JPH07214312A - Equipment for cladding by welding - Google Patents

Abstract

PURPOSE:To prevent gnawing of a sliding part by moving forward and back ward a forward and backward block coaxially with a turntable means and thereby inserting the block into and in slidable contact with the hollow part of a cylinder. CONSTITUTION:With a welding torch held by a means 30 for holding an unprocessed valve A ('valve'), the valve is rotated obliquely so that the head of the valve oppositely faces the welding torch. The valve holding means 30 is provided with a turntable means 31 and the valve attaching/detaching means 32 which, installed in the oblique upper part of the turntable means, presses the stem of the valve from above and holds it freely detachably between the means 32 and the turntable means 31. The valve detaching means 32 is provided with a forward/backward block 42 in which a groove 41 is formed for the valve stem to be inserted, a forward/backward driving means 43 for moving the block 42 forward/backward, and a cylinder 43b which is fixed on the fixed side 43a of the driving means 43, and which the forward/backward block 42 is inserted in nearly slidable contact state into the hollow part. Consequently, the valve is surely pressurized and held without putting its positional precision out of order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a build-up welding apparatus for build-up welding dissimilar materials to a valve head of an intake valve or an exhaust valve of an internal combustion engine.

[0002]

2. Description of the Related Art As is well known, a valve head of an air supply valve or an exhaust valve of an internal combustion engine is repeatedly contacted with a valve seat at high speed, so that the valve head is required to have high wear resistance. Therefore, as shown in FIG. 9, a material having high wear resistance (for example, Co—Cr—W) is used for the valve head 2 of the valve 1.
(C-based alloy) is overlay welded (see 3 in the figure), and then the overlay welded portion is machined (for example, ground) to have a desired shape.

Here, for overlay welding on the valve head, a holding jig provided with a rotary table and a pressing mechanism such as a cylinder arranged above the rotary table is used to rotate the holding jig. A valve for overlay welding (hereinafter referred to as a material valve) is placed on the table, and the end portion of the valve stem is pressed by a pressing mechanism from above and is held between the rotary table and the pressing mechanism. It is conceivable to perform overlay welding while rotating the turntable.

[0004]

However, in the conventional holding jig, since the pressing mechanism such as the cylinder is exposed, it is necessary to perform overlay welding by using powdery welding material for overlay welding, for example. In such a case, there is a problem in that the powdery welding material enters the sliding portion of the cylinder or the like to cause galling or the like on the sliding portion of the cylinder and the pressing mechanism may not operate smoothly.

Further, in the conventional holding jig, it is general that the pressing mechanism such as a cylinder has some play in a direction intersecting with the advancing / retreating direction. However, a pressing mechanism having such play is used. When the material valve is held, the axis of the material valve is offset from the rotary shaft of the rotary table when the material valve is pressed by the pressing mechanism, even if the material valve is coaxially positioned with respect to the rotary shaft of the rotary table. There is a problem of being mindful. In this way, if it is eccentric with respect to the rotary shaft of the rotary table, the distance between the welding torch and the material valve will change with rotation during overlay welding,
It becomes impossible to form a build-up weld having a uniform thickness.

The present invention has been made in view of the above circumstances, and it is possible to prevent the powdery welding material injected from the welding torch from entering the sliding portion of the advancing / retreating drive mechanism and to prevent galling of the sliding portion. The material valve can be prevented in advance, and even if there is some play in the sliding portion of the advancing / retreating drive mechanism in the direction intersecting the advancing / retreating direction, the material valve coaxially positioned with respect to the rotation axis of the rotary table means. It is an object of the present invention to provide a build-up welding device that can surely press and hold the position welding without deteriorating the positional accuracy thereof.

[0007]

A 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 an intake valve or an exhaust valve of an internal combustion engine, A welding torch for overlay welding on a valve head of a material valve to be overlay welded, and a material valve is held obliquely and rotated about an axis so that the valve head of the material valve faces the welding torch. A material valve holding means, wherein the material valve holding means is provided with a rotary table means with which an end surface of the material valve on the valve head side abuts, and a valve stem of the material valve provided obliquely above the rotary table means. And a valve attaching / detaching means for holding the material valve detachably between the rotary table means and the rotary table means.
A substantially cylindrical advancing / retreating block arranged coaxially with the rotary table means and having a groove into which a valve stem is inserted, and an advancing / retreating drive means for advancing / retreating the advancing / retreating block coaxially with the rotary table means, A cylinder fixed to the fixed side of the advancing / retreating drive means, and having the hollow portion into which the advancing / retreating block is inserted in a substantially slidable contact state.

[0008]

According to the overlay welding apparatus of the present invention, the valve table side end surface of the material valve is brought into contact with the rotary table means of the material valve holding means, and the valve stem of the material valve is pressed from above by the valve attaching / detaching means. The material valve is detachably held between the rotary table means and the valve head so that the valve head faces the welding torch, and the valve head of the material valve is overlay welded to the valve head of the material valve by the welding torch and the product valve (hereinafter, Product valve) is manufactured.

Here, since the columnar advancing / retreating block is inserted into the hollow portion of the cylinder fixed to the fixed side of the advancing / retreating driving means in a substantially slidable contact state, the sliding portion of the advancing / retreating driving means and the cylinder move forward and backward. The powdery welding material, which is surrounded by and is sprayed from the welding torch, is prevented from entering the sliding portion of the advancing / retreating drive means, and galling of the sliding portion is prevented in advance. Further, even if there is some play in the sliding portion of the advancing / retreating drive means in the direction intersecting the advancing / retreating direction, the advancing / retreating block can be moved coaxially with respect to the rotation axis of the rotary table means, and the coaxial positioning is possible. It is possible to reliably press and hold the material valve without deteriorating the positional accuracy of the material valve.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A build-up welding apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

The overlay welding apparatus of this embodiment includes a material valve stock means 10 for storing a material valve A to be subjected to overlay welding, and a welding means 20 for overlay welding on a valve head of the material valve A. 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 25 of the welding means 20 and rotating it about an axis, and overlay welding by the welding means 20. The product valve stock means 50 for storing the removed product valve B and the material valve A from the material valve stock means 10 to the material valve holding means 30 and the product valve B for the material valve holding means 3
And a valve transfer means 60 for transferring the product from 0 to the product valve stock means 50.

The material valve holding means 30 is provided with a rotary table means 31 against 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 against 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 and. 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 conveying means 60 has the material valve stock means 10 centered on a point 62 on the fixed side 61.
To the material valve holding means 30, from the material valve holding means 30 to the product valve stock means 50, and from the product valve stock means 50 to the material valve stock means 10. The moving arm means 63, the rotary member 64 rotatably attached to the tip end side of the swing arm means 63, and the rotary member 64 at the outer peripheral portion of the rotary member 64 are attached at two positions sandwiching the rotary shaft. Material valve A or product valve B
And two chuck means 65 and 66 for sandwiching the valve stem from the side.

On the fixed side 61, a swivel base 67 is mounted which can 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
The arm members 63b and 63b are provided, and the swing angles of the arm members 63a and 63b can be changed independently of each other. A motor 68 is attached to the tip of the second arm member 63b so as to change the relative angle with the second arm member 63b. 64 is fixed.

As shown in FIG. 2, the chuck means 65 and 66 have two cylinders 69 arranged side by side in the rotational direction of the rotary member 64, and each piston rod 69a of these cylinders 69 has a valve stem. A contact member that abuts is attached.

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 25 is attached to the tip of the bracket 24 in the vertical direction, and a powder supply means 26 for supplying the welding torch 25 with a powdered welding material. The position of the welding torch 25 can be adjusted by moving the moving bases 22 and 23 in the vertical and horizontal directions.

As shown in FIG. 3, the welding torch 25 has a double-tube shape, and the powdery welding material is pressure-fed by argon gas or the like into the inner pipe 25b, so that the inner pipe 25b and the outer pipe are not in contact with each other. It is configured such that the welding gas is pressure-fed to and from 25a. The tip 2 of the inner pipe 25b is made of copper.
5c is fixed, a through hole 25e for inserting the electrode 25d is formed at the center of the tip 25c, and a through hole 25f for injecting a powdery welding material is formed on the peripheral side of the tip 25c. A high voltage is applied to the welding material injected from the through hole 25f by the electrode 25d so that the welding material is melted and injected toward the valve head. Here, since the diameter of the through hole 25f increases as the welding material is injected, the through hole 25f is replaced with a new one after being used for a predetermined time.

The powder supply means 26 drops the welding material in the hopper 26a, which stores the powdery welding material, and the knurled rotating roller 26B, and the rotating roller 26b rotates. Welding torch 25 with powder accumulated on the knurled surface by argon gas flow
It is provided with a pressure feeding pipe 26b for pressure feeding to and a weight measuring means (not shown) (for example, a load cell) for measuring the weight of the hopper 26a to adjust 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 the weight is small and cannot be measured accurately, the weight of the welding material used was determined from the weight difference before and after the overlay welding was performed multiple times (for example, 100 times), and this weight was preset. The rotation speed of the knurled rotary roller 26b is adjusted as compared with the reference value, and the amount of welding material pumped by this is adjusted.

As shown in FIG. 4, the rotary table means 31 has a support portion 37a (see FIG. 1) on the guide column 21.
The swing block 37 rotatably held by the swing block 37 and the turntable 3 rotatably attached to the swing block 37.
8, a cooling pipe (shaft member) 47 that rotatably supports the rotary base 38 via bearings 46, and a rocking block 37. The rotary shaft is connected to the rotary base 38 via a belt 39a. The motor 39 and the cooling pipe 47 to the bearing 46.
And two grounding mechanisms 48 that extend in the radial direction and that ground without passing through. The cooling pipe 47 is the inner pipe 4
It has a double tube structure composed of 7a and an outer tube 47b.

The rotary table 38 holds a box-shaped frame 44 which is rotatably attached to the cooling pipe 47 while maintaining a hermetically sealed state so that the powdery welding material cannot enter the periphery of the cooling pipe 47. It is provided with a base metal block 45 fixed to the upper part of the box-shaped frame 44. An elastic seal material 44b made of a non-conductive material such as rubber is interposed between the box frame 44 and the base metal block 45.
Further, an elastic seal member 44e made of a non-conductive material is also interposed between the lower portion of the box-shaped frame and the pulley 39b rotated by the belt 39a.

A photoelectric sensor 44c is fixed to the lower portion of the box-shaped frame 44 of the rotary table 38, and the cooling pipe 47 is provided between the light receiving portion and the light emitting portion of the photoelectric sensor 44c.
4 fixed to the outer circumference of the disk through a fixing block 44i
The peripheral portion of 4d is arranged. Disc 44
As shown in FIG. 6, d has a slit 44f formed by equally dividing the circumference into eight equal parts. This slit 44f
The rotation angle of the box-shaped frame 44 of the turntable 38 can be detected by the photoelectric sensor 44c facing the above.

An umbrella-shaped member 44 having a flange 44g formed on the outer periphery of a cooling pipe 47 located below the bearing 46 inside the box-shaped frame 44 of the rotary table 38.
h is fixed, and the flange 4 of this umbrella-shaped member 44h
The lower surface of 4 g comes into contact with a circumferentially extending protrusion 48 g formed on an outer cylinder 48 a of the earthing mechanism 48, which will be described later. The umbrella-shaped member 44h and the protrusion 48g correspond to the grease adhesion preventing mechanism of the present invention.

The grounding mechanism 48 has a contact 48b made of a conductive material (for example, carbon), the inner end of which is in contact with the outer pipe 47b of the cooling pipe 47, and the contact 48b.
An outer cylinder 48a inserted movably in the axial direction, a biasing mechanism (coil spring) 48c for biasing the contactor toward a support member 48d supporting the cooling pipe 47, and the contactor 48b. And a terminal 48e for grounding. The grounding mechanism 4 is provided on the side surface of the box-shaped frame 44.
8 is formed with a through hole 44a for mounting the outer cylinder 48.
A flange 48f is formed on a, and by bringing the flange 48f into contact with the peripheral portion of the through hole 44a formed in the box frame 44 and bolting the same, the powdery welding material cannot enter. Has been inserted in.

The base metal block 45 has a flange portion 45a for bolting to the upper portion of the box frame 44.
And the cylindrical portion 4 continuously provided on the upper portion of the flange portion 45a.
5b and 45c. In addition, the cylindrical portion 45
b has a cylindrical shape, and the inner pipe 4 of the cooling pipe 47 is provided inside.
7a is stored with the ends thereof facing the back surface of the cylindrical portion 45c. The cooling water supplied from the inner pipe 47a cools the columnar portion 45c and then flows into the outer pipe 47b. The diameter D of the cylindrical portion 45c is
It is formed slightly larger than the diameter d of the valve head of the material valve A.

As shown in FIG. 1, the valve attaching / detaching means 3
Reference numeral 2 denotes an advancing / retreating block 42 arranged coaxially with the rotary table 38 and having a groove 41 formed at the center for inserting a valve stem.
And a forward / backward drive means (cylinder) 43 supported by the swing block 37 to move the forward / backward block 42 coaxially with the rotary table 38. The forward / backward block 42 is shown in FIG.
, The piston rod 43c of the cylinder 43, as shown in FIG.
A block main body 42b screw-connected to the block main body 42b, a cylindrical portion 42a provided on the outer surface of the block main body 42b, and a lower end of the block main body 42b rotatably connected via a bearing 42c. The rotary member 41a is provided with the groove 41 into which the stem is inserted. A cylinder 43b made of stainless steel is fixed to the frame 43a to which the cylinder 43 is fixed, and the advancing / retreating block 42 has the cylindrical portion 42a and the inner surface of the cylinder 43b in the hollow portion of the cylinder 43b. It is inserted in a sliding contact state (or with a slight gap maintained).

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 upper opening.
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 mounting surface polishing device (not shown) for polishing the upper surface of the rotary table 38 is provided near the base plate 4 of the rotary table 38.
5 is provided so as to be movable between a position in contact with the upper surface of 5 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 71 in FIG. 2 is a cooling water circulating means for circulating cooling water to the welding means 20 and the material valve holding means 30, 72 is a welding power source device for supplying power to the welding means 20, and 73 is a welding power source device. Position of welding torch 25 of welding means 20, welding conditions such as plasma gas conditions, powder supply means 2
6 is a comprehensive control means for controlling the powder supply conditions by 6, the rotation condition of the material valve A by the material valve holding means 30, and the like, and 74 is an operation panel for issuing commands to these.

Next, the operation of the overlay welding apparatus of this embodiment will be described.

First, the shape and material of the valve to be overlay welded, the material to be overlayed 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 25 of the welding means 20 and plasma gas conditions, powder supply conditions by the powder supply means 26, rotation of the material valve A by the material valve holding means 30. Conditions etc. are set.

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 so that the material valve A gripped by the chuck means 65 is located at a position sandwiching the rotary shaft of the rotating member 64 with respect to the material valve holding means 30. To

Next, the motor 68 is rotated to rotate the rotating member 6
4 is rotated 180 ° to position the material valve A sandwiched by the chuck means 65 between the base metal block 45 and the advancing / retreating block 42 of the rotary table 38 of the material valve holding means 30.

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.

The forward / backward block 42 is a frame 43.
Since the cylindrical portion 42a and the inner surface of the cylinder 43b are inserted into the hollow portion of the cylinder 43b fixed to a in a slidable contact state (or with a slight gap maintained), the piston rod 42c of the cylinder 43 is It is housed in a sealed state between 43b and the cylindrical portion 42a, which prevents the powdery welding material injected from the welding torch 25 from entering the sliding portion of the cylinder 43, and galling the cylinder 43, etc. Can be prevented in advance.

Further, since the cylinder 43b functions as a guide for the advancing / retreating block 42, even if the piston rod 43c of the cylinder 43 has some play in the radial direction, the advancing / retreating block 42 is moved relative to the rotary shaft of the rotary table 38. It is possible to move it back and forth accurately in a coaxial manner. As a result, the material valve A positioned coaxially with the rotary shaft of the rotary table 38 by the valve mounting positioning means 33 can be reliably pressed and held without deviating the positional accuracy.

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 25 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, the powder supply device 26 is driven to supply a constant weight of welding material to the welding torch 25, and a high current is applied by the electrode 25d while the welding material is being jetted to melt the welding material. Eject toward the valve head of the valve A.

Here, the welding torch 25 side is set to a high voltage, and the material valve A side is grounded so that current flows from the welding torch 25 side toward the material valve A side. The weld material melted by the above is sprayed toward the valve head of the material valve A, and good overlay welding can be performed. In this embodiment, since the grounding mechanism 48 is provided, the above-described current flow can be generated, and good overlay welding can be performed. In the present embodiment, the base metal block 4
After the electric current from 5 flows into the cooling pipe 47, the cooling pipe 47
Flows from the contactor 48b of the grounding mechanism 48, which is in contact with, to the ground side through the terminal 48e. At this time, unlike the prior art, since the current flows directly to the contactor 48b without passing through the bearing 46, the conventional art may cause the bearing to be melted and damaged due to the spark generated when flowing through the bearing, and the rotary base 38 can be smoothly moved in a short period of time. However, in the present embodiment, stable rotation is assured for a long period of time. Therefore, the maintenance frequency is significantly reduced.

Further, when overlay welding is performed in the circumferential direction of the valve head of the material valve A, the iron component of the material valve A is melted out to the welded material at the rising portion and a large amount of iron component is present at the rising portion. Then, a phenomenon such as so-called dilution that causes a decrease in hardness occurs. In order to reduce this phenomenon, the photoelectric sensor 44c and the slit 44 are used in this embodiment.
The rotation angle of the turntable 38 is detected using the disc 44d having f, and as shown in FIG. 8, the rising portion (usually 1/8 of the circumference) where dilution easily occurs (points a to b) The current supplied to the welding torch 25 is gradually increased at the rising portion of the welding torch 25, and the buildup welding thickness is controlled so as to gradually increase from the point a to the point b as shown by the two-dot chain line in the figure. , 1 /
The control is performed so that a predetermined current is obtained when eight rounds (point b) have passed. Then, when one round (point a to point e to point a) is performed while detecting the rotation angle, the thickness of the overlay welding is thin at points a to b, and therefore, while further detecting the rotation angle, 1
The overlay welding is performed while gradually decreasing the current by / 8 turns, whereby a uniform overlay welding portion is formed over the entire circumference.

Further, 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.

During this overlay welding, cooling water is supplied to the cooling pipe 47.
Is supplied to the inner tube 47a of the base metal block 45a, and is discharged from the tip of the inner tube 47a arranged in the columnar portion 45b of the base metal block 45 to be returned to the outer tube 47b. In this way, the base metal block 45, particularly the columnar portion 45c, is cooled by the cooling water. As a result, the cylindrical portion 4 of the base metal block 45 is heated by the heat during welding.
The temperature of 5c is prevented from becoming high.

Here, a columnar portion 45c is formed at the upper end portion of the base metal block 45, and the diameter of the columnar portion 45c is made slightly larger than the diameter of the valve head of the material valve with which it abuts. Therefore, the mass of the base metal block 45 near the portion where the valve head abuts can be made appropriate, and it is possible to suppress overcooling of the valve head, particularly the peripheral portion of the valve head. As a result, welding defects caused by supercooling can be reduced. Also,
Since the diameter is slightly larger than the diameter of the valve head, it is possible to prevent the base metal block from reaching a high temperature.

Further, the cylinder portion 4 of the base metal block 45.
Since the upper surface of 5c is flat, when the material valve A is held in contact with the upper surface of the base metal block 45, the peripheral portion of the valve head is released without coming into contact with the base metal block 45. Therefore, the peripheral portion of the valve head does not come into contact with the base metal block 45, and it is possible to suppress uneven cooling of the valve head, and it is possible to reduce the occurrence of build-up welding failure due to this.

On the other hand, while the overlay welding is being performed by the welding torch 25, 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 sandwiched by 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 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 to be supplied next while the material valve A is held by the material valve holding means 30 and the overlay welding is being performed by the welding torch 25. 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.

[0055]

As described above, according to the overlay welding apparatus of the present invention, a welding torch for overlay welding a valve head of a material valve to be overlay welded, and a material valve to the welding torch. And a material valve holding means for holding the material valve obliquely so that the valve heads of the material valve face each other and rotating the material valve about an axis. The material valve holding means is a rotary table with which the end surface of the material valve on the valve head side abuts. Means and valve attaching / detaching means which is provided obliquely above the rotary table means and presses the valve stem of the material valve from above to detachably hold the material valve between the rotary table means and the rotary table means. The valve attaching / detaching means is a substantially columnar advancing / retreating block that is arranged coaxially with the rotary table means and has a groove formed in the center for inserting the valve stem. An advancing / retreating drive means for advancing / retreating the advancing / retreating block coaxially with the rotary table means; and a cylinder fixed to the fixed side of the advancing / retreating drive means on a fixed side and having the advancing / retreating block inserted in a substantially sliding contact state in a hollow portion thereof As a result, the powdery welding material injected from the welding torch can be prevented from entering the sliding part of the advancing / retreating drive means, and the galling of the sliding part can be prevented in advance. Even if there is some play in the sliding portion of the means in the direction intersecting with the advancing / retracting direction, the material valve positioned coaxially with the rotary shaft of the rotary table means is securely pressed and held without deviating its positional accuracy. be able to.

[Brief description of drawings]

FIG. 1 is a front view showing a build-up welding apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing the overlay welding device of FIG.

FIG. 3 is a view showing a welding torch used in the overlay welding apparatus of FIG. 1.

4 is a cross-sectional view showing a material valve holding means in FIG.

5 is an outline view seen from the direction a in FIG.

6 is a cross-sectional view taken along the line ROLL in FIG.

7 is a cross-sectional view showing a valve attaching / detaching means in FIG.

FIG. 8 is a diagram showing an operating state of the overlay welding device of FIG. 1.

9 is a partial cross-sectional view showing a valve manufactured by the overlay welding apparatus of FIG.

[Explanation of symbols]

 1 Valve 2 Valve Head 3 Overlay Welding Part 25 Welding Torch 30 Material Valve Holding Means 31 Rotating Table Means 32 Valve Attachment / Detachment Means 41 Grooves 42 Advance / Retract Blocks 43 Advance / Retract Drive Means 43a Frame (Fixed Side of Advance / Retract Drive Means) 43b Cylinder 45 Base Metal Block A material valve

Claims (1)

[Claims] 1. A build-up welding apparatus for build-up welding dissimilar materials to a valve head of a valve for an intake valve or an exhaust valve of an internal combustion engine, the valve head of a material valve to which build-up welding is applied. A material tongue for overlay welding; and a material valve holding means for holding the material valve diagonally so that the valve head of the material valve faces the welding torch and rotating the material valve about an axis. Is between the rotary table means with which the end face of the material valve on the valve head side abuts, and the valve stem of the material valve that is provided at a distance in an obliquely upward direction of the rotary table means from above to press the rotary table means. And a valve attaching / detaching means for detachably holding the material valve, wherein the valve attaching / detaching means is arranged coaxially with the rotary table means and has a valve stem at the center. A substantially columnar advancing / retreating block having a groove formed therein, an advancing / retreating drive means for advancing / retreating the advancing / retreating block coaxially with the rotary table means, and a fixed side of the advancing / retreating drive means fixed in the hollow portion thereof. A build-up welding apparatus, comprising: a cylinder into which the advancing / retreating block is inserted in a substantially sliding contact state.