TIP DRESSING CUTTER

Abstract

A tip dressing cutter (1) includes a rotary holder (5) and a cutter plate (2). The cutter plate (2) includes a cutting blade portion (2d) formed on a continuous portion of a rake face (2a) and a flank face (2b) and extending along a direction intersecting with a rotation axis (C1). A plurality of recessed grooves (2e) are formed on the flank face (2b), the plurality of recessed grooves (2e) extending from a location proximate to the cutting blade portion (2d) in a circumferential direction around the rotation axis C1 away from the cutting blade portion (2d) and being spaced at predetermined intervals along a direction intersecting with the rotation axis (C1).

Claims

1. A tip dressing cutter comprising a rotary holder configured to be rotatable about its rotation axis and a cutter plate attached to the rotary holder, the cutter plate configured to contact a distal end of a spot welding electrode tip brought into proximity to the rotating rotary holder with a central axis of the electrode tip being aligned with the rotation axis and to cut the distal end, the cutter plate comprising a rake face extending to intersect with a circumferential extent around the rotation axis; a flank face configured to face the distal end of the electrode tip when the electrode tip is brought into proximity to the rotary holder; and a cutting blade portion formed on a continuous portion of the rake face and the flank face and extending along a direction intersecting with the rotation axis, the cutting blade portion configured to cut the distal end of the electrode tip brought into proximity to the rotary holder, wherein a plurality of recessed grooves are formed on the flank face, the plurality of recessed grooves extending from a location proximate to the cutting blade portion in a circumferential direction around the rotation axis away from the cutting blade portion and being spaced at predetermined intervals along a direction intersecting with the rotation axis.

2. The tip dressing cutter according to claim 1, wherein the recessed grooves are each sloped to have a depth presenting a gentle increase as the recessed grooves extend away from the cutting blade portion.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a perspective view of a tip dresser according to an embodiment of the present disclosure.

[0013] FIG. 2 is a cross-sectional view taken along a plane II-II indicated in FIG. 1.

[0014] FIG. 3 is a perspective view of a rotary holder to which a cutter according to an embodiment of the present disclosure is attached.

[0015] FIG. 4 is a perspective view of a cutter according to an embodiment of the present disclosure.

[0016] FIG. 5 is an enlarged view of a part V indicated in FIG. 2.

DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure are described in detail below with reference to the drawings. It is noted that following description of the preferred embodiments is merely an example in nature.

[0018] FIG. 1 illustrates a tip dresser 10 according to an embodiment of the present disclosure. The tip dresser 10 is used for cutting distal ends 11a of a pair of electrode tips 11 (see FIG. 2) fitted onto respective shanks of a welding gun (not shown) to be opposite one another. The tip dresser 10 includes a cylindrical motor housing 10a having a cylinder center line oriented vertically, a plate-shaped housing 10b extending horizontally from an upper end of the motor housing 10a, and a shock absorbing mechanism 10c attached to a side of the motor housing 10a and configured to absorb impact applied vertically on the motor housing 10a and the plate-shaped housing 10b. A drive motor (not shown) having a rotation axis extending upward is housed inside the motor housing 10a.

[0019] As illustrated in FIG. 2, a pair of circular through holes 10d facing each other are formed in respective top and bottom surfaces of the plate-shaped housing 10b on an extension end side of the plate-shaped housing 10b.

[0020] In an interior of the plate-shaped housing 10b and between the through holes 10d, a ring-shaped output gear 6 is mounted rotatably about a vertically extending rotation axis C1 via a pair of upper and lower bearings 7. The output gear 6 is configured to be rotated about the rotation axis C1 by the drive motor and a gear meshing mechanism that are not shown.

[0021] The output gear 6 has at a center thereof a mounting hole 6a extending therethrough vertically. A cutter 1 is then mounted in the mounting hole 6a.

[0022] The cutter 1 has a rotary holder 5 generally C-shaped in planar view and configured to be rotatable about the rotation axis C1 extending vertically. The rotary holder 5, as illustrated in FIG. 3, includes a cutaway part 5a having a gentle circumferential expansion around the rotation axis C1 as the rotary holder 5 extends radially outwardly from the rotation axis C1, and the cutaway part 5a then being open outwardly.

[0023] A flange 5b extending outwardly beyond other portions of the rotary holder 5 is formed on an upper peripheral edge of the rotary holder 5.

[0024] Then, as illustrated in FIGS. 2 and 3, a pair of fitting surfaces 5c are formed on respective top and bottom surfaces of the rotary holder 5 to be arranged symmetrically along a direction of the rotation axis C1, and the fitting surfaces 5c are formed to have a gradual decrease in diameter toward a center portion of the rotary holder 5.

[0025] The fitting surfaces 5c have a shape corresponding to a curved shape of a distal end 11a of an electrode tip 11 and fitted with a distal end 11a of an electrode tip 11 with a central axis of the electrode tip 11 being aligned with the rotation axis C1.

[0026] An attachment step portion 5d is formed on one of inner faces of the cutaway part 5a extending outwardly from the rotation axis C1. The attachment step portion 5d is generally T-shaped in side view and recessed to form a step.

[0027] A metal cutter plate 2 for cutting a distal end 11a of an electrode tip 11 is attached to the attachment step portion 5d.

[0028] As illustrated in FIGS. 3 and 4, the cutter plate 2 is formed by cutting a metal plate into a general T-shape. The cutter plate 2 is secured to the attachment step portion 5d by means of a screw 3 and a washer 4 through an attachment hole 2f formed at a substantial center portion thereof.

[0029] The cutter plate 2 has one plate face facing a bottom surface of the attachment step portion 5d in the state where the cutter plate 2 is attached to the attachment step portion 5d, and the other plate face forming a rake face 2a. The rake face 2a extends to intersect with a circumference extent around the rotation axis C1.

[0030] A pair of flank faces 2b are formed on respective upper and lower parts of the rake face 2a. The flank faces 2b are generally orthogonal to the rake face 2a.

[0031] Thus, the pair of flank faces 2b are formed to be spaced at a predetermined interval along the direction of the rotation axis C1. Both of the flank faces 2b have a curved shape such that the flank faces 2b are progressively spaced apart from each other along the direction of rotation axis C1 as the flank faces 2b extend away from the rotation axis C1.

[0032] Both of the flank faces 2b then have a shape corresponding to the respective fitting surfaces 5c in the state where the cutter plate 2 is attached to the rotary holder 5. When electrode tips 11 are brought into proximity to the flank faces 2b with the central axes of the electrode tips 11 being aligned with the rotation axis C1, the flank faces 2b face respective distal ends 11a of the electrode tips 11.

[0033] A pair of positioning recesses 2c cut away rectangularly in side view are formed in respective top and bottom portions of the cutter plate 2 on a side of the cutter plate 2 away from the rotation axis C1.

[0034] A pair of cutting blade portions 2d extending to have a gentle curve in a direction intersecting with the rotation axis C1 are formed on respective continuous portions of the rake face 2a and the flank faces 2b to be arranged symmetrically along the direction of the rotation axis C1.

[0035] A plurality of recessed grooves 2e are formed on the flank faces 2b. The plurality of recessed grooves 2e each extend from a location proximate to the cutting blade portion 2d in a circumferential direction around the rotation axis C1 away from the cutting blade portion 2d and are spaced at equal intervals along the direction intersecting with the rotation axis C1.

[0036] The recessed grooves 2e are each generally V-shaped in cross-sectional view and sloped to have an increasing depth as the recessed grooves 2e extend away from the cutting blade portion 2d.

[0037] When electrode tips 11 are then brought into contact with the cutter 1 rotated in a X1 direction with the central axes of the electrode tips 11 being aligned with the rotation axis C1, the cutting blade portions 2d of the cutter plate 2 contact respective distal ends 11a of the electrode tips 11 to cut the distal ends 11a and then peripheral edges of opening portions of the recessed grooves 2e come into contact with the distal ends 11a, as illustrated in FIG. 5.

[0038] Next, a cutting operation for distal ends 11a of electrode tips 11 by using the tip dresser 10 is described.

[0039] First, as illustrated in FIG. 2, a pair of electrode tips 11 having distal ends 11a in a deteriorated condition are moved above and below the plate-shaped housing 10b of the tip dresser 10, respectively, and the central axes of the electrode tips 11 are brought into alignment with the rotation axis C1.

[0040] The drive motor and the gear meshing mechanism of the tip dresser 10 that are not shown are then driven in rotation to turn the cutter 1 on the rotation axis C1.

[0041] Thereafter, the electrode tips 11 are brought into proximity along the rotation axis C1 to the respective fitting surfaces 5c of the rotary holder 5 and the distal ends 11a of the electrode tips 11 are then fitted into the respective fitting surfaces 5c. As illustrated in FIG. 5, the cutting blade portions 2d of the cutter plate 2 thus contact the respective distal ends 11a of the electrode tips 11 to start to cut the distal ends 11a. In the operation, regions of the distal ends 11a of the electrode tips 11 immediately after cutting by the cutting blade portions 2d of the cutter plate 2 come into contact with the peripheral edges of the opening portions of the recessed grooves 2e that are formed on the flank faces 2b. The peripheral edges of the opening portion of the recessed grooves 2e then catch the distal ends 11a of the electrode tips 11 in a direction intersecting with the central axes, and guide the rotation on the distal ends 11a of the electrode tips 11. During the cutting operation, misalignment of the rotation axis C1 of the rotary holder 5 and the central axes of the electrode tips 11 thus can be prevented to stabilize the cutting operation.

[0042] The recessed grooves 2e are then formed on the flank faces 2b of the cutter plate 2 which has a smaller area than the fitting surface 5c of the rotary holder 5, enabling simpler machining and lower production cost as compared with WO2017/094041.

[0043] Moreover, the recessed grooves 2e are formed on the cutter plate 2 having the cutting blade portions 2d, so that after repeated cutting operations, the cutter plate 2 is removed from the rotary holder 5 for maintenance and thereby, the maintenance for the cutting blade portions 2d and the recessed grooves 2e can be simultaneously performed. Thus, less labor for maintenance is required as compared with a cutter 1 having the structure as described in WO2017/094041.

[0044] In addition, the recessed grooves 2e formed on the flank faces 2b are sloped to have a depth presenting a gentle increase as the recessed grooves 2e extend away from the respective cutting blade portions 2d, so that the recessed grooves 2e can be formed on the flank faces 2b without reduced thickness around the cutting blade portions 2d of the cutter plate 2. In the cutting operation, prevention of misalignment of the electrode tips 11 with the rotary holder 5 thus can be ensured, and higher rigidity around the cutting blade portions 2d also can be achieved to ensure prevention of chipping on the cutting blade portions 2d.

[0045] In this respect, when the cutting operation is performed by using the cutter 1 according to the present disclosure, concentric annular grooves are formed on distal ends 11a of electrode tips 11 by the peripheral edges of the opening portions of the recessed grooves 2e and a surface having protrusions and depressions are then formed on the distal ends 11a of the electrode tips 11. The depth of the annular grooves is small and thus this does not affect the welding.

[0046] In the embodiments of the present disclosure, the pair of cutting blade portions 2d are formed on the cutter plate 2; however, the embodiments are not limited to this configuration and either one of the cutting blade portions 2d may be only provided.

[0047] In the embodiments of the present disclosure, the recessed grooves 2e each have a generally V-shaped cross section; however, the embodiments are not limited to this configuration and the recessed grooves 2e each may have a curved shape.

[0048] In the embodiments of the present disclosure, the recessed grooves 2e are each sloped, but do not necessarily need to be sloped.

[0049] The present disclosure is suitable for a tip dressing cutter for use in cutting a distal end of an electrode tip of spot welding.