good bead shape is obtained, and the arc itself is detected by detecting the rotating position of the rotating arc 30, the arc voltage, and the welding current. The advantage of this arc sensor is that the groove center scanning control can be performed with high accuracy (Japanese Patent Publication No. 63-39346, Japanese Patent Laid-Open No. 57-91877).
issue).

By the way, since it is necessary to appropriately control the bead width and the penetration depth according to the size and shape of the groove, the type of welded joint, etc., the rotation diameter D of the tip of the electrode wire 21 depends on the type of the groove. Need to be adjusted. This adjustment of the rotating diameter is carried out by changing the distance 1 between the self-aligning ball bearing 27 and the eccentric gear 25. For this reason, the rotating diameter adjuster 32 is provided.

[Problems to be Solved by the Invention] However, in the adjusting method using the rotating diameter adjuster 32, the rotating diameter adjuster 32 becomes longer as the adjusting range of the rotating diameter D becomes larger, so that the welding torch also becomes longer and the weight increases and the size increases. . In particular, recently, the demand for equipping a robot with this welding torch has increased, and increasing the size and weight of the torch has increased the rigidity of the robot,
In addition to the large impact on strength and cost, there has been a demand for smaller size and lighter weight, and the manual adjustment method has a problem that automation and unmanned operation cannot be performed and versatility is reduced.

The present invention has been made in order to solve the above problems, and a torch rotating device for a high-speed rotating arc welding device, which can realize downsizing and weight saving of the torch and can automatically change the rotating diameter of the arc. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, a torch rotating device of a high-speed rotating arc welding device according to the present invention uses an upper end of an electrode (end part of an electrode wire insertion side) as a fulcrum, An eccentricity in which a middle part is supported by an eccentric rotating body which is driven to rotate to give a high-speed circular motion to a lower end of the electrode and a high-speed circular motion to a welding arc at a tip of an electrode wire passing through the center of the electrode. The rotating body is composed of a combination of an outer eccentric ring and an inner eccentric ring, which are separated into two parts, and a protrusion engaging elastically between the outer eccentric ring and the inner eccentric ring is provided so as to be able to move in and out. At a position of an arbitrary relative rotation angle, by a phase difference holding means for holding during rotation and a locking means for fixing the inner eccentric ring, the phase difference between the outer eccentric ring and the inner eccentric ring is stopped when the rotation is stopped. By automatically changing it, the rotating diameter of the welding arc can be automatically changed.

Further, the phase difference holding means is composed of a plurality of recesses provided on the outer peripheral surface of the inner eccentric ring, and a ball or a plunger that is pressed by a spring and engages with the recesses. Positioning is performed based on a position signal from the rotational position detector.

[Operation] When the electrode makes a circular (pyramidal) motion as described above, the eccentric amount of the eccentric rotating body is d, the distance from the fulcrum of the electrode to the electrode support portion of the eccentric rotating body is l, and the electrode is from the fulcrum of the electrode. When the distance to the tip of the wire is L, the rotation diameter at the tip of the electrode wire, that is, the rotation diameter D of the arc is given by the following equation.

From the equation (1), since the arc rotation diameter D changes depending on the eccentric amount d of the eccentric rotating body, the eccentric rotating body 10 is constituted by the outer eccentric ring and the inner eccentric ring, and the eccentric amount d is changed. This principle will be described with reference to FIGS. 4 and 5.

As shown in FIG. 4, the outer eccentric ring 1 with the eccentricity d _1, changing the angle of the combination of the inner eccentric ring 2 having an eccentric amount d _2, is the eccentricity d of eccentric rotation body is changed . Here, for simplicity, the eccentricity amounts d ₁ and d ₂ are equal to each other d ₁
Description will be made assuming that = d ₂ = d ₀ .

For example, FIG. 4A shows the case where the eccentric directions of the outer eccentric ring 1 and the inner eccentric ring 2 are both matched upward, and the phase difference (relative rotation angle) θ of both rings is 0 °. At this time, the amount of eccentricity d of the eccentric rotating body becomes maximum 2d ₀ . Further, the eccentric direction is upward, and the angle α in the eccentric direction based on the eccentric direction of the outer eccentric ring is 0 °.

(B) shows the case where the eccentric direction of the outer eccentric ring 1 is upward and the eccentric direction of the inner eccentric ring 2 is left, and the phase difference θ between both rings is 90 °. At this time, the eccentricity of the eccentric rotating body The eccentric direction and angle are diagonally upward to the left by 45 °.
Further, (C) shows the case where the eccentric direction of the outer eccentric ring 1 is upward and the eccentric direction of the inner eccentric ring 2 is downward, and the phase difference θ between both rings is 180 °. At this time, the eccentric amount d of the eccentric rotating body becomes 0 (minimum value), the eccentric direction and angle do not appear, and the eccentric rotating body becomes a perfect circle.

In this way, the eccentricity d of the eccentric rotating body changes within the range of 0 ≦ d ≦ 2d ₀ .

FIG. 5 is an explanatory diagram for obtaining the eccentric amount d of the eccentric rotating body and the eccentric direction angle α. In the figure, point A is the center of the outer diameter a of the outer eccentric ring, point B is the center of the inner diameter b of the outer eccentric ring, and the center of the outer diameter b of the inner eccentric ring, and point C is the inner diameter c of the inner eccentric ring. The center, that is, the center of the electrode, is displaced in the eccentric direction between the outer eccentric ring and the inner eccentric ring, that is, the phase difference is θ (0 ° ≦ θ ≦ 180 °), the eccentric amount of the outer eccentric ring is d ₁ , and the inner eccentric ring is If the eccentricity is d ₂ , the eccentricity d (AC length) of the eccentric rotating body is When d ₁ = d ₂ = d ₀ , Becomes

The eccentric direction angle α is When d ₁ = d ₂ = d ₀ , Becomes

Here, since d ₁ and d ₂ are constants (known values), if the phase difference θ is known, the eccentric amount d of the eccentric rotating body and the eccentric direction angle α can be obtained.

The eccentricity amount d and the eccentric direction angle α when the phase difference θ is changed are calculated from the equations (2) and (3), and the results are shown in Table 1.

The phase difference θ between the two rings is determined by positioning the outer eccentric ring and the inner eccentric ring at a required relative rotation angle by means of a phase difference holding means provided between the rings, for example, a spring pressure type ball plunger. To fix. Further, the inner eccentric ring is fixed by the locking means, and only the outer eccentric ring is rotated by the rotation motor 22 by a required angle to adjust the eccentric amount d of the eccentric rotating body. The rotation diameter D of the arc based on the eccentricity d is obtained from the equation (1). After that, if the locking means is released and the outer eccentric ring and the inner eccentric ring rotate together, the arc has a changed rotation diameter D. Rotates.

[Embodiment] FIG. 1 is a sectional side view showing an embodiment of the torch rotating device of the present invention, and FIGS. 2 and 3 are AA of FIG. 1, respectively.
It is a line sectional view and a BB line sectional view (however, Gabox is excluded).

In this embodiment, the eccentric rotating body 10 is composed of a combination of an outer eccentric ring 1 and an inner eccentric ring 2 which are separated into two parts.

The outer eccentric ring 1 has a gear 3 and is rotatably supported in a gear box 28 via upper and lower two bearings 34, and a drive gear attached to the shaft 23 of the motor 22 by the gear 3.
Engage 24 and rotate. The drive mechanism by the gears 3 and 24 is an example, and the outer eccentric ring 1 can be rotationally driven by a timing belt, a chain, or the like.

The inner eccentric ring 2 is closely inserted inside the outer eccentric ring 1. That is, as also shown in FIG. 4, the outer diameter b of the inner eccentric ring 2 and the inner diameter b of the outer eccentric ring 1 are formed substantially equal to each other with a minute gap allowing relative rotation. Also it may be equally eccentric amount d ₁ and eccentricity d ₂ of the inner eccentric ring 2 of the outer eccentric ring 1 may be a different value. In any case, the eccentric amount d of the eccentric rotating body 10
And the eccentric direction angle α can be calculated by the equation (2) and (3) if the phase difference θ is known. Therefore, a required number of phase difference holding means 15 for holding the relative rotation angle (phase difference) during rotation are provided between the outer eccentric ring 1 and the inner eccentric ring 2. As described above, the phase difference holding means 15 holds the eccentric amount d and the eccentric direction of the eccentric rotating body 10 during rotation. In FIG. 2, the eccentric direction of the eccentric rotating body 10 is rightward.

The phase difference holding means 15 is composed of a spring-pressurized ball plunger as shown in FIGS. 1 and 3, and has a recess 17 on the outer peripheral surface of the inner eccentric ring 2 for engaging the ball 16 at an equal angle. A required number of balls 16 are provided, and the ball 16 is constantly pressed toward the recess 17 by a spring 19 interposed between the ball 16 and the set screw 18.

The electrode 20 penetrates through the eccentric rotating body 10 and has an upper portion supported by a gear box 28 via a self-aligning ball bearing 27 and an intermediate portion supported by the inner eccentric ring 2 via a self-aligning ball bearing 26. Has been done. In the figure, 5 is an insulator for mounting the self-aligning ball bearing 26, which electrically insulates the rotating mechanism portion including the self-aligning ball bearing 26 from the electrode 20 and which is also an electrode.
It is held at a predetermined position of 20. Similarly, the electrode
A similar insulator 6 is also provided for the self-aligning ball bearing 27 that constitutes the fulcrum of 20.

Furthermore, a locking means 35 is provided for fixing the inner eccentric ring 2 as required. The locking means 35 is composed of an air cylinder 36, and the rotation of the inner eccentric ring 2 is blocked by inserting the tip of a rod 37 thereof into a positioning hole 38 provided in the inner eccentric ring 2. The position of the positioning hole 38 of the inner eccentric ring 2 is detected based on the rotation position signal from the encoder 39 which detects the rotation position of the motor 22. The locking means 35 may be composed of a solenoid operated plunger. A nozzle gas nozzle cover and the like (not shown) are attached below the gear box 28.

With the above configuration, the electrode 20 causes the outer eccentric ring 1 and the inner eccentric ring 2 to make a circular motion at the support point of the intermediate self-aligning ball bearing 26, so that the upper self-aligning ball bearing 27 As a fulcrum, the lower end of the electrode makes a circular motion.

This causes the tip of the electrode wire 21 passing through the center of the electrode 20 to rotate with a diameter D. That is, the rotational diameter D of the arc 30 is obtained from the equation (1) as described above.

 Next, a method of changing the rotation diameter D will be described.

First, based on the rotational position signal from the encoder 39 of the motor 22, the inner eccentric ring 2 is positioned so that the positioning hole 38 of the inner eccentric ring 2 coincides with the position of the rod 37 of the air cylinder 36.
Align the position of. After this alignment is completed, the rod 37 is projected by the air cylinder 36 and inserted into the positioning hole 38 of the inner eccentric ring 2 to lock the inner eccentric ring 2.

Next, the motor 22 is rotated by a predetermined angle while the inner eccentric ring 2 is locked. At this time, the outer eccentric ring 1
With the rotation of, the ball 16 of the phase difference holding means 15 escapes from the concave portion 17 with which the ball 16 is engaged against the force of the spring 19,
Since the operation of entering the next concave portion 17 in the rotation direction and further coming out of this concave portion 17 is repeated, finally, the ball 16 engages with the concave portion 17 facing the ball 17 at the position of the predetermined rotation angle of the outer eccentric ring 1. Lock the inner eccentric ring 2. As a result, both rings are integrated, the required phase difference θ is maintained, and the rotation diameter D can be changed. Further, the phase difference θ can be set depending on the number of the concave portions 17 so as to be coarse or fine.
Further, the rotation diameter adjusting controller (not shown) is used for the rotation position of the outer eccentric ring 1 and the inner eccentric ring 2, that is, the rotation diameter D.
Always remembers.

After changing the rotation diameter D in this way, the rod 37 of the air cylinder 36 is pulled out from the positioning hole 38 to free the inner eccentric ring 2.

As described above, the rotating diameter D of the arc 30 can be changed automatically and in a wide range. Also, since the total length of this welding torch can be shortened compared to the conventional one, the locking means 3
Even if the inner eccentric ring 2, the phase difference holding means 15 and the like are added, the entire torch can be made substantially compact and lightweight.

[Effects of the Invention] As described above, according to the present invention, an eccentric rotating body is constituted by a combination of two outer and inner eccentric rings, and a phase difference holding means and a locking means are used to reduce the phase difference between both eccentric rings. Since the eccentric amount of the eccentric rotating body is automatically changed by changing it arbitrarily, the rotating diameter of the arc can be automatically changed, and the arc welding can be automated and unmanned. Further, since the total length of the torch can be made shorter than that of the conventional one, the entire torch can be made substantially smaller and lighter, and it can be applied to a welding robot and can be more versatile, which is a great effect.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an embodiment of the torch rotating device of the present invention, and FIGS. 2 and 3 are sectional views taken along the lines AA and BB of FIG. (Excluding the box), FIG. 4 is a principle diagram showing a method of changing the eccentric amount and the eccentric direction of the eccentric rotary member in the present invention, and FIG. 5 is an explanatory diagram for obtaining the eccentric amount and the eccentric direction angle of the eccentric rotary member. ,
6 (A) and 6 (B) are a schematic sectional side view of a conventional torch rotating device and a cross-sectional plan view of an eccentric rotating portion thereof. 1 …… Outer eccentric ring 2 …… Inner eccentric ring 3 …… Gear 5 …… Insulator 6 …… Insulator 10 …… Eccentric rotor 15 …… Phase difference holding means 16 …… Ball 17 …… Concave 18 …… Set screw 19 …… Spring 20 …… Electrode 21 …… Electrode wire 22 …… Motor 23 …… Axis 24 …… Gear 26 …… Self-aligning ball bearing 27 …… Self-aligning ball bearing 28 …… Gear box 30… … Welding arc 31 …… Welding member 34 …… Bearing 35 …… Locking means 36 …… Air cylinder 37 …… Rod 38 …… Positioning hole 39 …… Encoder

Claims (3)

(57) [Claims] 1. An upper end of an electrode (an end on the electrode wire insertion side) is used as a fulcrum, and an intermediate part of the electrode is supported by an eccentric rotating body which is rotationally driven to impart a high-speed circular motion to the lower end of the electrode. In a high-speed rotating arc welding device for welding while rotating the welding arc at the tip of the electrode wire passing through the center of the electrode at a high speed, the eccentric rotor comprises a combination of an outer eccentric ring and an inner eccentric ring separated into two, and A protrusion that is elastically engaged is provided between the outer eccentric ring and the inner eccentric ring so as to be able to move in and out, and a phase difference holding unit that holds both rings at a position of an arbitrary relative rotation angle during rotation; Locking means for fixing the eccentric ring automatically changes the rotating diameter of the welding arc by automatically changing the phase difference between the outer eccentric ring and the inner eccentric ring when the rotation is stopped. A torch rotating device for a high-speed rotating arc welding device characterized by making it possible. 2. The phase difference holding means comprises a plurality of recesses provided on the outer peripheral surface of the inner eccentric ring, and balls or plungers that are pressed by a spring and engage with the recesses. The torch rotating device of the high-speed rotating arc welding device according to claim 1. 3. The torch rotating device for a high-speed rotary arc welding device according to claim 1, wherein the lock position of the lock means is determined based on a position signal from a rotary position detector of the electrode.