JP2005305581A - Method and device for machining valve seat face and valve guide hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for machining a valve seat face and a valve guide hole by which setup changing work can be facilitated and abrasion of a guide bush is reduced. <P>SOLUTION: First/second main spindles are provided on a main spindle head 9 in the Y-axis direction at a prescribed pitch P. A guide hole 30b is machined at the inlet part of the valve guide hole 30a by a rotary tool 18 attached to the first main spindle 12. Simultaneously, chamfering of the front/rear faces 40b, 40c of the valve seat face 40a and rough machining of the valve seat face 40a are executed. Next, finish machining of the valve seat face 40a is executed by matching the rotation center of a blade tool 19 for finishing the valve seat face 40a with the axis line CL of the guide hole 30b, After that, the valve guide hole 30a is finished by guiding a finish reamer 21 to the guide hole 30b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for processing a valve seat surface and a valve guide hole provided in a cylinder head of an automobile engine or the like.

The above-described processing method generally performed in the past is described in FIGS. That is, the valve seat surface and the front and rear relief surfaces are processed by three cutting blades provided on the main shaft, and then the valve guide hole is processed by advancing a reamer provided concentrically with these cutting blades. The reamer is guided by a guide bush.
Patent Document 1 discloses still another processing method. In this method, the relief surface before and after the valve seat surface is processed and the valve seat surface is roughened, then the valve guide hole is reamed and the valve seat surface is finished while the reamer is inserted into the valve guide hole. Processing. The finishing reamer is guided by a guide bush.
Patent Document 2 discloses a method for performing valve guide hole processing and valve seat surface processing while measuring the center of the valve guide hole and correcting the position of the tool based on the measured value.
Japanese Patent Laid-Open No. 6-8021 Japanese Patent Publication No. 9-155611

In processing the valve seat surface and the valve guide hole, functionally, the shaft cores of the valve seat surface and the valve guide hole need to coincide with each other. Therefore, in the thing of the said patent document 1, the clearance gap between a finishing reamer and the guide bush which guides the finishing reamer is made into the very small clearance of 2-5micrometer, and the cutting blade (bite | blade) of valve seat surface processing The finishing reamer (guide bush) is centered with high accuracy with respect to the center of rotation (center of the spindle). When the diameter of the valve guide hole is changed by changing the workpiece, the finishing reamer and the guide bush are replaced (setup change). However, the above-described high centering work is required, and there is a problem that the setup change is troublesome. Also, when the finishing reamer protrudes forward from the guide bush to ream the valve guide hole, there is a slight misalignment between the valve guide hole before processing and the finishing reamer (up to about 0.15μ). Because the shaft center of the finishing reamer swings during machining because of the machining allowance of the finishing reamer and the valve guide hole, in the conventional configuration where the guide clearance between the guide bush and the finishing reamer is very small, the guide bush wears due to the swing. There was also a problem of growing. Moreover, in the method of patent document 2, since the valve guide hole is measured one by one, there is a possibility that the processing time becomes long.
The present invention provides a method for processing a valve seat surface and a valve guide hole that facilitates the above-described setup change work and reduces the wear of the guide bush.

The processing method of the valve seat surface and the valve guide hole in the cylinder head of the present invention is a processing method of the valve seat surface and the valve guide hole of the cylinder head, and includes a cutting tool for chamfering the front and rear surfaces of the valve seat surface and the valve seat surface. Chamfering the front and rear surfaces of the valve seat surface and roughing the valve seat surface with a rotary tool that is integrally equipped with a roughing blade tool and a blade tool for processing the guide hole at the inlet portion of the valve guide hole. After finishing the guide hole of the finishing reamer at the inlet portion of the valve, and then finishing the valve seat surface by aligning the rotation center of the cutting tool for finishing the valve seat surface with the axis of the guide hole, it is provided at the rotation center. The valve guide hole is finished and reamed while the finish reamer inserted through the guide bush is advanced and guided by the guide hole. And wherein the door.
An apparatus for carrying out this method is a cylinder head valve seat surface and valve guide hole processing apparatus, in which a first spindle and a second spindle are mounted in parallel at a predetermined pitch on one spindle head, At the tip of the first spindle, there is provided a rotary tool integrally comprising a blade tool for chamfering the front and rear surfaces of the valve seat surface, a blade tool for roughing the valve seat surface, and a blade tool for machining the guide hole at the inlet portion of the valve guide hole. The tip of the second spindle is provided with a cutting tool for finishing the valve seat surface, and a finishing reamer is provided at the center of the spindle so as to advance and retract in the axial direction via a guide bush, and the spindle head extends in the pitch direction. The column is provided so as to move.

  According to the method of the present application, a guide hole is formed at the valve guide hole inlet with a rotary tool, and at the same time, chamfering of the front and rear surfaces of the valve seat surface and rough processing of the valve seat surface are performed, and then the cutting tool for finishing the valve seat surface is rotated. Finishing the valve seat surface with the axis line aligned with the guide hole, and then finishing the valve guide hole by guiding the finish reamer to the guide hole, the finish reamer (guide bush) and valve seat surface as before Even if the finishing tool is not accurately centered, the concentricity between the valve guide hole finished with the finishing reamer and the valve seat surface can be increased. And since it is not necessary to center the finishing reamer and the finishing blade on the valve seat surface with high accuracy, it is easy to change the finishing reamer when the machining diameter is changed. Furthermore, since it is not necessary to center the finishing reamer and the finishing tool on the valve seat surface with high accuracy, the clearance between the finishing reamer and the guide bush that guides the finishing reamer can be increased. As a result of the gap between the guide bush and the reamer even if there is vibration, the wear of the guide bush is reduced.

  FIG. 1 shows a processing apparatus 1 that processes a valve guide hole 30a and a valve seat surface 40a of a cylinder head W of an automobile or the like concentrically. The valve guide hole 30a is formed in the valve guide 30 that supports the intake valve or the exhaust valve, and the valve seat surface 40a is a valve seat that closes the intake port or the exhaust port and the combustion chamber by the close contact of the intake valve or the exhaust valve. 40. The processing machine 1 will be described. A back-and-forth (Z-axis) moving base 3 is moved on the bed 2 in the Z-axis direction by a Z-axis motor 4 and a feed screw mechanism 5. On the back-and-forth moving base 3, the moving column 6 is moved in the left-right (X-axis) direction (direction orthogonal to the paper surface) by the X-axis motor 7 and the feed screw mechanism 8. A spindle head 9 is guided up and down in the vertical (Y-axis) direction on the front surface of the moving column 6, and is moved up and down by a Y-axis motor 10 and a feed screw mechanism 11. The main spindle head 9 is provided with first and second main spindles 12 and 13 at a predetermined pitch P in the Y-axis direction, and is rotated by a main spindle motor (not shown). The pitch P is set so that the second main shaft 13 does not interfere with the cylinder head W when the first main shaft 12 is processing. At the tip of the first main spindle 12, a guide hole 30b is machined into the blades 14 and 15 for chamfering the front and rear surfaces 40b and 40c of the valve seat surface 40a, the blade 16 for roughing the valve seat surface 40a, and the inlet portion of the valve guide hole 30a. A rotary tool 18 that is integrally provided with a cutting tool 17 is mounted. A cutting tool 19 for finishing the valve seat surface 40a is provided at the tip of the second main shaft 13, and a finishing reamer 21 is provided at the center of the main shaft 13 so as to advance and retreat in the axial direction via the guide bush 20. The guide bush 20 guides the finishing reamer 21 with a larger gap (50 μ) than the conventional one.

  Next, a method of processing the valve guide hole 30a and the valve seat surface 40a of the cylinder head W by the processing machine 1 having the above configuration will be described. The X and Y axis motors 7 and 10 are controlled to move the first main shaft 12 to the first standby position T1 in front of the valve seat 40 to be processed first, as shown in FIG. As shown in FIG. 2B, the first spindle 12 is rotated by a spindle motor (not shown), and the Z-axis motor 4 is controlled to advance the moving base 3 from the first standby position T1. The front and rear surfaces 40b, 40c of the valve seat surface 40a are chamfered by the cutting tools 14, 15, and the valve seat surface 40a is roughly processed by the cutting tool 16, and at the same time, the guide hole of the finishing reamer 21 is formed at the inlet portion of the valve guide hole 30a by the cutting tool 17. 30b is processed. Thereafter, as shown in FIG. 2C, the first step is completed by controlling the Z-axis motor 4 to move the moving base 3 backward to the first standby position T1.

  Next, the Y-axis motor 10 is controlled to move the second main shaft 13 in the Y-axis direction (pitch P direction), and as shown in FIG. It is made to correspond with the axis line CL of the guide hole 30b. As shown in FIG. 3B, the second spindle 13 is rotated by a spindle motor (not shown), and the Z-axis motor 4 is controlled to advance the moving base 3 from the first standby position T1. The valve seat surface 40a is finished by the cutting tool 19. Thereby, the axial center of the valve seat surface 40a coincides with the axial center of the guide hole 30b. Thereafter, as shown in FIG. 3C, the Z-axis motor 4 is controlled to move the moving base 3 to the second standby position T2 so that the blade 19 is separated from the valve seat surface 40a. At the second standby position T2, as shown in FIG. 3D, the finishing reamer 21 inserted through the guide bush 20 provided at the rotation center is advanced. While the reamer 21 is guided to the guide hole 30b via the guide bush 20, the valve guide hole 30a is finished and reamed. Thereby, the valve guide hole 30a coincides with the axial center of the guide hole 30b. When the finish reamer processing is completed, as shown in FIG. 3E, the Z-axis motor 4 is controlled to move the moving base 3 back to the first standby position T1, thereby completing the second step. By repeating the first and second steps, all the valve seat surfaces 40a and the valve guide holes 30a are processed.

  With the above processing, the axis centers of the valve guide hole 30a and the valve seat surface 40a are exactly aligned. However, the finishing reamer 21 in the second step is guided by the guide hole 30b formed in the first step and guided to the guide hole 30b. The center of rotation of the cutting tool for processing the valve seat surface 40a and the center of the finishing reamer 21 are concentric as in the conventional case where the guide bush 20 is guided with high accuracy. Since the degree does not need to be set with high accuracy, the setup change is easy. Further, since the finishing reamer 21 and the finishing blade 19 of the valve seat surface 40a do not have to be centered with high accuracy, the guide bush 20 can guide the finishing reamer 21 with a larger gap than before, and as a result, Even if the finish reamer 21 may shake somewhat during processing, the wear of the guide bush 20 due to this may be reduced.

It is a side view of the processing apparatus which processes the valve guide hole and valve seat surface of the present invention. It is a figure which shows the processing state of a valve guide hole and a valve seat surface with a 1st main axis | shaft. It is a figure which shows the processing state of a valve guide hole and a valve seat surface with a 2nd main axis | shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing apparatus 6 Moving column 9 Main spindle head 12 1st main spindle 13 2nd main spindle 14 Cutting tool 15 Cutting tool 16 Cutting tool 17 Cutting tool 18 Rotary tool 19 Cutting tool 20 Guide bush 21 Finishing reamer 30a Valve guide hole 30b Guide hole 40a Valve seat surface 40b Valve seat Rear face 40c Front face of valve seat surface P Pitch W Cylinder head

Claims (2)

A method of machining a valve seat surface and a valve guide hole of a cylinder head, which includes a cutting tool for chamfering the front and rear surfaces of the valve seat surface, a cutting tool for roughing the valve seat surface, and a cutting tool for machining a guide hole at an inlet portion of the valve guide hole. Chamfering the front and rear surfaces of the valve seat surface, and roughing the valve seat surface, and simultaneously processing the guide hole of the finishing reamer at the inlet portion of the valve guide hole, and then the valve seat surface After finishing the valve seat surface by aligning the rotation center of the cutting tool for finishing machining with the axis of the guide hole, the finish reamer inserted through the guide bush provided at the rotation center is advanced and guided by the guide hole. The valve seat surface and the valve guide hole in the cylinder head are processed by finishing and reaming the valve guide hole. Law. A processing device for a valve seat surface of a cylinder head and a valve guide hole, wherein a first main shaft and a second main shaft are mounted in parallel at a predetermined pitch on one main shaft head, and a valve seat surface is provided at the front end of the first main shaft. A rotary tool that integrally includes a cutting tool for chamfering the front and rear surfaces of the blade, a cutting tool for roughing the valve seat surface, and a cutting tool for processing a guide hole at the inlet portion of the valve guide hole. A cutting tool is provided for finishing the surface, and a finishing reamer is provided at the center of the spindle so as to advance and retreat in the axial direction via a guide bush. The spindle head is provided on the column so as to move in the pitch direction. A device for processing a valve seat surface and a valve guide hole.

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