JPH07164306A - Honing device - Google Patents

Abstract

PURPOSE:To provide the honing device the grinding wheel expanding mechanism of which is simplified. CONSTITUTION:The slide sections 5b of a plurality of grinding wheel mounting pieces 5 are slidably provided for the tip end section of rotating shaft 4 rotatably supported by a cylindrical main body 2 so as to be freely expanded/ contracted, a grinding wheel 6 is mounted at the tip end sections of the grinding wheel mounting pieces 5, each expanding weight 7 is concurrently mounted on a base end section, and a return spring 8 is wound around the circumference of the intermediate sections of the grinding wheel mounting pieces 5. Besides, the grinding wheel mounting pieces may be made slidable along a guide cylinder in place of the slide sections 5b, so that the aforesaid mounting pieces are expanded/contracted by means of fluid led into a fluid chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honing device which is designed to simplify a grindstone expanding mechanism.

[0002]

2. Description of the Related Art Conventionally, as a device for finish grinding the inner surface of a bore, a honing device such as, for example, Japanese Utility Model Laid-Open No. 1-155161 is known. And with this device,
The upper end of the grindstone mounting piece with the grindstone attached to the lower end is pivotally attached to the rotary shaft with a fulcrum pin so that the grindstone expands outward by the centrifugal force when the rotary shaft rotates. There is.

[0003]

However, the above-mentioned device has a problem that it is difficult to apply it especially when the hole diameter is small. In addition, since the whetstone mounting piece is guided only by the fulcrum pin, the whetstone easily falls and there is a problem in terms of processing accuracy.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a rotary shaft rotatably supported by a tubular body and a sliding mechanism formed at the tip of the rotary shaft in the radial direction. A plurality of grindstone mounting pieces that can slide and expand and contract, and a grindstone mounted on the tip of this grindstone mounting piece,
A honing device provided with an expansion means attached to the base end of the grindstone attachment piece was constructed. Then, the grindstone mounting piece is provided with a diameter reducing means for moving it inward in the radial direction.

Further, as the expansion means, an expansion weight utilizing centrifugal force when the rotating shaft rotates is adopted. Alternatively, the expanding means is constituted by a fluid pressure applied through a fluid chamber formed at the base end of the grindstone mounting piece.

[0006]

[Operation] The sliding mechanism formed at the tip of the rotary shaft allows the grindstone mounting piece to slide in the radial direction to allow expansion / contraction, so that the expansion / contraction mechanism is simply configured and is applicable regardless of the size of the hole diameter. Is easy. Also, by using a sliding mechanism,
The whetstone mounting piece does not fall, and the whetstone position is stable.
Further, by providing the diameter reducing means for moving the inner side in the radial direction, the device can be easily inserted into the processed hole. Here, an expansion weight can be used at low cost as an expansion means, and by using fluid pressure, the pressing force of the grindstone can be easily set, and the pressing force can be kept constant regardless of the number of revolutions. You can

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the honing device of the present invention will be described with reference to the accompanying drawings. 1 is a cross-sectional view of a first configuration example of the present device, FIG. 2 is a front view of the device as viewed from the direction A in FIG. 1, FIG. 3 is a cross-sectional view taken along line BB of FIG. 1, and FIG. 4 is C of FIG. -C
It is a line sectional view.

As shown in FIG. 1, the honing device of the present invention has a cylindrical main body 2 attached to the front portion of a housing 1.
A rotary shaft 4 rotatably supported by the tubular main body 2 via a bearing 3; and a plurality of slide shafts slidable along a dovetail groove m (FIG. 4) provided on the front surface of the rotary shaft 4. The grindstone mounting piece 5 is provided, and the grindstone 6 is mounted on the outer surface side of the tip portion of the grindstone mounting piece 5.

In the tubular shape of the tubular body 2, a portion where the bearing 3 is disposed is a circular portion 2a, and the front thereof is an elliptical elliptical portion 2b as shown in FIG.

A large-diameter portion 4a having a diameter larger than that of the bearing 3 is provided in front of the rotary shaft 4.
The diameter of a is made slightly smaller than the diameter of the elliptical portion 2b on the short circle side, and the dovetail groove m is formed in the large diameter portion 4a.
It is provided on the front surface of a, and in the embodiment, six pieces are provided at equal intervals on the circumference in the radial direction from the center of the rotating shaft 4.

Further, a slide portion 5b which engages with the dovetail groove m is provided at the base end portion of the grindstone mounting piece 5, as shown in FIG.
As shown in FIG. 5, there is the slide portion 5b, which is engaged with the groove m and is slidable.

A wide portion 5a (FIG. 1) that is wide in the radial direction is formed on the base end side of the grindstone mounting piece 5, and the slide portion 5b is formed on the end surface of the wide portion 5a and the wide portion. An expansion weight 7 is provided as an expansion means on the side opposite to 5a.

That is, the grindstone mounting piece 5 spreads outward in the radial direction by rotation of the rotary shaft 4,
The expansion weight 7 is provided to increase the centrifugal force in order to apply a predetermined pressing force to the ground surface.

A return spring 8 as a diameter-reducing means that surrounds the periphery of each grindstone mounting piece 5 and urges it inward is wound around the base end side of these grindstone mounting pieces 5. The biasing force of the spring 8 is weak enough to lose the centrifugal force of the grindstone mounting piece 5 accompanying the rotation of the rotary shaft 4.

The operation of the honing device having the above configuration will be described.

As shown in FIG. 1, in order to finish the inner surface of the elliptical bore b of the workpiece W that has been previously drilled, the tip of the grindstone mounting piece 5 having a reduced diameter is inserted into the elliptical bore b.

Then, when the rotary shaft 4 is rotated, the grindstone mounting piece 5 slides in the groove m by centrifugal force and spreads outward. Then, the grindstone 6 of the grindstone mounting piece 5 contacts the inner surface of the elliptical bore b and is pressed toward the inner surface by the extension weight 7.

Then, as shown in FIG. 3, each of the whetstone mounting pieces 5 has a radius of the rotary shaft 4 so as to expand outward in the elliptical portion and immerse inward in the short circular portion, following the inner surface shape of the elliptical bore b. Change the position while sliding in the direction, and grind with the grindstone 6 while moving the stroke. Further, at the time of this sliding, since the sliding portion 5a is wide, the posture is stable, and there is no problem of falling.

When the grinding is completed, the rotation of the rotary shaft 4 is stopped and the return spring 8 reduces the diameter of the grindstone mounting piece 5.

Next, a second structural example will be described with reference to FIGS. 5 is a cross-sectional view of the second configuration example of the present device, FIG. 6 is a front view from the view D of FIG. 5, FIG. 7 is an enlarged view of a main part of FIG. 6, and FIG. 8 is an EE of FIG. It is a line cross-sectional view, and the same reference numerals are given to the same portions and the like as the above.

In this apparatus, a large diameter portion 4a of the rotary shaft 4 is provided with a hexagonal column-shaped protrusion 4b at the center end thereof.
Six guide cylinders 10 extending radially from b are fixed at equal intervals along the circumference.

A slide hole 5c formed in the wide portion 5a of each grindstone mounting piece 5 is slidably inserted through these guide cylinders 10 through an O-ring 11 (FIG. 7). A fluid chamber 12 as shown in FIG. 7 is formed at the deepest portion of the hole 5c.

Then, in the fluid chamber 12, the guide cylinder 1
A hydraulic passage 14 centering on the rotating shaft 4 is communicated through a cylinder hole 13 of 0, and by guiding a hydraulic pressure of a predetermined pressure into the fluid chamber 12, the grindstone mounting piece 5 is directed outward along the guide cylinder 10. It is made to slide.

By the way, as shown in FIG. 8, the end face of the wide portion 5a of each grindstone mounting piece 5 is in sliding contact with the front surface of the large diameter portion 4a of the rotary shaft 4, and in front of the cylindrical main body 2. A guide member 15 that restricts movement is provided.

In this apparatus, when the grindstone mounting piece 5 is inserted into the elliptical bore b, a hydraulic pressure of a predetermined pressure is introduced from the hydraulic passage 14 and the grindstone mounting piece 5 is slid outward to move the grindstone 6 into the bore b. It is brought into contact with the inner surface, and the rotary shaft 4 is rotated and the stroke is moved while machining.

This hydraulic pressure is stronger than the inward urging force of the return spring 8, and the radial inward reaction received from the inner wall of the elliptical bore b when the grindstone 6 moves from the oval to the oval. It is weaker than power.

Therefore, in this device, there is an advantage that the predetermined pressure can be maintained without being influenced by the rotational speed by expanding the hydraulic pressure. Needless to say, the bore shape is not limited to an ellipse, and may be a perfect circle or another non-perfect circle.

[0028]

As described above, in the honing device of the present invention, the sliding mechanism is formed at the tip of the rotary shaft, and the whetstone mounting piece is slid in the radial direction by this sliding mechanism. Can be simplified and can be constructed at low cost. Further, it can be easily applied even if the processed hole diameter is small. Also,
By adopting a sliding mechanism, expansion and contraction will be smooth, and the grindstone mounting piece will have a stable posture and will not fall over easily. Further, if an expansion weight is adopted as the expansion means, the device can be constructed inexpensively and simply, and by utilizing the fluid pressure, the pressing force of the grindstone can be kept constant regardless of the rotation speed of the rotary shaft. Produce an effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a first configuration example of this device.

FIG. 2 is a front view of the device viewed from the direction A in FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a cross-sectional view of a second configuration example of this device.

6 is a front view from the view D in FIG.

7 is an enlarged view of a main part of FIG.

FIG. 8 is a sectional view taken along line EE of FIG.

[Explanation of symbols]

 2 tubular body 4 rotating shaft 5 grindstone mounting piece 6 grindstone 7 expansion weight 8 return spring 10 guide tube 12 fluid chamber 14 hydraulic passage

Claims (4)

[Claims] 1. A rotary shaft that is rotatably supported by a tubular body, and a plurality of grindstone attachment pieces that are slidable in the radial direction by a sliding mechanism formed at the tip end of the rotary shaft and are expandable and contractible. With a grindstone attached to the tip of this grindstone mounting piece,
A honing device comprising: an expansion means attached to the base end of the grindstone attachment piece. 2. The honing device according to claim 1, wherein the grindstone mounting piece is provided with a diameter reducing means for moving it inward in the radial direction. 3. The honing device according to claim 1, wherein the expansion means is an expansion weight that utilizes centrifugal force when the rotary shaft rotates. 4. The honing device according to claim 1, wherein the expanding means is a fluid pressure applied through a fluid chamber formed at a base end portion of the grindstone mounting piece.