JPH11320271A - Electrode feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously perform high precision working based upon a generating electric discharge machining. SOLUTION: A feeding means 4 for an electrode 2 has a spool 10 and a sleeve 11. Male threads 10a are formed at the peripheral surface of the spool 10 while female threads are formed at the inside surface of the sleeve 11. The male threads 10a are furnished with a non-thread portion 10b where the threads are removed in a straight line to the payoff direction of the electrode 2. In the same manner, the female threads on the sleeve 11 are furnished with a non-thread portion with the threads removed in a straight line to the payoff direction of the electrode 2. In the condition that the two sorts of threads are in engagement, a clamp 9 supported by the spool 10 fastens the electrode 2 and moves in the payoff direction of the electrode. In the condition that the non-thread portion of one member is mating with the threaded portion of the other member, the clamp 9 releases the electrode 2 and moves temporarily in the opposite direction to the payoff direction. This operating cycle is repeated so that the electrode 2 is paid off continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode feeding device for an electric discharge machine.

[0002]

2. Description of the Related Art Conventionally, an electric discharge machining method has been used as a method for processing a die such as a forging die, a die casting die, a plastic molding die or the like. EDM requires easy processing of high-hardness / tough metal materials such as hardened steel and cemented carbide, easy processing of complex shapes, high processing accuracy, and low working force during processing. There are advantages such as easy automation and economy. In the case of very common electric discharge machining, the shape of the electrode, which is a tool, is the inverse of the shape of the machining part, and in general, twice the sum of the machining gap, machining surface roughness, and finishing margin from the desired machining finish dimensions. It is formed on the basis of the difference.

Further, a so-called electric discharge machining method has come to be used as an electric discharge machining method which does not require an electrode having the shape of the machining portion inverted. In the electric discharge machining method, a desired product shape is obtained by rotating and moving a rod-shaped or pipe-shaped electrode in place of an end mill in the same manner as the end mill. According to this method, the step of transferring the shape of the processed portion to the electrode is not required, so that it is possible to reduce the number of days for manufacturing the mold and the like, and it is possible to maintain the processing accuracy at a high level. There is an advantage.

[0004]

The electrodes used in the above-mentioned electric discharge machining have a small cross-sectional area compared to the removal amount of the workpiece, so that the consumption of the electrodes cannot be avoided. Therefore, after using the electrode for a certain period of time, A
It was necessary to replace using TC (Auto Tool Change) or the like. However, the time required for electrode replacement has caused a reduction in the operation rate of the apparatus. Therefore, in order to reduce the replacement time as much as possible, a method of giving the electrodes a sufficient length in advance and extending the electrodes in accordance with the consumption rate of the electrodes has been adopted. JP-A-2-37725
In Japanese Patent Application Publication No. JP-A-2006-133, an electrode feeding device that can be used for the electric discharge machining is described.

By the way, in the electric discharge machining, the wear of the electrode occurs continuously, and in order to compensate for the consumption, it is ideal to give the electrode a continuous feeding corresponding to the wear rate. is there. However, the conventional electrode feeding means does not meet this requirement, and it has been difficult to continuously process.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an electrode feeder capable of continuously feeding out a long electrode and capable of freely adjusting the feeding speed. An object of the present invention is to provide a device and continuously perform high-precision machining by generating electric discharge machining.

[0007]

According to the present invention, there is provided a storage means capable of accommodating a plurality of electrodes and sending out the electrodes one by one, and an electrode fed from the storage means. , A rotary driving means for rotating the fed electrode, and a working fluid supply means for supplying a working fluid to the surface to be processed together with the electrode.

[0008] According to the above configuration, by storing a plurality of electrodes in the storage means and sending them out one by one from the storage means, it is possible to continuously supply the electrodes. Further, the electrode sent from the storage means in the feeding means,
By feeding continuously at an arbitrary speed, the feeding of the electrode corresponding to the continuous consumption of the electrode is performed. Then, the electrode is rotated by the rotation driving means, and
The electric discharge machining is performed by supplying the machining fluid to the surface to be machined by the machining fluid supply means.

Further, in the present invention, the feeding means includes:
It has a clamp provided in series with the electrode feeding direction of the storage means, and displaces the clamp at an arbitrary speed in the feeding direction of the electrode in a state where the electrode is tightened, or A drive mechanism for temporarily displacing in a direction opposite to the feeding direction in a state where the tightening is released is provided.

The electrode feeding means displaces the electrode in a direction in which the electrode is extended in a state where the electrode is tightened by the clamp. At this time, the dispensing speed of the electrode can be freely set by arbitrarily adjusting the displacement speed of the clamp in the electrode dispensing direction. Further, by displacing the electrode in the direction opposite to the extending direction in a state where the clamp is released by the clamp, only the clamp returns to the original position without changing the position of the extended electrode. At this time, since the clamp is returned at one time, continuity of feeding of the electrode can be ensured.

Further, in the present invention, the driving mechanism includes:
It has a cylindrical member that holds the clamp so that it can be opened and closed, and a support member that rotatably supports the cylindrical member, wherein the cylindrical member and the support member rotate the cylindrical member with respect to the support member at a predetermined angle. A first cam assembly that repeats a process of tightening the clamp during the interval and releasing the clamp when the predetermined angle is exceeded, and a rotation of the cylindrical member with respect to the support member during the predetermined angle,
Moving the cylindrical member in the payout direction at a constant speed relative to the support member, and moving the cylindrical member relative to the support member at a time after the rotation of the predetermined angle in a direction opposite to the payout direction. And a second cam assembly that repeats.

According to the above construction, when the rotation angle of the cylindrical member with respect to the support member is a predetermined angle, the clamp is tightened, and the cylindrical member is moved at a constant speed with respect to the support member in the extending direction. The electrode is fed at a predetermined speed. At this time, the feeding speed of the electrode is adjusted by adjusting the rotation speed of the cylindrical member. Further, when the rotation angle of the cylindrical member with respect to the support member exceeds a predetermined angle, the clamp is released, and the cylindrical member is temporarily moved relative to the support member in a direction opposite to the extending direction. Then, only the clamp is returned to the original position without changing the position of the extended electrode. At this time, since the clamp is returned at one time, continuity of feeding of the electrode can be ensured.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a main shaft 1 of an electrode feeding device according to an embodiment of the present invention. This spindle 1 is mainly
Positioning is performed by a method similar to that of a machine tool such as a machining center that operates in the axis (XYZ axis) direction. Inside the main shaft 1, a plurality of rod-shaped or pipe-shaped electrodes 2 are accommodated, and storage means 3 capable of sending out one by one, and electrodes 2 sent out from the storage means 3 are continuously fed at an arbitrary speed. The feeding means 4 for feeding out is arranged in series. An electrode guide 5 is provided between the storing means 3 and the feeding means 4. An electrode guide 6 is also provided below the feeding means 4. A portion indicated by reference numeral 7 is a power supply unit. Then, a rotation drive means (not shown) for rotating the main shaft 1 in the direction of arrow A is provided. Further, the storage means 3 is connected to a processing liquid supply means 8 capable of supplying a processing liquid to the storage means 3 even while the main shaft 1 is rotating. The electrode 2 is
It passes through the electrode guide 5, the feeding means 4, and the electrode guide 6, and protrudes from the tip of the main shaft 1 by a predetermined length. Then, the electric discharge machining is performed on the work surface of the work W. The processing liquid supplied to the storage means 3 is supplied to the surface to be processed of the work W together with the electrode 2.

Hereinafter, the structure of each part of the electrode supply device will be described in more detail. The storage means 3 has a cylindrical shape as shown in FIG. 1, and the bottom surface 2a is formed in a conical shape. A hole through which only one electrode 2 can pass is formed in the center of the bottom surface 2a. Since the bottom surface 2a has a conical shape, the plurality of electrodes 2 stored therein naturally gather at the center of the bottom surface 2a and pass through the holes one by one. In order to guide the electrodes 2 one by one to the holes one by one, the bottom surface 2a may be provided with a spiral shape or a groove extending radially from the hole. Further, if the inside of the storage means 3 is divided by a wall surface, different types of electrodes are loaded in each section, and if necessary, the type of the electrode to be dropped into the hole in the bottom surface 2a is selected, the different types of electrodes can be selected. It is easy to properly use the electrodes.

FIG. 2 schematically shows the supply means 4. FIG. 3 is a sectional view taken along line BB of FIG. 2, and FIG. 4 is a sectional view taken along line CC of FIG. An electrode guide 5 is located above the supply means 4, and an electrode guide 6 is located below the supply means. The supply means 4 includes a clamp 9 in series with the electrode feeding direction of the storage means 3 (the direction from the upper side to the lower side in FIG. 2). Clamp 9
Is composed of several holding members as shown in FIGS. 2 and 4, and clamps the electrode 2 from the periphery thereof. or,
The clamp 9 is displaced at an arbitrary speed in the feeding direction of the electrode 2 in a state where the electrode 2 is tightened, or is temporarily displaced in a direction opposite to the feeding direction in a state where the tightening of the electrode 2 is released. It has a mechanism.

The drive mechanism has a spool 10 (cylindrical member) for holding the clamp 9 so that it can be opened and closed, and a sleeve 11 (support member) for rotatably supporting the spool 10. An external thread 10a is formed on the outer peripheral surface of the spool 10, and the sleeve 11
Is formed on the inner peripheral surface thereof and is screwed together. The male screw 10a of the spool 10 has a non-threaded portion 10b in which the thread is removed in a straight line in the extension direction of the electrode 2.
However, there are several places. The internal thread 11 of the sleeve 11
The non-threaded portion 11b in which the thread is removed in a straight line in the extension direction of the electrode 2 is also provided in a. As shown in FIG. 3, the width E ₁ of the non-threaded portion 10 b of the spool 10 is wider than the width E _{2 of} a portion other than the non-threaded portion 11 b of the female screw 11 a of the sleeve 11 (the portion having a thread). Is formed. The non-threaded portion 11b of the sleeve 11 is also
It is formed wider than the part other than the non-threaded part (the part with a thread). Therefore, as shown in FIG. 3, in a state where the non-threaded portion and the portion having the thread coincide with each other, the screwed state between the male screw 10a of the spool 10 and the female screw 11a of the sleeve 11 is completely released, and the spool 10 It is possible to move the sleeve 11 in the electrode feeding direction at a time.

A case 12 for covering the clamp 9 held openably and closably by the spool 10 is fixed to the sleeve 11. Further, an urging means 13 such as a coil spring for urging the spool 10 together with the clamp 9 in a direction opposite to the electrode feeding direction (from the lower side to the upper side in FIG. 2) is provided. When the threads of the spool 10 and the sleeve 11 are engaged with each other, the spool 10 rotates in the electrode 11 by rotating the spool 10 with respect to the sleeve 11. At this time, the coil spring 13 contracts and stores elastic force.
When the non-threaded portion and the threaded portion coincide with each other as shown in FIG. 3, the spool 10 moves at once to the sleeve 11 in the direction opposite to the electrode feeding direction by the elastic force of the coil spring 13. And can be moved.

Further, a driven gear 14 is fixed to the spool 10. Further, the driven gear 14 meshes with the drive gear 15. The drive gear 15 is driven by a power source such as a servomotor that can accurately control the number of rotations and the rotation speed. As described above, the spool 10 moves in the vertical direction of FIG. 2 with respect to the sleeve 11, and during this time, the driving gear 15 extends the operating range of the driven gear 14 so that the driven gear 14 and the driving gear 15 always mesh. It is a gear with a wide tooth width that takes into account.

As described above, while the rotation of the spool 10 with respect to the sleeve 11 is at a predetermined angle (while the male screw 10a and the female screw 11a are screwed together), the male screw 10a is guided by the female screw 11a with the rotation, and It moves in the electrode extension direction at a speed. The amount of movement of the spool 10 with respect to the rotation angle is determined by the pitch of the screw. Therefore, control of the amount of movement of the spool 10 is easy. When the rotation of the spool 10 with respect to the sleeve 11 is larger than the predetermined angle, as shown in FIG. 3, the non-threaded portion and the threaded portion are aligned with each other.
The elastic force of the coil spring 13 causes the sleeve 11 to move at a time in a direction opposite to the electrode feeding direction. Therefore, if the spool 10 continues to rotate with respect to the sleeve 11, the clamp 9 repeats the process of moving at a constant speed in the electrode feeding direction and the process of temporarily moving in the direction opposite to the electrode feeding direction. . The spool 10, the male thread 10a, and the non-threaded part 10 which generate these two strokes in the clamp 9
b, the sleeve 11, the female screw 11a, the non-threaded portion 11b, the coil spring 13 and the like are collectively referred to as the second in the embodiment of the present invention.
It is called a cam assembly.

As described above, the clamp 9 is held on the spool 10 so as to be openable and closable. The clamp 9 is covered by a case 12 fixed below the sleeve 11. As shown in FIGS. 2 and 4, the case 12 has a sleeve 11 and a projection 16 fixed to the case 12. The clamp 9 comes into contact with the projection 16. The abutment surface 9a of the clamp 9 against the projection 16 has a cam profile (shape that determines cam characteristics) such that when the clamp 9 rotates together with the spool 10, the clamp 9 moves in the direction of tightening. Further, the clamps 9 are urged by elastic members 17 such as coil springs in a direction in which they are released from each other.

In the example shown in FIG. 4, when the spool 10, the clamp 9, and the coil spring 17 rotate counterclockwise with respect to the sleeve 11, the case 12, and the protrusion 16, the clamp 9 The shoulder 9b abuts and the abutment surface 9a
, Each clamp 9 moves in the direction of tightening the electrode 2. Then, when the spool 10 rotates to a position where the clamp 9 is disengaged from the projection 16, each clamp 9 loses the pressing action by the projection,
The elastic force of the coil spring 17 moves the electrode 2 in a direction to release the clamp 9.

As described above, the clamp 9 is tightened while the rotation of the spool 10 with respect to the sleeve 11 is at a predetermined angle (while the clamp 9 and the projection 16 are in contact with each other). When the rotation of the spool 10 with respect to the sleeve 11 exceeds the predetermined angle, the clamp 9 is disengaged from the projection 16 and the coil spring 17
The clamp 9 is released by the elastic force of. Therefore,
As the sushi spool 10 continues to rotate with respect to the sleeve 11, the clamp 9 repeats the tightening process and the releasing process. The contact surface 9a of the clamp 9, which causes the clamp 9 to generate these two strokes, the protrusion 16, the spool 10, and the sleeve 1
1, the coil spring 17 and the like are collectively referred to as a first cam assembly in the present invention.

Further, the clamp 9 by the first cam assembly is used.
And the stroke of moving the clamp 9 by the second cam assembly in the electrode feeding direction at a constant speed are synchronized, and the releasing stroke of the clamp 9 by the first cam assembly and the clamp 9 by the second cam assembly are synchronized. Are arranged so that the process of moving the electrode in the direction opposite to the electrode feeding direction is synchronized with the process of moving the electrode in the direction opposite to the electrode feeding direction. Desirably, the release timing of the clamp 9 is completed before the clamp 9 is moved in the direction opposite to the electrode feeding direction.

As shown in FIG. 5 (a), the electrode guide 5 has the narrowest central portion and the widest end portions.
a. As shown in FIG. 5B, the electrode guide 6 has a constant diameter (having substantially the same diameter as the electrode 2) having a chamfer formed at one end (the end facing the feeding means 4). It has an insertion passage 6a. The main shaft 1 is inserted into the electrode insertion passages 5a and 6a while suppressing frictional resistance when the electrode 2 passes.
It is required to prevent the electrode 2 from swinging when the electrode 2 rotates with the rotation of the electrode 2. Therefore, in the present embodiment,
An electrode insertion passage 5a having less frictional resistance is used for the electrode guide 5 far from the work surface, and an electrode insertion passage 6a having a large effect of suppressing electrode deflection is used for the electrode guide 6 close to the work surface. doing.

If the electrode guides 5 and 6 are detachable, it is easy to replace the electrode guide with an electrode guide corresponding to an arbitrary electrode diameter. Further, FIG. 9 exemplifies electrode guides 5 and 6 that change the diameter of the electrode insertion passages 5a and 6a. FIG. 9A is a top view of the electrode guides 5 and 6,
FIG. 9B is a cross-sectional view of the electrode guide 5, and FIG. 9C is a cross-sectional view of the electrode guide 6. In this example, a plurality of guide members 24 extending in the electrode feeding direction are supported by springs 25 in a cylindrical case 23. That is, each guide member 24 forms the electrode insertion passages 5a and 6a. Since each guide member 24 is displaced according to the diameter of the passing electrode, the diameter of the electrode insertion passages 5a and 6a can be freely changed. FIG. 10 shows electrode guides 5 and 6 made of an elastic material such as rubber. FIG. 10A is a top view of the electrode guides 5 and 6, and FIG. 10B is a sectional view thereof. In this example, the material of the electrode guides 5 and 6 is an elastic body such as rubber, and forms a mortar-shaped wall surface 27 having a slit 26 therein. And the electrode insertion passage 5
When an electrode of an arbitrary diameter passes through a and 6a, the wall surface 27 is deformed according to the electrode diameter, and the diameter of the electrode insertion passages 5a and 6a can be freely changed.

The operation and effect obtained by the electrode feeding device according to the embodiment of the present invention having the above-described configuration are as follows. As described above, the storage means 3 can accommodate a plurality of electrodes 2 and send them out one by one. Further, in the feeding means 4, the tightening process of the clamp 9 by the first cam assembly and the process of moving the clamp 9 by the second cam assembly in the electrode feeding direction at a constant speed are synchronized. Therefore, the electrodes 2 fed one by one from the storage means 3 and supplied to the feeding means 4 via the electrode guide 5 are moved by the clamp 9 in the electrode feeding direction at a constant speed. Since the operation of the clamp 9 is caused by rotating the spool 10, the feeding speed of the electrode 2 can be freely adjusted by controlling the rotating speed of the spool 10. In addition, since the spool 10 is driven by a power source such as a servo motor, the control of the rotation speed is easy.

Further, the releasing step of the clamp 9 by the first cam assembly and the step of moving the clamp 9 by the second cam assembly in the direction opposite to the electrode feeding direction are synchronized. Only the clamp 9 can be returned to the original position without changing the position of the extended electrode 2. At this time, since the clamp 9 is returned at one time,
Ensures the continuity of electrode feeding. Therefore, the electrode feeding device according to the present embodiment can continuously feed out the electrode 2 and freely adjust the feeding speed. For this reason, it is possible to give a continuous feeding to the electrode corresponding to the consumption speed of the electrode 2 during the electric discharge machining, and it is possible to continuously perform high-precision machining by the electric discharge machining method.

Further, according to the electrode feeding device according to the present embodiment, the electrode 2 can be continuously fed and the feeding speed can be freely adjusted. It is also easy to control the length of the protrusion with high precision. Therefore, a desired product shape is formed by changing the length of the electrode 2 to be extended in place of the operation of the main shaft 1 in the depth direction (the Z-axis direction in FIG. 1) with respect to the non-processed surface of the work W. It is also possible. According to this method, it is possible to reduce the amount of operation of the spindle 1, which is a heavy object, and it is possible to further improve the positioning accuracy of the spindle 1.

According to the electrode feeding device according to the present embodiment, for example, a wire-shaped electrode can be used as the electrode 2, and in this case, the continuity of processing can be further improved. it can. In the present embodiment,
Although there is a rotation driving means for rotating the electrode 2 by rotating the main shaft 1 itself, it is also possible to fix the main shaft 1 itself and provide a rotation driving means for rotating the feeding means 4 therein.

FIGS. 6 to 8 show a first example of the feeding means 4.
Application examples of the cam assembly and the second cam assembly are disclosed. The first cam assembly shown in FIG. 6 contacts a rotating body 18 whose outer periphery has a cross-sectional shape whose diameter from the center gradually increases, such as an involute curve, so as to abut the inner side surface 12a of the case 12. In contact. And the case
With the rotation of 12, each rotating body 18 rotates. When the case 12 is rotated clockwise in FIG. 6, each rotating body 18 brings its surface 18 a closer to the electrode 2. When the case 12 is rotated counterclockwise, each rotator 18 separates its surface 18 a from the electrode 2. Therefore, each rotating body 18 functions as a clamp for holding the electrode 2. Further, the first cam assembly shown in FIG. 7 is provided with three links 19, 20, 21 so as to be rotatable with respect to the case 12;
20, 21 are combined. The space 22 surrounded by the links 19, 20, and 21 is expanded or reduced in accordance with the rotation of the case 12, and the electrodes are sandwiched. In addition, by adopting the structure shown in FIGS. 6 and 7 for the electrode guides 5 and 6, it is possible to provide an electrode guide that can correspond to an arbitrary electrode diameter. In this case, the storage means 3
It is assumed that the diameters of the electrode insertion passages of the electrode guides 5 and 6 are set in advance in accordance with the electrode diameter selected in the step (1).

Further, the second cam assembly shown in FIG.
Male thread 10a and non-threaded part 10b of spool 10 shown in FIG.
And in place of the internal thread 11a and the non-threaded portion 11b of the sleeve 11,
The spool 10 is provided with a groove 10c, and the sleeve 11 is provided with a follower 11c which engages with the groove 10c. The groove 10c is a single continuous groove formed on the outer peripheral surface of the spool 10 with a constant inclination and having a portion extending in the electrode supply direction. When the follower 11c provided on the sleeve 11 moves along the groove 10c, the spool 10 can perform the same operation as the example in FIG.

[0033]

According to the present invention, the following effects are obtained. First, according to the electrode feeding device according to claim 1 of the present invention, the plurality of electrodes housed in the storage means are fed by the feeding means at a speed corresponding to the continuous consumption of the electrodes generated during the electric discharge machining. , It is possible to feed out continuously. Then, the electrode is rotated by the rotation driving means, and, by supplying the machining fluid to the surface to be machined by the machining fluid supply means, the generation electric discharge machining continuously,
In addition, it can be performed with high accuracy.

According to the electrode supply device of the second aspect of the present invention, since the feeding of the electrodes in the feeding means can be continuously performed and the feeding speed can be freely set, the electric discharge machining can be performed. High-precision processing by the method
It can be performed continuously.

Further, according to the electrode feeding device according to the third aspect of the present invention, by adjusting the rotation speed of the cylindrical member with respect to the support member, the feeding of the electrode in the feeding means is continuously performed, In addition, the feeding speed can be set freely. Therefore, high-precision machining by the electric discharge machining method can be continuously performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main shaft of an electrode feeding device according to an embodiment of the present invention.

2A and 2B are a side view and a partial cross-sectional view showing a main shaft feeding unit shown in FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along line CC of FIG. 2;

FIG. 5 is a sectional view showing an electrode guide of the main shaft shown in FIG. 1;

FIG. 6 is a sectional view showing an application example of the first cam assembly of the main shaft feeding means shown in FIG. 1;

FIG. 7 is a sectional view showing an application example of the first cam assembly of the main shaft feeding means shown in FIG. 1;

8A and 8B are a side view and a partial cross-sectional view showing an application example of the second cam assembly of the main shaft feeding means shown in FIG.

9A and 9B are a top view and a sectional view showing an application example of the electrode guide shown in FIG.

10A and 10B are a top view and a cross-sectional view showing a further application example of the electrode guide shown in FIG.

[Explanation of symbols]

 2 Electrode 3 Storage means 4 Feeding means 9 Clamp 10 Spool 11 Sleeve 13 Coil spring

Claims (3)

[Claims] A storage means capable of accommodating a plurality of electrodes and sending out one by one, a feeding means for continuously feeding out the electrodes sent from the storage means at an arbitrary speed, and a feeding means for feeding out the fed out electrodes. An electrode feeding device, comprising: a rotation driving means for rotating; and a processing liquid supply means for supplying a processing liquid to a surface to be processed together with the electrode. 2. The feeding means has a clamp provided in series with respect to an electrode feeding direction of the storage means, and moves the clamp in a feeding direction of the electrode in a state where the electrode is tightened. 2. The electrode feeding device according to claim 1, further comprising a drive mechanism for displacing at an arbitrary speed, or displacing at a time in a direction opposite to the dispensing direction in a state where the tightening of the electrode is released. 3. The driving mechanism includes a cylindrical member that holds the clamp so that the clamp can be opened and closed, and a support member that rotatably supports the cylindrical member, wherein the cylindrical member and the support member include the support member. A first cam assembly that repeats a process of tightening the clamp while the rotation of the cylindrical member with respect to the predetermined angle and releasing the clamp when the rotation exceeds the predetermined angle; and a rotation of the cylindrical member with respect to the support member at a predetermined angle. During the rotation, the cylindrical member is moved in the feeding direction at a constant speed with respect to the supporting member with the rotation, and after the rotation of the predetermined angle, the cylindrical member is temporarily moved in the direction opposite to the feeding direction with respect to the supporting member. 3. The electrode feeding device according to claim 2, further comprising a second cam assembly that repeats a step of moving the electrode in the direction of.