JP5363276B2 - Sprocket segment manufacturing equipment - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a sprocket segment constituting a sprocket of a tracked vehicle including a construction machine such as a bulldozer and an agricultural vehicle.

  In recent years, sprockets used for undercarriage of construction machines such as bulldozers and hydraulic excavators, or tracked vehicles such as agricultural vehicles have been provided with a plurality of teeth on the outer periphery, and are formed as a unit when they are large. Difficult to do. Therefore, it forges in the unit of the sprocket segment divided | segmented into the circumferential direction, and one sprocket is comprised combining this.

Such sprocket segment forging methods include a method called vertical punching in which pressure molding is performed in a direction perpendicular to the tooth surface of the sprocket segment, and a method called horizontal punching in which pressure molding is performed in a direction parallel to the tooth surface. is there.
For example, in Patent Documents 1 and 2, in the forging of a 5-tooth sprocket segment by vertical punching, tooth portions at both ends are deformed in advance so as not to cause undercut, and after forging (usually after deburring ), A method for deforming the tooth portion that has been deformed into a desired shape using dedicated equipment, a mold or the like is disclosed.

However, the above conventional sprocket segment manufacturing method has the following problems.
That is, in the sprocket segment manufacturing method disclosed in the above publication, a high forming force is required to deform the tooth portion formed in consideration of the undercut. A press device is required.

  An object of the present invention is to produce a sprocket segment that can produce a sprocket segment of a desired shape at a low cost without installing a special equipment for deforming a tooth part or a high pressure capacity equipment. To provide an apparatus.

A sprocket segment manufacturing apparatus according to a first aspect of the present invention is a sprocket segment manufacturing apparatus that deforms a tooth portion that is forged and shaped into a desired shape in consideration of undercut, and includes a support portion, a press mechanism, And a rotating member. The support part supports the sprocket segment. The press mechanism pressurizes the sprocket segment supported by the support portion in a predetermined direction. Rotating member is disposed close to the tooth surface of the particular tooth portion of the sprocket segments supported at the support unit, when the sprocket segment by a press mechanism Ru pressurized, the tooth surfaces of the particular tooth portion of the sprocket segment On the other hand, the shape of the tooth portion is deformed by rotating in an arc shape while the tip portion abuts.

  Here, a sprocket segment including a tooth portion forged so as to include a portion deformed in advance so as not to cause undercut in consideration of a draft angle from the mold was supported by the support portion after forging. While applying pressure to the sprocket segment in a predetermined direction, rotate the tip of the rotating member against the tooth surface of the tooth to be deformed and rotate it to deform the tooth into the desired shape. Let

Here, the said rotation member is a member contact | abutted to the tooth surface of a sprocket segment, Comprising: A front-end | tip part moves toward a tooth tip from a tooth bottom by the press by a press mechanism, for example.
Thereby, the tooth | gear part deform | transformed beforehand so that an undercut may not occur can be easily changed into a desired shape with a small pressure by rotating the rotating member along the tooth surface. Therefore, a sprocket segment having a desired shape can be manufactured at a low cost without installing special equipment for deforming the tooth portion or equipment having high pressurization capacity.

A sprocket segment manufacturing apparatus according to a second aspect of the present invention is the sprocket segment manufacturing apparatus according to the first aspect of the present invention, wherein the press mechanism includes a pressing member that comes into contact with a flange portion opposite to the sprocket segment teeth. And a pressing mechanism that presses the pressing member.
Here, the press mechanism is configured to include a pressing member that contacts the flange portion side of the sprocket segment, and a pressing mechanism that presses the pressing member in a predetermined direction.
Here, the pressing mechanism includes a nitrogen gas cylinder, a hydraulic cylinder, and the like.
Thereby, the shape of the tooth | gear part deform | transformed previously so that an undercut may not occur can be changed into a desired shape by the simple structure which combined the said press mechanism and the rotation member.

  A sprocket segment manufacturing apparatus according to a third aspect of the present invention is the sprocket segment manufacturing apparatus according to the first or second aspect of the present invention, wherein the rotating member has a tip portion extending from the tooth bottom to the tooth tip at the tooth portion. Rotate to move.

Here, when the tooth portion of the sprocket segment is deformed, first, pressure is applied to the sprocket segment by the press mechanism in a state where the tip portion of the rotating member is in contact with the tooth bottom. And a tooth | gear part is deform | transformed into a desired shape by rotating toward the tooth tip, with the front-end | tip part of a rotation member contacting a tooth surface.
Thereby, about the sprocket segment forge-molded so that the tooth part deform | transformed so that an undercut may not be generated can be deform | transformed into a desired shape by a pressure smaller than before.

A sprocket segment manufacturing apparatus according to a fourth aspect of the present invention is the sprocket segment manufacturing apparatus according to any one of the first to third aspects of the present invention, wherein the turning radius R of the turning member is the tooth of the sprocket segment. It is set according to the size of r of the tooth surface connecting the tooth bottom to the tooth bottom .
Here, the turning radius R of the turning member is set based on the radius r of the tooth surface of the tooth portion of the sprocket segment.

Here, the turning radius R of the turning member means the distance from the turning shaft serving as the turning center to the tip portion that contacts the tooth surface. The radius r of the tooth surface of the tooth portion means the radius of the curved surface of the tooth surface that rotates while the tip of the rotating member comes into contact therewith.
Thus, the tooth member can be easily deformed into a desired shape simply by rotating the rotating member while contacting the tooth surface.

A sprocket segment manufacturing apparatus according to a fifth aspect of the present invention is the sprocket segment manufacturing apparatus according to any one of the first to fourth aspects of the present invention, wherein the tip part of the rotating member is deformed by the tooth part. There is further provided an urging member for urging to the opposite side to the rotation direction.
Here, the biasing member biases the tip of the rotating member in a direction opposite to the direction of rotation when the tooth portion is deformed.

Here, as the urging member, for example, a winding spring or the like can be used.
Thus, after the step of deforming the tooth portion is completed, the rotating member can be returned to the initial position by the urging force of the urging member. Therefore, it is not necessary to return the rotating member to the initial position every time the deformation process is completed, and the manufacturing process can be made more efficient.

A sprocket segment manufacturing apparatus according to a sixth aspect of the present invention is the sprocket segment manufacturing apparatus according to any one of the first to fifth aspects of the present invention, wherein a plurality of rotating members are provided.
Here, for example, a plurality of rotating members are provided so as to come into contact with the tooth portions provided at both ends of the sprocket segment.
Here, it is desirable that the plurality of rotating members be provided so as to come into contact with, for example, tooth portions provided at both ends of the sprocket segment.
As a result, even when there are a plurality of teeth that are deformed so as not to cause an undercut in the sprocket segment, the rotating members are brought into contact with each tooth and rotated, thereby making it possible to perform a single process. A plurality of teeth can be deformed into a desired shape.

  According to the sprocket segment manufacturing apparatus according to the present invention, a sprocket segment having a desired shape can be manufactured at a low cost without installing special equipment for deforming teeth or equipment having high pressurization capacity. Can do.

The perspective view which shows the structure of the bulldozer carrying the sprocket using the sprocket segment which concerns on one Embodiment of this invention. The perspective view which shows the structure of the sprocket mounted in the bulldozer of FIG. (A)-(c) is the whole perspective view, front view, and side view which show the structure of the sprocket segment which comprises the sprocket of FIG. The perspective view which shows the structure after the forge molding of the sprocket segment of FIG. The side view which shows the structure of the sprocket segment after the forge molding of FIG. The schematic diagram which shows the structure of the metal mold | die which forge-molds the sprocket segment of FIG. The perspective view which shows the 1st metal mold | die arrange | positioned above the metal mold | die of FIG. The perspective view which shows the 2nd metal mold | die arrange | positioned under the metal mold | die of FIG. Explanatory drawing which shows the flow of the manufacturing process of the sprocket segment of FIG. Explanatory drawing which shows the flow of the manufacturing process of the sprocket segment of FIG. The flowchart which shows the flow of the manufacturing process of the sprocket segment of FIG. (A), (b) is a front view which shows the structure of the bending apparatus which deform | transforms the tooth | gear part deform | transformed previously so that the undercut in the sprocket segment concerning one Embodiment of this invention may not arise. Explanatory drawing which shows a part of bending process by the bending apparatus of FIG. (A)-(c) is explanatory drawing which shows the flow of the bending process by the bending apparatus of FIG. The elements on larger scale which show the motion of the rotation member in the bending process of FIG. (A), (b) is explanatory drawing which shows the flow of the bending process by the bending apparatus which concerns on other embodiment of this invention. Explanatory drawing which shows the flow of the manufacturing process of the three-tooth sprocket segment which concerns on other embodiment of this invention.

A bending apparatus 20 (sprocket segment manufacturing apparatus) according to an embodiment of the present invention and a bulldozer 1 equipped with a sprocket segment 10 manufactured thereby will be described with reference to FIGS. is there.
[Configuration of Bulldozer 1]
The bulldozer 1 according to the present embodiment is a construction machine that performs leveling work on rough terrain, and mainly includes a cab 2, a body frame 3, a blade 4, a ripper (work machine) 5, and a traveling as shown in FIG. A device 7 is provided.

The cab 2 is provided with an operator seat (driver's seat) for a driver (operator) to sit on, a lever, a pedal, and instruments for various operations.
A working mechanism such as a blade 4 and a ripper 5 and a traveling device 7 are attached to the body frame 3, and the cab 2 is placed on the upper part thereof.
The blade 4 is provided in front of the vehicle body frame 3 and is a working machine for scraping the ground and carrying the earth and sand, and is driven by a hydraulic cylinder in accordance with the operation of the blade operation lever.

The ripper 5 is provided on the rear side of the vehicle body frame 3 and cuts and crushes with a traction force by the traveling device 7 by piercing a rock or the like at the tip of the shank protruding substantially vertically downward. Similarly to the blade 4, the ripper 5 is driven by a hydraulic cylinder in accordance with the operation of the ripper operation lever.
The traveling device 7 is capable of traveling on rough terrain by rotating a pair of endless crawler belts 7a respectively provided at the left and right lower portions of the vehicle body frame 3 via a sprocket 9 (see FIG. 2).

[Configuration of Sprocket Segment 10]
As shown in FIGS. 2 and 3 (a) to 3 (c), the sprocket segment 10 according to the present embodiment is divided into sprockets 9 used in a lower traveling body of a tracked vehicle such as a bulldozer 1 in the circumferential direction. This is a substantially arc-shaped member including five teeth, and is formed of chromium molybdenum steel.

Detailed components of the sprocket segment 10 include C (0.4 wt%), Si (0.2 wt%), Mn (1.45 wt%), P (0.01 wt%), S (0.01 wt%). , Cr (0.18 wt%), Mo (0.03 wt%), and B (0.0015 wt%), and the other balance is composed of Fe and inevitable impurities.
In addition, the sprocket segment 10 is integrally formed with an attachment portion 11, a flange portion 12, five tooth portions 13, and a burr removal processing portion 21 (see FIG. 5B).

The attachment portion 11 is a portion that is attached to the drive portion of the lower traveling body when a plurality of sprocket segments 10 are combined to form an annular sprocket, and are shown in FIGS. 3 (a) to 3 (c). As shown, the substantially arcuate sprocket segment 10 is disposed on the innermost side (innermost peripheral side) in the radial direction and protrudes toward the inner peripheral side.
The flange portion 12 is disposed on the outer side (outer peripheral side) in the radial direction of the mounting portion 11 and protrudes on both sides in the axial direction of the substantially arcuate sprocket segment 10 as shown in FIG. Is formed.

  The five tooth portions 13 are formed so as to protrude outward in the radial direction from the outermost peripheral surface (tooth surface 12 a) of the sprocket segment 10. Further, among the five tooth portions 13, the tooth portions 13 arranged at both ends are deformed in advance so that undercut does not occur in consideration of the draft angle of the mold 50 when the sprocket segment 10 is forged. It is formed as a tooth portion 30 (see the solid line in FIG. 15). The tooth part 30 is subjected to a bending process by a bending apparatus 20 described later, and is processed to have the same shape as the other tooth parts 13. In addition, the bending process of the tooth part 30 in which both end sides are deformed in advance so as not to cause this undercut will be described in detail later.

As shown in FIG. 5 (b), the burr removal processing portion 21 is a processing mark obtained by removing the burr portion 14 (see FIG. 4) generated during forging by machining, and the sprocket segment on which the burr portion 14 is formed. It is formed along the vicinity of 10 ridge lines.
As shown in FIG. 4, the burr 14 is formed from the vicinity of the ridgeline of the sprocket segment 10 to the side surface and the end of the mounting portion 11 during finish molding (forging molding). In this embodiment, the burr | flash part 14 is the said edge line vicinity, Comprising: R part (R surface) 13a formed in one edge part in the width direction of the tooth | gear part 13 or along the side surface outside it. Is formed. Therefore, the burr part 14 does not affect the tooth surface 12a, and the tooth surface 12a and the tooth part 13 can be accurately molded.

  Here, the vicinity of the ridgeline of the sprocket segment 10 refers to the vicinity of a line along the ridge connecting the mountain portions formed by the five tooth portions 13. Thereby, it can avoid that the burr | flash part 14 is formed on the tooth surface 12a, and can improve the processing precision of the tooth surface 12a. The mold for manufacturing the molded body 10a of the sprocket segment 10 including the burr 14 (a mold for manufacturing the sprocket segment) 50 and the manufacturing process will be described in detail later.

[Mold 50 for producing sprocket segment 10]
In this embodiment, the manufacturing die 50 shown in FIG. 6 is used in the manufacturing process of the sprocket segment 10 having the above-described configuration.
The mold 50 mainly includes a first mold part 51 serving as an upper mold and a second mold part 52 serving as a lower mold. In the mold 50, the sprocket segment 10 is forged (rough forming, finish forming) in a state where the tooth trace direction is inclined by a predetermined angle with respect to the forging direction with a line connecting the longitudinal ends of the mounting portion 11 as a rotation axis. Is done. At the time of this forging, since the sprocket segment 10 is disposed obliquely in the mold 50, the burr 14 can be formed along the vicinity of the ridgeline of the sprocket segment 10 so as not to be hooked on the tooth surface 12a. Further, since the tooth surface inclined with respect to the forging direction in the mold 50 has a draft angle as it is, it is not necessary to provide a shape and a machining allowance in consideration of the draft angle.

As shown in FIG. 6, the first mold part 51 is arranged as the upper half of the mold 50. As shown in FIG. 7, the first mold part 51 is sequentially arranged in accordance with three steps (crush molding, rough molding, and finish molding). Mold carving is done for molding.
As shown in FIG. 6, the second mold part 52 is arranged as the lower half of the mold 50, and as shown in FIG. , Rough molding, finish molding), and carving for forming in order.

Between the first mold part 51 (see FIG. 7) and the second mold part 52 (see FIG. 8), the above-described sprocket segment is used in the rough forming in the second forming step and the finish forming in the third forming step. 10 is forged in a state in which the tooth trace direction is inclined obliquely with respect to the forging direction. In addition, the inclination of the sprocket segment 10 in the metal mold 50 at the time of this forging is set at a position where the above-described burr portion 14 does not hit the tooth surface 12a, that is, an angle formed along the vicinity of the ridgeline.
Further, in the mold 50 of the present embodiment, as shown in FIG. 6, of the above-described burrs 14, the burrs 14 a on the mounting portion 11 side and the burrs 14 b on the tooth portion 13 side are attached to the die. It is formed so as to be substantially parallel to the surface.

[Bending device 20]
In the present embodiment, the bending portions 20 shown in FIGS. 12A and 12B are used to deform the tooth portions 30 at both ends, which have been deformed in advance so as not to cause an undercut, into a desired shape. Bending is performed.

As shown in FIGS. 12A and 12B, the bending apparatus 20 includes a pair of rotating members 21a and 21b, a press mechanism 22, an upper mold 23a, and a pressing mold (pressing member) 23b. And a lower die 24, support jigs (support portions) 25a to 25c, and an urging member 26 (see FIG. 14A, etc.).
The pair of rotating members 21a and 21b are members that rotate about the rotating shafts 21aa and 21ba, and abut against the tooth portion 30 of the sprocket segment 10 that has been deformed in advance so as not to cause an undercut. And deform into an appropriate shape. Further, the rotating members 21a and 21b are connected at their distal ends by an urging member 26 (see FIG. 14A and the like) described later, and receive an urging force in a direction to bring them closer to each other. Further, the rotating members 21a and 21b are based on the radius r of the curved surface of the tooth surface 12a in order to deform the tooth portion 30 deformed in advance so as not to cause an undercut into an appropriate shape. A turning radius R is set (see FIG. 15). Further, when the tooth portion 30 is bent, the rotating members 21a and 21b are moved by the crank press mechanism 27 (see FIG. 13) so that the upper mold 23a moves downward in the drawing and comes into contact with the rotating members 21a and 21b. , Each receives a force to rotate outward.

The press mechanism 22 includes a nitrogen gas cylinder (pressing mechanism) 22a that presses the pressing mold 23b downward in the vertical direction, an upper mold 23a that contacts and rotates against the rotating members 21a and 21b, and a sprocket segment. And a pressing die 23b that comes into contact with the 10 flange portions 12.
The nitrogen gas cylinder 22a contracts when the upper die 23a moves downward in the figure, and applies a downward repulsive force to the pressing die 23b in contact with the flange portion 12 of the sprocket segment 10.

The upper mold 23a is moved downward in the figure by the crank press mechanism 27 (see FIG. 13) and comes into contact with the rotating members 21a and 21b. As a result, the rotating members 21a and 21b deform the tooth portion 30 deformed in advance of the sprocket segment 10 into a predetermined shape.
The holding die 23b has a substantially arc-shaped surface so as to contact along the shape of the flange portion 12 of the sprocket segment 10.
The holding die 23b that contacts the flange portion 12 of the sprocket segment 10 is pressed downward by a nitrogen gas cylinder (pressing mechanism) 22a to press the sprocket segment 10 against the support portions 25a, 25b, and 25c. is there.

The lower mold 24 forms the bottom of the bending apparatus 20 to which the rotation shafts 21aa and 21ba of the rotation members 21a and 21b and the support jigs 25a to 25c are fixed.
The support jigs 25 a to 25 c are support members that support the tooth surface side of the sprocket segment 10. The support jigs 25 a and 25 b support both ends of the sprocket segment 10, and the support jig 25 c supports the vicinity of the center of the sprocket segment 10.

  The urging member 26 is a winding spring formed of a steel material, and as shown in FIG. 14A and the like, both ends thereof are connected to the vicinity of the distal end portions of the pair of rotating members 21a and 21b. The urging member 26 returns the rotating members 21a and 21b to the initial position by an inward urging force applied to the rotating members 21a and 21b when a bending process described later is completed. That is, the biasing member 26 sets the initial position of the rotating members 21a and 21b according to the length dimension in the equilibrium state.

  In the bending apparatus 20 of the present embodiment, as shown in FIG. 13, the nitrogen gas cylinder 22a contracted with the downward movement of the upper mold 23a in the drawing gives a downward repulsive force to the pressing mold 23b. . As a result, the pressing mold 23b presses the sprocket segment 10 downward. Then, the rotating members 21a and 21b rotate outwardly by the contact with the upper mold 23a along the tooth surfaces 12 of the tooth portions 30 on both end sides deformed in advance so as not to cause an undercut. At this time, an outward force is applied to the tooth portion 30 by the rotating members 21a and 21b, and the tooth portion 30 is bent so as to be deformed into an appropriate shape. The bending process by the bending apparatus 20 will be described in detail later.

<Method for Manufacturing Sprocket Segment 10>
Here, it will be as follows if the manufacturing process of the sprocket segment 10 mentioned above is demonstrated using FIGS. 9-11.
That is, the sprocket segment 10 of the present embodiment is formed from a round bar material into the sprocket segment 10 through the processes shown in FIGS. 9 and 10.

Specifically, as shown in the flowchart of FIG. 11, first, in step S11, the material is heated.
Next, in step S12, the heated round bar-shaped material is crushed in a first molding step in a mold 50 installed in a forging machine such as a forging hammer or press, and as shown in FIG. The approximate shape of the segment 10 is approached.

Next, in step S13, the compacted body is subjected to rough forming with a forging hammer as shown in FIG. 9 in the second forming step in the mold 50. At this time, the burr | flash part 14 is formed along the ridgeline vicinity in the molded object 10a after rough forming.
Next, in step S14, the molded body 10a after the rough molding is subjected to finish molding with a forging hammer as shown in FIG. 9 in the third molding step in the mold 50.

Next, in step S15, as shown in FIG. 9, the deburring process which removes the burr | flash part 14 of the molded object 10a after finish molding with a press is performed. Thereby, the sprocket segment 10 is molded.
Thereafter, in step S16, as shown in FIGS. 10 and 15, among the plurality of tooth portions 13 included in the sprocket segment 10, the tooth portions 30 at both ends are deformed to appropriate positions by the bending device 20 described above. Bend to. The bending process of the tooth portion 13 deformed in advance so as not to cause this undercut will be described in detail later.
Finally, after heat-treating the sprocket segment 10 in step S17, bolt holes and the like are formed by machining as shown in FIG.

<Bending method by bending apparatus 20>
In the present embodiment, as described above, the bending process in step S16 is performed using the bending apparatus 20 shown in FIGS. 12 (a) and 12 (b).

More specifically, first, as shown in FIGS. 12A and 14A, after setting the sprocket segment 10 immediately after forging on the support jigs 25a to 25c, the flange portion of the sprocket segment 10 is set. The upper mold 23 a, the presser mold 23 b, and the press mechanism 22 are set above 12.
Next, as shown in FIG. 13 and FIG. 14B, the upper mold 23 a is pressed downward by the press mechanism 22. At this time, the sprocket segment 10 is pressed downward by the pressing mold 23b while being supported by the support jigs 25a to 25c. At this time, the holding die 23b receives the repulsive force from the nitrogen gas cylinder 22a contracted with the downward movement of the upper die 23a in the figure, and holds down the sprocket segment 10 so as not to fall down or float up. . The sprocket segment 10 is moved by the crank press mechanism 27 moving the upper die 23a downward in the figure in a state where the sprocket segment 10 is in contact with the tip end portions of the rotating members 21a and 21b on the tooth surface 12a inside the tooth portion 30. The rotating member 21a is rotated counterclockwise, and the rotating member 21b is rotated clockwise.

  Here, as shown in FIG. 15, the rotating members 21a and 21b that are rotated by contact with the upper mold 23a that moves downward in the figure by the crank press mechanism 27 are rotated when the tip ends are rotated in an arc shape. In addition, pressure is applied while abutting from the tooth bottom 31 to the tooth tip 32 of the tooth portion 30 deformed in advance so as not to cause an undercut. In addition, in FIG. 15, although the structure by the side of the rotation member 21b is mentioned as an example, it is the same also about the rotation member 21a side.

Next, when the pressing of the upper mold 23a by the press mechanism 22 is completed and the upper mold 23a moves upward, the nitrogen gas cylinder 22a is fully extended and the pressing on the pressing mold 23b is also released. Therefore, as shown in FIG. 14C, the rotating members 21a and 21b are urged inward by the urging force of the urging member 26, and rotated back to a predetermined initial position.
As a result, the tooth portion 30 (see the solid line in the figure) deformed in advance so as not to cause an undercut is appropriately toothed 30a (dotted line in the figure) by the pressing of the rotating members 21a and 21b during rotation. Bending) to deform. Therefore, since the contact area between the rotating members 21a and 21b and the tooth portions 30 whose tip portions rotate in an arc shape is smaller than that of the conventional bending apparatus, a small pressure is applied locally, thereby efficiently. The bending process of the tooth part 30 can be performed. As a result, by using the bending apparatus 20 of the present embodiment, a large facility or the like is required to deform the tooth portion 30 deformed in advance so as not to cause an undercut into the tooth portion 30a having an appropriate shape. Therefore, the bending process can be easily performed with a simple structure and with a small pressure.

Further, in the present embodiment, since the pressure necessary for the deformation is applied downward, the load for holding the sprocket segment 10 being deformed can be reduced.
Furthermore, since the vicinity of the tip end portions of the rotating members 21a and 21b are connected to each other by the urging member 26, the rotating members 21a and 21b can be automatically returned to the initial positions when the bending process is completed. Therefore, it is not necessary to manually return the rotating members 21a and 21b to the initial position every time pressing by the press mechanism 22 is completed, so that the bending process can be made more efficient.

[Comparative example]
Here, the result of comparing the pressure required when the sprocket segment 10 is bent by the bending apparatus 20 of the present embodiment described above with a conventional bending apparatus will be described.
In addition, the sprocket segment 10 used here used a workpiece having a distance L between teeth of L = 509 mm (see FIG. 3B).

Here, the load P applied to the tool necessary for forming is obtained by the following equation.
P = S × σ
Where S is the contact area between the tool and the tooth surface, and σ is the deformation resistance of the material of the sprocket segment 10 (when the steel is hot) (here, 20 kg / mm ² = ² ton / cm ² ).
In the case of the conventional bending apparatus disclosed in Patent Document 1, the load P applied to the tool was 1089 ton.

In the conventional bending apparatus disclosed in Patent Document 2, the load P applied to the tool is 376 tons.
On the other hand, in the bending apparatus 20 according to this embodiment described above, the load P required for pressing was 26 tonnes.
As can be seen from the above results, like the bending device 20 of the present embodiment, the bending of the tooth portion 30 deformed in advance so as not to cause an undercut using the rotation by the rotation members 21a and 21b. As a result, the pressure applied to the apparatus can be greatly reduced as compared with the conventional bending apparatus. Therefore, according to the present embodiment, the apparatus can be simplified and miniaturized as compared with the prior art.

  Specifically, in the case of the conventional bending apparatus disclosed in Patent Documents 1 and 2, it is necessary to use a press apparatus having a pressure capacity of 400 to 1200 tons. On the other hand, in the bending apparatus 20 of this embodiment, it becomes possible to fully shape | mold using the press means whose pressurization capability is about 30 tons. Further, the load applied to the tool can be reduced, and a compact mold for holding the molded product can be used.

In this embodiment, the two roll forming units as the processing tools are moved at a constant included angle (for example, the same angle as the inclination of the external teeth of the sprocket segment 10), so that even when products having different dimensions are formed. It is possible to respond by simply exchanging the roller and the material cradle.
From the above, it can be used for a production line without a large press device, and the entire device can be made smaller than before.

[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.
(A)
In the above-described embodiment, so-called oblique forging is performed in which the sprocket segment 10 is forged while the tooth trace direction is inclined at a predetermined angle with respect to the forging direction with a line connecting the longitudinal ends of the attachment portion 11 as a rotation axis. It was explained as an example. However, the present invention is not limited to this.

  For example, even in the case of so-called vertical forging, in which forging is performed in a state where the tooth trace direction is perpendicular to the forging direction, a sprocket having a tooth portion having a desired shape can be obtained by using the bending apparatus of the present invention. Segments can be manufactured.

(B)
In the above embodiment, the bending apparatus 20 including the pair of rotating members 21a and 21b that are deformed while being in contact with the tooth portions 13 at both ends of the sprocket segment 10 has been described as an example. However, the present invention is not limited to this.
For example, as shown in FIGS. 16A and 16B, a manufacturing apparatus that deforms the tooth portion 30 at one end of the sprocket segment 110 by a single rotating member 121 may be used.

Or the manufacturing apparatus which deform | transforms the tooth | gear part deform | transformed previously so that an undercut may not occur using three or more rotation members may be sufficient.
Even in this case, the tooth portion can be easily deformed into a desired shape with a small force by rotating the tooth portion deformed in advance with the tip portion of the rotating member in contact with the tooth portion. The effect similar to the said embodiment can be acquired.

(C)
In the above embodiment, an example in which the tooth portions 13 at both ends included in the five-tooth sprocket segment 10 are deformed has been described. However, the present invention is not limited to this.
For example, as shown in FIG. 17, a manufacturing apparatus that deforms tooth portions at both ends included in a three-tooth sprocket segment 210 formed from a molded body 210 a may be used.

(D)
In the said embodiment, the example which performs the forge shaping | molding of 3 processes of crushing shaping | molding, rough shaping | molding, and finish shaping | molding was given and demonstrated. However, the present invention is not limited to this.
For example, the sprocket segment may be formed in two stages of crushing and finishing, omitting rough forming.

  The sprocket segment manufacturing apparatus of the present invention can manufacture a sprocket segment of a desired shape at low cost without installing special equipment for deforming the tooth portion or equipment with high pressurization capacity. Since it produces an effect, it can be widely applied to a sprocket segment manufacturing method for sprockets used in various vehicles.

DESCRIPTION OF SYMBOLS 1 Bulldozer 2 Cab 3 Body frame 4 Blade 5 Ripper 7 Traveling device 7a Crawler belt 9 Sprocket 10 Sprocket segment 10a Molded body 11 Attachment part 12 Flange part 12a Tooth surface 13 Tooth part 13a R part 14 Burr part 14a, 14b Burr part 20 Equipment (sprocket segment production equipment)
21 Deburring parts 21a, 21b Rotating members 21aa, 21ba Rotating shaft 22 Press mechanism 22a Nitrogen gas cylinder (pressing mechanism)
23a Upper mold (pressing member)
23b Holding mold 24 Lower mold 25a, 25b, 25c Support jig (support part)
26 Biasing member 27 Crank press mechanism 30 Tooth part 30a Tooth part 31 Tooth base 32 Tooth tip 50 Mold 51 First mold part 52 Second mold part 110 Sprocket segment 210 Sprocket segment 210a Molded body r Radius of tooth surface R Turning radius S step

Japanese Utility Model Publication No. 60-181239 Japanese Unexamined Patent Publication No. 63-026229

Claims (6)

A sprocket segment manufacturing apparatus for deforming a tooth portion forged and molded into a desired shape in consideration of undercut,
A support for supporting the sprocket segment;
A press mechanism that pressurizes the sprocket segment supported by the support portion in a predetermined direction;
Wherein disposed close to the tooth surface of the particular tooth portion of the sprocket segment which is supported at the support unit, when the sprocket segment by the pressing mechanism Ru pressurized, the tooth surfaces of the particular tooth portion of the sprocket segment A rotating member that rotates in an arc shape while the tip portion abuts against the shape of the tooth portion;
An apparatus for manufacturing a sprocket segment. The press mechanism includes a pressing member that abuts on a flange portion opposite to the tooth portion of the sprocket segment, and a pressing mechanism that presses the pressing member.
The sprocket segment manufacturing apparatus according to claim 1. The rotating member rotates so that the tip portion moves from the root of the tooth portion toward the tooth tip.
The sprocket segment manufacturing apparatus according to claim 1 or 2. The turning radius R of the turning member is set according to the size of r of the tooth surface that connects the tooth bottom to the tooth bottom of the tooth portion of the sprocket segment .
The sprocket segment manufacturing apparatus according to any one of claims 1 to 3. A biasing member that biases the tip of the pivoting member to the opposite side of the pivoting direction when the tooth part is deformed;
The sprocket segment manufacturing apparatus according to any one of claims 1 to 4. A plurality of the rotating members are provided,
The sprocket segment manufacturing apparatus according to any one of claims 1 to 5.

Images