JP5388116B2 - Plasma torch - Google Patents

Description

  The present invention relates to a plasma torch for attaching and detaching an insert tip.

  The insert tip of the plasma torch having a nozzle for ejecting plasma is consumed due to the high heat of the plasma and is damaged by the splash (sputtering) of the molten metal of the workpiece, and therefore needs to be replaced. That is, the insert tip is a consumable item.

  In Patent Document 1, in order to extend the life of the insert tip, a taper male screw with a small tip diameter is cut into the insert tip and screwed into a taper female screw with a large tip diameter at the tip of a water channel fitting as a nozzle base. A plasma torch with improved heat conduction and improved cooling performance of the insert tip by the water channel fitting is presented.

Japanese Patent Application Laid-Open No. 2008-212969.

  The insert tip of the plasma torch having a nozzle for ejecting plasma is consumed due to the high heat of the plasma and is damaged by the splash (sputtering) of the molten metal of the workpiece, and therefore needs to be replaced. That is, the insert tip is a consumable item.

  In Patent Document 1, in order to extend the life of the insert tip, a taper male screw with a small tip diameter is cut into the insert tip and screwed into a taper female screw with a large tip diameter at the tip of a water channel fitting as a nozzle base. A plasma torch with improved heat conduction and improved cooling performance of the insert tip by the water channel fitting is presented.

  However, when replacing the worn insert tip, when the insert tip is tightened or loosened, if the tip of the channel fitting is not firmly fixed (restrained) at the tip of the torch, the channel fitting will move around with the insert tip. Since it is idle (spinning), the work of fixing and holding the water channel fitting at its tip is complicated. If the water channel fitting is insufficiently fixed and easily slips, if the screw tightening is loosened in order to avoid idling, the heat conduction from the insert tip to the water channel fitting is poor, and the wear of the insert tip is extremely short. In particular, the cooling water inlet and outlet of the waterway fitting are at the same position in the longitudinal direction of the waterway fitting, at both ends of the same diameter, and the water supply pipe and drainage pipe ports are on the torch body side, and the cooling water inlet and outlet of the waterway fitting are When the water channel fittings are rotated in the torch body so that they are opposed to each other, the cooling water inlet and outlet of the water channel fitting are not connected to the water supply pipe on the torch body side and the drain pipe port. It will shift | deviate to a direction, the water flow of the cooling water in a water channel metal fitting will become thin, and insert chip cooling capacity will fall. In this case, the insert tip life is shortened.

  An object of the present invention is to make it easy to attach and detach an insert tip to and from a waterway fitting and to enhance the reliability and stability of heat removal from the insert tip.

(1) An insert tip (5) having a nozzle (51) for injecting plasma at the center of the tip and having an external thread (53) at the rear end cylinder part, and an inner hole (61) at the center and cooling water on the outside A water channel fitting (6) having a flow path and having a female screw hole (68) into which the male screw (53) of the insert tip (5) is screwed at the tip of the inner hole (61), and the inner hole (61 ) And the tip of the electrode rod (8) facing the nozzle (51), and the centering that is in the insert tip (5) and supports the electrode rod (8) at the center axis position of the nozzle (51) A stone (9), a torch body (1) having a storage space for receiving the water channel fitting (6) from its rear end side, and a constraint for preventing rotation of the water channel fitting (6) in the torch body (1). comprising a stop means (65,11 / 66,12), a
The cooling water flow path of the water channel fitting (6) includes a water supply channel (63) for sending cooling water from the rear end portion of the water channel fitting (6) to a front end portion and a drainage channel returning from the front end portion to the rear end portion ( 64), and the detention means is in a detained state in which rotation of the water channel fitting (6) is prevented, the water supply channel (63) is a water supply pipe (14a), and the drainage channel (64) is a drainage pipe. , Each connected,
Plasma torch.

  In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the equivalent element of the Example which is shown in drawing and mentions later in parentheses is attached for reference by reference. The same applies to the following.

  When replacing the worn insert tip, insert the insert tip (5) by holding the torch body (1) and applying the male screw (53) of the insert tip (5) to the female screw hole (68) of the channel fitting (6). Since the water channel fitting (6) does not slip even if it is screwed in and turned strongly, the insert tip (5) can be easily attached and detached by turning driving with a relatively strong force. There is no need to fix and hold the water channel fitting at its tip. In addition, the cooling water inlet and outlet of the waterway fitting are at the same position in the longitudinal direction of the waterway fitting and at both ends of the same diameter, and the water supply pipe and drainage pipe ports on the side of the torch body, the cooling water inlet and outlet of the waterway fitting When they are in opposite fixed positions so that they face each other, rotation of the water channel fittings is prevented by the restraining means, so that the cooling water inlet and outlet of the water channel fittings are connected to the water supply pipe and drain pipe port on the torch body side. Therefore, the insert tip cooling capacity is not lowered.

In addition, in the case of a cooling channel setting where the water channel fitting (6) must be positioned at a specific angle to align the water supply channel of the water channel fitting (6) with the water supply pipe and the drainage channel with the drainage pipe, By setting the rotation angle of the water channel fitting (6) to the detention state in which the means prevents rotation of the water channel metal fitting (6), the cooling water channel setting is automatically realized by the holding means. Can do.

It is a front view which fractures | ruptures and shows a part of plasma torch of 1st Example of this invention. (A) is an enlarged plan view of the waterway fitting 6 shown in FIG. 1, (b) is a right side view, and (c) is a cross-sectional view taken along line 2c-2c of (a) of FIG. (A) is an enlarged vertical sectional view of a threaded portion between the female screw 68 of the water channel fitting 6 and the male screw 53 of the insert tip 5 shown in FIG. 1, and (b) shows the lower limit angle of the male screw 53 of the insert tip 5, (C) shows the upper limit angle. It is a front view which fractures | ruptures and shows a part of plasma torch of 2nd Example of this invention. (A) is an enlarged plan view of the waterway fitting 6 shown in FIG. 4, (b) is a right side view, and (c) is a cross-sectional view taken along line 2c-2c of (a).

  (2) The water channel fitting (6) has an inner taper surface (67) at the tip opening of the female screw hole (68), and the insert tip (5) is an outer taper surface (abutting the inner taper surface (67)). 52) The plasma torch according to (1) above. Since the contact of the taper surface has high adhesion and a large contact area, the cooling effect of the insert chip is high.

( 3 ) The water channel fitting (6) includes a water supply port (13a) communicating with the water supply space (63) therein and a water discharge port (13b) communicating with the drainage space (64) of the water channel fitting (6). A ring-shaped water supply passage in which the water supply port (13a) opens, and a ring in which the water discharge port (13b) opens, in positions corresponding to these positions inside the torch body (1), which are shifted in the axial direction (1) or (2), wherein a water supply pipe (14a) communicates with the water supply passage, and a water discharge pipe (14b) communicates with the water supply passage. Plasma torch. In this aspect, even if the water channel fitting (6) rotates in the torch body (1), the cooling water flow path of the water channel fitting (6) does not narrow, so that the restraining means (65, 11/66, 12) However, when replacing the worn insert tip, hold the torch body (1) and insert the male screw (53) of the insert tip (5) into the female screw hole (68) of the channel fitting (6). Even if the insert tip (5) is screwed in and turned strongly, the waterway fitting (6) is prevented from idling, so that the insert tip (5) can be easily attached and detached by turning driving with a relatively strong force. There is no need to fix and hold the water channel fitting at its tip.

( 4 ) The female thread (68) of the channel fitting (6) has a cross section perpendicular to the screw shaft on the bottom side and is 10 degrees or more and 30 degrees or less on the front side and 20 degrees or more and 35 degrees or less on the back side. In addition, the plasma torch according to any one of (1) to (4), wherein the thread is inclined at 20 to 45 degrees with respect to a surface parallel to the screw axis on the summit side. .

The male screw (53) of the insert tip (5) that is properly aligned with and screwed to the female screw (68) is 10 degrees or more and 30 degrees or less on the front side, which is the nozzle side of the cross section perpendicular to the screw shaft on the mountain top side. In addition, the thread is inclined at 20 to 35 degrees on the back side, and is inclined at 20 to 45 degrees with respect to the plane parallel to the screw axis on the valley bottom side. In this way, the top of the thread of the female screw hole (68) of the water channel fitting (6) is from the top of the male thread (53) of the insert tip (5) as shown in FIGS. However, since it is thick and gently inclined, wear due to the insertion and removal of the insert tip (5) is small, and the water channel fitting (6) has a long life. Accordingly, the male thread (53) of the insert chip (5) is easily deformed by attaching and detaching the insert chip (5) to and from the waterway fitting (6). ) In close contact with the female screw hole (68) of the water channel fitting (6). Since the insert tip (5) is a consumable item, deformation and wear of the thread when it is removed from the channel fitting (6) does not matter.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

-1st Example-
FIG. 1 shows the plasma torch of the first embodiment. In the plasma torch of the first embodiment, an insert tip 5 that is a tip member and a nozzle member can be attached to and detached from a water channel fitting 6 that is a nozzle base. Further, the water channel fitting 6 can be detached from the torch body 1.

  There is a centering stone 9 in the inner hole of the insert tip 5, and the tip of the electrode rod 8 penetrating the centering stone 9 enters the insert tip 5 and faces the nozzle 51. The pilot gas enters the insert tip 5 through the vent hole of the centering stone 9 from the supply pipe (not shown) through the pilot gas path 10 of the inner hole 61 of the torch body 1 and the water channel fitting 6, It is ionized by the arc generated at the tip to become plasma gas and is ejected from the nozzle 51.

  The male screw 53 at the rear end of the insert tip 5 is screwed into the female screw hole 68 of the water channel fitting 6, whereby the outer taper 52 of the insert tip 5 is pressed against the inner taper 67 at the tip of the water channel fitting 6. The shield gas blown from the shield gas pipe 15 to the outer peripheral surface of the water channel fitting 6 exits the inner space of the shield cap 2 through the through-hole at the tip of the cap nut 7, and goes outside the torch along the outer peripheral surface of the insert tip 5. To leak.

  In FIG. 2, the water channel | path metal fitting 6 is expanded and shown. The water channel fitting 6 is roughly a double cylinder, and there is a water channel 4 between the inner cylinder 62 and the outer cylinder. When the water channel 4 is expressed by the inner cylinder 62 and the x direction is expressed as the vertical direction, the water channel 4 is divided into upper and lower parts. ((C) of FIG. 2). The upper side is a water supply space 63 and communicates with the cooling water supply pipe 14a. A lower side is a drainage space 64 and communicates with the drainage pipe 14b. On the rear end surface of the water channel fitting 6 (the right end surface on FIG. 2A) are engaging grooves 65 and 66 for receiving the locking pins 11 and 12 shown in FIG. And is fixed to the torch body 1. In this embodiment, the restraining means is constituted by the locking pins 11 and 12 and the engaging grooves 65 and 66.

  A groove similar to the engagement grooves 65 and 66 of the water channel fitting 6 that receives the pins 11 and 12 is provided on the end surface of the water channel metal receiving base 16 that is integrally fixed to the torch body 1 and that faces the rear end surface of the water channel fitting 6. The holes 162 and 164 are engraved, and the protrusions 161 and 163 are formed by press-fitting the pins 11 and 12. The locking pins 11 and 12 are also fixedly supported by these grooves and holes 162 and 164, and the strength of the locking pins 11 and 12 to prevent the water channel fitting 6 from rotating is high.

  As shown in FIG. 1, the water supply pipe 14 a communicates with the water supply space 63 and the drain pipe 14 b communicates with the drain space 64, with the locking pins 11 and 12 fitted in the engagement grooves 65 and 66. A cooling water flow path is formed.

  When the insert tip 5 is turned counterclockwise strongly in the detained state, that is, in the state where the locking pins 11 and 12 are fitted in the engagement grooves 65 and 66 as shown in FIG. 5 can be removed. In addition, a new insert tip can be strongly screwed into the water channel fitting 6. In these cases, since the rotation of the water channel fitting 6 is prevented by the pins 11 and 12, the water channel fitting 6 does not run idle, and the insert tip 5 can be easily attached and detached by a powerful screwdriver.

  FIG. 3A is an enlarged view of a threaded portion of the male screw 53 of the insert tip 5 with respect to the female screw 68 of the water channel fitting 6 shown in FIG. In this embodiment, in order to increase the durability of the female thread 68 of the water channel fitting 6 with respect to the insertion and removal of the insert tip 5 and to extend the life of the water channel fitting 6, the thread of the female screw hole 68 of the water channel fitting 6 is It is inclined at 15 ° on the front side of the cross section perpendicular to the screw shaft on the side and 33 ° on the back side, and at 32 ° with respect to the surface parallel to the screw shaft on the peak side. Thereby, as shown to (a) of FIG. 3, the crest part of the female thread hole 68 of the water channel metal fitting 6 which is a non-consumable product is a solid thing with a thick crest and roundness. Since the contact angle of the male screw thread 53 with respect to the female screw thread 68 is as small as 15 degrees, the force for expanding the valley of the female screw 68 when the insert tip 5 is fastened to the water channel fitting 6 is reduced. Less deformation and wear. Note that the arrow direction of the z arrow in FIG. 3 is the screwing direction of the male screw 53 into the female screw hole 68.

As a result, the thread of the male thread 53 of the insert tip 5 screwed into the female thread hole 68 is inclined at 15 degrees on the front side, which is the nozzle side of the cross section perpendicular to the screw axis on the peak side, and 33 degrees on the back side. Moreover, it is inclined at 32 degrees with respect to the plane parallel to the screw axis on the bottom side. Thereby, as shown to (a) of FIG. 3, the crest part of the screw thread of the external thread 53 of the insert chip | tip 5 becomes a thing with a thin crest and easy to deform | transform.

  Since the thread of the female screw 68 of the water channel fitting 6 is thicker and more gently inclined than the male screw 53 of the insert tip 5, deformation and wear due to screwing and loosening when the insert tip 5 is attached and detached are small. Long life. Accordingly, the male screw 53 of the insert tip 5 is easily deformed by attaching and detaching the insert tip 5 to and from the water channel fitting 6, but the deformation at the time of mounting makes the male screw 53 of the insert tip 5 closely contact the female screw hole 68 of the water channel fitting 6. There are advantages. Since the insert tip 5 is a consumable item, deformation and wear of the thread when it is removed from the water channel fitting 6 do not become a problem.

  As shown in FIG. 3B, the female screw 68 is inclined at 10 degrees on the front side of the cross section perpendicular to the screw axis on the bottom side and 20 degrees on the back side, and parallel to the screw axis on the peak side. If the angle is 20 degrees with respect to the surface, the contact angle of the male thread 53 with respect to the female thread 68 is as small as 10 degrees, so that the valley of the female thread 68 when the insert tip 5 is fastened to the water channel fitting 6 is widened. The force to try is small, and the deformation and consumption of the female screw 68 are small. However, the male screw 53 to be screwed into this is inclined at 10 degrees on the front side of the cross section perpendicular to the screw axis on the summit side and 20 degrees on the back side, and on the bottom side with respect to the plane parallel to the screw axis. It is 20 degrees and is extremely thin and easily damaged, which is a practical limit (lower limit).

  As shown in FIG. 3 (c), the female screw 68 is inclined at 30 degrees on the front side of the cross section perpendicular to the screw axis on the bottom side and 35 degrees on the back side, and parallel to the screw axis on the peak side. If the angle is 45 degrees with respect to the surface, the effect that the durability of the female screw 68 is higher than that of the conventional one can be obtained. Since the angle of the male screw thread 53 with respect to the female screw thread 68 is slightly small at 30 degrees, there is little force to widen the valley of the female screw 68 when the insert tip 5 is fastened to the water channel fitting 6, and the deformation and consumption of the female screw 68 are reduced. Less is. The male screw 53 is inclined at 30 degrees on the front side of the cross section perpendicular to the screw axis on the peak side and 35 degrees on the back side, and at 45 degrees with respect to the plane parallel to the screw axis on the bottom side. It is thick and difficult to break. This is the limit (upper limit) at which a practical effect can be obtained.

  Therefore, the male screw 53 of the insert tip 5 is inclined at 10 ° to 30 ° on the front side of the cross section perpendicular to the screw shaft on the mountain top side, and at 20 ° to 35 ° on the back side, and the screw shaft on the valley bottom side. The female thread 68 of the water channel fitting 6 is at least 10 degrees and not more than 30 degrees on the front side of the cross section perpendicular to the screw axis on the bottom side and on the back side. Therefore, it is practically preferable that the screw thread is inclined at 20 degrees or more and 35 degrees or less, and is inclined at 20 degrees or more and 45 degrees or less with respect to the surface parallel to the screw axis on the peak top side. In this way, the top of the thread of the female screw hole (68) of the water channel fitting (6) is thicker than the top of the male thread 53 of the insert tip 5 as shown in FIGS. Because of the gentle inclination, deformation and wear due to the attachment / detachment of the insert tip 5 are small, and the water channel fitting 6 has a long life. Accordingly, the male screw 53 of the insert tip 5 is likely to be deformed by attaching and detaching the insert tip 5 to and from the water channel fitting 6. There is an advantage of improving the heat transfer efficiency from the male screw side which is the heat generation side to the female screw which is the heat absorption side. Since the insert tip 5 is a consumable item, deformation and wear of the screw thread when it is removed from the water channel fitting 6 does not matter.

-Second Example-
FIG. 4 shows the plasma torch of the second embodiment. In the plasma torch of the second embodiment, the insert tip 5 that is a tip member and a nozzle member can be attached to and detached from the water channel fitting 6 that is a nozzle base. The water channel fitting 6 of the second embodiment can be detached from the torch body 1 as shown in FIG. In the water channel fitting 6 used in the second embodiment, the water supply port 13a that communicates with the water supply space 63 and the water discharge port 13b that communicates with the drainage space 64 are in a position shifted in the vertical direction z (the axial direction of the water channel fitting 6). A ring-shaped water supply passage in which the water supply port 13a opens and a ring-shaped water discharge passage in which the water discharge port 13b opens are located at positions corresponding to these positions in the torch body 1, and the water supply pipe 14a is provided in the water supply passage. The drainage pipe 14b communicates with the drainage passage. Since each of the water supply passage and the drainage passage has a ring shape, the water supply space 63 of the waterway fitting 6 communicates with the water supply pipe 14a and the water discharge space 64 communicates with the drainage pipe 14b regardless of the rotation angle of the water supply fitting 6. In other words, it is not necessary to set the water channel fitting 6 at a specific rotation angle with respect to the torch body 1 in order to form the cooling water flow channel.

  However, in order to prevent idling of the channel fitting 6 with respect to the torch body 1 when the insert tip 5 is screwed or loosened when the insert tip 5 is attached to or detached from the channel fitting 6, the channel fitting 6 is the same as in the first embodiment. The rear end surface (the right end surface on FIG. 5A) has engaging grooves 65 and 66 for receiving the locking pins 11 and 12 shown in FIG. 1, and the pins 11 and 12 are the inner space of the torch body 1. And is fixed to the torch body 1. Also in this embodiment, the restraining means is constituted by the locking pins 11 and 12 and the engaging grooves 65 and 66. Thereby, even if the torch body 1 is grasped and the male screw 53 of the insert tip 5 is applied to the female screw hole 68 of the water channel fitting 6 and the insert tip 5 is screwed and rotated strongly, the water channel metal fitting 6 does not rotate freely. It is easy to attach and detach by turning driving with a relatively strong force. Other configurations of the second embodiment are the same as those of the first embodiment.

1: Torch body
2: Shield cap 3: Shield packing 4: Water channel 5: Insert tip 51: Nozzle 52: Outer taper portion 53: Male screw 6: Water channel fitting 61: Inner hole 62: Inner cylinder 63: Water supply space 64: Drainage spaces 65, 66: Locking groove 67: Tip receiving end 68: Female screw 7: Shield gas ejection part 8: Electrode rod 9: Centering stone 10: Pilot gas path 11, 12: Positioning pin 13: Cooling water channel systems 14a, 14b: Cooling water pipe 15: Shield gas pipe 16: waterway fitting cradle 161, 163: protrusion 162, 164: groove 17: insulation bush

Claims (4)

An insert tip having a nozzle for injecting plasma at the center of the tip and having an external thread at the rear end cylindrical portion, and an inner hole at the center and a cooling water passage on the outside thereof, the insert tip at the tip of the inner hole A water channel fitting having a female screw hole into which the male screw is screwed, an electrode rod that enters the inner hole and has a tip facing the nozzle, and the electrode rod is located in the center of the insert tip. A centering stone that supports the position, a torch body having a storage space for receiving the water channel fitting from its rear end side, and a restraining means for preventing rotation of the water channel metal fitting in the torch body ,
The cooling water passage of the water channel fitting includes a water supply channel for sending cooling water from the rear end of the water channel fitting to the front end and a drainage channel for returning from the front end to the rear end, and the restraining means includes the water channel. In the detention state that prevents the rotation of the metal fitting, the water supply channel is connected to the water supply pipe, and the drainage channel is connected to the drainage pipe,
Plasma torch.   2. The plasma torch according to claim 1, wherein the water channel fitting has an inner tapered surface at a front end opening of the female screw hole, and the insert tip has an outer tapered surface abutting against the inner tapered surface.   The water channel fitting has a water supply port communicating with the water supply space therein and a water discharge port communicating with the drainage space at positions shifted in the axial direction of the water channel fitting, and positions corresponding to these positions inside the torch body. A ring-shaped water supply passage that opens the water supply port, and a ring-shaped water supply passage that opens the water discharge port, and a water supply pipe communicates with the water supply passage, and a drain pipe communicates with the water supply passage The plasma torch according to claim 1 or 2, wherein The female thread of the waterway fitting is inclined at 10 ° to 30 ° on the front side which is the nozzle side of the cross section perpendicular to the screw axis on the valley bottom side, and at 20 ° to 35 ° on the back side, and on the summit side. The plasma torch according to any one of claims 1 to 4, wherein the plasma torch is a thread inclined at an angle of 20 degrees or more and 45 degrees or less with respect to a plane parallel to the screw axis.

Images