JP2008238215A - Method for manufacturing rolling product with helical projection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a rolling product with helical projection capable of reducing waviness along a flank line direction. <P>SOLUTION: A raw material is subjected to rough form rolling, and then finish form rolling. In a rough form rolling region 22, the number of teeth for a part with the large amount of teeth number of a rough form rolling tool 20 engaging with the raw material is defined as Nrough-large, and that for a part with the small amount of teeth number of a rough form rolling tool 20 engaging with the raw material 1 is defined as Nrough-small. In a finish form rolling region, the number of teeth for a part with large amount of teeth number of a finish form rolling tool 30 engaging with a rough form rolled material is defined as Nfinish-large, that for a part with the small amount of teeth number of a finish form rolling tool engaging with a rough form rolled material 4 is defined as Nfinish-small. A region of teeth number Nfinish-small in a finish form rolling region is engaged with a region of teeth number Nrough-large in a rough form rolling region 22, and a region of teeth number Nrough-small in the rough form rolling region 22 is engaged with a region of teeth number Nfinish-large in the finish form rolling region, whereby the product is produced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a helical protrusion-containing rolled product containing helical protrusions. Helical protrusions (rough rolling protrusions, finish rolling protrusions) mean protrusions along at least a part of the windings on which the tooth streaks hang, and the helical teeth forming the protrusions and the worms forming the protrusions. Typical examples include teeth and protruding male screws. Accordingly, the helical protrusion-containing rolled product includes gears such as helical gears and worms, and male screws.

  2. Description of the Related Art Conventionally, a method for manufacturing a rolled product has been developed in which a helically formed tooth is formed by rolling. According to this method, the cutting process is eliminated or simplified, which is advantageous for cost reduction. However, due to the recent demand for higher precision of machine parts, there is an increasing demand for improved precision even for helically formed teeth.

Non-Patent Document 1 is known regarding this technology. According to this document, a pair of rolling tools having a roller die shape having a rolling region having a rolling tool tooth having a helical shape is used. And it rolls with the rolling tool tooth | gear of a pair of rolling tool with respect to the raw material workpiece | work which makes a round bar shape, forms the rolling tooth | gear which forms a helical shape in a raw material workpiece | work, and manufactures a pinion. According to this document, in a rolled tooth having a helical shape, as shown in FIG. 22, a thick portion indicated by a circle and a thin portion indicated by a triangle are formed. Are listed. Further, it is described that waviness occurs along the direction of the tooth trace on the two tooth surfaces facing away from each other that form a helically formed tooth.
Plasticity and processing (Journal of Japan Society for Technology of Plasticity) Vol. 41, No. 469 (2000-2) 151-155

  By the way, due to the recent demand for higher precision of machine parts, there is an increasing demand for improvement of tooth profile accuracy in helically formed teeth, worm teeth, male screws, and the like.

  The present invention has been made in view of the above-described circumstances, and can reduce waviness along the direction of the teeth of a finished rolling projection capable of forming a helically formed rolling tooth, a worm tooth, a male screw, or the like. It is an object of the present invention to provide a method for producing a rolled product containing helical projections that can improve tooth profile accuracy.

(1) A method for producing a helical protrusion-containing rolled product according to aspect 1 includes a rough rolling process region having a rough rolling tool tooth for forming a rough rolled protrusion having a helical shape, A preparation step of preparing a rolling tool having a finish rolling processing region having a finish rolling tool tooth for forming a finish rolling projection having a helical shape;
Rough rolling with a rough rolling tool tooth on a round bar-shaped material workpiece to form a rough workpiece with a rough rolling protrusion having a helical shape and waviness along the tooth line direction. Manufacturing process,
Finish rolling with rough rolling projections of rough workpieces with finish rolling tool teeth, and finish rolling process to form finished rolled product with finish rolling projections forming a helical shape,
In the rough rolling region, the number of teeth of the rough rolling tool teeth that mesh with the workpiece is set to Nrough-large, and the teeth of the portion with less teeth of the rough rolling tool teeth that mesh with the workpiece. The number is Narrow-small,
In the finish rolling process area, the number of teeth in the finish rolling tool tooth that meshes with the rough workpiece is Nfinish-large, and the finish rolling tool tooth that meshes with the rough workpiece has a small number of teeth. When the number is Nfinish-small,
The rough rolling protrusion created in the area of the number of teeth Nough-large in the rough rolling process area is meshed with the area of the number of teeth Nfinish-small in the finish rolling process area, and
It is characterized in that an area having the number of teeth Nfinish-large is meshed with a rough rolling protrusion created in an area having the number of teeth Nrough-small in the rough rolling process area in the finish rolling process area.

  According to the present specification, a helical projection refers to a projection formed along at least a part of a winding in which a tooth line hangs. The helical protrusion-containing rolled product according to the present invention means a rolled product in which a projection along at least a part of a helical winding is formed by rolling. The helical protrusion-containing rolled product according to the present invention includes gears such as helical gears and worms, and male screws.

  According to aspect 1, rough rolling protrusions are created in the rough rolling process. As a result, a rough work having rough rolling protrusions is created. A finish rolling projection is created in the finish rolling process. As a result, a finish-rolled product having finish-rolling protrusions is formed.

  By the way, in the rough rolling process, undulations in which crests and troughs are alternately formed along the tooth line direction are formed on the two tooth surfaces facing each other that form the rough rolling protrusions of the rough workpiece. Is done. Also in the finish rolling process, finish rolling is performed so that waviness is formed in the tooth surface of the finish rolling projection of the workpiece along the tooth line direction. At this time, the undulation generated in the rough rolling process and the undulation generated in the finish rolling process are basically in a reverse phase relationship. For this reason, the height of the wave | undulation in the finish rolling protrusion of a finish roll product is reduced. Thereby, the shape accuracy in the finish rolling projection of the finished roll product is improved. Examples of finished rolled products include gears, worms, screws, and the like.

  (2) According to the manufacturing method of the helical protrusion-containing rolled product according to aspect 2, in the above-described aspect, the rolling tool includes a rough rolling tool having rough rolling tool teeth, and a finish rolling tool. It is formed with a finishing rolling tool having forging tool teeth, a rough rolling tool is formed with one set of rack type tools, and a finishing rolling tool is a set of two racks. It is formed by a mold tool. Rough work can be rolled by operating a set of two rack-type tools. Finished rolls can be rolled by operating a set of two rack-type tools. At this time, the undulation generated in the rough rolling process and the undulation generated in the finish rolling process are basically in a reverse phase relationship. For this reason, the height of the undulation at the finish of the finished rolled product is reduced. Thereby, the shape accuracy in the finish rolling teeth of the finish roll product is improved.

  (3) According to the method for producing a helical protrusion-containing rolled product according to aspect 3, in the above-described aspect, the rolling tool is common in both the rough rolling process and the finish rolling process. The rolling tool teeth and the finish rolling tool teeth are formed on the same surface of a common rolling tool. In this case, it is not necessary to perform an operation for exchanging the rough rolling tool and the finish rolling tool, and productivity is improved.

(4) According to the method for manufacturing the helical protrusion-containing rolled product according to aspect 4, in the above-described aspect, the width dimension D1 in the direction intersecting the rolling direction in the rough rolling region and the finish rolling process The width dimension D2 in the direction intersecting the rolling direction in the region is set to a different size,
In the finish rolling process area, the position of the area with the number of teeth Nfinish-large and the position of the area with the number of teeth Nfinish-small are reversed.
The region that should have the number of teeth Nfinish-large is a region that has the number of teeth Nfinish-small, and the region that should have the number of teeth Nfinish-small is a region that has the number of teeth Nfinish-large. In this case, the rough rolling region and the finish rolling region can be continued in series in the rolling direction. Therefore, the rough rolling process and the finish rolling process can be continuously performed on the material workpiece, and the productivity can be improved.

  According to the present invention, the undulation that occurs in the rough rolling process and the undulation that occurs in the finish rolling process are basically in opposite phases. For this reason, when forming a finished rolled product having finish rolling projections having a helical shape, it is possible to improve the accuracy of the finish rolling projections in the direction of the teeth. Therefore, high-precision and high-quality finish rolling projections can be formed.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. In the preparation process according to the manufacturing method according to the present embodiment, as shown in FIG. 1, a metal material workpiece 1 having a round bar shape and a rough rolling tool 2 shown in FIG. 1 are prepared. Further, a finish rolling tool 3 shown in FIG. 4 is prepared. The metal forming the material workpiece 1 is not particularly limited, and examples thereof include carbon steel, alloy steel (including stainless steel), aluminum alloy, and titanium alloy.

  As shown in FIG. 1, the rough rolling tool 2 is formed of a set of two movable rough rack tools 2a that can be moved synchronously along the rolling direction (arrow A1 direction). FIG. 2 shows a plan view of the rough rack type tool 2a. As shown in FIG. 2, the rough rack type tool 2a includes a rough rolling process region 22 having rough rolling tool teeth 20 inclined with respect to the moving direction (arrow A1 direction) of the rough rack type tool 2a.

  As shown in FIG. 4, the finishing rolling tool 3 is formed of a movable finishing rack type tool 3 a that is movable and can be moved synchronously in the rolling direction (arrow A <b> 2 direction). FIG. 5 shows a plan view of the finishing rack type tool 3a. As shown in FIG. 5, the finishing rack type tool 3a has a finishing rolling processing region 32 having the finishing rolling tool teeth 30 inclined with respect to the moving direction of the finishing rack type tool 3a (the direction of the arrow A2). The rough rolling tool 2 and the finish rolling tool 3 are separate from each other. The pitch of the rough rolling tool teeth 20 (pitch along the axial direction of the workpiece 1) P1 and the pitch of the finishing rolling tool teeth 30 having an inclination (along the axial direction of the workpiece 1). P2) corresponds to P2, and is substantially the same size.

  The surface of the rough rolling tool tooth 20 in the rough rolling region 22 may be roughened (for example, Ra: 0.4 to 0.8 or 0.4 to 0.6). . In this case, slippage between the rough rolling tool teeth 20 and the material workpiece 1 is suppressed. The surface of the finish rolling tool teeth 30 in the finish rolling region 32 is mirror-finished (for example, Ra: 0.1 to 0.3 or 0.1 to 0.2) by lapping or the like. Also good.

  Now, a case where the workpiece 1 is rolled will be described. First, as shown in FIG. 1, the material workpieces 1 are arranged between two sets of rough rack type tools 2 a. Then, by moving the two sets of rough rack type tools 2a in the rolling direction (in the direction of arrow A1), the raw work 1 is rotated around its axis PA, while being rough with respect to the outer periphery of the raw work 1. The rough rolling process is performed by the rough rolling tool teeth 20 in the rough rolling region 22 of the rack type tool 2a, and the rough workpiece 4 is formed. The rough workpiece 4 has a rough rolled tooth 40 (rough rolled protrusion) having a helical shape (a shape along a helical winding).

  Thereafter, the rough workpiece 4 is removed from the rough rack type tool 2a. Then, a finish rolling process is performed on the rough workpiece 4. In this case, the rough rolling teeth 40 of the rough workpiece 4 and the finish rolling tool teeth 30 of the set of two finishing rack tools 3a are phase-matched. After that, as shown in FIG. 4, a set of two finishing rack tools 3a is moved in the rolling direction (arrow A2 direction). As a result, the rough workpiece 4 is finished and rolled by the finish rolling tool tooth 30 of the finish rolling tool 3 with respect to the helical shape (shape along the helical winding) of the rough workpiece 4. As a result, a finished rolled product 5 (see FIG. 7) is formed. In the finished rolled product 5, finished rolled teeth 50 (finished rolling projections) having a helical shape inclined with respect to the axis PA are formed.

  As described above, according to the present embodiment, in the rough rolling process, rough rolling is performed by the rough rolling tool teeth 20 of the rough rolling tool 2 on the metal material workpiece 1 having a round bar shape. As a result, a rough workpiece 4 having a rod shape is formed. The rough workpiece 4 includes a rough rolling tooth 40 having a helical shape. The rough rolled teeth 40 have undulations along the direction of the lines of the rough rolled teeth 40. FIG. 3 shows a profile in which the swell of the rough rolled teeth 40 is enlarged. As shown in FIG. 3, the undulations are formed so that the crests and troughs are alternately continued along the direction of the teeth of the rough rolled teeth 40.

  The reason why the above swell is formed is assumed to be as follows. That is, according to the rough rolling process, the rough rolling tool teeth 20 mesh with the material workpiece 1 in the rough rolling process region 22. When the material workpiece 1 and the rough rolling tool 2 mesh with each other in this way, the number of teeth of the portion with a large number of teeth of the rough rolling tool tooth 20 meshed with the material workpiece 1 in the locus K1 in FIG. (Region shown by ● in FIG. 2). In the locus K2 in FIG. 2, the number of teeth of the portion with a small number of teeth of the rough rolling work 20 that meshes with the material workpiece 1 is defined as “Nrough-small” (a region indicated by ■ in FIG. 2). Here, as for the number of teeth, the number of teeth Nrough-large indicated by ● is larger than the number of teeth Nrough-small indicated by ■ (tooth number Nrough-large> number of teeth Nrough-small). Specifically, in FIG. 2, the number of teeth Nrough-small indicated by ▪ is four, and the number Nrough-large indicated by ● is five. The tracks K1 and K2 are along a direction orthogonal to the moving direction (rolling direction) of the rough rolling region 22.

  Further, in the finish rolling process described above, in the finish rolling process region 32, as shown in FIG. 5, the portion of the finish rolling tool tooth 30 that meshes with the rough workpiece 4 in the locus M1 in FIG. The number of teeth is assumed to be Nfinish-large (the region indicated by the mark ● in FIG. 5). Further, in the trajectory M2 in FIG. 5, the number of teeth of the portion of the finish rolling tool teeth 30 that meshes with the rough workpiece 4 is set to Nfinish-small (a region indicated by ■ in FIG. 5). Here, regarding the number of teeth, the number of teeth Nfinish-large is larger than the number of teeth Nfinish-small (the number of teeth Nfinish-large> the number of teeth Nfinish-small). In FIG. 5, the number of teeth Nfinish-small indicated by ▪ is four, and the number of teeth Nfinish-large indicated by ● is five. The trajectories M1 and M2 are along a direction orthogonal to the moving direction of the finish rolling region 32.

  When the number of teeth is large, the rolling area increases accordingly, so the processing load per unit area becomes small. Here, in the above rough rolling process, as described above, the number of teeth is set such that the number of teeth Nrough-large> the number of teeth Nrough-small. For this reason, the processing load per unit area in the portion with the number of teeth Nrough-large is relatively smaller than the processing load per unit area in the portion with the number of teeth Nrough-small. In this case, in the rough rolled region 22, the portion created by the portion with the number of teeth Nough-large is presumed to be easy to generate undulation peaks because the processing load per unit area is relatively small. .

  In the rough rolling process, the processing load per unit area in the portion with the number of teeth Nrough-small is set to be relatively larger than the processing load per unit area in the portion with the number of teeth Nrough-large. In this case, it is inferred that the portion created by the portion having the number of teeth Nrough-small has a relatively large processing load per unit area, so that it is easy to generate a undulation valley.

  Such a situation (relationship between the number of teeth and the processing load per unit area) is the same in the finish rolling region 32. In other words, the number of teeth in the finish rolling region 32 is such that the number of teeth Nfinish-large> the number of teeth Nfinish-small. For this reason, the processing load per unit area in the portion with the number of teeth Nfinish-large is relatively smaller than the processing load per unit area in the portion with the number of teeth Nfinish-small, which generates undulation peaks. It is assumed that it is easy. In addition, the processing load per unit area in the portion where the number of teeth is Nfinsish-small is relatively larger than the processing load per unit area in the portion where the number of teeth is Nfinish-large, and it is easy to generate undulation valleys. Inferred.

  Therefore, as shown in FIG. 3, the undulations in the direction of the streak of the rough rolled teeth 40 that have undergone the rough rolling process are formed on the two tooth surfaces of the rough rolled teeth 40 facing each other. There is a tendency for each other to turn away from each other, and the valleys of the undulation tend to turn away from each other. For this reason, the portion created in the portion with the number of teeth Nrough-large (the region indicated by the mark ● in FIG. 2) has a rougher shape than the portion created in the portion with the number of teeth Nough-small The tooth thickness of the rolling teeth 40 tends to be relatively thick. Further, the portion created by the portion with the number of teeth Nrough-small (the region indicated by the ■ mark in FIG. 2) is rougher than the portion created by the portion with the number of teeth Nrough-large. The tooth thickness of the rolling teeth 40 tends to be relatively thin.

  Here, the data of FIG. 3 shows that the rough workpiece 4 is formed by the rough rolling process, and the center of the tooth height from one end to the other end in the axial length direction of the two teeth (No1 and No2) of the rough workpiece 4 The vicinity was measured with a tooth profile measuring device. When the rough workpiece 4 is viewed from the tip of the rough workpiece 4, the right tooth surface is the right tooth surface and the left tooth surface is the left tooth surface. The left half of FIG. 3 shows the left tooth surfaces of No. 1 and No. 2 of the rough workpiece 4. The right half of FIG. 3 shows the No. 1 and No. 2 right tooth surfaces of the rough workpiece 4. The right side of the left tooth surface is the gingival part, and the left side of the right tooth surface is the gingival part.

  According to the present embodiment, when the finish rolling process is performed after the rough rolling process, the rough rolling teeth 40 of the rough workpiece 4 subjected to the rough rolling process and the finishing rolling tool 3 are finished. The meshing phase with the rolling tool teeth 30 is adjusted. In this case, the number of teeth Nfinish of the finish rolling process region 32 of the finish rolling tool 3 is compared with the region created by the number of teeth Nrough-large in the rough rolling process region 22 of the rough rolling tool 2. The finished rolled teeth 50 are created by meshing the -small region. In addition, the number of teeth Nfinish- in the finish rolling region 32 of the finish rolling tool 3 is compared with the region created in the portion of the number Nrough-small in the rough rolling region 22 of the rough rolling tool 2. The finished rolled teeth 50 are created by meshing large areas.

  If the finish rolling process is performed under such conditions, the swell in the rough rolling process and the swell in the finish rolling process are substantially offset. That is, the undulation peak in the rough rolling process corresponds to the undulation valley in the finish rolling process. Similarly, the undulation valley in the rough rolling process corresponds to the undulation peak in the finish rolling process. As a result, the undulations in the finished rolled teeth 50 are substantially offset. Therefore, the accuracy in the direction of the tooth trace in the finished rolled tooth 50 of the finished rolled product 5 is improved.

  FIG. 6 shows a state in which the waviness in the rough rolling process and the waviness in the finish rolling process are substantially offset, and the accuracy in the tooth trace direction is improved. That is, FIG. 6 shows the undulation in the direction of the teeth in the two tooth surfaces facing away from each other of the finished rolled tooth 50. As shown in FIG. 6, the ridges and valleys of the undulation are reduced, the smoothness is improved in the direction of the streaks of the finished rolled teeth 50, and the streaks in the direction of the streaks of the finished rolled teeth 50 It can be seen that the error is reduced.

  The data shown in FIG. 6 uses the finished rolled product 5 and the tooth profile tooth near the center of the tooth height from one end of the two teeth (No. 1 and No. 2) of the finished rolled product 5 to the other end in the axial length direction. It is measured by a streak measuring device. When the finished rolled product 5 is viewed from the tip of the finished rolled product 5, the right tooth surface is the right tooth surface and the left tooth surface is the left tooth surface. The left half of FIG. 6 shows the No. 1 and No. 2 left tooth surfaces of the finished rolled product 5. The right half of FIG. 6 shows the No. 1 and No. 2 right tooth surfaces of the finished rolled product 5. The right side of the left tooth surface is the gingival part, and the left side of the right tooth surface is the gingival part.

  By the way, in the field of metal processing, generally, if the base material is the same, the greater the amount of processing (processing load per unit area), the greater the amount of work hardening. The smaller the processing amount (processing load per unit area), the smaller the work hardening amount. Regarding this point, according to the present embodiment, as described above, the number of teeth in the rough rolling process is such that the number of teeth Nrough-large> the number of teeth Nrough-small. The processing load per area is relatively smaller than the processing load per unit area in the portion where the number of teeth is Narrow-small. As a result, the work hardening amount of the portion created by the portion having the number of teeth Nrough-large is made relatively smaller than the work hardening amount of the portion created by the portion having the number of teeth Nrough-small. Then, according to the finish rolling process, the region of the number Ntooth-small in the finish rolling region 32 is meshed with the region created in the portion of the number Nrough-large in the rough rolling region 22. A finished rolled tooth 50 is created. In addition, the region created in the rough rolling region 22 of the rough rolling tool 2 of the rough rolling tool 2 is meshed with the region of the finish rolling region 32 having the number of teeth Nfinish-large. A finished rolled tooth 50 is created.

  For this reason, in general, a region where the work hardening amount is relatively large in the rough rolling step is a region where the work hardening amount is relatively small in the finish rolling step. In addition, the region where the work hardening amount is relatively small in the rough rolling process is a region where the work hardening amount is relatively large in the finish rolling step. For this reason, it is advantageous to suppress the local variation of the work hardening amount for the finish rolling teeth 50 in which both the rough rolling process and the finish rolling process are performed.

  In the present embodiment, it is more effective that the number of teeth of the finished rolled teeth 50 (the rough rolled teeth 40 of the rough workpiece 4) of the finished rolled product 5 is smaller. The reason for this is that the smaller the number of teeth, the greater the difference in the processing load per unit area between the rough rolling process and the finish rolling process per tooth. The number of teeth of the finished rolled teeth 50 of the finished rolled product 5 and the twist angle β of the finished rolled teeth 50 with respect to the axis PA are not particularly limited, but the number of teeth is exemplified as 10 or less, and further 8 Hereinafter, 5 or less is exemplified. The twist angle β is exemplified by 88 ° or less, and further exemplified by 75 ° or less and 65 ° or less.

(Test example)
FIG. 8 shows the measurement result of the tooth streak error actually tested in the state where the number of teeth of the finished rolled teeth 50 (twist angle β: 45 °) of the finished rolled product 5 is set to 2. FIG. 8 shows the relationship between the phase difference between the rough rolling tool tooth 20 and the finish rolling tool tooth 30 and the tooth streak error of the finish rolling tooth 50 of the finished rolled product 5. As shown by the characteristic line in FIG. 8, when the phase difference is 90 °, the tooth trace error is suppressed most. Since there are two teeth, when the phase difference is 90 °, the undulation formed by the rough rolling tool teeth 20 and the undulation formed by the finish rolling tool teeth 30 are basically opposite in phase. This is presumed to be The phase difference is preferably selected according to the number of teeth of the finished rolled teeth 50 of the finished rolled product 5. For example, when the number of teeth is 3, the phase difference is preferably 60 °. When the number of teeth is 4, the phase difference is preferably 45 °.

(Embodiment 2)
9 to 12 show the second embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. Hereinafter, a description will be given centering on differences from the first embodiment. As shown in FIG. 10 and FIG. 12, the pitch P1 of the rough rolling tool teeth 20 of the rough rolling tool 2 and the finish rolling tool of the finish rolling die are formed. It corresponds to the pitch P2 of the teeth 30 and is substantially the same.

  Further, the width dimension of the rough rolling region 22 by the rough rolling tool teeth 20 (the width dimension in the direction orthogonal to the arrow A1 direction as the rolling direction) is defined as D1 (see FIG. 10). The width dimension (width dimension in the direction orthogonal to the arrow A2 direction, which is the rolling direction) of the finish rolling process region 32 by the finish rolling tool teeth 30 is defined as D2 (see FIG. 12).

  Here, D1 and D2 are set to different sizes. Specifically, D1> D2. As shown in FIG. 12, in the finish rolling region 32, a region corresponding to ΔDa is formed on one side in the width direction. Furthermore, a region corresponding to ΔDb is formed on the other side in the width direction. The finish rolling tool teeth 30 are not formed in the regions ΔDa and ΔDb.

  Assuming that the region ΔDa and the region ΔDb exist in the finish rolling region 32, as can be understood from FIG. 12, in the locus K1, the teeth 30x and the teeth 30y located on the end side in the width direction should remain. In the trajectory K1, the total number of teeth should be five.

  However, as shown in FIG. 12, there is no portion corresponding to the region ΔDa and the region ΔDb in the finish rolling region 32, and therefore there are no teeth 30x and teeth 30y on the end side in the width direction in the locus K1, Eventually, the total number of teeth 30u, 30v, and 30w will be 3 (3 are marked with ■). ΔDa corresponds to about ½ of the pitch P2 of the finish rolling tool teeth 30. ΔDb corresponds to about ½ of the pitch P2.

  As described above, if there are regions ΔDa and ΔDb in which the finish rolling tool teeth 30 are not formed on both sides in the width direction of the finish rolling region 32, the number of teeth in the finish rolling region 32 is present. The position of the Nfinish-large area and the position of the Nfinish-small area are reversed. As a result, in the finish rolling region 32, if the regions ΔDa and ΔDb do not exist, the regions that should have the number of teeth Nfinish-large are the regions ΔDa and ΔDb. Therefore, the number of teeth Nfinish- It becomes a small area. Similarly, the region that should have the number of teeth Nfinish-small becomes the region of the number of teeth Nfinish-large due to the phase inversion.

  Also in the present embodiment, when the material workpiece 1 and the rough rolling tool 2 mesh with each other in the rough rolling process, the number of teeth of the portion having a large number of teeth of the rough rolling tool teeth 20 meshed with the material workpiece 1 is determined. Narrow-large (area indicated by ● in FIG. 10). The number of teeth of the portion with a small number of teeth of the rough rolling tool teeth 20 meshing with the material workpiece 1 is defined as Narrow-small (a region indicated by ■ in FIG. 10). Regarding the number of teeth, the number of teeth Nrough-large is larger than the number of teeth Nrough-small (the number of teeth Nrough-large> the number of teeth Nrough-small). Specifically, according to FIG. 10, the number of teeth Nrough-small indicated by ▪ is four, and the number of teeth Nrough-large indicated by ● is five.

  Further, in the finish rolling process region 32, the number of teeth in the portion of the finish rolling tool teeth 30 that meshes with the rough workpiece 4 is set to Nfinish-large (region indicated by ● in FIG. 12). The number of teeth in the portion of the finish rolling tool teeth 30 that meshes with the rough workpiece 4 with a small number of teeth is defined as Nfinish-small (a region indicated by ■ in FIG. 12). Regarding the number of teeth, the number of teeth Nfinish-large indicated by ● is larger than the number of teeth Nfinish-small indicated by ■ (tooth number Nfinish-large> number of teeth Nfinish-small). Specifically, according to FIG. 12, the number of teeth Nfinish-small indicated by ▪ is three, and the number of teeth Nfinish-large indicated by ● is four. Thus, the number of teeth Nfinish-large> the number of teeth Nfinish-small.

  Also in the present embodiment, as in the first embodiment, when performing the finish rolling step, the meshing phase between the rough rolling teeth 40 of the rough workpiece 4 subjected to the rough rolling process and the finishing rolling tool teeth 30 is performed. Adjust. As a result, the region of the number N of teeth in the finish rolling region 32 is meshed with the region created in the region of the number N of teeth in the rough rolling region 22 of the rough rolling tool 2. A finished rolled tooth 50 is created. In addition, the region created in the region of the number N teeth of the rough rolling region 22 in the rough rolling region 22 of the rough rolling tool 2 is engaged with the region of the number N teeth of finish rolling region 32. In addition, a finished rolled tooth 50 is created. If finish rolling is performed under such conditions, as in the first embodiment, the undulation in the rough rolling process and the undulation in the finish rolling process are substantially offset, and the tooth trace of the finished rolling tooth 50 is obtained. Direction accuracy is improved.

(Embodiment 3)
13 and 14 show the third embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. As shown in FIG. 13, the common rolling die 8 performs both rough rolling and finish rolling, and is formed by a set of two rack-type tools 8a. Rough rolling region 22 having rough rolling tool teeth 20 inclined with respect to the rolling direction (in the direction of arrow A1) is provided on the surface 8x (same surface) facing each other of the set of two rack tools 8a. And the finishing rolling process area | region 32 which has the tool teeth 30 for finishing rolling inclined with respect to the rolling direction (arrow A1 direction) is arrange | positioned in series in the rolling direction (arrow A1 direction). Furthermore, as shown in FIG. 14, in the rack-type tool 8a, a chamfered portion 8e is formed on the outer edge of the finish rolling region 32 in the width direction (direction perpendicular to the rolling direction). The chamfered portion 8e is a region corresponding to the region ΔDa and the region ΔDb in FIG. 12, and has no tool teeth.

  Since the chamfered portion 8e functioning as the region ΔDa and the region ΔDb is formed in this way, as shown in FIG. 14, the rough rolling region 22 of the rough rolling tool tooth 20 having a helical shape is formed. The width dimension D1 (width dimension in a direction intersecting the rolling direction) and the width dimension D2 (finishing direction intersecting the rolling direction) of the finish rolling region 32 by the finish rolling tool teeth 30 having a helical shape. The width dimension is set to a different size. Specifically, D1> D2.

  Furthermore, since the chamfered portion 8e corresponding to the region ΔDa and the region ΔDb is formed in the rack type tool 8a, as described above, in the finish rolling region 32, the position of the region of the number of teeth Nfinish-large, The position of the region of the number of teeth Nfinish-small is reversed. Therefore, if the region ΔDa and the region ΔDb do not exist, the region that should have the number of teeth Nfinish-large has a phase reversed due to the presence of the region ΔDa and the region ΔDb, and becomes a region with the number of teeth Nfinish-small. Similarly, the region that should have the number of teeth Nfinish-small becomes the region of the number of teeth Nfinish-large due to the phase inversion.

  As a result of the above, as shown in FIG. 14, the rough rolling region 22 and the finish rolling region 32 in the rack-type tool 8a are continuously arranged in series in the rolling direction (arrow A1 direction). Yes. For this reason, it becomes possible to continuously perform both the rough rolling process and the finish rolling process on the material workpiece 1, thereby improving productivity. In particular, when shifting from the rough rolling process to the finish rolling process, the rough rolling teeth 40 of the rough workpiece 4 and the finish rolling tool teeth 30 of the finishing rolling processing region 32 are not phased. Good and increase productivity.

  If both the rough rolling process and the finish rolling process are performed as described above, the swell in the rough rolling process and the swell in the finish rolling process are substantially offset as described above. Therefore, the accuracy in the tooth trace direction is improved in the finished rolled tooth 50.

  By the way, as shown in FIG. 14, the length in the rolling direction (arrow A1 direction) of the rough rolling region 22 is L1, and the length in the rolling direction (arrow A1 direction) of the finish rolling region 32 is as follows. Shown as L2. According to the present embodiment, L1 = L2 and L1≈L2 may be set according to the type or application of the finished rolled product 5. Moreover, it is good also as L1 <L2 and L1> L2. For example, when the rolling tooth module is small, since the engraving ratio of the rolling teeth is small, the length L1 in the rolling direction of the rough rolling region 22 is relatively shortened, and the finish rolling process is performed. The length of the region 32 in the rolling direction can be set to L1 <L2 by relatively increasing L2. Further, when the module is large, the engraving of the rolling teeth is relatively large, so that L1> L2.

(Embodiment 4)
FIG. 15 shows a fourth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. As shown in FIG. 15, the common rolling die 8B performs both the rough rolling step and the finish rolling step, and is formed by a set of two rack type tools 8b (in FIG. 15, one piece). Only shown). The surface 8x (same surface) of the set of two rack-type tools 8b includes a rough rolling region 22 having a rough rolling tool tooth 20 inclined with respect to the rolling direction (arrow A1 direction), and a rolling The finish rolling region 32 having the finish rolling tool teeth 30 inclined with respect to the forming direction (arrow A1 direction) is arranged in series in the rolling direction (arrow A1 direction) via the chamfer 8e. ing. Tool teeth are not formed on the chamfered portion 8e. The width dimension D1 of the rough rolling region 22 and the width dimension D2 of the finish rolling region 32 are substantially the same.

  In shifting from the rough rolling step to the finish rolling step, it is preferable to adjust the meshing phase between the rough rolling teeth 40 of the rough workpiece 4 and the finishing rolling tool teeth 30 in the finish rolling region 32. Depending on the number of teeth of the finish rolling teeth 50, it is preferable to adjust the position by moving the rough workpiece 4 along the axis PA when finishing the rough workpiece 4 subjected to the rough rolling process. .

(Embodiment 5)
FIG. 16 shows a fifth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. As shown in FIG. 16, the common rolling die 8C performs both the rough rolling step and the finish rolling step, and is formed by a set of two rack type tools 8c. The surface 8x (same surface) of the rack-type tool 8c is chamfered with a rough rolling region 22 having rough rolling tool teeth 20 and a finish rolling region 32 having finish rolling tool teeth 30. It arrange | positions in parallel in the rolling direction (arrow A3, A4 direction) via the part 8f. As shown in FIG. 16, in the rack-type tool 8c, a chamfered portion 8f is formed between the finish rolling region 32 and the rough rolling region 22 arranged in parallel with each other. Tool teeth are not formed on the chamfered portion 8f.

  In rolling, the rack type tool 8c is moved in the rolling direction (arrow A3 direction) with respect to the workpiece 1. After performing the rough rolling process in this manner, the rough work 4 and the rack type tool 8c are relatively moved so that the rough work 4 faces the finish rolling process region 32 of the rack type tool 8c. Further, the meshing phase between the rough rolling teeth 40 of the rough workpiece 4 subjected to the rough rolling process and the finish rolling tool teeth 30 is adjusted. In this state, the rack type tool 8c is moved back in the rolling direction (arrow A4 direction) with respect to the rough workpiece 4, and a finish rolling process is performed.

In the finish rolling process, as described above, an area having the number of teeth Nfinish-small in the finish rolling process area 32 is compared with the area created in the rough-rolling process area 22 with the number of teeth Nrough-large. Engage to create rolled teeth. Further, a rolling tooth is created by meshing a region having the number of teeth Nfinish-large in the finish rolling region 32 with a region created in the portion having the number Nrough-small of teeth in the rough rolling region 22. If the finish rolling process is performed under such conditions, as described above, the undulation in the rough rolling process and the undulation in the finish rolling process are substantially offset. Therefore, the accuracy of the direction of the streak is improved in the finished rolled tooth 50 (Embodiment 6).
FIG. 17 shows a sixth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. In the following, different parts will be mainly described. As shown in FIG. 17, the common rolling die 8D performs both the rough rolling step and the finish rolling step, and is formed by a set of two rack type tools 8d. On the same surface of the rack-type tool 8d, a rough rolling region 22 having rough rolling tool teeth 20 inclined with respect to the rolling direction (arrow A1 direction) and the rolling direction (arrow A1 direction). A finish rolling process region 32 having the finish rolling tool teeth 30 inclined with respect to the rolling direction is arranged in series in the rolling direction (arrow A1 direction).

  At the time of rolling, if the rack-type tool 8d is moved in the rolling direction (arrow A1 direction) with respect to the material workpiece 1, the rough rolling process and the finish rolling process are continuously performed. Also in the present embodiment, in the finish rolling process, an area having the number of teeth Nfinish-small in the finish rolling process area 32 is compared with the area created in the rough-rolling process area 22 with the number of teeth Nrough-large. Create by biting. In addition, an area having the number of teeth Nfinish-large is meshed and created in the finish rolling process area 32 with an area created in the rough rolling process area 22 having the number of teeth Nrough-small. If finish rolling is performed under such conditions, as described above, the swell in the rough rolling process and the swell in the finish rolling process are substantially offset. Therefore, the accuracy in the tooth trace direction is improved in the finished rolled tooth 50.

(Embodiment 7)
18 and 19 show the seventh embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. Hereinafter, the description will focus on the different parts. The rough rolling tool 2F is formed by a set of two rough pinion type tools 200 that can move synchronously in the rolling direction, and has a rough rolling tool tooth 20F having a helical shape. A processing region 22F is provided. The rough rolling process is performed by rotating the rough pinion type tool 200 while holding the material workpiece 1 rotatably by the workpiece holder 9.

  Further, as shown in FIG. 19, the finishing rolling tool 3F is formed of a movable pair of finishing pinion tools 300 that can move synchronously in the rolling direction, and has a helical shape. A finish rolling region 32F having finish rolling tool teeth 30F is provided. While the rough work 4 is rotatably held by the work holder 9, the finish pinion type tool 300 is rotated to perform the finish rolling process.

  The rough rolling tool 2F and the finish rolling tool 3F are separate from each other. The pitch of the rough rolling tool teeth 20F having a helical shape and the pitch of the finish rolling tool teeth 30F having a helical shape correspond to each other and are substantially the same size. . Here, one set of two rough pinion tools 200 is a fixed side, and the other is a movable side. Of the two finishing pinion type tools 300, one is a fixed side and the other is a movable side.

(Embodiment 8)
FIG. 20 shows an eighth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. Hereinafter, the description will focus on the different parts. In the present embodiment, the worm (see FIG. 20) is formed by the rough rolling process and the finish rolling process. The worm has a protrusion along the helical winding.

(Application form)
FIG. 21 shows an application form. As shown in FIG. 21, the small motor with a reduction gear includes a housing 400, a rotor 402 accommodated in the housing 400 via a bearing 401, a deceleration helical gear 420 accommodated in the housing 400, and a helical gear 420. And an output shaft 430 coupled to each other. The rotor 402 has a shaft 403 and a rotor core 404, and rotates around the axis line Pc by a rotating magnetic field generated between the fixed core fixed to the housing 400. On the outer peripheral portion of the shaft 403 of the rotor 402, a helical 408 that meshes with the helical gear 420 is formed. The helical 408 is formed by the rolling method described above. The diameter of the pitch circle of the helical gear 420 is made larger than the diameter of the helical pitch circle of the shaft 403. When the rotor 402 rotates, the helical gear 420 rotates about the axis Pd by the meshing of the shaft 403 with the helical gear 420, and the output shaft 430 rotates about the axis Pd. The shaft length dimension H of the shaft 403 is kept small, and the dimension H1 of the housing 400 is kept small, which is advantageous for downsizing.

(Other)
According to the above-described embodiment, the present invention is applied to rolling helical gears. However, the present invention is not limited to this, and is suitable for rolling worms and male threads that can function as a rolled product containing helical projections. Can be applied. According to the application mode described above, the present invention is applied to a small motor with a speed reducer. However, the present invention is not limited thereto, and any gear member including a helical gear, a gear device including a worm, and a screw member including a male screw may be used. Applicable. Structures and functions specific to one embodiment can be applied to other embodiments.

FIG. 3 is a configuration diagram schematically showing a rough rolling process according to the first embodiment. FIG. 3 is a plan view schematically showing a rough rolling tool tooth of a rough rolling tool used in the rough rolling step according to the first embodiment. It is a graph which concerns on Embodiment 1 and shows the tooth trace curve of the rough rolling tooth in the rough workpiece | work after implementing a rough rolling process. It is a block diagram which concerns on Embodiment 1 and shows a finish rolling process typically. FIG. 3 is a plan view schematically showing a finish rolling tool tooth of a finish rolling tool used in the finish rolling step according to the first embodiment. It is a graph which concerns on Embodiment 1 and shows typically the tooth trace curve of the finish rolling tooth in the finish rolling product after implementing a finish rolling process. FIG. 3 is a side view schematically showing a finished rolled product after the finish rolling step according to the first embodiment. It is a graph which shows a test result and shows typically a relation between phase difference and tooth-pick error. It is a block diagram which concerns on Embodiment 2 and shows a rough rolling process typically. FIG. 10 is a plan view schematically showing rough rolling tool teeth of a rough rolling tool used in the rough rolling process according to the second embodiment. It is a block diagram which concerns on Embodiment 2 and shows a finish rolling process typically. FIG. 6 is a plan view schematically showing finish rolling tool teeth of a finish rolling tool used in the finish rolling step according to the second embodiment. FIG. 10 is a configuration diagram schematically showing a rolling process according to the third embodiment. FIG. 10 is a plan view schematically showing rolling tool teeth of a rolling tool used in the manufacturing process according to the third embodiment. FIG. 10 is a plan view schematically showing rolling tool teeth of a rolling tool used in the rolling process according to the fourth embodiment. FIG. 10 is a plan view schematically showing rolling tool teeth of a rolling tool used in the rolling process according to the fifth embodiment. FIG. 10 is a plan view schematically showing rolling tool teeth of a rolling tool used in a rolling process according to the sixth embodiment. It is a top view which shows typically the state which concerns on Embodiment 7 and is implementing the rough rolling process with the tool for rough rolling. It is a top view which shows typically the state which concerns on Embodiment 7 and is implementing the finish rolling process with the tool for finish rolling. FIG. 10 is a perspective view of a worm according to Embodiment 8. It is sectional drawing of a small motor with a reduction gear in connection with an application form. It is a block diagram currently disclosed by the nonpatent literature 1. FIG.

Explanation of symbols

  1 is a material workpiece, 2 is a rough rolling tool, 20 is a rough rolling tool tooth, 22 is a rough rolling processing region, 3 is a finishing rolling tool, 30 is a finishing rolling tool tooth, and 32 is a finishing. Rolling region, 4 is a rough workpiece, 40 is a rough rolled tooth (rough rolled protrusion), 5 is a finished rolled product, and 50 is a finished rolled tooth (finished rolled protrusion).

Claims (4)

Rough rolling region with rough rolling tool teeth for forming helically rolled protrusions and a finish rolling tool for forming helically shaped finished rolling protrusions A preparation step of preparing a rolling tool having a finish rolling process region with teeth;
Rough rolling is performed on the material workpiece having a round bar shape by the rough rolling tool teeth to form a rough workpiece having a rough rolling protrusion having a helical shape and undulation along the direction of the teeth. Rolling process,
A finish rolling step of forming a finished rolled product having finish rolling projections having a helical shape by finish rolling with the finish rolling tool teeth with respect to the rough rolling projections of the rough workpiece. Carried out,
In the rough rolling region, the number of teeth of the rough rolling tool teeth meshing with the material workpiece is set to Nrough-large, and the number of teeth of the rough rolling tool teeth meshing with the material workpiece is The number of teeth in the small part is Narrow-small,
In the finish rolling region, the number of teeth of the finishing rolling tool teeth that mesh with the rough workpiece is Nfinish-large, and the number of teeth of the finishing rolling tool teeth that mesh with the rough workpiece. When Nfinish-small is the number of teeth of the part with less
Meshing with the rough rolling protrusions created in the area of the number of teeth Nrough-large in the rough rolling process area, the area of the number of teeth Nfinish-small in the finish rolling process area; and
The rough rolling protrusion created in the area of the number of teeth Nrough-small in the rough rolling region is meshed with the region of the number Nteeth-finish in the finish rolling region A method for producing a rolled product containing a comb-like protrusion. In claim 1, the rolling tool is formed of a rough rolling tool having the rough rolling tool teeth and a finish rolling tool having the finish rolling tool teeth.
The rough rolling tool is formed of a set of two rack type tools, and the finish rolling tool is formed of a set of two rack type tools. Manufacturing method of protrusion containing rolled product.   In Claim 1, the said rolling tool is common to both the said rough rolling process and the said finish rolling process, The said rough rolling tool tooth and the said finish rolling tool tooth are common A method for producing a rolled product containing helical protrusions, which is formed on the same surface of the rolling tool. In one of Claims 1-3, the width dimension D1 of the direction which cross | intersects the rolling direction in the said rough rolling process area | region, and the width dimension D2 of the direction which cross | intersects the rolling direction in the said finish rolling process area | region. Is set to a different size,
In the finish rolling process region, the position of the number of teeth Nfinish-large and the position of the number of teeth Nfinish-small are reversed, and the region that should become the number of teeth Nfinish-large by reversal is the number of teeth Nfinish-large. A method for producing a rolled product containing helical protrusions, characterized in that a region that is supposed to be a small region and that should have a number of teeth Nfinish-small is a region that has a number of teeth Nfinish-large.

Images