JPH02198760A - Honing head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a honing head, which is a tool used for honing to precisely polish and finish the inner surface of a hole in a workpiece.

(Prior Art) Conventional honing generally involves using a tool called a horn, which has three or more elongated grindstones attached to radial holders on the head body, on a honing machine. The grinding wheel is attached to the main shaft and is in surface contact with the inner surface of the hole of the workpiece/workpiece, giving rotational motion and reciprocating motion in the axial direction to the tool, thereby micro-cutting or polishing the inner surface of the hole.

However, conventionally, in such honing processing,
As a means of pressing the grindstone against the inner surface of the hole in the workpiece, a push rod with a tapered portion is moved in the axial direction and each holder is pushed out in the radial direction, so that all the grindstones are uniformly extended in the radial direction. structure is commonly used.

(Problem to be solved by the invention) However, in honing processing, the grinding surfaces of multiple grinding wheels are always accurately placed on the same circumferential surface centered on the head axis during processing, so that they are evenly distributed on the inner surface of the hole. Therefore, in the conventional head structure described above, the inclination and eccentricity of the tapered surfaces of the push rod and the grindstone holder that make sliding contact with each other are made equal for all the holders. In addition, each of the grinding wheels and holders must be set to the same dimensions so that all the grinding wheels have the same height, and each grinding surface must be finished completely parallel to the head axis. There was a problem in that high precision machining was required to manufacture the parts, resulting in extremely high manufacturing costs.

The present invention has been made to solve the above-mentioned conventional problems, and there is some variation in the height of the abrasive surface when not in use.
Even if the abrasive surface is inclined to some extent with respect to the head axis, all the abrasive surfaces come into contact with the inner surface of the hole with equal pressing force during machining, allowing high-precision honing to be performed without any problems.Therefore, the dimensional accuracy of each component is not affected much. The purpose of the present invention is to provide a honing head that does not require strict precision and has extremely low manufacturing costs.

(Means for Solving the Problems) In order to achieve the above object, the honing head of the present invention has a connecting portion to the rotating main shaft of a machine tool on the proximal end side, and a plurality of strips along the axial direction on the distal end side. A head body having a cylindrical whetstone mounting part with concave grooves equally spaced on the outer periphery, a whetstone holder fitted into each concave groove of the head body so as to be movable in the radial direction of the head, and a holder for these. It is equipped with a holding member that constantly presses the tool toward the center of the head, and a rod-shaped grindstone that is fixed to each grindstone holder and protrudes outward in the radial direction of the head. An operating fluid conduction path is formed to guide fluid to the inner space of the grindstone mounting portion, and the grindstone mounting portion is provided with a cylinder chamber configured with a through hole that communicates the inner space and the bottom of each groove in the radial direction. is,
A honing head in which a piston is fitted in each cylinder chamber to push up a grindstone holder in an eccentric direction by receiving fluid pressure from a working fluid.

Further, in the present invention, in the honing head described above, a through hole communicating with the internal space of the grindstone mounting part is bored in the tip surface of the head body, and an internal pressure adjustment plate can be fixed at an arbitrary rotational position on the outside of the through hole. A preferred embodiment is a configuration in which the adjustment plate is attached to the adjustment plate and is provided with a discharge hole for a working fluid that can overlap with the through hole at an eccentric position of the adjustment plate.

(Function) The honing head of the present invention connects the connecting portion of the head body to the rotating main shaft of the machine tool during honing.
Before processing, each grindstone holder with a grindstone attached is pressed against the bottom of the concave groove of the grindstone mounting part by the pressure of the holding member.
Each grindstone is in its lowest protruding state. When working fluid is pressurized into the working fluid conduit of the head body during machining, the pistons in each cylinder chamber move in response to this fluid pressure, pushing up each grinding wheel holder in an eccentric direction, and each grinding wheel The amount of protrusion increases uniformly and comes into pressure contact with the inner surface of the hole to be machined.

Since all the cylinder chambers communicate with each other through the internal space of the head body, this pressure contact force will be equal for all the grindstones if the pressure-receiving area of the piston corresponding to each grindstone holder is the same.

(Example) Hereinafter, the present invention will be explained based on illustrated embodiments.

In FIGS. 1 to 4, reference numeral 1 denotes a head body rotatably supported by a support housing 2 via a bearing 2a (FIG. 3), and a mounting member 11a to a main shaft 3a of a machine tool 3 and a manipulator. The proximal end member 11 has a holding part 11b concentrically arranged at one end and a connecting hole 11c at the other end, and the narrow diameter part 12a at one end is inserted into the connecting hole 11C and engaged. Proximal member 1 via stop pin 13
A cylindrical tip end member 12 which is connected concentrically and non-rotatably relative to the tip end member 1 and whose other end forms a large-diameter grindstone mounting portion 1a, and a bottomed cylindrical portion 14a is fitted into the tip end member 12. The sealing member 14 is fixed to the distal end member 12 via bolts 15 at the outer end flange portion 14b.

The tip side member 12 has a small diameter hole 12b opened at one end and a large diameter hole 12c located inside the grindstone mounting part 1a and opened at the other end, which are concentrically communicated with each other. The outer peripheral surface has a plurality of deep grooves 16 along the axial direction.
and shallower and narrower grooves 17 are formed alternately and evenly spaced in the circumferential direction, and each groove 16 has a bottom portion and a large diameter hole 12c.
A plurality of (three in the illustration) radial through holes 18 are bored to communicate with the two. In each of the grooves 16, a substantially rectangular bar-shaped grindstone holder 5 with a square-shaped grindstone 4 mounted and fixed on the upper surface side is fitted so as to be movable in the radial direction of the head, that is, to be movable up and down within the groove 16. In addition, a rectangular bar-shaped guide member 19 is embedded and fixed in each of the grooves 17 with its top slightly protruding from the outer peripheral surface of the distal end member 12 via pins 19a, 19a.

On the other hand, each through hole 18 constitutes a cylinder chamber, and a short cylindrical piston 6 is loaded inside the cylinder chamber. Incidentally, abrasive particles such as diamond are fixed to the top surface of the grinding wheel 4 by electrodeposition or the like to form a grinding surface 4a.

The bottomed cylindrical portion 14a of the sealing member 14 is provided with communicating holes 20 having a smaller diameter than the through holes 18 in the radial direction at positions corresponding to the through holes 18 of the distal end member 12. Hole 2
0 forms the through hole 18, that is, the air inlet/outlet to the cylinder chamber, and also serves to prevent the piston 6 from being pulled out toward the inner space 14c. Further, a circular recess 14d is formed at the center of the outer end surface of the sealing member 14, and the inner space 1 is formed at the bottom of the circular recess 14d.
A plurality of eccentric through holes +4e communicating with the through holes 4c are equally spaced on the same circumferential line, and the recess 14d is provided with a plurality of discharge holes 7a on the same circumferential line as the through holes 14e. A disc-shaped internal pressure adjusting plate 7 is fixed via a mounting plate 7b.

As shown in FIG. 5, the whetstone holding part 5 has a shallow groove 5a along the longitudinal direction on the upper surface side, and two recesses 5b with a depth slightly deeper than the groove 5a are cut out at two opposing locations on both side surfaces. A screw insertion hole 5c is formed between the recesses sb on both sides. By screwing and tightening the nut-shaped holding piece 8b disposed in the recess 5b, the grindstone 4 is placed and fitted in the groove 5a.
is clamped and fixed between the upper edges of both clamping pieces 8a and 8b. Further, spring locking grooves 5d and 5e are formed on the upper surface side of one end of the grindstone holder 5 and on the end surface of the other end, respectively. As shown in FIGS. 1 and 3, the grindstone holders 5.5 and 5.
... are annular coil springs 10a, 1 which are fitted into these locking grooves 5d, 5e and attached to the main body 1 in a headband shape.
0b, it is always elastically biased toward the bottom side of the groove 16, that is, toward the center of the head, and is prevented from coming out of the groove 16.

On the other hand, a positioning pin 2b is attached to the support housing 2 in parallel with the head body 1.
A flow path 22 leading from the tip of b to an annular flow path 21 formed at the interface between the housing 2 and the proximal end member 11 of the head body 1
Furthermore, the proximal end member 11 of the head body 1 is provided with a center hole 11d opening into the connecting hole 11C and a radial flow path lie extending from the center hole 11d to the annular flow path 21.

In the honing head having the above configuration, during honing, the shank portion 11a of the head body 1 is connected to the rotating main shaft 3a of the machine tool 3 by a manipulator that grips the gripping portion 11b, and the positioning pin 2b is connected to a general oil-supplied one-tool holder. Similarly, it is inserted into the positioning part 3b (FIG. 3) of the machine tool. This positioning portion 3b is provided with a supply port (not shown) for a working fluid. However,
When the supply of working fluid is stopped before processing, each grinding wheel holder 5
is pressed by the coil springs 10a and 10b, and its bottom surface is at the lowest level where it contacts the bottom of the recess 16, and in this position, the grindstone 4 is in a protruding state with the grinding surface 4a slightly lower than the top surface of the guide member 19. Next, the honing head is aligned with the hole in the workpiece using the top surface of the guide material 19, 19... as an index, and when a working fluid is supplied under pressure from the supply port, this fluid flows from the flow path 22 to the annular shape. Channel 21 → Channel l
The route of ie → center hole 11d → small diameter hole 12b → large diameter hole 12c → inner space 14c → communication hole 20 is repeated in order to reach the through hole 18 which is the cylinder chamber, and this fluid pressure causes each piston 6 to act as a coil spring + Oa + ob The grindstone holder 5 is pushed up by moving eccentrically against the bias of the grindstone 4.
protrudes outward from the guide material 19 and is pressed against the hole circumferential surface of the workpiece. Therefore, by applying rotational motion and axial reciprocating motion to the head body 1 in this pressing state, the required honing process is performed.

After machining is completed, by reducing the supply pressure of the working fluid to zero, each holder 5 returns to the head axis side with the piston 6 due to the elastic pressure of the coil springs 10a and 10b, and the grindstone returns to the low protrusion state before machining. becomes. Note that although air is normally used as the working fluid, oil (hydraulic type) and other fluids can also be used.

Here, in the embodiment configuration, the pressing force of each grindstone 4 against the inner surface of the hole of the workpiece is
It can be arbitrarily set before processing depending on the degree of polymerization between e and the discharge hole 7a of the internal pressure adjustment plate 7. That is, both holes 14
e,? By adjusting the flow rate of the working fluid discharged from the inner space 14c to the outside through the inner space 14c,
The fluid pressure can be adjusted to reduce the supply pressure. Of course, both holes +4e,? Honing is possible even in a state where the discharge flow rate is zero and a is made non-communicating.

In the above embodiment, the grindstone holder 5 has two pairs of clamping pieces 8a.
, ab, the grindstone is clamped and fixed by the holder, but in addition to clamping, various well-known means such as direct screw fixing, adhesion, welding, etc. can be employed as means for fixing the whetstone to the holder. Also,
In the above embodiment, a communication hole 20 having a smaller diameter than the through hole 18 is provided in the bottomed cylindrical portion 14a of the sealing member 14 in order to prevent the piston 6 from being removed. A constriction part with a smaller diameter than the cylinder chamber is provided, and the sealing member 1
4, a simple end plate without a bottomed cylindrical portion is used as the tip side member 12.
It may also be a sealing member fixed to the end face of.

Furthermore, in the present invention, a spring material or an elastic material other than the annular coil springs lOa and 10b may be used as a holding member for each grindstone holder, or a center through type in which the working fluid is introduced from a flow path along the axis of the head body 1. It is also possible to do this. Further, the number of installed grindstone holders, the number of installed pistons corresponding to each holder, and other detailed configurations can be modified in various ways other than those shown in the example, and the guide member 19 may be omitted.

(Specific Effects) According to the honing head according to the present invention, the plurality of whetstone holders are movable in the radial direction of the head in the concave grooves along the axial direction of the whetstone mounting part, and are normally pressed toward the center of the head by the holding member. A structure in which each holder is provided with a cylinder chamber in which the holder is fitted and communicated with the inner space of the mounting part, and each holder is pushed up in an eccentric direction by movement by the fluid pressure of a piston in the cylinder chamber during processing. Therefore, even if there is some variation in the height of the grinding surface when the grindstone fixed to the holder is not in use, or even if the grinding surface is tilted to some extent with respect to the head axis, all the grinding surfaces are The surface presses against the inner surface of the hole in the workpiece with a uniform pressing force, allowing highly accurate honing to be performed without any problems.

Therefore, according to the present invention, strict dimensional accuracy is not required for the grindstone, the grindstone holder, the groove in which the holder is fitted, etc.
Since each member is easier to manufacture and the overall structure of the head is simple, manufacturing costs can be significantly reduced compared to conventional honing heads of this type.

In addition, in the above-mentioned honing head, a through hole communicating with the inner space of the grindstone mounting part is bored in the tip surface of the head main body, and an internal pressure adjustment plate is attached to the outside of the through hole so that it can be fixed at any rotational position, In addition, if a configuration is adopted in which the adjustment plate is provided with a discharge hole for the working fluid that can overlap with the through hole at an eccentric position, the discharge amount of the working fluid changes depending on the degree of overlap between the through hole and the discharge hole. Since the fluid pressure in the space can be adjusted to be reduced, the pressing force of each grindstone against the inner surface of the hole of the workpiece can be set arbitrarily.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of the honing head, Fig. 2 is a front view of the tip portion of the same, and Fig. 3 is a view taken along the line ■-■ in Fig. 2. Arrow sectional view, 4th
The figure is a sectional view taken along the line ■--■ in FIG. 3, and FIG. 5 is an exploded perspective view of the grindstone holder of the grindstone. 1... Head main body, 1a... Grindstone mounting part, 3...
Machine tool, 3a... Rotating main shaft, 4... Grinding wheel, 5...
- Grindstone holder, 6... Piston, 7... Internal pressure adjustment plate, 7a... Release hole, 10a, 10b... Annular coil spring (holding member), 11e... Channel (operating fluid conduction path), 12b...large diameter hole (operating fluid conduction path)
, 12c... Large diameter hole (operating fluid conduction path), 14c...
...Inner space, 14e...Through hole, 16...Concave groove, 1
8... Through hole (cylinder chamber), 21... Annular channel (fluid conducting path for operation), 22... Channel (fluid conducting path for operating).

Claims (2)

[Claims] (1) A head equipped with a cylindrical grindstone mounting part that has a connecting part to the rotating main shaft of the machine tool on the base end side, and a cylindrical grindstone mounting part on the distal end side with a plurality of concave grooves extending along the axial direction and equally spaced on the outer periphery. A main body, a grindstone holder fitted into each groove of the head body so as to be movable in the radial direction of the head, a presser member that constantly presses these holders toward the center of the head, and fixed to each grindstone holder. The head body is provided with a rod-shaped grindstone that protrudes outward in the radial direction of the head, and a working fluid conduit passage is formed in the head body to guide working fluid supplied from the outside to the inner space of the grindstone mounting portion. The mounting part is provided with a cylinder chamber composed of a through hole that communicates the inner space and the bottom of each concave groove in the radial direction, and the grindstone holder is moved in an eccentric direction by receiving the fluid pressure of the working fluid in each cylinder chamber. A honing head fitted with a piston that pushes up. (2) A through hole communicating with the internal space of the grindstone mounting part is bored in the tip surface of the head body, and an internal pressure adjustment plate is attached to the outside of the through hole so that it can be fixed at any rotational position, and the adjustment 2. The honing head according to claim 1, further comprising a discharge hole for a working fluid that can be polymerized with the through hole at an eccentric position of the plate.