JP4957985B2 - Centerless gear wrapping machine - Google Patents

Description

  The present invention relates to a centerless gear wrapping method including a work gear that does not fix a central shaft, two lap tool gears that sandwich the work gear, and a guide gear that prevents the work gear from falling off and provides stable feed.

  For gear lapping, two specific gear pairs are meshed and rotated while supplying lapping fluid to finish the tooth surfaces of both gears, and the lapping tool gear is meshed with the workpiece gear and lapping is performed. Although there is a method of rotating while supplying liquid and finishing only the tooth surface of the gear to be processed, the present invention belongs to the latter, and a finishing method for a general purpose spur gear and a helical gear that does not specify a counter gear The gear train is rotated while supplying a lapping liquid that is a mixture of lapping abrasive grains and lapping oil to the meshing point of the gear to be machined and lapping gear, and the gear accuracy such as tooth surface roughness and tooth profile accuracy is improved. Basic.

  In the above lapping, the latter lapping method that does not specify the counter gear is highly versatile and has a short machining time, so it is suitable for mass production.However, it takes a lot of time to attach and remove the gear to be machined against the net machining time. In short, there is a problem that this greatly hinders improvement in production efficiency.

  Further, in the conventional lapping method that does not specify the counter gear, only one tooth surface of the gear to be processed is processed with respect to one-way rotation of the lap driving gear. There has been a problem that the gear to be processed must be replaced in the reverse direction or the lap gear must be rotated in the reverse direction.

Helical gears are a type of screw gear, so that axial thrust acts on the workpiece gear by rotation, and in centerless wrapping where the workpiece gear is not fixed to the shaft, rotation of the lap gear causes the workpiece gear to move in the axial direction. There is a problem popping out.

  As a method of shortening the work of attaching and removing the work gear, a centerless wrapping method that does not fix the work gear to the shaft is effective, and a tool such as a spanner is not required for attaching and removing the work gear, Since the gear to be processed can be easily replaced, the replacement time can be greatly shortened, and the automation of attachment / detachment is extremely easy.

  If the work gear is sandwiched between two lap gears and meshed, one lap gear is driven, the other lap gear is braked and a machining load is applied, the driven lap gear and the brake wrap gear respectively Since each tooth surface of the machined gear is machined, both tooth surfaces can be machined at once, and the net machining time is halved.

  In order to give the machined gear and the lap gear a sliding movement in the direction of the tooth trace and to uniformize the removal amount of the entire tooth profile of the machined gear, if the machined gear is a spur gear, When using helical gears with the same degree of helix angle in the same direction and the gear to be machined is a helical gear, the two lap gears are either spur gears or machined depending on the helix angle. A helical gear with an appropriate amount of helix angle in the same helix direction as the gear is used, and the gear to be machined and the lap gear are engaged with each other by intersecting them by an angle corresponding to the sum of the helix angles of both. If the work gear is a spur gear, a spur gear is used. If the work gear is a helical gear, a reverse-twisted helical gear having the same torsion angle is used. Also in the case of

  For the axial thrust of the work gear generated by the rotation of the helical gear shown above, a U-shaped work gear holding device having a rotating disk inside is provided to control the feed speed. By adopting the U-shaped workpiece gear holding device, it can cope with any direction of thrust. Further, since the rotating disk supports and holds the wide side surface of the gear to be processed with a slight gap, the inclination of the gear to be processed that is not fixed to the shaft is well suppressed, which leads to an improvement in processing accuracy.

  The object of the present invention is achieved by the following means.

  (1) If a work gear is sandwiched between two lap gears and meshed, the work gear can be rotated without being fixed to the shaft, and a lap liquid in which abrasive grains and lap oil are mixed at the meshing point The centerless wrapping without fixing the gear to be processed to the shaft can be realized.

  (2) In the above gear train, if one lap gear is rotated and driven, and the other lap gear is braked to apply a machining load, each tooth surface of the workpiece gear is machined by each lap gear. It is possible to finish both tooth surfaces at once.

  (3) When the work gear is a spur gear, use helical gears having an appropriate size and the same helix angle as the two lap gears, and when the work gear is a helical gear, Depending on the size of the torsion angle, if a spur gear or a helical gear with an appropriate amount of torsion angle in the same direction as the gear to be machined is used, an axial sliding movement between the gear tooth surface of the gear to be machined And uniform processing of the entire tooth surface can be realized.

  (4) When the gear to be machined that is not fixed to the shaft is sandwiched between two lap gears and meshed with each other and the drive lap gear is rotated, the gear to be machined pops out in the direction perpendicular to the axis due to the rotational force. A guide gear is provided to prevent the workpiece gear from falling off. The guide gear is a spur gear when the workpiece gear is a spur gear, and the same size and a reverse twist angle when it is a helical gear. Use helical gears.

  (5) A helical gear generates a thrust in the axial direction due to its torsion when it is rotated, and the gear to be machined tends to jump out in the axial direction in centerless wrapping that does not fix the machined gear to the shaft. If the speed is controlled by a feeding device having a U-shaped work gear holding device having two rotating disks, the required feeding speed can be obtained, and the workpiece can be processed between the two rotating disks. By supporting the gear with a very slight gap, it is possible to prevent the gear to be machined from being tilted and not to be fixed to the shaft, thereby realizing high-precision machining.

  According to the present invention described above, the following effects can be obtained for each claim.

  According to the first aspect of the present invention, the gear to be processed is sandwiched between two lap gears and one guide gear, meshed and rotated, and a lap liquid in which fine abrasive grains and an oil agent are mixed is supplied to the meshing point. This makes it possible to achieve centerless lapping without fixing the workpiece gear to the shaft, and it can be easily replaced in a short time without the need for tools to attach and remove the workpiece gear, significantly improving production efficiency. realizable.

  According to the second aspect of the present invention, one of the two lap gears meshed with the gear to be machined is fixed to a drive shaft that is rotated by an electric motor, and the other is fixed to a brake shaft, so that an appropriate braking force can be applied. For example, the same processing load can be applied to both tooth surfaces, and each lap gear processes one tooth surface of the gear to be processed, so both tooth surfaces are processed at one time, and the net processing time can be halved.

  According to the third aspect of the present invention, if the processed gear is held by giving a very small clearance to the rotating disk installed in the U-shaped processed gear holding device, the processed gear being processed is obtained. In addition to being able to improve the machining accuracy in the direction of the tooth trace, it can be applied to any direction of axial thrust generated by the twist direction of the lap gear or workpiece gear. it can.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, an outline of a centerless wrapping machine for wrapping a spur gear or a helical gear will be described first, followed by wrapping of a spur gear or a helical gear using a centerless wrapping machine. A method will be described.

  Hereinafter, the outline of the lapping machine will be described with reference to the assembly drawing of the lapping machine shown in FIG. 1, and the lapping method will be described with reference to detailed views of each part shown in FIGS.

Structure of heartless lapping machine

  FIG. 1 is a diagram showing a schematic configuration of a centerless lapping machine according to the present invention.

  If the workpiece gear (1), which is a spur gear or a helical gear to be lapped, is sandwiched between the two lap gears (2) and (3) and meshed with each other, the workpiece gear becomes a shaft. Can be held without the so-called heart.

  In the meshing of the work gear (1) and the lap gears (2) and (3), in order to exert a lapping effect on the whole tooth profile by giving a sliding motion not only in the tooth profile direction but also in the tooth trace direction, the work gear (1 ) Is a spur gear, lap gears (2), (3) are helical gears, and if the gear to be machined (1) is a helical gear, wrap gears (2), (3) are A helical gear having an appropriate helix angle in the same helix direction as the spur gear or the work gear (1) is used. Therefore, the rotation axis of the wrap gears (2) and (3) corresponds to the sum of the torsion angles of both gears with respect to the rotation axis of the gear (1) to be machined (because it has no center and therefore becomes a virtual center axis). It will cross only the angle.

  However, if the driving side lap gear (2) is rotated as it is, the workpiece gear (1) tends to be pushed out in any direction perpendicular to the axis depending on the direction of rotation. Therefore, a guide gear (4) for preventing the workpiece gear (1) from popping out and guiding the feed movement is provided.

  When the work gear (1) is a spur gear, the guide gear (4) is arranged so that the meshing state does not change even if the work gear (1) moves in the axial direction by the feed movement. ) Also uses a spur gear, and when the gear to be machined (1) is a helical gear, the guide gear (4) is a helical gear with a reverse twist having the same helix angle as the gear to be machined (1). Is used. Note that it is advantageous to use a soft material such as nylon resin for both the lap gear and the guide gear because the contact becomes soft and the tooth surface of the gear to be processed is more mirror finished.

  When the helical gear is rotated, thrust acts in the axial direction in accordance with the torsion angle of the teeth, so that the workpiece gear (1) not fixed on the shaft tends to be pushed out in the axial direction. Therefore, the rotating disks (7-1) and (7-2) provided inside the U-shaped machined gear holding device (6) shown in FIG. If it is supported in a wide range and is reciprocated by the feed direction switching device (9) at an appropriate speed by the feed speed adjusting motor (8) by a length corresponding to the tooth width of the gear to be machined (1), The entire tooth width of the processed gear (1) can be uniformly finished.

  The other end of the rotating shaft of the brake wrap gear (3) is provided with a brake device (10) for applying a machining load as shown in FIG. 21) and the detector (22), and the tightening force of the brake pad (20) is automatically adjusted by the load adjusting motor (23) and the gear train (24).

  As shown in FIG. 6, fine abrasive grains and an oil agent are respectively applied to the meshing points of the drive lap gear (2) and the workpiece gear (1) and the meshing points of the brake lap gear (3) and the workpiece gear (1). There is a lap liquid supply pipe (27-1), (27-2) for supplying the mixed lap liquid after adjusting the flow rate to an appropriate flow rate using the flow rate adjusting valves (28-1), (28-2). is doing.

Machining with a heartless lapping machine

  The processing principle and processing method of the centerless lapping machine of the present invention will be described with reference to FIGS. 1 and 2 to 6.

  When the variable speed drive motor (5) shown in FIG. 1 is rotated, the drive lap gear (2) fixed to the drive shaft connected thereto is rotated, and the drive lap gear (2) has a work gear (1 ) Is engaged with an angle corresponding to the sum of the torsion angles of the two gears, and the brake wrap gear (3) is engaged with the workpiece gear (1) at an angle similar to the above. The rotation is transmitted (see FIG. 2).

  A brake (10) is provided at the other end of the brake shaft to which the brake wrap gear (3) is fixed, and the braking force can be adjusted (see FIG. 5). Due to this braking force, the same amount of pressure is applied between the tooth flank of the drive wrap gear (2) and the gear to be machined (1) and between the tooth lap of the brake lap gear (3) and the gear to be machined (1). Is generated and becomes a lapping load (see FIG. 3).

  The drive wrap gear (2) and the work gear (1), and the brake wrap gear (3) and the work gear (1) mesh with each other with the sum of the torsion angles of the two gears. When 2) is rotated, in addition to the meshing slip in the tooth profile direction, a slip also occurs in the tooth trace direction, which becomes a machining motion. If an appropriate amount of lap liquid is supplied from the lap liquid supply apparatus shown in FIG. 6, a polishing action is generated.

  Due to the rotation of the drive wrap gear (2), the gear to be machined (1) tends to be pushed out in the direction perpendicular to the axis. Therefore, a guide gear (4) is provided to support it so as not to jump out (see FIG. 3). The guide gear (4) securely holds the entire tooth width of the gear to be machined (1). Therefore, when the gear to be machined (1) is a spur gear, it is a spur gear, and when it is a helical gear, the gear to be machined ( Helical gears having the same torsion angle in the opposite direction to 1) are used.

  When the helical gear is engaged, thrust is generated in the axial direction. It has a feed direction switching device (9) that supports the thrust force and causes the workpiece gear (1) to reciprocate in the axial direction at an appropriate feed speed. The feed amount needs to be reciprocated by the same length as the tooth width of the workpiece gear (1) in order to uniformly process the entire tooth width of the workpiece gear (1).

  Since the spur gear and the helical gear mesh with each other or the helical gears with the same torsion are theoretically in line contact, the tooth surfaces of the drive lap gear (2) and brake lap gear (3) are very The narrow region contacts and meshes with the gear tooth surface to be machined, lapping is performed, and the other tooth surfaces are not involved in machining at all. Therefore, since both lap gears (2) and (3) are worn only in a narrow range, the lap gears (2) and (3) are shifted by an appropriate amount in the axial direction so that both lap gears (2) , (3) is provided with a shift function for effectively utilizing the entire tooth width region and extending the life of both lap gears (2), (3).

  When it is desired to finish the tooth surface finish of the gear to be machined (1) more smoothly, first, rough lapping using coarse abrasive grains is performed, and then final lapping using fine abrasive grains is performed. In order to prevent the abrasive grains from mixing, the drive lap gear (2) and the brake lap gear (3) are replaced with those for finishing. Reverse twist to improve machining efficiency. In order to achieve this, the drive wrap gear (2) and the brake wrap gear (3) with respect to the gear (1) to be machined are tilted in the opposite direction to that during rough wrapping.

  When the workpiece gear (1) is inserted between the two rotating disks (7-1), (7-2) of the U-shaped workpiece gear holding device (6) from the direction perpendicular to the axis, the workpiece gear Since the tooth tip of (1) and the tooth tips of the drive wrap gear (2) and brake wrap gear (3) may interfere with each other, the drive lap may be inserted when the gear (1) is inserted. The gear (2) is slowly inserted while being driven at a low speed (see FIG. 4). Therefore, the drive motor (5) has a variable rotation function that rotates at a low speed when the work gear (1) is inserted, and performs lapping at a high speed after the insertion is completed.

Industrial applicability

  The centerless gear lapping machine of the present invention is a general purpose spur gear and helical gear lapping finish machine that does not specify a counter gear, unlike the conventional co-rubbing method that specifies a counter gear. Very wide.

  This machine has a machining time as short as several tens of seconds, and can be easily machined even with carburized and hardened gears. The machined gears increase their durability and reduce operating noise. It is most effective when used in mass production sites such as the automobile industry.

  Utilizing the effect of reducing the operating noise of the gear machined by this machine, the effect can be expected by utilizing the pinion for the gear reducer and the gear used in OA equipment, which is particularly required to be quiet.

It is the schematic which shows the structure of a centerless gear lapping machine. It is a figure which shows the positional relationship and meshing state of a to-be-processed gear, a drive lap gear, a brake lap gear, and a guide gear. It is a figure which shows the direction of the force (processing load) which acts on the tooth surface of a to-be-processed gear. It is a figure which shows the brake mechanism which gives a process load. It is a figure which shows a U-shaped to-be-processed gear holding apparatus. It is a figure which shows a wrap liquid supply apparatus.

Explanation of symbols

1: Workpiece gear 2: Drive wrap gear 3: Brake wrap gear 4: Guide gear 5: Drive motor 6: U-shaped work gear holding device 7-1, 7-2: Rotating disc 8: Feed speed Adjustment motor 9: Feed direction switching device 10: Brake device 11: Drive shaft bearing 12: Brake shaft bearing 13-1, 13-2: Guide gear shaft bearing 14-1, 14-2: Brake shaft bearing 15: Drive shaft Joint 16: Brake shaft joint 17: Column width adjustment screw 18: Column width adjustment handle 19-1: Drive shaft support column 19-2: Brake shaft support column 20: Brake pad 21: Strain gauge 22: Strain detector 23: Load adjusting motor 24: gear train 25: lap liquid tank 26: lap liquid agitator 27-1, 27-2: lap liquid supply pipe 28-1, 28-2: lap liquid flow rate adjusting valve

Claims (3)

In a gear wrapping device that supplies a lapping liquid in which minute abrasive grains and oil are mixed at an appropriate ratio to the meshing point between the work gear and the lapping gear and finish the tooth surface with high accuracy, the work gear that is not fixed to the shaft is A centerless wrapping apparatus characterized in that it is processed by being sandwiched between a total of three gears, two lap gears and one guide gear. One of the two lap gears is fixed to the drive shaft, is rotated by an electric motor or the like, the rotation is transmitted to the work gear meshing with the lap gear, and the other lap gear meshes with the work gear. The gear wrapping according to claim 1, wherein both tooth surfaces of the gear to be machined can be finished at a time by transmitting rotation to the latter and applying a machining load to the latter lap gear shaft using a brake device. Equipment . The gear to be machined that is not fixed to the shaft does not require tooth alignment from the direction perpendicular to the axis in the U-shaped machined gear holding device provided between the two lap gears, and a tool is used. The gear wrapping device according to claim 1, wherein the gear wrapping device can be easily attached and detached without any problem.

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