JP2012166216A - Tooth shape rolling tool, and method for manufacturing gear product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tooth shape rolling tool capable of improving the lifetime of the tool by reducing surface pressure on the tooth shape rolling tool while securing desired tooth depth and an addendum shape of a product, and a method for manufacturing a gear product.SOLUTION: The tooth shape rolling tool 10 forms tooth shapes by pressing processing teeth 11 each of which includes a tooth bottom part 12 and an addendum part 13 to a workpiece. The tooth bottom part 12 is formed with a relief part 12a which the workpiece does not contact, and at least one tooth is formed with a straightening part 12b which contacts the workpiece in a finished dimension of the workpiece. The addendum part 13 is formed with a processing part 13a which contacts the workpiece, and at least one tooth adjacent to the straightening part 12b is formed with a non-processing part 13b which the workpiece does not contact when the straightening part 12b contacts the workpiece.

Description

  The present invention relates to a tooth profile rolling tool that presses against a workpiece to roll a tooth profile, and a gear product manufacturing method. More specifically, the present invention relates to a tooth profile rolling tool and a gear product manufacturing method capable of reducing the surface pressure applied to the tooth profile rolling tool and improving the tool life.

  2. Description of the Related Art Conventionally, a rolling technique is known in which a rolling tool is pressed against a workpiece and a tooth profile is formed by synchronizing the rotation of the workpiece with the movement of the rolling tool. In this technique, while moving a tooth profile rolling tool provided with processing teeth on the outer peripheral portion in synchronization with the rotation of the workpiece, the inner peripheral portion (in the case of internal tooth rolling) or the outer peripheral portion (outer portion) In the case of tooth rolling, the tooth profile is formed by rolling the workpiece with the processed teeth of the tooth profile rolling tool.

  For example, when manufacturing a gear product having internal teeth, a tooth profile rolling tool is arranged on the inner periphery of a cylindrical workpiece, and the processing teeth of the tooth profile rolling tool are pushed onto the inner periphery of the cylindrical workpiece. Forcibly move relative to the contact and rotate. At that time, while successively changing the distance between the rotation center of the tooth profile rolling tool and the center of the cylindrical workpiece, the processing teeth of the tooth profile rolling tool are pushed into the inner peripheral surface of the cylindrical workpiece, A tooth profile is formed (Patent Document 1).

Japanese Patent No. 3947204

However, in the rolling technology described above, the desired product toothpaste and tooth tip shape are secured by applying the tooth tip formed on the workpiece to the bottom of the processed tooth provided in the tooth profile rolling tool at the end of rolling. Therefore, the surface pressure (stress) applied to the processing teeth of the tooth profile rolling tool is increased. For this reason, there is a problem that the tool life is shortened.
Here, in order to reduce the surface pressure applied to the processing teeth of the tooth profile rolling tool, it is only necessary that the tooth tip formed on the workpiece does not contact the bottom of the processing teeth of the tooth profile rolling tool. However, in such a case, a convex shape remains in the tooth tip portion formed on the workpiece, and a desired product tooth depth and tooth tip shape cannot be ensured.

  Therefore, the present invention has been made to solve the above-described problems, and while reducing the surface pressure applied to the tooth profile rolling tool while ensuring the desired product tooth depth and tooth tip shape, the tool life is improved. It is an object of the present invention to provide a method for manufacturing a tooth profile rolling tool and a gear product that can be achieved.

  One form of this invention made | formed in order to solve the said subject is a tooth profile rolling tool which shape | molds a tooth profile by pressing the process tooth provided with a tooth bottom part and a tooth tip part to a workpiece | work, In the said tooth bottom part, a workpiece | work The at least one tooth is formed with a correction portion that contacts the workpiece with the finished dimension of the workpiece, and the tooth tip portion has a processed portion that contacts the workpiece. In addition, at least one tooth adjacent to the correction portion is formed with a non-working portion where the workpiece does not contact when the correction portion is in contact with the workpiece.

  In this tooth profile rolling tool, since the relief portion where the workpiece does not contact at the time of tooth profile rolling is formed at the tooth bottom portion, the surface pressure acting on the machining tooth can be reduced. In addition, since at least one tooth of the tooth bottom part is formed with a correction part that comes into contact with the work with the finished dimension of the work, even if a convex part is formed on the tooth tip of the work, the correction part corrects the convex part. Thus, the desired product toothpaste and tooth tip shape can be ensured.

  Here, when the tooth tip convex portion of the workpiece is corrected, a large surface pressure acts on the processing teeth adjacent to the correction portion, so that the tool may be damaged from the correction portion. For this reason, in this tooth profile rolling tool, a processing portion that contacts the workpiece is provided at the tooth tip portion, and at least one tooth adjacent to the correction portion does not contact the workpiece when the correction portion contacts the workpiece. A processing section is provided. By providing such a non-processed part at the tooth tip part, the surface pressure acting on the processed tooth can be reduced when the correction part corrects the tooth tip convex part of the workpiece. Therefore, it is possible to prevent the tool from being damaged from the correction portion.

  As described above, according to this tooth profile rolling tool, it is possible to improve the tool life by lowering the surface pressure applied to the processing teeth while securing the desired product tooth depth and tooth tip shape.

  In the above-described tooth profile rolling tool, the inner teeth may be molded by pressing against the inner peripheral portion of the workpiece, or the outer teeth may be molded by pressing against the outer peripheral portion of the workpiece.

  As described above, in this tooth profile rolling tool, both the internal teeth and the external teeth can be rolled, and the surface pressure applied to the processing teeth is lowered during the tooth profile rolling to improve the tool life and The product toothpaste and tip shape can be secured.

  In the above-mentioned tooth profile rolling tool, when the non-machined portion is formed on only one tooth adjacent to the orthodontic portion, the non-machined portion is a tooth on the front side in the tool movement direction with respect to the orthodontic portion. Preferably it is formed.

  When a tooth profile is formed at the processing portion of the tooth tip portion of the tool, the stress acting on the base of the processing tooth increases on the rear side in the tool movement direction on the processing tooth. For this reason, it is considered that forming the non-machined part on the tooth on the front side in the tool movement direction with respect to the correction part has a larger effect of reducing the amplitude of the stress received by the root of the machined tooth. Thereby, it can prevent reliably that a tool is damaged from the correction | amendment part.

  In the above-described tooth form rolling tool, it is desirable that the non-processed part is formed in two teeth adjacent to the correction part.

  By adopting such a configuration, it is possible to more reliably prevent the tool from being damaged from the straightening portion, so that the tool life can be further improved.

  The tooth profile rolling tool described above is suitable for forming a helical gear on a workpiece.

  Since the non-machined part is provided at the tooth tip, there is a risk that the non-machined part will not mesh with the workpiece at the initial stage of rolling, but if the helical gear is rolled, the work and the tooth profile rolling tool are meshed. Can always be maintained. Therefore, one of the workpiece and the tooth profile rolling tool can be rotated and the other driven, and the workpiece and the tool can be reliably rotated synchronously.

  Moreover, the manufacturing method of the gear product which is another form of this invention made | formed in order to solve the said subject presses the process tooth of any one above-mentioned tooth profile rolling tool against a workpiece | work, and synchronizes with rotation of a workpiece | work. Then, the tooth profile rolling tool is moved to form a tooth profile on the workpiece.

  According to this gear product manufacturing method, since the tooth profile is formed using the above-described tooth profile rolling tool, the tool is formed while forming the internal teeth or external teeth to the desired product tooth depth and tooth tip shape on the workpiece. The lifetime can be improved.

  According to the manufacturing method of the tooth profile rolling tool and the gear product according to the present invention, as described above, the tool life is reduced by reducing the surface pressure applied to the rolling tool while forming the desired product tooth depth and tooth tip shape on the workpiece. Can be improved.

It is an external appearance perspective view of the tooth profile rolling tool concerning an embodiment. It is a figure which shows typically the shape of the processing tooth in a tooth profile rolling tool. It is a figure which shows typically the state which pressed the tooth profile rolling tool on the inner periphery of the workpiece | work. It is a figure which shows typically the state of rolling initial stage. It is a figure which shows typically the state in the middle of rolling. It is a figure which shows typically the state by which the process tooth was biting into the inner periphery of the workpiece | work and the tooth profile was formed in the work inner periphery whole region. It is a figure which shows typically the state of the escape part vicinity in the rolling final stage. It is a figure which shows typically the state of the correction part vicinity in the rolling final stage. It is an external appearance perspective view of the gear product which has an internal tooth. It is a figure which shows the mode in the case of rolling an external tooth to a workpiece | work. It is a figure which shows the mode in the case of rolling an external tooth to a workpiece | work.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying a method for manufacturing a tooth profile rolling tool and a gear product according to the present invention will be described below in detail with reference to the drawings.
First, the tooth profile rolling tool according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is an external perspective view showing a tooth profile rolling tool according to an embodiment. FIG. 2 is a diagram schematically showing the shape of a processing tooth in a tooth profile rolling tool.

  As shown in FIG. 1, the tooth profile rolling tool 10 according to the present embodiment is a gear-shaped metal tool provided with processing teeth 11 on the outer periphery. The tooth profile rolling tool 10 presses the processing teeth 11 against the workpiece, and while the tooth profile rolling tool 10 and the workpiece are rotated synchronously, the tooth profile rolling tool 10 is pushed into the workpiece, thereby forming the tooth profile on the workpiece. It is designed to be molded (transferred).

  As shown in FIG. 2, a tooth bottom portion 12 and a tooth tip portion 13 are formed on the processed tooth 11. And in the tooth bottom part 12, the escape part 12a which a workpiece | work does not contact at the time of tooth profile rolling is formed. However, only one tooth of the tooth bottom portion 12 is formed with a correction portion 12b that comes into contact with the workpiece in the finished dimension of the workpiece. That is, the shape of the correction part 12b is formed so that the tooth surface and tip of the workpiece can be mainly rolled into a desired shape, and the tooth bottom of the correction part 12b is more than the tooth bottom of the escape part 12a. Is also located outside the tool. That is, as shown in FIG. 2, the relationship between the root circle radius ra of the escape portion 12a and the root circle radius rb of the correction portion 12b is ra <rb. Note that the root circle radius ra of the relief portion 12a is the distance from the rotation center O of the tooth profile rolling tool 10 to the tooth bottom of the relief portion 12a, and the root circle radius rb of the correction portion 12b is the tooth profile rolling tool. This is the distance from the rotation center O of 10 to the tooth bottom of the correction part 12b.

  Here, in this Embodiment, although the correction | amendment part 12b is provided only for one tooth of the root part 12, it can also provide two or more teeth. In addition, the correction | amendment part 12b should just be provided with at least 1 tooth | gear, and what is necessary is just to determine the setting number of the correction | amendment part 12b suitably according to the specification etc. of the gear (tooth profile) to shape | mold.

  On the other hand, the tooth tip part 13 is formed with a processed part 13a with which a workpiece abuts during tooth profile rolling. However, the non-processed part 13b which a workpiece | work does not contact | abut is formed in 2 teeth adjacent to the correction | amendment part 12b, when the correction | amendment part 12b contacts a workpiece | work. That is, the shape of the processed portion 13a is formed so that the tooth base of the workpiece can be rolled into a desired shape, and the tooth tip of the processed portion 13a is more tool than the tooth tip of the non-machined portion 13b. Located on the outside. That is, as shown in FIG. 2, the tooth tip radius Ra of the processed portion 13a and the tooth tip radius Rb of the non-processed portion 13b satisfy Ra> Rb. Note that the tooth tip radius Ra of the processing portion 13a is the distance from the rotation center O of the tooth profile rolling tool 10 to the tooth tip of the processing portion 13a, and the tooth tip radius Rb of the non-processing portion 13b is tooth profile rolling. This is the distance from the rotation center O of the tool 10 to the tooth tip of the non-machined portion 13b.

  Here, in this embodiment, the non-processed part 13b is provided on both (two teeth) adjacent to the correction part 12b, but the non-processed part 13b is at least one tooth (only one tooth) adjacent to the correction part 12b. ). However, in this case, the non-processed portion 13b is preferably provided on the teeth on the front side in the tool movement (rotation) direction with respect to the correction portion 12b. For example, in FIG. 2, if the tooth profile rolling tool 10 is rotated clockwise, only the non-machined portion 13b located on the lower side in the drawing may be provided. This is because the stress acting on the tooth base of the processing tooth 11 during tooth profile rolling increases on the rear side in the tool rotation direction of the processing tooth 11. For this reason, it is considered that forming the non-processed portion 13b on the teeth on the front side in the tool rotation direction with respect to the correction portion 12b has a larger effect of reducing the amplitude of stress received by the root of the processed tooth 11. As a result, it is possible to reliably prevent the tooth profile rolling tool 10 from being damaged from the correction portion 12b.

  Then, the method (rolling method) which manufactures a gear product using the above-mentioned tooth profile rolling tool 10 is demonstrated, referring FIGS. Here, the case where the gear product 20 which has an internal helical gear as shown in FIG. 9 is manufactured is illustrated. FIG. 3 is a diagram schematically showing a state in which the tooth profile rolling tool is pressed against the inner periphery of the workpiece. FIG. 4 is a diagram schematically showing an initial state of rolling. FIG. 5 is a diagram schematically showing a state during rolling. FIG. 6 is a diagram schematically illustrating a state in which the processing teeth are engaged with the inner periphery of the workpiece and the tooth profile is formed over the entire inner periphery of the workpiece. FIG. 7 is a diagram schematically showing a state in the vicinity of the escape portion at the end of rolling. FIG. 8 is a diagram schematically showing a state in the vicinity of the correction portion at the end of rolling. 4, 5, 7, and 8, the tooth profile rolling tool 10 is hatched so that the tooth profile formed on the workpiece W can be easily understood.

  First, as shown in FIG. 3, the cylindrical workpiece W for rolling the internal teeth (helical gear in the present embodiment) is set in a device that rotatably holds the tooth-shaped rolling tool 10 of the workpiece W. It arrange | positions inside and is made to contact | abut to the internal peripheral surface of the workpiece | work W. FIG. Then, the tooth profile rolling tool 10 is rotationally driven, and the tooth profile rolling tool 10 is gradually pushed into the workpiece W in a state where the rotating machining teeth 11 are pressed against the inner surface of the workpiece W. That is, the tooth profile rolling tool 10 is slid to the workpiece W side so that the distance D between the rotation center Ow of the workpiece W and the rotation center O of the tooth profile rolling tool 10 is increased. Then, as shown in FIG. 4, the machining teeth 11 of the tooth profile rolling tool 10 are bitten into the inner peripheral surface of the workpiece W, and the portion engaging with the machining teeth 11 is recessed on the inner circumference of the workpiece W, and the remainder The meat escapes to the remaining part, and the part that is not engaged with the machining teeth 11 rises. At this time, the workpiece W is synchronously rotated following the rotational drive of the tooth profile rolling tool 10.

  Here, since the non-machined part 13b is provided in the tooth tip part 13 of the tooth profile rolling tool 10, the machined tooth 11 may not mesh with the workpiece W in the non-machined part 13b in the initial stage of rolling. In this embodiment, since the helical gear is rolled, it is possible to always maintain the state in which the workpiece W and the tooth profile rolling tool 10 are engaged with each other. Accordingly, the workpiece W can be reliably synchronized and driven in accordance with the rotational drive of the tooth profile rolling tool 10.

  Then, as shown in FIG. 5, as the pressing amount of the tooth profile rolling tool 10 into the inner peripheral surface of the workpiece W increases, the portion of the inner periphery of the workpiece W that is not engaged with the machining teeth 11 gradually rises. To go. At this time, as shown in FIG. 6, the tooth profile is formed over the entire inner circumference of the workpiece W.

  After that, when the tooth profile rolling tool 10 is pushed into the workpiece W while rotating the tooth profile rolling tool 10 at the final stage of rolling, the sliding of the tooth profile rolling tool 10 is stopped and only the rotational drive is performed. Thereby, in a state where the position of the tooth profile rolling tool 10 is fixed, the tooth profile rolling tool 10 and the workpiece W are rotated synchronously. At this time, since the relief part 12a is provided in the tooth bottom part 12 (other than the correction part 12b) on the tooth bottom side of the tooth profile rolling tool 10, the tooth tip formed on the workpiece W is formed as shown in FIG. I won't win. For this reason, the surface pressure (stress) which acts on the processing tooth 11 of the tooth profile rolling tool 10 can be lowered.

  Here, since the relief portion 12 a is provided in the tooth bottom portion 12 of the tooth profile rolling tool 10, the convex portion 25 remains on the tooth tip portion formed on the workpiece W. However, as shown in FIG. 8, the convex portion 25 is corrected by the correction portion 12b because the tooth profile rolling tool 10 and the workpiece W are rotating synchronously. As a result, the desired product toothpaste and tooth shape of the tooth tip are formed (transferred) on the workpiece W.

  Moreover, when the convex part 25 formed in the tooth tip part of the workpiece W is corrected, a large surface pressure acts on the processing teeth 11 adjacent to the correction part 12b. However, since the tooth profile rolling tool 10 is provided with the non-processed part 13b on the two teeth adjacent to the correction part 12b, when the convex part 25 is corrected by the correction part 12b, as shown in FIG. 8, the correction part 12b The tooth tip of the processing tooth 11 adjacent to the workpiece W does not hit the workpiece W. Thereby, also when correcting the convex part 25, the surface pressure which acts on the processing tooth | gear 11 can be lowered | hung, and the damage from the correction part 12b can be prevented.

  Then, after stopping the sliding of the tooth profile rolling tool 10, when the tooth profile rolling tool 10 is rotated by a predetermined number of rotations (or a predetermined time), the rotational driving of the tooth profile rolling tool 10 is stopped. Thereby, the tooth profile rolling to the workpiece | work W by the tooth profile rolling tool 10 is completed. Thereafter, when the tooth profile rolling tool 10 is separated from the workpiece W and the workpiece W is taken out of the apparatus, a gear product 20 having internal teeth (helical gear) 21 as shown in FIG. 9 is obtained.

  As described above in detail, according to the tooth profile rolling tool 10 according to the present embodiment, since the relief portion 12a where the workpiece W does not contact is formed on the tooth bottom portion 12, it acts on the machining teeth 11. The surface pressure can be lowered. Moreover, since the correction | amendment part 12b contact | abutted to the workpiece | work W with the finishing dimension of the workpiece | work W is formed in one tooth of the tooth root part 12, even if the convex part 25 is formed in the tooth | tip tip of the workpiece | work W, the correction | amendment part 12b Thus, the convex portion 25 is corrected, and the tooth profile having the desired tooth depth and the tip shape can be rolled onto the workpiece W. Further, in the tooth tip portion 13, the two teeth adjacent to the correction portion 12 b are provided with a non-working portion 13 b where the workpiece W does not contact when the correction portion 12 b contacts the workpiece W and corrects the tooth tip. Therefore, when correcting the convex part 25 of the tooth tip of the workpiece W by the correction part 12b, the surface pressure acting on the processing tooth 11 can be lowered. Accordingly, the tool life can be improved by lowering the surface pressure applied to the machining teeth 11 while forming the desired tooth depth and the tooth-shaped inner teeth 21 on the workpiece W.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the case where the inner teeth are formed (rolled) has been described. However, the tooth profile rolling tool 10 can be used not only for rolling inner teeth but also for rolling outer teeth. . When rolling the external teeth, as shown in FIG. 10, the tooth-shaped rolling tools 10 a and 10 b are arranged on the outer periphery of the work W so as to sandwich the work W. At this time, the rotation center Ow of the workpiece W is positioned on a line segment connecting the rotation centers Oa and Ob of the tooth profile rolling tools 10a and 10b. Then, the tooth profile rolling tools 10a and 10b are driven to rotate in synchronization with each other, and the tooth profile rolling tools 10a and 10b are slid in a direction to approach the workpiece W. If it does so, an external tooth will be shape | molded (transferred) to the workpiece | work W like the case where an internal tooth is rolled. In this case as well, the tool life can be improved by lowering the surface pressure applied to the processed teeth 11 while forming the desired tooth depth and the outer shape of the tooth tip on the workpiece W.

  Here, when rolling the external teeth, it is possible to use a rack provided with processing teeth in a straight line instead of the gear-shaped rolling tool as described above. In other words, as shown in FIG. 11, both the racks 30a and 30b are formed by forming the processing teeth 11 provided in a straight line, arranging the two racks 30a and 30b in parallel, and sandwiching the workpiece W therebetween. Is slid in the direction of the arrow, and the workpiece W is rotated about the rotation center Ow. If it does so, an external tooth will be shape | molded (transferred) to the workpiece | work W similarly to the case where it rolls with a gear-shaped rolling tool. Even with the rolling tool having such a shape, it is possible to improve the tool life by lowering the surface pressure applied to the processing tooth 11 while forming the desired tooth depth and the outer shape of the tooth tip on the workpiece W. it can.

  In the above-described embodiment, when rolling the internal teeth, the tooth profile rolling tool 10 is slid to increase the distance D between the rotation center Ow of the workpiece W and the rotation center O of the tooth profile rolling tool 10. Although the tooth profile rolling tool 10 is pushed into the workpiece W, the workpiece W may be slid to increase the center distance D and the workpiece W may be pushed into the tooth profile rolling tool 10.

  Furthermore, in the above-described embodiment, the case where the helical gear is rolled is illustrated, but the present invention can also be applied to the case where a spur gear other than the helical gear is rolled.

DESCRIPTION OF SYMBOLS 10 Tooth profile rolling tool 11 Process tooth 12 Tooth bottom part 12a Escape part 12b Straightening part 13 Tooth tip part 13a Processed part 13b Non-processed part 20 Gear product 21 Internal tooth 25 Convex part 30a, 30b Rack (tooth profile rolling tool)
D (Center-to-center) distance O, Oa, Ob Rotation center Ow (of tooth profile rolling tool) Rotation center Ra, Rb Tip circle radius ra, rb Bottom circle radius W Workpiece

Claims (7)

In a tooth profile rolling tool that forms a tooth profile by pressing a processed tooth having a root portion and a tooth tip portion against a workpiece,
The tooth bottom portion is formed with a relief portion where the workpiece does not contact, and at least one tooth is formed with a correction portion that contacts the workpiece with the finished dimension of the workpiece,
The tooth tip portion is formed with a processing portion that contacts the workpiece, and at least one tooth adjacent to the correction portion does not contact the workpiece when the correction portion contacts the workpiece. Tooth profile rolling tool characterized in that part is formed. In the tooth profile rolling tool according to claim 1,
A tooth profile rolling tool characterized by forming inner teeth on the inner periphery of a workpiece. In the tooth profile rolling tool according to claim 1,
A tooth profile rolling tool characterized in that external teeth are formed on the outer periphery of a workpiece. In any one of the tooth profile rolling tools according to claim 1,
When the non-processed part is formed on only one tooth adjacent to the correction part, the non-processed part is formed on a tooth on the front side in the tool movement direction with respect to the correction part. Tooth profile rolling tool. In any one of the tooth profile rolling tools according to claim 1,
The non-machined part is formed in two teeth adjacent to the orthodontic part. In any one of the tooth profile rolling tools according to claim 1,
Tooth profile rolling tool characterized by forming helical gear on workpiece. In a gear product manufacturing method of manufacturing a gear product by rolling,
A processing tooth of any one of the tooth profile rolling tools according to claim 1 is pressed against a workpiece, and the tooth profile rolling tool is moved in synchronization with the rotation of the workpiece to form a tooth profile on the workpiece. A method for manufacturing a gear product.

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