JP2017087329A - Gear polishing method using gear polishing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear polishing method using a gear polishing body that is able to prevent gear teeth from entering between adjacent polishing sheets during a gear polishing operation.SOLUTION: In a gear polishing method using a gear polishing body 4 with a helical polishing part 4a, the helical polishing part 4a has: a first thread face 11 in which, during rotary motion in one direction around a rotation axis S, the teeth 5a of a gear 5 slide while relatively moving so as to descend a level difference between polishing sheets 6A, 6B overlapping and adjacent to each other; and second thread face 12 in which the teeth 5a of the gear 5 slide while relatively moving so as to ascend the level difference between polishing sheets 6A, 6B overlapping and adjacent to each other. Gear faces are polished in such a manner that while the helical polishing part 4a is rotated in the one direction around the rotation axis S, rotation torque for pressing the teeth 5a of the gear 5 against the first thread face 11 is applied to the gear 5.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a gear polishing method for polishing a tooth surface of a gear by bringing a screw-like polishing function portion into contact with the teeth of the gear, and in particular, for a gear configured by overlapping a plurality of flexible polishing sheets. The present invention relates to a gear polishing method using a polishing body.

  2. Description of the Related Art In recent years, in the automobile field, where emphasis is placed on habitability and fuel consumption, it is increasingly required to improve the processing accuracy of gears used in transmissions and the like in order to improve tooth surface strength and reduce fuel consumption.

2. Description of the Related Art Conventionally, for the purpose of improving the processing accuracy of a gear, there is one in which a gear and a screw-shaped grindstone are rotated with each other in a meshed state, and a tooth surface of the gear is generated and ground (Patent Document 1). reference).
As the above-mentioned thread-like grindstone, for example, a thread-like grinding surface is formed over the entire surface in the axial direction at a precise pitch on the surface of the grindstone base material, and, for example, CBN abrasive grains are electrically connected to the grinding surface via a plating layer. There are things that you wear.

  However, in the above-mentioned threaded grinding wheel, in order to grind the gear tooth surface with high accuracy, the threaded grinding wheel itself must be formed with high precision according to the shape of the gear teeth. Is required and cannot be easily manufactured. Also, as the use progresses, the surface of the threaded grindstone itself is also shaved, so in order to maintain the processing accuracy, it is necessary to sometimes perform shaping work called dressing, and a dedicated machine for performing dressing is necessary. In addition, there is a problem that an additional time for dressing is required separately from the grinding work, resulting in an increase in incidental facilities and a deterioration in production efficiency.

  Therefore, a gear polishing body that can be easily manufactured and can polish the gear tooth surface with high accuracy without requiring special shaping work such as dressing has been proposed (see Patent Document 2).

JP 2013-18117 A Japanese Patent No. 5450870

  The gear polishing body according to Patent Document 2 described above has a screw-like polishing portion that can rotate about the rotation axis and meshes with the teeth of the gear that is the object to be polished. A plurality of flexible abrasive sheets having a bulging portion that bulges radially outward from a virtual circle having a root diameter of a thread-like polishing portion as a diameter. In addition, a thread-like polishing portion is formed by overlapping the polishing sheets in the rotation axis direction while shifting the bulging portions of these polishing sheets around the rotation axis.

Here, as shown in FIG. 4 showing one side portion of the thread-shaped portion, the thread-shaped polishing portion of the gear polishing body has _one direction around the rotation axis S1 of the thread-shaped polishing portion 4a ( In the case of the rotational movement in the direction of the arrow R in FIG. 4, the first screw is in sliding contact with the teeth 5a of the gear 5 moving relative to each other so as to descend the steps of the adjacent polishing sheets 6A and 6B that are superposed on each other. As shown in FIG. 5 showing the crest surface 11 and the other side portion of the thread shape portion, the teeth 5a of the gear 5 are relatively moved so as to go up the steps of the adjacent polishing sheets 6A and 6B overlapped with each other. The second thread surface 12 is in sliding contact with the second thread surface 12.

By the way, as shown in FIG. 5, the tooth 5a of the gear 5 is moved to the second thread surface 12 while rotating the threaded polishing portion 4a in _one direction around the rotation axis S1 (in the direction of arrow R in FIG. 5). When the tooth surface of the gear 5 is polished by pressing against the step, the polishing sheet 6A on the front side over the step where the tooth 5a of the gear 5 contacts is over the step before passing over the step in the adjacent polishing sheets 6A, 6B overlapped with each other. The teeth 5a of the gear 5 are moved relative to the second thread surface 12 in the direction in which the teeth 5a of the gear 5 bite into the rear side of the polishing sheet 6B beyond the step where the teeth 5a of the gear 5 come into contact later. A pressing force that pulls the polishing sheet 6A on the front side over the step away from the polishing sheet 6B on the rear side over the step is applied to the polishing sheet 6A on the front side over the step so that the polishing sheets 6A and 6B are pulled apart. A polishing operation for polishing the surface 5a is performed.
For this reason, during the polishing operation of the gear 5, there is a possibility that the teeth 5a of the gear 5 may bite between the adjacent polishing sheets 6A and 6B, which may hinder the polishing operation of the gear 5. There is a point.

  The present invention has been made in view of the above-described problems, and for gears that can reliably prevent the gear teeth from biting between adjacent polishing sheets during the gear polishing operation. An object of the present invention is to provide a gear polishing method using a polishing body.

In order to achieve the above object, a gear polishing method using a gear polishing body according to the present invention includes:
A gear polishing body that has a thread-like polishing portion that is capable of rotating around a rotation axis and meshes with a tooth of a gear to be polished, and that polishes the tooth surface of the gear by the rotational movement of the screw-like polishing portion. A plurality of flexible abrasive sheets having bulges that bulge radially outward from a virtual circle whose diameter is the valley diameter of the thread-like abrasive part. A gear polishing method using a gear polishing body formed by forming the thread-like polishing portion by overlapping the polishing sheets in the rotation axis direction while being shifted from each other around,
The thread-like polishing portion is relatively positioned so that the teeth of the gears go down the steps of the adjacent abrasive sheets that are overlapped with each other when the screw-like polishing portion rotates in one direction around the rotation axis. A first screw thread surface that is in sliding contact while moving, and a second screw thread surface that is in sliding contact while relatively moving so that the teeth of the gears rise over the steps of the adjacent abrasive sheets that are superimposed on each other. Then, while rotating the thread-like polishing portion in one direction around the rotation axis, a rotational torque for pressing the gear teeth against the first thread surface is applied to the gear to polish the gear teeth. It is characterized by doing.

  According to the present invention, the polishing sheet on the front side where the gear teeth are in contact with each other before the step between the adjacent abrasive sheets superimposed on each other and the back side on which the gear teeth are in contact with each other after the step is exceeded The gear teeth are moved relative to the first thread surface in the direction opposite to the direction in which the gear teeth bite between the polishing sheet and the polishing sheet on the front side over the step is changed to the polishing sheet on the back side over the step. A pressing force is sequentially applied to the adjacent abrasive sheets superimposed on each other as the gear teeth move relative to the first thread surface, and the gear tooth surfaces are polished while the abrasive sheets are in close contact with each other. Therefore, it is possible to reliably prevent the gear teeth from biting between the adjacent polishing sheets during the gear polishing operation.

FIG. 1 is a perspective view showing an embodiment of a gear polishing method using a gear polishing body according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the gear polishing body. FIG. 3 is an explanatory view of a polishing sheet constituting a gear polishing body, in which (a) is a front view, (b) is a side view, and (c) is a rear view. FIG. 4 is a diagram showing only a main part of the gear grinding body, and is a diagram showing a state in which the gear teeth are in sliding contact with the first thread surface of the thread-like grinding part. FIG. 5 is a diagram showing only the main part of the gear grinding body, and shows a state in which the gear teeth are in sliding contact with the second thread surface of the thread-like grinding part.

  Next, a specific embodiment of a gear polishing method using the gear abrasive according to the present invention will be described with reference to the drawings.

<Description of gear grinding device>
Gear grinding apparatus 1 shown in Figure 1, X perpendicular to each other, Y, Z-axis, and the total of four control axes system of θ axis Y-axis around the rotating shaft lines S ₁ around extending along the X-axis direction The rotationally driven main shaft 2 and the rotational axis S ₁ are at an obtuse angle at a position separated by a predetermined distance in the Y-axis direction orthogonal to the X-axis direction. helical abrasive object to be described later with respect to the axial direction and a table shaft 3 driven to rotate by the rotation axis S ₂ around extending in a direction forming a predetermined inclination angle in accordance with the tilt of the gear teeth.

A worm-shaped gear polishing body 4 is detachably mounted on the main shaft 2, and the gear polishing body 4 is rotated around the rotation axis S ₁ together with the main shaft 2 by rotational driving of the main shaft 2. .
A helical gear 5 (hereinafter simply referred to as “gear 5”) to be polished is detachably mounted on the table shaft 3, and the gear 5 rotates together with the table shaft 3 by the rotation of the table shaft 3. It is adapted to be rotated in the axis S ₂ around.

  In the gear polishing apparatus 1, a gear polishing body is obtained by synchronously driving the main shaft 2 and the table shaft 3, moving the main shaft 2 in the X, Y, and Z directions, and tilting the table shaft 3 in the θ-axis direction. The gear 5 can be polished while changing the meshing position between the gear 4 and the gear 5.

<Description of gear grinding body>
The gear polishing body 4 has a thread-like polishing portion 4a in which two thread portions are formed along two parallel virtual spiral curves (not shown). Threaded grinding portion 4a is formed in a geometry that can engage with the teeth 5a of the gear 5, rotating motion to the rotary axis lines S ₁ around the screw-shaped polishing portion 4a in a state of meshing with the teeth 5a of the gear 5 By doing so, the tooth surface of the gear 5 can be polished.

As shown in FIG. 2, the gear polishing body 4 includes a plurality of flexible polishing sheets 6 arranged in the axial direction of the rotation axis S <b> _{1 in} a state where the rotation centers coincide with each other, and these polishing sheets 6, which are stacked in the axial direction of the rotation axis S _1.

<Description of polishing sheet>
As shown in FIGS. 3A to 3C, the polishing sheet 6 includes a flexible sheet-like base material 8 in which an insertion hole 7 through which the main shaft 2 is inserted is formed. A necessary minimum polishing layer 9 is provided only on an edge of a later-described bulging portion 6a on the surface of one side of the material 8 (left side in FIG. 4B). Here, the polishing layer 9 is formed by attaching an abrasive to the base material 8 via an adhesive layer.

As shown in FIG. 3 (a), the polishing sheet 6 has a bulging portion 6a that swells outward in the radial direction from a virtual circle 10 whose diameter is the valley diameter of the thread-like polishing portion 4a.
The number of the bulging portions 6a provided in the polishing sheet 6 is the same as the number of threads of the thread-like polishing portion 4a. In this embodiment, the number of threads is 2, so that the bulging portions 6a. There two provided, these bulging portions 6a are arranged at equal intervals (every 180 °) in the circumferential direction about the center point O ₁ through the rotation axis S _1.

As shown in FIG. 2, in the gear-tooth polishing body 4, the bulging portion 6a an axial one another about the rotational axis lines S ₁ to position the shifting position by a predetermined angle rotation axis lines S ₁ of the polishing sheet 6 The thread-like polishing part 4a is formed by superimposing the two. Threaded grinding portion 4a which is formed in this manner, as shown in FIG. 4 illustrates an end portion of the thread profile section, in one direction (Figure rotational axis lines S ₁ about the said threaded grinding unit 4a 4, during the rotational movement in the direction of the arrow R, it is necessary for the teeth 5a of the gear 5 to distinguish the positional relationship between the adjacent abrasive sheets 6A and 6B (adjacent abrasive sheets 6 and 6) that are superposed on each other. In this case, the first thread surface 11 is slidably contacted while being moved relative to the lower step, and the other side portion of the thread-shaped portion is represented by the symbols “6A” and “6B”. As shown in FIG. 5, the tooth 5a of the gear 5 has a second thread surface 12 that is in sliding contact with each other while moving relative to each other so as to go up the steps of the adjacent polishing sheets 6A and 6B that are overlapped with each other. doing.

When the gear 5 is polished using the gear polishing body 4 configured as described above, the threaded polishing portion 4a is engaged with the teeth 5a of the gear 5 as shown in FIG. as Deneji shaped polishing portion 4a rotates motion to the rotational axis lines S ₁ about the way (Fig. 1 symbols R arrow direction), the rotation of the main shaft 2 rotates the gear for polishing body 4. As a result, as shown in FIG. 4, before the step 5 in the adjacent polishing sheets 6 </ b> A and 6 </ b> B overlapped with each other, the tooth 5 a of the gear 5 comes into contact with the polishing sheet 6 </ b> A on the front side over the step and after the step is exceeded. The tooth 5a of the gear 5 moves relative to the first thread surface 11 in the direction opposite to the direction in which the tooth 5a of the gear 5 bites between the polishing sheet 6B on the rear side beyond the step where the tooth 5a of the gear 5 contacts. Will be.
Simultaneously with the rotational operation of the gear abrasive 4, as shown in FIG. 1, rotational torque for pressing the teeth 5 a of the gear 5 against the first thread surface 11 (see FIG. 4) (in FIG. 1). Rotational torque in the direction indicated by the symbol T arrow) is applied from the table shaft 3 to the gear 5. Accordingly, as shown in FIG. 4, the pressing force pressing the polishing sheet 6 </ b> A on the front side over the step against the polishing sheet 6 </ b> B on the back side over the step is overlapped with the relative movement of the teeth 5 a with respect to the first thread surface 11. In addition, the tooth surfaces of the gear 5 are polished in a state where the polishing sheets 6A and 6B are sequentially added to the adjacent polishing sheets 6A and 6B and are more closely attached to each other.
Therefore, it is possible to reliably prevent the teeth 5a from biting between the adjacent polishing sheets 6A and 6B during the polishing operation of the gear 5.

  The gear grinding method using the gear grinding body of the present invention has been described based on one embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and does not depart from the spirit thereof. The configuration can be changed as appropriate within the range.

  The gear grinding method using the gear grinding body of the present invention has a characteristic that the gear teeth can be surely prevented from being caught between adjacent abrasive sheets during the gear grinding operation. Therefore, for example, it can be suitably used for the surface polishing of gear teeth used in transmissions and the like in the automobile field with emphasis on habitability and fuel consumption, and the industrial applicability is great.

DESCRIPTION OF SYMBOLS 1 Gear grinding apparatus 2 Main axis | shaft 3 Table axis | shaft 4 Gear grinding | polishing body 4a Thread-shaped grinding | polishing part 5 Gear 5a Tooth | gear 6 Polishing sheet 6a Swelling part 10 Virtual circle 11 1st thread surface 12 2nd thread surface

Claims (1)

A gear polishing body that has a thread-like polishing portion that is capable of rotating around a rotation axis and meshes with a tooth of a gear to be polished, and that polishes the tooth surface of the gear by the rotational movement of the screw-like polishing portion. A plurality of flexible abrasive sheets having bulges that bulge radially outward from a virtual circle whose diameter is the valley diameter of the thread-like abrasive part. A gear polishing method using a gear polishing body formed by forming the thread-like polishing portion by overlapping the polishing sheets in the rotation axis direction while being shifted from each other around,
The thread-like polishing portion is relatively positioned so that the teeth of the gears go down the steps of the adjacent abrasive sheets that are overlapped with each other when the screw-like polishing portion rotates in one direction around the rotation axis. A first screw thread surface that is in sliding contact while moving, and a second screw thread surface that is in sliding contact while relatively moving so that the teeth of the gears rise over the steps of the adjacent abrasive sheets that are superimposed on each other. Then, while rotating the thread-like polishing portion in one direction around the rotation axis, a rotational torque for pressing the gear teeth against the first thread surface is applied to the gear to polish the gear teeth. A gear polishing method using a gear polishing body.

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