JPH11262866A - Whetstone adapter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To increase the holding force of a fitting joint between a drive-side coupling and a grindstone holder so that a grindstone can be attached and detached with one touch. SOLUTION: A non-circular columnar driving force receiving portion as viewed from above is provided at a lower end of a cylindrical joint portion extending upward from a center portion of an upper surface of a whetstone pad, and a concave portion in which a part of a ball fits is formed on an upper outer peripheral surface thereof. A driving portion fitted to the driving force transmission portion at a lower end of a cylindrical driving side coupling fitted to the cylindrical joint portion; and a driving force transmission portion located above the driving portion and provided above the driving portion. A ball fitting hole is provided in the drive-side coupling at a position facing the recess when the drive unit is fitted so that a ball projects inward by a predetermined amount, and is always downwardly provided on the outer peripheral surface of the drive-side coupling. Is slidably fitted to the holding cylinder, which is urged to hold the ball and the concave portion in a normal fitting state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
000r. p. m. Hereinafter, a peripheral speed of 1000 m / min.
The present invention relates to a grindstone adapter that enables one-touch attachment and detachment of a grindstone in an electric tool or an air tool such as a hand polisher, a disc grinder, and a disc sander used in the following.

[0002]

2. Description of the Related Art Conventionally, various one-touch type attachment / detachment devices for a drive-side coupling (input boss) connected to an output shaft of a motor (reduction gear) of a hand polisher and a grindstone holder (grindstone pad or the like) have been proposed. For example, 5-7
0860). However, a stainless steel cylindrical pin is inserted into the diametric hole at the lower end of the cylindrical joint part extending upward from the center of the upper surface of the grinding stone pad to which the diamond grinding disk is fixed with a cloth fastener (trade name: Velcro fastener) on the lower surface. The radially extending slit provided at the lower end of the drive side coupling fitted to the cylindrical joint is fitted to the cylindrical pin to transmit the rotational force to the grindstone holder. Is adopted,
If the grinding wheel pad is at least made of aluminum, the holding power of the pin cannot be secured unless it is made of aluminum. Therefore, the grinding pad becomes not only heavy but also requires complicated processing (such as NC processing) such as pin hole processing and is therefore expensive. . In addition, rattling is likely to occur in the fitting portion between the pin and the slit, and the main body of the hand polisher vibrates during the polishing operation, and the finishing accuracy may be reduced. There was also a problem that irregular wear and runout of the grindstone were likely to occur, and that the whetstone might come off when subjected to a rotational force in the opposite direction.

[0003]

SUMMARY OF THE INVENTION The present invention enhances the holding force and strength of the fitting joint between the drive-side coupling and the grindstone holder, and does not come off when a rotational force in either the forward or reverse direction is applied. It is an object of the present invention to provide an inexpensive whetstone adapter that can prevent abrasion and noise due to vibration and the like, maintain the centering function stably for a long period of time, and can attach and detach a whetstone with one touch.

[0004]

According to a first aspect of the present invention, there is provided a non-circular columnar driving force transmission to a lower end of a columnar joint extending upward from a central portion of an upper surface of a grinding wheel pad. A driving part fitted on the lower end of a cylindrical driving side coupling fitted on the cylindrical joint part with the driving force transmission part at a lower part of a cylindrical coupling part fitted on the cylindrical joint part; And the ball is fitted into the drive-side coupling at a position facing the recess when the drive unit is fitted above the drive unit and the drive force transmission unit so as to project inward by a predetermined amount. A ball insertion hole is provided, and a holding cylinder constantly urged downward is slidably fitted on the outer peripheral surface of the drive-side coupling so that the ball and the concave portion are normally held in a fitted state. It is a whetstone adapter.

According to a second aspect of the present invention, in the grinding wheel adapter according to the first aspect, at least the grinding wheel pad among the grinding wheel pad, the drive side coupling, the holding cylinder, and the ball is formed of a hard resin. It is.

According to a third aspect of the present invention, there is provided the grinding wheel adapter according to the first aspect, wherein a grinding wheel disk is integrally formed on a lower surface of the grinding wheel pad.

According to a fourth aspect of the present invention, there is provided the grinding wheel adapter according to the first aspect, wherein the grinding wheel disk has a cooling water passage at a position away from the center.

[0008]

FIG. 1 is a longitudinal sectional front view of a hand polisher 5 in a state in which a grinding wheel adapter 4 according to the present invention is mounted on an output spindle 3 protruding downward from a gear box 2 attached to a tip end of a grip body 1. A motor (not shown) incorporated in the grip body 1 is connected to a home power supply or the like via a cable 6 and is turned on / off by a switch 7, so that the tip of the motor (left end)
Is connected to a downwardly directed output spindle 3 via a reduction gear in a gear box 2. Output spindle 3
Is provided with a step portion 8, a male screw portion 9 (right-hand thread) therebelow, and a cooling water passage 10 at the center thereof. The upper end of the cooling water passage 10 is provided via a nipple with an adjusting cock 11 on a side surface of the gear box 2 and a hose 12. Connected to a water supply (not shown). The amount of cooling water can be adjusted by the adjusting cock 11, and the above structure is generally known in the related art.

The external thread 9 of the output spindle 3 is screwed into the female thread 15 of the upper half of the cylindrical drive-side coupling 14 in the center of the grindstone adapter 4 so that the step 8 forms the upper end surface of the drive-side coupling 14. Is pressed against. Reference numeral 16 denotes a cooling water passage. The lower end of the slightly thin cylindrical portion 17 in the lower half of the drive-side coupling 14 is enlarged in diameter so that the inner surface forms a substantially triangular cylindrical drive portion 18 (see FIG. 2B) when viewed from below. The top is as a rounded radius. The triangular cylindrical drive unit 18 applies a rotational force to the disc-shaped grindstone pad 13 described later.
In order to transmit to the (grinding stone holder), it is fitted to the driving force transmission part 22 (see FIG. 3B) at the lower end of the cylindrical joint part 21 extending upward from the center of the grinding stone pad 13. A concave portion 19 into which a part of the ball 23 is fitted is provided on the outer peripheral surface of the intermediate height portion of the cylindrical portion 17 at an equal interval on the same circumference. Reference numeral 24 denotes three equally-spaced cooling water passages provided on the same circumference at a position away from the center. The driving unit 18 is connected to the driving force transmission unit 22.
1, a ball insertion hole 20 is formed at a position of the cylindrical portion 17 facing the concave portion 19, and a ball 23 is provided on the inner edge of the ball insertion hole 20 on the side of the cylindrical joint portion 21. Is provided with an annular projection 20a (see FIG. 2C) so as not to protrude inward beyond a certain amount.
When a holding cylinder 28 to be described later is fitted and lowered to the position shown in FIG. 1, the inner surface of the holding cylinder 28 pushes the ball 23 inward to press the ball 23 against the concave portion 19, and at this time, the ball 23 The dimensions of the respective parts are determined so as to be slightly separated to the right of. Although an annular groove can be used instead of the concave portion 19, the use of the illustrated concave portion 19 which is adapted to each ball 23 can reduce the occurrence of play as much as possible. Reference numeral 27 denotes a cooling water passage provided on the grinding wheel disk 25 so as to communicate with the cooling water passage 24.

The disk-shaped grinding wheel pad 13 has a cylindrical portion 17 at the center.
A cylindrical joint portion 21 having a diameter that is slidably fitted on the inner surface of the motor, and a driving force transmission portion 22 at the lower end thereof that meshes with the driving portion 18 as described above. As a material of the grinding wheel pad 13 in FIG. 1, a relatively hard resin, for example, polycarbonate, polypropylene, nylon, or the like is suitable.
A diamond grindstone disk 25 is integrally fixed to the lower surface. The grindstone disk 25 can be adhered to the lower surface of the grindstone pad 13 or fixed by a hook-and-loop fastener. However, the grindstone pad 13 is molded in a state where the disc 25 manufactured in advance is set in a mold (not shown). If the two are integrated simultaneously with this molding, the number of manufacturing steps is reduced, and the cost is reduced. Of course, it is also possible to integrally form the grindstone pad 13 with the grindstone disk 25 and omit the illustrated grindstone pad 13. Reference numeral 26 denotes a surface to be polished such as a tombstone or a marble floor or a wall. The driving force receiving portion 22 can be formed in a polygonal shape such as a quadrangle, a non-circular shape such as an elliptical shape or an oval shape when viewed from above.

The presser cylinder 28 is slidably and firmly fitted on the outer peripheral surface of the cylindrical portion 17, has a flange 29 near the upper end of the outer peripheral surface which pulls upward when the pad is released, and has a cylindrical portion 30 at the lower end for preventing balls from falling off. The inner surface between the flange 29 and the cylindrical portion 30 is provided with a tapered guide surface 31 that expands downward.

A spring stop collar 34 is fitted into a small diameter portion at the upper end of the outer periphery of the coupling 14, and a ring groove 35 thereabove.
The collar 34 is prevented from coming out of the upper part by the snap ring 36 (E-ring) fitted to the. Reference numeral 37 denotes a coupling spring which is contracted between the collar 34 and the flange 29. The illustrated spring 37 is a compression coil spring, whereby the presser cylinder 28 is constantly urged downward so that the lower surface 38 of the main body presses against the upper surface 39 of the drive unit 18 and the inner surface of the presser cylinder 28 makes the ball 23 By pushing inward in the direction, the ball 23 is fitted into the concave portion 19 to prevent the grinding stone pad 13 from dropping downward. The coupling 14, the ball 23, the holding cylinder 28, and the collar 34 can be made of SUS, brass, or the like, but can also be made of the same resin as the pad 13, for example, polycarbonate, polypropylene, nylon, or the like. And cost reductions are possible. Instead of the spring 37 (made of spring steel), a coil spring made of resin or a thin cylinder made of a rubber-like elastic body, a bellows whose section is shown wavy, a disc spring made of metal or resin and arranged alternately, or the like is used. Can be employed, in which case ball 2
The distance between the presser cylinder 28 and the collar 34 (in the embodiment shown in FIG.
1) is kept low, so that the amount of downward projection of the grinding wheel adapter 4 is reduced, which enables weight reduction and cost reduction, and improves operability. The lower end of the pad 13 may be thinned to a thickness of 0.5 to 1.5 mm so that the concave curved surface of the stone can be polished, or the material may be made of a soft resin such as a urethane resin to increase flexibility. It is valid.

In order to polish the surface 26 to be polished, an operator grips the grip body 1 with, for example, the right hand, turns on the switch 7 and turns the motor. Then, the spindle 3 rotates rightward when viewed from above, and this rotational force is transmitted from the drive unit 18 of the drive-side coupling 14 to the pad 13 via the drive force transmission unit 22, and the grinding wheel disc integrated with the pad 13 25 is rotated to perform polishing. Meanwhile, hose 12
From the cooling water passages 10, 16, 24, 27
Is supplied between the grindstone disk 25 and the surface to be polished 26 to cool the two and prevent scattering of dust. Generally, the grinding is changed from a coarse grinding wheel to a finer grinding wheel, and the amount of cooling water is generally gradually reduced. When replacing the whetstone with a finer whetstone, first, the switch 7 is turned off, the whetstone adapter 4 is stopped, the cock 11 is closed or opened, and the gear box 2 is used as a fulcrum and the flange 2 is
9 is lifted upward (in the direction of arrow X1) by the release amount L1 (to the positions of 28a and 31a) against the elasticity of the spring 37 to release the ball 23, and the pad 13 is pulled down in this state. Then, the ball 23 is pushed by the concave portion 19 and moves radially outward, retreats to the same plane as the inner surface of the cylindrical portion 17 or outside thereof, and the pad 13 can be removed. Next, in a state where the presser cylinder 28 is pulled up by L1 (in a state where it is pulled up to the positions of 28a and 31a), the pad 13 with a slightly fine disk is pushed up to the state of FIG. 1 to release the presser cylinder 28. The presser cylinder 28 is lowered to the state shown in FIG. 1 by the resilience of the spring 37, and the ball 23 is fitted into the concave portion 19. Therefore, even if the switch 7 is turned on and the polishing operation is restarted, the grinding wheel disk 25 comes off. Is reliably prevented.

[0014]

According to the first aspect of the present invention, the driving section 18 is engaged with the driving force transmission section 22 and the ball 23 is held in the holding cylinder 28.
As a result, the transmission of the driving force and the pad 1
3, the holding force (strength) of the mating joint between the drive-side coupling 14 and the grinding wheel pad 13 increases, and even when used in severe conditions for a long time, No matter which rotational force is applied, there is no danger that the power transmission portion and the retaining portion will be worn or rattled.
Can be reliably prevented from coming off or rattling. Therefore, wear and noise due to torsional vibration and the like can be reliably prevented. Moreover, the attachment and detachment of the whetstone pad 13 is possible with almost one touch,
Handling becomes easy. Since the structure is simple, there is an advantage that it can be manufactured at low cost. In addition, resinification is facilitated in structure.

According to the second aspect of the present invention, at least the grinding pad 13 can be formed of a hard resin, so that the weight is reduced and there is no place to be damaged, so that the durability is improved. It is very easy to manufacture and therefore inexpensive. There is an advantage that operability can be improved by reducing the weight.

According to the third aspect of the present invention, as shown in FIG. 1, the operation of fixing the grinding wheel disk 25 to the grinding wheel pad 13 is simplified, which is effective for cost reduction, and it is easy to secure concentricity between the two. Finishing accuracy is also improved.

According to the fourth aspect, the water discharged from the cooling water passage 27 at the eccentric position at the time of driving scatters radially along the lower surface of the grindstone disk 25 by centrifugal force.
For example, when polishing the substantially vertical lower edge of a stone material such as a gutter turned upside down (even if the lower half of the grinding wheel disk 25 is exposed downward), cooling water scattered on the polishing surface is supplied. Polishing efficiency is improved. That is, when there is only one cooling water passage at the center of the grinding wheel disk 25, in the case of the above example, the cooling water is not supplied to the polishing surface, but such a problem can be reliably prevented. . Water often reaches the corners when polishing the floor.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view when the present invention is applied to a hand polisher.

2 (A) is a vertical sectional front view of the drive-side coupling unit alone in FIG. 1, FIG. 2 (B) is a bottom view taken along the line IIB-IIB in FIG. 2A,
FIG. 2C is an enlarged view of a portion C of FIG. 2A.

FIG. 3A is a front view showing a single pad of FIG. 1;
FIG. 3B is a plan view of FIG.
It is the C section enlarged view of (A).

[Explanation of symbols]

 4 Grinding Stone Adapter 13 Grinding Stone Pad (Grinding Stone Holder) 14 Drive Side Coupling 18 Drive Unit 19 Concave 20 Ball Fitting Hole 22 Drive Power Transfer Part 23 Ball 25 Grinding Stone Disc 27 Cooling Water Passage 28 Presser Tube 37 Coupling Spring

Claims (4)

[Claims] 1. A concave portion in which a non-circular columnar driving force receiving portion as viewed from above is provided at a lower end of a columnar joint portion extending upward from a center portion of an upper surface of a grinding stone pad, and a part of a ball fits into an upper outer peripheral surface thereof. And a drive portion fitted to the drive power transmission portion at the lower end of the cylindrical drive side coupling fitted to the cylindrical joint portion, and the drive power transmission portion located above the drive portion and being provided above the drive portion. A ball insertion hole is provided in the drive-side coupling at a position opposed to the concave portion when the drive portion is fitted to the portion, so that a ball is inserted so as to project a predetermined amount inward, and the ball is always provided on the outer peripheral surface of the drive-side coupling. A whetstone adapter characterized in that a holding cylinder urged downward is slidably fitted to hold a ball and a recess in a normal fitted state. 2. The whetstone adapter according to claim 1, wherein at least the whetstone pad among the whetstone pad, the drive side coupling, the holding cylinder, and the ball is formed of a hard resin. 3. The whetstone adapter according to claim 1, wherein a whetstone disk is integrally formed on a lower surface of the whetstone pad. 4. The whetstone adapter according to claim 1, wherein the whetstone disk has a cooling water passage at a position away from the center.