JP2010274403A - Method and device for step-centerless-grinding spiral workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique of centerless grinding for performing step processing on an outside of a workpiece with high accuracy by an infeed-grinding method by utilizing the characteristics of a spiral workpiece. <P>SOLUTION: The outer diameter part of a non-ground portion of the spiral workpiece W is supported and rotated by a regulating wheel 2, a blade 3 and a press rotating device 4, and a thrust force is applied to the workpiece W in the direction of the axial positioning stopper 5 by the regulating wheel 2 and the press rotating device 4. While the workpiece is compressed in the axial direction and made to be a rigid body thereby, the step processing is applied to the outer diameter part of the workpiece W by relatively cut-feeding a grinding wheel 1 into the outer diameter part of the workpiece W. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stepless centerless grinding method and apparatus for a spiral workpiece, and more specifically, an infeed grinding method for an outer diameter portion of a spiral workpiece in which strands are spirally formed. The present invention relates to a centerless grinding technique suitable for stepping by means of.

  In general, an infeed grinding type centerless grinding technique is suitably used to perform stepping on the outer diameter portion of a cylindrical workpiece (hereinafter referred to as a workpiece).

  In this grinding method, the workpiece to be ground is rotated and supported by an adjustment wheel and a blade, and grinding is performed while relatively cutting and feeding a grinding wheel that is driven to rotate with respect to the outer diameter surface of the workpiece. A stepping process is performed on the outer diameter surface of the workpiece (see, for example, Patent Document 1).

  By the way, for example, a spiral workpiece W as shown in FIG. 6 (the illustrated workpiece is a so-called Z-winding (right-handed) spiral workpiece) is an elastic body structure in which the wire w is spirally formed. In other words, the spiral workpiece W itself can be regarded as an assembly of continuous strands w, which has elasticity in the axial center X direction and twists in the outer circumference Y direction. It has the characteristic that it is easy to occur and the entire spiral workpiece W is very easily bent.

  As far as the present applicant knows, there is no patent document or the like that discloses a conventional technique in which this type of spiral workpiece W is stepped by centerless grinding.

JP 7-246548 A

  For the spiral workpiece W having such characteristics, for example, when the stepped machining as shown in FIG. 6B is performed by centerless grinding using the conventional general in-feed grinding method described above, the spiral workpiece W itself is a rigid body. Therefore, the spiral workpiece W shape cannot be stably maintained, and it has been experimentally found that the following various problems occur. Grinding makes it difficult or impossible to step the spiral workpiece W, and there has been a demand for improvement.

(1) In the so-called Z-wound spiral workpiece W (see FIG. 7A), the conventional general in-feed centerless grinding can be performed with ordinary general precision grinding. Grinding that requires high precision is impossible.

  Specifically, in the case of conventional general in-feed centerless grinding, a grinding wheel that rotates at high speed with respect to the outer diameter portion of the end portion of the spiral workpiece W while being rotatably supported by the adjusting wheel b and the blade c. In other words, the spiral workpiece W is rotated at a high speed by the grinding wheel a, while the high-speed rotation is braked by the adjusting wheel b so that the spiral workpiece W is rotated at a predetermined rotational speed. Will be rotated. d indicates a positioning stopper for positioning the axial position of the spiral workpiece W.

  Therefore, in the spiral work W having an elastic body structure in which the wire w is wound and formed, in addition to not being able to stably hold the shape, the braking effect by the adjustment vehicle b can be obtained stably. Therefore, high-precision grinding cannot be expected.

(2) In the so-called S-wound spiral workpiece W (see FIG. 7B), the rotation of the adjustment wheel b in the normal rotation direction (hereinafter referred to as normal rotation) Since a force is applied in the direction in which the wire w can be unwound, the wire w of the spiral workpiece W is unwound and cannot be processed. On the contrary, if the rotation direction of the adjusting wheel b is rotated in the direction opposite to the normal rotation, the spiral workpiece W does not rotate and the machining cannot be performed.

(3) The shorter the length of the grinding portion of the spiral workpiece W, the more difficult the spiral workpiece W rotates, and the excessively short spiral workpiece W does not rotate. I can't.

(4) Since the spiral workpiece W is rotated at the grinding portion of the spiral workpiece W, when the spiral workpiece W is thinned, it is easily twisted and broken by the rotational force (see within a one-dot chain line circle in FIG. 7C).

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to use the characteristics of the spiral workpiece so that the outer diameter portion of the spiral workpiece is obtained by the in-feed grinding method. It is an object of the present invention to provide a centerless grinding method capable of performing stepping processing with high accuracy.

  Another object of the present invention is to provide a centerless grinding apparatus capable of suitably carrying out the centerless grinding method.

  In order to achieve the above object, a centerless grinding method of the present invention is a centerless grinding method in which stepping is performed on an outer diameter portion of a spiral workpiece in which strands are spirally formed. The outer diameter portion of the non-grinding portion is supported and rotated by a press rotating means provided in parallel with the adjusting wheel, the blade, and the grinding wheel, and the helical work is moved in the axial positioning stopper direction by the adjusting wheel and the press rotating means. By applying thrust and thereby compressing the spiral workpiece in the axial direction to make it rigid, the grinding wheel is relatively cut and fed to the outer diameter portion of the workpiece, thereby providing a step to the outer diameter portion of the spiral workpiece. It is characterized in that it is subjected to an attaching process.

The following configuration is adopted as a preferred embodiment.
(1) The presser rotating means includes a presser roller that rolls in contact with the outer diameter portion of the non-ground portion of the spiral workpiece with a predetermined pressing force.

(2) By tilting at least one of the rotation shafts of the adjusting wheel and the pressing roller of the presser rotating means with respect to the rotational axis of the spiral workpiece, a skew force is applied to the spiral workpiece, and the spiral shape Apply the above thrust to the workpiece.

  Here, “skew” means a state in which the spiral workpiece is twisted in the outer diameter circumferential direction, and “skew force” means that the spiral workpiece is twisted in the outer diameter circumferential direction. 6 (in other words, in FIG. 6A, a force acting so that the straight line L on the outer diameter parallel to the axis X moves and inclines in the outer circumferential direction (see the two-dot chain line)). (The same shall apply hereinafter in the present specification and claims).

(3) The rotation direction of the adjusting wheel is set to a direction in which the spiral winding of the strands constituting the spiral workpiece is tightened.

(4) The adjustment wheel is rotated forward with respect to the Z-wound spiral workpiece.

(5) The adjustment wheel is reversed with respect to the S-wound spiral workpiece.

(6) After the grinding wheel is cut and fed by a predetermined amount relative to the outer diameter portion of the spiral workpiece, the grinding wheel is fed relatively parallel to the axial direction of the spiral workpiece.

(7) The grinding wheel is fed relatively in parallel to the axial direction of the spiral workpiece while being cut and fed by a predetermined amount relative to the outer diameter portion of the spiral workpiece.

  A centerless grinding apparatus of the present invention is an apparatus suitable for carrying out the above-described centerless grinding method. The centerless grinding apparatus of the present invention is driven by a blade that supports the outer diameter portion of the spiral workpiece and the outer diameter portion of the spiral workpiece. An adjusting wheel for rotating and supporting, a presser rotating means for rotating and supporting the adjusting wheel by pressing the outer diameter portion of the non-grinding portion of the spiral workpiece, a positioning stopper for positioning the axial position of the spiral workpiece, and a rotational drive And a grinding wheel for grinding the outer diameter portion of the spiral workpiece supported and rotated by the adjusting wheel, the blade and the presser rotating means, and a control means for controlling the adjusting wheel and the grinding wheel in conjunction with each other. Thus, the control means and the grinding wheel are controlled in conjunction with each other, and the centerless grinding method is executed.

The following configuration is adopted as a preferred embodiment.
(1) The presser rotating means includes a presser roller that rolls in contact with the outer diameter portion of the non-ground portion of the spiral workpiece with a predetermined pressing force.

(2) The presser roller is disposed at a position as close as possible to the grinding wheel in the axial direction.

  The centerless grinding technique of the present invention was born as a result of various test studies by the present inventors. That is, the present inventor said that the work itself is an assembly of strands, so that it has elasticity in the axial direction, is easily twisted in the rotation direction, and is very easy to bend as a whole work. As a result of repeating various researches and experiments to eliminate the above-mentioned problems, the characteristics of the spiral workpiece that has hindered centerless grinding (weak points) Focusing on the positive use of), we discovered that a spiral workpiece can be made rigid like a normal solid workpiece.

  Then, after further trial and error by the present inventor, the present invention has been completed by improving the structure for rotationally supporting the spiral workpiece in centerless grinding.

  Thus, according to the centerless grinding method of the present invention, the outer diameter portion of the non-grinding portion of the spiral workpiece is supported and rotated by the presser rotating means provided in parallel with the adjusting wheel, the blade and the grinding wheel, and the adjusting wheel and A thrust in the axial positioning stopper direction is applied to the helical work by the presser rotating means, and the helical work is relatively compressed and rigidized by compressing the helical work in the axial direction. By cutting and feeding, the outer diameter part of the spiral workpiece is stepped. By utilizing the characteristics of the spiral workpiece, the outer diameter part of the spiral workpiece is obtained by the in-feed grinding method. Can be stepped.

  That is, in the centerless grinding method of the present invention, the characteristics (weak points) of the spiral workpiece, which has heretofore hindered centerless grinding, are actively used, that is, outside the non-ground portion of the spiral workpiece. The radial part is supported by the adjusting wheel, blade, and presser rotating means and forcedly rotated, so that the skew force acts on the spiral workpiece and the helical workpiece is positioned in the winding direction by utilizing the characteristics that advance in the winding direction. The outer diameter part of the spiral workpiece is rotated in the same manner as a normal solid or hollow cylindrical rigid workpiece, and the outer diameter portion of the spiral workpiece is compressed. Stepping can be performed in the same manner as feed-type centerless grinding.

  According to the centerless grinding method of the present invention, the outer diameter portion of the ultra-low rigidity intravascular medical thin coil (catheter coil) having a diameter of 0.49 mm (element diameter 0.06 mm, double winding coil). It has been experimentally found that grinding is possible.

  In addition, after the grinding wheel is cut and fed (in-feed grinding) by a predetermined amount relative to the outer diameter portion of the spiral workpiece, the grinding wheel is fed relatively parallel to the axial direction of the spiral workpiece. Or by feeding the grinding wheel relatively in parallel to the axial direction of the spiral workpiece while cutting and feeding (infeed grinding) by a predetermined amount relative to the outer diameter portion of the spiral workpiece. By doing so, it is possible to effectively cope with the case where burrs and grinding debris enter between the strands of the spiral workpiece during grinding, the spiral workpiece is extended in the axial direction, and the grinding required part becomes longer.

  In addition, according to the centerless grinding apparatus of the present invention, the above-described centerless grinding method of the present invention can be suitably implemented, and the effects peculiar to the present invention described above can be achieved reliably and easily.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure of the principal part of the centerless grinding apparatus which is Embodiment 1 which concerns on this invention is shown, Fig.1 (a) is a top view, FIG.1 (b) is the front view seen from the pressing roller side. FIG. 2A is a schematic side view of the centerless grinding apparatus in which the adjustment wheel is rotated forward to rotate and support the spiral workpiece, with the grinding wheel omitted from the grinding wheel side. FIG. FIG. 2B shows a state in which the adjusting wheel is inclined. FIGS. 3A to 3C are schematic plan views for explaining a grinding process in the centerless grinding apparatus. The centerless grinding apparatus which is Embodiment 2 which concerns on this invention is shown, it is a side surface schematic diagram which looked at the state which reversely rotates the adjustment wheel and rotationally supports the spiral workpiece, omitting the grinding wheel from the grinding wheel side. 4 (a) shows a state where the presser roller is inclined, and FIG. 4 (b) shows a state where the adjustment wheel is inclined. FIG. 5A to FIG. 5C are plan views showing a centerless grinding apparatus which is still another embodiment of the present invention. FIG. 6A shows a spiral workpiece to be ground by the centerless grinding apparatus of the present invention, FIG. 6A shows the original shape of the spiral workpiece before grinding, and FIG. 6B shows the finished shape of the spiral workpiece after stepping. Each is shown. FIG. 7A to FIG. 7C are plan views each showing a case where a spiral workpiece is stepped by a conventional in-feed grinding centerless grinding apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Throughout the drawings, the same reference numeral indicates the same component or element.

Embodiment 1
A centerless grinding apparatus according to the present invention is shown in FIGS. 1 to 3. Specifically, this grinding apparatus has a spiral workpiece W (element wire w spirally as shown in FIG. 6A). An elastic body structure formed by winding, and the illustrated one is a so-called Z-winding (right-handed spiral workpiece). Stepping is performed by grinding to form a stepped shape as shown in FIG.

  The centerless grinding apparatus shown in the figure includes a grinding wheel 1, an adjustment wheel 2, a blade 3, a presser rotating device (presser rotating means) 4, a positioning stopper 5, and a control device (control means) 6 as main parts.

  As shown in FIGS. 1 and 3, the grinding wheel 1 grinds the outer diameter portion of the spiral workpiece W, and the grinding wheel surface 1 a has a stepped final finished shape of the outer diameter portion of the spiral workpiece W. A cylindrical grindstone surface having a profile corresponding to the above, and a conventionally known general basic structure. That is, the grinding wheel 1 is detachably attached to the grinding wheel shaft 7 and is rotatably supported on a grinding wheel platform (not shown) on which the grinding wheel shaft 7 is fixedly mounted. It is drivingly connected to a driving source such as a driving motor through a mechanism. Further, although not specifically shown, the grinding wheel carriage can be reciprocated in the cutting direction A of the grinding wheel 1 by a cutting device. The driving source of the grinding wheel 1 and the driving source of the cutting device are electrically connected to the control device 6.

  As shown in FIGS. 1 and 3, the adjustment wheel 2 rotatably supports the outer diameter portion of the spiral workpiece W. The adjustment wheel 2 includes a rotation support surface 2a formed of a cylindrical surface, and includes a grinding wheel 1 and a presser rotation described later. It is arranged at a position facing the presser roller 10 of the device 4.

  Further, the adjusting wheel 2 has a conventionally known general basic structure, is detachably mounted and fixed to the adjusting wheel 8, and the adjusting wheel 8 is rotatably supported on the adjusting wheel (not shown). The drive source is connected to a drive source such as a drive motor via a power transmission belt or a gear mechanism, and the drive source is electrically connected to the control device 6.

  As will be described later, the adjusting wheel 2 is rotated in the rotational direction and in the arrangement configuration, and the thrust generated in the helical work W is supported by the positioning stopper due to the rotational support of the helical work W by the cooperative action with the presser rotating device 4. The direction 5 is set, that is, the feed direction B of the spiral workpiece W. Specifically, in the illustrated embodiment, the axis of the adjusting wheel 2, that is, the inclination angle of the adjusting wheel 8 is adjusted in the feed direction B to the spiral workpiece W by the cooperative action with the presser rotating device 4 described later. It is structured to give thrust.

  As shown in FIGS. 1 and 3, the blade 3 supports the outer diameter portion of the spiral workpiece W together with the adjustment wheel 2, and is installed on the adjustment wheel base in the same manner as the adjustment wheel 2. An inclined support surface 3a for supporting the outer diameter portion of the workpiece W from below is provided.

  The inclined support surface 3 a of the blade 3 is set to extend in the axial direction X of the spiral workpiece W from at least the rotation support position of the spiral workpiece W by the presser roller 10 of the press rotating device 4 to the grinding position by the grinding wheel 1. In the illustrated embodiment, it is set so as to extend from the outside of the rotation support position of the spiral workpiece W by the pressing roller 10 to the position of the positioning stopper 5 as shown in FIG.

  The presser rotating device 4 presses the spiral workpiece W against the adjustment wheel 2 to support it, and includes a presser roller 10 as a main part.

  Specifically, the presser roller 10 is configured to be in contact with the outer diameter portion of the non-ground portion of the spiral workpiece W with a predetermined pressing force, and an elastic material such as urethane is preferably used as a constituent material. However, metal rollers can also be used. The specific support structure of the presser roller 10 is rotatably supported by the roller shaft 11 and is brought into rolling contact with the outer diameter portion of the non-ground portion of the spiral workpiece W with a predetermined elastic force by the pressing means 12. ing. In the illustrated embodiment, a bullet biasing means such as a bullet spring is employed as the pressing means 12, and the press roller 10 is constantly bullet biased against the outer diameter portion of the spiral workpiece W.

  The positioning stopper 5 positions the axial position of the spiral workpiece W that is rotationally supported by the adjustment wheel 2, the blade 3, and the pressing roller 10, and is installed at a front position in the feed direction B of the spiral workpiece W. .

  In the positioning stopper 5 of the illustrated embodiment, the tip surface 5a is a positioning contact surface that contacts and locks the tip of the spiral workpiece W. As shown in FIG. 1, the positioning contact surface 5a is a rectangular flat surface. However, although not specifically shown, the positioning contact surface 5a may be in the form of a circular flat surface or a rotation center. .

  Further, in the illustrated embodiment, the main components of the above-described apparatus, particularly the mutual arrangement configuration and drive configuration of the grinding wheel 1, the adjustment wheel 2, and the presser roller 10, are set as follows.

(I) Direction of rotation of the adjusting wheel 2:
The rotation direction of the adjusting wheel 2 is set to a direction in which the spiral winding of the wire w constituting the spiral workpiece W is tightened without being unwound, and in the illustrated embodiment, the grinding object is a so-called Z-wrapped spiral workpiece W. For this reason, the adjustment wheel 2 is rotated forward (rotated in the same direction as the rotation direction of the grinding wheel 1) with respect to the spiral workpiece W (see FIG. 1B).

  By the way, if the rotation direction of the adjustment wheel 2 is the reverse direction (the direction reversed in the present embodiment), the spiral winding of the spiral workpiece W is easy to unwind, and in particular, the spiral workpiece W is a thin strand w. Has been experimentally found to be ungrindable.

(Ii) Positioning relationship of presser roller 10 with respect to spiral workpiece W:
(A) Position where the presser roller 10 is disposed in the direction of the axis X of the spiral workpiece W, that is, the axial rolling contact position P _{X with} respect to the outer diameter portion of the non-ground portion of the spiral workpiece W (FIG. 1A). Is set at a position as close as possible to the grinding wheel 1, and such a configuration is preferable because the rigidity of the spiral workpiece W to be rotationally supported is increased.

(B) The rolling contact position P _{Y in the} circumferential direction of the presser roller 10 with respect to the spiral workpiece W and the presser direction F (see FIG. 1B) take into account the positional relationship with the coordinating adjusting wheel 2. The spiral workpiece W is set so as to be smoothly rotated and supported.

Specifically, the rolling contact position P _Y of the presser roller 10 with respect to the spiral workpiece W is within a predetermined inclination angle α with respect to a horizontal line passing through the axis X of the spiral workpiece W in FIG. In the illustrated embodiment, α is set to 20 ° to 40 °.

(Iii) Inclination of the rotating shafts (adjusting axles, roller shafts) 8 and 11 of the adjusting wheel 2 and the presser roller 10:
By tilting at least one rotation shaft (adjustment wheel shaft, roller shaft) 8, 11 of the adjustment roller 2 and the presser roller 10 of the presser rotation device 4 with respect to the rotation axis X of the spiral workpiece W, the spiral workpiece A configuration is adopted in which a skew force is applied to W to apply a thrust in the feed direction B to the spiral workpiece W.

  That is, in this embodiment, since the rotation direction of the adjustment wheel 2 is normal, the adjustment axle 8 of the adjustment wheel 2 is leveled and the roller of the presser roller 10 as shown in FIG. As shown in FIG. 2 (b), the shaft 11 of the presser roller 10 is made horizontal and the adjustment axle 8 of the adjustment wheel 2 is inclined so that the strands of the spiral workpiece W are aligned. A skew force acts in the winding direction (right-handed screw direction) of w, and thereby a thrust in the feed direction B is generated. It has been experimentally found that the inclination angle β in this case is preferably about 0.5 ° to 1.0 °.

  By adopting such a configuration, the helical work W is forced to rotate by the press roller 10 and the adjustment wheel 2 at the outer diameter portion of the non-grinding portion, so that a skew force acts on the helical work W. As a result of proceeding in the winding direction, the wound strands w, w are tightly engaged and engaged with each other by being compressed in the axial direction by the thrust in the feed direction B due to the skew force and the reaction force from the positioning stopper 5. As a result, the spiral workpiece W is made rigid like the solid or hollow cylindrical workpiece, and is difficult to bend.

  When the adjustment axle 8 of the adjustment wheel 2 or the roller shaft 11 of the presser roller 10 is inclined, the inclination of the roller shaft 11 of the latter presser roller 10 is advantageous in that the adjustment wheel dress at the time of changing the setup becomes unnecessary. There is a point.

  The control device 6 controls each drive source such as the grinding wheel 1 and the adjustment wheel 2 in conjunction with each other. Specifically, the control device 6 is a microcomputer including a CPU, a ROM, a RAM, an I / O port, and the like. It is a configured CNC device. In the control device 6, a control program for executing a grinding process (grinding method) described below is selectively input and set as numerical control data in advance or with a keyboard of an operation panel (not shown).

  Thus, in the centerless grinding device configured as described above, the outer diameter portion of the spiral workpiece W is supported and rotated by the presser roller 10 of the presser rotating device 4 provided in parallel with the adjusting wheel 2, the blade 3 and the grinding wheel 1. At the same time, the adjusting wheel 2 and the presser roller 10 give a thrust to the spiral workpiece W in the axial positioning stopper 5 direction, that is, the feed direction B, thereby compressing the spiral workpiece W in the axial direction and making it rigid. However, the grinding wheel 1 that is rotationally driven at high speed is cut and fed to the outer diameter portion of the spiral workpiece W, and the outer diameter portion of the spiral workpiece W is stepped. Specifically, this grinding process is as follows (see FIG. 3).

(1) As shown in FIG. 1 and FIG. 3A, the spiral workpiece W is supported and rotated by the adjustment wheel 2, the blade 4 and the presser roller 10.

  In this case, the outer diameter portion of the non-grinding portion of the spiral workpiece W is pressed against the adjustment wheel 2 by the presser roller 10, and this portion is forcibly rotated, and the rotation shaft (the adjustment axle of the adjustment roller 2 or the presser roller 10). , Roller shafts) 8 and 11 are inclined (inclination angle β = about 0.5 to 1 °), so that a skew force acts on the spiral workpiece W and a thrust in the feed direction B is generated. The helical work W is compressed in the axial direction to be rigid by the thrust generated by the skew force and the reaction force from the positioning stopper 5, and is difficult to bend.

(2) When the grinding wheel 1 that rotates at a high speed is cut into the spiral workpiece W, burrs and grinding debris enter between the wound strands w and w, and the spiral workpiece W is pivoted. As a result, the corner portion of the grinding wheel 1, that is, the grinding portion (corner portion) of the spiral workpiece W by the edge of the grinding wheel surface 1a is gradually formed into a curved surface having a R-shaped cross section. (The part within the chain line in FIG. 3B).

(3) Subsequently, the grinding wheel 1 is cut while being fed also in the workpiece axis X direction, that is, the grinding wheel 1 is moved with respect to the outer diameter portion of the spiral workpiece W in the step (2). After being cut and fed by a predetermined amount, the spiral workpiece W is fed in parallel in the direction of the axis X of the spiral workpiece W, whereby a curved surface with a large cross-sectional R shape of the grinding portion formed in the step (2) is formed. It is corrected (see FIG. 3C).

  In addition, although not specifically illustrated, as the timing of ending the step (3), for example, marking or the like is performed in advance on the axially finished finishing portion of the spiral workpiece W, which is used as an optical sensor or the like. As the specific means, such as detecting by the above, appropriate means can be adopted.

  In addition, in the step (2), the grinding wheel 1 is preliminarily anticipated that a curved surface having a large cross-section R shape is formed at the grinding portion of the spiral workpiece W by the edge of the grinding wheel surface 1a of the grinding wheel 1. May be sent relatively in parallel to the axial direction of the spiral workpiece while cutting and feeding a predetermined amount relative to the outer diameter portion of the spiral workpiece W.

  As described above in detail, according to the centerless grinding method of the present embodiment, the outer diameter portion of the spiral workpiece W is supported and rotated by the presser rotating device 4 provided in parallel with the adjustment wheel 2, the blade 3 and the grinding wheel 1. At the same time, the adjusting wheel 2 and the presser rotating device 4 apply a thrust to the spiral workpiece W in the direction of the axial positioning stopper 5, thereby skewing the spiral workpiece W and compressing it in the axial direction to make it rigid. However, since the grinding wheel 1 is relatively cut and fed to the outer diameter portion of the spiral workpiece W, the outer diameter portion of the spiral workpiece W is stepped. By utilizing the characteristics, the outer diameter portion of the spiral workpiece W can be stepped by the in-feed grinding method.

  In other words, in the centerless grinding method of the present embodiment, the characteristic (weak point) of the spiral workpiece W that has hindered the centerless grinding has been used positively, that is, non-grinding of the spiral workpiece W. By supporting the outer diameter part of the part with the adjusting wheel 2, the blade 3 and the presser rotating device 4 and forcibly rotating, the skew force acts on the spiral workpiece W and the characteristic of proceeding in the winding direction is used. The spiral workpiece W is pressed against the positioning stopper 5 and compressed, thereby rotating and supporting the spiral workpiece W in a state where the spiral workpiece W is rigidized in the same manner as a normal solid or hollow cylindrical rigid workpiece. The outer diameter portion of W can be stepped in the same manner as normal in-feed centerless grinding.

  By the way, according to the centerless grinding method of the present embodiment, the outer diameter of the ultra-low rigidity intravascular medical thin coil (catheter coil) having a diameter of 0.49 mm (element diameter 0.06 mm, double winding coil). It has been experimentally found that the part can also be ground.

  Further, after the grinding wheel 1 is cut and fed (in-feed grinding) by a predetermined amount relative to the outer diameter portion of the spiral workpiece W, it is fed relatively parallel to the axial direction of the spiral workpiece W. Or by moving the grinding wheel 1 relatively parallel to the axial direction of the spiral workpiece W while cutting and feeding the grinding wheel 1 by a predetermined amount relative to the outer diameter portion of the spiral workpiece W. This makes it possible to cope effectively even when burrs or grinding debris enters between the strands w of the spiral workpiece W during grinding, the spiral workpiece W is stretched in the axial direction, and the part requiring grinding becomes longer. It is.

Embodiment 2
This embodiment is shown in FIG. 4, and is intended for grinding a helical workpiece W having a structure different from that of the first embodiment.

  That is, in the first embodiment, the object to be ground is a so-called Z-winding (right-handed), that is, the wire w is wound in a right-handed spiral shape. A so-called S-wound (left-handed) spiral workpiece W ′ formed by winding the wire w in a left-handed spiral shape is the object to be ground.

  In relation to this, in the present embodiment, the main components of the centerless grinding apparatus, particularly the arrangement and driving configuration of the adjustment wheel 2 and the presser roller 10 are set as follows.

(I) Direction of rotation of the adjusting wheel 2:
The rotating direction of the adjusting wheel 2 is set in a direction in which the spiral winding of the wire w constituting the spiral workpiece W is tightened. In this embodiment, the grinding target is a so-called S-wrapped spiral workpiece W. The adjustment wheel 2 is reversely rotated (rotation in the direction opposite to the rotation direction of the grinding wheel 1) with respect to the spiral workpiece W (rotation in the direction opposite to that in the case of FIG. 1B). .

(Iii) Inclination of the rotating shafts (adjusting axles, roller shafts) 8 and 11 of the adjusting wheel 2 and the presser roller 10:
By tilting at least one rotation shaft (adjustment wheel shaft, roller shaft) 8, 11 of the adjustment roller 2 and the presser roller 10 of the presser rotation device 4 with respect to the rotation axis X of the spiral workpiece W, the spiral workpiece A configuration is adopted in which a skew force is applied to W to apply a thrust in the feed direction B to the spiral workpiece W.

  That is, in this embodiment, since the rotation direction of the adjustment wheel 2 is reverse, as shown in FIG. 4A, the adjustment wheel 8 of the adjustment wheel 2 is horizontal and the roller shaft of the presser roller 10 is set. 11 is inclined (inclination direction is opposite to that in the first embodiment), or as shown in FIG. 4B, the roller shaft 11 of the presser roller 10 is made horizontal and the adjustment axle 8 of the adjustment wheel 2 is adjusted. (Inclination direction is opposite to that in the first embodiment), and a skew force acts on the spiral workpiece W in the winding direction of the wire w (left screw direction). Is configured to occur. It has been experimentally found that the inclination angle β in this case is preferably about 0.5 ° to 1.0 ° as in the case of the first embodiment.

  With this configuration, as in the case of the first embodiment, the spiral workpiece W is compressed in the axial direction by the thrust in the feed direction B due to the skew force and the reaction force from the positioning stopper 5. As a result, the wound strands w and w come into close contact and engagement with each other. As a result, the spiral workpiece W is rigidized in the same manner as a solid or hollow cylindrical rigid workpiece, and is difficult to bend.

Further, when the adjustment axle 8 of the adjustment wheel 2 or the roller shaft 11 of the presser roller 10 is tilted, the tilting of the latter roller shaft 11 of the presser roller 10 is advantageous in that the adjustment wheel dress at the time of changing the setup becomes unnecessary. The point is the same as in the first embodiment.
Other configurations and operations are the same as those of the first embodiment.

  In addition, Embodiment 1 and Embodiment 2 which were mentioned above show the suitable embodiment of this invention to the last, This invention is not limited to this, A various design change is possible in the range.

For example, the modification shown in FIG. 5 is possible.
That is, in the illustrated first and second embodiments, the grinding wheel 1 is configured to be fed in parallel to the axial direction X of the spiral workpiece W. However, as shown in FIG. The spiral workpiece W may move in the axial direction X so that the spiral workpiece W is sent to the grinding wheel 1.

  Further, the centerless grinding technique of the present invention can be used for stepping of a workpiece W such as a thin wire as shown in FIG. 5B in addition to the spiral workpiece W as in the first and second embodiments. Applicable.

  Furthermore, the centerless grinding technique of the present invention is not limited to the case where the outer diameter portion of the one end portion of the spiral workpiece W is subjected to a stepping process as in the above-described embodiment, and as shown in FIG. The present invention can also be applied to the case where stepping processing is performed on the outer diameter portion of the intermediate portion of the workpiece W.

W Spiral workpiece (Z winding) (workpiece)
W 'spiral work (S winding) (workpiece)
w Spiral workpiece strand A Grinding wheel cutting direction B Spiral workpiece feed direction 1 Grinding wheel 1a Grinding wheel surface 2 Adjustment wheel 2a Adjustment wheel rotation support surface 3 Blade 3a Blade tilt support surface 4 Presser rotation Device (presser rotation means)
5 Positioning stopper 5a Positioning contact surface 6 Control device (control means)
7 Grinding wheel shaft 8 Adjustment axle 10 Pressing roller 11 Roller shaft 12 Pressing means

Claims (9)

A centerless grinding method in which stepping is performed on an outer diameter portion of a spiral workpiece formed by spirally winding an element wire,
The outer diameter portion of the non-grinding portion of the spiral workpiece is supported and rotated by a press rotating means arranged in parallel with the adjusting wheel, the blade and the grinding wheel, and the spiral workpiece is axially moved by the adjusting wheel and the press rotating means. By applying a thrust in the direction of the positioning stopper and compressing the helical workpiece in the axial direction to make it rigid, the grinding wheel is relatively cut and fed to the outer diameter part of this workpiece, thereby forming a helical shape. A centerless grinding method for a spiral workpiece, characterized in that stepping is applied to the outer diameter portion of the workpiece. The centerless grinding method for a spiral workpiece according to claim 1, wherein the presser rotating means includes a presser roller that rolls in contact with an outer diameter portion of a non-ground portion of the spiral workpiece with a predetermined pressing force. A skew force is applied to the spiral workpiece by inclining at least one of the rotary shafts of the adjusting wheel and the presser roller of the presser rotating means with respect to the rotational axis of the spiral workpiece. The centerless grinding method for a spiral workpiece according to claim 1, wherein the thrust is applied to the workpiece. 2. The centerless grinding method for a spiral workpiece according to claim 1, wherein the rotation direction of the adjusting wheel is set to a direction in which the spiral winding of the wire constituting the spiral workpiece is tightened. The grinding wheel is cut and fed by a predetermined amount relative to the outer diameter portion of the spiral workpiece, and is then sent relatively parallel to the axial direction of the spiral workpiece. The centerless grinding method of the helical workpiece according to claim 1. The grinding wheel is fed relatively in parallel to the axial direction of the spiral workpiece while being cut and fed by a predetermined amount relative to the outer diameter portion of the spiral workpiece. The centerless grinding method of the helical workpiece according to claim 1. A centerless grinding device that performs stepping processing on the outer diameter portion of a helical workpiece formed by spirally winding an element wire,
A blade that supports the outer diameter of the spiral workpiece;
An adjustment wheel that is rotationally driven and rotationally supports the outer diameter portion of the spiral workpiece;
A presser rotating means for pressing and supporting the outer diameter portion of the non-grinding portion of the spiral workpiece against the adjustment wheel;
A positioning stopper for positioning the axial position of the spiral workpiece;
A grinding wheel that is driven to rotate and grinds the outer diameter portion of the spiral workpiece supported and rotated by the adjusting wheel, the blade, and the presser rotating means;
A control means for controlling the adjusting wheel, the presser rotating means and the grinding wheel in conjunction with each other;
The centerless grinding machine according to claim 1, wherein the control means and the grinding wheel are controlled in conjunction with each other to execute the centerless grinding method according to claim 1. Grinding equipment. 8. The centerless grinding apparatus for a spiral workpiece according to claim 7, wherein the presser rotating means includes a presser roller that rolls in contact with an outer diameter portion of a non-ground portion of the spiral workpiece with a predetermined pressing force. The centerless grinding apparatus for a spiral workpiece according to claim 7, wherein the presser roller is disposed at a position as close as possible to the grinding wheel in the axial direction.

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