JP2006263843A - Dressing device, grinding device, dressing method, numerical control program and dresser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dressing device and a dressing method, keeping the length of a generating line of a cylindrical surface to a predetermined length even when dressing a slant in an inner surface grinding wheel having a slat and a cylindrical surface. <P>SOLUTION: One end of the cylindrical surface 32 is provided with a step part, whereby the cylindrical surface 35 is formed of a first cylindrical surface 35 and a second cylindrical surface 36 having a smaller outline than the first cylindrical surface 35. When dressing the slant 31, the cylindrical surface 32 is dressed including the step part to form the cylindrical surface 32a without a step. Thus, every time the slant 31 is dressed, the cylindrical surface 32 is formed so that the generating line of the first cylindrical surface 35 is L, whereby the length of part grinding a first inside diameter surface (that is, the length of the generating line of the first cylindrical surface 35) can be kept to a fixed value L. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dressing device, a grinding device, a dressing method, a numerical control program, and a dresser, and for example, relates to dressing a grindstone for grinding an inner surface of a fuel injection nozzle.

A fuel injection nozzle used in a diesel engine or the like is a component that adjusts the fuel injection amount, and therefore requires high machining accuracy.
Therefore, in order to increase the processing accuracy, the inner surface of the fuel injection nozzle is roughly processed by a lathe or the like, and then subjected to finishing by performing internal grinding with a numerically controlled internal grinding device.

FIGS. 7A to 7C are views for explaining the relationship between the fuel injection nozzle (workpiece) and the internal grinding wheel (hereinafter, grindstone).
FIG. 7A shows a cross section of the fuel injection nozzle 2. For example, the axial length is about 50 [mm], the outer diameter is about 10 [mm], and the inner diameter is about 6 [mm]. A cylindrical member 41 is used.
A metal material such as iron or stainless steel is used as a member constituting the fuel injection nozzle 2.

The front end side of the cylindrical member 41 is closed, and a protruding portion 45 having a hemispherical shape is formed at the front end portion.
A plurality of fine injection ports (not shown) for injecting fuel are formed in the protrusion 45, and these injection ports penetrate the tip portion inside the cylindrical member 41.

The inside of the cylindrical member 41 is hollowed out in a cylindrical shape to form an inner diameter surface. The inner diameter surface is composed of a first inner diameter surface 44 formed on the opening end side and a second inner diameter surface 43 formed on the closed end side, and the inner diameter of the first inner diameter surface 44 is the second inner diameter surface. It is larger than the inner diameter of 43.
A cylinder member called a needle is inserted into the fuel injection nozzle 2 in a diesel engine, but the first inner diameter surface 44 forms a sliding surface with the column member, so that high processing accuracy is required. The

  The closed end side of the inner diameter surface is narrowed in a funnel shape to form a nozzle sheet surface 42. The tip of the cylindrical member inserted into the fuel injection nozzle 2 has a conical shape similar to the shape of the nozzle seat surface 42, and the fuel injection amount is adjusted by the size of the gap with the nozzle seat surface 42. . For this reason, the nozzle sheet surface 42 is also required to have a high processing accuracy like the first inner diameter surface 44.

  As described above, since the first inner diameter surface 44 and the nozzle sheet surface 42 require high processing accuracy, these portions are subjected to inner surface grinding by an inner surface grinding device to ensure desired processing accuracy.

  Although it is possible to grind the first inner diameter surface 44 and the nozzle sheet surface 42 using individual grindstones, in order to improve processing efficiency and cost efficiency, a circle formed with a conical slope at the tip Grinding both the first inner diameter surface 44 and the nozzle sheet surface 42 using a columnar grindstone is performed.

FIG. 7B shows the positional relationship between the fuel injection nozzle 2 and the grindstone 8 when the nozzle sheet surface 42 is ground with the grindstone 8 having a conical slope and a cylindrical surface.
When grinding the nozzle sheet surface 42, the nozzle sheet surface 42 is cut by the slope of the grindstone 8 as shown in FIG. 7B while rotating the grindstone 8 and the fuel injection nozzle 2 about the central axis. The nozzle sheet surface 42 is ground.

FIG. 7C shows the positional relationship between the fuel injection nozzle 2 and the grindstone 8 when grinding the first inner diameter surface 44 with the grindstone 8.
As shown in the figure, when grinding the first inner diameter surface 44, the first inner diameter surface 44 is cut by the cylindrical surface of the grindstone 8 while rotating the grindstone 8 and the fuel injection nozzle 2 around the central axis, respectively. The first inner surface 44 is ground. In addition, grinding is performed over all the inner peripheral surfaces of the first inner diameter surface 44 by moving the grindstone 8 back and forth in the direction of the central axis.

As a technique relating to the internal grinding of the fuel injection nozzle, there are an internal grinding method and apparatus and a fuel injection nozzle manufacturing method disclosed in the following document.
JP 11-277383 A

  This document discloses a method of grinding a nozzle sheet portion and an inner diameter surface of a fuel injection nozzle using a grindstone having a slope and a cylindrical surface.

As the grinding wheel 8 is ground, clogging or dropping of abrasive grains occurs. Therefore, it is necessary to restore the state of the surface of the grinding wheel 8 by dressing occasionally (that is, by shaving the surface).
However, when the grindstone slope is dressed, there is a problem that the length of the bus bar on the cylindrical surface is shortened.

FIG. 8 shows a state where the slope 31 a is formed by dressing the slope 31 of the grindstone 8.
As shown in the figure, the length of the generatrix of the cylindrical surface 32 before dressing is L, but when dressed to form the slope 31a, the length becomes L1 (<L), and the length of the grindstone Is getting shorter.

If the length of the cylindrical surface 32 is changed in this way, for example, there is a possibility of adversely affecting the processing accuracy of the inner diameter straightness, taper, and cylindricity of the first inner diameter surface 44.
For this reason, a biaxial internal grinding device equipped with a grindstone for the first inner diameter surface 44 and a grindstone for the nozzle sheet surface 42 may be used.

  Accordingly, an object of the present invention is to keep the length of the generatrix of the cylindrical surface at a predetermined length even when the inclined surface is dressed in an internal grinding wheel having a slope and a cylindrical surface.

In order to achieve the above object, the present invention provides a first cylindrical surface portion having a rotation axis as a center line, the first cylindrical surface portion concentric with the first cylindrical surface portion, and continuous with the first cylindrical surface portion. A cylindrical surface portion having a second cylindrical surface portion having a diameter smaller than that of the cylindrical surface portion, and a slope portion having the rotation axis as a center line and continuing to one of the first cylindrical surface portion and the second cylindrical surface portion. A dressing device for dressing an internal grinding grindstone composed of: a slope part dressing means for dressing the slope part, and a cylindrical surface having an outer diameter equal to or smaller than the outer diameter of the second cylindrical surface. The cylindrical surface portion forming means for forming the second cylindrical surface portion on the formed cylindrical surface so that the length of the generatrix of the cylindrical surface portion becomes a predetermined value with respect to the dress amount of the inclined surface portion. And a second cylindrical surface portion forming means for forming Providing less device (first configuration).
In the first configuration, the second cylindrical surface portion forming means may be configured to shape the second cylindrical surface portion on one end side facing the side where the slope portion is formed (second Constitution).
In addition, the present invention provides a first cylindrical surface portion having a rotation axis as a center line and a diameter smaller than the first cylindrical surface portion, which is concentric with the first cylindrical surface portion and is continuous with the first cylindrical surface portion. A cylindrical surface portion having a second cylindrical surface portion, and a slope portion continuous with either the first cylindrical surface portion or the second cylindrical surface portion with the rotation axis as a center line. A grindstone mounting means capable of mounting an internal grinding wheel, a work holding means for holding a workpiece, a grinding means for grinding an inner surface of the held workpiece with the internal grinding wheel, and a dressing the first internal grinding wheel. A grinding apparatus characterized by comprising a dressing device having a configuration or a second configuration is provided (third configuration).
In addition, the present invention provides a first cylindrical surface portion having a rotation axis as a center line and a diameter smaller than the first cylindrical surface portion, which is concentric with the first cylindrical surface portion and is continuous with the first cylindrical surface portion. A cylindrical surface portion having a second cylindrical surface portion, and a slope portion continuous with either the first cylindrical surface portion or the second cylindrical surface portion with the rotation axis as a center line. A dressing method for dressing an internal grinding wheel, wherein a slope part dressing step for dressing the slope part and the cylindrical surface part are formed such that an outer diameter is a cylindrical surface equal to or smaller than an outer diameter of the second cylindrical surface. And a second cylindrical surface portion forming the second cylindrical surface portion on the formed cylindrical surface so that the length of the generatrix of the cylindrical surface portion becomes a predetermined value with respect to the dressing amount of the inclined surface portion. And a cylindrical surface portion forming step. Providing (fourth configuration).
Furthermore, the present invention provides a first cylindrical surface portion having a rotation axis as a center line and a diameter smaller than the first cylindrical surface portion, which is concentric with the first cylindrical surface portion and is continuous with the first cylindrical surface portion. A cylindrical surface portion having a second cylindrical surface portion, and a slope portion having the rotation axis as a center line and continuing to one of the first cylindrical surface portion and the second cylindrical surface portion. A numerical control program for dressing an internal grinding wheel, wherein the slope portion dressing function for dressing the slope portion and the cylindrical surface portion become a cylindrical surface whose outer diameter is equal to or smaller than the outer diameter of the second cylindrical surface. The second cylindrical surface portion is formed on the formed cylindrical surface so that the length of the generatrix surface portion has a predetermined value with respect to the cylindrical surface portion forming function and the dressing amount of the inclined surface portion. Numerical system that realizes the second cylindrical surface part forming function with an internal grinding machine Providing a program (fifth configuration).
In addition, the present invention provides a disk member, a first cutting edge portion fixed to the disk member, dressed on a cylindrical surface having a central axis parallel to the central axis of the disk member, and fixed to the disk member. A dresser is provided, comprising: a second cutting edge portion that dresses a slope that forms a predetermined angle with the central axis of the disk member (sixth configuration).

  According to the present invention, in the internal grinding wheel having an inclined surface and a cylindrical surface, the length of the generatrix of the cylindrical surface can be kept at a predetermined length even if the inclined surface is dressed.

(1) Outline of Embodiment FIG. 3A shows the outer shape of a grindstone according to the present embodiment.
As shown in FIG. 3A, by providing a step portion at one end of the cylindrical surface 32, the cylindrical surface 32 is divided into a first cylindrical surface 35 and a second cylindrical surface having a smaller outer shape than the first cylindrical surface 35. 36.

When dressing the slope 31, as shown in FIG. 3B, the cylindrical surface 32 including the step is dressed to form a cylindrical surface 32 a having no step.
And as shown in FIG.3 (c), the level | step-difference part is formed in the position where the length of the bus line of the 1st cylindrical surface 35a becomes L, and the 2nd cylindrical surface 36a is provided. That is, the escape dress is put on the cylindrical surface 32.

  In this way, each time the slope 31 is dressed, the first inner surface 44 (FIG. 7) is ground by forming the cylindrical surface 32 so that the length of the generatrix of the first cylindrical surface 35 is L. (That is, the length of the generatrix of the first cylindrical surface 35) can be kept at a constant value L.

(2) Details of Embodiment FIG. 1A is a plan view showing a layout of an internal grinding apparatus according to the present embodiment.
The internal grinding device 1 can control the rotation speed of the spindle, the movement path (pass) of the grindstone, the dressing amount (cutting amount) of the grindstone, the number of dressings (number of cuttings), the discharge of coolant, and the like by numerical control. It consists of NC machine tools.
For this reason, the workpiece can be automatically machined by executing the machining program, and the grindstone 8 can be automatically dressed by executing the dress program.

The internal grinding device 1 includes a work head spindle 16, a motor 23, and a grindstone spindle 12.
The work head spindle 16 includes a rotating shaft held by a bearing. A work holding part (work holding means) for detachably holding the fuel injection nozzle 2 is formed at the tip of the rotating shaft.

The workpiece holding unit is configured by a holding mechanism such as a diaphragm chuck, a collet chuck, or a power chuck, for example.
On the other hand, a pulley 20 is attached to the other end of the rotating shaft.

The motor 23 is disposed such that the rotation shaft is parallel to the rotation shaft of the work head spindle 16, and a pulley 24 is provided at the tip of the rotation shaft.
A belt 22 is hung on the pulley 24 and the pulley 20, and the rotational driving force of the motor 23 is transmitted to the work head spindle 16 via the belt 22.

Therefore, the motor 23 can be driven to rotate the fuel injection nozzle 2 mounted on the work holding portion around the center line.
In the inner surface grinding apparatus 1 of the present embodiment, the work head spindle 16 using a pulley belt is used. However, the invention is not limited to this, and a built-in structure in which a motor is directly attached to the work head spindle is used. You can also.

  The grindstone spindle 12 includes a rotating shaft and a motor for driving and rotating the rotating shaft, and the rotating shaft is disposed so as to be parallel to the rotating shaft of the work head spindle 16.

At the tip of the rotating shaft of the grindstone spindle 12, a mounting mechanism (whetstone mounting means) for mounting and holding a metal rod (sometimes called a quill) provided on the grindstone 8 is provided. The grindstone 8 can be attached to the tip of the rotating shaft.
A flow path for supplying a coolant (grinding fluid) is provided inside the metal rod, and the coolant is discharged from the vicinity of the tip of the grindstone 8 and supplied to the grinding location. .
Further, when the fuel injection port is already formed in the protrusion 45 (FIG. 7A), it is also possible to supply the grinding fluid from this injection port.

The grindstone spindle 12 can rotate at a high speed of about 150,000 revolutions per minute, and can achieve an optimum peripheral speed for the grindstone 8.
The rotational speed and direction of the grinding wheel spindle 12 can be set by a numerical control program.

  The internal grinding device 1 inserts the grindstone 8 into the fuel injection nozzle 2 while rotating the fuel injection nozzle 2 and the grindstone 8, and applies the grindstone 8 to the inner surface of the fuel injection nozzle 2. Grinding can be performed over the entire circumference (grinding means).

The grindstone 8 is configured by hardening abrasive grains with resin at the tip of a highly rigid metal rod.
In the present embodiment, as an example, the grindstone 8 is made of CBN (cubic boron nitride), but this does not limit the material of the grindstone 8 and selects a material according to the workpiece or the like. be able to.

The grindstone spindle 12 is installed on the upper surface of the table 14, and the table 14 is installed on the upper surface of the table 13.
The table 14 is installed to be movable in the x-axis direction (the slope direction of the grindstone 8), and the table 13 is installed to be movable in the z-axis direction (main axis direction).
The moving amount and moving speed of these tables are controlled by numerical control.

The grindstone spindle 12 can move in the zx plane by moving the table 14 and the table 13.
Note that an angle formed by the x-axis and the z-axis (also an angle formed by the slope of the grindstone 8 and the cylindrical surface) is α.

Thus, by making the angle formed by the x-axis and the z-axis the same as the angle formed by the slope of the grindstone 8 and the cylindrical surface, the movement of the table 14 and the like during dressing can be simplified.
For example, the slope 31 (FIG. 3A) of the grindstone 8 can be dressed by fixing the table 13 and moving the table 14 in the x-axis direction.

Note that the angle formed by the x-axis and the z-axis is not necessarily equal to the angle formed by the slope of the grindstone 8 and the cylindrical surface.
In this case, the dressing may be performed by simultaneously controlling the x-axis and the z-axis to move the grindstone spindle 12 in the slope direction.

The motor 18 is a motor for rotating the dresser 19 and is fixed in the vicinity of the work head spindle 16. The motor 18 can hold the dresser 19 in a detachable manner.
The dresser 19 is a disk-type rotary dresser configured by using a disk member as shown in FIG. 1B, and has cutting edges on the outer ring portion 25a and the slope portion 26a as will be described later.

  When dressing the grindstone 8, while rotating the motor 18 and the grindstone spindle 12, the grindstone spindle 12 is moved in the zx plane, and the grindstone 8 is brought into contact with these cutting blades formed on the surface of the dresser 19. Then, the surface of the grindstone 8 is ground and dressed by the cutting blade.

  The dressing is performed while supplying the coolant by a coolant supply device (not shown). This coolant supply device also supplies coolant even when the fuel injection nozzle 2 is ground.

  Note that dressing is an operation of removing the surface of the grindstone whose grinding ability has been reduced by dropping off the abrasive grains, clogging or clogging of the grindstone, and regenerating the state of the abrasive grains on the grindstone surface. The dressing process is also called dressing.

  Further, a forming operation for correcting the grinding wheel grinding surface and correcting the runout with respect to the rotation axis is called truing. However, since all are grinding processes for the surface of the grinding stone 8, the dress of the present embodiment also has the concept of truing. It will be described as including.

  As described above, the internal grinding device 1 constitutes a dressing device that dresses the grindstone 8 by the dresser 19 and constitutes a grinding device that grinds the fuel injection nozzle 2.

Next, the structure of the dresser 19 will be described with reference to FIG. FIG. 2A shows a sectional view of the dresser 19 in the radial direction, and FIG. 2B shows a plan view of the dresser 19.
The dresser 19 is composed of a disk member 27 made of a metal material such as iron, aluminum, or stainless steel. A through hole 28 for mounting on the spindle of the motor 18 is formed at the center of the disk member 27.

  A slope portion is provided on the outer peripheral portion of the dresser 19 so as to protrude from the outer periphery of the dresser 19. And the outer ring part cutting blades 25, 25, 25, ... are arranged on the outer ring part of the slope part, and the slope part cutting blades 26, 26, 26, ... are arranged on the slope part. It is configured.

  The outer ring portion cutting blades 25 are made of, for example, diamond grains having a rectangular parallelepiped shape, and a plurality of outer ring portion cutting blades 25 are arranged on the outer ring portion 25a of the disk member 27 so as to be concentric with the central axis. In the present embodiment, 24 outer ring cutting edges 25 are arranged at equal intervals.

Further, the outer ring portion cutting blade 25 protrudes perpendicularly to the central axis of the disk member 27, and the tip of the exposed portion dresses the cylindrical surface 32 of the grindstone 8 as will be described later.
Thus, the outer ring portion cutting blade 25 constitutes a first cutting edge portion that is fixed to the disk member 27 and dresses the cylindrical surface 32 having a central axis parallel to the central axis of the disk member 27.

  The slope portion cutting blade 26 is also made of, for example, diamond grains having a rectangular parallelepiped shape, and protrudes perpendicularly from the slope portion 26a to the slope portion 26a. In the present embodiment, 24 slope cutting edges 26 are arranged at equal intervals.

As will be described later, the tip of the exposed portion of the slope portion cutting edge 26 dresses the slope 31 of the grindstone 8.
As described above, the inclined surface cutting edge 26 is fixed to the disk member 27 and constitutes a second cutting edge portion that dresses the inclined surface 31 that forms a predetermined angle with the central axis of the disk member 27.

  In this embodiment, the grindstone 8 is dressed by the dresser 19, but this is not limited to the dresser 19 for dressing the grindstone 8, and various types of dressers can be used and will be described later. What is necessary is just to obtain the shape after a desired dress.

Next, the dress of the grindstone 8 will be described.
Fig.3 (a) is the figure which showed the external shape of the grindstone 8 which concerns on this Embodiment.
The grindstone 8 has an inclined surface 31 (inclined surface portion) centered on the rotation axis and a cylindrical surface 32 (cylindrical surface portion) that is continuous with the inclined surface 31 and has the rotational axis as the central axis.

The cylindrical surface 32 further includes a first cylindrical surface 35 (first cylindrical surface portion) continuous with the inclined surface 31 and a second cylindrical surface 36 (continuous with the first cylindrical surface 35 and having a smaller diameter than the first cylindrical surface 35. (Second cylindrical surface portion). Here, let L be the length of the bus bar of the first cylindrical surface 35.
FIG. 3A also shows the directions of the z axis and the x axis. The z-axis is the direction of the rotation axis of the grindstone 8, and the x-axis is the direction of the generatrix of the slope 31 in the horizontal plane (which forms an angle α with respect to the z-axis).

FIG. 3B is a diagram for explaining dressing of the slope 31 and the cylindrical surface 32.
In the drawing, in order to show the positional relationship between the dresser 19 and the grindstone 8, the cutting edge portion of the dresser 19 is also illustrated.

First, the dressing of the slope 31 is performed by placing the slope portion cutting edge 26 against the slope 31 and moving the grindstone 8 back and forth in the x-axis direction. A dress amount of the slope 31 in the z direction is A.
In this way, a new slope 31 a is formed by dressing the slope 31.

  The dressing of the cylindrical surface 32 is performed by putting the outer ring portion cutting blade 25 against the cylindrical surface 32 and moving the grindstone 8 back and forth in the z-axis direction. The dress amount of the cylindrical surface 32 is set to be equal to or greater than the step between the first cylindrical surface 35 and the second cylindrical surface 36, thereby forming a cylindrical surface 32 a having an outer diameter equal to or smaller than the outer diameter of the second cylindrical surface 36.

After forming the cylindrical surface 32a in this manner, the inner surface grinding apparatus 1 moves the outer ring portion cutting blade 25 to the end of the cylindrical surface 32a (the end on the side facing the inclined surface 31), as shown in FIG. And then dressing back and forth in the z direction to form the second cylindrical surface 36a.
The outer diameter of the second cylindrical surface 36a is smaller than the outer diameter of the first cylindrical surface 35a (the portion obtained by removing the second cylindrical surface 36a from the cylindrical surface 32a). In this way, the first cylindrical surface portion and the second cylindrical surface portion are re-formed.

Further, the inner surface grinding apparatus 1 is more in the −z direction than the position (shown by the dotted line in FIG. 3C) where there is a step between the first cylindrical surface 35 and the second cylindrical surface 36 before dressing. A second cylindrical surface 36 a is formed from a position shifted by A in a direction far from 31. As a result, the length of the bus bar of the first cylindrical surface 35a becomes L.
As described above, the length of the first cylindrical surface 35a, which is a portion for grinding the first inner diameter surface 44 (FIG. 7), can be maintained at a constant value L while dressing the slope 31.

  In the above description, the processing is performed in the order of formation of the inclined surface 31a, formation of the cylindrical surface 32a, and formation of the second cylindrical surface 36a. However, the processing order may be arbitrary, and finally the inclined surface 31a, the cylindrical surface 32a, the first It is only necessary to obtain two cylindrical surfaces 36a.

Next, a modification of the shape of the grindstone 8 will be described.
FIG. 4 is a view showing the shape of a grindstone 8a which is a modification of the grindstone 8. As shown in FIG.
The grindstone 8a is the same as the grindstone 8 in that the cylindrical surface 32 is constituted by the first cylindrical surface 35 and the second cylindrical surface 36 having an outer diameter smaller than that of the first cylindrical surface 35. 36 is formed on the slope 31 side.

  In the grindstone 8 a, when the slope 31 is dressed, the slope 31 moves backward in the −z direction, that is, the end portion on the side where the slope 31 is not formed, but the newly formed slope 31 interferes with the first cylindrical surface 35. If not, the length of the bus bar of the first cylindrical surface 35 is kept at a constant value L.

  As described above, the second cylindrical surface 36 may be formed on the inclined surface 31 side or may be formed on the side facing the inclined surface 31, and the grindstone 8 and the grindstone 8 a are centered on the rotation axis. A first cylindrical surface 35, and a second cylindrical surface 36 that is concentric with the first cylindrical surface 35 and that is continuous with the first cylindrical surface 35 and has a smaller diameter than the first cylindrical surface 35. The surface 32 and the inclined surface 31 having the rotation axis as a center line and continuing to one of the first cylindrical surface 35 and the second cylindrical surface 36 are included.

Next, the hardware configuration of the internal grinding device 1 will be described.
FIG. 5 is a block diagram showing an example of a hardware configuration of the inner surface grinding apparatus 1.
The internal grinding device 1 includes a CPU (Central Processing Unit) 65, a ROM (Read Only Memory) 66, a RAM (Random Access Memory) 67, an input unit 68, a display unit 69, a drive control unit 71, an input / output I / F (interface). ) 72, each of the functional units such as the storage medium driving unit 73 and the storage unit 74 is connected by a bus line 75.

The CPU 65 performs numerical control of each element constituting the inner surface grinding apparatus 1 such as the table 13, the table 14, the grindstone spindle 12, the motor 23, and the supply of coolant according to the numerical control program.
The CPU 65 also performs various types of information processing in accordance with a predetermined program such as file input / output and acceptance of numerical control program editing.

The ROM 66 is a read-only memory that stores basic programs and data for operating the internal grinding device 1.
The RAM 67 is a readable / writable memory that provides a working area for the CPU 65 to operate.

The input unit 68 is a functional unit for inputting information to the inner surface grinding apparatus 1, and includes an input device such as a keyboard and a touch panel.
The input device includes character keys and numeric keys for inputting numbers, characters, symbols, etc., function keys for designating preset functions, and the like.
By operating the input unit 68, the user can create, call, and edit a numerical control program, and set various parameters that define the operation of the inner surface grinding apparatus 1.

The display unit 69 includes a display device such as a liquid crystal display, a CRT (Cathode-Ray Tube) display, or a plasma display, and can display character information and image information.
The user can display the numerical control program on the display unit 69 and edit it, or can display a menu screen prepared in advance and use it to set various parameters.

  The drive control unit 71 is connected to a drive system such as an AC servo motor, for example, and the CPU 65 includes the table 13, the table 14, the grindstone spindle 12, the motor 23, a coolant supply device, and the like via the drive control unit 71. Can be controlled.

The input / output I / F 72 is an interface for connecting the internal grinding device 1 to an external device.
By connecting the internal grinding device 1 to an external device such as a personal computer using the input / output I / F 72, a numerical control program can be transmitted and received between the internal grinding device 1 and the external device.
For this reason, a numerical control program can be prepared externally and input to the internal grinding device 1 from the input / output I / F 72.

The storage medium drive unit 73 is a functional unit that drives the attached removable storage medium and reads and writes numerical control programs and the like.
Examples of the readable / writable storage medium include a flexible disk, a magneto-optical disk, a semiconductor storage device, and a magnetic tape.
In addition, examples of the read-only storage medium include optical disks such as CD-ROM and paper tape.

The storage unit 74 is a readable / writable storage device configured by, for example, a semiconductor memory or a hard disk.
The storage unit 74 includes a program unit 76 that stores programs and a data unit 77 that stores data.

  As shown in FIG. 5B, the program unit 76 stores an OS (Operating System) 81, a machining program 82, a dress program 83, and other various programs that can be executed by the CPU 65.

The machining program 82 and the dress program 83 are numerical control programs for machining the fuel injection nozzle 2 and dressing the grindstone 8, respectively.
A plurality of machining programs 82 and dress programs 83 can be stored, and can be managed by a registration ID such as a program number.
When processing or dressing, the target program can be called from the program unit 76 and executed by the CPU 65.

The OS 81 is a program for causing the CPU 65 to perform basic functions for operating the internal grinding device 1 such as file input / output management.
The data unit 77 stores various parameters and coordinate values for operating the internal grinding device 1, an operation history 86 of the internal grinding device 1, and the like.

  Next, a procedure for dressing the grindstone 8 will be described using the flowchart of FIG. The following processing is performed by the CPU 65 controlling each part of the internal grinding device 1 according to the dress program 83.

First, the internal grinding device 1 reads the previous dress data recorded in the operation history 86 (step 5).
The previous dress data includes coordinate values that define the positions of the slope 31 and the cylindrical surface 32 formed by the previous dress, and the internal grinding device 1 thereby allows the dresser 19 to be dressed this time. And the grindstone 8 can be grasped and dressing can be continued from the surface of the grindstone 8 dressed last time.

When the internal grinding device 1 reads the previous dress data, it drives the tables 13 and 14 to move the grindstone 8 to the dress start position near the dresser 19.
Then, the internal grinding device 1 drives the motor 18 to rotate the dresser 19 and also drives the grindstone spindle 12 to rotate the grindstone 8.

  Next, the inner surface grinding apparatus 1 acquires coordinate values that define the dress start position of the slope 31 using the previous dress data, and acquires the dress amount from the dress program 83 (step 10).

Next, the internal grinding device 1 starts supplying the coolant to the dressing location, and then continuously applies the inclined surface cutting edge 26 to the inclined surface 31 to dress the inclined surface 31 (step 15). As a result, a slope 31a (FIG. 3B) is formed.
As described above, the inner surface grinding apparatus 1 includes the slope portion dressing means for dressing the slope 31.

When the dressing of the slope 31 is completed, the inner surface grinding apparatus 1 acquires the coordinate value that defines the dress start position of the cylindrical surface 32 using the previous dress data and also acquires the dress amount from the dress program 83 (step 20). .
Next, the inner surface grinding apparatus 1 applies the sloped cutting edge 26 to the cylindrical surface 32 and dresses the cylindrical surface 32 to form the cylindrical surface 32a (FIG. 3B) (step 25).
As described above, the inner surface grinding apparatus 1 includes a cylindrical surface portion forming unit that forms the cylindrical surface 32 so that the outer diameter is a cylindrical surface equal to or smaller than the outer diameter of the second cylindrical surface 36.

  Next, the inner surface grinding apparatus 1 acquires coordinate values that define the dress start position of the second cylindrical surface 36 using the previous dress data and also acquires the dress amount from the dress program 83 (step 30).

Next, the inner surface grinding device 1 dresses the outer ring portion cutting edge 25 against the second cylindrical surface 36a to form the second cylindrical surface 36a (FIG. 3C) (step 35).
At this time, the inner surface grinding apparatus 1 determines that the length of the generatrix of the first cylindrical surface 35a becomes a predetermined value L (FIG. 3C) from the dress amount of the slope 31 (A in FIG. 3B). In addition, the formation position of the second cylindrical surface 36a is controlled.

  As described above, the inner surface grinding apparatus 1 applies the shape of the cylindrical surface 32a to the molded cylindrical surface 32a so that the length of the generatrix of the first cylindrical surface 35a becomes a predetermined value (here, L) with respect to the dress amount of the inclined surface 31. Second cylindrical surface portion forming means for forming the second cylindrical surface 36a is provided.

When the grindstone 8 is dressed as described above, the internal grinding device 1 stops the coolant supply, the motor 23, and the grindstone spindle 12, and drives the table 14 and the table 13 to move the grindstone 8 to a predetermined position.
Further, the internal grinding device 1 records the dress data of the dress performed this time in the operation history 86.

  In the present embodiment, the inclined surface 31, the cylindrical surface 32, and the second cylindrical surface 36 are formed by dressing them in this order, but the forming order may be arbitrary, for example, the inclined surface 31, the second cylindrical surface. The order of the surface 36 and the cylindrical surface 32 may be sufficient, and the order of the 2nd cylindrical surface 36, the cylindrical surface 32, and the slope 31 may be sufficient.

Further, the above procedure is a case of dressing the inclined surface 31. However, when the first inner diameter surface 44 (FIG. 7A) of the fuel injection nozzle 2 is ground, the first cylindrical surface 35 is also removed from the abrasive grains. It will be crushed and you will need to dress occasionally.
In this case, when the dress amount is smaller than the step formed by the first cylindrical surface 35 and the second cylindrical surface 36, the second cylindrical surface 36 is formed even after the first cylindrical surface 35 is dressed. Only the cylindrical surface 35 needs to be dressed.

  On the other hand, when the dress amount is equal to or greater than the step formed by the first cylindrical surface 35 and the second cylindrical surface 36, the second cylindrical member is dressed so that the outer diameter is constant over the entire cylindrical surface 32. Surface 36 is formed. Alternatively, the first cylindrical surface 35 may be formed after the second cylindrical surface 36 is formed.

As described above, the following effects can be obtained by the embodiment described above.
(1) Even if the bus bar of the first cylindrical surface is shortened by dressing the slope, the length of the bus bar of the first cylindrical surface is reduced by forming the first cylindrical surface and the second cylindrical surface again on the cylindrical surface. Can be constant. That is, the grindstone length can be kept uniform.
(2) In the case of the grindstone according to the modified example, the length of the generatrix of the first cylindrical surface can be made constant even if the inclined surface is dressed until the inclined surface interferes with the first cylindrical surface.
(3) Since the length of the generatrices of the 1st cylindrical surface which is the surface which grinds the 1st inside diameter surface is constant, high processing accuracy (inside diameter cylindricity, straightness, etc.) can be maintained.

It is a top view for demonstrating the layout of the internal grinding apparatus which concerns on this Embodiment. It is a figure for demonstrating the structure of the dresser which concerns on this Embodiment. It is a figure for demonstrating the shape and dressing method of a grindstone. It is a figure for demonstrating the shape of the grindstone concerning a modification. It is the block diagram which showed an example of the hardware structure of an internal grinding apparatus. It is a flowchart for demonstrating the procedure which dresses a grindstone. It is a figure for demonstrating the internal grinding of the fuel injection nozzle using a grindstone. It is a figure for demonstrating the dress of the grindstone by a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal grinding apparatus 2 Fuel injection nozzle 8 Grinding wheel 12 Grinding wheel spindle 13 Table 14 Table 16 Work head spindle 18 Motor 19 Dresser 20 Pulley 22 Belt 23 Motor 24 Pulley 25 Outer ring part cutting blade 26 Slope part cutting blade 31 Slope 32 Cylindrical surface 35 1 cylindrical surface 36 2nd cylindrical surface

Claims (6)

A first cylindrical surface portion having a rotation axis as a center line, and a second cylindrical surface portion that is concentric with the first cylindrical surface portion and that is continuous with the first cylindrical surface portion and has a smaller diameter than the first cylindrical surface portion. And an inner surface grinding wheel composed of a cylindrical surface portion having a center line as a center line and a slope portion continuous with one of the first cylindrical surface portion and the second cylindrical surface portion. A dressing device,
Slope part dressing means for dressing the slope part;
A cylindrical surface portion forming means for forming the cylindrical surface portion so as to be a cylindrical surface having an outer diameter equal to or smaller than the outer diameter of the second cylindrical surface;
Second cylindrical surface portion forming means for forming a second cylindrical surface portion on the formed cylindrical surface such that the length of the generatrix of the cylindrical surface portion is a predetermined value with respect to the dress amount of the slope portion;
A dressing device comprising:   The dressing device according to claim 2, wherein the second cylindrical surface portion forming means forms the second cylindrical surface portion on one end side facing the side where the slope portion is formed.   A first cylindrical surface portion having a rotation axis as a center line, and a second cylindrical surface portion that is concentric with the first cylindrical surface portion and that is continuous with the first cylindrical surface portion and has a smaller diameter than the first cylindrical surface portion. And an inner surface grinding wheel composed of a cylindrical surface portion having a rotation axis and a slope portion continuous with either the first cylindrical surface portion or the second cylindrical surface portion. 3. A grinding wheel mounting means, a workpiece holding means for holding a workpiece, a grinding means for grinding an inner surface of the held workpiece with the inner grinding wheel, and dressing the inner grinding wheel. A grinding apparatus comprising: the dressing apparatus described above. A first cylindrical surface portion having a rotation axis as a center line, and a second cylindrical surface portion that is concentric with the first cylindrical surface portion and that is continuous with the first cylindrical surface portion and has a smaller diameter than the first cylindrical surface portion. And an inner surface grinding wheel composed of a cylindrical surface portion having a center line as a center line and a slope portion continuous with one of the first cylindrical surface portion and the second cylindrical surface portion. Dressing method,
A slope dressing step for dressing the slope;
A cylindrical surface portion molding step for molding the cylindrical surface portion so that the outer diameter is a cylindrical surface equal to or smaller than the outer diameter of the second cylindrical surface;
A second cylindrical surface portion forming step for forming a second cylindrical surface portion on the formed cylindrical surface such that the length of the generatrix of the cylindrical surface portion is a predetermined value with respect to the dress amount of the slope portion;
A dress method characterized by performing. A first cylindrical surface portion having a rotation axis as a center line, and a second cylindrical surface portion that is concentric with the first cylindrical surface portion and that is continuous with the first cylindrical surface portion and has a smaller diameter than the first cylindrical surface portion. And an inner surface grinding wheel composed of a cylindrical surface portion having a center line as a center line and a slope portion continuous with one of the first cylindrical surface portion and the second cylindrical surface portion. A numerical control program for
Slope part dressing function for dressing the slope part,
A cylindrical surface portion forming function for forming the cylindrical surface portion so as to be a cylindrical surface having an outer diameter equal to or smaller than the outer diameter of the second cylindrical surface;
A second cylindrical surface portion forming function for forming a second cylindrical surface portion on the formed cylindrical surface such that the length of the generatrix of the cylindrical surface portion is a predetermined value with respect to the dress amount of the slope portion;
Is a numerical control program that realizes with an internal grinding machine. A disk member;
A first cutting edge portion which is fixed to the disk member and dresses a cylindrical surface having a central axis parallel to the central axis of the disk member;
A second cutting edge portion that is fixed to the disk member and dresses a slope that forms a predetermined angle with a central axis of the disk member;
A dresser characterized by comprising:

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