JP3735487B2 - Honing method - Google Patents

Description

【００４１】
一方、図４中、領域Ａの下端位置を回転角度θの関数ｙ＝ｈ（θ）で表した場合、このｈ（θ）は次の（２）式で表される。
【００４２】
【数２】

【００４３】
これら曲線ｙ＝ｇ（θ）および曲線ｙ＝ｈ（θ）に囲まれた領域Ａと、直線ｙ＝τ（Ｔ≦τ≦Ｅ）とが交わる部分の長さをＢ（τ）とすると、このＢ（τ）の値はτの値に応じて変化する。そこで、Ｔ≦τ≦Ｅの範囲内におけるＢ（τ）の最大値Ｂｍａｘと最小値Ｂｍｉｎを求め、これら最大値Ｂｍａｘと最小値Ｂｍｉｎとの差が最小値または最小に近い値となるようにメインストローク領域とサブストローク領域との割合を決定する。この場合、孔部２２の研削表面積をｙ方向においてほぼ均一化させ、円筒度が良好な孔部２２を得ることが可能な位置スケジュールを構成することができる。
【００４４】
このように、本実施の形態に係るホーニング加工方法においては、孔部２２の一端部においてホーニングヘッド１２の十分なオーバーラン寸法を確保することができない場合においても、オーバーラン寸法の不足分を補うように構成された所定の位置スケジュールに基づいてホーニングヘッド１２を進退駆動することによって、真円度が高く、しかも、円筒度が良好な孔部２２を得ることができる。
【００４５】
この場合、前記位置スケジュールは、略正弦曲線状の曲線ｆ１で示されるメインストローク領域と、同じく略正弦曲線状の曲線ｆ２で示されるサブストローク領域とによって構成されている。従って、位置スケジュールの組立を容易に行うことができる。
【００４６】
【発明の効果】
本発明に係るホーニング加工方法によれば、孔部の両端部におけるオーバーラン寸法の差に応じてホーニングヘッドの進退駆動スケジュールを変化させることによって、真円度が高く、しかも、円筒度が良好な孔部を得ることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態に係るホーニング加工装置の構成を概略的に示す図面である。
【図２】図１のホーニング加工装置を構成するホーニングヘッドとワークの孔部との位置関係を示す断面図である。
【図３】図１のホーニングヘッドを進退駆動させるべき位置スケジュールを示す図面である。
【図４】図３の位置スケジュールに従って進退駆動されたホーニングヘッドによって研削される孔部内面を示す展開図である。
【図５】図３の位置スケジュールに従って進退駆動されたホーニングヘッドによって研削される孔部内面の表面積の分布図である。
【図６】従来技術に係るホーニング加工方法において進退駆動されたホーニングヘッドによって研削される孔部内面を示す展開図である。
【図７】従来技術に係るホーニング加工方法において進退駆動されたホーニングヘッドによって研削される孔部内面の表面積の分布図である。
【図８】従来技術に係るホーニング加工方法による加工対象であるシリンダブロックを示す断面図である。
【図９】従来技術に係るホーニング加工方法による加工対象であるシリンダブロックにホーニング加工が施された後の状態を示す断面図である。
【符号の説明】
１０…加工装置 １２…ホーニングヘッド
１６…砥石 ２０…ワーク
２２…孔部 ２６…回転駆動機構
２８…進退駆動機構 ４０…コントローラ
４２…回転駆動用ドライバ ４４…進退駆動用ドライバ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a honing method, and more particularly, to a honing method that can improve grinding accuracy.
[0002]
[Prior art]
As a processing method for grinding the inner surface of a hole formed in a cylindrical shape such as a cylinder, a honing method is used. This honing method is a processing method for grinding the inner surface of the hole portion by rotating and advancing and retracting a honing head configured by mounting a grindstone on the outer peripheral portion of the horn in the hole portion.
[0003]
When honing is performed on a hole having both ends opened, the honing head is overrun by a predetermined dimension at both ends of the hole. This is for the purpose of uniformizing the amount ground by the grindstone in the axial direction of the hole and forming the hole in a columnar shape with a desired diameter.
[0004]
By the way, when one end of the hole is closed or when another member is provided in the vicinity of one end of the hole, the overrun dimension of the honing head is sufficiently secured at this one end. Can not do it.
[0005]
FIG. 6 shows a developed view of the inner surface of the hole 1. In FIG. 6, symbols T and E indicate the upper end position and the lower end position of the hole 1, respectively. Curves 3a and 3b show the displacement of the upper end position and the lower end position of one grindstone constituting the honing head, respectively. That is, in the hole portion 1 of FIG. 6, the overrun dimension N (the dimension between the lower end position E of the hole portion 1 and the lower peak position E ′ of the lower end position of the honing head) is the upper end portion. Overrun dimension M (a desired overrun dimension, which is a dimension between the upper end position T of the hole 1 and the upper peak position T ′ of the upper end position of the honing head).
[0006]
In FIG. 6, the hatched area indicates the trajectory of one grindstone that moves while the honing head rotates once. That is, this area | region has shown the surface area of the hole 1 inner surface which one grindstone grinds.
[0007]
Further, FIG. 7 shows the sum (horizontal axis) of the distance L along the circumferential direction where one grindstone is in contact with each position (vertical axis) in the axial direction of the hole 1 during one rotation of the honing head. The distribution in the direction is shown. That is, in FIG. 7, the hatched area indicates the surface area of the inner surface of the hole 1 to be ground by one grindstone. The surface area of the inner surface of the hole 1 that is ground by all the grindstones of the honing head is also shown in the same distribution diagram as FIG.
[0008]
As shown in FIG. 6, when the overrun dimension N of the honing head at the lower end of the hole 1 is smaller than the overrun dimension M at the upper end of the hole 1, as shown in FIG. The grinding surface area of the inner surface of the hole 1 in the vicinity of the lower end position E is greatly reduced as compared with the grinding surface area in the vicinity of the upper end position T of the hole 1.
[0009]
A processing method for solving such a problem is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-31664. This processing method is configured to be able to adjust the expansion force in the outward direction along the radial direction of the grindstone provided on the honing head. For this reason, in the above processing method, even when the overrun dimension at one end of the hole cannot be sufficiently ensured, by increasing the expansion force of the grindstone near the one end, the inner peripheral surface of the hole is increased. It is possible to make the grinding amount uniform.
[0010]
[Problems to be solved by the invention]
However, in the above-described processing method, when the rigidity of the wall surface changes along the circumferential direction of the hole, the roundness of the cross-sectional shape of the processed hole may be reduced. There is.
[0011]
For example, as shown in FIG. 8, a hole 7 to be processed is a cylinder 7 formed in the cylinder block 5, and a hollow portion 9 constituting a water jacket is formed around the cylinder 7 in the cylinder block 5. In such a case, on the inner wall of the cylinder 7, a portion v having a low rigidity (a portion close to the cavity 9) and a portion u having a high rigidity (a portion not close to the cavity 9) are generated.
[0012]
As shown in FIG. 9, when honing is performed on such a cylinder 7 while applying an expansion force to the grindstone, the grinding amount of the portion u having a high rigidity on the inner wall of the cylinder 7 is reduced in the portion v having a low rigidity. The amount of grinding becomes larger than the grinding amount, resulting in a disadvantage that it becomes impossible to obtain a cylinder 7 with high roundness.
[0013]
The present invention has been made to solve the above disadvantages, and an object of the present invention is to provide a honing method capable of obtaining a hole portion having high roundness and good cylindricity. .
[0014]
[Means for Solving the Problems]
In the honing method according to the present invention, a honing head configured by mounting a grindstone on the outer peripheral portion of a horn is rotated and advanced in a hole formed in a columnar shape, and the honing head is formed at one end and the other end of the hole. When the overrun dimension of the honing head is different, the honing head advance / retreat drive schedule according to the difference in the overrun dimension of the honing head at the one end and the other end is the In the honing method for grinding the inner surface of the hole by inserting a schedule to compensate for the overrun dimension difference of the honing head,
The advance / retreat drive schedule includes a main stroke area for moving the honing head back and forth within a stroke range including an overrun dimension at both ends of the hole,
Of the one end or the other end of the hole, on the side where the overrun dimension is short, it is inserted into the main stroke region in order to compensate for the difference in the overrun dimension of the honing head at the one end and the other end. A sub-stroke region for moving the honing head back and forth ,
The honing method according to claim 1, wherein the advance / retreat driving schedule is determined by performing the following first to eleventh steps.
(1) the trajectory of the first upper end of the contact area of the grinding wheel of the sub-stroke interpolation Nyutoki: a first step of obtaining a curve y = g (theta) (2) contacting the lower end of the grinding wheel of the first sub-stroke interpolation Nyutoki Trajectory of region: second step (3) for obtaining curve y = h (θ) Third step (4) for obtaining region A surrounded by these curves obtained in the first step and the second step A fourth line segment B (τ) that intersects the region A obtained in the third step and a straight line y = τ (T ≦ τ ≦ E) obtained by changing τ in the range of T ≦ τ ≦ E. Step (5) Fifth step (6) for obtaining the maximum value Bmax and the minimum value Bmin of B (τ) when the first substroke is inserted from B (τ) within the range of T ≦ τ ≦ E. ratio of the sub-stroke region which is inserted into the main stroke region and the main stroke region said initial sub-stroke insert Request curve y = g (θ): the trajectory of the contact area of the upper end of the sixth step (7) grindstone during the next sub-stroke insert to insert a sub-stroke region next in different other ratio of the proportion of Seventh step (8) Eighth step (9) for obtaining the locus of the contact area at the lower end of the grindstone when the next substroke is inserted: curve y = h (θ) The seventh step and the eighth step Ninth step (10) for obtaining a region A surrounded by these curves obtained in step (10) From B (τ) within the range of T ≦ τ ≦ E, the maximum of B (τ) at the time of inserting the next substroke A tenth step (11) for obtaining the value Bmax and the minimum value Bmin. The main stroke region and the main stroke region are inserted so that the difference between the maximum value Bmax and the minimum value Bmin becomes a minimum value or a value close to the minimum. percentage of the sub-stroke area that In this case eleventh step of determining,
T indicates the upper end position of the hole,
· E is shows the lower end position of the hole,
“Ratio” indicates the ratio between the number of times of the main stroke area and the number of times of the sub-stroke area.
[0016]
By doing in this way, a hole with high roundness and good cylindricity can be obtained.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The honing method according to the present invention will be described in detail below with reference to the accompanying drawings by giving preferred embodiments in relation to an apparatus for performing the honing method.
[0018]
FIG. 1 shows a schematic configuration of a honing apparatus (also simply referred to as a processing apparatus) 10 according to the present embodiment.
[0019]
The processing apparatus 10 includes a honing head 12. The honing head 12 includes a cylindrical horn 14, and a plurality of planar rectangular grindstones 16 provided on the outer peripheral surface of the horn 14 in parallel with the axial direction. It is composed of In this case, the diameter of the honing head 12 including the grindstone 16 is set according to the diameter of a hole 22 (for example, a cylinder) formed in the workpiece 20 such as a cylinder block which is a material to be processed by the processing apparatus 10. Yes.
[0020]
A rotary drive mechanism 26 and an advance / retreat drive mechanism 28 are coupled to the honing head 12 via a rotation shaft 24 fixed coaxially.
[0021]
The rotation drive mechanism 26 is configured by a motor, a speed reduction mechanism, and the like (not shown), and the honing head 12 is rotationally driven as the motor rotates.
[0022]
On the other hand, the advancing / retreating drive mechanism 28 is constituted by a hydraulic cylinder (not shown) or the like, and the honing head 12 is driven to advance / retreat with the advance / retreat operation of the hydraulic cylinder. The advance / retreat drive mechanism 28 may be configured using an air cylinder, an electric actuator, or the like.
[0023]
Further, the processing apparatus 10 includes a controller 40, a rotation drive driver 42, and a forward / backward drive driver 44.
[0024]
The controller 40 supplies a rotational speed signal Sa for instructing the rotational speed of the motor constituting the rotational drive mechanism 26 to the rotational drive driver 42. The rotation drive driver 42 supplies a drive current Ia based on the rotation speed signal Sa to the rotation drive mechanism 26. Along with the supply of the driving current Ia, the motor of the rotation driving mechanism 26 is driven to rotate.
[0025]
Further, the controller 40 supplies an instruction signal Sb for instructing the advance / retreat operation of the hydraulic cylinder constituting the advance / retreat drive mechanism 28 to the advance / retreat drive driver 44. The advance / retreat drive driver 44 supplies the advance / retreat drive mechanism 28 with the hydraulic pressure Pb based on the instruction signal Sb. As the pressure oil is supplied, the hydraulic cylinder of the advance / retreat drive mechanism 28 is advanced / retreated.
[0026]
As shown in FIG. 2, the overrun dimension M of the honing head 12 at the upper end portion of the hole 22 is set to a desired value (a value at which the grinding amount is substantially uniform along the axial direction). On the other hand, since a member 46 (for example, a cylinder head) is disposed in the vicinity of the lower end portion of the hole portion 22, the overrun dimension N of the honing head 12 at the lower end portion is smaller than a desired value.
[0027]
That is, the honing head 12 has a lower end position E of the hole 22 from a position T ′ where the position y along the axial direction of the hole 22 is away from the upper end position T of the hole 22 by the overrun dimension M. Is driven forward / backward within the range of the stroke S to the position E ′ which is separated by an overrun dimension N from the bottom. The center position of the hole 22 in the axial direction is indicated by O, and the center position of the honing head 12 in the axial direction is indicated by O ′.
[0028]
The honing head 12 is driven forward / backward based on a position schedule (time t-position y schedule, also referred to as an advance / retreat drive schedule) shown in FIG.
[0029]
Specifically, when an instruction to advance / retreat the honing head 12 based on the position schedule, for example, between the peaks, is supplied from the controller 40 to the advance / retreat driver 44 as the instruction signal Sb, the advance / retreat drive driver 44 supplies hydraulic pressure Pb to the advance / retreat drive mechanism 28 to drive the advance / retreat drive mechanism 28 (actually a hydraulic cylinder (not shown)) based on the position schedule. And with this supply of pressure oil, the honing head 12 is driven forward and backward based on the position schedule.
[0030]
This position schedule includes a main stroke area for moving the honing head 12 in the entire range within the stroke S, and a substroke area for moving the honing head 12 in the area near the lower end of the hole 22. It is constituted by. That is, the sub-stroke region is provided to compensate for the shortage of the overrun dimension N at the lower end portion of the hole 22 (difference from the overrun dimension M).
[0031]
In FIG. 3, the curve f1 in the main stroke area and the curve f2 in the substroke area represent the center position O ′ of the honing head 12 to be controlled by the controller 40 at each time t. In this case, the curve f1 and the curve f2 are sine curves or curves obtained by connecting straight lines with straight lines (also referred to as substantially sine curves).
[0032]
The sub stroke area is inserted at the peak position on the positive side (the lower end side of the hole 22) in the main stroke area. In this embodiment, the sub-stroke area is inserted at a rate of one period every three cycles of the main stroke area, but the position schedule may be configured at other ratios. A method of determining the ratio between the main stroke area and the sub stroke area will be described later.
[0033]
When the honing head 12 is driven forward and backward based on the position schedule of FIG. 3, the trajectory of one grindstone 16 that moves while the honing head 12 makes one rotation is shown in FIG. FIG. 4 shows a developed view of the inner surface of the hole 22. In FIG. 4, symbols T and E indicate the upper end position and the lower end position of the hole 22, respectively. Curves f3 (θ) and f4 (θ) indicate displacements of the upper end position and the lower end position of the grindstone 16 with respect to the rotation angle θ of the honing head 12, respectively.
[0034]
As described above, in the hole portion 22 in FIG. 4, the overrun dimension N at the lower end portion (between the lower end position E of the hole portion 22 and the lower peak position E ′ of the lower end position of the honing head 12). Dimension) is an overrun dimension M at the upper end (a desired overrun dimension, a dimension between the upper end position T of the hole 22 and the upper peak position T ′ of the upper end position of the honing head 12). small.
[0035]
In FIG. 4, a hatched area A indicates the surface area of the inner surface of the hole 22 that is ground by one grindstone 16 of the honing head 12.
[0036]
FIG. 5 shows the total sum (horizontal axis) of the distance L along the circumferential direction in which one grindstone 16 is in contact with the honing head 12 during one rotation at each position (vertical axis) in the axial direction of the hole 22. Is shown as a distribution in the axial direction. That is, the hatched area in FIG. 5 indicates the surface area of the inner surface of the hole 22 that is grinded by one grindstone 16. The surface area of the inner surface of the hole 22 that is ground by all the grindstones 16 of the honing head 12 is also shown in the same distribution diagram as FIG.
[0037]
As shown in FIG. 5, in the present embodiment, the grinding surface area near the lower end position E of the hole 22 and the grinding surface area near the upper end position T of the hole 22 are substantially the same. That is, the cylindricity of the hole 22 after processing becomes better than in the case of the honing method according to the prior art (indicated by a two-dot chain line in FIG. 5).
[0038]
Next, an example of a method for determining the ratio between the main stroke area and the sub-stroke area in the position schedule will be described with reference to FIG.
[0039]
In FIG. 4, the upper end position of the hatched area (area where the inner surface of the hole 22 and the grindstone 16 are in contact) A is the position along the circumferential direction of the inner surface of the hole 22 (the rotation angle θ of the honing head 12). ), Y (g) is expressed by the following equation (1).
[0040]
[Expression 1]

[0041]
On the other hand, in FIG. 4, when the lower end position of the region A is represented by a function y = h (θ) of the rotation angle θ, this h (θ) is represented by the following equation (2).
[0042]
[Expression 2]

[0043]
If the length of the portion where the region A surrounded by the curve y = g (θ) and the curve y = h (θ) and the straight line y = τ (T ≦ τ ≦ E) intersect is B (τ), The value of B (τ) changes according to the value of τ. Therefore, the maximum value Bmax and the minimum value Bmin of B (τ) within the range of T ≦ τ ≦ E are obtained, and the main value is set so that the difference between the maximum value Bmax and the minimum value Bmin becomes a minimum value or a value close to the minimum. Determine the ratio of stroke area to sub-stroke area. In this case, it is possible to configure a position schedule that makes it possible to obtain the hole 22 having a good cylindricity by making the ground surface area of the hole 22 substantially uniform in the y direction.
[0044]
As described above, in the honing method according to the present embodiment, even when a sufficient overrun dimension of the honing head 12 cannot be ensured at one end of the hole 22, the shortage of the overrun dimension is compensated. By driving the honing head 12 forward and backward based on a predetermined position schedule configured as described above, it is possible to obtain the hole 22 having high roundness and good cylindricity.
[0045]
In this case, the position schedule is constituted by a main stroke area indicated by a substantially sinusoidal curve f1 and a substroke area indicated by a substantially sinusoidal curve f2. Therefore, it is possible to easily assemble the position schedule.
[0046]
【The invention's effect】
According to the honing method according to the present invention, the roundness is high and the cylindricity is good by changing the advance / retreat driving schedule of the honing head according to the difference in overrun dimensions at both ends of the hole. A hole can be obtained.
[Brief description of the drawings]
FIG. 1 is a drawing schematically showing a configuration of a honing apparatus according to an embodiment of the present invention.
2 is a cross-sectional view showing a positional relationship between a honing head constituting the honing apparatus of FIG. 1 and a hole portion of a workpiece.
FIG. 3 is a diagram showing a position schedule for driving the honing head of FIG. 1 to move forward and backward.
4 is a development view showing an inner surface of a hole to be ground by a honing head that is advanced and retracted according to the position schedule of FIG. 3;
FIG. 5 is a distribution diagram of the surface area of the inner surface of the hole ground by the honing head driven forward and backward according to the position schedule of FIG. 3;
FIG. 6 is a development view showing an inner surface of a hole to be ground by a honing head that is driven back and forth in a honing method according to a conventional technique.
FIG. 7 is a distribution diagram of a surface area of an inner surface of a hole to be ground by a honing head that is driven back and forth in a honing method according to a conventional technique.
FIG. 8 is a cross-sectional view showing a cylinder block to be processed by the honing method according to the prior art.
FIG. 9 is a cross-sectional view showing a state after a honing process is performed on a cylinder block to be processed by the honing process method according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Processing apparatus 12 ... Honing head 16 ... Grinding wheel 20 ... Work 22 ... Hole part 26 ... Rotation drive mechanism 28 ... Advance / retreat drive mechanism 40 ... Controller 42 ... Driver for rotation drive 44 ... Driver for advance / retreat drive

Claims (1)

A honing head constructed by mounting a grindstone on the outer peripheral portion of the horn is rotated and advanced in a hole formed in a cylindrical shape, and the overrun dimensions of the honing head at one end and the other end of the hole are determined. If the difference is different, the difference between the overrun dimensions of the honing head at the one end and the other end is determined according to the difference between the overrun dimensions of the honing head at the one end and the other end. In the honing method for grinding the inner surface of the hole by inserting a supplementary schedule,
The advance / retreat drive schedule includes a main stroke area for moving the honing head back and forth within a stroke range including an overrun dimension at both ends of the hole,
Of the one end or the other end of the hole, on the side where the overrun dimension is short, it is inserted into the main stroke region in order to compensate for the difference in the overrun dimension of the honing head at the one end and the other end. A sub-stroke region for moving the honing head back and forth ,
The honing method according to claim 1, wherein the advance / retreat driving schedule is determined by performing the following first to eleventh steps.
(1) the trajectory of the first upper end of the contact area of the grinding wheel of the sub-stroke interpolation Nyutoki: a first step of obtaining a curve y = g (theta) (2) contacting the lower end of the grinding wheel of the first sub-stroke interpolation Nyutoki Trajectory of region: second step (3) for obtaining curve y = h (θ) Third step (4) for obtaining region A surrounded by these curves obtained in the first step and the second step A fourth line segment B (τ) that intersects the region A obtained in the third step and a straight line y = τ (T ≦ τ ≦ E) obtained by changing τ in the range of T ≦ τ ≦ E. step (5) from said B in the range T ≦ τ ≦ E (τ) , the first fifth step of finding a maximum value Bmax and minimum value Bmin of the sub-stroke interpolation Nyutoki of B (tau) (6 ) ratio of the main stroke region and sub-stroke region which is inserted into the main stroke region the first sub-stroke insert Request curve y = g (θ): the trajectory of the contact area of the upper end of the sixth step (7) grindstone during the next sub-stroke insert to insert a sub-stroke region next in different other ratio of the proportion of Seventh step (8) Eighth step (9) for obtaining the locus of the contact area at the lower end of the grindstone when the next substroke is inserted: curve y = h (θ) The seventh step and the eighth step Ninth step (10) for obtaining a region A surrounded by these curves obtained in step (10) From B (τ) within the range of T ≦ τ ≦ E, the maximum of B (τ) at the time of inserting the next substroke A tenth step (11) for obtaining the value Bmax and the minimum value Bmin. The main stroke region and the main stroke region are inserted so that the difference between the maximum value Bmax and the minimum value Bmin becomes a minimum value or a value close to the minimum. percentage of the sub-stroke area that In this case eleventh step of determining,
T indicates the upper end position of the hole,
· E is shows the lower end position of the hole,
“Ratio” indicates the ratio between the number of times of the main stroke area and the number of times of the sub-stroke area.

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