JP2001328053A - Sanding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably hold the sealing performance of a housing inside. SOLUTION: A beating retainer 28 into which a connection shaft 16 is loosely inserted is locked to the lower part of a bottom housing 5 by a screw, while an iron plate 32 larger than the loose insertion hole 31 for the connecting shaft 16 in the bearing retainer 28 is externally fitted around the bearing retainer 28 with no contact, and a ring sponge 33 stuck on the bottom portion 30 of the bearing retainer 28 and sealing an opening 24 by slide-contacted with the bottom face of the iron plate 32 in an eccentric motion of the connecting shaft 16 is provided between the bearing retainer 28 and the iron plate 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a connecting shaft which eccentrically moves from an opening formed below a main body housing.
The present invention relates to a sander having a base connected to the connection shaft.

[0002]

2. Description of the Related Art A conventional sander is shown in FIG. Thunder 40
A spindle 43 that rotates in mesh with an output shaft 42 of the motor is supported downward in the main body housing 41, and a connecting shaft 44 formed below the spindle 43 projects from an opening 45 below the main body housing 41. The base 46 is connected to the tip. A sun gear 48 is externally mounted on the connection shaft 44 via ball bearings 47, 47, while an internal gear 49 into which the sun gear 48 is loosely inserted and meshes is provided in the opening 45 via the ball bearing 50. Supported. Therefore, when the spindle 43 rotates with the driving of the motor, the connecting shaft 44 eccentrically moves, and the sun gear 48 eccentrically moving integrally with the connecting shaft 44 meshes with the inner periphery of the internal gear 49, so that the connecting shaft 44 rotates by itself. Then, the base 46 and the polishing disk 51 integrally connected to the lower surface of the base 46 are caused to perform orbital motion (rotational motion + eccentric motion).

[0005] Reference numeral 52 denotes a plate-shaped bearing retainer which is screwed to the main body housing 41 so as to close the opening 45 and positions the ball bearing 50. Is connected to the upper end of a cylindrical seal member 54. This sealing member 54
The dust collection path 5 formed around the opening 45 below the main body housing 41 with its lower end in contact with the upper surface of the base 46.
5 is sealed with the inside of the bearing retainer 52, and the dust collecting holes 56 and 5 formed in the base 46 and the polishing disk 51 are sealed.
6 prevents dust from being guided to the dust collection path 55 from entering the inside of the main body housing 41.

[0004]

The above-mentioned sealing member 54
The contact state of the seal member 54 with the base 46 varies depending on the state of the upper surface of the base 46, the dimensional tolerance, and the like, and if the contact force is too strong, the abrasion is promoted and the durability is reduced even if the sealing property can be secured. On the other hand, if the contact force is too weak, the sealing effect is reduced although the durability is advantageous. On the other hand, since the base 46 requires a flat surface 57 for slidingly contacting the seal member 54, the shape of the base 46 is restricted.

Accordingly, an object of the present invention is to provide a sander which can always maintain good sealing performance and durability irrespective of the state of the base and dimensional tolerance.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, the opening is closed below the main body housing in a range where the connecting shaft is loosely inserted and does not interfere with the eccentric movement of the connecting shaft. A possible first closing member is provided orthogonal to the connecting shaft, and a second closing member larger than the play hole of the connecting shaft in the first closing member is provided on the connecting shaft in a non-contact manner with the first closing member. The first closing member and the second closing member are fixed to one of the opposing surfaces of the first closing member and the second closing member between the first closing member and the second closing member. A seal member is provided, which is capable of sealing the opening by sliding contact with the surface. According to the second aspect of the present invention, in addition to the object of the first aspect, in order to easily obtain an appropriate seal member, the seal member is a ring-shaped sponge.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial longitudinal sectional view of a random orbit sander (hereinafter referred to as “sander”). A main housing 2 of the sander 1 is made of a metal obtained by assembling an upper housing 4 and a lower housing 5 which are vertically divided. And a second housing 6 made of synthetic resin and attached from the front surface of the first housing 3 (the left side in FIG. 1 will be described as the front). In the first housing 3, an output shaft 7 of a motor built in a motor housing (not shown) behind the main body housing 2 protrudes, and a first bevel gear 8 is integrally fixed to a tip end. The first bevel gear 8 has a ball bearing 9,
The shaft 10 meshes with a second bevel gear 12 integral with a spindle 11 that is vertically supported by the shaft 10 so that the rotation of the output shaft 7 can be transmitted to the spindle 11.

An eccentric shaft 13 eccentric from the center of rotation is projected from the lower end of the spindle 11, and a sleeve 14 is integrally fitted to the eccentric shaft 13 via ball bearings 15, 15 on the sleeve 14. The connecting shaft 16 is coaxially provided. A base 18 is orthogonally connected to a lower end of the connecting shaft 16 by a bolt 17, and a polishing disk 19 is fixed to a lower surface of the base 18. 20, 21
Is a balance weight integrally connected to the upper and lower sides of the spindle 11. Also, teeth 23,
The sun gear 22 surrounding the sun gear 22 is integrally fitted, while an internal gear 25 having a larger diameter than the sun gear 22 has a ball bearing 26 in an opening 24 below the lower housing 5 further on the outer periphery of the sun gear 22. Through the spindle 11
The teeth 23 of the sun gear 22 mesh with the teeth 27 formed on the inner periphery of the internal gear 25. The lower housing 5 is provided with a stopper pin which can be protruded and retracted by an operation knob (not shown).
The rotation of the internal gear 25 can be arbitrarily locked and released by engaging and disengaging the outer periphery of the internal gear 25.

On the other hand, a flange 29 on the outer periphery of a dish-shaped bearing retainer 28 is screwed into the opening 24 of the lower housing 5 as a first closing member.
Are positioned. The connecting shaft 16 is connected to the bottom 30 of the bearing retainer 28.
The base 18 is connected by loosely inserting a play insertion hole 31 (drilled so as not to interfere with the orbital movement of the connection shaft 16) formed at the center of the base. A circular iron plate 32 serving as a second closing member is provided at a position above the bottom 30 of the bearing retainer 28 on the connection shaft 16.
Is fitted outside at right angles. As shown in FIG. 2, the iron plate 32 is formed to have a larger diameter than the play insertion hole 31 of the bearing retainer 28, and overlaps the bottom 30 of the bearing retainer 28 in the axial direction of the connection shaft 16 without contact. A sponge 33 as a seal member is adhered on the bottom 30 of the bearing retainer 28. This sponge 33
The inner circumference circle has the same diameter as the play insertion hole 31, and the outer circumference circle has a rectangular cross-sectional shape having the same diameter as the bottom portion 30.
1, and the upper surface thereof is brought into contact with the lower surface of the iron plate 32 which is the facing surface of the bottom portion 30, so that the sliding contact with the iron plate 32 can always be maintained regardless of the orbital movement of the connecting shaft 16. ing.

On the other hand, the base 18 and the polishing disk 19 are provided with dust collecting holes 34, 34. It communicates with the dust path 35. This dust collection path 35
By communicating with a dust collecting tube 36 protruding from the lower housing 5 and connecting a dust collector or the like to the dust collecting tube 36, dust can be collected from the dust collecting holes 3.
4 and 34, and can be guided to the inside of the dust collection path 35 and discharged to the outside of the lower housing 5 through the dust collection tube 36.
A partition plate 37 having a lower end close to the upper surface of the base 18 is provided around the outer periphery of the dust collection path 35 in the lower housing 5, thereby dividing the dust collection path 35 from the outside of the lower housing 5. Therefore, on the inner side of the lower housing 5, the dust collection path 35 is partitioned by the bearing retainer 28 that closes the opening 24, the iron plate 32, and the sponge 33.
Is partitioned by a partition plate 37 on the outside side of.

When the motor (not shown) is driven in a state where the rotation of the internal gear 25 is locked, the sander 1 having the above-described configuration allows the first bevel gear 8 and the second bevel gear 12 to rotate with the rotation of the output shaft 7. The engagement causes the spindle 11 to rotate, and the eccentric shaft 13 at the lower end thereof and the eccentric shaft 13
Is revolved, i.e., eccentrically, with the connecting shaft 16 that supports the shaft, and the base 18 and the polishing disk 19 at the lower end of the connecting shaft 16 are eccentrically moved. Here, the teeth 23 of the sun gear 22 that eccentrically move with the connecting shaft 16 mesh with the teeth 27 of the internal gear 25 that does not rotate. Is generated, causing the base 18 and the polishing disk 19 to rotate similarly. Therefore, the base 18 and the polishing disk 19 perform the orbital motion of the rotational motion and the eccentric motion,
An operator can support the sander 1 and press the polishing disk 19 against the work to perform polishing. During this orbital movement, the iron plate 32 integral with the connecting shaft 16 also performs the orbital movement at the same time, but the lower surface thereof is always in sliding contact with the sponge 33 on the bearing retainer 28 fixed to the lower housing 5, so that the opening 24 is preferably formed. It is sealed, and there is no possibility that dust generated during the polishing operation enters the inside of the lower housing 5 when passing through the dust collection passage 35 from the dust collection holes 34.

As described above, according to the above embodiment, the seal on the inner side of the lower housing 5 is formed by the bearing retainer 28 on the lower housing 5 side, the iron plate 32 on the connecting shaft 16 side, and the sponge 33 interposed therebetween. By doing so, it is possible to seal the opening 24 irrespective of the base 18 side, and the sealing performance is not varied or abraded due to dimensional tolerances, the state of the upper surface of the base 18 and the like, and a stable sealing is achieved. Properties and durability can be obtained. Further, since the base 18 does not require a flat surface or the like for slidingly contacting the seal member, the shape of the base 18 is not restricted. In addition, since the sealing member is merely sandwiched in a sandwich shape and a large sealing area can be secured, it is sufficient to simply use a sponge 33 made of a ring-shaped and inexpensive material as the sealing member. An appropriate seal member can be easily obtained without using a seal member made of a suitable material.

In the above embodiment, the iron plate 32 is located above the bottom 30 of the bearing retainer 28. However, the reverse is also possible, and the sponge 33 is bonded not to the bottom 30 but to the iron plate 32. No problem. In addition to the sponge 33, other materials such as rubber and felt can be used as the seal member. Furthermore, the shape of the sealing member such as a sponge is not limited to the above-described embodiment as long as it can be sealed between the first closing member and the second closing member, but the first closing member or the second closing member as in the above-described embodiment. If the sliding contact surface is continuously formed in the radial direction, the first
This is a preferable mode without obstructing the orbital movement of the closing member or the second closing member.

[0014]

According to the first aspect of the present invention, the opening of the main body housing can be sealed by using the first closing member, the second closing member, and the sealing member, thereby irrespective of the base side. The opening can be sealed, and the sealing property does not vary or wear occurs due to the dimensional tolerance, the state of the upper surface of the base, and the like, and stable sealing property and durability can be obtained. In addition, since the base does not require a flat surface or the like for slidingly contacting the seal member, the shape of the base is not restricted. Furthermore, since the sealing member is merely sandwiched in a sandwich shape and a large sealing area can be secured, there is no need to use a conventional special sleeve-shaped sealing member of an expensive material, and a simple shape and inexpensive sealing member can be used. Is enough. According to the second aspect of the present invention, in addition to the effect of the first aspect, by using a ring-shaped sponge for the seal member, an inexpensive and appropriate seal member can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a sander.

FIG. 2 is an explanatory view of the bearing retainer as viewed from above from the lower surface side.

FIG. 3 is a partial vertical sectional view of a conventional sander.

[Explanation of symbols]

1. Sander, 2. Body housing, 3. First housing, 4. Upper housing, 5. Lower housing, 1
1 ··· spindle, 13 · · · eccentric shaft, 16 · · · connecting shaft,
18 ・ ・ base 、 19 ・ ・ polishing disc 、 25 ・ ・ internal gear 、 28 ・ bearing retainer 、 32 ・ ・
Iron plate, 33 ... sponge, 35 ... dust collection path.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoshi Ninagawa 3-11-8 Sumiyoshi-cho, Anjo-shi, Aichi F-term in Makita Co., Ltd. (reference) 3C034 AA08 AA15 BB02 BB26 BB87 3C058 AA02 AC05 CB06 3J043 AA17 CA20 CB13 DA02 DA05

Claims (2)

[Claims] 1. A sander having a connecting shaft projecting eccentrically from an opening formed below a main body housing and connecting a base to the connecting shaft, wherein the connecting shaft is provided below the main body housing. A first closing member capable of closing the opening in a range that does not interfere with the eccentric movement of the connecting shaft by loose insertion is provided orthogonal to the connecting shaft, while the connecting shaft is provided with the first closing member of the connecting shaft in the first closing member. A second closing member larger than the play insertion hole is provided in a non-contact manner with the first closing member and perpendicular to the connection shaft, and the first closing member and the second closing member are provided between the first closing member and the second closing member. Second
A sander fixed to one of the opposing surfaces with a closing member, and provided with a sealing member capable of sealing the opening by slidingly contacting the other opposing surface during the eccentric movement. 2. The sander according to claim 1, wherein the sealing member is a ring-shaped sponge.