JP7117832B2 - Polisher - Google Patents

Description

The present invention relates to a polisher for polishing, for example, a painted surface of an automobile body.

Conventionally, this kind of polisher is classified into the following three types according to the movement of the polishing pad. Three types are commonly called single action, double action, and gear action. The single-action type has a polishing pad that only rotates on its axis, and although it has a large polishing power, it is not suitable for final polishing. In both the double action type and the gear action type, the polishing pad rotates and revolves. In these types, the polishing pad undergoes two different rotational motions: revolution and rotation. Since there is a difference between the revolution and rotation speeds of the polishing pad, it is possible to achieve a higher quality finish compared to the single-action type.

In the double action type, the polishing pad is rotatable around a position eccentric to the rotation center of the drive shaft. As the drive shaft rotates, the polishing pad revolves around the center of rotation of the drive shaft, and along with the revolution, it also rotates due to the inertia or centrifugal force of the polishing pad and the frictional force of the bearing. . In the double-action type, when the polishing pad contacts the surface to be polished, the rotation of the polishing pad weakens due to the frictional resistance between the surface to be polished and the polishing pad. It will stop spinning. The double action type has the lowest polishing power among the three types and is suitable for final polishing. However, since the rotation of the polishing pad stops when the polishing pad is strongly pressed against the surface to be polished, it is not easy to obtain a stable polishing force.

On the other hand, the gear action type is a system in which a hypocycloid mechanism is used to drive the polishing pad with gears (Patent Document 1 below). In this method, since the polishing pad is attached to the external gear that meshes with the internal gear and is gear-driven, the rotation of the polishing pad does not stop even if the polishing pad comes into contact with the surface to be polished. Therefore, a stable polishing force can be easily obtained as compared with the double-action type, and the polishing force is increased compared with the double-action type. In addition, since the rotational trajectory of the polishing pad is not a unidirectional circular motion like a single action, but a series of small arcs, the finished quality of the polished surface is improved. Abrasive power is in the middle of the three types, making it suitable for intermediate finishing.

In the gear action type, the amount of eccentricity becomes the revolution radius. Therefore, increasing the amount of eccentricity increases the difference in the number of teeth between the internal gear and the external gear that meshes with it. As a result, the ratio of the rotational speed to the revolution speed (period) of the polishing pad increases. Generally, in order to obtain high polishing quality, a relatively large revolution radius is required. However, if the revolution radius is increased in the gear action type, the ratio of the rotation speed to the revolution speed will increase as described above. As a result, the momentum of the polishing pad increases and the polishing force becomes larger than necessary, making it unsuitable for use in work requiring intermediate or higher finish polishing quality. In this way, the gear action type cannot be designed with a degree of freedom because there is a correlation between the difference between the revolution speed and the rotation speed and the amount of eccentricity between the revolution shaft and the rotation shaft. That is, both a large amount of eccentricity (orbital radius) and a small continuous arc trajectory cannot be realized.

Japanese Patent Publication No. 4-48583

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and provides a polisher that can be designed with a high degree of freedom in terms of the ratio of revolution and rotation of the polishing pad while making use of the advantage of the gear action that the polishing force is stable. The task is to provide

The present invention has been made to solve the above problems, and a polisher according to the present invention comprises a fixed member, a drive shaft rotatably supported by the fixed member and driven to rotate by a drive source, and a drive shaft. A polisher comprising a polishing pad that revolves and rotates by rotation of a shaft, wherein the drive shaft has an eccentric support surface that is eccentric with respect to the center of rotation of the drive shaft by a predetermined eccentricity. An outer ring member having an internal gear is rotatably supported on the supporting surface via a bearing, and a detent mechanism is provided between the fixed member and the outer ring member to prevent rotation of the outer ring member and allow it to revolve. is provided, and a polishing pad is attached to a constituent member that constitutes a gear mechanism together with an internal gear and rotates.

In the polisher having this structure, the internal gear is provided eccentrically with respect to the drive shaft. Further, the outer ring member provided with the internal gear is in a state where it is prevented from rotating by the anti-rotation mechanism and only allowed to revolve. Therefore, by setting the eccentricity of the internal gear at the time of designing, the revolution radius of the polishing pad can be set large or small without considering the rotation. On the other hand, since the polishing pad is attached to the rotating member that constitutes the gear mechanism together with the internal gear, a stable polishing force can be obtained as in the case of the conventional gear action. Since the internal gear is eccentric as described above, a constant revolution radius can be obtained, so that the ratio of rotation speed to revolution speed of the polishing pad can be easily set in the gear mechanism at the time of design. In this way, by eccentrically configuring the outer ring member provided with the internal gear with respect to the drive shaft, it becomes possible to set the revolution and the rotation separately at the time of design. Therefore, for example, it is possible to reduce the ratio of the number of rotations of the polishing pad to the number of revolutions, and by setting it in this way, it is possible to obtain a continuous small circular arc locus while ensuring a large amount of eccentricity. As a result, it becomes possible to easily obtain high polishing quality.

In particular, it is preferable that the component is an external gear that meshes with the internal gear and has a rotation center that is eccentric with respect to the eccentric support surface by a predetermined eccentricity, and that the gear mechanism is configured as a hypocycloid mechanism. With such a two-stage eccentric configuration, the difference between the revolution speed and the rotation speed can be arbitrarily set, and high polishing quality can be easily obtained.

In addition, it is preferable that the anti-rotation mechanisms are arranged at three locations, so that the outer ring member is stabilized without wobbling, and the rotation of the polishing pad is also stabilized.

As described above, by configuring the internal gear eccentrically with respect to the drive shaft so that the internal gear only revolves, it is possible to obtain a stable grinding force similar to the conventional gear action. In addition, it is possible to design the polishing pad with a high degree of freedom regarding the ratio of revolution and rotation, and it is possible to easily obtain high polishing quality as compared with the conventional gear action.

1 is a cross-sectional view showing a polisher in one embodiment of the present invention; FIG. FIG. 2 is an enlarged view of a main portion of FIG. 1; AA sectional view of FIG. BB sectional view of FIG. FIG. 4 is a cross-sectional view of a main part of a polisher according to another embodiment of the present invention;

A polisher according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. FIG. 1 shows the overall structure of the polisher of this embodiment. First, the overall configuration of the polisher will be described. The polisher has a housing as a stationary member. The housing includes a head portion 1 positioned on the front side and a grip portion 2 extending rearward from the head portion 1 . One end of the head portion 1 is open, and a polishing pad 3 for polishing a surface to be polished such as a painted surface of an automobile is positioned outside the opening. Hereinafter, the one end side of the head portion 1 where the polishing pad 3 is positioned will be referred to as the lower side, and the other end side of the head portion 1 will be referred to as the upper side. The head portion 1 has a shape extending in the vertical direction as a whole, and the grip portion 2 has a shape extending in a horizontal direction, which is a direction substantially orthogonal to the head portion 1 . The extending direction of the grip portion 2 is defined as the front-rear direction, the head portion is defined as the front side, and the grip portion 2 is defined as the rear side.

The housing includes a main housing 4 , gear cases 5 a and 5 b and a dust cover 6 . The main housing 4 constitutes the upper half area of the head portion 1 and the grip portion 2 . The main housing 4 is preferably made of synthetic resin and formed by injection molding. The upper half area of the head portion 1 serves as a motor accommodating portion, and therefore the main housing 4 is composed of the motor accommodating portion and the grip portion 2 . A motor 7 as a drive source is housed in the motor housing. The motor accommodating portion has a cylindrical shape having a vertical axis, and the motor 7 is accommodated in the motor accommodating portion with the motor shaft 8 directed vertically. The upper end of the motor shaft 8 is rotatably supported by the main housing 4 via bearings 9 . The gripping portion 2 extends substantially horizontally rearward from a substantially central portion in the vertical direction of the head portion 1 , and the internal space communicates with the head portion 1 . A trigger switch 10 for stopping the operation of the motor 7 is provided on the lower surface of the grip portion 2 near the head portion 1 , and a trigger switch 10 for adjusting the rotational speed of the motor 7 is provided behind the trigger switch 10 . A dial-type speed controller 11 is provided. A power cord (not shown) extends rearward from the rear end of the grip portion 2 . A cordless type equipped with a battery may also be used.

Gear cases 5a and 5b are arranged below the motor accommodating portion. The gear cases 5a and 5b are composed of an upper gear case 5a and a lower gear case 5b, and a housing space is formed between the upper gear case 5a and the lower gear case 5b. FIG. 2 shows an enlarged view of the portion below the gear cases 5a and 5b. The lower end of the motor accommodating portion is open, and the lower portion of the motor shaft 8 protrudes downward from the opening by a predetermined length, and the lower portion of the motor shaft 8 enters the upper gear case 5a. A lower portion of the motor shaft 8 is rotatably supported by the upper gear case 5a via a bearing 12. As shown in FIG. A toothed portion (not shown) is formed on the outer peripheral surface of the lower end portion of the motor shaft 8 protruding downward from the bearing 12, and a reduction gear 13 is meshed with the toothed portion. The reduction gear 13 is housed in a housing space between the upper gear case 5a and the lower gear case 5b. The reduction gear 13 is attached and fixed to an upper portion of an intermediate shaft 14 as a drive shaft. The intermediate shaft 14 is horizontally spaced from the motor shaft 8 by a predetermined distance and is in parallel with the motor shaft 8 . That is, the intermediate shaft 14 extends vertically, and the reduction gear 13 rotates around the intermediate shaft 14 . Specifically, the intermediate shaft 14 is located on the front side of the motor shaft 8 . The intermediate shaft 14 receives driving force from the motor shaft 8 via the reduction gear 13 and rotates. An upper end portion of the intermediate shaft 14 is rotatably supported by the upper gear case 5a via a bearing 15, and an intermediate portion of the intermediate shaft 14 is rotatably supported by the lower gear case 5b via a bearing 16. The intermediate shaft 14 extends downward through the lower gear case 5b, and substantially the lower half of the intermediate shaft 14 protrudes downward from the lower gear case 5b.

The intermediate shaft 14 has a first eccentric support surface consisting of an outer peripheral surface having a center line eccentric with respect to the rotation center of the intermediate shaft 14 by a first eccentric amount at the lower portion, which is a portion that protrudes downward from the lower gear case 5b. and a second eccentric support surface 21 consisting of an inner peripheral surface having a center line eccentric to the center line of the first eccentric support surface 20 by a second eccentric amount. The first eccentric support surface 20 is positioned above, and the second eccentric support surface 21 is positioned below the first eccentric support surface 20 . The eccentric direction of the first eccentric support surface 20 with respect to the rotation center of the intermediate shaft 14 and the eccentric direction of the second eccentric support surface 21 with respect to the first eccentric support surface 20 are the same direction. Therefore, the second eccentric support surface 21 is eccentric with respect to the center of rotation of the intermediate shaft 14 by the eccentric amount obtained by adding the first eccentric amount and the second eccentric amount. The amount of eccentricity obtained by adding the first amount of eccentricity and the second amount of eccentricity will be referred to as the total amount of eccentricity.

An outer ring member 23 is rotatably supported outside the first eccentric support surface 20 via a bearing 22 . The outer ring member 23 is positioned below the lower gear case 5b. The outer ring member 23 is cylindrical as a whole, and its upper end is rotatably supported by the first eccentric support surface 20 via the bearing 22 . An internal gear 24 is provided at the lower end of the outer ring member 23 . The internal gear 24 is composed of a member separate from the outer ring member 23 , and is attached and fixed to the lower end portion of the outer ring member 23 from the lower side of the outer ring member 23 . However, the internal gear 24 may be configured integrally with the outer ring member 23 as one member.

The outer ring member 23 is configured to be rotatable relative to the first eccentric support surface 20 of the intermediate shaft 14, but does not itself rotate with respect to the housing, which is a fixed member, so that the intermediate shaft 14 rotates. Only revolve around the center. A detent mechanism is provided between the lower gear case 5b and the outer ring member 23 in order to prevent the rotation of the outer ring member 23 and allow only the revolution.

An eccentric pin 25 is provided between the lower gear case 5b and the outer ring member 23 as a detent mechanism. As shown in FIG. 4, the eccentric pins 25 are arranged at three locations around the intermediate shaft 14 at equal intervals in the circumferential direction. As shown in FIG. 2, the eccentric pin 25 consists of an upper portion and a lower portion. The lower portion of the eccentric pin 25 is eccentric with respect to the upper portion by a predetermined amount, and the upper portion and the lower portion of the eccentric pin 25 are parallel to each other and extend vertically. An upper portion of the eccentric pin 25 is rotatably supported by the lower gear case 5b via a bearing 26, and a lower portion of the eccentric pin 25 is rotatably supported by an upper end portion of the outer ring member 23 via a bearing 27. A bearing 26 that supports the upper portion of the eccentric pin 25 is arranged outside the bearing 16 that supports the intermediate portion of the intermediate shaft 14 with respect to the lower gear case 5b. A bearing 27 that supports the lower portion of the eccentric pin 25 is positioned outside the bearing 22 that supports the outer ring member 23 on the intermediate shaft 14 and is positioned near the outer peripheral portion of the outer ring member 23 . In this way, the outer ring member 23 is supported by the lower gear case 5b by means of the eccentric pins 25 at three locations in such a state that it cannot rotate but can revolve. Therefore, when the intermediate shaft 14 rotates, the outer ring member 23 revolves around the rotation center of the intermediate shaft 14 with the first eccentricity as the revolution radius. It is blocked by eccentric pins 25 at several points.

Below the first eccentric support surface 20, a large-diameter tubular portion 17 having an outer peripheral surface one step larger in diameter than the first eccentric support surface 20 is formed. A weight 30 is attached. The balance weight 30 rotates inside the outer ring member 23 together with the large-diameter cylindrical portion 17 of the intermediate shaft 14 . A second eccentric support surface 21 is formed on the inner peripheral surface of the large-diameter cylindrical portion 17 . A spindle shaft 32 is rotatably supported inside the second eccentric support surface 21 via a bearing 31 . The spindle shaft 32 has a center of rotation in the vertical direction, and its intermediate portion is supported by the second eccentric support surface 21 via a bearing 31 . Also, the upper end of the spindle shaft 32 reaches a position inside the first eccentric support surface 20 and is rotatably supported by the intermediate shaft 14 by a bearing 33 . The spindle shaft 32 rotates around the center of the second eccentric support surface 21 . Therefore, the center of rotation of the spindle shaft 32 is eccentric with respect to the center of rotation of the intermediate shaft 14 by a total amount of eccentricity. An external gear 34 is screwed to the spindle shaft 32 from below. The external gear 34 rotates integrally with the spindle shaft 32 and its center of rotation is the same as the center of rotation of the spindle shaft 32 . Therefore, the external gear 34 is eccentric with respect to the outer ring member 23 by the second eccentricity, and is also eccentric with respect to the internal gear 24 by the second eccentricity. As shown in FIG. 3, the external gear 34 meshes with the internal gear 24 from the inside.

The polishing pad 3 is detachably attached to the lower surface of the external gear 34 from below by screwing. A thin support plate 40 is attached to the upper surface of the polishing pad 3 , and the support plate 40 is positioned between the upper surface of the polishing pad 3 and the lower surface of the external gear 34 . A cylindrical dustproof cover 6 is attached to the outer peripheral surface of the lower end portion of the lower gear case 5b. The dustproof cover 6 extends downward from the lower end of the lower gear case 5b and covers the outer ring member 23 with a space therebetween. The lower end of the dustproof cover 6 is open, and the opening constitutes the lower end opening of the housing. A lower end portion of the dustproof cover 6 is located near the upper surface of the support plate 40 , and a dustproof sheet 41 is attached to the lower end surface of the dustproof cover 6 to fill the gap between the dustproof cover 6 and the support plate 40 . The polishing pad 3 has a larger diameter than the lower end portion of the dustproof cover 6 , and the outer peripheral portion of the polishing pad 3 protrudes outward from the lower end portion of the dustproof cover 6 . Therefore, the operator can visually confirm the position of the polishing pad 3 while performing the polishing work when viewed from above.

In the polisher constructed as described above, the rotation of the motor 7 is transmitted to the intermediate shaft 14 via the reduction gear 13 . Since the outer ring member 23 is eccentric with respect to the intermediate shaft 14 by the first eccentricity amount, the rotation of the intermediate shaft 14 causes the outer ring member 23 to revolve with a radius of the first eccentricity amount. Further, since the outer ring member 23 is prevented from rotating by the eccentric pin 25, the outer ring member 23 cannot rotate but only revolves. As the outer ring member 23 revolves in this manner, the internal gear 24 itself revolves. Therefore, the external gear 34 that meshes with the internal gear 24 and revolves while rotating revolves with a large revolution radius corresponding to the total eccentricity, and the polishing pad 3 also revolves with a large revolution radius at the same time. Further, since the internal gear 24 itself revolves, the revolution of the internal gear 24 can secure a certain amount of revolution radius of the polishing pad 3 .

Since the internal gear 24 is eccentric with respect to the intermediate shaft 14 and revolves with the first eccentricity, it is possible to separate the revolution and rotation of the polishing pad 3 in the design stage. It becomes possible. That is, the ratio of the number of revolutions of the polishing pad 3 to the number of revolutions can be arbitrarily set. For example, it is possible to reduce the ratio of the number of revolutions of the polishing pad 3 to the number of revolutions. By reducing this ratio, it is possible to obtain a continuous small arc trajectory while ensuring a large eccentricity, and it is possible to easily obtain high polishing quality. In particular, since it has a two-step eccentricity configuration with two eccentricity amounts, the first eccentricity amount and the second eccentricity amount, the difference between the revolution speed and the rotation speed can be set finely, resulting in high polishing. Quality is also easily obtained.

In this embodiment, the eccentric direction of the first eccentric support surface 20 with respect to the rotation center of the intermediate shaft 14 and the eccentric direction of the second eccentric support surface 21 with respect to the first eccentric support surface 20 are the same. It may be in a different direction or in the opposite direction.

Also, the external gear 34 is a component that forms a gear mechanism together with the internal gear 24 to which the polishing pad 3 is attached and rotates. may be used. An example using a planetary gear mechanism is shown in FIG. This planetary gear mechanism is a so-called planetary type. Three planetary gears 50 are meshed with the internal gear 24 and revolve around the sun gear 51 while rotating. The sun gear 51 rotates integrally with the intermediate shaft 14 and rotates around the center of the first eccentric support surface 20 . A polishing pad 3 (not shown) is attached to a planetary carrier 52 that revolves around the sun gear 51 together with the three planetary gears 50 . Accordingly, the polishing pad 3 rotates around the sun gear 51 together with the planetary carrier 52 . That is, the polishing pad 3 rotates around the center of the first eccentric support surface 20 as the center of rotation. Since the internal gear 24 is eccentric with respect to the intermediate shaft 14 by the first eccentricity, the polishing pad 3 revolves with the revolution radius of the first eccentricity. In this case, the planetary carrier 52 constitutes a gear mechanism together with the internal gear 24 and serves as a rotating component. Even if the planetary gear mechanism is used in this way, the revolution and rotation of the polishing pad 3 can be separated from each other.

REFERENCE SIGNS LIST 1 head section 2 grip section 3 polishing pad 4 main housing 5a upper gear case (fixing member)
5b lower gear case (fixed member)
6 dust cover 7 motor (driving source)
8 motor shaft 9 bearing (upper end of motor shaft)
10 trigger switch 11 speed controller 12 bearing (lower part of motor shaft)
13 reduction gear 14 intermediate shaft (drive shaft)
15 bearing (upper end of intermediate shaft)
16 bearing (intermediate part of the intermediate shaft)
17 large-diameter tubular portion 20 first eccentric support surface 21 second eccentric support surface 22 bearing (outer ring member)
23 Outer ring member 24 Internal gear 25 Eccentric pin (anti-rotation mechanism)
26 bearing (top of eccentric pin)
27 bearing (bottom of eccentric pin)
30 balance weight 31 bearing (spindle shaft)
32 spindle shaft 33 bearing (upper end of spindle shaft)
34 External gear 40 Support plate 41 Dustproof sheet 50 Planetary gear 51 Sun gear 52 Planetary carrier

Claims (3)

a driving source;
a housing;
a first support surface rotationally driven about a predetermined rotation center by the drive source and rotatably supported by the housing and eccentric with respect to the rotation center by a first eccentricity; a second support surface eccentric by a second eccentricity amount ;
an outer ring member rotatably supported by the first support surface via a first bearing and including an internal gear;
a detent mechanism disposed between the housing and the outer ring member to prevent the rotation of the outer ring member and allow the revolution of the outer ring member;
a structural member including an external gear that is rotatably supported by the second support surface via a second bearing and meshes with the internal gear;
a polishing pad that is attached to the component and that revolves and rotates by rotation of the drive shaft;
Equipped with a polisher. 2. The polisher according to claim 1, wherein a gear mechanism including said internal gear and said external gear is configured as a hypocycloid mechanism. The first support surface is a part of the outer peripheral surface of the drive shaft,
the second support surface is a part of the inner peripheral surface of the drive shaft;
3. The polisher according to claim 1, wherein said second support surface is positioned closer to said polishing pad than said first support surface.

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