JP5877467B2 - Method of chamfering gear tooth profile - Google Patents

Description

  The present invention relates to a method for chamfering a tooth profile of a gear (work) formed by shaving, hobbing or forging. According to the method for chamfering a tooth profile of the present invention, the chamfering processing time can be shortened to about 1/2 as compared with a chamfering method for a tooth profile using a tooth profile shaping device using a conventional end mill device or a screw-shaped grindstone. Even if the workpiece material is a hard material, it has the advantage that it can be chamfered.

  When chamfering a gear, if there are scratches or turns on the tooth surface, noise or vibration will occur when the gears mesh with each other. The purpose is to prevent the turnout.

  Various tooth profile shaping devices are sold, and many patent documents have proposed a method for chamfering a tooth profile. For example, Japanese Patent Publication No. S32-8850 (Patent Document 1) gives rotation and feed to a screw file, while rotating the work gear (work) and chamfering the top of the tooth profile with the screw file. Then, the chamfering of the side surface portion is performed by engaging a screw file with the side surface portion of the tooth profile of the gear to be processed, and feeding it downward to some extent and rotating it. To chamfer the side surface of the opposite surface of the gear to be machined, attach the workpiece gear to the opposite side, engage the screw file with the tooth profile side surface of the gear to be machined, feed it downward to some extent, and rotate it to some extent. A method of processing is proposed.

  Japanese Patent Application Laid-Open No. 62-24912 (Patent Document 2) meshes a gear finishing tool and a gear to be machined (workpiece) and meshes a second gear with the gear to be machined. A method of finishing a tooth surface of the gear to be processed while driving and rotating a tool is proposed.

  Japanese Patent Laid-Open No. 3-104510 (Patent Document 3) has means for placing a gear to be shaped having reference holes at both ends in the axial direction so that the central axis of the gear to be shaped is positioned near the reference axis; One of a pair of conical centers arranged opposite to each other with the mounting means on the reference axis is configured to be movable in the reference axis direction, and the one conical center is close to the other conical center. The center axis of the gear to be shaped is moved by inserting the tip of the pair of conical centers into the corresponding reference holes and sandwiching the gear to be shaped between the pair of conical centers. Centering means for aligning the reference gear with the reference axis, gear rotation means for rotating the gear to be shaped around the reference axis, a cutter for contacting the edge of the gear to be shaped and grinding the edge, and Cutter means having a motor for rotating the cutter, Chamfering means attached to the utter moving means, sensor means for detecting the tooth tip of the gear to be shaped, and the cutter to the gear to be shaped based on the signal from the sensor means and the tooth profile data of the gear to be shaped. Means for controlling the operation of the gear rotating means and the cutter moving means so as to move along the edge while being in contact with the edge of the cutter, and the cutter of the chamfering means is formed in a rod shape. A gear tooth profile shaping device is proposed in which the cutter means is attached to the cutter moving means via a flexible support arm.

Further, Japanese Patent Laid-Open No. 7-1230 (Patent Document 4) discloses a burr raising means for inducing burr formed inwardly at an end portion of a loaded workpiece, and burr inclining for further raising the burr raised outward. And a burr removing means for removing the fallen burr. The gear-shaped teeth of the burr raising tool provided in the burr raising means are meshed with the tooth portion of the work and are slid in the direction of the tooth trace to After raising the burrs, the gear-shaped teeth of the burring tool provided in the burring device are engaged with the teeth of the workpiece in a posture in which the axis is inclined with respect to the workpiece, and then the burrs are removed. The present invention proposes a deburring method for a gear end characterized by rotating and removing a burr using a deburring tool provided.

  Further, this Patent Document 4) includes a cradle for receiving a workpiece, a burr raising tool for inwardly forming a burr formed at an end portion of the workpiece placed on the cradle, the burr raising tool and the workpiece. And a burr raising mechanism for holding the work placed on the cradle so as to be movable in a direction crossing the sliding direction. A gear end characterized in that the tool is provided with gear-shaped teeth that mesh with the tooth portion of the workpiece, and the workpiece is moved by the movement holding mechanism and the workpiece is burred while being engaged with the burr raising tool. A deburring device is proposed.

  Furthermore, JP 2010-184323 A (Patent Document 5) is a gear machining method for forming a tooth surface of a work gear cut out from a material, wherein the first shaving cutter is outside the shaving standard, A first shaving step for performing rough finish cutting of the tooth surface of the work gear, and a second shaving cutter within the shaving standard (engagement pressure angle of the first shaving cutter and the second shaving cutter), the work gear And a second shaving step for performing precision finish cutting of the tooth surface.

  On the other hand, Japanese Patent Application Laid-Open No. 5-269621 (Patent Document 6) discloses a gear chamfering device that rotates a workpiece gear held by a rotating device and chamfers the tooth profile corners on both sides of the gear with a flat grinding wheel. A grinder support device capable of supporting a grinder mounted with the above-mentioned flat grinding wheel in a central portion in a balance-like manner, and applying a grinding cutting force to the grindstone by a difference in rotational moment about a balance fulcrum on the left and right sides of the grinder, and a guide rail A grinder gear radial movement device that moves in the radial direction of the gear by the operation of the cylinder and makes the positioning of the grindstone with the stopper set by the stopper device, and movement of the gear radial movement device Grinder gear axial direction moving device that provides an axial direction movement guide on the table and moves the grinder by rotating the screw shaft, and the length direction A stopper device that sets a movable stopper position according to a chamfered gear diameter by moving a pair of left and right movable stoppers symmetrically with a screw shaft configured as a left and right reverse lead with a central portion as a boundary. A gear chamfering device is proposed which is provided as a pair of devices for upper and lower surfaces of a gear.

  Further, a gear chamfering device using an end mill device has also been put into practical use. Japanese Patent Application Laid-Open No. 10-94921 (Patent Document 7) discloses a work table for holding a gear material and both chamfers on both teeth of the gear material. A blade is attached to each swivel shaft having a different rotational direction to form a surface, and a half circumferential area of each blade is crossed with the shaft of the gear member determined by the angle of the chamfer surface. In a gear chamfering machine having a tool post for chamfering by abutting to the at least, a feed mechanism that reciprocates one of the tool rest or the work rest on the coordinate plane, and both stop points of the reciprocation. The gear chamfering machine is characterized in that the positional relationship of the tool rest or the work rest is set so that the operation quadrant between the swivel shafts of the respective cutters is switched to the adjacent quadrant.

Japanese Patent Publication No.32-8850 JP-A-62-24912 Japanese Patent Laid-Open No. 3-104510 JP-A-7-1230 JP 2010-184323 A JP-A-5-269621 JP-A-10-94921

  The chamfering method using the screw file described in Patent Document 1 changes the torsion angle between the workpiece and the tool, and chamfers the top (B) of the tooth profile of the gear to be processed and the side (A) of the tooth profile separately. Therefore, the chamfering time is about 1.5 times longer than the chamfering time using the milling device.

  The chamfering method described in Patent Documents 2, 3 and 5 can chamfer the tooth profile even if the gear material is a hard material, and the chamfering time can also be 2/3 of the method described in Patent Document 1. There are advantages you can do.

  The gear end deburring device described in Patent Document 4 has a complicated device structure. Therefore, it is necessary to make the structure of the gear tooth shaping apparatus more compact.

  The chamfering method using the end mill device of Patent Document 6 can chamfer the tooth profile even if the gear material is a hard material, and has a diameter of 91 mm, a thickness of 7.5 mm, a number of tooth profiles of 46, and a pitch of 6.35. There is an advantage that the chamfering time of the tooth profile of the gear (work) can be performed in about 1 minute. However, the gear manufacturing and processing industry requires chamfering with a shaping time of 30 seconds, which is about half of this time.

  The object of the present invention is to propose a chamfering method that can simultaneously perform deburring (chamfering) processing of the top (B) and side surface (A) of the tooth profile described in Patent Document 1, for example, a diameter of 91 mm, a thickness of 7.5 mm, The present invention provides a tooth profile shaping method using a screw-shaped grindstone (tool) capable of performing the chamfering processing time of the tooth profile of the gear (workpiece) having a tooth number of 46 and a pitch of 6.35 in about 30 seconds.

According to the first aspect of the present invention, the center line passing through the rotational axis (gc) of the threaded grindstone (g) is fixed to the rotating shaft and rotated. axis (gc) and chamfered as outer edge upper part straight and sandwich angles connecting the point of contact (theta) is the processed gear so that 35 to 60 degrees of the work gear (w) ( w) and the threaded grinding wheel (g) are brought into contact with each other, and the tooth profile side surface (A1) of the upper surface of the processed gear (w) by the rotation of the threaded grinding wheel (g) and the rotation of the processing gear (w). , A2) and chamfering of the tooth bottom (B1) at the same time at the grindstone pressure angle (α) α = the angle θ ± (3-7) ,
After separating the work gear (w) and the threaded grindstone (g), the work gear (w) is turned upside down and fixed to the rotary shaft,
Then, the rotating with respect to the work gear (w), the angle (theta) was that abuts said and said threaded grinding wheel and the workpiece gear (w) (g) so that 35 to 60 degrees , rotation and simultaneously grinding the chamfering of the workpiece gear (w) of the upper surface of the tooth sides (A1, A2) and tooth gap (B1) by the rotation of the work gear (w) of the screw-shaped grindstone (g) Pressure angle (α) α = the angle of θ ± (3-7) ,
A method for chamfering a tooth profile of a gear characterized by the above is provided.

3 steps in the gear chamfering method described in Patent Document 1 by specifying the angle (θ) at which the work gear (workpiece) and the screw- shaped grindstone (tool) shown in FIG. Among the chamfering processes, the chamfering process of the tooth crest (B section) is no longer necessary. In addition, the chamfering time of the tooth profile of the gear to be processed could be reduced to about ½ of the chamfering time using the conventional end mill device.

FIG. 1 is a process diagram of a tooth profile chamfering operation. FIG. 2 is a partial view showing a state in which the tooth shape of the gear to be processed and the threaded grindstone are in contact, FIG. 2a is a perspective view, and FIG. 2b is a plan view. FIG. 3 is a diagram showing the grindstone pressure angle of the thread-shaped grindstone during tooth profile shaping. FIG. 4 is an enlarged partial view of the tooth profile after chamfering.

As shown in FIG. 1, the method for chamfering the tooth profile of the gear of the present invention includes (1). A center line passing through the rotational axis (gc) of the threaded grindstone (g) and the rotational axis (gc) are chamfered with respect to the rotating gear to be machined (w) fixed to the rotational axis. the work gear straight and sandwich angles connecting the point of contact on the outer periphery upper portion of the (w) (θ) the processed gear are formed so that 35 to 60 degrees (w) and the screw-like grindstone (g) And the tooth- shaped side surfaces (A1, A2) and the tooth bottom (B1) of the upper surface of the processed gear (w) by the rotation of the screw-shaped grindstone (g) and the processed gear (w ). Surface grinding process in which chamfering is simultaneously performed at a grinding wheel pressure angle (α) α = the angle of θ ± (3-7) ,
(2). A reversing and reversing step of fixing the work gear (w) upside down and fixing it to the rotating shaft after separating the work gear (w) and the thread-like grindstone (g);
(3). Rotation to have the relative workpiece gear (w), the angle (theta) is brought into contact said said threaded grinding wheel and the workpiece gear (w) (g) so that 35 to 60 degrees, the Grinding wheel pressure angle at the same time chamfering the tooth profile side surface (A1, A2) and tooth bottom (B1) of the upper surface of the work gear (w) by the rotation of the threaded grindstone (g) and the work gear (w). (Α) α = back surface grinding step performed at an angle of θ ± (3-7) ,
It is done through.

  FIG. 2 is a partial view showing a state in which the tooth profile of the gear w to be machined and the screw-shaped grindstone g are in contact with each other when the tooth profile is chamfered. gc represents the rotational axis of the threaded grindstone g.

FIG. 2 is a partial view showing a state in which the tooth profile of the gear w to be machined and the screw-shaped grindstone g are in contact with each other when the tooth profile is chamfered.

FIG. 3 is a diagram showing the grindstone pressure angle α of the thread-shaped grindstone g during tooth profile shaping. w _c represents the rotational axis of the gear w to be processed.

The angle of the screw-like grindstone g and the work gear w contacts θ is tooth profile of the work gear w, number of teeth, the thickness depends on the number of pitches. In an embodiment, when angles θ of 50 degrees, the grinding pressure angle α when chamfering is about 47.5 degrees. When the bevel angle 45 degrees aim of threaded grinding wheel relative to the workpiece, angles θ is 53.5 to 54.5 degrees, the grinding pressure angle α is optimum from 46.5 to 47.5 degrees.

In a strict sense in the case of chamfering by threaded grinding wheel, the number of teeth of the work gear w, the pressure angle (alpha), the threaded grinding wheel g is a need for module corresponding to them if Kaware the Angle (theta) and the like However, as described in paragraph 0002, the chamfering process simply needs to drop the corners such as the outer periphery and the side surface of the tooth profile, so prepare a threaded grindstone for each module of each gear w to be processed. put it, the angle of (theta) worker within the 35 to 60 ° and the work gear w and screw grinding wheel g during chamfering contacts can be found. When the bevel angle 45 degrees aim of threaded grinding wheel relative to the workpiece, the angle of θ is 53.5 to 54.5 degrees, the grinding pressure angle α is optimum from 46.5 to 47.5 degrees. Pressure angle of the workpiece gear w and screw grinding wheel g during chamfering (alpha) can be found in an angle within plus or minus (±) 3 to 7 degrees of the angle of (theta).

Example 1
As the work gear w, a sintered metal work gear having a diameter of 91 mm, a thickness of 7.5 mm, an involute tooth shape of 46, and a pitch of 6.35 was used.

The threaded grindstone (tool) g rotating at 1,500- ^min abutting on the outer peripheral edge of the rotating gear w to be rotated with respect to the workpiece gear w rotating at 32.61- ^min (rpm). the angle of contact with the outer peripheral edge (theta) is 50 degrees, the upper surface of the work gear and said abut with said threaded grinding wheel and the workpiece gear as grinding wheel pressure angle (alpha) is 47.5 degrees Simultaneous chamfering of the right side surface (A1), left side surface (A2) and tooth bottom (B1) of the tooth profile was performed (surface grinding step). The tooth profile side surface after chamfering of the gear to be processed is shown in FIG. It is understood that the screw marks of the threaded grindstone g are left on the chamfered tooth profile portions (side surfaces A1, A2 and tooth bottom B1).

After finishing the surface grinding step, the work gear w is retracted to separate the work gear w and the screw-shaped grindstone g, and then the work gear w is fixed to the rotating shaft with the upper surface and the lower surface reversed. (Evacuation reversal process).

After finishing the reversing and reversing step, the work gear w rotating at 32.61- ^min is advanced and brought into contact with the threaded grindstone g, and then rotated at 32.61- ^min. The angle (θ) of the threaded grindstone (tool) g rotating at 1,500- ^min that contacts the upper peripheral edge of the rotating gear w to be processed (work) w is 50 degrees, The processed gear and the threaded grindstone are brought into contact with each other so that the angle (α) is 47.5 degrees, and the right side surface (A1), the left side surface (A2) of the tooth shape on the upper surface of the processed gear and the tooth shape Simultaneous chamfering of the tooth bottom (B1) was performed (back grinding process).

  The chamfering time for one workpiece gear was 28 seconds.

  When the chamfered gears were meshed with each other and rotated, the noise was small and the burr did not fall further. Since one gear tooth profile root (B1) and the other gear tooth profile tooth tip (B2) of the meshing gear do not directly contact each other, the tooth profile tooth tip (B2) may or may not be chamfered. Good.

  The chamfering time of 28 seconds is equivalent to 1/2 of 56 seconds of the chamfering time of a single workpiece gear w to be processed by a conventional end mill.

w Workpiece gear (workpiece)
g Threaded grinding wheel (tool)
θ Contact angle between the gear to be machined and the threaded grinding wheel α Grinding wheel pressure angle A1 Right side of tooth profile A2 Left side of tooth profile B1 Tooth root B2 Tooth tip of tooth profile

Claims (1)

A center line passing through the rotational axis (gc) of the threaded grindstone (g) and the rotational axis (gc) are chamfered with respect to the rotating gear to be machined (w) fixed to the rotational axis. the work gear straight and sandwich angles connecting the point of contact on the outer periphery upper portion of the (w) (θ) the processed gear are formed so that 35 to 60 degrees (w) and the screw-like grindstone (g) And the tooth- shaped side surfaces (A1, A2) and the tooth bottom (B1) of the upper surface of the processed gear (w) by the rotation of the screw-shaped grindstone (g) and the processed gear (w ). After performing chamfering simultaneously at the grinding wheel pressure angle (α) α = the angle of θ ± (3-7) ,
After separating the work gear (w) and the threaded grindstone (g), the work gear (w) is turned upside down and fixed to the rotary shaft,
Then, the rotating with respect to the work gear (w), the angle (theta) was that abuts said and said threaded grinding wheel and the workpiece gear (w) (g) so that 35 to 60 degrees , rotation and simultaneously grinding the chamfering of the workpiece gear (w) of the upper surface of the tooth sides (A1, A2) and tooth gap (B1) by the rotation of the work gear (w) of the screw-shaped grindstone (g) Pressure angle (α) α = the angle of θ ± (3-7) ,
A method for chamfering a tooth profile of a gear.