JP2008246638A - Surface treatment method of element for cvt belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently carry out surface treatment of a constricting part on an element for a CVT belt with a cavitation jet. <P>SOLUTION: This method treats a surface of the element 1 for the CVT belt aligned by a neck part 6 extending in the vertical direction against saddle surfaces 11, 12 on side parts of the saddle surfaces 11, 12 to wind a ring 10 around them by placing it on them, forming an R part 16 depressed in an circular arc surface shape from the saddle surfaces 11, 12 on a boundary part of the saddle surfaces 11, 12 and the neck part 6 and adhering them to each other by arranging their postures each other, and the cavitation jet 17 to generate cavitation by a change of pressure accompanying a change of flow velocity is blasted from the side of the saddle surfaces 11, 12 toward a side wall surface 6A of the neck part 6 continued to the R part 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is arranged in an annular form in close contact with each other, and in that state, a ring (sometimes referred to as a hoop) is wound and bound to form a belt for a continuously variable transmission (CVT). In particular, the present invention relates to a treatment method for improving surface hardness, cleaning, and the like.

  A belt-type continuously variable transmission is configured to transmit a torque by applying a compressive force to the belt. For this purpose, the belt has an annular shape with an element that is a metal piece formed in a predetermined shape. It has a structure in which these elements are bound together by a ring. These elements are engaged in close contact with each other in order to maintain a relative position, and a load for binding by the ring acts on the elements. For this reason, if a dimensional difference between the engaging part that connects the elements and the part around which the ring wraps or an error in the contact position with respect to the pulley occurs due to processing errors, the elements regulate their relative positions. In this state, a load for binding by the ring is applied, and the load may become a load for deforming the element.

  For this reason, conventionally, various treatments have been applied to the element in order to increase the strength of the part where the bending load or shearing load acts on the element. For example, in Patent Document 1, in order to increase the toughness, fatigue strength, and impact strength of a curved portion or a corner portion such as a concave portion formed in a base portion of a neck portion in an element, a surface is formed by water jet processing, for example. A method of scraping with a thickness of about 50 μm is described. Patent Document 2 and Patent Document 3 describe a method of performing surface modification of a metal material, a semiconductor material, a metal part, or the like by an impact force generated when a cavitation bubble collapses or crushes, and a method of cleaning. .

JP 2003-56649 A JP 2006-255865 A JP 2000-263337 A

  The water jet process described in Patent Document 1 is a process in which water mixed with glass beads is projected from a nozzle at a high pressure, and the glass beads and their broken pieces collide with an element and scrape the surface. Therefore, in order to perform processing efficiently, it is necessary to project water mixed with glass beads almost vertically onto the processing target site. However, when processing the concave portion formed at the base of the neck portion of the element described above, a portion called a top portion or an ear portion protrudes on the opening side of the concave portion, so that it is substantially perpendicular to the concave portion. Therefore, it is difficult to arrange the nozzles so that the processing cannot be performed efficiently. In addition, a water jet can be projected from the front side or back side of the element to the recess, but in this case, the projection direction is nearly parallel to the surface to be processed, so efficient processing is performed. I can't. In addition, when a plurality of elements are aligned in close contact with each other, and the water jet is projected toward the concave portion in that state, the plurality of elements are arranged even if simultaneous processing is possible. The projection direction of the water jet with respect to the element located in the central portion is closer to parallel with the surface to be processed in the concave portion, and there is a possibility that the processing cannot be performed sufficiently and sufficiently.

  Furthermore, since the glass beads and their broken pieces scrape off the surface of the recesses, dents may be formed on the surface of the recesses, which causes a decrease in the fatigue strength of the element, resulting in an effect of improving the strength of the element. There is a possibility that variations occur and a stable strength improvement effect cannot be obtained. Further, since the glass beads are consumed, there is a disadvantage that the running cost is increased and the burden on the environment is increased.

  On the other hand, in the method using the impact force due to the cavitation bubbles described in Patent Document 2 and Patent Document 3, since a solid such as glass beads is not used, the processing surface facing the release space is processed. However, there is no inconvenience caused by the water jet processing described above. However, conventionally, it has not been sufficiently explored to be applied to the processing or processing of constricted portions such as concave portions in the above-described elements, and there is room for development in this respect.

  The present invention has been made paying attention to the above technical problem, and can effectively perform surface treatment such as improvement of durability and cleaning of an element for a continuously variable transmission (that is, an element for a CVT belt). It is intended to provide a method.

  In order to solve the above problems, the invention of claim 1 is provided with a neck portion extending in a direction perpendicular to the saddle surface on the side portion of the saddle surface on which the ring is placed and wound, CVT belt element for processing the surface of CVT belt element which is formed by forming an R portion that is recessed from the saddle surface in a circular arc shape at the boundary portion with the neck portion and aligned with each other in a posture. In this surface treatment method, a cavitation jet that causes cavitation due to a change in pressure accompanying a change in flow velocity is sprayed from the side of the saddle surface toward the side wall surface of the neck continuous with the R portion. is there.

  According to a second aspect of the present invention, in the first aspect of the invention, the cavitation jet is sprayed on the surface side of the saddle surface and in a direction inclined toward the R portion with respect to the saddle surface. It is the surface treatment method of the element for CVT belts.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the plurality of CVT belt elements are arranged with their postures aligned and in close contact with each other, and in the aligned CVT belt elements. The CVT belt element surface treatment method is characterized in that the cavitation jet is blown toward a side wall surface of the neck portion.

  According to a fourth aspect of the present invention, in the third aspect of the invention, the plurality of parallel CVT belt elements and the cavitation jet are relatively moved in a parallel direction of the CVT belt elements. It is the surface treatment method of the element for CVT belts.

  According to a fifth aspect of the present invention, the nozzle for injecting the cavitation jet is separated from the element for the CVT belt so as to face the side wall surface of the neck portion and to the side thereof. A surface treatment method for a CVT belt element, characterized in that the cavitation jet disposed and guided from the nozzle is guided toward the side wall surface of the neck by a guide member.

  The invention of claim 6 is the invention of claim 3 or 4, wherein the nozzle for injecting the cavitation jet is disposed on the side of the nozzle so as to face the side wall surface of the neck and away from the element for the CVT belt, A slit-shaped passage having an opening cross-sectional shape similar to the continuous surface formed by the side wall surface of the neck portion of the plurality of aligned CVT belt elements, and an inclined guide portion that opens from the slit-shaped passage toward the nozzle. The CVT belt element surface treatment method is characterized in that a cavitation jet jetted from the nozzle is guided toward the side wall surface of the neck by a guide member.

  A seventh aspect of the present invention provides the CVT belt element according to any one of the first to sixth aspects, wherein a carrier flow is caused to flow in a direction intersecting the cavitation jet at a position along the side wall surface of the neck portion. This is a surface treatment method.

  The invention of claim 8 is the surface treatment method of an element for a CVT belt according to the invention of claim 7, wherein the conveying flow is a continuous flow that flows continuously.

  A ninth aspect of the present invention is the surface treatment method for a CVT belt element according to the seventh aspect of the present invention, wherein the carrier flow is an intermittently flowing pulse flow.

  In a tenth aspect of the present invention, a neck portion extending in a direction perpendicular to the saddle surface is provided on a side portion of the saddle surface on which the ring is placed and wound, and the saddle surface extends from the saddle surface at a boundary portion between the saddle surface and the neck portion. In the surface treatment method for a CVT belt element, the surface of the CVT belt element is formed by forming an R portion recessed in an arcuate shape and aligning and aligning with each other. The CVT belt elements are aligned in close contact with each other to form an element row, and the element row is curved at least partially to open the CVT belt element in a fan shape. It is characterized by blowing a cavitation jet that creates cavitation between the belt elements due to changes in pressure accompanying changes in flow velocity. It is a method to.

  The invention of claim 11 is the surface treatment method for an element for a CVT belt according to the invention of claim 10, characterized in that the cavitation jet is blown while the element row is run in the arrangement direction of the elements for the CVT belt. is there.

  The element for a CVT belt targeted by the invention of claim 1 has a neck portion extending in a direction perpendicular to the saddle surface formed on a side portion of the saddle surface on which the ring is placed and wound, and the saddle surface and the neck portion. An R portion that is recessed in a circular arc shape from the saddle surface is formed at the boundary portion. The R portion is a processed portion for preventing stress concentration by making a smooth continuous surface, avoiding breakage and cracking, and improving durability. In the invention of claim 1, a cavitation jet is used to improve the strength of the R portion. The cavitation jet is sprayed from the saddle surface side toward the side wall surface of the neck. In the process, an impact force is generated by cavitation, and this acts on the R portion. In particular, in the first aspect of the invention, even if the R portion is depressed with respect to the saddle surface and the cavitation jet is not sprayed perpendicularly to the surface of the R portion, the impact force generated by crushing or re-expanding the cavitation bubble Since it is radiated in a substantially spherical shape as the center, an impact force can be efficiently applied to the surface of the R portion. Further, the R portion is a portion continuous with the side wall surface of the neck portion, and the cavitation jet is blown toward the side wall surface of the neck portion, so that the pressure gradient in the vicinity of the R portion increases, and as a result, the R portion The generation and crushing of cavitation bubbles and re-expansion occur violently in the vicinity, and a large impact force can be applied to the R portion to efficiently perform the surface treatment of the R portion.

  According to the invention of claim 2, since the cavitation jet can be more concentrated on the R portion, the effect of the surface treatment of the R portion can be improved.

  According to the invention of claim 3, even when the cavitation jet is wider than the thickness of the CVT belt element, that is, the width of the side wall surface of the neck, the CVT belt elements are arranged in a so-called stacked state. Since the surface on which the cavities act is wide, the cavitation jet can be used efficiently, and a plurality of CVT belt elements can be processed simultaneously, so that the processing efficiency can be improved.

  According to the invention of claim 4, in addition to the same effect as that of the invention of claim 3, a large number of CVT belt elements can be processed continuously.

  According to the invention of claim 5 or claim 6, when the cavitation jet is sprayed with the nozzle being separated from the side wall surface of the neck, the cavitation jet diffused before reaching the side wall of the neck is applied to the side wall or the R portion of the neck. Since it can concentrate, processing efficiency can be improved.

  According to the seventh aspect of the present invention, bubbles that cause a buffering action (cushion effect) against the impact force caused by cavitation are eliminated from the vicinity of the side wall surface of the R portion or the neck portion by the conveying flow, so the surface of the R portion Processing efficiency can be improved.

  According to the eighth aspect of the present invention, it is possible to more effectively eliminate bubbles that cause a buffering action (cushion effect) against the impact force caused by cavitation.

  According to invention of Claim 9, since the blowing direction of a cavitation jet can be changed intermittently, the uneven distribution of the location of the impact force by cavitation can be suppressed, and a homogeneous process can be performed.

  According to the tenth aspect of the present invention, even when the CVT belt elements are aligned in the same manner as in the actual use state, the CVT belt elements are curved by being partially bent in the aligned state. Since a cavitation jet is blown on the portion, the residual compressive force on both the front and back surfaces of the CVT belt element can be increased and cleaning can be performed.

  According to the eleventh aspect, in addition to the same effect as the tenth aspect, a large number of CVT belt elements can be continuously processed.

  Next, the present invention will be described more specifically. The material to be treated in the present invention is an element used for a belt of a continuously variable transmission, which is a metal piece formed into a predetermined shape by a processing method such as fine blanking. In particular, the element has a constricted portion where stress tends to concentrate. An example is shown in FIG. The element 1 shown here has a plate portion 2 that is a base portion with both right and left side surfaces tapered, and the left and right side surfaces inclined in a tapered shape are belt winding grooves of the pulley 3. The friction surfaces 4 and 5 transmit torque by frictional contact.

  A neck portion 6 extending upward in the figure is formed at the center portion in the width direction of the plate portion 2. On the upper end portion of the neck portion 6, a top portion 7 extending in an umbrella shape is integrally formed on both sides of the plate portion 2 in the width direction. Therefore, slot portions 8 and 9 opened in the left-right direction are formed between the upper edge portion in the drawing of the plate portion 2 and the lower edge portion in the drawing of the top portion 7. The slot portions 8 and 9 are portions for inserting and holding a ring 10 which is a metal band that annularly binds the elements 1 that are in close contact with each other and are annularly aligned. Upper edge portions are saddle surfaces 11 and 12 with which the ring 10 comes into contact.

  The elements 1 are bound by a ring 10 in an annular arrangement, and are wound around the pulleys 3 on the driving side and the driven side in that state. Therefore, in the state of being wound around the pulley 3, each element 1 needs to expand in a fan shape with respect to the center of the pulley 3 and be in close contact with each other. The portion on the center side in the arrayed state) is formed thin. That is, the thickness is gradually reduced in a state in which the lower portion is scraped off from the portion of the one side of the plate portion 2 (for example, the left side surface in FIG. 6B) lower than the saddle surfaces 11 and 12 by a predetermined dimension. ing. Therefore, when each element 1 spreads and contacts in a fan shape, it contacts in the boundary part from which the board thickness changes. The edge of the boundary portion is a rocking edge 13.

  Each element 1 is formed with a convex portion 14 and a concave portion 15 for determining a relative position. That is, a dimple 14 having a circular cross section that is convex on one surface side (in the example shown, on the surface side where the locking edge 13 is present) is formed at the extended position of the neck portion 6 (or the central portion of the top portion 7). Has been. A bottomed cylindrical hole 15 for loosely fitting (inserting) the dimple 14 in the adjacent element 1 is formed on the surface opposite to the dimple 14. Therefore, when these dimples 14 and the holes 15 are fitted, the relative positions of the elements 1 in the horizontal direction and the vertical direction in FIG. 6A are determined.

  In the element 1 configured as shown in FIG. 6, the vertical position in FIG. 6 is regulated by the dimples 14 and the holes 15, while the saddle surfaces 11 and 12 are applied to the saddle surfaces 11 and 12 by the tension of the ring 10. A downward load is applied. Therefore, when there is a variation in the dimension between the dimple 14 or the hole 15 and the saddle surfaces 11 and 12, a load in the direction of pulling the neck 6 acts. In that case, since the saddle surfaces 11 and 12 extend in a direction perpendicular to the base end portion of the neck portion 6, a bending moment acts between the neck portion 6 and the saddle surfaces 11 and 12. Since the bending moment becomes maximum at the corner portion which is the boundary portion between the neck portion 6 and the saddle surfaces 11 and 12, in order to prevent stress concentration at this portion, as shown in FIG. Are recessed in an arc shape to form a so-called R portion 16. Therefore, the R portion 16 is recessed with respect to the saddle surfaces 11 and 12, and is formed so as to be smoothly continuous with the saddle surfaces 11 and 12 and the side wall surface 6 </ b> A of the neck portion 6. The opening side of the R portion 16 is covered with the top portion 7.

  The R portion 16 is processed together with the element 1 being punched out by press working. In that case, if the surface roughness of the arc surface of the R portion 16 is rough, there is a possibility that cracks may occur due to stress concentration. The surface treatment method according to the present invention is a method of performing treatment such as improving the surface roughness of the inner surface of the R portion, improving the residual compressive stress, and further cleaning the surface of the element 1. The method of the present invention uses a cavitation jet for the surface treatment.

  In a cavitation jet, a high-pressure liquid such as water is jetted from a nozzle, and the gas dissolved in the liquid becomes bubbles or a part of the liquid itself is caused by a pressure drop caused by the speed of the jet flow being increased. Vaporizes to form bubbles, and then the bubbles are crushed due to pressure increase due to a decrease in flow rate, and bubbles are regenerated, and an impact force is generated when the bubbles are generated and crushed or re-expanded. It is a jet. That is, it is a jet whose pressure and jetting speed are controlled so as to positively generate cavitation. This cavitation jet may be injected into the object to be processed in the air, or may be injected in the liquid. In the following example, an example of spraying in liquid is shown. The method using the cavitation jet is different from the method using the water jet described in Patent Document 1 described above, and does not use the impact force caused by the collision of solid objects such as glass beads. It uses the impact force associated with generation and crushing. Therefore, the peening process using the cavitation jet can be referred to as cavitation shotless peening (CSP). In the following description, the cavitation jet is referred to as a CSP jet.

  FIG. 1 schematically shows a state in which the surface treatment of the element 1 is performed by the method according to the present invention, and the elements 1 are aligned in a state in which their postures are aligned and in close contact with each other. This is substantially the same as the state assembled as a belt, and the dimples 14 of the predetermined element 1 are fitted in the holes 15 of the other elements 1 adjacent thereto, and the saddle surfaces 11 and 12 and the neck portion 6 side wall surfaces 6A are closely arranged adjacent to each other to form a substantially continuous surface, and accordingly, the R portion 16 forms a substantially continuous groove.

  The CSP jet 17 is jetted from the nozzle 18 toward the side wall surface 6A of the neck portion 6 constituting a continuous surface as described above. That is, the CSP jet 17 is sprayed on the side wall surface 6 </ b> A of the neck 6. This is performed in a state in which the elements 1 aligned in the posture are submerged in the liquid. The liquid is preferably water (pure water) in terms of handling, availability, cost, and the like, but is not limited thereto. The temperature and pressure of the water may be normal temperature or normal pressure, but if the temperature or pressure rises within a specified range, the treatment efficiency may increase. It is preferable to obtain a suitable water temperature or water pressure.

  The CSP jet 17 is sprayed toward the side wall surface 6 </ b> A along the saddle surfaces 11 and 12. That is, the inside of the slot portions 8 and 9 is sprayed toward the side wall surface 6A. In that case, the nozzle 18 does not need to be perpendicular to the side wall surface 6A of the neck 6, and may be inclined somewhat. In particular, it is preferable to incline toward the inner surface of the R portion 16 in a range where the CSP jet 17 does not interfere with the saddle surfaces 11 and 12 and the top portion 7. This is because the impact force caused by cavitation is concentrated on the R portion 16 as much as possible.

  The injection pressure and flow velocity of the CSP jet 17, the distance between the nozzle 18 and the side wall surface 6 </ b> A, the nozzle diameter, etc. are not only the material of the object to be processed, but also the purpose of the surface treatment such as increasing the residual compressive force and cleaning. It is desirable to determine a suitable value by experiment. In addition, regarding the distance between the nozzle 18 and the side wall surface 6A, as shown in FIG. 2, the R portion 16 which is the processing target portion is recessed from the saddle surfaces 11 and 12, and the lowest bottom surface portion (reference numeral in FIG. 2). In the case of improving the strength of the portion indicated by X, the distance between the bottom surface portion X and the nozzle 18 is somewhat longer than the distance between the side wall surface 6A and the nozzle 18, so that the nozzle is placed on a flat surface such as the side wall surface 6A. The nozzle 18 is brought closer to the side wall surface 6 </ b> A than when processing is performed with the surfaces 18 facing each other. When increasing the residual compressive stress of the R portion 16 in the element 1 made of carbon tool steel, as an example, the injection pressure of the CSP jet 17 is about 30 Mpa, the distance of the nozzle 18 is about 62 mm, and the diameter of the nozzle 18 is about 2 mm. .

  When a large number of elements 1 are arranged in close contact with each other as described above, the length of the groove formed by the R portion 16 becomes larger than the diameter of the CSP jet 17. Are moved relative to each other in the arrangement direction (the thickness direction of the element 1). That is, the spray position of the CSP jet 17 is moved in the arrangement direction of the elements 1. By carrying out like this, the continuous process of many elements 1 can be performed.

  In the process until the CSP jet 17 injected from the nozzle 18 reaches the side wall surface 6A of the neck 6, bubbles are generated due to a pressure drop accompanying an increase in flow velocity. Further, in the vicinity of the side wall surface 6A of the neck 6, the bubbles are crushed or reduced due to an increase in pressure accompanying a decrease in the flow velocity. In particular, in the vicinity of the side wall surface 6A of the neck 6 where the CSP jet 17 collides, the pressure of the CSP jet 17 increases remarkably, and the pressure gradient in this portion increases. As described above, in the CSP jet 17, an impact force is generated in association with the generation of bubbles in the CSP jet, crushing or shrinking, and re-expansion. That is, cavitation occurs. The impact force spreads in all directions centering on the bubbles, but is particularly intense near the side wall surface 6A where the pressure gradient is large. Moreover, the R portion 16 opened in this portion is a so-called narrowed portion, and an impact force acts at an angle close to perpendicular to the entire inner surface.

  As a result, the impact force using a solid material such as the water jet processing described above or an impact force higher than that acts on the R portion 16 to increase the residual compressive stress on the surface of the R portion 16 and adhere to the surface. The impurities that are present can be removed. In that case, since the impact force acting on the R portion 16 is not caused by the collision of the solid, no dent is generated on the surface of the R portion 16. As a result, the fatigue strength of the element 1 can be improved, and variations in fatigue strength can be prevented. In other words, a stable fatigue strength improvement effect can be obtained.

  The CSP jet 17 inevitably spreads after being sent out from the nozzle 18, and the tendency becomes large especially in the liquid. In contrast, the height of the slot portions 8 and 9 in the element 1 (dimension in the direction perpendicular to the saddle surfaces 11 and 12) is low. Furthermore, the nozzle 18 may be spaced apart from the element 1 and arranged on the side thereof in order to secure a distance from the side wall surface 6A of the neck portion 6. Therefore, there is a possibility that a part of the CSP jet 17 does not enter the slot portions 8 and 9 and is not supplied to the vicinity of the R portion 16. In such a case, it is preferable to use a processing container (jig) corresponding to the guide member in the present invention.

  FIG. 3 schematically shows an example of a method using the processing container 19, and the processing container 19 has a volume for accommodating a plurality of elements 1 that are in close contact with each other and aligned in the same posture. And in the location corresponding to one slot part 8 in the element 1 which has lined up internally, the inclination guidance part 20 and the slit-like channel 21 connected to the slot part 8 from the inclination guidance part 20 are formed. . The slit-shaped passage 21 is a passage portion having an opening cross-sectional shape substantially similar to the continuous surface formed by the side wall surface 6 </ b> A of the neck portion 6, and is inclined at the opening end on the side surface side of the processing vessel 19. The guide part 20 is connected. The inclination guide part 20 is a part for converging and guiding the CSP jet 17 sprayed and diffused from the nozzle 18 toward the side wall surface 6A of the neck 6, and therefore, the nozzle from the end of the slit-shaped passage 21. It is formed as an inclined surface that spreads toward 18. Although FIG. 3 shows an example in which the inclined surface spreads up and down, the shape is not limited to these and may be a so-called trumpet shape (conical shape).

  The nozzle 18 is positioned toward the opening end of the slit-shaped passage 21 on the above-described inclination guiding portion 20 side, and the CSP jet 17 is ejected from the nozzle 18. This operation is performed in liquid. Although a part of the CSP jet 17 inevitably spreads radially, the CSP jet 17 flows along the inclined guiding portion 20 and is sent to the slit-shaped passage 21, and further passes through the slot portion 8 of the element 1 to the neck portion 6 side. It reaches the vicinity of the wall surface 6A. In the process, the above-described cavitation occurs, and as a result, the surface treatment of the R portion 16 is performed. Thus, since the CSP jet 17 injected from the nozzle 18 can be sent toward the side wall surface 6A of the neck 6 without waste, the cavitation efficiency can be improved, and the processing efficiency of the element 1 can be improved.

  As described above, the CSP jet 17 may be inclined toward the R portion 16, and in such a case, it is preferable to use the processing container 19 having the configuration shown in FIG. 4. The processing container 19 shown in FIG. 4 increases the inclination angle of one inclined surface 20a constituting the inclination guide part 20 and is retracted into the processing container 19 to a part close to the end part of the top part 7. In addition, the inclination angle of the other inclined surface 20b is reduced. That is, the angle of the inclined surface 20a closer to the nozzle 18 is large, so-called standing, and recedes to the side wall surface 6A side of the neck portion 6. Therefore, the diffused CSP jet 17 can be easily converged toward the slot portion 8, and by retreating, the inclination angle of the CSP jet 17 with respect to the slot portion 8 can be increased without causing interference with the processing vessel 19. Can do. On the other hand, since the angle of the other inclined surface 20b is small and is in a so-called sleeping state, the angle between the streamline of the CSP jet 17 and the inclined surface 20b is relatively small, and in FIG. The CSP jet 17 diffused in the lower side can be efficiently guided toward the slot portion 8 or the side wall surface 6A.

  By the way, cavitation is a phenomenon in which an impact force is generated in association with the generation and crushing or contraction of bubbles, or subsequent re-expansion. In the method of the present invention, the impact force is propagated to the R portion 16 to This is a method of processing. The propagation of the impact force is performed via a fluid interposed between the bubbles and the surface of the R portion 16. If excessive bubbles are included in the fluid used for propagation of the impact force, the bubbles are compressed by the impact force, so that a so-called cushion effect (buffer action) is generated and acts on the surface of the R portion 16. Impact force becomes relatively small. In such a case, the conveyance flow 22 shown by the arrow in FIG. This transport flow 22 is in the vicinity of the R portion 16 and flows in a direction perpendicular to the CSP jet 17 to carry away the remaining bubbles, and the same fluid as the CSP jet 17 is used. The Further, the transport flow 22 can be generated by ejecting a fluid such as low-pressure water from another nozzle (not shown) arranged in a direction orthogonal to the nozzle 18. The pressure and flow velocity are set to such an extent that cavitation by the CSP jet 17 is not hindered, and this can be obtained in advance by experiments. The carrier flow 22 may be a steady flow that is a continuous flow, or may be a pulse flow that flows intermittently.

  If the above-described transport flow 22 is used in combination, the impact force generated by cavitation acts on the R portion 16 without being attenuated, so that the surface treatment of the R portion 16 can be performed efficiently. In addition, when the conveyance flow 22 is a pulse flow, the position at which the CSP jet 17 is sprayed is intermittently changed, so that uneven distribution of the location where the impact force is applied due to cavitation can be prevented or suppressed, and uniform processing can be performed.

  Another example of the processing method of the constriction portion by the CSP jet 17 will be described. As described above, the CVT belt element 1 is used by aligning a large number of the CVT belt elements 1 and using various elements in the manufacturing process. FIG. 5 schematically shows a state in which the element 1 is cleaned by the CSP jet 17, and the guide member 23 is arranged so that the elements 1 aligned with their postures run while maintaining the aligned state. Retained inside. The guide member 23 can be formed of a metal tube, a metal plate, a wire rod, or the like, and a part thereof is configured as a curved path. The curved portion has two types, a first curved portion 23a having a center of curvature on the top 7 side of the aligned elements 1 and a second curved portion 23b having a center of curvature on the opposite side. In any of the curved portions 23a and 23b, the aligned elements 1 are opened in a fan shape. In each of the curved portions 23a and 23b, a nozzle 18 that blows the CSP jet 17 is disposed between the elements 1 opened in a fan shape.

  Many aligned elements 1 are run along the guide member 23 while being held by the guide member 23 shown in FIG. In each of the so-called straight portions between the curved portions 23a and 23b, the elements 1 are in close contact with each other. However, the curved portions 23a and 23b open in a fan shape and have a gap on the side opposite to the center of curvature. A CSP jet 17 is injected from the nozzle 18 toward the gap. As a result, cavitation occurs between the front surface of one element 1 that opens in a fan shape and the back surface of the other element 1, and the impact force associated therewith acts on each element 1. Since such an impact force acts on each traveling element 1 in sequence, the element 1 can be washed continuously. In addition, in the 1st curved part 23a which has a curvature center in the top part 7 side, while the top parts 7 contact, it opens from the opposite side, Therefore The rocking edge 13 mentioned above spaces apart from the adjacent element 1. FIG. Therefore, in the curved portion 23, the CSP jet 17 also acts on the rocking edge 13, and surface treatment such as increasing the residual compressive stress of the rocking edge 13 by the cavitation can be performed.

  Note that the present invention is not limited to the above-described specific example, and the target element is not limited to a configuration having two saddle surfaces. For example, the R portion 16 described above on both sides of one saddle surface. The element for CVT belts of the structure provided with the same R part may be sufficient. Further, in the present invention, the elements may be batch-processed one by one in addition to the batch processing of a plurality of elements.

It is a figure which shows typically the condition which is implementing the method which concerns on this invention. It is the fragmentary figure which expands and shows the II section of FIG. It is a schematic diagram which shows the example which uses the processing container as a guide member. It is a schematic diagram which shows the example which uses the processing container as another guide member. It is a schematic diagram which shows the example in the case of processing the front and back both surfaces of the arranged element. It is a figure which shows an example of an element, Comprising: (A) is a front view, (B) is a side view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Element, 6 ... Neck part, 6A ... Side wall surface, 7 ... Top part, 8, 9 ... Slot part, 10 ... Ring, 11, 12 ... Saddle surface, 13 ... Rocking edge, 16 ... R part, 17 ... CSP jet, DESCRIPTION OF SYMBOLS 18 ... Nozzle, 19 ... Processing container, 20 ... Inclination guide part, 21 ... Slit path, 22 ... Conveyance flow, 23 ... Guide member, 23a ... 1st curved part, 23b ... 2nd curved part.

Claims (11)

A neck portion extending in a direction perpendicular to the saddle surface is provided on the side portion of the saddle surface on which the ring is placed and wound, and the saddle surface and the neck portion are recessed from the saddle surface in a circular arc shape at the boundary portion between the saddle surface and the neck portion. In the surface treatment method for a CVT belt element in which the R portion is formed and the surfaces of the CVT belt elements that are aligned and aligned with each other are aligned,
A surface treatment method for a CVT belt element, characterized in that a cavitation jet that causes cavitation due to a change in pressure associated with a change in flow velocity is blown from the saddle surface side toward a side wall surface of the neck portion that is continuous with the R portion. .   2. The surface treatment method for an element for a CVT belt according to claim 1, wherein the cavitation jet is sprayed on a surface side of the saddle surface and in a direction inclined toward the saddle surface toward the R portion. .   A plurality of the CVT belt elements are arranged so that their postures are aligned and in close contact with each other, and the cavitation jet is sprayed toward the side wall surface of the neck portion of the plurality of aligned CVT belt elements. The surface treatment method for an element for a CVT belt according to claim 1 or 2.   4. The surface treatment method for a CVT belt element according to claim 3, wherein the plurality of aligned CVT belt elements and the cavitation jet are moved relative to each other in the alignment direction of the CVT belt element. .   A nozzle for injecting the cavitation jet is disposed on the side of the nozzle so as to face the side wall surface of the neck and is separated from the element for the CVT belt. The cavitation jet injected from the nozzle is arranged on the side of the neck by the guide member. The surface treatment method for an element for a CVT belt according to any one of claims 1 to 4, wherein the surface treatment is performed toward a wall surface.   The nozzles for injecting the cavitation jets are arranged on the side of the CVT belt elements so as to face the side wall surfaces of the neck portion and are spaced apart from the CVT belt elements, and the side wall surfaces of the neck portions of the aligned CVT belt elements. The guide member having a slit-like passage having an opening cross-sectional shape similar to the continuous surface formed by the nozzle and an inclined guide portion that opens from the slit-like passage toward the nozzle allows the cavitation jet jetted from the nozzle to 5. The surface treatment method for an element for a CVT belt according to claim 3, wherein the surface treatment is performed toward the side wall surface.   The surface treatment method for a CVT belt element according to any one of claims 1 to 6, wherein a carrier flow is caused to flow in a direction intersecting the cavitation jet at a position along the side wall surface of the neck.   The surface treatment method for an element for a CVT belt according to claim 7, wherein the conveying flow is a continuous flow that flows continuously.   The surface treatment method for an element for a CVT belt according to claim 7, wherein the transport flow is a pulse flow that flows intermittently. A neck portion extending in a direction perpendicular to the saddle surface is provided on the side portion of the saddle surface on which the ring is placed and wound, and the saddle surface and the neck portion are recessed from the saddle surface in a circular arc shape at the boundary portion between the saddle surface and the neck portion. In the surface treatment method for a CVT belt element in which the R portion is formed and the surfaces of the CVT belt elements that are aligned and aligned with each other are aligned,
A plurality of the CVT belt elements are arranged with their postures aligned and in close contact with each other to form an element row, and the element row is curved at least partially to open the CVT belt element in a fan shape and open A surface treatment method for a CVT belt element, characterized in that a cavitation jet that causes cavitation due to a change in pressure accompanying a change in flow velocity is sprayed between the CVT belt elements in a portion.   11. The surface treatment method for a CVT belt element according to claim 10, wherein the cavitation jet is blown while the element row is caused to travel in the arrangement direction of the CVT belt elements.

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