JP2010030003A - Regulating wheel drum for centerless grinding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regulating wheel drum for centerless grinding capable of securing a spark-out grinding region, improving roundness and surface roughness of a conical work, and reducing man-hours. <P>SOLUTION: In the regulating wheel drum 10 for through feed centerless grinding, an angle δd formed by bottom faces 10aa of respective peripheries of a screw groove 10a continuing spirally and a drum axis Dj is made constant over entire area of the drum, and an envelope line L2 connecting same locations in the axial direction of respective peripheries of the screw groove 10a along the axial direction of the drum is made a curved line protruding outward in the radial direction over the axial direction of the drum. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a screw-type adjusting wheel drum used for through-feed centerless grinding of an outer diameter of a conical workpiece, such as a tapered roller of a tapered roller bearing, for example, the roundness and surface roughness of the outer diameter of the conical workpiece. It is related with the adjustment wheel drum for centerless grinding which improves processing accuracy, such as.

Conventionally, through-feed centerless grinding in which the outer diameter of a conical workpiece is ground straight has been practically used (Patent Documents 1 to 3). As shown in FIG. 10, in the adjustment wheel drum 1 used in this through-feed centerless grinding, the envelope L1 that connects the same positions in the axial direction of each circumference of the inclined groove 2 is usually straight. Further, in order to obtain a so-called spark-out grinding region that is near the final region where the workpiece Wa is finished, as shown in FIG. 11, the shape of the grinding wheel 3 is, for example, an R shape that is convex outward in the radial direction. There is a case.
In addition, the machine and the grindstone are elastically deformed in the grinding state of the workpiece Wa, and the fine grinding state due to the recovery of the elastic deformation by stopping the cutting of the grindstone is usually called spark-out grinding. A region near the final region where the workpiece Wa is finished, which is a grinding region, is referred to as a spark-out grinding region, thereby improving the roundness and surface roughness of the workpiece Wa.
Japanese Patent No. 3772955 Japanese Patent No. 3871015 Japanese Patent No. 3888469

The envelope of the adjusting wheel drum used for conventional through-feed centerless grinding is straight as shown in FIG. 10, and a spark-out grinding area cannot be secured. In this case, the workpiece dimensional change is a straight line with respect to the grinding wheel width from the grinding wheel inlet to the outlet, as shown in FIG. In this state, there is no spark-out grinding area in the grinding process. Therefore, the roundness and surface roughness of the work cannot be improved.
In order to obtain a spark-out grinding region, as shown in FIG. 11, when the grindstone shape of the outer peripheral surface 3a of the grinding grindstone 3 is, for example, an R shape that protrudes radially outward, the following problem is caused. There is. Since there is a difference in the workpiece allowance Wt for each workpiece model number, it is necessary to change the grindstone shape for each workpiece model number by changing the dresser template or the like. Therefore, an increase in the amount of wear of the grindstone due to dressing for changing the shape of the grindstone, and an increase in man-hours (dressing work, template replacement, etc.) therefor occur.

  An object of the present invention is to provide an adjustment drum for centerless grinding that can secure a spark-out grinding region, can improve the roundness and surface roughness of a conical workpiece, and can reduce the number of steps. That is.

The adjustment drum for centerless grinding according to the present invention is an adjustment wheel drum for through-feed centerless grinding, and has a spiral thread groove on the outer periphery, and the bottom surface of each circumference of the screw groove forms a conical portion. And a rotatable adjustment wheel drum having a flange portion between the cone-shaped portions and being rotationally driven around the drum shaft core to roll-contact the cone-shaped workpiece to the bottom surface of the screw groove. The angle formed between the bottom surface and the drum shaft core is the same angle throughout the drum, and the axial direction of each circumference of the screw groove in the cross section of the adjusting wheel drum cut along an arbitrary virtual plane including the drum shaft core An envelope connecting the same portions along the drum axis direction is a convex curve protruding radially outward over the drum axis direction.

According to this configuration, the cone-shaped workpiece is supported by the adjusting wheel drum and the plate-like member so as to be in rolling contact with the bottom surface of the screw groove of the adjusting wheel drum, and the cone-shaped workpiece is rotated by the grinding wheel that is rotationally driven. The outer peripheral surface is ground.
In particular, the angle formed between the bottom surface of each circumference of the thread groove and the drum axis is the same angle throughout the drum, and the same axial position of each circumference of the thread groove is along the drum axis direction. By making the connecting envelope curve a convex curve that protrudes radially outward over the drum axis direction, a spark-out grinding region in which the cutting per grinding is close to zero can be secured. Therefore, processing accuracy such as roundness and surface roughness of the conical workpiece can be improved. In this case, there is no need to change the shape of the grinding wheel for each model number of the conical workpiece, so the amount of grinding wheel wear due to dressing for changing the grinding wheel shape does not increase, and the man-hours for that purpose can also be reduced. . Therefore, the production efficiency of the conical workpiece can be increased, and the manufacturing cost can be reduced.

The envelope may be an arc. Thus, a desired spark-out grinding region can be obtained by making the arc shape of the envelope.
Conveying the cone-shaped workpiece on the grinding wheel at the position of the screw groove furthest away from the drum axis in the radial direction with respect to the grinding wheel grinding the outer peripheral surface of the cone-shaped workpiece to be brought into rolling contact with the thread groove It may be near the downstream end in the direction or near the downstream end in the transport direction. When the position of the thread groove farthest radially outward from the drum axis relative to the grinding wheel, that is, the vertex position of the so-called envelope is the downstream end in the conveying direction of the conical workpiece, the conical workpiece is upstream in the conveying direction. As the workpiece is conveyed from the side to the downstream side, the workpiece machining allowance can be gradually reduced. Therefore, spark-out grinding can be performed on the downstream side in the conveyance direction of the conical workpiece. By setting the vertex position of the envelope near the downstream end in the transport direction, that is, slightly inside the work exit side end of the grinding wheel, spark-out grinding can be performed on the downstream side in the transport direction of the conical workpiece, and the spark out It is possible to smoothly escape the conical workpiece after grinding, and to prevent the occurrence of scratches due to the grindstone edge.

  The outer peripheral surface of the cone-shaped workpiece may have an envelope shape corresponding to the machining allowance to be ground. By making such an envelope-shaped adjusting wheel drum, the outer peripheral surface of the grinding wheel can be made flat and is not changed for each model number of the conical workpiece. In other words, the versatility of the grinding wheel can be improved, and the number of man-hours associated with changing the model number of the conical workpiece can be reduced.

  A jig body having a reference surface that contacts the conical portion of the screw groove and an end surface that contacts one side surface of the flange, and a measurement gauge that is provided on the jig body and measures a distance in the vertical direction with respect to the reference surface The angle formed by the bottom surface of the thread groove and the drum axis may be obtained using a measuring jig provided with The reference surface of this measuring jig was applied to a predetermined cone-shaped portion of the adjustment wheel drum, the measuring gauge probe was applied to the other cone-shaped portion, and the cone-shaped portion applied to the reference surface and the measurement gauge were applied. Measure the parallel step with the conical part. The inclination angle of the bottom surface of the thread groove is obtained from the measured value of the parallel step and the lead of the thread groove. By using such a measuring jig, the parallel step can be measured accurately and easily only by pressing the reference surface against the conical portion, and therefore the inclination angle of the bottom surface of the thread groove can be determined. It can be obtained accurately and easily.

The reference surface of the jig body is pressed against the bottom surface of the screw groove that is furthest radially outward from the drum shaft core, and the end surface of the jig body is pressed against one side surface of the flange that follows the bottom surface. The first drum angle step, which is a parallel step from one cone-shaped portion to another cone-shaped portion, is obtained from the measured value measured by the measurement gauge, and the jig body is positioned at which the measured value is obtained. The reference surface of the jig body is pressed against the bottom surface of the screw groove that is shifted by one lead, and the end surface of the jig body is pressed against one side surface of the flange that follows the bottom surface. A second step which is a parallel step from one conical shape portion to another conical shape portion based on a measurement value measured by bringing a probe of a measurement gauge into contact with the bottom surface of the thread groove farthest outward in the direction. The drum angle step is obtained and obtained from these first and second drum angle steps. That angle may be the angle of the bottom surface of the thread groove with respect to the drum axis.
The “parallel step” includes a substantially parallel step from one conical shape portion to another conical shape portion.

  Since the envelope is a convex curve projecting radially outward in the drum axis direction, the drum angular step changes depending on the measurement position. However, the drum angle step may be measured in the vicinity of the workpiece exit, which is the final finished portion related to the apex angle of the conical workpiece. Also, when the crowning curvature of the envelope is very large, the influence of the crowning on the drum angle step is small in the vicinity of the crowning vertex of the envelope. The reference surface of the jig body is pressed, and the end surface of the jig body is pressed against one side surface of the flange that follows the bottom surface to obtain the first drum angle step. In addition, the reference surface of the jig main body is pressed against the bottom surface of the thread groove shifted by one lead, and the end surface of the jig main body is pressed against one side surface of the flange that follows the bottom surface, A measuring element is brought into contact with the bottom surface of the separated screw groove to obtain a second drum angle step. From these drum angle steps, the desired angle of the bottom surface of the thread groove can be obtained.

  The reference surface of the jig body is pressed against the bottom surface that is shifted by 1/2 lead from the bottom surface of the thread groove that is farthest radially outward from the drum shaft core, and on one side surface of the flange that follows the bottom surface. The drum angle step, which is a parallel step from one cone-shaped portion to another cone-shaped portion, is obtained from the measured value measured by the measurement gauge by pressing the end face of the jig body, and obtained from this drum angle step. The angle formed may be the angle of the bottom surface of the thread groove with respect to the drum axis. In this case, the drum angle step can be determined more accurately without being influenced by the protruding amount of the convex curve of the adjusting wheel drum, the so-called crowning amount.

  The intersection of the bottom surface of the screw groove that is furthest radially outward from the drum shaft core and one side surface of the flange that follows this bottom surface is the reference position of the drum shaft direction position, and on the bottom surface of any screw groove, While pressing the reference surface of the jig main body, the end surface of the jig main body is pressed against one side surface of the flange that follows the bottom surface, and the drum angle step is obtained from the measurement value measured by the measurement gauge. The curvature obtained from the step and the axial distance from the reference position may be the crowning curvature of the envelope. By using the adjusting wheel drum having such a crowning curvature, it is possible to grind a conical workpiece and easily improve processing accuracy such as roundness and surface roughness of the conical workpiece.

An adjustment wheel drum for centerless grinding according to the present invention is an adjustment wheel drum for through-feed centerless grinding, and has a spiral thread groove on the outer periphery, and the bottom surface of each circumference of the screw groove forms a conical portion. And a rotatable adjusting wheel drum that has a flange between the conical portions and is rotationally driven around the drum axis to cause the conical workpiece to roll into contact with the bottom surface of the thread groove.
The angle formed between the bottom surface of each circumference of the screw groove and the drum shaft core is the same angle throughout the drum, and the screw wheel is cut in an arbitrary virtual plane including the drum shaft core. Since the envelope that connects the same axial direction of each circumference of the groove along the drum axis direction is a convex curve that protrudes radially outward over the drum axis direction, a spark-out grinding region can be secured, and the cone The roundness and surface roughness of the shaped workpiece can be improved, and the number of man-hours can be reduced.

  An embodiment of the present invention will be described with reference to FIGS. The adjusting wheel drum according to this embodiment is used, for example, when through-feed centerless grinding of the outer peripheral surface of a tapered roller of a tapered roller bearing. The following description also includes a description of a measurement method for measuring the inclination angle of the conical portion of the adjustment wheel drum. As shown in FIGS. 1 and 2, the through-feed centerless grinding apparatus for through-feed centerless grinding of the outer peripheral surface of the conical workpiece mainly includes the adjusting wheel drum 10, the blade 11 (FIG. 2), and the grinding wheel 12. And. Among these, the shaft core of the adjusting wheel drum 10, that is, the drum shaft core Dj, and the shaft core Kj of the grinding wheel 12 are arranged so as to be substantially parallel.

A schematic configuration of the adjusting wheel drum 10 will be described.
The adjusting wheel drum 10 is attached to the outer periphery of the drum shaft 13. This adjusting wheel drum 10 has a spiral thread groove 10a on the outer periphery, and the bottom surface 10aa of each circumference of the screw groove 10a forms a conical shape, and is driven to rotate around the drum axis Dj of the drum shaft 13. Is done. The adjusting wheel drum 10 has a rotatable configuration in which a workpiece W made of a conical workpiece is brought into rolling contact with the bottom surface 10aa of the screw groove 10a. The bottom surface 10aa of the thread groove 10a is defined by a spiral flange 10b, and is formed in a conical shape following the spiral.

As shown in FIG. 2, the blade 11 is a plate-like member formed in a plate shape. At least the upper end edge 11a of the plate-like member is interposed between the adjusting wheel drum 10 and the grinding wheel 12, and the workpiece W is supported along the upper end edge 11a. Further, the blade 11 supports the outer peripheral surface of the workpiece W so that the workpiece is in rolling contact with the bottom surface 10aa of the screw groove 10a. A top plate (not shown) for preventing the workpiece W from jumping up is provided above the blade 11 and on the workpiece W.
The grinding wheel 12 is formed in a cylindrical shape, is driven to rotate around an axis substantially parallel to the adjustment wheel drum 10, and grinds the outer peripheral surface of the work W supported by the adjustment wheel drum 10 and the blade 11. That is, the outer diameter of the workpiece W is ground by passing the workpiece W between the adjusting wheel drum 10 having the thread groove 10 a and the flange portion 10 b and the outer peripheral surface of the grinding wheel 12. As shown in FIG. 1, the outer peripheral surface of the grinding wheel 12 is flat in a plan view and is not changed for each model number of the workpiece W.

The detailed configuration of the adjustment wheel drum 10 will be described.
As shown in FIG. 3, the angle δd formed by the bottom surface 10aa of each circumference of the thread groove 10a and the drum axis Dj is the same angle throughout the drum. This angle δd is referred to as “drum angle δd”.
In the cross section of the adjusting wheel drum 10 cut along an arbitrary virtual plane including the drum axis Dj, an envelope L2 that connects the same axial direction of each circumference of the screw groove 10a along the drum axis direction is a drum axis. The adjusting wheel drum 10 is formed so as to have a convex curve protruding outward in the radial direction over the core direction. As shown in FIGS. 1 and 3, the envelope L2 is an arc, and the crowning curvature Rsc is determined by the workpiece entrance side opening amount of the envelope L2 of the thread groove 10a within the grinding wheel width H1 of the grinding wheel 12. The curvature is set to be about the chamfering allowance Wt. Also, as shown in FIG. 1, an envelope L3 that connects the outer diameters of the plurality of flanges 10b arranged in the drum axis direction is an envelope that connects the same axial position of each circumference of the thread groove 10a along the drum axis direction. It is formed in the same shape as the line L2.

  As shown in FIG. 1, the position P1 of the thread groove 10a farthest radially outward from the drum axis Dj with respect to the grinding wheel 12 is defined as the conical workpiece, that is, the workpiece W conveyance direction in the grinding wheel 12. The downstream end or the vicinity of the downstream end in the transport direction is used. In these cases, the dimensional change of the outer peripheral surface of the workpiece W can be a smooth curve as shown in FIGS. As shown in FIG. 1, since the envelope L2 is a convex curve projecting radially outward, the position P1 of the screw groove 10a farthest radially outward is defined as described above. A grinding area SA can be provided. The position P1 of the screw groove 10a farthest radially outward is synonymous with the so-called vertex position of the envelope L2. The apex position of the envelope L2 is slightly closer to the downstream end in the conveyance direction of the workpiece W in the grinding wheel 12 shown in FIG. It is more desirable to be on the upstream side (inside). The reason for this is that the workpiece W after the spark-out grinding can be smoothly relieved and scratches caused by the grinding wheel edge of the grinding wheel 12 can be prevented.

A method for measuring the drum angle δd of the adjusting wheel drum 10 will be described.
As shown in FIG. 3, the drum angle δd can be measured using a measuring jig 14. The measurement jig 14 includes a jig body 15 having a bottom surface serving as a reference surface 15a, and a measurement gauge 16 that measures a distance in the vertical direction with respect to the reference surface 15a. An end surface 15b following the reference surface 15a of the jig body 15 is formed so as to be able to abut on one side surface 10ba of the flange portion 10b. The end surface 15b is formed perpendicular to the reference surface 15a.
The measurement gauge 16 has a needle-like probe 16a and a meter 16b. Among these, the measuring element 16a is held by the jig body 15 in a state in which the measuring element 16a can move in the direction perpendicular to the reference surface 15a. The meter 16b indicates the moving distance of the probe 16a.

As shown in FIG. 3, the reference surface 15a is applied to the bottom surface 10aa-1 of the screw groove 10a, and the probe 16a is applied to the bottom surface 10aa-2 of the screw groove 10a adjacent in the axial direction. The distance with respect to the reference surface 15a required to apply the measuring element 16a to the bottom surface 10aa-2 at this time is read from the meter 16b, and this is defined as a parallel step Hd between the bottom surfaces 10aa-1 and 10aa-2 of the screw groove 10a. Since the lead Ld of the screw groove 10a is predetermined as a design value, the drum angle δd is obtained by the following equation (1).
δd = sin ⁻¹ (Hd / Ld) (1)

  The measurement of the parallel step Hd is performed only by placing the reference surface 15a against the bottom surface 10aa-1 of the screw groove 10a and then bringing the measuring element 16a against the bottom surface 10aa-2 of the adjacent screw groove 10a. The operation is extremely easy if the reference surface 15a can be applied to the bottom surface 10aa of the thread groove 10a. Further, if the reference surface 15a can be applied to the bottom surface 10aa of the thread groove 10a, the parallel step Hd can be accurately measured without being affected by the length. In measuring the parallel step Hd, the jig body 15 or the measurement gauge 16 is measured while being swung in the circumferential direction of the adjustment wheel drum 10, and the maximum value of the measured value is defined as the parallel step Hd. Since this maximum value corresponds to the measured value at the tangential position of the bottom surface 10aa of the thread groove 10a, the obtained parallel step value Hd is highly accurate.

Here, since the aforementioned envelope L2 is a convex curve protruding outward in the radial direction, the parallel step Hd (drum angle step Hd) of the drum angle δd varies depending on the measurement position. However, the drum angle step Hd may be measured in the vicinity of the workpiece exit, which is the final finished portion related to the apex angle of the conical workpiece.
Specifically, as shown in FIG. 3, the bottom surface 10aa-1 is shifted to the downstream side in the conveyance direction by 1/2 lead from the bottom surface 10aa of the screw groove 10a farthest radially outward from the drum axis Dj. Then, the reference surface 15a of the jig body 15 is pressed. At the same time, the end surface 15b of the jig body 15 is pressed against one side surface 10ba of the flange portion 10b following the bottom surface 10aa-1. Further, the contact angle 16a of the measurement gauge 16 is applied to the bottom surface 10aa-2 of the screw groove 10a which is shifted to the upstream side in the transport direction, which is shifted by 1/2 lead, so that the drum angle is not affected by the crowning amount of the envelope L2. The step Hd, that is, the drum angle δd can be measured.

  In addition, when the crowning curvature Rsc of the envelope L2 is very large (the case where the crowning curvature Rsc is very large is, for example, crowning R200,000 mm. Depending on the machining allowance and the grindstone width, it is larger than R200,000 mm. In the case, the difference in Hdx is small (for example, within 0.003) near the top of the crowning curvature (within ± 1 lead), that is, acceptable because the difference in drum angle is small. Then, the influence on the drum angle step Hd by the crowning is small. For this reason, as shown in FIG. 6, the jig body 15 is pressed against the bottom surface 10aa-1 of the thread groove 10a farthest radially outward from the drum axis Dj, and the flange portion following the bottom surface 10aa-1 10b, the end face 15b of the jig body 15 is pressed against one side face 10ba, and the drum angle step Hd is measured, and as shown in FIG. 7, one lead from the position of the bottom face 10aa-1 of the thread groove 10a. The jig body 15 is pressed against the bottom surface 10aa-2 of the separated screw groove 10a, and the end surface 15b of the jig body 15 is pressed against one side surface 10ba of the flange portion 10b following the bottom surface 10aa-2. The measuring element 16a of the measurement gauge 16 is applied to the bottom surface 10aa-1 of the thread groove 10a farthest radially outward from the drum axis Dj, and the measurement state is between the state in which the drum angular step Hd is measured. It may be.

As shown in FIG. 8, by measuring a drum angle step Hdx away from the apex Pa of the envelope L2 in the bottom surface 10aa of the thread groove 10a, the same axial position of each circumference of the thread groove 10a is measured. The crowning curvature Rsc of the envelope L2 connecting the two can be obtained.
This will be described with reference to FIG.
The intersection of the bottom surface 10aa of the thread groove 10a farthest radially outward from the drum shaft core and one side surface 10ba of the flange portion 10b following this bottom surface 10aa (this is referred to as the “surface surface 10ba”), in other words, The vertex Pa of the envelope L2 at the intersection P between the flange surface 10ba and the inclined groove is used as a reference in the axial direction. When the axial distance from the vertex Pa to an arbitrary point Px1 on the envelope L2 is Lsx1, and the axial distance from the next arbitrary point Px2 on the envelope L2 is Lsx2, the following expression is obtained.

Hd = Ld · sinδd (2)
Δdw1 = Rsc−√ (Rsc ² −Lsx1 ² ) (3)
Δdw2 = Rsc−√ (Rsc ² −Lsx2 ² ) (4)
Hdx = Hd− (Δdw2−Δdw1) · cosδd (5)
Here, the lead of the thread groove 10a is Ld, the radial distance from the vertex Pa to the point Px1 is Δdw1, and the radial distance from the vertex Pa to the point Px2 is Δdw2.
Substituting Equations (3) and (4) into Equation (5),
[√ (Rsc ² −Lsx1 ² ) −√ (Rsc ² −Lsx2 ² )] = (Hd−Hdx) / cosδd
Square both sides,
2 · Rsc ² −Lsx1 ² −Lsx2 ² − (Hd−Hdx) ² / cos ² δd = 2 · √ {(Rsc ² −Lsx1 ² ) · (Rsc ² −Lsx2 ² )}
Squared on both sides and calculating crowning curvature: Rsc
Rsc = √ <[{Lsx1 ² + Lsx2 ² + (Hd−Hdx) ² / cos ² δd} ² −4 · Lsx1 ² · Lsx2 ² ] / [4 · (Hd−Hdx) ² / cos ² δd]> ... (6)
From Equation (6), the crowning curvature: Rsc can be obtained from the measured drum angle step Hdx. Using the adjusting wheel drum 10 having such a crowning curvature Rsc, the outer peripheral surface of the workpiece W can be ground, and the processing accuracy such as roundness and surface roughness of the workpiece W can be easily improved.

  According to the configuration described above, the workpiece W is supported by the grinding wheel 12 that is rotationally driven while being supported by the adjustment wheel drum 10 and the blade 11 so as to be in rolling contact with the bottom surface 10aa of the screw groove 10a of the adjustment wheel drum 10. The outer peripheral surface of the workpiece W is ground. In particular, the angle δd formed between the bottom surface 10aa of each circumference of the screw groove 10a and the drum shaft core Dj is set to the same angle throughout the entire drum, and the same axial position of each circumference of the screw groove 10a is set to the drum shaft core. By making the envelope L2 connected along the direction into a convex curve projecting radially outward over the drum axis direction, it is possible to secure a spark-out grinding area SA where the depth of cut per grinding is close to zero. Therefore, processing accuracy such as roundness and surface roughness of the conical workpiece can be improved. In this case, since it is not necessary to change the shape of the grinding wheel 12 for each model number of the conical workpiece, the amount of wear of the grinding wheel due to dressing for changing the shape of the grinding wheel does not increase, and the man-hour for that purpose can also be reduced. it can. Therefore, the production efficiency of the conical workpiece can be increased, and the manufacturing cost can be reduced.

A desired spark-out grinding area SA can be obtained by making the envelope L2 into an arc shape. When the apex position of the envelope L2 is set to the downstream end in the conveying direction of the conical workpiece with respect to the grinding wheel 12, that is, the workpiece outlet side end of the grinding wheel 12, the workpiece W is transferred from the upstream side to the downstream side in the conveying direction. Therefore, the workpiece allowance can be gradually reduced. Therefore, as shown in FIG. 4, spark-out grinding can be performed on the downstream side in the conveyance direction of the workpiece W.
When the apex position of the envelope L2 is set in the vicinity of the downstream end in the transport direction, that is, slightly inside the work exit side end of the grinding wheel 12, spark-out grinding is performed on the downstream side in the transport direction of the work W as shown in FIG. In addition, the workpiece W after the spark-out grinding can be smoothly relieved and scratches caused by the grindstone edge can be prevented.

The adjustment wheel drum 10 may have an envelope shape corresponding to the machining allowance for grinding the outer peripheral surface of the workpiece W. By using the adjustment wheel drum 10 having such an envelope shape, the outer peripheral surface of the grinding wheel 12 can be made flat, and there is no need to change it for each model number of the workpiece W. In other words, the versatility of the grinding wheel 12 can be improved, and the number of man-hours associated with changing the model number of the workpiece W can be reduced.
As another embodiment of the present invention, the adjusting wheel drum may be used when superfinishing. As an example of an embodiment of the present invention, a cone-shaped workpiece has been described, but the outer peripheral surface may be a cylindrical workpiece. In this case, the angle of the bottom surface of each circumference of the thread groove with respect to the drum axis is zero.

1 is a plan view of a through-feed centerless grinding apparatus according to an embodiment of the present invention. It is a front view of the through-feed centerless grinding apparatus. It is a figure which illustrates roughly the measuring method of the drum angle of the adjustment wheel drum of the centerless grinding apparatus. It is a figure showing the relationship between a grinding wheel width | variety and the dimensional change amount in the grinding wheel width of a cone-shaped workpiece. It is a figure showing the relationship between the grinding wheel width | variety at the time of making the vertex position of an envelope line inward slightly from the workpiece | work exit side end of a grinding wheel, and the dimensional change amount in the grinding wheel width of a cone-shaped workpiece. It is a figure showing the state which presses a jig | tool main body to the bottom face of the thread groove furthest to the radial direction outward from the drum axis | shaft, and measures a drum angle | corner level | step difference. The jig body is pressed against the bottom surface of the thread groove that is shifted by one lead from the position of the bottom surface of the thread groove, and the gauge gauge probe is applied to the bottom surface of the thread groove that is farthest radially outward. It is a figure showing the state which measures a level | step difference. It is a figure showing the state which calculates | requires the crowning curvature of an envelope. It is a figure showing the relationship between a crowning curvature and each point etc. on an envelope. It is a top view of the through feed centerless grinding apparatus of a prior art example. It is a top view of the through-feed centerless grinding apparatus of another conventional example. It is a figure which concerns on a prior art and represents the relationship between the grinding wheel width and the inner and outer diameter dimensions of the wheel width of the conical workpiece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Adjusting wheel drum 10a ... Screw groove 10aa ... Bottom surface 10b ... Ridge part 12 ... Grinding wheel 14 ... Measuring jig 15 ... Jig body 15a ... Jig reference surface 15b ... Jig end face 16 ... Measurement gauge Dj ... Drum axis L2 ... Envelope W ... Workpiece

Claims (8)

This is an adjustment wheel drum for through-feed centerless grinding, which has a spiral thread groove on the outer periphery, the bottom surface of each circumference of this thread groove forms a conical part, and a flange part between the conical part. In a rotatable adjustment wheel drum that is driven to rotate around the drum axis and causes the cone-shaped workpiece to roll into contact with the bottom surface of the thread groove,
The angle formed between the bottom surface of each circumference of the thread groove and the drum axis is the same angle throughout the drum,
In a cross-section obtained by cutting the adjustment wheel drum along an arbitrary virtual plane including the drum axis, an envelope connecting the same axial position of each circumference of the thread groove along the drum axis direction has a diameter extending in the drum axis direction. An adjustment wheel drum for centerless grinding that is a convex curve protruding outward in the direction.   The centerless grinding adjusting wheel drum according to claim 1, wherein the envelope is an arc.   The position of the screw groove that is farthest radially outward from the drum shaft core is the same as that of the grinding wheel for grinding the outer peripheral surface of the conical workpiece that is in rolling contact with the screw groove. An adjustment wheel drum for centerless grinding in a grinding wheel in the vicinity of the downstream end in the conveying direction of the conical workpiece or in the vicinity of the downstream end in the conveying direction.   4. The centerless grinding adjusting wheel drum according to claim 1, wherein the outer peripheral surface of the conical workpiece has an envelope shape corresponding to a machining allowance to be ground. 5. In any one of Claims 1 thru | or 4,
A jig body having a reference surface that contacts the conical portion of the screw groove and an end surface that contacts one side surface of the flange;
For centerless grinding where the angle between the bottom surface of the thread groove and the drum shaft core is required using a measuring jig provided on the jig body and measuring a distance in a direction perpendicular to the reference surface Adjusting car drum. 6. The jig main body according to claim 5, wherein a reference surface of the jig main body is pressed against a bottom surface of the screw groove that is furthest radially outward from the drum shaft core, and the jig main body is attached to one side surface of the flange that follows the bottom surface. The first drum angle step, which is a parallel step from one cone-shaped portion to another cone-shaped portion, is obtained from the measured value measured by the measurement gauge.
The jig body is pressed against the bottom surface of the screw groove shifted by one lead from the position where the measurement value is obtained, and the jig body is pressed against the side surface of the flange that follows the bottom surface. Press the end face of the tool body, and measure from the measured value measured by bringing the gauge gauge probe into contact with the bottom surface of the thread groove farthest radially outward from the drum axis. Obtaining a second drum angle step which is a parallel step to the cone-shaped portion of
An adjustment drum for centerless grinding in which an angle obtained from the first and second drum angle steps is an angle of the bottom surface of the thread groove with respect to the drum axis.   6. The jig according to claim 5, wherein the reference surface of the jig main body is pressed against the bottom surface that is shifted by ½ lead from the bottom surface of the thread groove that is farthest radially outward from the drum axis, and The end face of the jig body is pressed against one side of the part, and a drum angle step which is a parallel step from one conical part to another conical part is obtained from the measurement value measured by the measurement gauge, An adjustment drum for centerless grinding in which an angle obtained from the drum angle step is an angle of the bottom surface of the thread groove with respect to the drum axis. 8. The intersection of the bottom surface of the thread groove furthest away radially outward from the drum shaft core and one side surface of the flange that follows the bottom surface in the drum shaft core direction according to claim 5. The reference position of the position,
While pressing the reference surface of the jig body against the bottom surface of any thread groove, pressing the end surface of the jig body against one side surface of the flange that follows the bottom surface, from the measurement value measured by the measurement gauge, Find the drum angle step, which is a parallel step from one cone-shaped part to another cone-shaped part,
An adjustment wheel drum for centerless grinding in which the curvature obtained from the drum angle step and the axial distance from the reference position is the crowning curvature of the envelope.

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