JP2005120984A - Method of machining valve seat face and valve guide hole of cylinder head, machining tool and machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining tool for a valve seat face and a valve guide hole of a cylinder head, improving the accuracy in concentricity of the valve guide hole to the valve seat face of the cylinder head. <P>SOLUTION: A pilot hole machining tool 21 is provided at the distal end of the machining tool 16, and a rough machining abrasive reamer 22 and a finishing abrasive reamer 23 are provided at the proximal side of the pilot hole machining tool 21. A seat face machining tool 25 is provided at the proximal end of the machining tool 16. A pilot hole 18b is formed in a prepared hole 18a of the valve guide 18 by giving rotation and contouring motion to the pilot hole machining tool 21 while giving rotating motion to the machining tool 16. The eccentricity of the lower hole 18a is corrected to improve the machining accuracy of the pilot hole 18b without causing the decentering of the pilot hole machining tool 21 by tracing the track of the prepared hole 18a during machining work. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a processing method, a processing tool, and a processing apparatus for a valve seat surface and a valve guide hole of a cylinder head.

  The cylinder head of the internal combustion engine is provided with an intake / exhaust valve. The cylinder head is provided with a valve seat, and a cylindrical valve guide is provided concentrically with the valve seat. A valve body that seals the valve seat surface is attached to the valve seat and the valve guide. The valve body includes a stem that is inserted into the valve guide hole and slides along the guide hole, and a flat conical valve head that is connected to the tip of the stem and contacts and separates from the valve seat surface. ing. A valve face provided on the valve head is brought into contact with the valve seat surface with airtightness. The valve seat surface is formed by a seat surface processing tool in a seat surface prepared hole formed in advance in the valve seat. When the valve face is not properly in contact with the valve seat surface, the airtightness in the cylinder is impaired. For this reason, high accuracy is required for the concentricity between the valve guide hole for slidingly guiding the stem and the valve seat surface with which the valve face abuts.

  In order to solve the above problems, a combined machining tool shown in Patent Document 1 has been proposed. This composite machining tool includes a cutter for valve seat surface machining at the tip of a tool body having a tapered portion that engages with a tapered hole formed in a rotating spindle of a machine tool. In addition, the combined machining tool includes a valve guide hole machining reamer capable of moving back and forth in the axial direction with respect to the tool body by the pressure of a coolant supplied to the inside of the tool body via the rotary main shaft. . Further, a blade for pilot hole machining at the time of valve guide hole machining is provided at the tip of the reamer.

A pilot hole that rotates on the same axis with respect to a pilot hole of a valve guide that is formed in advance by a drill or the like, while simultaneously forming a valve seat surface (the contact surface in Patent Document 1) on the valve seat by the cutter of the above-mentioned combined machining tool A pilot hole is formed by a cutting blade. Thereafter, the cutter and the reamer are retracted, the reamer is advanced, and the pilot hole machining blade formed at the tip of the blade is again entered into the pilot hole formed in the valve guide. The following pilot hole is machined to finish the valve guide hole.
JP 2002-126920 A

  In the conventional composite machining tool, the pilot hole is formed concentrically with the valve seat surface because the pilot seat is formed in the pilot guide hole at the same time as the valve seat surface is formed on the valve seat. The For this reason, by first engaging the pilot hole machining blade with the pilot hole, the reamer can be guided along the center axis of the valve guide hole, and the valve guide hole and the seat surface of the valve seat can be guided. The accuracy of concentricity can be improved.

  However, the above-mentioned conventional combined machining tool forms the pilot hole by rotating the pilot hole machining blade to simultaneously contact the entire opening edge of the pilot hole formed in the valve guide, and the following problems arise. It was. When the center axis of the pilot hole formed in the valve guide is in a state of misalignment displaced from the normal center axis, the plurality of pilot hole machining blades start to cut into the opening edge of the pilot hole Since each blade is simultaneously brought into contact with the opening edge, each blade is easily affected by the opening edge in a state of misalignment. That is, since the cutting resistance by each blade varies depending on the circumferential portion of the opening edge, each blade itself is pushed back toward the smaller cutting force and is eccentric, reducing the accuracy of the concentricity of the pilot hole itself with respect to the valve seat surface. To do. As a result, there is a problem that the concentricity cannot be improved even if the tip of the reamer enters the pilot hole with low accuracy of concentricity and finishes the valve guide hole.

  Even if the central axis of the pilot hole formed in the valve guide is on the regular central axis, each blade for pilot hole machining tends to be eccentric when starting cutting into the opening edge of the pilot hole. The accuracy of the pilot hole concentricity is reduced.

  The present invention provides a processing method, a processing tool, and a processing apparatus for a valve seat surface and a valve guide hole of a cylinder head that can improve the accuracy of the concentricity of the valve guide hole with respect to the valve seat surface provided in the cylinder head. It is in.

  In order to solve the above problems, the invention according to claim 1 is characterized in that a seat surface prepared hole formed in advance in a valve seat provided in a cylinder head is finished by a sheet surface processing tool that rotates on the same axis. A seat surface forming step for forming a valve seat surface, and a valve guide hole for forming a valve guide hole by finishing a pilot hole prepared in advance in a valve guide provided in a cylinder head with a reamer that rotates on the same axis. And forming the valve seat surface and the valve guide hole of the cylinder head including the forming step, prior to the valve guide hole forming step, the inner surface of the guide hole pilot hole with respect to the inner peripheral surface on the opening end side. A pilot hole processing tool provided on the same axis as the reamer is brought into contact with the tip by rotating and contouring the reamer shaft by rotating and turning. And summarized in that which is adapted to form a hole.

  According to a second aspect of the present invention, in the first aspect, the pilot hole machining tool is formed concentrically with the inner peripheral corner portion on the opening end side of the pilot hole machined by the pilot hole machining tool. The gist of the invention is to form a taper by rotating and contouring the taper machined part by rotating and turning the reamer shaft.

  According to a third aspect of the present invention, in the second aspect of the present invention, prior to the sheet surface forming step, the tapered portion is rotated and contoured by rotating and turning the reamer shaft with respect to the sheet surface pilot hole. The gist is that the contact portion is formed to form a tapered portion.

The gist of a fourth aspect of the present invention is that, in any one of the first to third aspects, the seat surface forming step and the valve guide hole forming step are performed in the same step.
According to a fifth aspect of the present invention, there is provided a seat surface processing tool for finishing a valve seat surface by rotating contact with a seat surface prepared hole formed in advance on a valve seat provided in the cylinder head on the same axis, and a cylinder head. In the processing tool for the valve seat surface of the cylinder head and the valve guide hole, including a reamer that rotates on the same axis and forms a valve guide hole with respect to a guide hole pilot hole previously formed in the valve guide provided in The gist of the invention is that a pilot hole processing tool having an outer diameter dimension that is connected to the tip of the reamer on the same axis as the reamer and is capable of rotating and contouring inside the guide hole pilot hole is provided. .

The gist of a sixth aspect of the present invention is that, in the fifth aspect, the sheet surface processing tool is formed of a grindstone having an overall outer peripheral surface having a truncated cone shape.
The gist of the invention described in claim 7 is that, in claim 5 or 6, the reamer is an abrasive reamer formed by electrodepositing abrasive grains on the outer peripheral surface of a columnar tool body.

  The invention according to claim 8 is the grindstone tool according to any one of claims 5 to 7, wherein the pilot hole processing tool is formed by electrodepositing abrasive grains on an outer peripheral surface of a columnar tool body. It is a summary.

The gist of the ninth aspect of the present invention is that, in any one of the fifth to eighth aspects, the pilot hole processing tool is a reamer or end mill composed of a plurality of blades.
A tenth aspect of the present invention is the taper reamer portion according to any one of the fifth to ninth aspects, wherein the stepped portion between the pilot hole processing tool and the reamer has a taper reamer portion having a smaller diameter as it goes to the pilot hole processing tool. The gist is that is provided.

  The invention according to claim 11 is the taper processing for chamfering processing according to any one of claims 5 to 10, wherein the tip portion of the pilot hole processing tool has a smaller diameter on the same axis and toward the tip. The gist is that the part is formed.

  A twelfth aspect of the present invention is that, in any one of the seventh to eleventh aspects, the abrasive reamer has a small-diameter coarse finish abrasive reamer positioned on the front end side and a large-diameter dimension positioned on the rear end side. The finishing abrasive grain reamer is used.

Invention of Claim 13 makes it a summary to the sheet surface processing tool which consists of the said abrasive grain reamer and a grindstone in any one of Claims 7-12.
According to a fourteenth aspect of the present invention, the cylinder head support table mounted on the bed and the processing tool according to any one of the fifth to thirteenth aspects are mounted so as to be capable of positive rotation. A spindle device, a contouring motion imparting mechanism that is mounted between the bed and the spindle device and that imparts a contouring motion to the spindle of the spindle device by rotation and turning motion, and before and after moving the support table or the spindle device back and forth And a control device for controlling the operation of the contouring motion imparting mechanism and outputting a control signal for imparting a contouring motion to the machining tool supported by the spindle device. Is the gist.

  According to a fifteenth aspect of the present invention, in the fourteenth aspect, the bed is provided with an X-axis saddle that can reciprocate in the X-axis direction by the X-axis drive mechanism. A Y-axis saddle is installed so as to be capable of reciprocating in the axial direction. A spindle device is installed on the Y-axis saddle, and a control signal is output from the control device to the X-axis drive mechanism and the Y-axis drive mechanism. The gist is that the apparatus is configured to impart a contouring motion.

  According to the invention of claim 1, claim 5 or claim 14, the pilot hole working tool provided coaxially with the reamer is rotated and contoured at the tip of the reamer to rotate the pilot hole and guide hole pilot hole of the valve guide. A pilot hole was formed on the inner peripheral surface of the. For this reason, the contact area of the pilot hole processing tool with respect to the inner peripheral surface of the guide hole pilot hole is reduced, the load resistance during processing work is reduced, and the eccentricity of the pilot hole processing tool itself following the pilot hole is prevented, The accuracy of the concentricity of the pilot hole with respect to the valve seat surface can be improved. Accordingly, the accuracy of the concentricity of the valve guide hole formed by the reamer in the valve guide with respect to the valve seat surface can be improved.

  According to the second or eleventh aspect of the present invention, the taper processed portion formed at the tip end portion of the pilot hole processing tool is applied to the inner peripheral corner portion of the opening edge of the pilot hole, and is chamfered by rotating and contouring. To do. For this reason, when the tip of the reamer is inserted into the pilot hole, there is no contact with burrs or tips, smooth operation is possible, tool wear is reduced, tool life is extended, and valve guide holes are processed more appropriately. And the accuracy of the concentricity can be further improved.

  According to a third aspect of the present invention, in the second aspect, prior to the processing of the valve seat surface by the seat surface processing tool, the tapered portion is applied to the seat surface pilot hole, and the machining allowance at the time of finishing processing is determined by the seat width. The taper machining is performed by rotation and contouring motion so that the thickness is uniform. For this reason, at the time of finishing the valve seat surface by the seat surface processing tool, uneven wear of the tool is eliminated, the tool life is greatly extended, and the accuracy can be improved.

  In the invention according to claim 4 or claim 13, the finishing process of the valve guide hole by the reamer and the finishing process of the valve seat surface by the seat surface processing tool are performed in the same process. For this reason, the accuracy of the concentricity of the valve guide hole with respect to the valve seat surface can be further improved as compared with the method that is performed in a separated manner.

  In the invention according to claim 6, since the seat surface processing tool is formed of a grindstone having a truncated cone shape, high speed rotation is possible by grinding processing, processing time can be shortened and finishing accuracy of the valve seat surface is improved. can do. A conventional blade feeding mechanism or the like is not required, and the structure is simplified.

  According to the seventh aspect of the invention, since the reamer is an abrasive reamer, it can be rotated at a high speed by grinding, the processing time can be shortened, and the finishing accuracy of the valve guide hole can be improved. In addition, the tool life is increased.

  In the invention according to claim 8, since the pilot hole processing tool is a grindstone tool, the processing accuracy of the pilot hole can be improved and the surface of the grindstone tool can be modified and used, so that the tool is frequently replaced. Without it, the tool life can be extended.

According to the ninth aspect of the present invention, since the pilot hole processing tool is a reamer or end mill composed of a plurality of blades, the cutting force is improved and the pilot hole can be efficiently formed.
In the invention according to claim 10, since the taper reamer portion having a smaller diameter toward the tip is provided in the step portion between the pilot hole processing tool and the reamer, the tip of the reamer can smoothly enter the pilot hole. It is possible to improve the processing accuracy of the valve guide hole.

  According to a twelfth aspect of the present invention, the abrasive reamer is composed of a small-diameter coarse finish abrasive reamer located on the front end side and a large-diameter finish abrasive reamer located on the rear end side. For this reason, the finishing process of the valve guide hole can be performed in two stages, the processing load can be reduced, and the finishing process accuracy of the valve guide hole can be improved.

  According to the fifteenth aspect of the present invention, it is easy to use an off-the-shelf machining apparatus by simply changing the software of a control device that outputs a control signal for imparting a contouring motion to the X-axis movement mechanism and the Y-axis drive mechanism Can be manufactured.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of a machining tool and a machining apparatus used in a method for machining a valve seat surface and a valve guide hole of a cylinder head embodying the present invention will be described with reference to the drawings.
As shown in FIG. 2, a table 11 for supporting the cylinder head 17 is provided on the bed 10. A Z-axis saddle 12 is disposed on the bed 10 so as to be movable in the Z-axis (front-rear) direction by a Z-axis drive mechanism (not shown) that constitutes a forward-backward movement mechanism. A columnar X-axis saddle 13 is supported on the Z-axis saddle 12 by an X-axis drive mechanism (not shown) so as to be movable in the X-axis (right and left, orthogonal to the plane of FIG. 2) direction. A Y-axis saddle (not shown) is mounted on the X-axis saddle 13 so as to be movable in the Y-axis (vertical) direction by a Y-axis drive mechanism (not shown). The spindle device 14 is supported on the Y-axis saddle so as to be oriented in the Z-axis direction. A rotating spindle 15 is rotatably supported on the head portion of the spindle device 14, and a tool holder H holding a processing tool 16 is detachably attached to the rotating spindle 15. Then, the Z-axis saddle 12 is moved closer to and away from the cylinder head 17 on the table 11 while the rotation main shaft 15 is rotated in a state where the rotation main shaft 15 is moved to the lower machining position shown in FIG. The cylinder head 17 is subjected to predetermined processing by the processing tool 16.

Next, the structure of the cylinder head 17 processed by the processing tool 16 attached to the rotating spindle 15 will be described.
As shown in FIG. 4, a cylindrical valve guide 18 is fitted and fixed at a predetermined position of the cylinder head 17 by, for example, press-fitting. A cylindrical guide hole pilot hole 18a is formed in advance on the inner peripheral surface of the valve guide 18 by a drill or the like. The cylinder head 17 has a valve seat 19 having a ring shape so as to be positioned on the same axis as the central axis O1 of the valve guide 18 and corresponding to the intake passage 17a for introducing fuel vaporized into the cylinder. Is fitted and fixed by press-fitting, for example. A seat surface lower hole 19 a is formed in advance on the inner peripheral surface of the valve seat 19 opposite to the valve guide 18 when the valve guide 18 is manufactured. In this seat surface prepared hole 19a, for example, as shown in FIG. 5, the first relief surface 19b in an inclined state located on the outer peripheral side as shown in FIG. 5 and the same inclined state located on the inner peripheral side of the first relief surface 19b The second relief surface 19c is formed in advance. A corner portion 19d that rises in a mountain shape is formed at the boundary portion between the two relief surfaces 19b and 19c, that is, at the position where the sheet surface 19f is formed.

Next, the machining tool 16 for finishing the valve guide 18 and the valve seat 19 will be described with reference to FIG.
As shown in FIG. 1, the processing tool 16 is detachably connected to the tool holder H. A pilot hole processing tool 21 is integrally formed at the tip (left side in FIG. 1) of a stainless steel tool body 16a having a cylindrical shape that forms the processing tool 16. The pilot hole processing tool 21 is a grindstone tool configured by attaching abrasive grains in a cylindrical shape by electrodeposition to a small-diameter cylindrical portion at the tip of the tool body 16a. A tapered portion 21a having a smaller diameter at the tip is integrally formed at the tip of the pilot hole processing tool 21. The tapered portion 21a also has abrasive grains attached to the outer peripheral surface of the tapered portion by electrodeposition.

  A rough-finished abrasive reamer for rough-finishing the pilot hole 18a of the valve guide 18 within a predetermined range rearward from the pilot hole processing tool 21 is provided at an intermediate portion of the tool body 16a of the processing tool 16. 22 is formed. A taper reamer portion 22 a having a smaller diameter at the tip is formed at the step portion between the pilot hole processing tool 21 and the rough finish abrasive reamer 22. Similarly, a finishing abrasive reamer 23 is formed in the intermediate portion of the tool body 16a for finishing the rough hole-finished pilot hole 18a within a predetermined range behind the rough finishing abrasive reamer 22. The rough finishing abrasive reamer 22 and the finishing abrasive reamer 23 are configured by attaching abrasive grains in a cylindrical shape to the outer peripheral surface of the tool body 16a by electrodeposition.

  As shown in FIG. 13, the length of the rod portion 26 is such that the processing portion 25a of the sheet surface processing tool 25 processes the sheet surface 19f after the finishing abrasive reamer 23 has completely passed through the entire length of the valve guide hole 18e. Is set to start.

  The outer diameter dimension d1 of the pilot hole processing tool 21, the outer diameter dimension d2 of the rough finishing abrasive grain reamer 22, and the outer diameter dimension d3 of the finishing abrasive grain reamer 23 are in a relation of d1 <d2 <d3. As an example, d1 = 5.0 mm. d2 = 5.9 mm and d3 = 6.0 mm are set.

  A seat for forming a conical valve seat surface 19f (see FIG. 13) having an inclination angle of 45 degrees in the seat surface prepared hole 19a of the valve seat 19 at the base end portion of the tool body 16a of the processing tool 16. The surface processing tool 25 is fitted and fixed. On the outer peripheral surface of the sheet surface processing tool 25, a processing portion 25a having a conical shape as a whole with an inclination angle of 45 degrees is formed. The processed portion 25a is formed by a main body and abrasive grains electrodeposited on the outer peripheral surface thereof. Note that a rod portion 26 where no abrasive reamer is present is provided between the rear edge of the finishing abrasive reamer 23 and the front end surface of the sheet surface processing tool 25.

  A plurality of spiral grooves (not shown) are formed on the outer peripheral surfaces of the rough finishing abrasive reamer 22 and the finishing abrasive reamer 23 to form a discharge path for chips and coolant. Further, although not shown, a coolant supply path is formed inside the processing tool 16 so that the coolant is supplied to the tool surface. Also in the sheet surface processing tool 25, although not shown, a discharge path for chips and coolant is formed on the surface, and coolant is supplied to the tool surface from an internal coolant supply path. The coolant may be water or mist. Further, the coolant may be applied from the outside of the processing tool 16.

Next, a control circuit for controlling the operation of the processing apparatus will be described with reference to FIG.
The control device 31 is provided with a central processing unit (CPU) 32 for performing various arithmetic processing operations. The CPU 32 stores a random access memory (ROM) 33 in which an operation program of the processing device is recorded in advance and various data. Is connected to a random access memory (RAM) 34. The control device 31 has an X-axis linear scale 36 for detecting the position of the machining tool 16 in the X-axis direction, an Y-axis linear scale 37 for detecting the position in the Y-axis direction, and the Z-axis direction via the interface 35. A Z-axis linear scale 38 for detecting the position is connected.

  On the other hand, a plurality of drive circuits 40 are connected to the control device 31 via an interface 39, and an X-axis servo motor 41 for reciprocating the X-axis saddle 13 in the X-axis direction is connected to each circuit 40. Yes. Similarly, a Y-axis servo motor 42 for reciprocating a Y-axis saddle (not shown) in the Y-axis direction is connected to the drive circuit 40. Further, a Z-axis servo motor 43 for driving the Z-axis saddle 12 for feeding and moving the machining tool 16 in the front-rear (Z-axis) direction is connected to the drive circuit 40.

  In the control device 31, the center axis of the rotating processing tool 16 mounted on the rotary spindle 15 using the X-axis servo motor 41 and the Y-axis servo motor 42 is centered on the center axis set in advance at a predetermined position. A contouring motion command section 44 is provided for performing a contouring motion by swiveling.

  Next, the valve guide hole 18e and the valve seat are formed in the pilot hole 18a of the valve guide 18 provided in the cylinder head 17 and the seat surface lower hole 19a of the valve seat 19 using the processing tool 16 and the processing apparatus configured as described above. An operation for finishing the surface 19f will be described.

  First, the X-axis servo motor 41 and the Y-axis servo motor 42 are numerically controlled by a control signal from the control device 31 shown in FIG. 3, and the spindle device 14 including the machining tool 16 is moved in the X and Y axis directions. The center of the spindle is aligned with the center axis O1 when the valve seat surface 19f and the valve guide hole 18e are processed with respect to the cylinder head 17. In this state, the spindle device 14 is moved in the Z-axis direction, and further moved in the X-axis or Y-axis direction to change the central axis O2 of the machining tool 16 from the central axis O1 of the valve guide 18 as shown in FIG. Translate to the offset position. As a result, the tapered portion 21a of the pilot hole processing tool 21 moves to a position corresponding to the corner portion 19d between both relief surfaces 19b and 19c of the valve seat 19, as shown in FIG. In this state, the rotary spindle 15 is rotated to rotate the machining tool 16, and the X-axis servo motor 41 and the Y-axis servo motor 42 are numerically controlled by a control signal output from the contouring motion command unit 44 of the control device 31. To do. Then, the machining tool 16 is swung around the central axis O1 of the valve guide 18 with a predetermined turning radius as shown in FIG. In this state, the Z-axis servo motor 43 is controlled to advance the machining tool 16 in the Z-axis direction, and the taper portion 21a of the pilot hole machining tool 21 chamfers the corner portion 19d between both relief surfaces, thereby forming the taper portion 19e. Form. As a result, the sheet surface 19f can be preprocessed, and the sheet surface processing tool 25 can be ground uniformly without cornering, so that the cutting amount can be reduced.

  Next, the machining tool 16 is returned to the central axis O1 and moved forward to allow the tip of the pilot hole machining tool 21 to enter the opening of the pilot hole 18a of the valve guide 18. Then, with the center axis O1 of the machining tool 16 slightly offset from the center axis O1 of the valve guide 18 as shown in FIG. 7, the pilot hole machining tool 21 is subjected to a contouring motion as shown in FIG. A pilot hole 18b having a predetermined length is formed in the axial direction at the opening edge. Since the pilot hole processing tool 21 performs an accurate circular movement around the center axis O1, even if the pilot hole 18a of the valve guide 18 is in a state of misalignment with respect to the center axis O1, an accurate hole is not followed. It is possible to form the pilot hole 18b that can be processed and whose core misalignment is corrected.

  After the pilot hole 18b is formed, the machining tool 16 is returned to the central axis O1 again, and the machining tool 16 is retracted to set the offset dimension of the central axis O2 from the central axis O1 of the machining tool 16 as shown in FIG. The taper machining part 21a of the pilot hole machining tool 21 is made to correspond slightly to the inner peripheral corner of the opening edge of the pilot hole 18b. In this state, as shown in FIG. 10, the rotating pilot hole machining tool 21 is contoured to chamfer the inner peripheral corner of the opening of the pilot hole 18b by the taper machining part 21a to enter the pilot hole 18b. A tapered portion 18c is formed. Thereby, burrs and corners at the inlet end of the pilot hole 18b are removed.

  Next, as shown in FIGS. 11 and 12, the pilot hole 18b formed in the pilot hole 18a with the center axis O1 of the valve guide 18 and the center axis O2 of the machining tool 16 centered on the same axis again. The pilot hole processing tool 21 and the rough finishing abrasive reamer 22 that rotate on the same axis are entered. Then, the rough finish abrasive reamer 22 sequentially finishes the inner peripheral surface of the pilot hole 18b and the inner peripheral surface of the prepared hole 18a to form a rough finish valve guide hole 18d.

  Finally, as shown in FIGS. 13 and 14, the entire prepared hole 18a of the valve guide 18 is finished by the finishing abrasive reamer 23 of the processing tool 16 rotating on the same axis, thereby forming the valve guide hole 18e. Substantially at the end of the finishing of the valve guide hole 18e, the processed portion 25a of the seat surface processing tool 25 is brought into contact with the tapered portion 19e formed at the corner portion 19d between both relief surfaces of the valve seat 19, and a predetermined angle ( A sheet surface 19f having a predetermined width is formed at 45 degrees.

  According to the processing method, the processing tool, and the processing apparatus for the valve seat surface 19f and the valve guide hole 18e of the cylinder head 17 of the above embodiment, the following effects can be obtained.

  (1) In the above-described embodiment, the pilot hole processing tool 21 is rotated and contoured to form the tapered portion 19e in the pilot hole 19a of the valve seat 19 in advance by the tapered portion 21a. For this reason, the machining allowance at the time of finishing the valve seat surface 19f by the processing portion 25a of the seat surface processing tool 25 becomes uniform with the seat width, the uneven wear of the tool is eliminated, and the tool life is greatly extended. Therefore, the valve seat surface 19f can be smoothly formed by the processing portion 25a of the seat surface processing tool 25, and the processing accuracy of the seat surface 19f can be improved. The cutting portion 25a of the sheet surface processing tool 25 does not hit the burrs or corners, and the cutting amount can be reduced, and the tool life can be maintained long. It is further preferable to form the inclination of the taper machining portion 21a of the pilot hole machining tool 21 at 45 degrees in accordance with the seat surface 19f.

  (2) In the above embodiment, the pilot hole processing tool 21 of the processing tool 16 is rotated and contoured to form the pilot hole 18 b in the pilot hole 18 a of the valve guide 18. Therefore, the pilot hole processing tool 21 partially contacts the inner peripheral surface of the pilot hole 18a to reduce the grinding resistance, and even if the pilot hole 18a has a misalignment, the pilot hole that follows the misalignment of the pilot hole It is possible to eliminate the eccentricity of the processing tool 21 and accurately form the pilot hole 18b in which the core misalignment of the pilot hole 18a is corrected. For this reason, the accuracy of the concentricity between the pilot hole 18b and the seat surface 19f of the valve seat 19 can be improved. Therefore, the abrasive reamers 22 and 23 can be correctly inserted and guided on the central axis O1, the processing accuracy of the valve guide hole 18e by the rough finish abrasive reamer 22 and the finish abrasive reamer 23 can be improved, and the valve guide hole 18e. And the accuracy of the concentricity of the seat surface 19f can be improved.

  (3) In the above embodiment, the tapered portion 18c is formed by rotating and contouring the tapered portion 21a of the pilot hole processing tool 21 at the inner peripheral corner portion of the opening edge of the pilot hole 18b. Further, a taper reamer portion 22 a is provided at the tip of the rough finish abrasive reamer 22. For this reason, the taper reamer 22a provided at the tip of the rough finish abrasive reamer 22 is smoothly cut into the opening edge of the pilot hole 18b, and is further accurately fed and guided to the pilot hole 18b. The valve guide hole 18e can be accurately finished by preventing the eccentricity following the pilot hole 18a.

  (4) In the above embodiment, the valve guide hole 18e is processed by the rough finishing abrasive reamer 22 and the finishing abrasive reamer 23. For this reason, compared with finishing at once, the grinding resistance during processing can be suppressed, the machining allowance by the finishing abrasive reamer 23 can be reduced, the tool life can be improved, and the finishing accuracy of the valve guide hole 18e can be increased. Can be maintained for hours.

  (5) In the above-described embodiment, the finishing abrasive reamer 23 of the processing tool 16 and the sheet surface processing tool 25 are integrally configured, and the finishing process (valve guide hole forming step) of the valve guide hole 18e by the reamer 23, the sheet surface The finishing process (seat surface forming process) of the valve seat surface 19f by the processing tool 25 is performed in the same process. For this reason, the accuracy of the concentricity of the valve guide hole 18e with respect to the valve seat surface 19f can be further improved through the processing tool 16 as compared with a method in which both are separated and performed one after the other.

  (6) In the above embodiment, after the finishing abrasive reamer 23 has completely passed through the entire length of the valve guide hole, the sheet surface processing tool 25 starts processing the sheet surface 19f. By doing so, the processing diameter of the valve guide hole 18e is finished with the same high precision in the length direction without being affected by the wear of the finishing abrasive reamer 23 in the length direction.

In addition, you may change the said embodiment as follows.
The pilot hole processing tool 21 and the taper processing portion 21a may be replaced with abrasive grains, and other tools such as an end mill or a reamer with a plurality of blades may be used. Thereby, cutting force can be improved.

The rough finishing abrasive reamer 22 and the finishing abrasive reamer 23 may be replaced with ordinary reamers that do not use abrasive grains.
(Circle) it is good also as a mechanism which incorporated the said reamer or abrasive grain reamer with respect to the sheet | seat surface processing tool 25 so that advancement / retraction was possible.

A cutter may be used in place of the sheet surface processing tool 25 with abrasive grains.
The rough finish abrasive reamer 22 may be omitted.
The seat surface 19f may be processed on the valve seat 19 by the seat surface processing tool 25 in a state where the finishing abrasive reamer 23 does not completely pass through the valve guide hole 18e.

O You may materialize as a type of processing device which separated sheet surface processing tool 25 from processing tool 16.
O You may form the process part 25a of the sheet surface processing tool 25 in a segment form.

A contouring motion imparting mechanism for causing the machining tool 16 to perform a contouring motion may be configured separately.
O You may actualize to the processing apparatus provided with the mechanism which reciprocates the table 11 to a Z-axis direction.

The front view which shows the processing tool used for the process of the valve seat and valve guide of the cylinder head of this invention. FIG. 6 is a schematic front view showing a cylinder head machining apparatus. FIG. 6 is a control circuit diagram of machining operation of the cylinder head. The longitudinal section showing processing operation of a valve seat of a cylinder head. The partial expanded sectional view of the valve seat of FIG. The expanded cross-sectional view explaining the contouring motion of the pilot hole processing tool of FIG. The longitudinal cross-sectional view explaining the processing operation of the pilot hole of a valve guide. FIG. 8 is an enlarged cross-sectional view illustrating the processing operation of the pilot hole processing tool of FIG. 7. The longitudinal cross-sectional view explaining the chamfering process operation | movement of the opening edge inner periphery of the pilot hole of a valve guide. FIG. 10 is an enlarged cross-sectional view illustrating the processing operation of the pilot hole processing tool of FIG. 9. The longitudinal cross-sectional view explaining the processing operation of the rough finish valve guide hole of a valve guide. FIG. 12 is an enlarged cross-sectional view of the rough finish abrasive reamer of FIG. 11. The longitudinal cross-sectional view for demonstrating the finishing process operation | movement of the valve guide hole of a valve guide, and a valve seat surface. FIG. 14 is an enlarged cross-sectional view through the valve guide and the finishing abrasive reamer of FIG. 13.

Explanation of symbols

  d1, d2, d3 ... outer diameter dimensions, 10 ... bed, 13 ... X-axis saddle, 14 ... spindle device, 16 ... machining tool, 16a ... tool body, 17 ... cylinder head, 18 ... valve guide, 18a ... below guide hole Hole, 18b ... Pilot hole, 18c ... Tapered portion, 19e ... Tapered portion, 18e ... Valve guide hole, 19 ... Valve seat, 19a ... Seat surface lower hole, 19b, 19c ... Relief surface, 19d ... Corner portion, 19f ... Valve Sheet surface, 21 ... Pilot hole processing tool, 21a ... Tapered processing part, 22 ... Rough finishing abrasive reamer, 23 ... Finishing abrasive reamer, 25 ... Sheet surface processing tool, 25a ... Processing part, 31 ... Control device.

Claims (15)

A seat surface forming step of forming a valve seat surface by finishing a seat surface prepared hole formed in advance in a valve seat provided in the cylinder head with a seat surface processing tool that rotates on the same axis;
A valve guide surface of the cylinder head including a valve guide hole forming step in which a valve guide hole is formed by finishing a guide hole pilot hole previously formed in a valve guide provided in the cylinder head with a reamer rotating on the same axis, and In the processing method of the valve guide hole,
Prior to the valve guide hole forming step, a pilot hole processing tool provided on the same axis as the reamer is provided at the tip of the reamer with respect to the inner peripheral surface on the opening end side of the guide hole pilot hole. A method for machining a valve seat surface and a valve guide hole of a cylinder head, wherein a pilot hole is formed by rotating and turning by rotating and swirling movements to make contact. 2. The taper machining portion formed concentrically at the tip of the pilot hole machining tool with respect to the inner peripheral corner on the opening end side of the pilot hole machined by the pilot hole machining tool according to claim 1 And a method of machining a valve seat surface and a valve guide hole of a cylinder head, wherein the taper portion is formed by rotating and contouring contact with each other by turning motion. 3. The taper portion according to claim 2, wherein, prior to the sheet surface forming step, the tapered portion is brought into contact with the lower hole in the sheet surface by rotating and contouring the reamer shaft by rotating and turning. A method for machining a valve seat surface and a valve guide hole of a cylinder head, characterized in that: The method for processing a valve seat surface and a valve guide hole of a cylinder head according to any one of claims 1 to 3, wherein the seat surface forming step and the valve guide hole forming step are performed in the same step. A seat surface processing tool for finishing the valve seat surface by rotating contact on the same axis with respect to a seat surface prepared hole formed in advance in the valve seat provided in the cylinder head;
Cylinder head valve seat surface and valve guide hole machining tool including a reamer that forms a valve guide hole by rotating contact on the same axis with a guide hole pilot hole previously formed in a valve guide provided in the cylinder head In
A pilot hole processing tool having an outer diameter dimension that is connected to the tip of the reamer on the same axis as the reamer and is capable of rotating and contouring inside the pilot hole pilot hole is provided. Machining tool for cylinder head valve seat surface and valve guide hole. 6. The processing tool for a valve seat surface and a valve guide hole of a cylinder head according to claim 5, wherein the seat surface processing tool is formed of a grindstone having an overall outer peripheral surface having a truncated cone shape. 7. The valve seat surface and valve guide hole of a cylinder head according to claim 5, wherein the reamer is an abrasive reamer formed by electrodepositing abrasive grains on the outer peripheral surface of a columnar tool body. Machining tools. 8. The cylinder head according to claim 5, wherein the pilot hole processing tool is a grindstone tool formed by electrodepositing abrasive grains on an outer peripheral surface of a columnar tool body. 9. Machining tool for valve seat surface and valve guide hole. 9. The processing tool for a valve seat surface of a cylinder head and a valve guide hole according to any one of claims 5 to 8, wherein the pilot hole processing tool is a reamer or end mill composed of a plurality of blades. In any 1 paragraph of Claims 5-9, The taper reamer part which becomes small diameter size is provided in the level difference part between the pilot hole processing tool and a reamer, so that it goes to a pilot hole processing tool, It is characterized by the above-mentioned. Machining tool for valve seat surface and valve guide hole of cylinder head. The taper processing part for chamfering which becomes a small-diameter dimension on the same axis line and the front-end | tip part in any one of Claims 5-10 is formed in the front-end | tip part of the said pilot hole processing tool. A cylinder head valve seat surface and valve guide hole machining tool. The abrasive grain reamer according to any one of claims 7 to 11, wherein the abrasive reamer is composed of a small-diameter coarse finish abrasive reamer located on the front end side and a large-diameter finish abrasive reamer located on the rear end side. A cylinder head valve seat surface and a valve guide hole machining tool. The processing of the valve seat surface and valve guide hole of the cylinder head according to any one of claims 7 to 12, wherein the sheet surface processing tool comprising the abrasive reamer and the grindstone is integrally connected. tool. A cylinder head support table installed in the bed;
A spindle device that is mounted on a bed and on which the processing tool according to any one of claims 5 to 13 is rotatably mounted.
A contouring motion imparting mechanism that is mounted between the bed and the spindle device and that imparts a contouring motion to the spindle of the spindle device by rotation and turning motion;
A longitudinal movement mechanism for moving the support table or the spindle device back and forth;
A valve seat for a cylinder head, comprising: a control device that controls the operation of the contouring motion imparting mechanism and outputs a control signal for imparting a contouring motion to a machining tool supported by the spindle device. Surface and valve guide hole processing equipment. 15. The bed according to claim 14, wherein the bed is provided with an X-axis saddle that can be reciprocated in the X-axis direction by an X-axis drive mechanism, and the Y-axis can be reciprocated in the Y-axis direction by the Y-axis drive mechanism. A saddle is installed, and a spindle device is installed on the Y-axis saddle so that a control signal is output from the control device to the X-axis drive mechanism and the Y-axis drive mechanism to impart a contouring motion to the spindle device. An apparatus for processing a valve seat surface of a cylinder head and a valve guide hole.

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