JP2000061692A - Tack welding jig for boom of triangular section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily effect the assembly and the tack welding of a boom of triangular section with excellent accuracy. SOLUTION: Length setting means 30a, 30b on which insertion angle setting means 40a, 40b are mounted on an oscillating manner are arranged on an upper surface of a main bed 21 slidably in the longitudinal direction of the boom. Insertion means 50a, 50b to which a top bracket 10 and a foot bracket 12 are positioned and fixed are slidably attached to the insertion angle setting means 40a, 40b. A center bracket positioning means 70 to position and fix a center bracket 2 is installed on an approximately center part of the main bed 21, and a tube positioning means 90 to position a top tube 4 and a foot tube 5 is provided on the center bracket position means 70 and the insertion angle setting means 40a, 40b. After each member is positioned, the insertion means 50a, 50b are moved to the center bracket 2 side, and each member is simultaneously inserted and assembled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tack welding jig used for assembling and tack welding a boom of a hydraulic excavator, and more particularly to a tack welding jig for a boom having a triangular cross section.

[0002]

2. Description of the Related Art Conventionally, a boom used for a working machine of a hydraulic excavator (so-called hydraulic excavator) normally has a chevron shape in a side view as shown in FIG. A cast steel bracket 151, 15 having a member 155 and having pin holes for connection with a vehicle body or an arm at a base end portion and a tip end portion of a tubular member (hereinafter referred to as a tube) 155.
2 is welded. Further, a fan-shaped boom cylinder bracket 153 having a boom cylinder connecting pin hole is welded to a substantially central lower portion of the tube 155, and an arm cylinder bracket 154 having an arm cylinder connecting pin hole is provided on an upper surface near the tip of the central portion. It is welded.

Conventionally, the boom tube 155 has a box-shaped structure having a rectangular cross section or a round pipe structure. Then, brackets 151 and 152 are provided on both end surfaces of the tube 155 having a box structure or a pipe structure, respectively.
Abutting against and welding the boom cylinder bracket 15
3 and the arm cylinder bracket 154 are abutted and welded to the lower surface and the upper surface of the tube 155, respectively, and their sectional shapes are simple, so that they can be assembled relatively easily and the welding accuracy is also good.

[0004]

On the other hand, in order to improve the fuel efficiency of the engine and the turning performance behind the vehicle, it is necessary to reduce the weight of the boom and the arm (which is swingably connected to the tip of the boom). Is strongly requested. That is, since the boom and arm using the conventional tube of the above box structure are attached to the front end of the vehicle body and have a very large weight,
In order to balance with this weight, the counterweight is arranged as rearward of the vehicle body as possible. As a result, there is a problem that the entire vehicle becomes heavy and fuel consumption is reduced, or the counterweight protrudes rearward to increase the turning radius and lower the rearward turning performance.

As a method for solving this problem, studies have been made on a boom or arm using a tube having a triangular cross section, which has a rigidity substantially equal to that of a box-shaped tube, but can reduce the weight of the boom and arm. . This triangular cross-section tube is formed, for example, by welding the ends of one or more steel plates (one steel plate in the figure) bent into a predetermined shape with a predetermined radius of curvature, as shown in FIG. It has a triangular cross section. And, assembling such a triangular cross section boom,
For temporary attachment, it is necessary to position the triangular cross-section tube and each bracket, etc., insert the other end into one of the inner holes, and weld the outer periphery of the end.

However, since the bent portions R1, R2 and R3 of the triangular cross-section tube are formed by bending, the accuracy of the triangular cross-section shape greatly varies as compared with the conventional box-shaped or round-shaped structure, and Since the members to be welded such as the triangular cross-section tubes and the brackets are heavy objects, it is difficult to handle each member. Therefore, the positioning work and the insertion work of the end of each member are very difficult, and there is a problem that a large number of assembling and tack welding processes are required.

Focusing on the above problems, the present invention facilitates positioning work and insertion work of each welding target member easily, in a short time, and accurately when manufacturing a boom having a tube shape with a triangular cross section. It is an object of the present invention to provide a temporary welding jig for a boom having a triangular cross section.

[0008]

In order to achieve the above object, in the first invention of the tack welding jig for a boom having a triangular cross section according to the present invention, a boom cylinder connecting pin hole is provided. However, the fan-shaped center bracket in a side view, the top tube and the foot tube having a triangular cross-section that are welded by inserting one end into both front and rear ends of the center bracket, and the other end of the top tube and the foot tube Triangular cross section consisting of a top bracket and a foot bracket, each of which has a connecting pin hole and is welded by being inserted into a portion, and an arm cylinder bracket, which is welded at a predetermined position on the upper surface of the top tube, and forms a chevron in a side view. In a tack welding jig for a boom with a triangular cross section that assembles and tacks the boom, attach the top tube to the center bracket and Tube positioning means for positioning the foot tube with respect to the center bracket and the foot bracket, and positioning and fixing the boom cylinder connecting pin hole to fix the top tube of the center bracket. It has a center bracket positioning means for positioning with respect to the tube and the foot tube, and a positioning protrusion for abutting and positioning on the longitudinal end of the pin boss portion of the arm cylinder bracket, and a pair of left and right on the upper surface of the top tube. Arm cylinder bracket positioning means for setting the left-right center position of the arm cylinder bracket, and the top bracket and foot bracket are directed toward the center bracket side in accordance with the inclinations of the top tube and foot tube, respectively. Promotion and has a structure in which each bracket includes an insertion means for inserting the corresponding tube at the same time.

According to the above construction, firstly, since the tube positioning means for positioning the tube with respect to each bracket is provided, the insertion position of the tube with respect to the center bracket, the top bracket and the foot bracket can be accurately set. Therefore, since the insertion is smoothly performed, the time required for the insertion work is short and the assembling workability is improved. Secondly, since the center bracket positioning means based on the boom cylinder connecting pin hole is provided, the position of the center bracket can be accurately set and fixed. Since the insertion is performed smoothly, the insertion work time is shortened and the assembly workability is improved. Third
Further, since the arm cylinder bracket positioning means for positioning the pin boss portion by contacting the positioning protrusion is provided, the longitudinal position of the arm cylinder bracket can be easily and accurately set, and the assembling workability is improved.
Fourthly, since the top bracket and the foot bracket are provided with insertion means for propelling the top bracket and the foot bracket respectively toward the center bracket through the top tube and the foot tube and according to the respective inclination angles of the top tube and the foot tube, Each of these brackets and each tube are simultaneously and accurately inserted. Therefore, the assembly at the time of tack welding can be easily performed in a short time.

A second aspect of the present invention is the temporary welding jig for a boom having a triangular cross section according to the first aspect, wherein the tube positioning means uses a U-shaped or V-shaped guide portion having a wide upper opening width to form the top tube or foot tube. A tube bracket for supporting the center bracket positioning means,
The boom cylinder connecting pin hole has a positioning pin that is inserted by a predetermined amount from the left-right direction for positioning, and has a positioning pin that is clamped and fixed from the left-right direction.
Further, it has a centering tool for centering in the left-right direction with the top tube sandwiched, the insertion means is slidable in the longitudinal direction of the boom having a triangular cross section, and is inserted in the connecting pin hole of the top bracket from the left-right direction. A positioning pin for fixed amount insertion and positioning, and a top bracket positioning base having a bracket fixing means for fixing the top bracket, and a slidable body in a longitudinal direction of the boom having a triangular cross section, and a left and right direction in a connecting pin hole of the foot bracket. A positioning pin for inserting and positioning a predetermined amount, and a foot bracket positioning base having bracket fixing means for fixing the foot bracket,
The top bracket positioning base and the foot bracket positioning base are each provided with an insertion hydraulic cylinder that slides.

According to the above construction, firstly, since the tube receiving member of the tube positioning means is provided with the U-shaped or V-shaped guide portion having a wide upper surface opening and an inclined side wall, the tube is suspended from the upper portion. It is easy to insert when setting it in the tube receiver, and the set position is always stably positioned at a predetermined position. Therefore, the assembling workability is improved. Secondly, since the center bracket positioning means inserts a predetermined amount of the positioning pin into the boom cylinder connecting pin hole to position and fix it, the position of the center bracket in the left-right direction and the inclination direction with respect to the longitudinal direction can be accurately measured. And it can be easily set. This allows each tube to be inserted smoothly. Third
In addition, since the arm cylinder bracket positioning means is provided with the top tube centering tool integrally formed with the positioning protrusion, the centering tool allows the arm cylinder bracket to move in the left-right direction with respect to the longitudinal centerline of the top tube. Positioning becomes possible, and by bringing the arm cylinder bracket into contact with the positioning protrusion integrally formed with the arm cylinder bracket, the arm cylinder bracket can be welded to the correct position even at the bent portion of the upper portion of the triangular cross-section tube. Therefore, variations in the dimensional accuracy of the boom can be suppressed. Fourthly, the insertion means positions and fixes the top bracket and the foot bracket with the positioning pins with reference to the connecting pin holes of the top bracket and the foot bracket, respectively. The tilt direction with respect to the direction can be accurately positioned. This allows for smooth insertion. Further, the top bracket positioning base and the foot bracket positioning base are moved by the hydraulic cylinders, and thereby each bracket and each triangular cross-section tube are inserted, so that the insertion work can be performed easily.

According to a third aspect of the present invention, in the temporary welding jig for a three-sectioned boom of the first aspect, the lengths of the top bracket and the foot bracket in the longitudinal direction are set according to the length of the three-sided boom. Setting means, insertion angle setting means for setting the insertion angles of the top bracket and foot bracket according to the inclination of the top tube and foot tube, respectively, and positioning of the center bracket positioning means for positioning the boom cylinder connecting pin hole Positioning pin setting means for setting the pin position according to the type of the triangular cross section boom, and arm cylinder bracket setting means for setting the position of the arm cylinder bracket according to the type of the triangular cross section boom. It has a structure.

According to the above construction, firstly, since the length setting means for setting the longitudinal position of the top bracket and the foot bracket according to the boom length different according to the model is provided, one temporary mounting The welding jig can assemble booms of different lengths and perform tack welding. Second, since the insertion angle setting means that can set the insertion angle of each bracket according to the inclination of the tube is provided,
When performing tack welding of booms having different angles of inclination in a side view, the insertion angle can be set according to the angle of inclination. Thirdly, since the positioning pin setting means of the center bracket positioning means is provided, when the booms having different boom cylinder connecting pin positions of the center bracket are tack-welded, the positioning pin position is adjusted to the boom cylinder connecting pin position. Can be set. Fourth,
Since the arm cylinder bracket setting means is provided, the position of the arm cylinder bracket can be set even for booms having different arm cylinder bracket positions. Therefore, a plurality of booms can be assembled and tack welded using one tack welding jig, which is economical.

According to a fourth aspect of the present invention, there is provided a temporary welding jig for a boom having a triangular cross section according to the third aspect, wherein the length setting means is mounted on the upper surface of the main bed so as to be movable in the longitudinal direction of the boom. A first support base and a second support base that respectively support the foot bracket, and a first support base and a second support base.
A length setting hydraulic cylinder for moving the supports in the boom longitudinal direction, and the insertion angle setting means sets the first insertion table and the second support table so that a predetermined insertion angle can be set.
A top bracket positioning base and a foot bracket positioning base that are swingably attached to the support base and that position and fix the top bracket and foot bracket, respectively, are mounted slidably in the longitudinal direction of the triangular cross section boom. It has a first rocking table and a second rocking table, and an angle setting hydraulic cylinder for rocking the first rocking table and the second rocking table, and the positioning pin setting means determines the height position of the positioning pin. The arm cylinder bracket setting means has a height adjustment hydraulic cylinder for vertically moving the positioning protrusion, and a front-back adjustment hydraulic cylinder for moving the front-back direction.

According to the above structure, first, the length setting means is provided with the first support base and the second support base capable of setting the longitudinal positions of the top bracket and the foot bracket by the length setting hydraulic cylinder. It can be easily set to a predetermined position according to booms of different lengths, improving workability. Secondly, since the insertion angle setting means is provided with the first rocking table and the second rocking table capable of setting the insertion angles of the top bracket and the foot bracket by the angle setting hydraulic cylinder, it is possible to match the booms with different insertion angles. The insertion angle can be easily set, and workability is improved. Thirdly, since the positioning pin setting means of the center bracket positioning means is provided with the lifting hydraulic cylinder, it is possible to set the height position of the positioning pin according to different booms.
Workability is improved. Fourthly, since the arm cylinder bracket setting means is provided with the height adjusting hydraulic cylinder and the front-rear adjusting hydraulic cylinder, the position of the positioning protrusion can be easily adjusted according to different booms, and workability is improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a tack welding jig for a boom having a triangular cross section according to the present invention will be described below with reference to FIGS.
Will be described in detail. FIG. 1 is a side view of a boom 1 having a triangular cross section according to the present invention. Boom cylinder connecting pin hole 3
A- is provided on both ends of the center bracket 2 having
One ends of a tube-shaped top tube 4 and a foot tube 5 having a substantially triangular cross section as shown in the cross section A and the cross section BB are inserted, and the outer peripheries of the ends are welded. Further, the other ends of the top tube 4 and the foot tube 5 are inserted and welded to the respective ends of the top bracket 10 having the connecting pin hole 11a and the foot bracket 12 having the connecting pin hole 11b. Further, an arm cylinder bracket 16 is welded to the upper surface of the top tube 4.

FIG. 2 is a diagram for explaining a method of inserting each triangular cross-section tube and each bracket such as the center bracket 2, the top bracket 10 and the foot bracket 12, in which the top tube 4 and the top bracket 10 are shown.
Represents the state before insertion. In the figure, a stepped portion 13 is provided on the outer periphery of the end portion of the top bracket 10, and an insertion hole 14 is provided on the inner peripheral portion. A backup ring 6 is welded to the inner peripheral portion of the end portion of the top tube 4. Top tube 4 when assembling
The backup ring 6 is inserted into the insertion hole 14 of the top bracket 10, and the end surface 7 of the top tube 4 and the rear end surface 15 of the top bracket 10 are brought into contact with each other. As a result, the stepped portion 13 forms a weld groove and the root gap is guaranteed. After performing tack welding in this state, main welding is performed. The other tubes and the insertion portion of the bracket have the same structure.

FIG. 3 is a side view showing an outline of the tack welding jig 20. The first insertion angle setting means 4 is provided near both ends of the upper surface of the main bed 21 installed on the ground in the longitudinal direction.
The first length setting means 30a provided with 0a and the second length setting means 30b provided with the second insertion angle setting means 40b are mounted slidably in the longitudinal direction. A first insertion means 50a for moving the top bracket 10 in the insertion direction is mounted on the first insertion angle setting means 40a, and a foot bracket 12 for moving the foot bracket 12 in the insertion direction is mounted on the second insertion angle setting means 40b. The 2 insertion means 50b is mounted. A center bracket 2 is provided at the center of the main bed 21.
Center bracket positioning means 7 for positioning and fixing
0 is placed. Center bracket positioning means 7
The 0 and the first insertion angle setting means 40a and the second insertion angle setting means 40b are provided with tube positioning means 90 for positioning the top tube 4 and the foot tube 5 in the left-right direction with respect to the longitudinal direction. In front of the center bracket positioning means 70, an arm cylinder bracket positioning means 100 for positioning the arm cylinder bracket 16 with respect to the top tube 4 is provided.
1 is placed on. The temporary welding jig for this triangular cross section boom is designed to support multiple booms of different sizes depending on the model of the hydraulic excavator. The thin two-dot chain line shows the large boom 1a. The small boom 1b is indicated by a thin broken line.

Each means will be described in detail below. 4 is a partial side sectional view of the first length setting means 30a, the first insertion angle setting means 40a and the first insertion means 50a, and FIG. 5 is a plan view. First, the first length setting means 3
0a will be described. A pair of left and right first guide rails 2 longitudinally provided on one end of the upper surface of the main bed 21.
A first support base 31a is slidably engaged with 2,2. The main bed 21 and the first support base 31a are connected by a length setting hydraulic cylinder 32, and the first support base 31a is extended along the first guide rail 22 by extending and contracting the length setting hydraulic cylinder 32. Move to. The stroke is at least the top bracket 1 of the large boom 1a.
The difference between the connecting pin position of 0 and the connecting pin position of the small boom 1b is L1 or more, and the position can be set for any boom. The means for moving the first support base 31a in the longitudinal direction in the first length setting means 30a is not limited to the length setting hydraulic cylinder 32, and may be, for example, a combination of a motor and a ball screw.

Next, the first insertion angle setting means 40a will be described. In the pair of brackets 33, 33 fixed to the first support base 31a, the pair of brackets 42, 42 fixed to one end of the first swing base 41a are attached to the pins 34, 34.
It is attached so that it can swing freely. One end of the angle setting hydraulic cylinder 43 is attached to the upper surface of the first support base 31a, and the other end of the angle setting hydraulic cylinder 43 and the other end of the first rocking base 41a are connected by a link 44. Has been done. The other end of the angle setting hydraulic cylinder 43 has the first support base 3
It engages with a guide 45 fixedly provided on the upper surface of 1a along the longitudinal direction. When the angle setting hydraulic cylinder 43 is expanded and contracted, the connecting portion between the link 44 and the angle setting hydraulic cylinder 43 moves along the guide 45, and the action of the link 44 causes the first swing base 41a to swing about the pins 3 and 34. Move,
The elevation angle α of the first swing table 41a is changed. The elevation angle α is the inclination angle of the large boom 1a (that is, the top bracket 10
Angle .beta.1 of the small boom 1b and the inclination angle .beta.2 of the small boom 1b (similarly, the angle of insertion .beta.2), and the insertion angle can be set for any boom.

Next, the first inserting means 50a will be described. A pair of left and right guide rails 51, 51 is fixed in the longitudinal direction on the upper surface of the first swing base 41a, and the top bracket positioning is slidable in the longitudinal direction along the pair of left and right guide rails 51, 51. A table 52a is provided. The first swing base 41a and the top bracket positioning base 52a are connected by an insertion hydraulic cylinder 53. The top bracket positioning base 52a includes the top bracket 1
A pair of left and right positioning pins 54, 54 for positioning 0
And bracket fixing means 60 for fixing the top bracket 10 are provided. Each positioning pin 54 is slidably inserted in each cylinder 56 attached to a pair of left and right brackets 55, 55 fixed to the top bracket positioning base 52a, and the inside of the cylinder 56 is moved by a hydraulic cylinder 57. Slide. The bracket fixing means 60 is
A clamp 62 rotatably attached to a bracket 61 fixed to the rear portion of the top bracket positioning base 52a.
And a clamp hydraulic cylinder 63 connected between the clamp 62 and the bracket 61, and a bracket positioning tool 64 arranged at the tip of the top bracket positioning base 52a at the center in the left-right direction. When positioning and fixing the top bracket 10, the rear end portion of the top bracket 10 is mounted on the upper surface of the positioning tool 64, the positioning pin 54 is pushed out by the hydraulic cylinder 57, and the tip end portion of the positioning pin 54 is moved to the top bracket 10. A predetermined amount is inserted into the connecting pin hole 11a for positioning. Next, the clamp hydraulic cylinder 63 is extended to press and fix the top bracket 10 at the tip of the clamp 62. Thereafter, when the insertion hydraulic cylinder 53 is extended, the top bracket positioning base 52a moves along the guide rail 51 along with the top bracket 10 in the right direction in the drawing.

FIG. 6 is a partial side sectional view of the second length setting means 30b, the second insertion angle setting means 40b and the second insertion means 50b. The constitution is the above-mentioned first length setting means 30a,
The plan view is omitted because it is the same as the first insertion angle setting means 40a and the first insertion means 50a. The details are omitted, and the outline will be described. A second support base 31b of a second length setting means 30b is slidably mounted on the other end of the upper surface of the main bed 21, and a second swing of the second insertion angle setting means 40b is mounted on the second support base 31b. A moving base 41b is swingably attached. The foot bracket positioning base 52b of the second insertion means 50b is mounted on the second swing base 41b so as to be slidable in the longitudinal direction. A positioning pin 54, a clamp 62 and a bracket positioning tool 64 are provided on the foot bracket positioning base 52b to position and fix the foot bracket 12 and slide it in the insertion direction. The stroke of the second length setting means 30b is at least the difference L2 between the positions of the connecting pin holes of the foot brackets of the large boom 1a and the small boom 1b. Further, the angle change of the second insertion angle setting means 40b can be set to the inclination angles γ1 and γ2 of the large boom 1a and the small boom 1b, and the insertion angle can be set for any boom.

Next, the center bracket positioning means 70
Will be described. 7 and 8 are a side view and a plan view of the center bracket positioning means 70, respectively.
A first jack 72 and a second jack 73 that support the center bracket 2 are attached to the upper surface of a pedestal 71 that is disposed in the substantially central portion of the main bed 21. A pair of positioning pin setting means 80, 80 is arranged on both left and right sides of the gantry 71. A pin support base 83 that is moved up and down by a lifting hydraulic cylinder 82 is provided on the upper portion of the support column 81 attached on the main bed 21, and constitutes positioning pin setting means 80. A cylinder 74 is attached to an upper portion of the pin support base 83, and a positioning pin 75 is slidably provided in the cylinder 74. The positioning pin 75 is slidable in the cylinder 74 by a hydraulic cylinder 76. Has become. When positioning the center bracket 2, the center bracket 2 is mounted on the upper surfaces of the first jack 72 and the second jack 73, the hydraulic cylinder 76 is extended, and the positioning pins 75 are provided from the left and right to the boom cylinder connecting pin hole of the center bracket 2. It is fixed by inserting a predetermined amount into 3 and positioning. The height adjustment of the center bracket 2 and the inclination adjustment in the longitudinal direction are performed by adjusting the heights of the first jack 72 and the second jack 73. By expanding and contracting the lifting hydraulic cylinder 82, the height position of the positioning pin 75 is adjusted to the large boom 1
a or small boom 1b.

Next, the tube positioning means 90 will be described. A tube positioning means 90 is provided at each of the front and rear ends of the gantry 71 shown in FIG. 7, the rear end of the first swing base 41a shown in FIG. 4, and the rear end of the second swing base 41b shown in FIG.
Are provided for positioning the top tube 4 and the foot tube 5 in the left-right direction with respect to the longitudinal direction. Each tube positioning means 90
Is disposed near both ends of each tube, that is, at a position as close as possible to the bracket to be inserted. Each tube positioning means 90 is a tube receiver 91 of the first embodiment.
And a tube positioning tool 95. FIG. 9 is a view on arrow C of FIG. 7. The tube receiver 91 is provided with a U-shaped guide portion 92 having an opening at the top, and the upper surface opening width W
Is wide, and the side surface 93 of the guide portion is open upward and inclined.
The tube positioning device 9 is provided at the center of the tube receiving device 91.
5 is provided to determine the height position of the tube. A pair of blocks 94, 94 that hold down the inclined portion of the lower side surface of the top tube 4 or the foot tube 5 having a triangular cross-sectional shape are slidably provided in the left and right directions inside the guide portion 92 of the tube receiver 91. , Is designed to fix the tube.

FIG. 10 shows a state in which the tube is suspended and set in the tube receiving member 91. Since the guide portion 92 is open at the upper side, the top tube 4 or the foot tube 5 is slightly displaced, or Even if it is inclined, it is guided by the side surface 93 of the guide portion and settles near the center of the substantially U-shaped guide portion 92. Therefore, setting is easy.

Next, the arm cylinder bracket positioning means 100 will be described. 11 is a side view of the arm cylinder bracket positioning means 100, FIG. 12 is a front view, and FIG. 13 is a plan view. An arm cylinder bracket positioning means 100 is arranged on the top tube 4 side of the pedestal 71 placed on the main bed 21. On the upper surface of the bed 101 placed on the main bed 21, a positioning device 110 is installed on the guide rail 102 in the left-right direction.
And is slidably arranged. Positioning device 1
Position setting means 120 is provided on the main body 111 of the apparatus 10. A column 121 is provided at one side end of the main body 111, and a guide 122 attached to the column 121 has a moving column 12 that moves up and down by a height adjusting hydraulic cylinder 123.
4 is slidably engaged. A plate 125 is horizontally fixed to the upper end of the moving support column 124.
A positioning support stand 127, which is movable in the front-rear direction by a front-rear adjustment hydraulic cylinder 126 shown in FIG.

One end of the positioning arm 112 is attached to the positioning support base 127 by a pin 113 so as to be rotatable in the left-right direction as shown by a thin two-dot chain line in FIG. At the tip of the positioning arm 112, a pair of positioning protrusions 114, 114 are provided, which abut on the tip ends of the pair of arm cylinder brackets 16, 16 in the longitudinal direction of the pin bosses 17, 17 for positioning in the longitudinal direction. .
In addition, a positioning tool 115 that abuts on the inner surfaces of the pin bosses 17, 17 that face each other and positions in the left-right direction is integrated with the protrusion 113, and as shown by the thin double-dotted line in FIG.
It is attached so as to be rotatable in the front-rear direction. Positioning tool 11
Each of the left and right sides of 5 is provided with three protrusions 116 that come into contact with the surface of the pin boss 17. Also, the main body 11
1 is provided with a pair of centering tools 117, 117 for centering in the left-right direction by sandwiching the top tube 4 from the left and right. As shown in FIG. 12, the centering tools 117 and 117 are
The top boom 4 is driven by a drive device (not shown) (for example, one feed screw having a right-hand screw and a left-hand screw).
The center lines X-X are moved in the opposite directions by the same amount. Where the center line X-
X coincides with the center of the positioning tool 115 described above.

The procedure for setting the boom 1 having a triangular cross section on the temporary jig will be described below. 1) The positioning arm 112 of the arm cylinder bracket positioning means 100 is rotated as shown by the thin chain double-dashed line in FIG. 2) The first support base 31a of the first length setting means 30a and the second length setting means 3 according to the length of the boom to be temporarily attached.
The 0b second support base 31b is moved to a predetermined position by the length setting hydraulic cylinder 32 to set the length. 3) Next, the first rocking table 4 of the first insertion angle setting means 40a
1a and the second rocking base 4 of the second insertion angle setting means 40b
1b is adjusted to the inclination of the boom top tube 4 and the hood tube 5 by the angle setting hydraulic cylinder 43, and the insertion angle is set. 4) Next, the top bracket 10 is positioned on the top bracket positioning base 52a of the first inserting means 50a, and the foot bracket 12 is positioned on the foot bracket positioning base 52b of the second inserting means 50b, and the clamp 62 of the bracket fixing means 60 is positioned. Fix with. 5) Next, the top tube 4 and the foot tube 5 are suspended from above, placed on the tube receiver 91 of the tube positioning means 90, and positioned. 6) Next, the center bracket positioning means 70 positions and fixes the center bracket 2 at a predetermined position. 7) In addition, the insertion parts of the brackets and the tubes are set with a predetermined space. 8) Next, the first insertion means 50a and the second insertion means 50b
The insertion bracket hydraulic cylinder 53 moves the top bracket positioning base 52a and the foot bracket positioning base 52b toward the center bracket 2. First, the insertion portions of the top bracket 10 and the top tube 4, and the foot bracket 12 and the foot tube 5 are inserted, and their end surfaces abut. Next, the top bracket 10 and the top tube 4, and the foot bracket 12 and the foot tube 5 are integrally moved to the center bracket 2, respectively.
Also, the insertion part with the foot tube is inserted, and the end faces abut. In this state, each insertion part is temporarily attached. 9) Next, arm cylinder bracket positioning means 10
The zero centering tools 117 and 117 are moved to sandwich the top boom 4 for centering. At this time, one of the centering tools 1
When only 17 contacts one side of the top boom 4, the main body 111 is moved in the left-right direction to perform centering. After the centering of the top tube 4 is completed, as shown by the solid line in FIG. 12, the positioning arm 112 is rotated to position the positioning protrusion 114 and the positioning tool 115 directly above the top tube 4. Next, with the front ends of the pin bosses 17, 17 of the pair of arm cylinder brackets 16, 16 abutting on the positioning protrusions 114, 114, and the inner surface of the pin boss 17 abutting on both the left and right sides of the positioning tool 115. The cylinder brackets 16 and 16 are temporarily attached to the top tube 4.

FIG. 14 shows a tube receiver 9 of the second embodiment.
It is a front view of 1a. The tube receiver 91a is provided with a V-shaped guide portion 92a to further facilitate insertion of the tube from above.

The temporary welding jig described above is capable of assembling and temporarily mounting the large boom 1a and the small boom 1b with a single jig. As long as one kind of boom is assembled and temporarily attached, the length setting means 30a, 30 described above is used.
b, the insertion angle setting means 40a and 40b, the positioning pin setting means 80 of the center bracket positioning means 70, and the arm cylinder bracket setting means 120 are unnecessary.

[Brief description of drawings]

FIG. 1 is a side view of a boom having a triangular cross section.

[Fig. 2] Insertion method of each triangular cross-section tube and each bracket (example of insertion of top tube and top bracket)
FIG.

FIG. 3 is a side view showing an outline of a tack welding jig of the present invention.

FIG. 4 is a partial side sectional view of the first length setting means, the first insertion angle setting means and the first insertion means of the present invention.

FIG. 5 is a plan view of the first length setting means, the first insertion angle setting means, and the first insertion means of the present invention.

FIG. 6 is a partial side cross-sectional view of the second length setting means, the second insertion angle setting means, and the second insertion means of the present invention.

FIG. 7 is a side view of the center bracket positioning means of the present invention.

FIG. 8 is a plan view of the center bracket positioning means of the present invention.

FIG. 9 is a front view of the tube positioning means according to the first embodiment of the present invention (a view taken in the direction of arrow C in FIG. 7).

FIG. 10 is an explanatory diagram of setting a tube on the tube positioning means according to the first embodiment of the present invention.

FIG. 11 is a side view of the arm cylinder bracket positioning means of the present invention.

FIG. 12 is a front view of arm cylinder bracket positioning means of the present invention.

FIG. 13 is a plan view of arm cylinder bracket positioning means of the present invention.

FIG. 14 is a front view of the vip positioning means according to the second embodiment of the present invention.

FIG. 15 is a side view of a boom having a general boom shape.

FIG. 16 is a diagram illustrating a problem of the triangular cross-section tube according to the present invention.

[Explanation of symbols]

1 ... Triangular section boom, 2 ... Center bracket, 3 ... Boom cylinder connecting pin hole, 4 ... Top tube, 5 ... Foot tube, 10 ... Top bracket, 11a, 11b
... connecting pin hole, 12 ... foot bracket, 16 ... arm cylinder bracket, 17 ... pin boss, 20 ... temporary welding jig, 21 ... main bed, 30a ... first length setting means,
30b ... 2nd length setting means, 31a ... 1st support stand, 31
b ... Stand 2 support stand, 32 ... Length setting hydraulic cylinder, 40a
... first insertion angle setting means, 40b ... second insertion angle setting means, 41a ... first rocking table, 41b ... second rocking table, 43 ...
Angle setting hydraulic cylinder, 44 ... Link, 50a ... First inserting means, 50b ... Second inserting means, 52a ... Top bracket positioning base, 52b ... Foot bracket positioning base, 53 ... Inserting hydraulic cylinder, 54, 75 ... Positioning pin, 60 ... Bracket fixing means, 62 ... Clamp, 70
... center bracket positioning means, 80 ... positioning pin setting means, 82 ... lifting hydraulic cylinder, 90 ... tube positioning means, 91 ... tube receiver, 92 ... guide part, 1
00 ... Arm cylinder bracket positioning means, 110
... Positioning device, 114 ... Positioning protrusion, 115 ... Positioning tool, 117 ... Centering tool, 120 ... Arm cylinder bracket setting means, 123 ... Height adjusting hydraulic cylinder,
126 ... Front-rear adjustment hydraulic cylinder.

Claims (4)

[Claims] 1. A boom cylinder connecting pin hole (3) is provided,
A fan-shaped center bracket (2) in a side view, and a top tube (4) and a foot tube (5) with a triangular cross-section that are welded by inserting one end into both front and rear ends of the center bracket (2). And top tube (4) and foot tube
The top bracket (10) and the foot bracket (12), which have the connecting pin holes (11a, 11b), respectively, which are inserted into the other end of (5) and welded, and the top bracket (10) at the predetermined positions on the top tube (4). A temporary welding jig for a triangular cross section boom, comprising an arm cylinder bracket (16) to be welded and forming a chevron in side view, and performing temporary welding. Tube positioning means for positioning (4) with respect to the center bracket (2) and top bracket (10) and positioning the foot tube (5) with respect to the center bracket (2) and foot bracket (12). (90) and the boom cylinder connecting pin hole (3) are positioned and fixed so that the center bracket (2) is positioned with respect to the top tube (4) and the foot tube (5). Door positioning means (7
0) and a positioning protrusion (1) for positioning by abutting on the longitudinal end of the pin boss (17) of the arm cylinder bracket (16).
14) and the arm cylinder bracket positioning means (1) for setting the left and right center positions of the pair of left and right arm cylinder brackets (16, 16) on the upper surface of the top tube (4).
00) and the top bracket (10) and foot bracket (12) according to the inclinations of the top tube (4) and foot tube (5), and propel them toward the center bracket (2). And a inserting means (50a, 50b) for simultaneously inserting into a corresponding tube. 2. The temporary welding jig for a boom having a triangular cross section according to claim 1, wherein the tube positioning means (90) has a wide upper surface opening width U.
Top tube (4) with V-shaped or V-shaped guide (92)
Or tube receiver (91) that supports the foot tube (5)
The center bracket positioning means (70) inserts a predetermined amount into the boom cylinder connecting pin hole (3) from the left and right for positioning, and holds the positioning pin (75) for sandwiching and fixing from the left and right. Having, the arm cylinder bracket positioning means (100),
A centering tool (1) that is integrated with the positioning protrusion (114) and that centers the top tube (4) in the left-right direction.
17), the insertion means (50a, 50b) is slidable in the longitudinal direction of the boom (1) with a triangular cross section, and is inserted into the connecting pin hole (11a) of the top bracket (10) from the left and right directions. A top bracket positioning base (52a) having a positioning pin (54) for fixed amount insertion and positioning, and a bracket fixing means (60) for fixing the top bracket (10), and sliding in the longitudinal direction of the triangular cross section boom (1). The foot bracket (12) has a connecting pin hole (11
b) a foot bracket positioning base (52b) having a positioning pin (54) for inserting and positioning the foot bracket (12) in a right and left direction and a bracket fixing means (60) for fixing the foot bracket (12), and a top bracket positioning base (52b). 52a) and an insert hydraulic cylinder (53, 53) for sliding the foot bracket positioning base (52b) respectively, and a temporary welding jig for a triangular cross section boom. 3. The temporary welding jig for a boom having a triangular cross section according to claim 1, wherein the positions of the top bracket (10) and the foot bracket (12) in the longitudinal direction are set to the length of the boom having a triangular cross section (1). The length setting means (30a, 30b) and the insertion angles of the top bracket (10) and the foot bracket (12) according to the inclination of the top tube (4) and the foot tube (5), respectively. Insertion angle setting means to be set
(40a, 40b) and the positioning pin (75) of the center bracket positioning means (70) for positioning the boom cylinder connecting pin hole (3)
Positioning pin setting means (80) that can set the position of 3 to match the type of triangular section boom (1), and the position of the arm cylinder bracket (16) to the type of triangular section boom (1). 3. An arm cylinder bracket setting means (120) for setting together 3
Temporary welding jig for square cross section boom. 4. The temporary welding jig for a boom having a triangular cross section according to claim 3, wherein the length setting means (30a, 30b) is mounted on the upper surface of the main bed (21) so as to be movable in the longitudinal direction of the boom. And top bracket (10) and foot bracket
Setting the length to move the first support table (31a) and the second support table (31b) supporting the (12) respectively, and the first support table (31a) and the second support table (31b) in the boom longitudinal direction. The insertion angle setting means (40a, 40b) has a hydraulic cylinder (32), and the insertion angle setting means (40a, 40b) can set a predetermined insertion angle.
a) A top bracket positioning base (52a) and a foot bracket positioning base that are swingably attached to the second support base (31b) and position and fix the top bracket (10) and the foot bracket (12) respectively. 3 for (52b)
First mounted slidably in the longitudinal direction of the boom (1) with square cross section
An oscillating table (41a) and a second oscillating table (41b), and an angle setting hydraulic cylinder (43) for oscillating the first oscillating table (41a) and the second oscillating table (41b), The positioning pin setting means (80) has a lifting hydraulic cylinder (82) for setting the height position of the positioning pin (75), and the arm cylinder bracket setting means (120) includes the positioning protrusion (114). A temporary welding jig for a boom having a triangular cross section, which has a height adjusting hydraulic cylinder (123) for vertically moving the arm and a front-rear adjusting hydraulic cylinder (126) for moving the arm in the front-back direction.