JP2000141217A - Eccentricity adjusting device of working tool having eccentric mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breaking of rotational balance of a polishing part in accordance with change of eccentricity by optionally changing a distance between a driving shaft and an eccentric shaft of a working tool having an eccentric mechanism including a case where the distance is set 0. SOLUTION: A sander (polisher) 10 transmits torque of a driving shaft 4 of a motor 1 to a rotating member 12 by an eccentric shaft 15. A rotary disc 11 is fixed on the drive shaft 4 of the motor 1 eccentric disk 13 to rotate around the rotating shaft is installed at a position separated from the rotating shaft of the rotary disc 11 by a specified distance free to revolve, and the eccentric shaft 15 is provided at a position separated from a revolving center of the eccentric disc 13 by a specified distance. When the eccentric disc 13 is revolved, an eccentric distance between the driving shaft 4 and the eccentric shaft 15 changed. In case of adjusting the eccentric distance, the eccentric disc 13 is fixed at a specified revolving position by a fixing means B1. It is favourable that a balance weight to interlock with the eccentric disc 13 by drawing a specified archwise locus is provided at the time of revolving the eccentric disc 13 on the sander 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an eccentric distance adjusting device for a tool having an eccentric mechanism such as a sander, a polisher and a saw.

[0002]

2. Description of the Related Art FIGS. 29 and 30 show an example of the structure of a conventional portable rotary polishing tool (hereinafter simply referred to as a polishing tool). In this polishing tool 200, a motor 203 is incorporated into a body 201 with a handle 202 to form a main body portion V, and a polishing portion W is fitted on a drive shaft 203a. As shown in FIG. 30, the polishing section W fixes the turntable 204 to the drive shaft 203a, and rotatably assembles the eccentric shaft 206 of the polishing pad 205 at an eccentric position at a predetermined distance from the rotation center on the front surface thereof. I have. On the front surface of the polishing pad 205, an abrasive 207 such as various types of polishing cloth, paper, and buff is detachably attached. Reference numeral 208 in FIG. 29 denotes a balance weight for balancing the rotation of the polishing section W.

[0003]

As described above, a polishing tool of the type in which the polishing pad 205 is mounted at an eccentric position of the drive shaft 203a and is rotatable by itself is known in the art as a "double action sander". Or called "Random Action Thunder". Also, a numerical value representing the length twice as long as the eccentric distance in mm units is called "orbit diamond", and many commercial products set this value to a constant value of about 5.

When it is desired to change the polishing characteristics of the polishing tool 200 in accordance with the properties of the object to be polished, the purpose of polishing, the degree of progress of the polishing operation, etc., replace the abrasive with a different type of polishing material, or rotate the motor 203. The number was increasing or decreasing. And
If you want to change the `` orbit diamond '' that greatly affects the polishing characteristics as needed, there is no other way than to prepare multiple types of polishing tools with different values for the `` orbit diamond '' beforehand. Was.

[0005]

However, the replacement of the abrasive requires a considerable amount of time and work, and it is necessary to store a plurality of types of abrasive at all times. In addition, the desired number of abrasives is not always readily available.
Also, it is extremely unreasonable to prepare a plurality of polishing tools having different values of "orbit diamond" in terms of purchase cost and storage location. Furthermore, the method of changing the number of rotations of the motor has its own limit in the variable range and the effect of the change.

[0006] However, if a mechanism for changing the "orbit diamond" can be added to the polishing tool, the polishing characteristics can be more effectively improved by an extremely simple operation without troublesome replacement of the polishing material. It can be changed.

An object of the present invention is to reduce the eccentric distance between the drive shaft and the eccentric shaft of a tool having such an eccentric mechanism.
An eccentric mechanism that can be changed arbitrarily, including setting to zero, and has a balance weight interlocking mechanism to prevent the rotation balance of the polishing part from being destroyed due to a change in the eccentric distance. An object of the present invention is to provide a device for adjusting the eccentric distance of a tool having:

[0008]

An apparatus for adjusting the eccentric distance of a tool having an eccentric mechanism according to the present invention for solving the above-mentioned problems is provided by a rotary member on a driven side or a reciprocating member for rotating a driving shaft of a driving motor by an eccentric shaft. A rotating disk which is provided on a work tool having an eccentric mechanism for transmitting to a member, the rotating disk being rotated by a driving force of a driving shaft of the driving motor, and a rotating disk being rotated by a predetermined distance from the rotating shaft of the rotating disk. An eccentric disk that is freely provided, an eccentric shaft that is provided in an axial direction at a position that is separated from the center of rotation of the eccentric disk by a predetermined distance, and the drive shaft is fixed by fixing the eccentric disk at a predetermined rotation position. And a fixing means for adjusting an eccentric distance from the eccentric shaft. Further, a balance weight is provided at a position away from the eccentric board by a predetermined distance so as to draw a predetermined arc-shaped trajectory in association with the rotation of the eccentric board.

Preferably, the arc-shaped trajectory is provided according to the following procedures A to D. A. The positions of the respective centers of gravity of the rotating disk, the eccentric disk, the eccentric shaft, the fixing means, and other independent members that rotate integrally with the drive shaft are determined. B. The center of gravity of the independent member is shifted to the eccentric shaft side by a plane including the rotation axis of the drive shaft and excluding the respective centers of gravity of the independent member (excluding those located on the rotation axis of the drive shaft). It is divided into a center of gravity group and a center of gravity group opposite to the eccentric axis (hereinafter, referred to as a non-eccentric shaft side center of gravity group). C. The respective combined centroids of the eccentric shaft side center of gravity group and the non-eccentric shaft side center of gravity group are obtained. D. When the eccentric disk rotates, the following relationship is established between the combined center of gravity of the eccentric shaft side center of gravity group and the combined center of gravity of the non-eccentric shaft side center of gravity group: W1 · L1 = W2 · L2, where W1: the eccentric shaft Weight on the combined center of gravity of the side center of gravity group L1: Distance between the combined center of gravity of the eccentric shaft side center of gravity group and the rotation axis of the drive shaft W2: Weight on the combined center of gravity of the non-eccentric shaft side center of gravity group L2: The non-eccentricity The arc-shaped trajectory of the balance weight is determined so as to satisfy the distance between the combined center of gravity of the group of shaft-side centers of gravity and the rotation axis of the drive shaft.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment is shown in FIGS. First
In the embodiment, the eccentric distance adjusting device of the present invention is applied to an air motor type double action sander (polisher). As shown in FIG. 1 and FIG.
Comprises a main body 101 and a polishing section 102. In the main body 101, an air motor 1 as a rotary drive source is built in a body 3 provided with an intake pipe 2a and an exhaust pipe 2b (see FIG. 2). 4 is a drive shaft of the motor 1, 5 is an air switch, 7 is a cover, and 8 is a stop ring.

As shown in FIG. 2, the turntable 11 is fixed to the polishing section 102 on a mounting shaft 11 a connected to the drive shaft 4. An eccentric shaft 15 is rotatably mounted in the axial direction of the turntable 11 via a bearing 16. Eccentric shaft 15
A disc-shaped polishing pad 12 is rotatably mounted on the tip of the polishing pad 12. A polishing material 12a such as a polishing cloth, paper, or a buff is detachably mounted on the front surface of the polishing pad 12. When the motor 1 operates, the center of the abrasive 12a rotates while drawing a predetermined circular locus, and cuts the surface to be processed.
In addition, the rotation center a of the rotating disk 11 (the center of the drive shaft 4) and
An “orbit diagram” is twice as long as the distance between the eccentric shaft 15 and the center c (eccentric distance) (see FIGS. 6 to 8).

The polishing section 102 has an eccentric distance for arbitrarily changing the polishing characteristics of the polishing tool 10 by changing the eccentric distance (“orbit diamond”) between the drive shaft 4 and the eccentric shaft 15. An adjusting device A1 is provided.

As shown in FIG. 2, the eccentric distance adjusting device A1
, An eccentric disk 13 is provided on the axial end surface of the rotary disk 11. A circular guide concave portion 14 is formed on an end surface of the rotating disk 11, and a disk-shaped eccentric disk 13 is rotatably inserted into the guide concave portion 14. When the rotating disk 11 rotates, the eccentric disk 13 rotates around the central axis of the rotating disk 11. An eccentric shaft 15 is fixed at a position away from the center of rotation of the eccentric disk 13 by a predetermined distance. The eccentric distance between the drive shaft 4 and the eccentric shaft 15 changes as the eccentric disk 13 rotates.

A fixing means B1 is provided inside the rotary disk 11 so that the rotational position of the eccentric disk 13 can be adjusted. The fixing means B1 has a worm wheel 17 and a worm 18, as shown in FIGS. A worm wheel 17 is mounted concentrically on the back of the eccentric plate 13. The worm 18 meshing with the worm wheel 17 is assembled inside the turntable 11. Then, as shown in FIG. 2, one shaft end of the worm 18 is exposed to the outside of the turntable 11, and a hexagonal hole (rotation) into which a wrench (not shown) for rotating the worm 18 is inserted into this end surface. ) 18a.

When the worm 18 is rotated, as shown in FIG. 3, the eccentric disk 13 rotates while sliding on the inner surface of the guide recess 14, and the eccentric shaft 15 moves on a predetermined circular locus. As a result, the eccentric distance between the drive shaft 4 and the eccentric shaft 15 changes. That is, the eccentric distance is adjusted by setting the position of the worm 18 at a predetermined position.

The eccentric distance adjusting device A1 has an "eccentric distance".
The display means is provided so that the user of the polishing tool 10 can confirm the change of the polishing tool 10. That is, as shown in FIG. 4, on the upper surface of each of the rotating disk 11 and the eccentric disk 13, when the eccentric disk 13 is rotated, the value of “eccentric distance”, and therefore, the value of “orbit diamond” is changed. Corresponding numerical scales and indices 19 indicating these scales are engraved. Since the upper surface of the rotating disk 11 is covered with the polishing pad 12,
This display means may be provided on the outer surface of the cover body 7 or the like.
When the scale indicates 0 (zero), the drive shaft 4 and the eccentric shaft 15
Is 0 (zero), and the axes of the two coincide. On the other hand, when the scale indicates 6, the distance between the drive shaft 4 and the eccentric shaft 15 becomes maximum. Further, when the eccentric plate 13 is further rotated beyond the position of the scale 6, the eccentric distance gradually decreases and returns to the position of 0 (zero).

Here, as a method of changing the distance between the drive shaft 4 and the eccentric shaft 15, a method of sliding any one of the shafts on a straight line connecting the axis centers of the drive shaft 4 and the eccentric shaft 15 is also considered. Can be However, in the present invention, the reason why the eccentric shaft is provided on the disk-shaped eccentric disk is as follows. Because the contact area between the rotating disk and the eccentric disk can be increased,
The eccentric distance is less likely to shift even under vibration. Since almost no gap is formed between the rotating disc and the eccentric disc, foreign matter such as cutting chips does not enter the gap between them. Since the eccentric shaft moves on an arc-shaped trajectory, even if a centrifugal force acts on the eccentric disk, the position of the eccentric shaft is unlikely to shift. Good durability and high reliability.

Next, a balance weight interlocking mechanism attached to the sander 10 will be described. The disk-shaped polishing pad 12 maintains a rotational balance around an eccentric shaft 15 as an attachment shaft in an initial setting. However, when the “eccentric distance” is gradually increased from a zero (zero) state by rotating the fixing means B1 (see FIG. 4), the overall rotational balance of the polishing unit 102 gradually deteriorates greatly. Will be.

Therefore, it is necessary to provide a balance weight interlocking mechanism for automatically preventing such a loss of balance in conjunction with the operation of the eccentric distance adjusting device. In particular, the "eccentric distance" is increased. Required for a tool that can be removed.

FIGS. 5 to 9 show the structure of the balance weight interlocking mechanism C1 attached to the sander 10. FIG. As shown in FIG. 5, the balance weight interlocking mechanism C1 includes an eccentric
A cylindrical balance weight 21 is attached to a worm wheel 17 which rotates integrally with the worm wheel 17. A crank pin 22 is fixed to the upper surface of the balance weight 21, and the crank pin 22 is rotatably attached to the worm wheel 17. On the other hand, a locking pin 23 is fixed to the lower surface of the balance weight. The locking pin 23 is fitted in an arc-shaped guide groove 24 formed in the inner bottom surface 11b of the turntable 11.

When the eccentric 13 rotates, the crankpin 2
The balance weight 21 interlocks with the movement of the balance weight 2. At this time, the movement direction of the balance weight 21 is
And the guide groove 24. That is, when the locking pin 23 moves in the direction of the arrow s in FIG. 5 along the guide groove 24 with the rotation of the eccentric disc 13, the balance weight 21 draws an arc-shaped trajectory in a direction away from the eccentric disc 13. While moving. In addition, the locking pin 23 is
, The balance weight 21 moves while drawing an arc-shaped trajectory in a direction to be drawn to the eccentric plate 13.

Here, the mounting positions of the crank pin 22 and the locking pin 23 and the shape of the guide groove 24 are set such that the balance weight 21 moves along an arc-shaped locus when the eccentric disk 13 rotates. It can be determined according to the following procedures A to D. A. Independent members that rotate together with the drive shaft 4 (rotary disk 11, polishing pad 12, abrasive material 12a, eccentric disk 13, eccentric shaft 15, bearing 16, worm wheel 17, worm 18, balance weight 21, crank pin 22
And the position of each center of gravity of the locking pin 23) is obtained (see FIGS. 2 and 5). B. As shown in FIG. 9, the plane H includes the rotation axis P of the drive shaft 4 and does not include the respective centers of gravity of the independent members (excluding the center of gravity located on the rotation axis P of the drive shaft 4). Each center of gravity of the independent member is divided into an eccentric shaft side center of gravity group and a center of gravity group opposite to the eccentric shaft 15 (hereinafter, referred to as a non-eccentric shaft side center of gravity group). Although the position of the center of gravity of each independent member is not shown in FIG. 9, the center of gravity of the bearing 16 is located on the rotation axis P of the drive shaft 4 and is not included in any of the groups of centers of gravity. In addition, since the rotating disk 11 has the guide concave portion 14 for accommodating the eccentric disk 13, the center of gravity is shifted from the rotation axis P. C. The respective combined centroids W1 and W2 of the eccentric shaft side center of gravity group and the non-eccentric shaft side center of gravity group are obtained. However, for convenience of description, in FIGS. 5 to 9, the combined center of gravity W1 of the eccentric shaft side center of gravity coincides with the center of gravity of the eccentric shaft 15, and the combined center of gravity W2 of the non-eccentric shaft side center of gravity coincides with the center of gravity of the balance weight 21. Is shown. D. When the eccentric disc 13 rotates, the following relationship is established between the combined center of gravity W1 of the eccentric shaft side center of gravity group and the combined center of gravity W2 of the non-eccentric shaft side center of gravity group, W1 · L1 = W2 / L2, where W1: eccentric shaft side Weight on the combined center of gravity W1 of the center of gravity group L1: Distance between the combined center of gravity W1 of the eccentric shaft side center of gravity group and the rotation axis P of the drive shaft 4 W2: Weight on the combined center of gravity W2 of the non-eccentric shaft side center of gravity group L2: Non-eccentricity The crank pin 22 and the locking pin 23 are arranged so as to satisfy the distance between the combined center of gravity W2 of the shaft side center of gravity group and the rotation axis P of the drive shaft 4.
And the shape of the guide groove 24 are selected. That is, as a result of satisfying such a relationship, when the eccentric disk 13 rotates, the balance weight 21 moves along a circular locus, and the center of the rotational balance of the rotary disk 11 coincides with the rotation axis P of the drive shaft 4. This prevents useless vibration of the polishing pad 12 and the like.

Next, how to use the sander 10 and the operation of the eccentric distance adjusting device A1 and the balance weight interlocking mechanism B1 will be described. First, as shown in FIG. 4, in a state where the index 19 indicates 0 (zero) on the scale and the eccentric board 13 is rotated to a position where “eccentric distance” (“orbit diamond”) becomes 0 (zero). As shown in FIG. 6, the mounting center c of the eccentric shaft 15 matches the rotation center a of the turntable 11.

At this time, as shown in FIG. 6, the axis (center of gravity) of the balance weight 21 is located on a line connecting the crank pin 22 and the locking pin 23, and the locking pin 23 is located in the guide groove 24. Contact one end of And in this state,
The center of gravity of the polishing section 102 coincides with the center of rotation a of the rotating disk 11, that is, the axis of the drive shaft 4.

Therefore, when the motor 1 of the main body 101 is started, the rotation balance is maintained around the drive shaft 4, the polishing section 102 rotates quietly, and the polishing material 12a operates gently. The body 3 of the polishing tool 10 is gripped, and the abrasive 12
The manner of the polishing operation performed by bringing a into contact with the object to be polished is similar to that of the conventional polishing tool, and therefore, the description is omitted.

Next, FIG. 7 shows that the eccentric disc 13 is
In contrast, a state in which the value of “orbit diagram” is set to <4> by rotating in the direction of arrow f. As the eccentric 13 rotates, the crank pin 22 pushes the balance weight 24 in the direction of arrow g. With this movement of the balance weight 21, the locking pin 23 projecting from the lower surface of the balance weight 21 moves in the guide groove 24 of the turntable 11 to the position shown in the drawing, and fixes the balance weight 21 at this position.

Thus, in the state shown in FIG.
Around the eccentric shaft 15 concentrically, in other words, the abrasive material 12a that has been rotating in a fixed position,
The turning motion is performed with the turning radius set to the "eccentric distance", and effective polishing can be performed. Even if the "eccentric distance" changes, the balance material 21 is displaced to the position shown in FIG. 7 to smoothly eccentrically move the abrasive 12a around the drive shaft 4 in a state where the rotational balance is well balanced. It can be rotated (turned).

FIG. 8 shows a state in which the eccentric disk 13 is rotated in the direction of arrow f with respect to the rotary disk 11 to further increase the "eccentric distance". At this time, in conjunction with the rotation of the eccentric disk 13, the balance weight 21
The rotation of the crank pin 22
As shown in the drawing, the polishing unit 102
A new loss of rotational balance is prevented.

As described above, the sander 10 of this embodiment is
According to this, the eccentric plate 13 is appropriately rotated and operated,
"Eccentric distance", that is, "orbit diagram" can be very easily and quickly changed to a desired value. Moreover, since the rotation balance is prevented from being lost due to the movement of the eccentric shaft, the workability is not impaired.

Thus, the polishing characteristics of the polishing tool 102,
In other words, the polishing trajectory of the abrasive 12a can be changed widely according to the properties of the object to be polished, the purpose of polishing, the degree of progress of polishing, and the like. Therefore, as mentioned at the beginning,
If necessary, when it is desired to change the polishing characteristics of the polishing tool, the polishing material 12 is extremely troublesome, time-consuming, and time-consuming.
It is not necessary to replace a with another type.

For example, from the start of polishing, a fine polishing material 12a for finishing is attached and placed, and the "eccentric distance" is initially set.
By increasing the length of the polishing material, rough polishing is performed in a state where the low polishing efficiency of the polishing material 12a is sufficiently compensated, and as the polishing proceeds, the “eccentric distance” is shortened. It is possible to achieve the desired polishing accuracy with much less labor and a shorter time than the conventional method of replacing in the middle. In this case, since an abrasive cloth or paper having a coarse abrasive particle size is not used, there is also an additional effect that there is no fear that the coarse abrasive particle will damage the polished surface deeply.

A buff is attached to the polishing pad 12,
When polishing the painted surface, reduce the "eccentric distance" for dark colored painted surfaces where scratches are easily visible, and increase the "eccentric distance" for light colored painted surfaces that are less noticeable to enhance the polishing effect. Such a flexible switching operation can be performed almost instantaneously.

Next, a second embodiment of the present invention is shown in FIG. In the second embodiment, the fixing means B2 of the eccentric disk 13 is constituted by free nuts 31, 33 and bolts 32. That is, the fixing means B2 of the second embodiment is provided with free nuts 31 and 33 inside the turntable 11,
Bolts 32 are fitted into these nut holes. A knob 34 is provided at the tip of a bolt 32 protruding outside the turntable 11.
Is fixed.

The bolt 32 of the fixing means B2 is
By rotating the eccentric disk 13 in either the left or right direction according to 4, the eccentric disk 13 can be rotated by a predetermined angle in a desired direction. According to the fixing means B2 of the second embodiment, the eccentric plate 13 can be quickly switched to a predetermined rotating position without using a tool such as a wrench with a simple structure.

Next, a third embodiment of the present invention is shown in FIGS. In the third embodiment, the fixing means B3 has a pin structure. A flange 35 is slidably attached to the axial end of the turntable 11. The flange 35 is provided with a movable weight 36 a slidably with respect to the outer peripheral side surface of the turntable 11. A fixed weight 36b is slidably fixed to the flange 35 on the outer peripheral side surface of the turntable 11. Auxiliary plate 13a fixed to the upper surface of eccentric plate 13
Has an arc-shaped locking groove 13b.
A locking pin 38 extending to the upper surface of the moving weight 36a is inserted into 3b. When the eccentric disc 13 is rotated, the locking pin 38 is restricted by the locking groove 13b and the moving weight 36a
And the circumferential distance of the fixed weight 36b is adjusted to a predetermined length. The moving weight 36a and the fixed weight 36b are adapted to adjust the rotational balance by a combination of the moving weight and the fixed weight 36b, similarly to the moving weight and the fixed weight of the fourth embodiment described later. Fixed weight 36
a inside the fixed pin 37 and the coil spring 3
8 are stored (see FIG. 12). One end of the fixing pin 37 is inserted into the positioning hole H of the flange 35 by the urging force of the coil spring 38. A lever 39 is attached to the other end of the fixing pin 37 protruding from the upper surface of the fixing weight 36b by a snap ring 39a. When adjusting the eccentric distance, when the lever 39 is pushed down in the direction of the arrow in FIG. 12, the fixing pin 37 moves upward against the urging force of the coil spring 38, and the tip of the pin comes off the positioning hole H. Then, in this state, the fixing pin 3
7 until the positioning hole H is switched to the predetermined positioning hole H.
Is rotated. When the tip of the fixing pin 37 reaches the predetermined positioning hole H, the pin tip is pushed into the positioning hole H by the urging force of the coil spring 38, and the eccentric disc 13 is locked at a predetermined rotation position.

According to the third embodiment, the eccentric distance can be switched very easily by pressing the lever 39 and turning the eccentric plate 13. Further, since the fixing pin 37 is fitted into the predetermined positioning hole H, the rotational position of the eccentric disc 13 does not shift even if it receives vibration or the like.

In the structure of the third embodiment, the reason why the flange 35 is provided on the eccentric disk 13 is that the fixing pin 37 is disposed in the axial direction with respect to the rotary disk 11. When the fixing pin 37 is arranged in the radial direction of the turntable 11,
During rotation, the fixing pin 37 is easily affected by the centrifugal force, and when the fixing pin 37 is attached to the turntable 11, the tip of the fixation pin 37 easily projects to the outer peripheral side surface of the turntable 11. For this reason, as a configuration in which the fixing pin 37 is arranged in the radial direction of the rotating disk 11, for example, a configuration in which the tip of the pin is pressed by a driver or the like to release the fitting between the pin and the pin hole is adopted. Therefore, the operation of switching the eccentric distance is easily troublesome. On the other hand, if the positioning hole H is provided in the flange 35 and the fixing pin 37 is arranged in the axial direction of the turntable 11, a lever or the like can be easily attached to the tip of the pin, and the operation of switching the eccentric distance becomes easy.

FIGS. 13 and 14 show a modification of the third embodiment. In the example shown in FIG. 13, a large diameter portion 39 b is provided at the end of the fixing pin 37 instead of the lever 39. The large diameter portion 39 b is pressed against the upper surface of the guide 36 by the urging force of the coil spring 38. When switching the eccentric distance, the large-diameter portion 39b is pinched and lifted in the direction of the arrow in FIG.

In the example shown in FIG. 14, a push-up tool 39c is provided at the tip of the fixing pin 37 instead of the lever 39. The tip of the push-up tool 39c is a rolling surface M that is curved in an arc shape. From the state of FIG. 14, the push-up tool 39c
When the is lifted upward, the rolling surface M rides on the upper surface of the guide 36, and the push-up tool 39 c stands up with respect to the upper surface of the guide 36, and lifts the fixing pin 37. As described above, also in the above-described modified example, the operator can quickly and reliably switch the eccentric distance with bare hands without using a special tool.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.
0 is shown. In the fourth embodiment, the balance weight interlocking mechanism C
No. 4 uses two balance weights (fixed weight 41 and movable weight 43). As shown in FIG. 15, a semicircular fixed weight 41 and a movable weight 43 are provided on the bottom of the turntable 11. The fixed weight 41 is fixed to the inner bottom surface 11 b of the turntable 11. The movable weight 43 is rotatably mounted on the center shaft 42 at a position slightly above the fixed weight 41. The fixed weight 41 and the moving weight 43 are both set to the same weight.

A locking pin 44 is fixed to a lower end surface of the worm wheel 17 which rotates integrally with the eccentric plate 13. The locking pin 44 is fitted in an arc-shaped guide groove 45 formed at a predetermined position of the moving weight 43. When the eccentric disc 13 is rotated, the locking pin 44 pushes the moving weight 43 in the guide groove 45 in the direction of the arrow, and the moving weight 43 moves following the turning motion of the eccentric disc 13. At this time, the locking pin 44 slides in the guide groove 45.

The moving position of the moving weight 43 is regulated by the sliding position of the locking pin 44 in the guide groove 45. That is, the moving weight 43 rotates with a predetermined phase difference with respect to the rotation angle of the eccentric disk 13.

Here, the mounting position of the locking pin 44 and the shape of the guide groove 45 are such that the moving weight 43 moves along an arc-shaped locus when the eccentric disk 13 rotates.
It can be determined according to the following procedure. A. Independent members (rotary disk 11, polishing pad 12, abrasive material 12a, eccentric disk 13, eccentric shaft 15, bearing 16, worm wheel 17, worm 18, fixed weight 41, central shaft 42, moving together with the drive shaft 4) The position of each center of gravity of the weight 43 and the locking pin 44 is obtained (FIG. 2).
And FIG. 15). B. As shown in FIG. 9, the plane H includes the rotation axis P of the drive shaft 4 and does not include the respective centers of gravity of the independent members (excluding the center of gravity located on the rotation axis P of the drive shaft 4). Each center of gravity of the independent member is divided into an eccentric shaft side center of gravity group and a non-eccentric shaft side center of gravity group. However, the fixed weight 41 and the moving weight 43 are considered as one independent member in total, and the combined center of gravity of the two is used as the position of the center of gravity of the balance weight. Although the position of the center of gravity of each independent member is not shown in FIG.
Is located on the rotation axis P of the drive shaft 4 and is not included in any of the groups of centers of gravity. In addition, the turntable 11
The center of gravity of the guide recess 14 is shifted from the rotation axis P because the guide recess 14 accommodates the eccentric disk 13. C. The respective combined centroids W1 and W2 of the eccentric shaft side center of gravity group and the non-eccentric shaft side center of gravity group are obtained. 9 and FIG.
In FIGS. 5 to 20, the composite center of gravity W1 of the eccentric shaft side center of gravity coincides with the center of gravity of the eccentric shaft 15, and the composite center of gravity W of the non-eccentric shaft side center of gravity group.
2 shows a case where the number 2 coincides with the combined center of gravity of the fixed weight 41 and the moving weight 43. D. When the eccentric disc 13 rotates, the following relationship is established between the combined center of gravity W1 of the eccentric shaft side center of gravity group and the combined center of gravity W2 of the non-eccentric shaft side center of gravity group, W1 · L1 = W2 / L2, where W1: eccentric shaft side Weight on the combined center of gravity W1 of the center of gravity group L1: Distance between the combined center of gravity W1 of the eccentric shaft side center of gravity group and the rotation axis P of the drive shaft 4 W2: Weight on the combined center of gravity W2 of the non-eccentric shaft side center of gravity group L2: Non-eccentricity The mounting position of the locking pin 44 and the shape of the guide groove 45 are selected so as to satisfy the distance between the combined center of gravity W2 of the shaft side center of gravity group and the rotation axis P of the drive shaft 4. That is, as a result of satisfying such a relationship, when the eccentric disk 13 rotates, the moving weight 43 moves along a circular locus, and the center of the rotational balance of the rotary disk 11 coincides with the rotation axis P of the drive shaft 4. This prevents useless vibration of the polishing pad 12 and the like.

Next, the operation of the balance weight interlocking mechanism C4 will be described with reference to FIGS. First, FIGS. 15 and 18 show “eccentric distance” (“orbit diamond”).
Shows a state when the rotational position of the eccentric disk 13 is set so that the value of the eccentric disk 13 becomes zero. The mounting center c of the eccentric shaft 15 overlaps the rotation center a of the turntable 11.

At this time, the moving weight 43 is located at a symmetrical position farthest from the fixed weight 41 as shown in FIG. In this state, the combined center of gravity of the fixed weight 41 and the movable weight 43 also overlaps the rotation center a of the turntable 11. Therefore, the polishing material 12a does not pivot, and the polishing unit rotates quietly with a good rotational balance.

FIGS. 16 and 19 show a state in which the rotational position of the eccentric disk 13 is set so that the value of "orbit diagram" becomes <4>. At this time, the moving weight 43 moves to the position shown in FIG. 19 in accordance with the movement of the eccentric disk 13, and maintains the rotational balance of the polishing unit.

FIGS. 17 and 20 show a state in which the rotational position of the eccentric disk 13 is set so that the value of the "orbit diagram" becomes the maximum value <6>. At this time, FIG.
As shown in (2), the moving weight 43 overlaps directly above the fixed weight 41, and the moving weight 43 is located at a position farthest from the mounting center c. As a result, the rotational balance of the polishing unit when the eccentric distance is the longest is maintained.

As described above, the balance weight interlocking mechanism C4 of the fourth embodiment comprises a fixed weight 41 and a movable weight 43.
By this combination, it is possible to prevent the rotation balance from being lost when the eccentric disk 13 rotates. For example, when it is difficult to attach the balance weight due to the presence of a shaft member or the like in the weight movement direction using only the balance weight alone, if the fixed weight 41 and the movable weight 43 are used as in the fourth embodiment, The balance can be adjusted relatively easily by avoiding interference of members and the like. In addition, since the fixed weight 41 and the movable weight 43 are housed inside the rotating disk 11, the entire apparatus can be lightened and compacted, and an assembling strength enough to withstand a strong centrifugal force can be obtained. .

Next, a fifth embodiment of the present invention is shown in FIGS. In the fifth embodiment, the present invention is applied to a high-speed forward / reverse inversion sander (polisher). An electric motor 52 is housed in a body 51 of the sander 50. A polishing pad 56a is attached to a forward end portion of a reversing shaft 56 extending below the body 51. On the front surface of the polishing pad 56a, an abrasive such as an abrasive cloth, paper, or a buff is detachably attached. An eccentric shaft 54 is provided at a position away from the motor drive shaft 53 by a predetermined distance. As shown in FIG. 22, the tip of the eccentric shaft 54 fits into the slide groove M of the swing lever 55. The end of the swing lever 55 is the forward / reverse reversing shaft 5
6 fixed. When the motor 52 is driven, the eccentric shaft 54 rotates with the rotation of the drive shaft 53, and the swing lever 5
5 reciprocates within a predetermined angle range, and repeats the normal rotation / reversal of the polishing pad 56a via the reversing shaft 56.

A rotary disk 57 is fixed to the drive shaft 53. An eccentric disk 5 is provided on the end face of the rotary disk 57 opposite to the drive shaft.
8 is rotatably mounted. The eccentric shaft 54 is fixed at a position away from the center of rotation of the eccentric disk 58 by a predetermined distance. When the eccentric disk 58 is rotated, the eccentric distance between the eccentric shaft 54 and the drive shaft 53 changes.

As shown in FIG. 21, a worm wheel 58a and a worm 59 are provided inside the turntable 57. The worm wheel 58a is formed integrally with the end face of the eccentric disk 58. The worm 59 engages with the worm wheel 58a and stops the eccentric disk 58 at a predetermined rotation position. When adjusting the eccentric distance between the drive shaft 53 and the eccentric shaft 54, when the worm 59 is rotated in a predetermined direction, the eccentric shaft 54 moves together with the worm wheel 58a to a predetermined rotation position. According to the fifth embodiment, by changing the eccentric distance between the drive shaft 53 and the eccentric shaft 54, the forward / reverse inversion angle range of the polishing pad 56a can be adjusted. That is, as the eccentric distance increases, the slide groove M
, The sliding distance of the eccentric shaft 54 is increased, and the swing angle of the swing lever 55 is increased.
In addition, the forward / reverse inversion angle of the polishing pad 56a increases. Therefore, according to the sander 50, polishing can be performed while adjusting the reversal angle of the buff surface in accordance with the finishing accuracy of the polished surface.

Next, a sixth embodiment of the present invention is shown in FIGS. In the sixth embodiment, the present invention is applied to an orbital sander. Orbital sander 61
The electric motor 62 is housed in the body 61. An eccentric shaft 64 is provided at a predetermined distance from a drive shaft 63 of the electric motor 62.
A polishing pad 66 is attached via 6a (see FIG. 24). On the front surface of the polishing pad 66, polishing cloth / paper,
An abrasive such as a buff is detachably attached. At four corners of the polishing pad 66, support columns 65 made of a flexible material are provided.
Is formed. Each support column 65 is fixed to a predetermined position of the body 61. When the electric motor 62 is driven, the drive shaft 6
The rotation force of No. 3 is transmitted to the polishing pad 66 via the eccentric shaft 64. The polishing pad 66 vibrates at a predetermined width with the rotation of the eccentric shaft 64, and is brought into contact with the surface to be polished.

A rotary disk 67 is fixed to the drive shaft 63. An eccentric plate 68 is rotatably attached to the end surface of the turntable 67 opposite to the drive shaft 63. This eccentric 6
An eccentric shaft 64 is fixed at a position away from the rotating shaft 8 by a predetermined distance. When the eccentric disk 68 is rotated, the eccentric distance between the drive shaft 63 and the eccentric shaft 64 changes.

As shown in FIG. 23, a worm wheel 68a and a worm 69 are provided inside the turntable 67. The worm wheel 68a is formed integrally with the end face of the eccentric disk 68. The worm 69 engages with the worm wheel 68a to stop the eccentric disk 68 at a predetermined rotation position. When adjusting the eccentric distance between the drive shaft 63 and the eccentric shaft 64, when the worm 69 is rotated in a predetermined direction, the eccentric shaft 64 moves together with the worm wheel 68a to a predetermined rotation position.

According to the sixth embodiment, the vibration width of the polishing pad 66 can be adjusted by changing the eccentric distance. That is, as the eccentric distance increases, the turning radius of the eccentric shaft 64 increases, and the vibration width of the polishing pad 66 increases. For example, when the polished surface is to be roughly cut, the eccentric distance can be increased, and when the polished surface is to be cut smoothly, the eccentric distance can be reduced.

Next, a seventh embodiment of the present invention is shown in FIGS. In the seventh embodiment, the present invention is applied to a linear movement type sander (polisher). In the sander 70, an electric motor 72 is housed in a body 71. A drive gear 74 for rotating a turntable 77 is fixed to a drive shaft 73 of the electric motor 72. A gear that meshes with the drive gear 74 is formed on the outer peripheral end of the turntable 77. The rotating disk 77 includes a rotating shaft 77 supported inside the body 71.
fixed to a. An eccentric shaft 75 is provided at a position away from the rotation shaft a by a predetermined distance. The locking plate 76a of the polishing pad 76 is fitted to the tip of the eccentric shaft 75. The polishing pad 76 is movable in the front-rear direction (the left-right direction in FIG. 25) by a roller R attached to the body 71. On the front surface of the polishing pad 76, an abrasive such as an abrasive cloth, paper, or a buff is detachably attached. Note that 71a, 7
1b is a handle for operation.

When the electric motor 72 is operated, the drive shaft 73
The rotational force of the drive gear 74, the rotary disc 77 and the eccentric shaft 75
Is transmitted to At this time, the eccentric shaft 75 rotates while sliding in the groove between the locking plates 76a, and reciprocates the polishing pad 76 within a predetermined length range.

An eccentric plate 78 is rotatably mounted on the end surface of the rotary plate 77 opposite to the rotary shaft 73. An eccentric shaft 75 is fixed at a position away from the center of rotation of the eccentric disk 78 by a predetermined distance. When the eccentric 78 is rotated, the eccentric distance between the rotation shaft 77a and the eccentric shaft 75 changes.

As shown in FIG. 25, a worm wheel 78a and a worm 79 are provided inside the turntable 77. The worm wheel 78a is formed integrally with the end face of the eccentric 78. The worm 79 engages with the worm wheel 78a and stops the eccentric 78 at a predetermined rotation position. When adjusting the eccentric distance between the rotating shaft 77a and the eccentric shaft 75, when the worm 79 is rotated in a predetermined direction,
The eccentric shaft 75 moves to a predetermined rotation position together with the worm wheel 78a.

According to the seventh embodiment, the stroke of the reciprocating motion of the polishing pad 76 can be increased or decreased by adjusting the eccentric distance between the rotary shaft 77a and the eccentric shaft 75. Thus, the polishing operation can be performed efficiently by adjusting the reciprocating distance of the buff surface according to the processing surface.

Next, an eighth embodiment of the present invention is shown in FIGS. In the eighth embodiment, the present invention is applied to an electric saw. In the electric saw 80, an electric motor 82 is housed in a body 81. The helical gear formed on the drive shaft 83 of the electric motor 82 meshes with the gear on the outer periphery of the turntable 87. The turntable 87 is provided with a rotating shaft 8
7a so as to be rotatable. Rotating shaft 87a
An eccentric shaft 84 is provided at a predetermined distance from the eccentric shaft 84, and a band-shaped saw blade 86 is fixed to the eccentric shaft 84. Eccentric shaft 8
The tip of 4 is slidably fitted in a groove of a locking member 86a fixed to a predetermined position of the saw blade 86. Electric motor 82
Is operated, the rotational force of the drive shaft 83 is transmitted to the eccentric shaft 84 via the eccentric disk 88. The eccentric shaft 84 is provided with a locking member 86
The saw blade 86 is moved up and down while sliding in the groove of a.

An eccentric disk 88 is rotatably mounted on the end surface of the rotary disk 87 opposite to the rotation shaft 87a. An eccentric shaft 84 is fixed at a position away from the center of rotation of the eccentric disk 88 by a predetermined distance. When the eccentric disc 88 is rotated, the eccentric distance between the rotating shaft 87a and the eccentric shaft 84 changes.

As shown in FIG. 27, a worm wheel 88a and a worm 89 are provided inside the turntable 87. The worm wheel 88a is formed integrally with the end surface of the eccentric disk 88. The worm 89 engages with the worm wheel 88a to stop the eccentric disk 88 at a predetermined rotation position. When adjusting the eccentric distance between the rotating shaft 87a and the eccentric shaft 84, when the worm 89 is rotated in a predetermined direction,
The eccentric shaft 84 moves to a predetermined rotation position together with the worm wheel 88a.

According to the eighth embodiment, the saw blade 86 is formed by changing the eccentric distance between the rotary shaft 87a and the eccentric shaft 84.
It is possible to adjust the stroke at the time of reciprocating motion. That is, as the stroke increases, the cutting length of the saw blade 86 increases. For example, by adjusting the eccentric distance according to the hardness of the processing material or the like, an efficient cutting operation can be performed.

In the fifth to eighth embodiments,
The balance weight interlocking mechanism is not provided because the rotation of the eccentric disc has little effect on the rotational balance of the rotary disc. However, a balance weight interlocking mechanism can be provided if necessary.

Further, in each of the above embodiments, the object of the present invention can be achieved even if the detailed structure is appropriately changed in design.
For example, any of an air motor and an electric motor can be adopted as the rotary drive source. Further, the shape and arrangement of the balance weight may be changed to various shapes and arrangements as long as they follow the above-described operation principle.

[0067]

As apparent from the above description, the eccentric distance adjusting device for a tool having the eccentric mechanism according to the present invention exhibits various excellent effects in practical use as follows. (A) The distance between the drive shaft and the eccentric shaft of the tool, that is,
"Eccentric distance" can be adjusted from zero to a desired value by a very simple operation. (B) When it is desired to change the polishing characteristics or cutting characteristics of the tool, another type is used as in the past. It is extremely troublesome to replace the material with an abrasive or a cutting material, and it is not necessary to perform an extremely laborious and time-consuming operation. (C) With the change in the eccentric distance, the rotational balance of the rotating disk is lost, and the problem that the entire tool vibrates can be reliably eliminated by the attached balance weight interlocking mechanism.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a sander (polisher) according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing a sander (polisher) according to the first embodiment of the present invention.

FIG. 3 is a plan view showing a rotary plate, an eccentric plate and fixing means of a sander (polisher) according to the first embodiment of the present invention.

FIG. 4 is a plan view of a turntable showing an example of display means for notifying a value of an eccentric distance of a sander (polisher) according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a configuration of a rotary plate, an eccentric plate, and a balance weight of a sander (polisher) according to the first embodiment of the present invention.

FIG. 6 is a plan view of a rotary disk showing displacement states of the eccentric disk and the balance weight when the eccentric distance of the sander (polisher) according to the first embodiment of the present invention is set to <0>.

FIG. 7 is a plan view of a rotary disk showing the state of displacement of the eccentric disk and the balance weight when the eccentric distance of the sander (polisher) according to the first embodiment of the present invention is set to <4>.

FIG. 8 is a plan view of a rotating disk showing displacement states of the eccentric disk and the balance weight when the eccentric distance of the sander (polisher) according to the first embodiment of the present invention is increased from <4>.

FIG. 9 is a schematic diagram for explaining a positional relationship between an eccentric disk of a sander (polisher) and a balance weight according to the present invention.

FIG. 10 is a perspective view schematically showing a structure of a sander (polisher) fixing means according to a second embodiment of the present invention.

FIG. 11 is a partial plan view showing fixing means of a sander (polisher) according to a third embodiment of the present invention.

FIG. 12 is a partial side view showing a fixing means of a sander (polisher) according to a third embodiment of the present invention.

FIG. 13 is a partial side view showing a modification of the fixing means of the sander (polisher) according to the third embodiment of the present invention.

FIG. 14 is a partial perspective view showing a modification of the fixing means of the sander (polisher) according to the third embodiment of the present invention.

FIG. 15 is a perspective view showing a schematic configuration of a rotary plate, an eccentric plate and a balance weight of a sander (polisher) according to a fourth embodiment of the present invention, in which the value of the eccentric distance is <0>. is there.

16 is a diagram corresponding to FIG. 15, showing a state where the value of the eccentric distance is <4>.

FIG. 17 is a diagram corresponding to FIG. 15, showing a state where the value of the eccentric distance is <6>.

FIG. 18 is a plan view showing a schematic configuration of a rotary disk and an eccentric disk of a sander (polisher) according to a fourth embodiment of the present invention, in which the value of the eccentric distance is <0>.

19 is a diagram corresponding to FIG. 18, showing a state where the value of the eccentric distance is <4>.

FIG. 20 is a diagram corresponding to FIG. 18, showing a state where the value of the eccentric distance is <6>.

FIG. 21 is a side view showing a sander (polisher) according to a fifth embodiment of the present invention.

FIG. 22 is a partial perspective view showing a sander (polisher) according to a fifth embodiment of the present invention.

FIG. 23 is a side view showing a sander (polisher) according to a sixth embodiment of the present invention.

FIG. 24 is a partial perspective view showing a sander (polisher) according to a sixth embodiment of the present invention.

FIG. 25 is a side view showing a sander (polisher) according to a seventh embodiment of the present invention.

FIG. 26 is a partial perspective view showing a sander (polisher) according to a seventh embodiment of the present invention.

FIG. 27 is a side view showing an electric saw according to an eighth embodiment of the present invention.

FIG. 28 is a partial perspective view showing an electric saw according to an eighth embodiment of the present invention.

FIG. 29 is an external perspective view showing a polishing tool according to a conventional example.

FIG. 30 is a partial side view schematically showing a configuration of a conventional polishing tool.

[Explanation of symbols]

A1 Eccentric distance adjustment device B1 Fixing means C1 Balance weight interlocking mechanism 1 Air motor 2 Handle 3 Body 4 Drive shaft 5 Actuator 7 Cover body 8 Stop ring 10 Sander (polisher) 11 Rotating disk 15 Eccentric shaft 12a Polishing pad 13 Eccentric disk 14 Guide recess 11a Mounting shaft 16 Bearing 17 Worm wheel 18 Worm 18a Hexagon hole 21 Balance weight 22 Crank pin 23 Locking pin 24 Guide groove 101 Main body 102 Polishing part a Rotation center of rotary disk 11 (center of drive shaft 4) b Eccentric disk 13 The center of rotation of the eccentric shaft 15 The mounting center of the eccentric shaft 15 H Plane P The rotating shaft W1 The weight applied to the combined center of gravity of the eccentric shaft side center of gravity L1 The distance between the combined center of gravity of the eccentric shaft side center of gravity and the rotating shaft of the drive shaft W2 Non-eccentric shaft Weight of composite center of gravity of side center of gravity group L2 Non-eccentric shaft side center of gravity group Distance of the rotation axis of the forming DCG shaft

Continuation of the front page (71) Applicant 398068440 Masaru Aono 1-6-153, Shimozato, Higashikurume-shi, Tokyo (72) Inventor Koji Kaneko 21st, Toyoda-ji, Sakae, Toyoyama-cho, Nishi-Kasugai-gun, Aichi Prefecture 72) Inventor Norimitsu Watanabe 3178 Ohira Masato, Numazu City, Shizuoka Prefecture (72) Inventor: Yutaka Yoshida 4903, Achisu-cho, Kishiki-gun, Yamaguchi Prefecture 9 (72) Inventor Masaru Aono, Higashi-Kurume, Tokyo 6-53 Shimozato F-term (reference) 3C034 AA08 BB62 DD20

Claims (3)

[Claims] 1. A tool having an eccentric mechanism for transmitting a rotational force of a drive shaft of a drive motor to a driven rotating member or a reciprocating member by an eccentric shaft, wherein the drive shaft of the drive motor is driven. A rotating disk that is rotated by a force, an eccentric disk rotatably provided at a predetermined distance from a rotation axis of the rotating disk, and an axial disk provided at a position separated from the rotation center of the eccentric disk by a predetermined distance. An eccentric shaft, and an eccentric mechanism, wherein the eccentric disk is fixed at a predetermined rotation position to thereby adjust an eccentric distance between the drive shaft and the eccentric shaft. Eccentric distance adjustment device for tool. 2. The balance weight according to claim 1, wherein a balance weight is provided at a position separated from the eccentric board by a predetermined distance so as to draw a predetermined arc-shaped trajectory with the rotation of the eccentric board. An eccentric distance adjusting device for a tool having an eccentric mechanism. 3. The eccentric distance adjusting device for a tool having an eccentric mechanism according to claim 2, wherein the arc-shaped trajectory is set according to the following procedures A to D. A. The positions of the respective centers of gravity of the rotating disk, the eccentric disk, the eccentric shaft, the fixing means, and other independent members that rotate integrally with the drive shaft are determined. B. The center of gravity of the independent member is shifted to the eccentric shaft side by a plane including the rotation axis of the drive shaft and excluding the respective centers of gravity of the independent member (excluding those located on the rotation axis of the drive shaft). It is divided into a center of gravity group and a center of gravity group opposite to the eccentric axis (hereinafter, referred to as a non-eccentric shaft side center of gravity group). C. The respective combined centroids of the eccentric shaft side center of gravity group and the non-eccentric shaft side center of gravity group are obtained. D. When the eccentric disk rotates, the following relationship is established between the combined center of gravity of the eccentric shaft side center of gravity group and the combined center of gravity of the non-eccentric shaft side center of gravity group: W1 · L1 = W2 · L2, where W1: the eccentric shaft Weight on the combined center of gravity of the side center of gravity group L1: Distance between the combined center of gravity of the eccentric shaft side center of gravity group and the rotation axis of the drive shaft W2: Weight on the combined center of gravity of the non-eccentric shaft side center of gravity group L2: The non-eccentricity The arc-shaped trajectory of the balance weight is determined so as to satisfy the distance between the combined center of gravity of the group of shaft-side centers of gravity and the rotation axis of the drive shaft.