Arc welding practice machine and rod handling practice paper support stand

Abstract

To provide an arc-welding practice machine by which a user can efficiently learn a manipulation in a covering arc-welding work.SOLUTION: An arc-welding practice machine 10 according to the present invention includes: a grip body 14; a movable member 28 like a stretchy rod rotatably attached to the grip body; direct-acting driving means 28, 36 for moving a top end part of the mobile member to a direction of the grip body from an initial position away from the grip body; control means for controlling the direct-acting driving means to adjust the mobile rate of the top end part of the mobile member; and a writing instrument attachment unit 40 provided to the top end part of the mobile body, a brush pen being equipped to the writing instrument attachment unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an arc welding trainer that allows a trainee to efficiently master the operation of a rod in shielded metal arc welding work. The present invention also relates to a training paper support stand for supporting a training paper for the operation of a rod in arc welding that is suitable for use with the arc welding trainer. [Background technology]

[0002] Shielded electrode arc welding is a type of consumable electrode arc welding method that uses a welding rod as the electrode, which is made of a core wire made of the same material as the base metal to be welded and a coating material that covers the core wire, and uses the arc formed between the core wire of this welding rod and the base metal as the heat source.

[0003] In shielded metal arc welding, the welding rod gradually becomes shorter as the welding progresses. Therefore, in order to finish the weld well, it is necessary to lower the welding rod according to the consumption of the welding rod and keep the distance between the tip of the welding rod and the base metal (corresponding to the arc length) constant. In addition, in order to stabilize the molten pool formed between the base metal and the core metal when the arc is generated, it is also necessary to move the welding rod at a constant speed relative to the surface of the base metal. Regarding the movement of the welding rod, there is a technique called weaving, in which the tip of the welding rod is moved left and right in the moving direction to form a wide bead, in addition to moving it in a straight line. In addition, it is also necessary to maintain a constant angle between the welding rod and the base metal. Thus, in order to perform good shielded metal arc welding, it is important to master how to move the welding rod, or what is called rod operation.

[0004] Rod handling practice is often carried out using an actual arc welding machine, a consumable welding rod, and a test piece made from processed steel, but since this is difficult to carry around and requires space to practice, there are time, financial, and space constraints on implementing this method.

[0005] For this reason, an arc welding training machine as described in the following Patent Document 1 has been proposed in the past. This conventional arc welding training machine includes a telescopic shaft and a writing implement such as a rod pen fixed to the tip of the telescopic shaft. When practicing, the user holds the telescopic shaft and moves the rod pen at the tip of the shaft to draw a path of the rod pen on a practice paper, thereby practicing rod operation. In particular, this arc welding training machine is capable of simulating the wear of a welding rod during a shielded metal arc welding operation by retracting the tip of the telescopic shaft. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 57-185478 Summary of the Invention [Problem to be solved by the invention]

[0007] The above-mentioned conventional arc welding training machine has a simple configuration, is small, and is portable. However, Patent Document 1 only describes a telescopic shaft configured by fitting elongated conical members together, and with this configuration, the telescopic shaft cannot maintain a straight rod shape when extended, and the tip of the telescopic shaft inevitably sags. Conversely, if the telescopic shaft is allowed to maintain a rod shape when extended, it is difficult to shorten it. Therefore, the arc welding training machine described in Patent Document 1 has an infeasible configuration. In addition, the arc welding training machine described in Patent Document 1 does not have a means for extending the telescopic shaft, which has been shortened, back to its original extended state, which is inconvenient.

[0008] Furthermore, Patent Document 1 describes only a rod pen as an example of a writing implement, but the lines drawn with this rod pen have a constant thickness. In other words, even if you look at the lines drawn with the arc welding training machine described in Patent Document 1, there is a problem in that you cannot judge whether the arc length, which is important in the operation of the rod in the shielded metal arc welding work, is constant.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a novel arc welding trainer which can solve the above-mentioned problems of the prior art. [Means for solving the problem]

[0010] In order to achieve the above object, an arc welding training machine according to a first aspect of the present invention is characterized in that it comprises a grip body that can be held by a user, a movable member rotatably attached to the grip body and whose tip is linearly movable from an initial position away from the grip body toward the grip body, a linear driving means for moving the tip of the movable member in the direction from the initial position toward the grip body, a control means for controlling the linear driving means to adjust the moving speed of the tip of the movable member, and a writing tool attachment section provided at the tip of the movable member to which a writing tool whose line thickness changes depending on writing pressure is attached. The writing tool is preferably a brush pen.

[0011] According to a second aspect of the present invention, there is provided a rod operation practice paper support stand suitable for use with the arc welding trainer, for supporting a practice paper for rod operation in shielded metal arc welding. The practice paper support stand includes a backing paper on which at least one line simulating the line drawn by the tip of the welding rod in shielded metal arc welding, i.e., the trajectory of the rod operation, is drawn as a tracing line, and a support stand main body having a mounting surface to which the backing paper is attached. The mounting surface of the support stand main body is configured so that light can be irradiated toward the backing paper attached to the mounting surface, and the backing paper is configured so that light from the mounting surface can be transmitted. When practicing rod operation, a practice paper for rod operation such as a Japanese writing paper is supported on the practice paper support stand so as to cover the backing paper. Effect of the Invention

[0012] The arc welding practice machine according to the first aspect of the present invention allows the practice of rod operation simply by tracing a practice paper for rod operation with a writing implement such as a brush pen attached to the writing implement attachment part at the tip of the movable member. In this case, various effects can be achieved, as will be described in detail in the "Description of the Preferred Embodiments" below, such as the writing implement being set to move away from the practice paper in the same way that the welding rod of an actual arc welding machine becomes shorter during operation, by control by the control means.

[0013] In addition, the stick handling practice paper support stand according to the second aspect of the present invention has a mount on which a tracing line imitating the trajectory of the stick is drawn, and a practice paper such as a piece of Japanese writing paper is placed on it, and the tracing line of the mount reflected on the practice paper can be traced with a writing implement to practice stick handling. In particular, by emitting light from the support stand body, it is possible to clearly project the tracing line of the mount on the practice paper, making stick handling practice even more efficient. [Brief description of the drawings]

[0014] [Figure 1] 1 is a side view showing a first embodiment of an arc welding training machine according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] 2 is a partially sectional side view showing the arc welding training machine of FIG. 1 in a folded shape. FIG. [Figure 4] FIG. 2 is a schematic explanatory diagram showing an example of a rod operation practice paper support stand for supporting a rod operation practice paper suitable for use with the arc welding training machine according to the present invention. [Diagram 5] FIG. 1 is a photographic diagram showing lines drawn using an arc welding practice machine and a rod operation practice paper support stand according to the present invention. [Figure 6] FIG. 11 is a schematic explanatory diagram showing a modified example of a support stand for an arc welding training paper suitable for use with an arc welding training machine according to the present invention. [Figure 7] FIG. 2 is a side view showing a second embodiment of an arc welding training machine according to the present invention. [Figure 8] FIG. 4 is a side view showing a third embodiment of an arc welding training machine according to the present invention. [Figure 9] FIG. 11 is a side view showing a fourth embodiment of an arc welding training machine according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention relates to a welding practice machine and a practice paper support for rod operation suitable for use with the machine, and is described in detail below with reference to the accompanying drawings. In addition, the same or corresponding parts are designated by the same reference numerals throughout the drawings, and duplicated explanations will be omitted.

[0016] 1 to 3 show a first embodiment of an arc welding trainer according to the present invention. In the illustrated embodiment, the arc welding trainer 10 is equipped with a grip body 14 having a grip portion 12 that is held by the user's hand. This grip body 14 preferably has the same dimensions as the electrode holder of an actual arc welder used in shielded metal arc welding work, and it is particularly effective for the grip portion 12 held by the hand to have the same shape and dimensions as the grip portion of the electrode holder. This is to allow training with a feel as similar as possible to that of the actual machine.

[0017] The end of the grip body 14 opposite to the grip portion 12 is bifurcated, and a writing implement holder 18 for holding a writing implement 16 is rotatably disposed between the two ends. A holder body 20 of the writing implement holder 18 is formed with a plurality of holes 22 (three in the illustrated embodiment) at positions equidistant from the center of rotation P. When the holder body 20 is folded relative to the grip body 14, these holes 22 are aligned with holes 24 provided in the grip body 14 at positions equidistant from the center of rotation P, and the holder body 20 can be fixed to the grip body 14 at a predetermined folding angle θ by screwing in a stopper pin 26 screwed into the hole 24 of the grip body 14. 1 and 2 (the angle indicated by θ in FIG. 3) is 0 degrees, the position indicated by the solid line in FIG. 3 is the bending angle θ of 90 degrees, and the intermediate position indicated by the two-dot chain line in FIG. 3 is the bending angle θ of 45 degrees. However, the bending angle θ is not particularly limited and may be continuously variable, and the fixing means for the holder body 20 does not need to be the stopper pin 26.

[0018] The writing implement holder 18 includes an extendable rod (movable member) 28 provided in the holder body 20. The extendable rod 28 has a nested structure like a rod antenna, and is a three-stage structure consisting of a first cylinder 32 slidably fitted into an elongated hole 30 formed in the holder body 20, and a second cylinder 34 slidably fitted into the first cylinder 32. The number of stages of the extendable rod 28 is not limited to three stages, and may be two stages or four or more stages.

[0019] The length of the extendable rod 28 is not particularly limited, but from the viewpoint of practicing an actual shielded metal arc welding operation, it is preferable that the length of the extendable rod 28 in its most extended state (see FIG. 3) is approximately equal to the length of an actual welding rod. On the other hand, the shortest state of the extendable rod 28 is shown in FIG. 1 and FIG. 2, and this length is preferably approximately equal to the length of an actual welding rod when it is completely used up.

[0020] In the illustrated embodiment, there is no play in the fitting relationship between the elongated hole 30 and the first cylindrical body 32, and in the fitting relationship between the first cylindrical body 32 and the second cylindrical body 34, and even when the telescopic rod 28 is extended to its maximum length, there is no bending that would cause it to warp from the telescopic direction.

[0021] The holder body 20 is formed with a portion extending in the direction opposite to the direction in which the telescopic rod 28 protrudes, and the motor 36 is attached to this portion. One end of the steel strip 38a of the coil spring 38 is fixed to the rotating shaft of the motor 36, and the other end of the steel strip 38a of the coil spring 38 passes through the elongated hole 30 of the holder body 20 and the inside of the first cylinder 32 and is connected to the end of the second cylinder 34. In the initial state of the coil spring 38 (a state in which no or almost no spring force is generated), as shown in FIG. 3, the connection end side of the steel strip 38a of the coil spring 38 tries to extend linearly. When the motor 36 is driven to wind the steel strip 38a of the coil spring 38 around the rotating shaft of the motor 36, the coil spring 38 pulls the second cylinder 34 and is accommodated in the first cylinder 32. When the motor 36 is further driven, the second cylinder 34 and the first cylinder 32 are housed together in the elongated hole 30 of the holder body 20, and reach the shortest position shown in FIG. 1. When the rotation of the rotating shaft of the motor 36 is reversed, the steel band 38a at the connection end of the coil spring 38 attempts to return to its original straight shape due to its elastic restoring force, and the straightened portion of the steel band 38a can transmit a pushing force along the longitudinal axis, so that the second cylinder 34 of the telescopic rod 28 is pushed, and the telescopic rod 28 can be returned to its initial position, which is the longest position. Alternatively, the telescopic rod 28 can be returned to its initial position by manually pulling the tip of the telescopic rod 28 while the driving force of the motor 36 is released.

[0022] It is considered that the rotation speed of the rotating shaft of the motor 36 is constant and the contraction speed of the telescopic rod 28 is constant. However, in actual shielded metal arc welding work, the speed at which the welding rod shortens varies depending on various factors such as the type of base material and the shape of the welded part. Therefore, it is necessary to adjust the speed of the rotating shaft of the motor 36 and, in turn, the contraction speed (movement speed of the tip) of the telescopic rod 28 by controlling the driving of the motor 36. As a control method, various methods are considered, such as a method of adjusting the amount of current supplied to the motor 36, a method of adjusting the voltage value, and a method of adjusting the waveform of the current applied if the motor 36 is a stepping motor. Although not shown, a control device (control means) and a power source, etc. that control the motor 36 may be built into the grip part 12, etc. of the arc welding training machine 10. However, since it is considered that the weight of the arc welding training machine 10 may greatly exceed the total weight of the welding rod holder and the arc welding rod of the actual arc welding machine, the control device and the power source, etc. may be provided separately from the arc welding training machine 10 in order to make the arc welding training machine 10 the same weight as the actual machine.

[0023] The writing instrument 16 is removably attached to the tip of the telescopic rod 28. More specifically, the tip of the telescopic rod 28 is provided with a writing instrument attachment part 40 consisting of a cylinder that receives the shaft of the writing instrument 16. The longitudinal axis of the cylinder of the writing instrument attachment part 40 is arranged substantially parallel to the telescopic direction of the telescopic rod 28. In addition, it is preferable that the inner peripheral surface of the cylinder of the writing instrument attachment part 40 is substantially similar in shape to the outer peripheral surface of the shaft of the writing instrument 16 and has a slight interference fit relationship so that the shaft of the writing instrument 16 can be easily inserted and removed and does not wobble after attachment. Alternatively, a configuration may be adopted in which a plurality of protrusions are formed on the inner peripheral surface of the cylinder of the writing instrument attachment part 40 to elastically hold the shaft of the writing instrument 16.

[0024] According to the present invention, the writing tool 16 is important because it is used to draw a line on a practice paper using the arc welding practice machine 10 and to see the result of the practice by observing the thickness and sway of the line. In particular, in an actual covered arc welding operation, the distance between the tip of the welding rod and the base metal, i.e., the arc length, must be kept constant, so that the thickness of the line drawn by the writing tool 16 must be constant in order to judge the result of the practice as good. On the other hand, if the writing tool 16 can only write with a constant thickness, it is not possible to judge the result of the practice, and it is not suitable for the arc welding practice machine 10 of the present invention. For this reason, it is necessary to select a writing tool 16 that changes the thickness of the line drawn even with a slight difference in writing pressure. As a writing tool 16 that meets such conditions, the present inventors conducted repeated experiments and diligent investigations, and found that the brush pen 16 is optimal.

[0025] The brush pen 16 is a conventionally known pen that consists of a shaft that holds ink liquid and a tip made of resin or animal hair that is attached to the end of the shaft and sucks up the ink liquid inside the shaft. In recent years, brush pens have become commercially available at low cost, so the financial burden is very small even if you practice many times on the arc welding training machine 10 and repeatedly replace the pen. Through experiments using various brush pens, the inventors of the present application found that the "Pentel Brush (Medium) (trademark)" made by Pentel Co., Ltd., which has a feel similar to that of shielded metal arc welding and can draw lines ranging from thin to relatively thick, is effective.

[0026] When practicing rod operation in a shielded arc welding operation using the arc welding training machine 10 described above, first, the telescopic rod 28 is extended to its maximum length and its tip is placed in the initial position farthest from the grip body 14. Then, the brush pen 16 is attached to the writing implement mounting portion 40 of the writing implement holder 18. The writing implement holder 18 is also bent to a desired bending angle θ with respect to the grip body 14 and fixed with the stopper pin 26. In an actual arc welding machine, the welding rod is often used at an angle of about 90 degrees with respect to the grip portion of the welding rod holder, so the bending angle θ is usually set to 90 degrees as shown in FIG. 3. After this, the user holds the grip portion 12 of the grip body 14 with his / her hand and adjusts the moving speed of the tip of the telescopic rod 28, i.e., the moving speed of the brush pen, by the control device. When the motor 36 is driven, the telescopic rod 28 contracts in the direction of the arrow A in FIG. 3, and the brush pen 16 attached to the tip of the telescopic rod 28 moves linearly toward the grip body 14 without warping from the telescopic rod 28's extension direction. The speed of this movement corresponds to the speed at which an actual welding rod wears out and shortens during a covered arc welding operation, so by gripping the grip part 12 of the grip body 14 and operating the brush pen 16 at the tip of the writing implement holder 18, it is possible to draw lines on a practice paper with the brush pen 16 with a feeling similar to that of operating an actual rod. The lines drawn on the practice paper become thinner if the brush pen 16 is too far away from the practice paper, and thicker if it is too close, so it is possible to determine in a simulated manner whether the arc length, which corresponds to the distance between the tip of the welding rod and the base metal, is constant. In addition, when the moving speed of the brush pen 16 changes, the writing pressure also changes, which also makes it possible to determine in a simulated manner whether the welding speed is appropriate, etc. Furthermore, if the angle of the brush pen 16 relative to the practice paper is unstable, the lines drawn on the practice paper will not be constant, which also makes it possible to determine whether the rod handling posture is correct. In this way, by using the arc welding trainer 10 of the present invention, the user can easily determine whether he or she has mastered rod handling correctly or whether he or she has improved, simply by looking at the lines drawn on the practice paper, without actually performing shielded metal arc welding work.

[0027] Once one stick-handling practice session is completed, the rotation of the motor 36 is reversed or the tip of the extendable rod 28 is pulled by hand to quickly return the brush pen 16 at the tip of the extendable rod 28 to its initial position, making it possible to practice repeatedly.

[0028] As described above, the arc welding training machine 10 according to the present invention has a relatively simple configuration, and therefore can be made small and lightweight, and has the advantage that training can be carried out anytime and anywhere without being restricted by time, money, or space.

[0029] By the way, actual shielded metal arc welding work includes not only butt welding of flat base materials, but also fillet welding and lap joint welding of base materials at right angles. In addition, there are various welding locations and shapes, such as welding of cylindrical pipes and welding of flanges. In order to practice such various shielded metal arc welding work and to further improve the level of proficiency, it is not enough to simply place the practice paper on a flat surface. In addition, the welding rod is not only moved in a straight line, but also in a zigzag movement, a movement while drawing a circle, a movement while drawing a figure eight, and other types of rod movements. In order to learn such a wide variety of rod movements, a method of tracing a traced line that imitates the rod movement is suitable.

[0030] In view of the fact that the arc welding training machine 10 of the present invention is suitable for using a brush pen 16 as a writing instrument, the inventors have devised a rod operation practice paper support stand for supporting rod operation practice paper, which is suitable for use with the arc welding training machine 10.

[0031] FIG. 4 shows an embodiment of the stick operation practice paper support stand 50 according to the present invention, in which thin paper with a see-through back, preferably Japanese writing paper, is used as the practice paper 52. Japanese writing paper is used because it is compatible with the brush pen 16 used in the arc welding practice machine 10. The shape of the stick operation practice paper support stand 50 can be various depending on the type of welding assumed in the practice, but for example, when practicing butt welding, a flat plate-like one as shown in FIG. 4 may be used. The stick operation practice paper support stand 50 shown in FIG. 4 is mainly composed of a flat support stand main body 54 and a mount 56 placed on its surface. The mount 56 has an ideal stick operation path drawn as a tracing line 58. There may be only one tracing line 58, but it is preferable to have multiple tracing lines in order to practice repeatedly, and as shown in FIG. 4, multiple types of tracing lines may be drawn in order to learn various stick operation methods. The mount 56 may be coated with a transparent resin or covered with a transparent film such as cellophane film to prevent the ink of the brush pen 16 from seeping through the writing paper 52 and soiling it. The mount 56 may be fixed to the support base body 54, but it is effective to dispose the mount 56 removably relative to the support base body 54 so that multiple types of mounts 56 can be used interchangeably. Furthermore, although not shown, it is preferable to provide a fixing means such as a pressing band to prevent the practice paper 52 from shifting when placed on the mount 56.

[0032] The tracing line 58 drawn on the mount 56 can usually be seen through a thin practice paper 52 such as a piece of Japanese writing paper placed on top of it, but in order to see the tracing line 58 more clearly, it is preferable to place a light source (not shown) on the back side of the support base body 54. The light source can be of various types, such as a flat backlight used in liquid crystal displays and the like, or a rod-shaped backlight having a reflector. The light source may be one mounted on the support base body 54, or may be a normal desk lamp that can be installed behind the support base body 54 instead of a special light source. In any case, when a light source is used, it is necessary for light to be irradiated from the mounting surface 60 of the support base body 54 to which the mount 56 is attached. It is also preferable that the mount 56 has a certain degree of translucency.

[0033] FIG. 5 shows a case where a practice paper 52 is placed on the rod operation practice paper support stand 50 so as to cover the backing paper 56, and a weaving trace line 58 is traced with a brush pen 16 using the arc welding practice machine 10 according to the present invention. The line on the left side of FIG. 5 was drawn by a person with a certain level of skill, and it can be seen that the line width, vertical spacing, and line thickness are uniform. On the other hand, the line on the right side was drawn by a beginner in shielded metal arc welding, and it can be seen that the line width, vertical spacing, and line thickness are uneven in places. The uneven line thickness indicates that the angle and arc length of the telescopic rod 28, which imitates a welding rod, are not stable with respect to the surface of the practice paper 52, which imitates the welding point of the base material, and the uneven line width and vertical spacing indicate that the rod operation is not performed smoothly. In particular, if we look at the enlarged view in Figure 4, which shows a portion of the line on the right side, we can see that there are a series of alternating thick and thin line sections at short intervals. This means that the tip of the brush pen 16 is moving up and down in relation to the surface of the practice paper 52, which is evidence that the arc length may become unstable.

[0034] As can be understood from the above, it is easy for the user to judge for himself or herself whether the line drawn using the arc welding training machine 10 of the present invention deviates from the tracing line, whether the width and thickness of the line are constant, and whether the spacing between the top and bottom is constant.

[0035] Incidentally, the shape of the stick handling practice paper support stand 50 is not limited to that shown in FIG. 4. For example, the stick handling practice paper support stand 50 shown in FIG. 6 is designed for welding to steel pipes, and the support stand body 54 is cylindrical. In the case of circumferential welding in this support stand 50, the backing paper 56 is arranged so that its tracing line 58 faces the circumferential direction of the support stand body 54, and in the case of vertical upward welding, although not shown, the backing paper 56 is arranged so that its tracing line 58 is parallel to the longitudinal axis of the support stand body 54. In addition, various other shapes of the support stand body 54 of the stick handling practice paper support stand 50 are possible, and by preparing many different types, it is possible to acquire various stick handling skills and it will also be useful for practice before performing welding work on site.

[0036] The rod handling practice paper support stand 50 according to the present invention was devised in conjunction with the creation of the arc welding training machine 10 according to the present invention, and although it is possible to use it separately from the arc welding training machine 10, it is more preferable to use it in combination with the arc welding training machine 10 in order to improve rod handling skills.

[0037] Although the preferred embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above embodiment and various modifications can be made.

[0038] For example, FIG. 7 shows an arc welding training machine 10' according to a second embodiment of the present invention, which differs from the arc welding training machine 10 according to the first embodiment shown in FIGS. 1 to 3 in that the telescopic rod 28 is arranged in seven stages. The arc welding training machine 10' also differs from the arc welding training machine 10 of the first embodiment in that the center of gravity of the motor 36 is located away from the grip part 12 of the grip body 14. Due to this arrangement of the motor 36, when the telescopic rod 28 is bent around the rotation center P, the center of gravity of the motor 36 is located close to the longitudinal axis of the grip part 12. In particular, when the bending angle θ is set to 90 degrees, the center of gravity of the motor 36 is substantially located on the longitudinal axis of the grip part 12, and a large moment force is not generated in the hand holding the grip part 12, allowing stable arc welding practice.

[0039] FIG. 8 shows an arc welding training machine 10″ according to a third embodiment of the present invention. This arc welding training machine 10″ has a similar configuration to the arc welding training machine 10′ according to the second embodiment shown in FIG. 7, but the two differ in the configuration of the writing part attachment part. The arc welding training machine 10″ according to the third embodiment was devised in consideration of the fact that some commercially available brush pens have a tip and an ink cartridge that are integrated and can be removed from the shaft and replaced. That is, in this third embodiment, the cylindrical body 60 at the tip of the telescopic rod 28 itself serves as the writing implement attachment part, and the tip and ink cartridge integrated part 16′ is configured to be removably fitted inside the cylindrical body 60. With this configuration, the tip of the brush pen 16′ and the telescopic rod 28 are coaxial, making it possible to practice arc welding with a feeling that is even more similar to that of an actual welding rod. The tip and ink cartridge integrated part 16′ can be that of a commercially available brush pen, but it is of course possible to prepare one specifically for the arc welding training machine according to the present invention.

[0040] FIG. 9 shows an arc welding training machine 10'" according to a fourth embodiment, in which the brush pen 16 can be attached to the cylindrical body 60 at the tip of the extendable rod 28 with the shaft still attached. This arc welding training machine 10'" differs from the arc welding training machines shown in FIGS. 7 and 8 in that the extendable rod 28 has four stages. This configuration differs from those shown in FIGS. 1 to 3, 7 and 8 in that the end of the writing implement holder 18 extends to the middle position of the grip part of the grip body 14 in order to sufficiently draw the cylindrical body 60 at the tip toward the grip body 14.

[0041] It should be noted that in the arc welding training machine 10", 10'" of the embodiment in Figures 8 and 9, the longitudinal axis of the telescopic rod 28 and the brush pen 16, 16' passes through the center of rotation P of the connection with the grip body 14. In this arrangement, the position, dimensions and angle at which the brush pen 16, 16' is attached to the tip of the writing implement holder 18 are the same as or very close to those when a welding rod is attached to the welding rod holder of an actual arc welding machine, which also makes it possible to practice arc welding with a feeling close to that of actual arc welding.

[0042] Other various modifications are possible. For example, in the above embodiment, the telescopic rod has a nested structure and is linearly moved by a coil spring, but any movable member or linear driving means that can move the tip portion holding the writing tool linearly without bending may be used, and various mechanisms such as a rack and pinion mechanism, a ball screw mechanism, and a linear actuator are conceivable. The means for returning the writing tool to the initial position does not need to utilize the reverse rotation of the motor and the elastic restoring force of the spring, and a compression spring may be disposed in the telescopic rod. In addition, a coil spring is used to contract the telescopic rod, but a member such as a wire or strip that does not have elasticity may also be used. Furthermore, the writing tool attachment may be a clip or the like. Furthermore, the present invention is applicable to any writing tool that changes the thickness of the line depending on a slight difference in writing pressure, so the writing tool is not limited to a brush pen. [Explanation of symbols]

[0043] 10,10',10",10'"...arc welding practice machine, 14...grip main body, 16,16'...writing implement (brush pen), 18...writing implement holder, 20...holder main body, 28...telescopic rod (movable member, linear driving means), 36...motor (linear driving means), 38...coil spring, 40...writing implement attachment portion, 50...rod operation practice paper support base, 52...practice paper (half-sized paper), 54...support base main body, 56...backing paper, 58...tracing line, 60...mounting surface.

Claims

[Claim 1] A grip body that can be held by a user with a hand; a movable member rotatably attached to the grip body, the movable member having a tip portion linearly movable from an initial position away from the grip body in a direction toward the grip body; a linear motion drive means for moving the tip end of the movable member from the initial position in a direction toward the grip body; A control means for controlling the linear motion drive means to adjust the moving speed of the tip of the movable member; a writing tool attachment portion provided at the tip of the movable member, to which a writing tool whose line thickness changes according to writing pressure is attached; Equipped with The arc welding training machine, wherein the writing implement is a brush pen.

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