JP5561220B2 - Metal sealing part processing method and processing apparatus - Google Patents

Description

  The present invention provides a metal seal that closely contacts two members having a tapered seat surface, such as a fuel injection valve, a pressure control valve, or a flow rate control valve used in a fuel injection device or a fuel supply device of an internal combustion engine. The present invention relates to a processing method and a processing apparatus for finishing a sheet surface in a section.

  As an example, a metal seal part structure of a fuel injection valve is shown in FIG. As shown in the enlarged view in the figure, the nozzle portion of the fuel injection valve has a tapered body seat surface 102 on the inner periphery of the tip of the body 101, and the tapered seat surface 104 at the tip of the needle 103. By making the angle formed larger than the angle formed by the body seat surface 102 and making the inclination gentle, the needle edge 105 is seated on the body seat surface 102 and sealed.

Since this metal seal portion structure forms a linear seal at the position where the needle edge 105 abuts, the roundness and surface roughness of the seat surface greatly affect the oil tightness. Therefore, in general, after processing into a predetermined taper shape, finishing of the sheet surface is further performed to improve oil tightness. As a processing method of a metal seal part, for example, in Patent Document 1, a wrap material is interposed between a valve seat surface of a nozzle body and a seating surface of a needle valve tip, and either one of them is rotated, while the other A method of gripping and sliding so as not to rotate is disclosed.

  Further, Patent Document 2 discloses a processing method for forming a seat portion at the tip of a needle seated on a valve seat of a body using a conical grindstone. 9A and 9B, the needle 201 is held at the upper end by the flexible chuck 202, guided by the guide 203, and the tip is opposed to the conical grindstone 204. Yes. The conical grindstone 204 has a conical surface 206 corresponding to the sheet surface 205 of the needle 201, rotates the spindle 207 to give the needle 201 a rotational movement, and the convex portion of the conical surface 206 forms the convex portion of the sheet surface 205. Remove. In addition, the needle 201 and the conical grindstone 204 are separated from each other during processing to change the contact state, thereby reducing uncut residue.

JP-A-60-242956 JP-A-8-105370

  In recent years, the amount of HC discharged from vehicles has become a problem, and regulations tend to be stricter. In particular, in a fuel injection device with high fuel pressure, fuel may leak from the fuel injection nozzle while the engine is stopped, and the oil tightness of the metal seal is further increased to minimize the amount of fuel leakage. Is required. As for control valves used for pressure control and flow rate control in each part of the fuel injection device, it is desired to improve the processing accuracy of the metal seal part in order to improve controllability.

  However, although the method disclosed in Patent Document 1 has an effect of performing sliding in advance in a combination of a needle and a nozzle body of an actual machine and causing both sheet surfaces to come into contact with each other, it is sufficient to improve the roundness of the processed surface. Cannot be obtained. For this reason, it is difficult to satisfy the oil tightness requirement in combinations other than actual machines. Further, as shown in FIG. 8A, since the needle edge 105 is processed in a state of being in pressure contact with the body sheet surface 102, the contact position is cut and the body sheet surface 102 is cut as shown in FIG. 8B. It is easy to make a difference in level. In this case, if the needle rides on the step for some reason and deviates from the original seat position, a gap may be formed and fuel leakage may occur.

  The method disclosed in Patent Document 2 relates to precision finishing (sheet honing) in which a general-purpose grindstone having a tapered grinding surface is pressed coaxially against the tapered surface of a metal seal portion. In this method, since the coaxiality of the needle 201 and the conical grindstone 204 in FIGS. 9A and 9B greatly affects the processing accuracy, high-precision positioning control is required, and the apparatus configuration becomes large. Cheap. Further, in the processing with the conical grindstone 204, the processing position is constant, and when the processing progresses and the convex portion of the conical surface 206 is worn, the roundness and the surface roughness are more difficult to improve. In the method of Patent Document 2, the needle 201 is separated during processing and the needle 201 is separated to change the contact position. However, it takes time and effort to improve roundness and surface roughness. There is a limit.

  Furthermore, in the method of Patent Document 2, it is necessary to prepare and grind each type of grindstone for the needle and the body separately. For example, in a processing apparatus for seat honing, when a nozzle body is to be processed, a work holding collet that holds a nozzle body to be a work is fixed on a pedestal, and a sheet processing grindstone is disposed above the work holding collet. The grindstone is fixed to the tip of the grindstone shaft equipped with a motor, and a high-precision stage that can adjust the grindstone position arbitrarily is used to ensure the coaxiality with the workpiece (for example, 1 μm or less coaxial), and the motor rotates at high speed. (For example, rotation speed 20000 rpm) and processing is performed. Further, a dresser having a variable angle for forming a conical surface of a grindstone and a high-speed rotating motor for driving the dresser are attached.

  Thus, in the conventional processing method, the processing accuracy of the metal seal portion is insufficient, or a large apparatus including an advanced positioning mechanism and a grindstone dresser is required, and the production cost is likely to increase. Accordingly, an object of the present invention is to improve the processing accuracy of the metal seal portion by a simpler method, and to further improve the roundness and the surface roughness, and to ensure oil tightness and prevent fuel leakage and the like. An object of the present invention is to realize a metal seal portion processing method and a processing apparatus capable of preventing and suppressing production costs.

Invention of Claim 1 of this invention is a processing method of the metal seal part which makes the 2nd taper surface formed in the front-end | tip of a shaft member contact the 1st taper surface provided in the body member, The central axis of the shaft member is inclined with respect to the central axis of the body member, and the second tapered surface center is decentered with respect to the first tapered surface center, and the second tapered surface is arranged. A rotating motion for rotating the shaft member around its central axis in a state where loose abrasive grains are interposed between the surface and the first tapered surface, and a pestle for rotating eccentrically around the central axis of the body member When finishing the first taper surface and the second taper surface by applying motion, the first taper surface of the body member and the sheet of the second taper surface of the shaft member The angle difference is defined as the angle difference α and the above body And the central axis of the member, the angle between the center axis of the shaft member, when the eccentric angle beta, the eccentric angle beta is characterized in that set to be smaller than the angle difference alpha.

Invention of Claim 2 of this invention is a processing method of the metal seal part which makes the 2nd taper surface formed in the front-end | tip of a shaft member contact the 1st taper surface provided in the body member, Using the machining member having the second tapered surface having the same shape as the shaft member, the center axis of the machining shaft member is inclined with respect to the central axis of the body member. In addition, the center of the second taper surface is eccentric with respect to the center of the first taper surface, and abrasive grains are interposed between the first taper surface and the second taper surface. Thus, the first tapered surface is finished by applying a rotation motion for rotating the processing shaft member around its central axis and a pestle motion for eccentric rotation about the central axis of the body member. The first member of the body member. The difference in sheet angle between the surface and the second tapered surface of the processing shaft member is defined as an angle difference α, and the angle formed by the central axis of the body member and the central axis of the processing shaft member is deviated. When the center angle β is set, the eccentric angle β is set to be smaller than the angle difference α .

Invention of Claim 3 of this invention is a processing method of the metal seal part which makes the 2nd taper surface formed in the front-end | tip of a shaft member contact the 1st taper surface provided in the body member, Using the processing body member having the first taper surface having the same shape as the body member as the processing object, the central axis of the shaft member is inclined with respect to the central axis of the processing body member. In addition, the center of the second taper surface is eccentric with respect to the center of the first taper surface, and abrasive grains are interposed between the first taper surface and the second taper surface. Thus, the second taper surface is finished by applying a rotation motion that rotates the shaft member around its central axis and a pestle motion that rotates eccentrically around the central axis of the processing body member. At the time of the above processing body member The difference in sheet angle between the first taper surface and the second taper surface of the shaft member is an angle difference α, and the angle formed by the central axis of the processing body member and the central axis of the shaft member is When the eccentric angle β is set, the eccentric angle β is set to be smaller than the angular difference α .

  According to a fourth aspect of the present invention, the abrasive grains are free abrasive grains interposed between the first tapered surface and the second tapered surface. According to a fifth aspect of the present invention, the abrasive grain is an abrasive grain embedded in the first tapered surface of the processing body member or the second tapered surface of the processing shaft member. .

According to a sixth aspect of the present invention, the first taper surface is a tapered seat surface provided on the body member, and the shaft member is the second taper surface on the seat surface. A seat surface having a tapered surface formed at the tip of the valve member is seated and metal sealed.

  According to a seventh aspect of the present invention, the eccentric angle β is set to be larger than the shaft member tilt angle range after the body member and the shaft member are assembled.

According to an eighth aspect of the present invention, there is provided a processing apparatus for processing a metal seal portion in which a second tapered surface formed at a tip of a shaft member is brought into contact with a first tapered surface provided on a body member. There,
A body holding portion for positioning and holding the body member;
A ball member that supports the shaft member in a state in which the shaft member is inclined with respect to the central axis of the body member and the center of the second taper surface is decentered with respect to the center of the first taper surface. A squeezing motion transmitting unit that has a rotating member that rotates eccentrically around the central axis of the body member, and that imparts a squeezing motion to the shaft member;
A holding member attached to the shaft member, and a rotation motion transmitting unit that has a rotating member that rotates the shaft member around the central axis integrally with the holding member, and that rotates the shaft member. It is characterized by providing.

  According to a ninth aspect of the present invention, the first tapered surface is a tapered seat surface provided on the body member, and the shaft member is the second tapered surface on the seat surface. A seat surface having a tapered surface formed at the tip of the valve member is seated and metal sealed.

  According to the first aspect of the present invention, the shaft member and the body member of the metal seal portion are combined, and the shaft member is interposed between the first taper surface and the second taper surface while giving the shaft member a rotation motion and a pruning motion. The operation in which the free abrasive grains are scraped off the convex portion of the contact surface is repeated. The contact position between the first taper surface and the second taper surface is not fixed by the grinding motion, and the processing range is widened and processed uniformly by performing operations in the circumferential direction and the axial direction. Can do. Furthermore, loose abrasive grains can easily enter between the first taper surface and the second taper surface, which promotes processing. Thereby, the effect of improving the roundness and the surface roughness can be obtained, and the processing accuracy can be greatly improved by a simple method.

Therefore, it is applied to the processing of the nozzle portion of the fuel injection valve, and the oil tightness can be improved as compared with the conventional art. Further, since the shaft member and the body member can be finished at the same time, a total-type grindstone adapted to each shape is unnecessary, and the processing time can be shortened. Moreover, it is not necessary to set the concentricity at the time of machining with high accuracy as in the prior art, and a large-scale device equipped with a grinding wheel positioning mechanism, a grinding wheel molding dresser, or the like is not required, so that manufacturing costs can be greatly reduced. .
At this time, since the eccentric angle β of the shaft member with respect to the body member is made smaller than the sheet angle difference α between the tapered surfaces of the two members, the second tapered surface of the shaft member is the first tapered surface of the body member during processing. Will not lift from. Since the finishing process is performed in a state where the entire circumference of the second tapered surface is in contact with the first tapered surface, the entire processed surface can be processed uniformly.

According to a second aspect of the present invention, the body member of the metal seal portion is processed using a processing shaft member having substantially the same shape as the shaft member. The processing method of the present invention has an effect of improving the roundness and surface roughness of each of the shaft member and the body member. On the other hand, for example, only the body member can be processed. In that case, efficient machining is possible by using the other machining shaft member as the other.
At this time, since the eccentric angle β of the machining shaft member with respect to the body member is made smaller than the sheet angle difference α between the tapered surfaces of both members, the second tapered surface of the machining shaft member is 1 is not lifted off the taper surface. Since the finishing process is performed in a state where the entire circumference of the second tapered surface is in contact with the first tapered surface, the entire processed surface can be processed uniformly.

According to a third aspect of the present invention, the shaft member of the metal seal portion is processed using a processing body member having substantially the same shape as the body member. Similarly, only the shaft member can be processed, and a dedicated processing body member can be used, which enables efficient processing.
At this time, since the eccentric angle β of the shaft member with respect to the machining body member is made smaller than the sheet angle difference α between the tapered surfaces of the two members, the second tapered surface of the shaft member is the first of the machining body member during machining. 1 is not lifted off the taper surface. Since the finishing process is performed in a state where the entire circumference of the second tapered surface is in contact with the first tapered surface, the entire processed surface can be processed uniformly.

  A method according to a fourth aspect of the present invention is the method according to the second or third aspect, wherein the first taper surface or the second taper can be easily obtained by interposing a loose abrasive between the first taper surface and the second taper surface. The tapered surface can be processed. Moreover, what integrated the abrasive grain with the shaft member for a process or the body member for a process can also be used, and the same effect is acquired.

  In the method according to claim 6 of the present invention, since the eccentric angle β of the shaft member with respect to the body member is made smaller than the sheet angle difference α between the tapered surfaces of both members, the second tapered surface of the shaft member is processed. Sometimes it does not lift from the first tapered surface of the body member. Since the finishing process is performed in a state where the entire circumference of the second tapered surface is in contact with the first tapered surface, the entire processed surface can be processed uniformly.

  In the method according to claim 7 of the present invention, the eccentric angle β is made larger than the tilt angle range of the shaft member assumed after the assembly of the body member and the shaft member, so that the range wider than the seating range of the body member is set. It can be processed reliably.

  In the apparatus according to claim 8 of the present invention, the body member is held by the body holding portion, and the shaft member is positioned by the ball member of the plowing motion transmission portion. In this state, the ball member is held by the rotating member. Through the shaft member. At the same time, since the rotation member of the rotation movement transmitting portion can rotate the shaft member via the holding member, the combined operation can effectively finish the metal seal portion with a simple configuration.

  As in the ninth aspect of the present invention, the metal seal is preferably formed by seating a tapered seat surface formed at the tip of the valve member on a tapered seat surface provided on the body member. When applied to such a configuration, it is effective for greatly improving the processing accuracy and enhancing the sealing performance of the valve portion.

(A) is a schematic structural drawing of the processing apparatus for demonstrating the processing method of this invention, (b) is the elements on larger scale of (a), (c) is a body expansion view for demonstrating the processing method. (A) is a whole block diagram of the processing apparatus of this invention, (b) is an AA arrow line view of (a). It is. (A) is a longitudinal sectional view showing an overall configuration of a fuel injection valve to which the present invention is applied, (b) is an overall configuration diagram and a partially enlarged view of a needle, and (c) is an overall configuration diagram and a partially enlarged view of a body. FIG. (A), (b) is a figure showing the relationship between the eccentric angle (beta) and the sheet | seat angle difference (alpha), (c) is a figure for demonstrating the sheet | seat angle difference (alpha). (A) is a figure showing the positional relationship of a needle and a body, (b) is a figure for demonstrating the setting range of eccentric angle (beta). (A) is a schematic diagram of a nozzle tip for explaining the effect of the present invention, (b) is a diagram for explaining a conventional machining method, and (c) is a nozzle for explaining a machining position according to the present invention. The expanded sectional view of a front-end | tip part, (d) is the schematic of the body sheet for demonstrating the effect of this invention. (A) is a figure which shows the sheet | seat surface shape of the body processed by the method of this invention, (b) is a figure which shows the sheet | seat surface shape of the needle processed by the method of this invention. (A) is a partial expanded sectional view for demonstrating the nozzle part structure of a fuel injection valve, (b) is a figure for demonstrating the state of the body processing surface by the conventional processing method. (A) is a schematic structural drawing of the processing apparatus for demonstrating the conventional processing method, (b) is the elements on larger scale of (a).

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of an apparatus for explaining the processing method of the present invention, FIG. 2 is an overall configuration diagram of the processing apparatus for realizing the processing method of the present invention, and FIG. It is a figure which shows the nozzle part structure of the fuel injection valve I for gasoline engines as a metal seal part used as a process target. First, the metal seal portion of the fuel injection valve I to which the method of the present invention is applied will be described with reference to FIG. 3A, the fuel injection valve I slidably holds a needle N as a shaft member (valve member) in a cylindrical member H1 fixed to the lower end portion of the cylindrical housing H. A body B as a body member is fixed to the lower end portion of the member H1 to form a fuel injection nozzle.

  The body B has a substantially cylindrical shape, and the tip end portion (lower end portion in the figure) of the needle N is inserted and held in the cylinder. A cylindrical electromagnetic coil H2 is disposed on the outer periphery of the proximal end portion (upper end portion in the drawing) of the needle N, and is connected to an external energization control device via a connector H3 protruding from the outer periphery of the upper end portion of the housing H. Connected. The inside of the cylinder of the housing H serves as a fuel flow path, and the fuel flows into the interior from the external fuel supply passage through the filter member F attached to the upper end opening.

  As shown in FIG. 3 (b), the cylindrical needle N is a fuel flow path that communicates with the inside of the cylinder of the housing H, and the body B passes through a plurality of openings N1 provided in the lower end cylindrical wall. It communicates with the interior space. The upper end portion of the needle N is a large-thickness large-diameter portion N2, and is positioned so as to be slidable with respect to the tubular member H1 to position and hold the needle N. The outer peripheral surface of the tip end portion of the needle N is the second tapered surface, which becomes the seat surface N3, and is processed into a tapered surface shape whose diameter is reduced downward.

  On the other hand, as shown in FIG. 3 (c), the body B has the injection hole plate B1 welded and fixed to the lower end portion thereof, and the lower end inner peripheral surface thereof is a body sheet serving as a first tapered surface and a seating surface. B2 is processed into a tapered surface shape whose diameter is reduced downward. In FIG. 3A, the needle N is urged downward by a spring H4 disposed on the upper end side, and the seat surface N3 at the tip is seated on the body seat B2 to close the fuel flow path. Yes. When the electromagnetic coil H2 is energized, the needle N is driven upwardly against the spring force of the spring H4, the front seat surface N3 is separated from the body seat B2, and fuel is injected.

  At this time, as shown in FIG. 1B, the seat surface N3 of the needle N and the body sheet B2 of the body B have a difference in the angle of the taper surface (sheet angle difference: α). The seat surface N3 is set so as to be slightly inclined with respect to the body seat B2. As a result, a clearance is formed between the needle N and the body sheet B2 on the front end side of the seat surface N3, and the edge portion N4 on the upper end side of the seat surface N3 is seated on the body sheet B2. That is, the seat surface N3 of the needle N forms an annular metal seal portion by contacting the entire periphery of the edge portion N4 with the body sheet B2.

  In order to prevent fuel leakage from the metal seal portion, it is necessary to increase the processing accuracy of the seat surface N3 in the vicinity of the edge portion N4 and the seating range of the edge portion N4 of the body seat B2. Conventionally, the processing of the metal seal part is performed by, for example, grinding the sheet surface N3 of the needle N and the body sheet B2 of the body B in advance to a predetermined taper shape, and then finishing the sheet position. As described above, sheet honing using a general-purpose grindstone has a large apparatus, and there is a limit in improving roundness and surface roughness. Accordingly, the present invention proposes a new method for finishing the sheet surface N3 of the needle N and the body sheet B2 of the body B.

  The basic concept of the processing method of the present invention and the basic structure of the processing apparatus will be described with reference to FIG. In FIG. 1A, the body B is positioned and held by a body holding portion (not shown), and a needle N is inserted into the cylinder of the body B from above. In the method of the present invention, the needle N is disposed so that the central axis thereof is inclined with respect to the central axis of the body B and the seat surface N3 is eccentric with respect to the center of the body sheet B2. The needle N is pressed against the body B1 in an eccentric state by the plowing motion transmission device 1 disposed above, and makes the entire circumference of the seat surface N3 abut on the body sheet B2. At this time, as shown in the development view of the body B in FIG. 1C, the contact shape between the seat surface N3 of the needle N and the body sheet B2 is an elliptical shape that is eccentric with respect to the central axis of the body B. Become.

  The grinding motion transmission device 1 imparts a grinding motion to the needle N, supports the upper end of the needle N, maintains an inclined state, and rotates eccentrically while abutting the seat surface N3 on the body seat B2. . The plowing motion transmission device 1 includes a disk-shaped rotating member 11 that is coaxial with the body B 1, a conical recess 12 provided on the lower end surface of the rotating member 11, an inner end of the needle N that is held in the recess 12. It has a ball member 13 made of a steel ball in contact with the opening, and a spring member 14 that urges the rotating member 11 downward and applies a constant load to the needle N. The rotating member 11 can be rotated around its axis by a driving device (not shown). The recess 12 is formed at a position shifted outward from the center of the disk serving as the rotating member 11, and the ball member 13 held by the recess 12 is pressed against the center of the upper end surface of the needle N by the urging force of the spring member 14. .

  Accordingly, the eccentric amount F from the body B1 on the upper end surface of the needle N is kept constant, and the contact between the seat surface N3 and the body sheet B2 is maintained. When the angle formed by the center axis of the needle N and the center axis of the body B1 is the eccentric angle β, the eccentric angle β <the seat angle difference α with respect to the seat angle difference α shown in FIG. It is better to set so that By making the eccentric angle β smaller than the seat angle difference α, it is possible to suppress the floating of the needle N during processing and improve workability. The setting of the eccentric angle β will be described later.

  At this time, when the rotating member 11 is rotated, the ball member 13 held by the recess 12 rotates eccentrically around the axis of the rotating member 11. Following this, the upper end surface of the needle N makes a circular motion, and the seat surface N3 also rotates eccentrically with respect to the central axis of the body B on the tip side of the needle N. That is, the needle N can be rubbed around the intersection of the center axis of the needle N and the center axis of the body B1 as the rotation center. Moreover, since the needle N is not fixed with respect to the ball member 13, it can rotate freely around its own central axis.

  Therefore, in the method of the present invention, loose abrasive grains are interposed between the sheet surface N3 of the needle N that becomes the metal seal portion and the body sheet B2, and the needle N and the body B are combined as shown in FIG. . Then, while rotating the needle N while applying a constant load for a certain period of time, the rotating member 11 is rotated and rubbed, and the contact surface between the sheet surface N3 and the body sheet B2 is polished by the free abrasive grains. FIG. 1 (c) shows a state where the needle N moves circularly by the scouring motion, and the contact position between the seat surface N3 and the body seat B2 moves while maintaining an elliptical shape.

  As described above, according to the method of the present invention, it is possible to uniformly process a wider range without the contact point being fixed by the pestle movement of the needle N. Further, it has been found that by combining the rotation motion, processing by free abrasive grains is promoted, and by combining these, roundness and surface roughness can be improved as compared with the prior art and desired processing accuracy can be achieved. Although the direction of the rotation motion is not particularly limited, it is preferable that the direction of rotation is opposite to the direction of rotation by the rush motion 1 as shown in FIG. If it does in this way, at the time of a process, it will be estimated that a loose abrasive grain enters a metal seal part easily, and becomes advantageous for progress of a process by a loose abrasive grain.

  FIG. 2 is a configuration example of the lapping apparatus 2 that is a more specific example of the processing apparatus of the present invention. 2 (a) and 2 (b), the wrapping device 2 supports a body holding portion 3 for holding and fixing the body B on the pedestal 21, and supports the needle N with respect to the body B at a predetermined eccentric angle β. A plow motion transmission unit 4 that imparts a saw motion and a rotation motion transmission unit 5 that imparts a rotation motion are provided.

  The body holding unit 3 includes a body positioning jig 31 placed on the base 21, a body receiving jig 32, and a spring 33. The body positioning jig 31 holds the outer periphery of the upper end of the body B with a flange-shaped gripping portion 34 projecting inward from the upper end of the cylindrical body, and the lower end surface of the body B is in the body positioning jig 31. Is supported on a convex disk-shaped body receiving jig 32 accommodated in the body. The spring 33 is interposed between the body receiving jig 32 and the base 21 and urges the body B upward.

  The plowing motion transmission unit 4 includes a plowing motion power motor 41 that generates a driving force for the plowing motion, a plowing motion transmission shaft 42 as a rotating member, and a plowing motion transmission ball that contacts the upper end of the needle N. 43. The plowing motion transmission shaft 42 is positioned coaxially with the body B, and a power transmission gear 44 provided on the upper end surface meshes with a power transmission gear 45 attached to the output shaft of the plowing motion power motor 41. Rotate around the body B axis. A recess (not shown) is formed on the lower end surface of the plowing motion transmission shaft 42 from the center to the outer peripheral side, and the upper half of the plowing motion transmission ball 43 is accommodated and held in the recess as in FIG. ing.

  The needle N includes a front end portion including the seat surface N3 inserted into the body B, and supports the lower end portion of the plowing motion transmission ball 43 in the upper end opening. This support structure is the same as that in FIG. 1 described above, and the eccentric angle β of the needle N is determined by the position of the plowing motion transmission ball 43. In the present embodiment, the spring 33 is disposed on the body B side. However, the urging force of the spring 33 holds the needle N between the body B and the plowing motion transmission ball 43, and the seat surface N3 is the body seat. The structure pressed by B2 is the same. Thereby, the driving force of the plowing motion is transmitted through the plowing motion transmission shaft 42 and the plowing motion transmission ball 43, and the needle N is rotated eccentrically.

  On the other hand, the rotation transmission unit 5 is mounted on the outer periphery of the upper end portion of the needle N, a rotation movement power motor 51 that generates a driving force for rotation, a rotation movement transmission shaft 52 and a rotation movement transmission arm 53 as rotating members. The holding member 54 is used as a holding member. The rotation motion transmission shaft 52 is positioned coaxially with the body B, and is positioned concentrically and independently on the outer periphery of the scraping motion transmission shaft 42. The rotation transmission shaft 52 rotates around the axis of the body B, with the power transmission gear 55 provided on the upper end surface meshing with the power transmission gear 56 attached to the output shaft of the rotation power motor 51. On the lower end surface of the rotation motion transmission shaft 52, a pair of rotation motion transmission arms 53 protrudes downward from two positions which are axially symmetric positions. The circular ring 54 attached to the needle N has a pair of arm portions 57 projecting outward from two locations on the outer peripheral surface, and the pair of rotation motion transmitting arms 53 abut on the pair of arm portions 57. Thus, the kere 54 is rotated.

  As a result, the driving force of the rotation motion is transmitted to the rotation motion transmission shaft 52 and the pair of rotation motion transmission arms 53, and the pair of rotation motion transmission arms 53 rotates the pair of arm portions 57 of the ring 54, thereby Let N rotate. Thus, by employing the wrapping device 2 of the present embodiment, the needle N can be easily provided with a rotation motion and a plowing motion.

  Next, the range of the eccentric angle β (the angle formed by the central axis of the needle N and the body B) will be examined with reference to FIGS. 4 shows the relationship between the eccentric angle β and the seat angle difference α. In FIG. 4C, the seat angle difference α between the seat surface N3 of the needle N and the body seat B2 When expressed using the taper angle η and the taper angle θ of the body sheet B2 of the body B, the angle difference α = (η−θ) / 2. At this time, as shown in FIG. 4 (a), if the angle difference α> the eccentric angle β, the edge portion N4 of the seat surface N3 is seated on the body seat B2 all around, so The contact position can be processed satisfactorily. On the other hand, as shown in FIG. 4B, when the angle difference α is smaller than the eccentric angle β, the edge portion N4 of the needle N is partially lifted as shown in the figure, so that the machining is not established. Therefore, it is preferable to set the eccentric angle β in an angle range smaller than the angle difference α.

  FIG. 5A shows the positional relationship between the needle N and the body B (however, the angle difference α> the eccentric angle β), and the edge of the needle N when the central axes of the needle N and the body B coincide with each other. Points where the part N4 contacts the body B are A and B. Now, assuming that the center axis of the needle N is inclined by an eccentric angle β with respect to the center axis of the body B, the needle N rotates eccentrically with the intersection of both axes as the rotation center F ′, and the edge portion N4 Sit on the body B at A ′ and B ′ (where AB = A′B ′). Here, the center of the needle N is defined as a point O, and the coordinates around this point are considered. If O (0,0), A (r, 0) and B (−r, 0) are set, O (0 , 0), points A ′, B ′, O ′, and F ′ are represented by the coordinates entered in the figure, and O′F ′ = r / a.

  That is, it can be seen that the distance from the rotation center F ′ to the sheet center O ′ is always constant regardless of the eccentric angle β, and the rotation center F ′ varies depending on the eccentric angle β. However, a = tan [(180−θ) / 2)], and θ is the taper angle of the body sheet B2 shown in FIG. The range in which the edge portion N4 of the needle N contacts the body sheet B2, that is, the processing range shown in FIG. 5B is determined according to the eccentric angle β. However, since the needle N has a predetermined clearance on the outer periphery of the large-diameter portion N2 serving as a sliding portion, there is a possibility that the needle N may be slightly tilted after assembly. For this reason, the seating position of the needle N actually changes within a certain seating range due to an inclination determined by the outer peripheral clearance. Therefore, it is desirable to set the eccentric angle β to be larger than the tilt angle range so that the machining range is wider than the seating range in consideration of the tilt angle range.

  The operational effects of the method of the present invention will be described with reference to FIG. FIG. 6B shows a case where the body B is processed by a conventional honing process, and a grindstone 6 having a tapered surface corresponding to the sheet shape of the body B at the tip is used. In the honing process, as shown in the left figure, in order to fix the rotation axis to one axis, it is necessary to ensure the coaxiality at the time of machining with high accuracy. However, even if the grindstone axis coincides with the body axis in a stationary state, if the wobble occurs on the grindstone axis for some reason, the machining position will shift and the shape will be transferred as shown in the right figure. Circularity will decrease.

  On the other hand, in the method of the present invention, as shown in FIG. 6 (a), an automatic centering action is obtained by the pestle movement of the needle N, and uniform processing is possible around the center point of the body sheet B2. It is thought that it becomes. That is, all the deflection and tilt errors of the needle N being processed are converted into fluctuations in the eccentric angle β. Then, with respect to the fluctuation of the eccentric angle β, the position change of the operation center point F ′ is small and F ′ O ′ is constant (see FIG. 5A); for example, the eccentric angle β0.2. The position change amount of the operation center point F ′ at 0.02 is 0.02 μm). At this time, the contact point operation during processing always operates on a certain spherical surface, and the processing surface becomes uniform.

  Therefore, the entire region of the seating range of the needle N can be processed with high accuracy as shown in FIG. At this time, the seat surface N3 of the needle N contacting the body sheet B2 is similarly processed with high accuracy. Further, since the contact point is not fixed, as shown in FIG. 6 (d), there is no step on the processed surface of the body sheet B2, and a gentle R shape is obtained. Thereby, the seat surface N3 of the needle N can be reliably seated on the processed surface of the body seat B2. Thus, the roundness and surface roughness of both the needle N and the body B are improved, the oil tightness can be greatly improved, and fuel leakage from the metal seal portion can be prevented.

  Further, by adopting the lapping device 2 shown in FIG. 2, it is possible to easily give the needle N a rotation motion and a plowing motion. The needle N and the body B can be finished at the same time with a simple configuration, enabling high-precision finishing and reducing the machining time. Since the needle N and the body B have high processing accuracy, it is not always necessary to use a combination of actual machines. Further, unlike a conventional honing device, a general-purpose grindstone, a grindstone positioning mechanism, a grinder shaping dresser, and the like that match each shape are not necessary, so that the manufacturing cost can be reduced.

  FIG. 7 shows a result of actually processing the metal seal portions of the needle N and the body B using the lapping apparatus 2 of FIG. In the figure, a sheet shape and a processed portion after processing according to the present invention are shown. Both the body sheet B2 in FIG. 7 (a) and the sheet portion N3 of the needle N in FIG. 7 (b) have a shape in which the sheet surface has less unevenness than other parts in the processed portion according to the present invention. It can be seen that the surface roughness is improved. Further, when the needle N and the body B processed according to the present invention were assembled in an actual machine and an oil tightness test was performed with an oil tightness measuring machine, the amount of oiltight leakage could be reduced by 70% compared to the conventional case.

  1 and 2, the case where the needle N and the body B are finished at the same time has been described. However, only one of the needle N and the body B can be processed. In this case, the other method is to use the same shape as the processing needle (processing shaft member) or the processing body (processing body member), and use the same device to give the same rotation and plowing motion. Processing can be performed with For example, if it is more efficient to produce the needle and body separately in the production process and separate the finishing process, the finishing process can be performed with high productivity by using the dedicated processing member in this way. It becomes possible to do.

  In this case, as in the above embodiment, in addition to the method of interposing loose abrasive grains, the seat surface of the processing needle (second tapered surface of the processing shaft member) or the seating surface of the processing body (processing) The first tapered surface of the body member may be formed in a grindstone shape by embedding abrasive grains. In this way, the processing can be easily performed by integrating the abrasive grains with the dedicated processing member.

  The method and the processing apparatus of the present invention are not limited to the metal seal portion of the fuel injection nozzle by the needle and body of the fuel injection valve, but various hydraulic controls used in fuel supply devices such as fuel injection devices and fuel pumps of gasoline engines and diesel engines. It is suitably used for metal seal parts such as valves and flow control valves. In addition, it can be used for a metal seal portion used for sealing various high-pressure fluids other than fuel.

I Fuel injection valve B Body (body member)
B1 injection hole plate B2 body sheet (first taper surface, seat surface)
N Needle (shaft member, valve member)
N1 needle (shaft member, valve member)
N2 Large diameter part N3 Sheet surface (second taper surface)
N4 Edge 1 Grinding motion transmission device 11 Disc-shaped rotating member 12 Recess 13 Ball member 14 Spring member 2 Lapping device (processing device)
21 pedestal 3 body holding part 31 body holding part 32 body positioning jig 33 body receiving jig 3 spring 4 plowing movement transmission part 41 plowing movement power motor 42 plowing movement transmission shaft (rotating member)
43 Grinding motion transmission ball (ball member)
44, 45 Power transmission gear 5 Rotation motion transmission part 51 Rotation motion power motor 52 Rotation motion transmission shaft (rotating member)
53 Rotating motion transmission arm 54 Kere (holding member)
55, 56 Power transmission gear 57 Arm

Claims (9)

A method of processing a metal seal portion in which a second taper surface formed at a tip of a shaft member is brought into contact with a first taper surface provided on a body member, wherein the shaft member is in relation to a central axis of the body member And the center of the second taper surface is decentered with respect to the center of the first taper surface, and is separated between the second taper surface and the first taper surface. The first taper surface is obtained by applying a rotation motion for rotating the shaft member around its central axis and a pestle motion for eccentric rotation about the central axis of the body member with abrasive grains interposed therebetween. When finishing the second taper surface, the difference in sheet angle between the first taper surface of the body member and the second taper surface of the shaft member is defined as an angle difference α, and the body The central axis of the member and the shaft member The angle between the axis, when the eccentric angle beta, the processing method of the metal seal part in which the eccentric angle beta is characterized in that set to be smaller than the angle difference alpha. A method of processing a metal seal portion in which a second taper surface formed at a tip of a shaft member is brought into contact with a first taper surface provided on a body member, wherein the body member is to be processed, and the shaft member and Using the machining shaft member having the second tapered surface of the same shape, the center axis of the machining shaft member is inclined with respect to the center axis of the body member, and with respect to the center of the first taper surface. The center of the second taper surface is arranged eccentrically, and the processing shaft member is arranged around the center axis in a state where abrasive grains are interposed between the first taper surface and the second taper surface. The first taper surface of the body member when finishing the first taper surface by applying a rotational motion that rotates the body member and a pestle motion that rotates eccentrically about the central axis of the body member. And the first of the processing shaft member The difference in sheet angle of the taper surface is defined as an angle difference α, and the angle formed between the center axis of the body member and the center axis of the processing shaft member is defined as an eccentric angle β. Is set so as to be smaller than the angle difference α . A method of processing a metal seal portion in which a second taper surface formed at a tip of a shaft member is brought into contact with a first taper surface provided on a body member, the shaft member as a processing target, and the body member and Using a machining body member having a first tapered surface of the same shape, the central axis of the shaft member is inclined with respect to the central axis of the machining body member, and the center of the first tapered surface is The center of the second taper surface is arranged eccentrically, and the shaft member is rotated around its center axis with abrasive grains interposed between the first taper surface and the second taper surface. When the finishing operation of the second taper surface is performed by applying the rotating motion to be performed and the pestle motion to be eccentrically rotated around the center axis of the processing body member, the first body member is processed. Tapered surface and above shaft member When the difference between the sheet angles of the second taper surface is an angle difference α, and the angle between the central axis of the processing body member and the central axis of the shaft member is the eccentric angle β, the eccentricity β A method for processing a metal seal part, wherein the angle β is set to be smaller than the angle difference α .   The method for processing a metal seal part according to claim 2 or 3, wherein the abrasive grains are free abrasive grains interposed between the first tapered surface and the second tapered surface.   The method for processing a metal seal portion according to claim 2 or 3, wherein the abrasive grains are abrasive grains embedded in the first tapered surface of the processing body member or the second tapered surface of the processing shaft member. The first tapered surface is a tapered seating surface provided on the body member, and the seating surface is a tapered surface formed on the tip of the valve member that is the second tapered surface and serves as the shaft member. 6. The method for processing a metal seal part according to claim 1 , wherein the sheet surface is seated and metal sealed . The metal seal portion machining according to any one of claims 1 to 3, wherein the eccentric angle β is set to be larger than the shaft member tilt angle range after the body member and the shaft member are assembled. Method. A processing apparatus for processing a metal seal portion that abuts a second tapered surface formed at a tip of a shaft member on a first tapered surface provided on a body member,
A body holding portion for positioning and holding the body member;
A ball member that supports the shaft member in a state in which the shaft member is inclined with respect to the central axis of the body member and the center of the second taper surface is decentered with respect to the center of the first taper surface. A squeezing motion transmitting unit that has a rotating member that rotates eccentrically around the central axis of the body member, and that imparts a squeezing motion to the shaft member;
A holding member attached to the shaft member, and a rotation motion transmitting unit that has a rotating member that rotates the shaft member around the central axis integrally with the holding member, and that rotates the shaft member. An apparatus for processing a metal seal part, comprising: The first tapered surface is a tapered seating surface provided on the body member, and the seating surface is a tapered surface formed on the tip of the valve member that is the second tapered surface and serves as the shaft member. The metal seal part processing apparatus according to claim 8 , wherein the sheet surface is seated and metal sealed.

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