JP4140505B2 - Cutter holder and chip dresser device having the same - Google Patents

Description

  The present invention relates to a tip dresser device for cutting an electrode tip used for resistance welding or the like, and more particularly to a cutter holder provided therein.

  Conventionally, spot welding, which is one of resistance welding means, is performed using a welding robot or the like, and a metal welded portion is sandwiched between a pair of electrode tips attached to the ends of two arms. Done. The tip shape of the electrode tip gradually becomes flat each time it is used, and the welding quality becomes unstable as the number of hit points increases. Therefore, the tip portion of the electrode tip is periodically cut every predetermined number of hit points. This cutting is performed using a chip dresser device (see, for example, Patent Document 1).

  Exemplifying the configuration of the tip dresser device, a motor that outputs rotational driving force, a gear group that transmits the output of the motor by decelerating, and a cutter holder that includes a cutter and rotates by the rotational driving force transmitted through the gear group It is equipped with. The cutter holder has recesses on both the upper and lower surfaces for receiving the electrode tip and contacting the cutter.

  Usually, the cutter holder is set so that it can be removed from the chip dresser device for the purpose of performing maintenance such as replacement work and cleaning of the cutter. That is, the mode of providing the cutter holder can be roughly divided into two types. As the first mode, the final gear itself that is the end of the power transmission path of the gear group is also functioned as the cutter holder ( For example, see Patent Document 2). As a second aspect, a cutter holder prepared separately from the gear is detachably fitted to the corresponding gear (for example, see Patent Documents 1, 3 and 4). Of these, in the second embodiment, since the machining is easy, the outer shape of the cutter holder is often made symmetrical with no step in the vertical direction. In addition, such a fitting structure not only has excellent maintainability, but also slidably fits between the cutter holder and the gear so that when the electrode tip is contacted from both the top and bottom directions, the position in the vertical direction is related. There is also an advantage that some errors can be absorbed.

JP 2001-287046 A JP 11-47953 A JP 2000-52056 A JP 2002-292472 A

  Among the above-mentioned second aspects, the one disclosed in Patent Document 1 is a fitting form between the cutter holder and the gear, and the outer shape of the cutter holder is made square in plan view for driving force transmission. The concave portion of the gear to be accommodated is also a corresponding square hole. In addition, a hollow portion is formed in the center portion of the cutter holder in order to secure a cutter mounting space and promote discharge of cutting waste. As described above, since the meat at the center of the cutter holder is removed as a cavity, there is a problem that processing based on the center cannot be performed and suitable processing accuracy cannot be obtained. In addition, since the cutter holder has a square shape in plan view, it is difficult to ensure processing accuracy with reference to the outer shape.

  Furthermore, as disclosed in Patent Documents 3 and 4, a structure in which the entire outer shape of the cutter holder is circular in plan view has been proposed. With such a structure, the processing reference can be placed at the center of the circle by using a circular portion when manufacturing and processing the cutter holder, and higher processing accuracy can be obtained compared to the case of the square cutter holder. However, in the case of a circular cutter holder in plan view, due to the necessity of transmitting the driving force between the cutter holder and the gear, it is necessary to create an interlocking portion between the cutter holder and the gear by processing such as cutting out a part of the outer shape of the cutter holder. However, such processing causes another problem as follows. That is, between the cutter holder and the gear, in order to prevent unnecessary rattling at the time of cutting, it is preferable that a driving force that is equally uniform and symmetrical acts on the outer peripheral surface of the cutter holder. Therefore, in the case of a cutter holder having a circular shape in plan view as in the above-mentioned Patent Documents 3 and 4, in order to ensure the uniformity and symmetry described above, it is necessary to form a relatively large number of notches, which complicates processing. There is.

  Furthermore, as described above, when the cutter holder has a symmetrical shape with no step in the vertical direction, it is difficult to distinguish between the upper and lower sides of the cutter holder, and it may happen that the cutter holder is inserted upside down when set on the gear. . In addition, in order to prevent this, extra time and attention are required, such as attaching a mark only for upper and lower identification.

  The present invention has been made to cope with such various problems, and can easily perform high-precision processing at the time of manufacture, and can reliably prevent misplacement in the vertical direction while having a vertically symmetrical shape. An object of the present invention is to provide a cutter holder that can be used and a chip dresser device including the cutter holder.

In order to achieve the above-described object, the cutter holder of the present invention includes a holder body having a symmetrical outer peripheral portion including a circular portion in plan view, cutter means attached to the holder main body for cutting an electrode tip, and the outer peripheral portion. The concave and convex means for receiving the driving force provided at a position deviated from the left and right symmetry axis, the notch portion having a linear shape in plan view provided on the outer peripheral portion, and the holder body so that the cutter means performs cutting. And a keyway for receiving the concavo-convex means provided on the substantially opposite side of the end portion of the notch portion positioned in the rotation direction when the lens rotates forward .

Preferably, prior to symmetry axis of Kigai peripheral portion is also the axis of symmetry of the notch. Preferably, a first hollow portion is provided at the center of rotation of the holder body and on the front side of the cutter means during forward rotation of the holder body.

  Further, the cutter means is provided so as to be able to come into contact with the electrode tip both during forward rotation and reverse rotation of the holder body, and is a rotation center portion of the holder body, and when the holder body reverses in the cutter means. A second cavity portion may be provided on the front side of the first cavity portion, and the first cavity portion and the second cavity portion may be provided symmetrically.

  Preferably, the upper surface and the lower surface of the holder body and the cutter means are formed flush with each other.

  In order to achieve the same object, a chip dresser device according to the present invention includes the above-described cutter holder.

  According to the present invention, by using the circular portion in plan view provided on the outer peripheral portion of the cutter holder, it is possible to perform centering required as a processing reference and to facilitate manufacture. Therefore, high processing accuracy that satisfies the requirements can be ensured, and processing time can be shortened. In addition, the concave and convex means for receiving the driving force is provided at a position deviated from the left-right symmetrical axis on the outer periphery of the cutter holder. Can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically and schematically shows a configuration of a chip dresser device according to the present embodiment. The tip dresser device 21 mainly includes a cutter holder 23 having a cutter for cutting an electrode tip, a three-phase AC motor 25 as a driving means thereof, and a rotation provided between the three-phase AC motor 25 and the cutter holder 23. And a force transmission mechanism 27.

  The three-phase AC motor 25 is connected to a three-phase AC power source 37 (using 200 V in this embodiment) via a thermal relay 33 and a forward / reverse switching circuit 35. The thermal relay 33 prevents the three-phase AC motor 25 from being damaged by cutting off the power supply to the three-phase AC motor 25 when an excessive load is applied to the cutter holder 23 during cutting. In addition, the forward / reverse switching circuit 35 rotates the cutter holder 23 forward for a predetermined time to perform cutting as will be described later, reverses the cutter holder 23 for a predetermined time to promote removal of cutting waste, and alternates forward rotation and reverse rotation. The current supply to the three-phase AC motor 25 is controlled as shown in FIG.

  The rotational force transmission mechanism 27 includes a pair of bevel gears 43 and 45. One bevel gear 43 is connected to the output shaft of the three-phase AC motor 25. The other bevel gear 45 has a hole for accommodating the cutter holder 23 at the center thereof. That is, the cutter holder 23 is accommodated in the bevel gear 45 and rotates integrally with the bevel gear 45.

  Next, details of the cutter holder 23 will be described with reference to FIGS. 1, 2, and 3. Note that the directions used in the description in the figure are determined based on the upper side in FIG. 1, the upper side in FIG. 2, and the upper side in FIG. 3. The cutter holder 23 includes a holder main body 61, a cutter 63 as a cutter means, and a key 65 as an uneven means. The holder main body 61 has an outer peripheral portion 67 including an arcuate curved surface portion 67a having a circular shape in plan view and a chordal flat portion 67b having a straight line in plan view as a notch portion. The outer peripheral part 67 is configured symmetrically in plan view with respect to the symmetry axis SA. Therefore, the symmetry axis SA is also the symmetry axis of the chordal plane portion 67b itself. The chordal plane portion 67b is formed so as to cut off an arc-shaped portion (portion indicated by a dotted line in FIG. 2) in one direction with respect to a single-radius cylinder including the arc-shaped curved surface portion 67a.

  The holder main body 61 is formed with a first cavity 69 that penetrates from the upper surface to the lower surface. The first cavity 69 includes a columnar portion 69 a located at the rotation center including the rotation axis TA of the holder main body 61, a cutter accommodating portion 69 b serving as a space for accommodating the cutter 63, and the normal rotation direction of the holder main body 61. And a fan-shaped portion 69c located on the front side of the FD. With the first cavity 69 having such a configuration, the cutter 63 is accommodated in a proper position, and the removal of cutting waste is promoted when the holder body 61 described later is reversed.

  Further, a pair of upper and lower mortar-shaped recesses 71 are formed at the rotation center of the holder body 61. Each mortar-shaped recess 71 is formed in such a direction that the opening expands toward the upper surface 61 a and the lower surface 61 b of the corresponding holder body 61. The cutting part 63a of the cutter 63 is disposed on the slope defining the mortar-shaped recess 71, and has a shape corresponding to the target cutting shape of the electrode tip 15 indicated by a two-dot chain line in FIG. The electrode tip 15 is cut by the contact of the cutting portion 63 a of the cutter 63 while being held in the mortar-shaped recess 71.

  In addition, a key groove 73 is formed on the outer peripheral portion 67 of the holder main body 61 to receive the key 65 and to form a concave / convex means for receiving a driving force together with the key 65. The key groove 73 and the key 65 attached to the key groove 73 are provided not on the left-right symmetric axis SA of the outer peripheral portion 67 but at a position deviated from the axis. The axis A of the key groove 73 and the key 65 is shifted by a predetermined value S parallel to a radial line R (which forms a predetermined angle X with the symmetry axis SA) connecting the rotation axis TA and the outer peripheral portion 67. Although not shown in the drawings, when the cutter holder 23 is put into the bevel gear 45, the receiving surface of the bevel gear 45 is formed with a key groove that can receive the protruding portion of the key 65 corresponding to the key groove 73. It shall be.

  Further, a circular through hole 75 penetrating from the outer surface to the fan-shaped portion 69 c is formed in the outer peripheral portion 67 of the holder main body 61. Such a through-hole 75 allows the tool for rotating the screw 77 to access the screw 77 from the outer surface of the outer peripheral portion 67 through the fan-shaped portion 69 c when the cutter 63 is fixed to the holder body 61 using the screw 77 or removed. Allow to do. Further, when the cutter 63 is attached to the holder main body 61, the upper surface 61a of the holder main body 61 and the upper surface 63c of the cutter 63, and the lower surface 61b of the holder main body 61 and the lower surface 63b of the cutter 63 are aligned with each other. It is configured.

  Next, the operation of the chip dresser device of the present embodiment configured as described above will be described. The three-phase AC motor 25 is rotated at 1800 rpm by the current provided by the three-phase AC power source 37. The gear ratio of the bevel gears 43 and 45 is selected to be 1/2, and the cutter holder 23 is driven to rotate at 900 rpm by the rotation of the three-phase AC motor 25 described above. Also, the pair of upper and lower electrode tips 15 attached to the tips of the pair of upper and lower shanks 57 of the welding gun are pressed against the corresponding mortar-shaped recesses 71 respectively. Thus, the pair of electrode tips 15 is cut by the cutter 63 of the rotating cutter holder 23 and processed into a tip shape that can provide a predetermined welding quality. In the present embodiment, the three-phase AC motor 25, the cutter holder 23, etc., as shown in FIG. 4, rotate forward for 0.5 seconds, then stop for 0.1 seconds, and further reverse for 0.1 seconds. It operates in a cycle in which normal rotation is performed again after stopping for 0.1 second. That is, the cutter holder 23 cuts the electrode tip 15 at the time of normal rotation for 0.5 seconds, and promotes the removal of the cutting waste from the electrode tip 15 at the time of reverse rotation of 0.1 seconds. In this way, by rotating the cutter holder 23 so as to repeat normal rotation and reverse rotation, the electrode tip 15 is cut into a target shape while removing cutting waste.

  Further, the cutter holder 23 of the present embodiment has the following operation. First, since the cutter holder 23 has an outer peripheral portion 67 including a circular arc-shaped curved portion 67a having a circular shape in plan view, the arc-shaped curved surface portion 67a can be used to perform centering necessary as a processing standard and easy to manufacture. Become. In particular, even with a structure in which a hollow portion is formed in the center and no meat exists, centering based on the processing standard can be performed. Therefore, the required high processing accuracy can be ensured and the processing time can be shortened. Further, since the outer peripheral portion 67 of the holder main body 61 is similar to the mortar-shaped concave portion 71 having a circular shape in plan view, the cutter holder 23 can be made compact and can be easily applied to various welding guns and electrode tips. It is. Further, the cutter holder 23 is formed with only one notch portion (string-like plane portion 67b) for transmitting the driving force, but the key groove 73 is provided on the substantially opposite side of the notch portion (string-like plane portion 67b). Is arranged. At the time of normal rotation for cutting, that is, when rotating in the FD direction shown in FIG. 2, a force stronger than the bevel gear 45 acts on the right end of the chordal plane portion 67b, that is, the end located in the rotational direction. Since the key 65 is arranged on the opposite side, the driving force acts on the outer peripheral surface of the holder body almost evenly. Therefore, unnecessary play does not occur between the cutter holder 23 and the bevel gear 45 during cutting. Further, even if the cutter holder 23 is configured so as to be bilaterally symmetric, the key 65 is provided at a position deviated from the bilaterally symmetric axis. It is possible to surely prevent an upside-down error.

  Next, a cutter holder according to another embodiment of the present invention will be described with reference to FIG. In addition, this Embodiment shall be the same as that of the structure of the said embodiment shown in FIGS. 1-3 except the part demonstrated below. The cutter holder 123 includes a holder main body 161, a cutter 163 as a cutter means, and a key 65. The holder main body 161 is formed with a first cavity portion 169 and a second cavity portion 269 that penetrate from the upper surface to the lower surface. The first cavity 169 is positioned on the front side of the forward rotation direction FD of the holder main body 61, the cylindrical portion 169a located at the rotation center, the cutter accommodating portion 169b serving as a space for accommodating the right half of the cutter 163, and the like. Fan-shaped portion 169c. With the first cavity 169 having such a configuration, the cutter 163 is accommodated in an appropriate position, and the removal of cutting waste is promoted when the holder body 61 described later is reversed. The second cavity portion 269 has the same action as the first cavity portion 169, and includes a columnar portion 169 a that is also a component of the first cavity portion 169, and a space that accommodates the left half of the cutter 163. And a fan-shaped portion 269c located on the front side of the holder main body 61 in the reverse rotation direction RD.

  In addition, a pair of upper and lower mortar-shaped recesses 171 are formed at the rotation center of the holder body 161. Each mortar-shaped recess 171 is formed in such a direction that the opening expands toward the upper and lower surfaces of the corresponding holder body 161.

  Further, the outer peripheral portion 67 of the holder main body 161 is formed with a key groove 173 that receives the key 65 and forms an uneven means for receiving a driving force together with the key 65. The key line 173 and the axis A of the key 65 attached to the key groove 173 are not on the left-right symmetric axis SA of the outer peripheral portion 67 but are provided at positions offset in parallel by a predetermined value S ′ from the axis.

  Further, a pair of circular left and right through holes 175 penetrating from the outer surface to the left and right fan-shaped portions 169 c and 269 c are formed in the outer peripheral portion 67 of the holder main body 161. The through hole 175 has the same action as the through hole 57, and allows the screw for fixing the cutter 163 to be tightened or loosened from the outside of the outer peripheral portion 67 via the corresponding fan-shaped portions 169c and 269c. . Further, when the cutter 163 is attached to the holder main body 161, the upper surface of the holder main body 161 and the upper surface of the cutter 163, and the lower surface of the holder main body 161 and the lower surface of the cutter 163 are configured to be flush with each other. .

  Also in the present embodiment having such a configuration, the following actions are obtained as in the embodiment shown in FIGS. That is, the cutter holder 123 uses the arcuate curved surface portion 67a, so that it can be centered as a processing reference and can be easily manufactured. Further, since the outer peripheral portion 67 of the holder main body 161 is similar to the mortar-shaped concave portion 171 having a circular shape in plan view, the cutter holder 123 can be made compact. The cutter holder 123 has only one notch (string-like flat portion 67b). Since the key groove 173 is disposed on the substantially opposite side of the notch, the outer peripheral surface of the holder main body 161 is provided. A uniform and symmetrical driving force acts on the, and no unnecessary rattling occurs. Further, even if the cutter holder 123 is configured so as to be bilaterally symmetrical, the key 65 is provided at a position deviated from the bilaterally symmetric axis, so that there is no need to provide a means dedicated to vertical identification such as steps and marks. It is possible to surely prevent an upside-down error. Further, the cutter 163 in the present embodiment is configured and arranged so as to be able to contact the electrode tip 15 both when the holder body 161 is rotated forward and when it is rotated backward. Therefore, the electrode tip 15 can be cut using the left half of the cutter 163 even during reverse rotation.

The present invention described above is not limited to the above-described embodiment, and can be implemented with various modifications. For example, the cutter means is not limited to being made of one cutter, and may be made of a plurality of cutters.
Moreover, the notch part provided in the outer peripheral part of the holder main body is not limited to a planar view linear shape as shown in FIG. In other words, the cutout portion and the other portion may be in other forms as long as the curvature or the surface extension direction is different and the rotation drive force can be transmitted between the holder body and the bevel gear. For example, the cutout portion may be formed of a gently curved surface having a smaller radius of curvature than the arcuate curved surface portion 67a.
In addition, the uneven means is not limited to an aspect composed of a key and a key groove, and may be configured differently from the above-described embodiment as long as the rotational driving force can be transmitted by engaging in an uneven relation. Good. For example, you may be comprised from the protrusion extended toward a radial direction outward from a holder main body. Alternatively, on the contrary, a projection may be provided on the inner surface side of the receiving hole of the bevel gear that receives the cutter holder, and the holder main body may be provided with a groove that engages with the projection.

It is a figure which shows the structure of the chip dresser apparatus which concerns on embodiment of this invention. It is a top view of the cutter holder in the chip dresser apparatus of FIG. It is a side view of the cutter holder of FIG. It is a graph which shows a normal / reverse state regarding rotation of the cutter holder in a chip dresser device. It is a figure of the same aspect as FIG. 2 regarding other embodiment.

Explanation of symbols

  15 Electrode tip, 21 Tip dresser device, 23 Cutter holder, 61 Holder body, 63 Cutter (cutter means), 65 Key (unevenness means), 67 Outer peripheral part, 67b Stringed flat part (notch part), 69,169 1st Cavity, 269 Second Cavity, SA Symmetry axis.

Claims (6)

A holder body having a symmetrical outer periphery including a circular portion in plan view;
A cutter means attached to the holder body for cutting the electrode tip;
Concavity and convexity means for receiving a driving force provided at a position deviated from the left-right symmetry axis of the outer peripheral portion ,
A notch portion in a straight line in plan view provided on the outer peripheral portion;
A keyway for receiving the concavo-convex means provided on the substantially opposite side of the end of the notch located in the direction of rotation when the holder body rotates forward so that the cutter means performs cutting. > Cutter holder characterized by comprising Cutter holder as claimed in claim 1 in which the symmetry axis of the front Kigai peripheral portion, characterized in that also the axis of symmetry of the notch.   3. The cutter holder according to claim 1, wherein a first cavity portion is provided at a rotation center portion of the holder main body and on a front side of the cutter means when the holder main body is normally rotated. The cutter means is provided so as to be able to contact the electrode tip both during forward rotation and reverse rotation of the holder body,
A second hollow portion is provided at the center of rotation of the holder body, on the front side when the holder body is reversed in the cutter means,
The cutter holder according to any one of claims 1 to 3, wherein the first cavity part and the second cavity part are provided line-symmetrically.   5. The cutter holder according to claim 1, wherein an upper surface and a lower surface of the holder main body and the cutter means are formed flush with each other.   A chip dresser device comprising the cutter holder according to claim 1.

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