JP2555585B2 - Honing head for honing processing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a honing head for honing, and particularly to honing suitable for honing blind holes while maintaining good straightness of holes. This is related to the improvement of the honing head for a car.

[Conventional technology]

Conventionally, a honing head for honing the inner peripheral surface of a blind hole provided in a work is mounted on the head main body that is reciprocally movable along the axial direction, and is radiated from the axial center. It has a plurality of shoes provided, grindstones fixed to the outer circumferences of the shoes, and a taper cone arranged inside the head body.

In order to perform honing processing with the honing head having such a configuration, first, the head body is moved in the axial direction and inserted into the blind hole, and the head body is rotated about the axis while reciprocating in the axis direction. give. Then, the taper cone is moved in the axial direction to press the shoe toward the outer peripheral side to press the grindstone against the inner peripheral surface of the blind hole, and the inner peripheral surface is cut by the grindstone.

During the honing operation as described above, it is difficult to transmit the pressing force of the shoe to both ends of the grindstone in the axial direction,
The pressing force of both ends of the grindstone against the inner peripheral surface of the blind hole tends to be smaller than the pressing force of the central part in the axial direction of the grindstone against the inner peripheral surface of the blind hole, and a sufficient cutting function is provided at the both end parts. May not be obtained. Therefore, in order to maintain good straightness of the inner peripheral surface of the blind hole in this type of honing, it is common to have an excess of about 1/3 to 1/4 with respect to the axial length of the grindstone. Travel (15mm
It is desirable that the inner peripheral surface is cut by the central portion in the axial direction of the grindstone as much as possible.

[Problems to be solved by the invention]

However, in the conventional honing head for honing processing, an appropriate amount of overtravel can be secured on the open end side of the blind hole, but the movement of the head body is restricted on the deep end surface side of the blind hole, so it is extremely small. Only over travel (about 2 to 3 mm) could be secured. As a result, there is a possibility that the inner peripheral surface of the blind hole may have insufficient cutting on the inner peripheral surface side, and the straightness of the inner peripheral surface of the blind hole may be reduced.

Therefore, if the length of the grindstone in the axial direction is set to be short in response to extremely small overtravel, the grindstone can be pressed against the inner circumferential surface with a substantially uniform pressure over the entire length direction, thereby solving the above problem. . However, because the axial length is short, the positioning accuracy of the grindstone in the axial direction is low, and when overtravel is applied to the open end side of the blind hole, the grindstone easily tilts in the radial direction, and Is not practical because it causes another problem that straightness decreases.

This invention is to solve the above problems, and when honing the inner peripheral surface of the blind hole, the straightness of the inner peripheral surface is good even when only a small overtravel can be secured on the inner end side surface of the blind hole. It is an object of the present invention to provide a honing head for honing that can be maintained at

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention is a honing head for honing for honing a blind hole while maintaining good straightness of the hole. A head body capable of reciprocating along the axial direction while rotating in a vertical direction; a taper cone disposed inside the head body and slidable along the axial direction of the head body; A plurality of shoes, which are fitted in groove portions formed along the axial direction of the main body and radially from the axis, respectively, and whose outer diameter can be expanded and contracted as the taper cone slides, On the basis of the tip of the head body, the outer circumference of the plurality of shoes is provided with long grindstones and short grindstones alternately fixed in the circumferential direction, and the length of the long grindstone in the axial direction is , The short It is set longer than the length of the grindstone in the axial direction, and the end of the long grindstone on the tip side of the head body, and the end of the short grindstone on the tip side of the head body is the axis. It is characterized in that they are arranged at substantially the same position in the direction.

[Action]

Explaining the operation of the present invention according to the above configuration, the head main body is reciprocally moved in the axial direction while rotating about the axial center in the blind hole, and the taper cone is slid in the axial direction to move the plurality of shoes. By expanding the outer diameter and pressing the long grindstone and short grindstone against the inner peripheral surface of the blind hole,
The inner peripheral surface of the blind hole is cut by the long grindstone and the short grindstone.

Due to the reciprocating motion of the head body, overtravel occurs on the deep end face side of the blind hole due to the long grindstone and the short grindstone. The ratio of this overtravel to the axial length of the short grindstone is greater than the ratio to the axial length of the long grindstone, so the axial end of the short grindstone is pressed against the inner peripheral surface. The force is greater than the pressing force of the end of the long grindstone in the axial direction of the inner peripheral surface, and the short grindstone can compensate for the insufficient cutting of the inner peripheral surface on the far end face side due to the long grindstone.

On the other hand, on the open end side of the blind hole, if the head body reciprocates with a stroke that gives overtravel only to the long grindstone and does not give overtravel to the short grindstone, the open end side of the inner peripheral surface The appropriate cutting is performed by the central portion of the long grindstone in the axial direction, and the inclination of the short grindstone in the radial direction is suppressed.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a schematic configuration of a honing head 1 for honing according to the present invention together with a work W to be honed, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. [Fig. 3] is a graph showing a locus of reciprocating rotation of a grindstone by a moving stroke of the grindstone with respect to a rotation angle.

The honing head 1 for honing includes a head body 2, a taper cone 4, a long shoe 5, a short shoe 6, a long grindstone 7 and a short grindstone 8. The head body 2 is connected to the tip of the drive shaft 22 and is capable of reciprocating along the direction of the axis A while rotating about the axis A.

The taper cone 4 has a structure in which shell-shaped pieces 42 and 44 are connected by a shaft 46, and is arranged inside the head body 2. When the shaft 46 is pushed by the shaft 24 inserted through the drive shaft 22, the tapered cone 4 is slidable inside the head body 2 along the axis A direction.

The long shoe 5 and the short shoe 6 are fitted in groove portions 26 formed along the axial direction A of the head main body 2 and having six radial lines extending from the axial center A. As shown in FIG. 2, the long shoes 5 and the short shoes 6 are alternately arranged in the groove portion 26 in the circumferential direction. As shown in FIG. 1, the length of the long shoe 5 in the axis A direction is set longer than the length of the short shoe 6 in the axis A direction.

The inner peripheral surface 52 of the long shoe 5 is in contact with the tapered surfaces 422 and 442 of the pieces 42 and 44 of the tapered cone 4. The inner peripheral surface 62 of the short shoe 6 is in contact with the tapered surface 422 of the piece 42 of the tapered cone 4. As a result, as the tapered cone 4 slides up and down, the long shoe 5 and the short shoe 6 reciprocate in the radial direction, and the outer diameter of the long shoe 5 and the short shoe 6 expand and contract.

A long grindstone 7 is fixed to the outer periphery of the long shoe 5,
A short grindstone 8 is fixed to the outer circumference of the short shoe 6.
Then, as shown in FIG. 1, the length of the long grindstone 7 in the axis A direction is set longer than the length of the short grindstone 8 in the axis A direction, and the end of the long grindstone 7, that is, The end 71 of the blind hole 70 on the rear end face 12 side and the end of the short grindstone 8, that is, the end 72 of the blind hole 70 on the rear end face 12 side are arranged at substantially the same position in the axis A direction. . The ends 71, 72
Is fixed with reference to the front end surface 28 on the back end surface 12 side of the head body 2.

The operation of the honing head 1 will be described below.
The honing head 1 is inserted from the open end 11 of the blind hole 70 of the work W, and the head main body 2 is given a predetermined rotational reciprocating motion.

The taper cone 4 provided inside the head body 2
The long shoe 5 and the short shoe 6 are expanded in the radial direction by sliding in the direction of the axis A. This allows
The long grindstone 7 and the short grindstone 8 are pressed to the outer peripheral side to be pressed against the inner peripheral surface 73 of the blind hole 70, and as shown in FIG. 3, the rear end surface 12 side has an arc shape and the open end 11 side has a rectangular shape. Honing is performed by cutting the inner peripheral surface 73 while repeating the reciprocating pattern of the shape.

In this embodiment, the length of the long grindstone 7 in the direction of the axis A is
The head is set to be longer than the length of the short grindstone 8 in the axis A direction, and the end 71 of the long grindstone 7 and the end 72 of the short grindstone 8 are arranged at substantially the same position in the axis A direction. During the reciprocating motion of the main body 2, overtravel is given to the long grindstone 7 and the short grindstone 8 on the inner end face 12 side of the blind hole 70,
The overtravel on the open end 11 side of the blind hole 70 is given only to the long grindstone 7 and not to the short grindstone 8.

Here, since the movement stroke of the head body 2 is restricted on the rear end face 12 side of the blind hole 70, the overtravel OTL given on the rear end face 12 side is given on the open end 11 side as shown in FIG. Less than overtravel OTU.

As described above, the ratio of the overtravel on the inner end surface 12 side of the inner peripheral surface 73 of the blind hole 70 to the length of the short grindstone 8 in the axial center A direction is larger than the length of the long grindstone 7 in the axial center A direction. Since the ratio is larger than the ratio, the pressing force of the end portion 72 of the short grindstone 8 in the axial center A direction against the inner peripheral surface 73 is equal to the inner peripheral surface 73.
It is larger than the pressing force of the end portion 71 of the long grindstone 7 in the axial center A direction, and the short grindstone 8 can compensate for the insufficient cutting of the inner peripheral surface 73 on the rear end face 12 side by the long grindstone 7.

Further, on the open end 11 side of the blind hole 70, the reciprocating motion of the head main body 2 is performed by a stroke in which only the long grindstone 7 is overtraveled and the short grindstone 8 is not overtraveled. At the open end 11 side of the peripheral surface 73, the central portion of the long grindstone 7 in the axial center A direction is pressed with an appropriate pressure to cut the area, and the inclination of the short grindstone 8 in the radial direction is suppressed. It is possible to prevent swelling of the cutting surface caused by the short grindstone 8.

Therefore, when honing the blind hole 70, the straightness of the inner peripheral surface 73 of the blind hole 70 is maintained good by the above two actions even if only a small overtravel can be set on the back end surface 12 side of the blind hole 70. To be done.

The specific embodiment of the present invention has been described above, but the present invention is not limited to this, and various other modes that can be implemented by those skilled in the art are conceivable within the scope of the claims.

For example, in the above-described embodiment, the groove portion is formed in the head body.
Although the strips are formed, the number of strips may be 4 or 8 instead of 6. In addition, the taper cone has two pieces in series,
It is not limited to three, but three or more may be arranged in series.

〔The invention's effect〕

As described above, the honing head for honing according to the present invention has a length in the axial direction of the long grindstone,
It is set longer than the axial length of the short grindstone, and
Since the end of the long grindstone and the end of the short grindstone are arranged at almost the same position in the axial direction, the overtravel on the inner end surface side of the blind hole is the length in the axial direction of the short grindstone. The ratio to the axial length of the long grindstone is greater than the ratio to the axial length of the long grindstone, and the pressing force of the axial end of the short grindstone against the inner peripheral surface is the axial center of the long grindstone against the inner peripheral surface. It is larger than the pressing force of the end portion in the direction, and the short grinding wheel can compensate for the insufficient cutting of the inner peripheral surface on the rear end face side due to the long grinding stone.

On the other hand, on the open end side of the blind hole, the axis of the long grindstone is moved by reciprocating the head body with a stroke that gives overtravel only to the long grindstone and does not give overtravel to the short grindstone. The central part of the direction is pressed against the open end side of the inner peripheral surface of the blind hole with an appropriate pressure to cut the area, and the radial inclination of the short grindstone is suppressed, and the wrinkle of the cutting surface by the short grindstone is suppressed. It can be prevented. Therefore, when honing the blind hole, the straightness of the inner peripheral surface of the blind hole can be favorably maintained by the above two actions even if only a small overtravel can be set on the back end surface side of the blind hole. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a honing head for honing according to the present invention together with a work to be honed, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a grindstone. 3 is a graph showing the locus of the reciprocating rotary motion of the above with the moving stroke of the grindstone with respect to the rotation angle. 1 …… Honing head for honing processing 2 …… Head body 4 …… Taper cone 5 …… Shoe (long shoe) 6 …… Shoe (short shoe) 7 …… Long grindstone 8 …… Short grindstone 12 …… Deep end surface 22 …… Drive shaft 26 …… Groove 70 …… Blank hole 71,72 …… End 73 …… Inner peripheral surface A …… Shaft center

Claims (1)

(57) [Claims] 1. A honing head for honing for honing a blind hole while maintaining good straightness of the hole, the honing head being connected to a tip of a drive shaft and rotating around an axis. A head main body that is reciprocally movable along the axial direction, a taper cone that is disposed inside the head main body, and is slidable along the axial direction of the head main body, and an axial direction of the head main body. A plurality of shoes that are fitted along grooves that are formed radially along the axis and that are formed radially from the axis, and the outer diameter of which can be expanded and contracted as the taper cone slides, and the tip of the head body. On the basis of the above, on the outer periphery of the plurality of shoes, a long grindstone and a short grindstone that are alternately fixed in the circumferential direction are provided, and the length of the long grindstone in the axial direction is the short grindstone. Length in the axial direction Is set longer, and the end of the long grindstone on the tip side of the head body and the end of the short grindstone on the tip side of the head body are arranged at substantially the same position in the axial direction. The honing head for honing processing, which is characterized by