JPH08118028A - Welding torch and build up welding equipment - Google Patents

Abstract

PURPOSE: To provide a welding torch capable of evenly executing build up welding by welding to the prescribed position by uniformly jetting welding material from plural material jetting holes of nozzle tip. CONSTITUTION: Material passages 6a, 6b are formed to a welding torch main body 5, plural material jetting holes 14a-14d are formed to a nozzle tip 16. A tip holding nut 12 accommodates and locks a nozzle tip 16 and is screwed to a male screw 15 formed on the outer tapered face of welding torch main body 16 so as to support the nozzle tip 16 to the welding torch main body 5. The protrusion to regulate the peripheral position of nozzle tip 16 is arranged integrally to an annular projecting part 18 of nozzle tip 16, by the fit between the protrusion and the recessed part arranged to welding main body 5, the nozzle tip 16 is peripherally positioned so that the material passages 6a, 6b of welding torch main body 5 are located between adjacent holes of each hole 14a, 14b, 14c, 14d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding torch for overlay welding of dissimilar materials onto a valve head of an intake valve or an exhaust valve of an internal combustion engine, and a overlay welding apparatus equipped with the welding torch.

[0002]

2. Description of the Related Art FIG. 6 is a longitudinal sectional view of a conventional welding torch of this type, and FIGS. 7A and 7B are sectional views taken along arrows AA and BB of FIG. 6, respectively. Is. As is well known, for example, a valve head of an intake valve or an exhaust valve of an internal combustion engine is required to have high wear resistance. Therefore, as shown in FIG. 6, a material having high wear resistance (for example, Co—Cr—WC alloy) is welded to the valve head 2 of the valve 1 (see reference numeral 3 in the drawing). There is.

As shown in FIGS. 6 and 7, a conventional welding torch 80 for overlay welding a valve head has a plasma gas passage 84 (hereinafter referred to as a gas passage) inside.
The inner cylinder (torch body) 81 and the outer cylinder 82 provided on the outer side of the inner cylinder 81 and having the shield cap 95 at the tip are provided. The inner cylinder 81 has a plurality of (two in this example) passages 87a, 87b for introducing a powdery welding material.
(Hereinafter, referred to as a material passage), and an electrode (made of, for example, tungsten) 83 is provided in the gas passage 84 of the inner cylinder 81. The tip of the gas passage 84 is configured to open to the tip side in a state of being joined with the material passages 87a and 87b.

A gas such as argon gas is supplied to the gas passage 84 from a plasma gas supply device (not shown), and a powder supply means (not shown) is supplied to the material passages 87a and 87b. The powdery welding material is supplied while being contained in a carrier gas (carrier gas) from a carrier gas supply device (not shown). Further, a shield gas passage 97 is formed between the shield cap 95 at the tip of the outer cylinder 82 and the inner cylinder 81, and an argon gas is supplied to the shield gas passage 97 by a shield gas supply device (not shown). Shield gas such as gas is supplied.

Nozzle tips 92 are fixed to the tip of the inner cylinder 81 by direct screw connection, and a plurality of nozzle tips (four in this example) are inclined with respect to the axis of the nozzle tips 92.
Material ejection holes 96a, 96b, 96c, 96d are formed. An annular groove 86 is formed in the nozzle tip 92, and the welding material flowing out from the material passages 87a and 87b once enters the groove 86 and then the material injection hole 9 is formed.
It is configured to be ejected through 6a, 96b, 96c, 96d. A predetermined transferred arc voltage is supplied between the electrode 83 and the bulb 1, and a pilot arc voltage is applied between the electrode 83 and the nozzle tip 92.

In this welding torch 80, the electrode 83
A predetermined current is supplied between the electrode 1 and the valve 1 to generate a plasma arc between the electrode 83 and the valve 1, and a predetermined amount is supplied from a powder supply means (not shown) and a carrier gas supply device (not shown). The carrier gas containing the welding material is passed through the material passage 87.
a, 87b, and is ejected from the material ejection holes 96a, 96b, 96c, 96d of the nozzle tip 92. Then, the jetted powder material is melted by the plasma arc and is welded to the valve head 2 of the valve 1 by overlay welding (see reference numeral 3). At this time, the shield gas is ejected from the shield gas passage 97 around the plasma arc ejected from the passage of the nozzle.

[0007]

By the way, in the above-mentioned conventional welding torch, since the nozzle tip is fixed to the inner cylinder (welding torch body) by direct screw connection, the welding torch body of the nozzle tip may be used depending on the welding torch. The position in the circumferential direction with respect to will vary relatively. As a result, as shown in FIGS. 6 and 7, for example, when the material ejection holes 96a and 96c are located directly below the material supply passages 87a and 87b, the welding material flowing out from the material supply passages 87a and 87b is below. Concentrated inflow into the material ejection holes 96a and 96c, whereby the material ejection holes 96a and 96b,
The welding material is ejected nonuniformly from 96c and 96d. As a result, there is a problem that the build-ups 3a and 3b are unevenly distributed as shown in FIG. 8A or 8B, and the quality of the product deteriorates. Further, in the overlay welding apparatus using this welding torch, there is a problem that defective products are significantly generated depending on the welding torch, and the productivity of the valve per unit time is extremely low. Note that FIG.
In the figure, reference numeral 8 indicates a turntable for rotating the valve 1.

The present invention has been made in view of the above problems of the prior art. The welding material is uniformly ejected from a plurality of material ejection holes of the nozzle tip, so that the buildup is biased to a predetermined position. It is an object of the present invention to provide a welding torch that can be performed without the need and a build-up welding apparatus including the welding torch.

[0009]

The present invention for achieving the above object includes a welding torch body having a gas passage for introducing a plasma gas and a material passage for introducing a powdery welding material, and the above welding. A shield cap, which is annularly provided outside the tip of the torch body, forms a shield gas passage with the welding torch body, and the gas passage and the material passage provided at the tip of the welding torch body, respectively. A nozzle tip having a gas ejection hole and a plurality of material ejection holes communicating with each other, and ejecting the welding material and the plasma gas from each ejection hole,
In a welding torch configured to melt the welding material by the plasma gas converted into the gas plasma and attach it to a work, and further to inject a shield gas from the shield gas passage to shield the welded portion, A male screw is formed on the outer peripheral surface of the distal end portion of the welding torch body, and a tip holding nut that accommodates and locks the nozzle tip is screwed into the male screw. Further, the nozzle tip is formed with an annular groove for communicating the material passage and the plurality of material ejection holes,
The nozzle tip is formed with an annular protruding portion that fits into the tip of the gas passage, and the annular protruding portion is provided with a position regulating means for regulating the circumferential position of the nozzle tip. Can be. Further, the position regulating means is composed of a convex portion or a concave portion formed on the nozzle tip and a concave portion or a convex portion formed on the gas passage. A groove or fin extending in a direction along the flow of the shield gas is formed on the outer peripheral surface of the chip holding nut. The tip holding nut is made of the same material as the nozzle tip. The build-up welding apparatus of the present invention is a build-up welding apparatus for build-up welding dissimilar materials to a valve head of a material valve when manufacturing a valve for an intake valve or an exhaust valve of an internal combustion engine. And a welding table for rotating the material valve about its axis, and a welding torch of the present invention, wherein the welding torch has a jet port of the material valve supported by the rotating table. It is characterized in that it is provided so as to be opposed to the valve head.

[0010]

According to the first aspect of the invention, the nozzle tip is housed and held in the tip holding nut that is screwed into the welding torch body, and the nozzle tip can be circumferentially adjusted in position with respect to the welding torch body. As a result, the nozzle tip is positioned in the circumferential direction so that the material passage of the welding torch body is located, preferably in the middle, between the adjacent material ejection holes of the plurality of material ejection holes of the nozzle tip. As a result, the welding material flowing out from the material passage of the welding torch body is uniformly ejected from the plurality of material ejection holes. According to the second aspect of the invention, the welding material flown out of the material passage of the welding torch body once enters the groove of the nozzle tip and is then uniformly ejected from the plurality of material ejection holes. In the invention according to claim 3, since the annular projection of the nozzle tip is fitted into the gas passage of the welding torch body, the nozzle tip is stably supported on the welding torch body, and the nozzle tip is provided with a position regulating means. The position does not shift in the circumferential direction. In the invention according to claim 4, the position regulating means is formed by, for example, a concave portion provided in the welding torch main body and a convex portion provided in the nozzle tip, which is fitted into the concave portion, thereby forming the position regulating means. Can be simple. In the invention according to claim 5, the surface area of the outer peripheral surface of the chip holding nut is increased, and the cooling effect of the chip holding nut is enhanced. In the invention according to claim 6, since the nozzle tip and the tip holding nut which are exposed to high heat are made of the same material, the joint between them is excellent in durability, and the heat of the nozzle tip is transmitted to the tip holding nut. It will be easier. According to a seventh aspect of the present invention, there is provided a overlay welding apparatus for overlay welding different kinds of materials to a valve head of a material valve, which holds the material valve and rotates the material valve about its axis. A rotary table and a welding torch of the present invention are provided, and the welding torch is arranged so that its ejection port is located opposite to the valve head of the material valve supported by the rotary table. Overlay welding can be performed without bias on the material valve.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a front view of an embodiment of the overlay welding apparatus of the present invention, FIG. 2 is a plan view of the overlay welding apparatus of FIG. 1, and FIG. 3 is the welding of the present invention used in the overlay welding apparatus of FIG. FIG. 4A and FIG. 4B are vertical sectional views showing an embodiment of the torch.
FIG. 4 is a cross-sectional view taken along the line AA and a cross-section taken along the line BB of FIG. 3, respectively.

First, the overlaying apparatus of the present invention will be described. As shown in FIG. 1 and FIG. 2, the overlay welding apparatus of the present embodiment has a material valve stock means 10 in which a material valve A to be subjected to overlay welding is stored and a valve head of the material valve A. Welding means 20 for welding and the welding means 2
A material valve holding means 30 for holding the material valve A obliquely so that the valve head of the material valve A faces the welding torch 80 of 0 and rotating it about the axis.
The product valve stock means 50 for storing the product valve B which has been welded by the welding means 20 and the material valve A from the material valve stock means 10 to the material valve holding means 30 and the product valve B. Is provided from the material valve holding means 30 to the product valve stock means 50.

The material valve holding means 30 is provided with a rotary table means 31 with which the end surface of the material valve A on the valve head side abuts, and a valve stem of the material valve A, which is spaced apart obliquely above the rotary table means 31. Is pressed from above and the material valve A is pressed between the rotary table means 31 and the rotary table means 31.
And a valve mounting / positioning means 33 for positioning and mounting the material valve A substantially coaxially with the rotary shaft of the rotary table means 31.

The valve mounting / positioning means 33 has a support member 3 having a V-shaped groove formed at its tip end to abut the side surface of the valve stem of the material valve A to obliquely support the material valve.
4 and an axial moving means (for example, an air cylinder) 3 for moving the supporting member 34 in the axial direction of the material valve A.
5 and a radial moving means (for example, an air cylinder) 3 for moving the supporting member 34 in the radial direction of the material valve A.
6 is provided. The support member 34 is integrally fixed to the advancing / retreating member (for example, piston rod) of the radial moving means 36, and the radial moving means 36 is fixed to the advancing / retreating member (for example, piston rod) of the axial moving means 35. It is attached integrally, and when the advancing / retreating member of the axial moving means 35 is moved back and forth, the supporting member 34 moves together with the radial moving means 36 in the axial direction of the material valve A.

The valve transfer means 60 is constructed such that the material valve stock means 1 is centered on a point 62 on the fixed side 61.
From 0 to the material valve holding means 30, further from the material valve holding means 30 to the product valve stock means 50, and further from the product valve stock means 50 to the material valve stock means 10. The swing arm means 63, the rotating member 64 rotatably attached to the tip end side of the swing arm means 63, and the rotating member 64 at the outer peripheral portion of the rotating member 64 are attached at two positions sandwiching the rotating shaft. , Two chuck means 65, 66 for sandwiching the valve stem of the material valve A or the product valve B from the side surface.

A swivel base 67 is mounted on the fixed side 61 so as to swivel in a horizontal plane, and one end of the swing arm means 63 is connected to the upper part of the swivel base 67. The swing arm means 63 includes a first arm member 63a swingably connected to the swivel 67 and the first arm member 63a.
Second swingably connected to the tip of the arm member 63a of the
Arm members 63b, and the arm members 63a and 63b can change their swing angles independently of each other. In addition, a motor 68 is attached to the tip of the second arm member 63b.
It is attached so that the relative angle with respect to b can be changed, and the rotating member 64 is fixed to the rotating shaft of the motor 68.

The chuck means 65, 66 have two cylinders 69 arranged side by side in the rotation direction of the rotary member 64,
Each of the piston rods 69a of the cylinders 69 is constructed by attaching an abutting member that abuts the valve stem.

The material valve stock means 10 is provided with an alignment supply means (for example, a parts feeder) 11 for aligning and transporting the material valves A one by one.

The welding means 20 is provided with a guide column 21 standing upright in the vertical direction, a movable base 22 movably attached to the guide column 21 in the vertical direction, and a horizontal movement on the movable base 22. A movable table 23 that can be attached,
A bracket 24 fixed to the lower end of the moving table 23,
A welding torch 80 of the present invention, which will be described later, is attached to the tip of the bracket 24 in the vertical direction, and a powder supply means 89 for supplying the welding torch 80 with a powdered welding material. . The position of the welding torch 80 can be adjusted by moving the moving bases 22 and 23 in the vertical and horizontal directions.

Next, the welding torch of the present invention will be described. As shown in FIGS. 3 and 4, the welding torch 80 is
An electrode 7 (for example, a tungsten electrode) is provided in the central portion, and an inner cylinder 5 (made of, for example, phosphorous deoxidized copper) and an outer cylinder 4 as a welding torch body are provided outside the electrode 7.
Are coaxially arranged at predetermined intervals. The inner cylinder 5 has two material passages 6a and 6b which will be described later and extend in the axial direction. A gas passage 8 and a shield gas passage 9 are formed between the electrode 7 and the inner cylinder 5 and between the inner cylinder 5 and the outer cylinder 4, respectively. A shield gas such as argon gas and helium gas is supplied to the shield gas passage 9 from a shield gas supply means (not shown). The shield gas ejected from the shield gas passage 9 shields the welded portion (not shown). The gas passage 8 is a passage for introducing a plasma gas (for example, an inert gas such as argon gas or helium gas), and the two material passages 6a and 6b are for introducing a powdery welding material. Is the passage. In addition, at the front end (lower end) of the inner cylinder 5,
Nozzle tip 16 made of chrome, zirconium and copper described later
Is supported and fixed via the chip holding nut 12,
The nozzle tip 16 has material ejection holes 14a, 14 for ejecting a welding material and a plasma gas, respectively.
b, 14c, 14d and the gas ejection hole 11 are provided. The reason why the nozzle tip 16 is made of chromium, zirconium, and copper is that it has excellent electric conductivity, and particularly 400 to 50.
This is because the heat strength at 0 ° C. is high and a dense oxide scale can be easily formed on the surface so that arc rebound hardly occurs.

A feature of the welding torch 80 of this embodiment is that a male screw 15 is formed on the outer peripheral surface of the tip end portion of the welding torch body 5 which is a tapered surface. On the other hand, a taper surface similar to the taper surface of the welding torch body 5 is formed on the outer peripheral surface of the nozzle tip 16, and the nozzle tip 16 has the material passages 6a, 6b and the plurality of material ejection holes 14a, An annular groove 13 is formed for communicating with 14b, 14c and 14d. The tip holding nut 12 has a tapered upper inner peripheral surface,
The nozzle tip 16 is supported by the welding torch body 5 by accommodating and locking the nozzle tip 16 and screwing it into the male screw 15. In addition, the nozzle tip 16
Has an annular projecting portion 18 that fits into the tip of the gas passage 8. The annular projecting portion 18 is integrally provided with a protrusion (projection) 17 for restricting the circumferential position of the nozzle tip 16. It is provided in. The protrusion 17 slidably fits into a groove (recess) 17a formed in the wall surface of the gas passage 8 of the welding torch body 5. The convex portion 17 provided on the nozzle tip 16 and the concave portion 17a provided on the welding torch body 5 constitute a position regulating means. The nozzle tip 16 is positioned in the circumferential direction so that the material passages 6a, 6b of the welding torch body 5 are located in the middle of the adjacent material ejection holes of the plurality of material ejection holes 14a, 14b, 14c, 14d of the nozzle tip 16. regulate. In addition, reference numeral 19 indicates an abutting portion formed on the nozzle tip 16 to the welding torch body 5.

On the outer peripheral surface of the chip holding nut 12,
In order to enhance the cooling effect, a plurality of grooves 12a having a semicircular cross section extending in the direction along the flow of the shield gas are formed. Note that fins may be formed instead of the grooves. The tip holding nut 12 is made of the same material as the nozzle tip 16. This allows
These joints have excellent durability, and the heat of the nozzle tip 16 is easily transferred to the tip holding nut 12.

Welding torch 80 constructed as described above
Then, the plurality of material ejection holes 14a, 1 of the nozzle tip 16
The material of the welding torch body 5 is fixed by positioning the nozzle tip 16 in the circumferential direction so that the material passages 6a, 6b of the welding torch body 5 are located between the adjacent material ejection holes of 4b, 14c, 14d. The welding material that has flowed out from the passages 6a and 6b is once in the annular groove 1 of the nozzle tip 16.
After entering 3, a plurality of material ejection holes 14a, 14b, 14
It is jetted uniformly from c and 14d. Further, since the annular projection 18 of the nozzle tip 16 is fitted into the gas passage 8 of the welding torch body 5, the nozzle tip 16 is stably supported on the welding torch body 5. Also, the tip holding nut 1
The heat of 2 is transmitted to the welding torch main body 5, and the cooling effect of the tip holding nut 12 is enhanced.

During welding, spatter is scattered near the tip of the welding torch 80, which causes the material ejection holes 14a, 1
4b, 14c, 14d are clogged, the material ejection hole 14
The welding material is vigorously ejected from a, 14b, 14c, 14d, so that the material ejection holes 14a, 14b, 1
When the insides of 4c and 14d are worn and their diameters are enlarged, the nozzle tip 16 is replaced with a new one.

In the above embodiment, the welding torch body 5
The welding material flowing out from the material passages 6a, 6b of FIG. 1 once entered the annular groove 13 of the nozzle tip 16 and was then uniformly ejected from the plurality of material ejection holes 14a, 14b, 14c, 14d. However, it is not limited to this. That is, as shown in FIG. 5, a plurality of (4 in this embodiment) material passages 6a, 6c (4 in this embodiment) are provided at equal intervals (90 ° intervals in this embodiment) in the welding torch body 5 without providing an annular groove. Two material passages form (not shown), and each material passage 6a,
Material ejection holes 14a and 14c may be formed in the nozzle tip 16 in the same number as the material passages 6a and 6c so as to face the material 6c. As a result, the welding material flowing out of the material passages 6a, 6c immediately enters the material ejection holes 14a, 14c and is ejected.

Again, as shown in FIG. 1, the powder supply means 89 is connected to the material passage 85 (see FIG. 3),
The hopper 26a for storing the powdery welding material and the welding material in the hopper 26a are dropped onto the knurled rotary roller 26b, and the rotary roller 26b rotates to collect the powder accumulated on the knurled surface with argon gas. Pressure feed pipe 26c for pressure feeding to the material passage 85 of the welding torch 80
And a weight measuring means (for example, a load cell) (not shown) for measuring the weight of the hopper 26a and adjusting the supply amount of the welding material to an appropriate amount. The weight measuring means measures the total weight of the weight of the hopper 26a itself and the stored welding material, and the weight of the welding material for overlay welding on one material valve A is the total weight. Since it is too small for the weight and cannot be measured accurately,
The weight of the welding material used is determined from the weight difference before and after the overlay welding is performed a plurality of times (for example, 100 times), the weight is compared with a preset reference value, and the knurled rotary roller is obtained. The rotation speed of 26b is adjusted to adjust the amount of welding material pumped.

The rotary table means 31 includes a swing block 37 rotatably held by the guide column 21 by a support portion 37a, a rotary table 38 rotatably attached to the swing block 37, and a swing table. It is fixed to the block 37 and has a rotation shaft 38 and a motor 39 connected by a belt.

The valve attaching / detaching means 32 is the rotary table 38.
An advancing / retreating block 42 which is coaxially arranged with a groove 41 into which a valve stem is inserted, and a cylinder 43 which is supported by the swing block 37 and moves the advancing / retreating block 42 coaxially with the rotary table 38. I have it.

The product stock means 50 has a dolly 51 having wheels 52 attached to the lower surface thereof, and a box-type pallet 53 mounted on the dolly 51 and having an open top.
And a sampling chute 54 for taking out a sample of the product valve B every fixed number.

The rotary table 38 of the material valve holding means 30
A valve attachment surface polishing device (not shown) for polishing the upper surface of the rotary table 38 is provided near the rotary table 38 so as to be movable between a position in contact with the rotary table 38 and a position away from the rotary table 38. This valve mounting surface polishing device is provided for flattening the valve mounting surface to which the welding beet is attached.

Reference numeral 70 in the figure indicates the operation of the valve transfer means 60 (for example, the gripping position by the chucking means 65, 66, the supply position to the material valve holding means 30, the discharge position to the product stocking means 50, and the respective operations. Control means for controlling the valve transportation means for controlling the standby time, the sampling timing, the number of samples, etc., and 71 is the welding means 20.
Is a cooling water circulating means for circulating cooling water through the material valve holding means 30, 72 is a welding power supply device for supplying power to the welding means 20, and 73 is a position of the welding torch 80 of the welding means 20, plasma gas conditions, etc. Welding conditions, powder supply conditions by powder supply means 89, material valve holding means 30
Is a total control means for controlling the rotation conditions of the material valve A, etc., and 74 is an operation panel for issuing a command to the valve transfer means control means 70, the cooling water circulation means 71, the welding power source device 72 and the general control means 73. Is. The operation panel 74 has a display 74a for displaying various information,
A volume knob 74b for continuously changing the current value of the welding power source device 72, the supply amount of the powder supply means 89, and the rotation speed of the rotary table 38 is provided.

Next, the operation of the overlay welding apparatus of this embodiment will be described. First, the shape of the valve used for overlay welding,
A material, a material to be built up on the valve, and the like are input from the operation panel 74. As a result, the optimum operation program for the valve to be overlay welded is selected from the plurality of operation programs set for each valve. According to this operation program, for example, the operation of the valve conveying means 60 (for example, the gripping position by the chucking means 65, 66, the supply position to the material valve holding means 30, the discharge position to the product stocking means 50, the waiting time between each operation) , Sampling timing, number of samples, etc.), welding conditions such as the position of the welding torch 80 of the welding means 20 and plasma gas conditions, powder supply conditions by the powder supply means 89, rotation of the material valve A by the material valve holding means 30. Conditions etc. are set. It should be noted that the current value of the welding power supply device 72, the supply amount of the powder supply means 89, and the rotary table 38 are controlled by the volume knob 74b by the display on the display 74a of the operation panel 74, visual inspection of the actual welding condition, or the like.
The rotation speed of may be changed continuously.

Thereafter, a series of operations as described below is automatically performed by the selected operation program. Therefore, even when overlay welding is performed on multiple types of valves made of various shapes and materials, simple operations such as selecting a preset operation program without setting various conditions are sufficient, and setup work can be performed. Easy to do.

That is, as shown by the chain double-dashed line in FIG. 1, the swivel base 67 on the fixed side 61 is swung to the material valve stock means 10 side, and the swing arm means 63 is swung about one point 62. Then, by rotating the rotating member 64 attached to the tip of the swing arm means 63, the chuck means 65 is also directed toward the material valve stock means 10 side. Then, the alignment supply means 11 is operated to sequentially supply and supply the material valves A, and the valve stems of the supplied material valves A are clamped and held from the side surface by the chuck means 65. The holding position is set by the operation program so as to be an appropriate position according to the shape (length, thickness, etc.) of the valve.

Next, as shown by the solid line in FIG. 1, the swivel base 67 is swung to the side of the material valve holding device 30, and the swing arm means 63 is also moved to the material valve holding device 3 in the same manner.
Swing toward the 0 side. At this time, the motor 64 is rotated with respect to the second arm member 63b to move the chuck means 6
The material valve A gripped by 5 is positioned so as to sandwich the rotation axis of the rotating member 64 with respect to the material valve holding means 30.

Next, the motor 68 is rotated to rotate the rotating member 6
4 is rotated 180 ° so that the material valve A sandwiched by the chuck means 65 is positioned between the rotary table 38 of the material valve holding means 30 and the advancing / retreating block 42.

Next, the axial moving means 35 is connected to the material valve A.
When the tip end portion of the support member 34 reaches a predetermined position by moving the support member 34 in the axial direction, the movement is stopped. The stop position is set in correspondence with the position of the center of gravity of the valve, and is set in advance by the operation program according to the shape of the valve. Next, the radial direction moving means 36 is brought closer to the radial direction of the material valve A so that the tip of the support member 34 is moved to the material valve A.
Abut the outer surface of the valve stem of. After that, the clamping by the chuck means 65 is released, and the swing arm means 63 is moved so as to be slightly separated from the material valve A. As a result, the holding of the material valve A by the chuck means 65 is released, and the material valve A is held in an inclined state by the support member 34. After that, the radial direction moving means 36 is further moved in the radial direction of the material valve A, and the material valve A is moved in the radial direction of the rotary table 38 by the support member 34, so that the axial center of the material valve A and the rotary table 38 are moved. Make it coaxial with the axis of rotation. The movement amount of the radial direction moving means 36 is also preset by the operation program.

Here, when the axis center is adjusted by the swing arm means 63, it is difficult to adjust the axis center by moving in an arc shape due to the nature of the movement such as swing, but the axial direction moving means 35. Since the valve mounting and positioning means 33 including the radial movement means 36 and the radial movement means 36 is used, the axis of the material valve A and the rotation axis of the rotary table 38 can be made coaxial with each other with high accuracy, and will be described later. When overlay welding is performed on the valve head as described above, it is possible to form a high-quality overlay weld portion having a uniform thickness in the circumferential direction.

Next, the cylinder 43 is extended and driven to move the advancing / retreating block 42 forward to the rotary table 38 side. As a result, the upper portion of the valve stem of the material valve A is inserted into the groove 41 formed in the central portion of the advancing / retreating block 42.
The material valve A is pressed and held between the bottom portion of No. 1 and the rotary table 38. Then, the radial direction moving means 36 is driven to be reduced to retract the support member 34 from the outer surface of the material valve A, and then the rotary table 38 is rotated by rotationally driving the motor 39, whereby the material valve A is rotated. Begins to rotate with.

Material valve holding means 3 of the material valve A
The movable table 22 is moved along the guide pillar 21 in parallel with or before and after the attachment to the 0.
Move 3 horizontally. As a result, the welding torch 80 fixed to the moving table 23 is moved to a predetermined position, and a position facing the valve head of the material valve A held (or held) by the material valve holding means 30 from above. Is located in. In this case, the moving amounts of the moving bases 22 and 23 are also preset by the operation program according to the shape of the material valve and the like.

Then, a current is supplied from the welding power source 72 between the electrode 83 of the welding torch 80 and the material valve A (material valve holding means 30) to generate a plasma arc between the electrode 83 and the material valve A. At the same time, the powder supply means 89 is driven to supply a predetermined welding material into the material passage 85, and it is ejected from the ejection ports 96b ... Of the tip 92. The jetted powder material is melted by the plasma arc and is welded to the valve head of the material valve A by overlay welding. Here, since the material valve A is obliquely supported and rotated by the material valve holding means 30, the welding material does not flow out to the outside and the welding material is built up uniformly in the circumferential direction of the valve head. Therefore,
It is possible to form a high-quality build-up weld portion that is homogeneous and has little variation.

On the other hand, while the overlay welding is being performed by the welding torch 80, the material valve A for the overlay welding is conveyed from the material valve stock means 10 to the material valve holding means 30 in the vicinity thereof. come. That is, after the material valve A is supported by the support member 34, the material valve A is
Of the chuck means 66 attached to the rotary member 64 of the valve transfer means 60 by interlocking the swing of the swing arm means 63, the swing of the swivel base 67, and the rotation of the rotary member 64. The material valve A is opposed to the material valve A of the material valve stock means 10, the material valve A is sandwiched by the chuck means 66, and the swivel 67, the swing arm member 63, and the like are returned. At this time, the material valve A sandwiched by the chuck means 66 is positioned so as to sandwich the rotation axis of the rotating member 64 with respect to the material valve holding means 30, and the material valve A is located at a position facing the material valve A being welded. , So that the chuck means 65 not holding the material valve A comes.

Next, when the overlay welding is completed, the motor 39
To stop the rotation of the turntable 38. Then, the swing arm means 63 is moved in a direction in which the swing arm means 63 is slightly closer to the product valve B, which has been slightly welded by overlay welding, and the rotary member 64 is moved.
The chuck means 65 attached to the product valve which does not hold the material valve is moved toward the product valve B, and the chuck means 65 is arranged so as to sandwich the valve stem of the product valve B. Next, the product valve B is sandwiched and held by the chuck means 65. Next, the cylinder 43
Is reduced to move the advancing / retreating block 42 obliquely upward to release the pressing of the product valve B by the advancing / retreating block 42. In this state, the rotating member 64 is rotated by 180 ° by rotating the motor 68. Then, the product valve B sandwiched by the chuck means 65 moves to a position sandwiching the rotary member 64 and the chuck means 6
The material valve A sandwiched by 6 is located between the rotary table 38 and the advancing / retreating block 42. Then, the material valve A is installed coaxially with the rotary shaft of the rotary table 38 by the same procedure as described above, and the overlay welding is applied to the valve head of the material valve A in the same manner as described above.

Material valve holding means 3 of this material valve A
The product valve B held between the chuck means 65 before and after being held at 0 is conveyed to the product valve stock means 50. That is, the swing of the swing arm means 63 and the swivel base 6
By the turning of 7, the rotating member 64 attached to the tip end side of the swing arm means 63 as shown by the chain double-dashed line in FIG.
Is moved above the pallet 53 of the product valve stock means 50. Then, the clamping of the product valve B by the chuck means 65 is released, and the product valve B is stored in the pallet 53 by a natural drop. Here, the product valve B has been welded to the overlay immediately before and is dropped from an excessively high position. The overlay welded portion is scratched or cracked, or the portion other than the overlay welded portion is scratched. Since a problem such as occurrence occurs, the swing arm means 63 is further swung to move the height of the product valve B sandwiched by the chuck means 65 as close to the pallet 53 as possible, and then dropped. To do. Also, pallet 5
The product valves B are so-called stuffed in 3 without being aligned, but when the product valves B stored in the pallet 53 are few, they are dropped at a low position,
As the product valves B gradually accumulate in the pallet 53, movement control is performed so that the product valves B are gradually dropped at a higher position. As a result, the product valve B is smoothly stored in the pallet 53.

Next, after releasing the product valve B, the swing arm means 63 and the swivel base 67 are swung so as to sandwich the new material valve A, and the rotation provided at the tip of the swing arm means 63 is performed. The member 64 is the material valve stock means 1
Toward 0, the material valve A is clamped by the chuck means 65 provided on the rotating member 64 in the same manner as in the above-described procedure, and the swinging of the swinging arm means 63 and the swivel base 67 are performed in the same manner as in the above-described procedure. The material valve A is conveyed toward the material valve holding means 30 by turning. After that, by repeating the above-mentioned operation again, overlay welding can be continuously performed on the valve head of the material valve A.

In the overlay welding apparatus according to the present embodiment, the material valve A is held by the material valve holding means 30 and the overlay welding welding is performed by the welding torch 80. Since the operations such as transporting or discharging the product valve B to the product valve stock means 50 are simultaneously performed in parallel, the loss time for supplying the material valve A can be reduced. The productivity of overlay welding can be greatly increased.

[0047]

Since the present invention is configured as described above, it has the following effects. According to the invention described in claims 1 and 2, the welding material can be uniformly ejected from the plurality of material ejection holes of the nozzle tip, whereby the converging effect of the plasma is enhanced and the padding is not biased to a predetermined position. It can be performed uniformly. According to the invention described in claim 3, in addition to the above effects, since the nozzle tip is fitted to the welding torch body, the support of the nozzle tip on the welding torch body is stabilized, and the nozzle tip is circumferentially moved by the position regulating means. It does not shift to. The invention according to claim 4 can achieve the position regulating means by a simple fitting of the convex portion or the concave portion. Since the cooling effect of the tip holding nut is enhanced, the heat of the nozzle tip can be efficiently released through the nut. Claim 6
The invention described in, by making the nozzle tip and tip holding nut exposed to high heat the same material, the joints thereof are excellent in durability, and the heat of the nozzle tip is easily transmitted to the tip holding nut, Moreover, the heat of the tip holding nut is transferred to the welding torch body, and as a result, the nozzle tip cooling effect is enhanced. In the overlay welding device according to the seventh aspect, a large amount of overlay valves for intake valves or exhaust valves of an internal combustion engine can be overlayed with high quality in a short time.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the overlay welding device of the present invention.

2 is a plan view of the overlay welding apparatus of FIG. 1. FIG.

FIG. 3 is a vertical sectional view showing an embodiment of the welding torch of the present invention used in the overlay welding apparatus of FIG.

4A is a sectional view taken along the line AA of FIG. 3, and FIG. 4B is a sectional view taken along the line BB of FIG.

FIG. 5 is a sectional view of another embodiment of the welding torch of the present invention.

FIG. 6 is a vertical sectional view of a conventional welding torch.

7A is a sectional view taken along the line AA of FIG. 6, and FIG. 7B is a sectional view taken along the line BB of FIG.

FIG. 8 is a diagram showing an uneven build-up caused by a conventional welding torch.

[Explanation of symbols]

A material valve B product valve 1 valve 2 valve head 3, 3a, 3b overlay 4 outer cylinder 4a shield cap 5 inner cylinder (welding torch body) 6a, 6b material passage 7 electrode 8 gas passage 9 shield gas passage 10 material valve stock Means 11 Gas ejection hole 12 Tip holding nut 12a Groove 13 Annular groove 14a, 14b, 14c, 14d Material ejection hole 15 Male screw 16 Nozzle tip 17 Protrusion (convex portion) 17a Groove (concave portion) 18 Fitting portion 19 Abutting portion 20 Welding Means 21 Guide column 22, 23 Moving table 24 Bracket 30 Material valve holding means 31 Rotary table means 32 Valve attaching / detaching means 33 Valve mounting positioning means 34 Supporting member 35 Axial direction moving means 36 Radial moving means 37 Swinging block 37a Supporting part 38 Turntable 39 Motor 41 Groove 42 Retracting block 43 Cylinder 50 Product valve stock means 51 Truck 52 Wheels 53 Pallet 54 Sampling chute 60 Valve transfer means 61 Fixed side 62 One point 63 Swing arm means 63a First arm member 63b Second arm member 64 Rotating member 65, 66 Chuck means 67 Swivel base 68 Motor 69 Cylinder 69a Piston rod 70 Control means for valve transfer means 71 Cooling water circulation means 72 Welding power supply device 73 General control means 74 Operation panel 74a Display 74b Volume knob 80 Welding torch 89 Powder supply means

Claims (7)

[Claims] 1. A welding torch body having a gas passage for introducing a plasma gas and a material passage for introducing a powdery welding material; and the welding provided in an annular shape outside the tip of the welding torch body. A shield cap that forms a shield gas passage with the torch body, and a nozzle tip having a gas ejection hole and a plurality of material ejection holes that are provided at the tip of the welding torch body and that communicate with the gas passage and the material passage, respectively. And ejecting the welding material and the plasma gas from the respective ejection holes, melting the welding material by the plasma gas turned into the gas plasma and adhering it to the work, and further shielding gas A welding torch configured to be injected from a shield gas passage to shield a welded portion. Welding torch to the front end portion outer peripheral surface is formed an external thread, the male screw, tip retaining nut for locking to accommodate the nozzle tip is characterized in that it is screwed. 2. The welding torch according to claim 1, wherein the nozzle tip is formed with an annular groove for communicating the material passage with the plurality of material ejection holes. 3. The nozzle tip is formed with an annular protrusion that fits into the tip of the gas passage, and the annular protrusion has a position regulation for regulating the circumferential position of the nozzle tip. Welding torch according to claim 1 or 2, wherein means are provided. 4. The position regulating means is composed of a convex portion or a concave portion formed on the nozzle tip and a concave portion or a convex portion formed on the gas passage.
Welding torch described in. 5. The welding torch according to claim 1, wherein a groove or a fin extending in a direction along the flow of the shield gas is formed on an outer peripheral surface of the tip holding nut. 6. The welding torch according to claim 1, wherein the tip holding nut is made of the same material as the nozzle tip. 7. A build-up welding apparatus for build-up welding dissimilar materials to a valve head of a raw material valve when manufacturing a valve for an intake valve or an exhaust valve of an internal combustion engine, which holds the raw material valve, A rotary table for rotating the material valve about its axis, and a welding torch according to any one of claims 1 to 6, wherein the welding torch supports its ejection port on the rotary table. A build-up welding device, which is provided so as to face a valve head of the material valve.