JP7291949B2 - tip dresser - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tip dresser for cutting an electrode tip for resistance welding, so-called a swivel tip, in which a main body located on the tip side is configured to be swivelable.

Conventionally, a resistance welding method using an electrode tip called a so-called swivel tip has been known. It is configured to be rotatable around the central axis. The base of the swivel tip is attached to the tip of a welding gun for resistance welding. Since the main body of the swivel tip is tilted with respect to the base according to the inclination of the contact surface of the body, it is possible to prevent dents from being left on the surface of the object to be welded, and the main body of the swivel tip remains intact even after repeated resistance welding. The welding quality can be stabilized by reducing variations in the contact area of the tip with respect to the object to be welded.

Japanese Patent Application No. 2019-58948

By the way, if resistance welding is repeated, an oxide film will adhere to the tip of the electrode tip. It is necessary to remove the oxide film. In this tip dresser, the tip of an electrode tip attached to a welding gun is cut by the cutting edge of the rotating cutter by bringing the tip of the electrode tip into contact with the rotating cutter with the central axis of the electrode tip aligned with the axis of rotation. is common.

However, in the case of the swivel tip as disclosed in Patent Document 1, since the main body can be turned about the central axis of the swivel tip with respect to the base, if cutting work is performed with a general tip dresser as described above, the swivel will When the main body of the tip is brought into contact with the rotary cutter, the main body moves relative to the base, and the tip of the main body cannot be cut cleanly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a tip dresser capable of cleanly cutting an electrode tip for resistance welding, the main body of which is rotatable with respect to the base. to provide.

In order to achieve the above object, the present invention is characterized by devising a state in which the main body of the electrode tip cannot be rotated so that the front end of the main body of the electrode tip can be brought into contact with the rotating cutter. .

Specifically, the object is a tip dresser for cutting an electrode tip for resistance welding in which the main body located on the tip side is configured to be rotatable about the central axis with respect to the base, and the following solutions are taken. .

That is, in the first invention, a rotary cutter having a cutting edge, a dresser main body that supports the rotary cutter rotatably around a rotation axis, and a dresser body that is slidable along the rotation axis, and an electrode fixing unit capable of fixing the main body of the electrode tip so that the central axis coincides with the rotation axis, the electrode fixing unit fixing the main body of the electrode tip in a rotating state; By sliding toward the rotary cutter, the front end of the main body of the electrode tip is brought into contact with the cutting edge for cutting.

In a second aspect of the invention, in the first aspect, a side surface of the body portion of the electrode tip is provided with a tapered surface portion whose diameter gradually decreases toward the tip of the body portion; and a fixing hole having a tapered inner peripheral surface corresponding to the tapered surface portion is formed through the rotation axis, and the rotation relative to the fixing plate a load generating mechanism for generating a load in a direction away from the cutter, the body portion of the electrode tip being inserted into the fixed hole from the opposite side of the rotary cutter, and the tapered surface portion being placed on the inner peripheral surface of the fixed hole. In addition, the fixing plate slides together with the electrode tip toward the rotary cutter in a rotating state by pushing the main body into the fixing hole by a pushing force exceeding the load generated by the load generating mechanism. The tip of the main body of the electrode tip is brought into contact with the cutting edge for cutting.

In a third invention according to the second invention, the load generating mechanism is a plurality of spring members provided at positions equidistant from the rotation axis, and the fixing is performed by extending or contracting the spring members. It is characterized by generating a load on the plate.

In a fourth aspect of the invention, in the second aspect, the load generating mechanism is a fluid pressure cylinder in which a tip end of a piston rod is connected to the fixed plate, and the extension or contraction of the piston rod causes the load to be applied to the fixed plate. It is characterized by generating a load.

In the first invention, the central axis of the electrode tip is aligned with the rotation axis of the rotating cutter by the electrode fixing unit, and the main body of the electrode tip cannot be rotated with respect to the base, so that the electrode fixing unit is rotated. When it is moved toward the cutter, the main body comes into contact with the rotary cutter in a state where the central axis of the electrode tip is aligned with the rotation axis and the main body cannot rotate. Therefore, the tip of the main body can be cut by the cutting edge of the rotary cutter without the main body moving with respect to the base, and the tip of the main body can be cut cleanly.

In the second invention, when the main body of the electrode tip is inserted into the fixing hole, the tapered surface of the main body of the electrode tip slides against the inner peripheral surface of the fixing hole, and the electrode tip moves along the central axis of the electrode tip. The main body of the electrode tip is fixed in the fixing hole in a state where the rotation axis of the rotary cutter is aligned. When the electrode tip is further pushed into the fixing hole, the body of the electrode tip is firmly fixed to the fixing hole by the load generated by the load generating mechanism acting on the opposite side of the pushing direction of the electrode tip. Due to the pushing force exceeding the load, the electrode tip moves toward the rotary cutter in the rotating state together with the fixed plate while the center axis of the electrode tip is aligned with the rotation axis. In this way, only by inserting and pushing the electrode tip into the fixing hole, the operation of aligning the center axis of the electrode tip with the rotation axis and the operation of fixing the main body of the electrode tip can be performed. , the device can be simple in structure and low in cost.

In the third invention, when the main body of the electrode tip is inserted into the fixing hole, a load (biasing force) is evenly applied from each spring member to the main body of the electrode tip. is fixed to the fixing hole, the main body of the electrode tip can be firmly fixed to the fixing hole while the central axis of the electrode tip is not inclined with respect to the rotation axis of the rotating cutter.

In the fourth invention, since the fluid pressure cylinder generates the load applied to the fixed plate in the direction away from the rotary cutter, the load value is constant regardless of the position of the fixed plate with respect to the rotary cutter. Therefore, it is possible to prevent variation in the cutting state of the tip of the electrode tip even if the cutting operation of the electrode tip is repeatedly performed.

1 is a perspective view of a tip dresser according to Embodiment 1 of the present invention; FIG. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, showing a state immediately before cutting an electrode tip. FIG. 3 is a diagram showing a state immediately after starting the cutting operation of the electrode tip after FIG. 2 ; It is a figure which shows the state in the middle of performing the cutting operation of an electrode tip after FIG. FIG. 1 is a view corresponding to FIG. 1 according to Embodiment 2 of the present invention. FIG. 2 is a view equivalent to FIG. 2 according to Embodiment 2 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. It should be noted that the following description of preferred embodiments is merely exemplary in nature.

<<Embodiment 1 of the invention>>
FIG. 1 shows a tip dresser 1 according to Embodiment 1 of the present invention. This tip dresser 1 is for cutting the tip of a swivel tip 10 (electrode tip) attached to a shank G1 of a welding gun G for a resistance welder, and has a substantially H shape in plan view and a thickness. a plate-shaped dresser main body 2 having a drive motor 3 fixed to the lower part of the dresser main body 2 and having a rotating shaft (not shown) extending upward and positioned inside the dresser main body 2; The dresser body 2 and the drive motor 3 are provided with a shock absorption mechanism 4 that absorbs vertical shocks applied to the dresser main body 2 and the drive motor 3 .

As shown in FIGS. 2 to 4, the swivel tip 10 includes a body portion 10a having a short, substantially cylindrical shape whose circular tip is brought into contact with an object to be welded (not shown) during welding, and a body portion 10a. A rod-shaped base portion 10b having a circular cross section is provided on the base end side, and the base portion 10b is attached to the shank G1 of the welding gun G. As shown in FIG.

A tapered surface portion 10c is provided on the side surface of the main body portion 10a, the diameter of which gradually decreases as it approaches the tip of the main body portion 10a. 10d is formed.

A hemispherical portion 10e is provided on the main body portion 10a side of the base portion 10b so as to be slidably fitted in the fitting recess 10d. (see arrow X1 in FIG. 2).

As shown in FIG. 2, a hollow portion 2a is provided inside the dresser body 2, and a communication hole 2b communicating with the hollow portion 2a is formed in the front upper surface of the dresser body 2. As shown in FIG.

At a position corresponding to the communication hole 2b in the hollow portion 2a of the dresser body 2, a ring-shaped output gear 5 is rotatably mounted around a vertically extending rotation axis C1 via a pair of upper and lower bearings Be1. there is

The output gear 5 rotates around the rotation axis C1 through a gear meshing mechanism (not shown) provided between the drive motor 3 and the output gear 5 in the hollow portion 2a by rotational driving of the drive motor 3. It's like

A mounting hole 5a penetrating vertically is provided in the center of the output gear 5, and a rotary cutter 6 for cutting the tip of the swivel tip 10 is mounted in the mounting hole 5a.

That is, the dresser main body 2 supports the rotary cutter 6 via the output gear 5 so as to be rotatable around the rotation axis C1.

The rotary cutter 6 has a substantially T-shape when viewed from the side, and an electrode receiving portion 6a having a shallow and wide concave shape is formed on the upper surface of the rotary cutter 6 . The shape of the electrode receiving portion 6a corresponds to the tip portion of the body portion 10a of the swivel tip 10. As shown in FIG.

The electrode receiving portion 6a is provided with a cutting edge portion 6b extending in a direction intersecting with the rotation axis C1. When brought into contact with the stop portion 6a, the cutting edge portion 6b cuts the tip of the body portion 10a.

At a position corresponding to the rotating cutter 6 on the lower surface of the dresser body 2, a curved surface portion 2e that opens downward is formed. None.

A block-shaped slide support portion 2c is provided on each side surface of the dresser main body 2 on the front side. Each slide support portion 2c is formed with a slide hole 2d penetrating vertically, and a slide rod 7 is slidably fitted in each slide hole 2d.

Above the communication hole 2b in the dresser main body 2, a fixing plate 8 having a substantially strip shape is provided horizontally extending in the direction in which the two slide support portions 2c are arranged side by side.

Each end of the fixed plate 8 is fixed to the upper end of each slide rod 7, and the fixed plate 8 is slidable along the rotation axis C1.

A fixing hole 8a penetrating vertically is formed in the center of the fixing plate 8, and the center of the fixing hole 8a coincides with the rotation axis C1.

The inner peripheral surface of the fixed hole 8a has a tapered shape corresponding to the tapered surface portion 10c of the swivel tip 10. When the body portion 10a of the swivel tip 10 is inserted into the fixed hole 8a from the opposite side of the rotary cutter 6, the swivel tip The body portion 10a of the swivel tip 10 is fixed to the fixing hole 8a so that the central axis C2 of the swivel tip 10 coincides with the rotation axis C1.

Between the dresser main body 2 and the fixed plate 8, a spring member 9 (a load generating mechanism) is provided at a position close to each slide support portion 2c. ) are provided two by two in the front-rear direction of the dresser main body 2 at predetermined intervals.

That is, the four spring members 9 are provided at equidistant positions from the rotation axis C1. In addition, the spring member 9 of Embodiment 1 of the present invention is a coil spring.

The two slide rods 7, the fixing plate 8 and the spring member 9 constitute the electrode fixing unit 11 of the present invention. As shown in FIGS. The main body portion 10a is fixed to the fixed plate 8 by inserting it from the opposite side of the rotary cutter 6 and making the tapered surface portion 10c correspond to the inner peripheral surface of the fixing hole 8a. The main body portion 10a is pushed into the fixed hole 8a by a pushing force exceeding the load generated by the two spring members 9, so that the fixed plate 8 slides together with the swivel tip 10 toward the rotary cutter in a rotating state. Cutting is performed by bringing the tip of the portion 10a into contact with the cutting edge portion 6b.

Next, the cutting operation of the swivel tip 10 using the tip dresser 1 will be described in detail. The swivel tip 10 is attached to one shank G1 of the C-shaped welding gun G, and the other shank G1 is attached with an electrode tip 12 for general spot welding.

First, as shown in FIG. 2, the swivel tip 10 and the electrode tip 12 attached to the welding gun G are moved upward and downward of the dresser main body 2, respectively, and the central axis C2 of the swivel tip 10 is rotated. Match C1. At this time, the tip portion of the electrode tip 12 is fitted to the curved surface portion 2e.

Next, the drive motor 3 of the tip dresser 1 is rotated to rotate the rotary cutter 6 around the rotation axis C1.

Next, as shown in FIG. 3, the shank G1 to which the swivel tip 10 is attached is lowered. Then, the body portion 10a of the swivel tip 10 is inserted into the fixed hole 8a from the opposite side of the rotary cutter 6, and the tapered surface portion 10c moves while sliding against the inner peripheral surface of the fixed hole 8a, so that the central axis C2 becomes the rotation axis C1. , the body portion 10a is fixed to the fixing hole 8a.

Thereafter, the shank G1 to which the swivel tip 10 is attached is further lowered to apply a pushing force exceeding the load (biasing force) generated by the contraction of the four spring members 9 to the main body portion 10a. Then, as shown in FIG. 4, the body portion 10a of the swivel tip 10 is further pushed into the fixing hole 8a, and the body portion of the swivel tip 10 is pushed by the loads of the four spring members 9 acting in the direction opposite to the pushing direction of the swivel tip 10. The 10a moves toward the rotating cutter 6 together with the fixed plate 8 while being firmly fixed to the fixed hole 8a and with the center axis C2 aligned with the rotation axis C1. Then, the fixed plate 8 slides along the rotation axis C1, and the tip of the body portion 10a of the swivel tip 10 enters the electrode receiving portion 6a of the rotary cutter 6 in a rotating state and contacts the cutting edge portion 6b. be cut.

As described above, according to the first embodiment of the present invention, the central axis C2 of the swivel tip 10 is aligned with the rotation axis C1 of the rotary cutter 6 by the electrode fixing unit 11, and the body portion 10a of the swivel tip 10 is positioned at the base portion. 10b, when the electrode fixing unit 11 is moved toward the rotary cutter 6, the main body 10a becomes non-rotatable while the central axis C2 of the swivel tip 10 coincides with the rotation axis C1. The rotary cutter 6 comes into contact with the state. Therefore, the body portion 10a of the swivel tip 10 does not move with respect to the base portion 10b, and the tip of the body portion 10a is cut by the cutting edge portion 6b of the rotary cutter 6, and the tip of the body portion 10a is cut cleanly. be able to.

In addition, only by inserting and pushing the swivel tip 10 into the fixing hole 8a, both the operation of aligning the central axis C2 of the swivel tip 10 with the rotation axis C1 and the operation of fixing the body portion 10a of the swivel tip 10 can be performed. Therefore, the tip dresser 1 having a simple structure and low cost can be obtained.

Further, since the four spring members 9 are arranged at equal intervals from the rotation axis C1, when the main body portion 10a of the swivel tip 10 is inserted into the fixing hole 8a, the main body portion of the swivel tip 10 is displaced from the four spring members 9. A load (biasing force) is evenly applied to the swivel tip 10a. The body portion 10a of the swivel tip 10 can be firmly fixed to the fixing hole 8a while preventing it from tilting.

In Embodiment 1 of the present invention, four spring members 9 are arranged to apply a load to the fixed plate 8, but the structure may be such that one to three spring members 9 apply a load to the fixed plate 8. However, the structure may be such that five or more spring members 9 apply a load to the fixing plate 8 .

Also, in Embodiment 1 of the present invention, a coil spring is used as the spring member 9, but other types of springs may be used.

Further, in Embodiment 1 of the present invention, each spring member 9 is structured to apply a load to the fixing plate 8 by contracting, but each spring member 9 is structured to apply a load to the fixing plate 8 by expanding. may

<<Invention Embodiment 2>>
5 and 6 show a tip dresser 1 according to Embodiment 2 of the present invention. The second embodiment is the same as the first embodiment except for a mechanism for applying a load to the fixing plate 8 and a partial structure of the fixing plate. only explain.

The fixing plate 8 in the second embodiment is provided with a rectangular plate-like mounting portion 8c extending toward the back side of the dresser body 2, and a through hole 8b is formed through the central portion of the mounting portion 8c. .

A fluid pressure cylinder 13 (load generating mechanism) is fixed to the upper surface of the mounting portion 8c, and a piston rod 13a of the fluid pressure cylinder 13 is inserted in the through hole 8b so as to be extendable. In addition, the fluid pressure cylinder 13 of Embodiment 2 of the present invention is an air cylinder.

The tip of the piston rod 13a is fixed to the upper surface of the dresser body 2, and the extension of the piston rod 13a can generate a load on the fixed plate 8 in the direction away from the rotary cutter 6.

The two slide rods 7, the fixing plate 8 and the fluid pressure cylinder 13 constitute an electrode fixing unit 11 according to the second embodiment of the present invention. The main body portion 10a is fixed to the fixing plate 8 by inserting it from the opposite side and making the tapered surface portion 10c correspond to the inner peripheral surface of the fixing hole 8a. The main body portion 10a is pushed into the fixed hole 8a by a pushing force exceeding the load generated by the extension operation, and the fixed plate 8 slides together with the swivel tip 10 toward the rotary cutter in a rotating state. Cutting is performed by bringing the tip into contact with the cutting edge portion 6b.

The operation of cutting the swivel tip 10 using the tip dresser 1 of Embodiment 2 of the present invention is the same except for the load generating mechanism that applies a load to the fixed plate 8, so detailed description will be omitted. .

As described above, according to the second embodiment of the present invention, since the fluid pressure cylinder 13 generates a load applied to the fixed plate 8 in the direction away from the rotary cutter 6, regardless of the position of the fixed plate 8 with respect to the rotary cutter 6, The load value becomes constant. Therefore, even if the operation of cutting the swivel tip 10 is repeated, the cutting state of the tip of the swivel tip 10 can be kept from varying.

In Embodiments 1 and 2 of the present invention, the main body portion 10a of the swivel tip 10 is fixed to the fixing plate 8 using the fixing hole 8a. The body portion 10a may be fixed to the fixing plate 8 using a clamping unit or the like that clamps.

Further, in Embodiment 2 of the present invention, the fluid pressure cylinder 13 is configured to apply a load to the fixed plate 8 by extending the fluid pressure cylinder 13. may

Further, in Embodiment 2 of the present invention, an air cylinder is used as the fluid pressure cylinder 13, but for example, a hydraulic cylinder may be used.

INDUSTRIAL APPLICABILITY The present invention is suitable for a tip dresser for cutting an electrode tip for resistance welding, so-called a swivel tip, in which a main body located on the distal end side is configured to be rotatable.

REFERENCE SIGNS LIST 1 tip dresser 2 dresser body 6 rotary cutter 6b cutting edge 8 fixing plate 8a fixing hole 9 spring member (load generating mechanism)
10 swivel tip (electrode tip)
Reference Signs List 10a body portion 10b base portion 10c tapered surface portion 11 electrode fixing unit 13 fluid pressure cylinder (load generating mechanism)
C1 Rotation axis C2 Central axis

Claims (4)

A tip dresser for cutting an electrode tip for resistance welding in which a main body located on the tip side is configured to be able to turn around a central axis with respect to a base,
a rotating cutter having a cutting edge;
a dresser body rotatably supporting the rotary cutter around a rotation axis;
an electrode fixing unit configured to be slidable along the rotation axis and capable of fixing the main body of the electrode tip so that the central axis coincides with the rotation axis;
The electrode fixing unit slides toward the rotary cutter in a rotating state while fixing the main body of the electrode tip, thereby bringing the front end of the main body of the electrode tip into contact with the cutting edge for cutting. A tip dresser characterized by being configured as follows. The tip dresser according to claim 1,
A side surface of the main body of the electrode tip is provided with a tapered surface portion that gradually decreases in diameter as it approaches the tip of the main body,
The electrode fixing unit is configured to be slidable along the rotation axis, and a fixing plate having a fixing hole having a tapered inner peripheral surface corresponding to the tapered surface portion formed through the rotation axis. and a load generating mechanism that generates a load on the fixed plate in a direction away from the rotating cutter,
The body portion of the electrode tip is inserted into the fixed hole from the opposite side of the rotary cutter, the tapered surface portion is made to correspond to the inner peripheral surface of the fixed hole, and the pushing force exceeds the load generated by the load generating mechanism. by pushing the main body into the fixing hole, the fixing plate slides together with the electrode tip toward the rotary cutter in a rotating state, and the front end of the main body of the electrode tip is brought into contact with the cutting edge. A tip dresser configured to cut. The tip dresser according to claim 2,
The load generating mechanism is a plurality of spring members provided at positions equidistant from the axis of rotation, and generates a load on the fixed plate by extending or contracting the spring members. dresser. The tip dresser according to claim 2,
The tip dresser is characterized in that the load generating mechanism is a fluid pressure cylinder in which a tip end of a piston rod is connected to the fixed plate, and generates a load on the fixed plate by extending or contracting the piston rod.

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