JP2007152526A - Grinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain favorable operability of a lock member by preventing entering of powder dust. <P>SOLUTION: A gear housing 6 is provided with a blowout port 27 communicating the inside of the gear housing 6 with a storing part 15 of the lock member 16, the lower end of which is located on the same plane as the base of the storing part 15, and some of cooling air fed into the gear housing 6 by a fan 23 is blown out forward to be orthogonal to the lock member 16 along the base of the storing part 15. Thus, the cooling air is blown out to prevent powder dust from entering a clearance between the storing part 15 and a cap 19 and a space between a pin 17 and a holding part 20, so that the operability of the lock member 16 can be maintained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a grinder in which a disc-shaped grindstone is mounted on a spindle that protrudes downward from a housing, and a grinding operation can be performed by rotating the disc-shaped grindstone.

A grinder is a material to be polished by a disc-shaped grindstone that is supported by a spindle mounted in a vertical direction in a housing and protrudes downward from the housing. The polishing work is possible. Further, a gear such as a bevel gear, which is rotationally transmitted from the output shaft of the motor that protrudes into the housing, is externally mounted on the spindle so as to be integrally rotatable by a coupling means such as a key coupling or a two-surface width fitting.
On the other hand, the grinder is provided with a lock member capable of arbitrarily locking the rotation of the spindle in the housing in order to facilitate attachment and detachment of the disc-shaped grindstone with respect to the spindle. For example, as shown in Patent Document 1, the lock member is a shaft body that can be projected and retracted into the housing above the housing and is biased to the protruding position, and is pushed onto the upper surface of the bevel gear by being pushed into the housing. The lower end is fitted into the provided recess, and the rotation of the spindle is locked via the bevel gear.

JP 2001-9757 A

  In the grinder, dust generated by the polishing operation may enter the lock member installation site in the housing. For this reason, a large resistance occurs when the lock member is pushed in, or the return of the pushed lock member is delayed, and the operability of the lock member is deteriorated. In particular, if the switch of the motor is turned on without noticing that the lock member pushed in by dust does not return completely (the bevel gear is locked), the lock member or the like may be damaged.

  Therefore, an object of the present invention is to provide a grinder that can effectively prevent dust from entering the site where the lock member is installed and can maintain a suitable operability of the lock member.

In order to achieve the above object, the invention described in claim 1 is a grinder that allows the cooling air of the motor to pass through the housing by the rotation of the fan provided on the output shaft of the motor. A guiding means for guiding a part of the air and blowing the air toward the installation site of the lock member outside the housing is provided.
According to the second aspect of the present invention, in addition to the object of the first aspect, in order to form the guiding means more easily and effectively, the guiding means communicates with the cooling air flow path and is formed on the outer surface of the housing. A part of the cooling air is blown out in a crossing manner with the lock member.

According to invention of Claim 1, the penetration | invasion of the dust to the installation site | part of a lock member is prevented effectively. Therefore, suitable operability of the lock member can be maintained over a long period of time, and the risk of damage to the lock member due to dust intrusion is eliminated. Further, since the cooling air for the motor is rationally used, the cost increase associated with the use of the guiding means can be minimized.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the guiding means can be formed with a simple configuration in which the air outlet is provided, and the cooling air can be more effectively prevented from entering dust. Speech balloons are also possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an example of a grinder, FIG. 2 is a plan view, and the grinder 1 is output in front of the motor housing 2 housing the commutator motor 3 (left side in FIG. 1). A gear housing 6 as a housing of the present invention is assembled via a bearing plate 5 that supports the shaft 4 and a rear cover 7 is assembled to the rear. A slide button 8 is provided on the side surface of the motor housing 2 and turns on / off a switch provided in the rear cover 7 by a slide operation.
In the gear housing 6, an output shaft 4 protrudes, and a spindle 9 is pivotally supported in the vertical direction in front of the output shaft 4, and a first bevel gear 10 that is integrally packaged at the tip of the output shaft 4; The rotation of the output shaft 4 can be transmitted to the spindle 9 by meshing with the second bevel gear 11 integrally mounted on the spindle 9. The lower end of the spindle 9 protrudes downward from the gear housing 6, and is screwed into an inner flange 12 that is integrally coupled to the spindle 9 by fitting with two face widths, and a screw portion provided at the lower end of the spindle 9. A disk-shaped grindstone 14 can be mounted orthogonally by the outer flange 13.

  Further, a planar circular accommodating portion 15 is recessed on the upper surface of the gear housing 6, and a lock member 16 is provided in the accommodating portion 15. The lock member 16 includes a pin 17 whose lower end is a large-diameter portion 18 and a circular cap 19 that is fitted to the upper end of the pin 17. The pin 17 is coaxially formed on the bottom surface of the housing portion 15. A large-diameter portion 18 of the pin 17 is normally in contact with the lower end of the holding portion 20 by a coil spring 21 which is loosely inserted into the cylindrical holding portion 20 and is sheathed between the bottom surface of the housing portion 15 and the cap 19. Is biased to the upper limit position. On the other hand, on the upper surface of the second bevel gear 11, recesses 22, 22... Into which the large-diameter portion 18 of the pin 17 can be fitted are formed on a concentric circle at three equal intervals. Therefore, when the lock member 16 is pushed downward against the bias of the coil spring 21 with any of the recesses 22 positioned directly below, the large diameter portion 18 is fitted into the recess 22 and the second bevel gear 11 rotates. And the rotation of the spindle 9 integrated therewith can be locked.

On the other hand, a fan 23 is integrally fitted to the rear portion of the bearing plate 5 in the output shaft 4, and a plurality of vent holes 24, 24... Are formed at the outer periphery of the fan 23 in the bearing plate 5. . A baffle plate 25 is sandwiched and fixed between the motor housing 2 and the bearing plate 5 and covers the rear outer periphery of the fan 23.
Further, a plurality of exhaust ports 26, 26,... Are formed above and below the gear housing 6, respectively, while a plurality of intake ports (not shown) are formed on the rear surface of the rear cover 7. Therefore, when the fan 23 rotates with the rotation of the output shaft 4, outside air is sucked from the intake port, passes through the commutator motor 3, reaches the inside of the gear housing 6 from the ventilation port 24 via the fan 23, and is exhausted. A flow path for cooling air discharged from 26 to the outside is formed. The commutator motor 3 is cooled by the cooling air.

  The gear housing 6 communicates the inside of the gear housing 6 in which the cooling air flow path is formed with the housing portion 15 of the lock member 16, and the lower end is located on the same plane as the bottom surface of the housing portion 15. A part of the cooling air fed into the gear housing 6 by the fan 23 is formed in the shape of the air outlet 27 as a means and intersects with the lock member 16 along the bottom surface of the accommodating portion 15 (in this case, orthogonal). It is possible to blow out forward. The cap 19 is formed in such a size that a gap through which air can pass is left between the cap 19 and the inner surface of the housing portion 15.

In the grinder 1 configured as described above, when the commutator motor 3 is driven by operating the slide button 8, the output shaft 4 rotates and the spindle 9 rotates via the first and second bevel gears 10 and 11. To do. Therefore, the disc-shaped grindstone 14 also rotates integrally with the spindle 9 to polish the material to be polished.
The fan 23 is rotated by the rotation of the output shaft 4, and the cooling air taken in from the intake port of the rear cover 7 as described above is allowed to pass through the motor housing 2 and the gear housing 6 from the exhaust port 26 and the air outlet 27. Discharge. At this time, the cooling air discharged from the air outlet 27 is blown orthogonally to the pins 17 of the rod member 16 along the bottom surface of the housing portion 15, and then passes through the gap between the housing portion 15 and the cap 19. It will be discharged to the outside. By blowing out the cooling air, dust is prevented from entering between the gap between the accommodating portion 15 and the cap 19 and between the pin 17 and the holding portion 20.

  When the disk-shaped grindstone 14 is attached or detached, the rotation of the spindle 9 is locked by pushing the lock member 16 downward and fitting the large diameter portion 18 at the lower end into the recess 22 of the second bevel gear 11. . Therefore, it is possible to exchange the disc-shaped grindstone 14 by loosening the outer flange 13 screwed to the lower end of the spindle 9. Similarly, when the rotation of the spindle 9 is locked by the lock member 16 at the time of mounting, the outer flange 13 can be screwed. At this time, since the intrusion of dust into the accommodating portion 15 side is prevented by blowing out the cooling air as described above, the lock member 16 can be pushed in smoothly, and when the pushing is released, the coil spring 21 By urging, the lock member 16 surely returns to the upper limit position.

Thus, according to the grinder 1 of the said form, the guidance means (air outlet 27) which guides a part of cooling air to the gear housing 6, and blows it out toward the installation site | part of the lock member 16 on the outer side of the gear housing 6. ) Is effectively prevented from entering dust into the installation site of the lock member 16. Therefore, suitable operability of the lock member 16 can be maintained over a long period of time, and the risk of damage to the lock member 16 due to intrusion of dust is also eliminated. Further, since the cooling air of the commutator motor 3 is reasonably used, the cost increase associated with the use of the induction means can be minimized.
In particular, the air outlet 27 communicates with the cooling air flow path and is a blower outlet 27 that blows a part of the cooling air along the outer surface of the gear housing 6 so as to intersect the lock member 16. The guiding means can be formed with a simple configuration, and cooling air can be blown out more effectively to prevent dust from entering.

Note that the number of outlets is not limited to one, and can be changed as appropriate, for example, by providing a plurality of locations so as to surround the lock member, or by providing air on the bottom surface of the accommodating portion.
Further, the guiding means is not limited to the above-mentioned air outlet, and depending on the positional relationship between the cooling air flow path and the locking member, a duct-shaped passage may be formed inside or outside the housing to A structure for guiding cooling air to the installation site is also conceivable. Of course, a plurality of different types of guiding means may be provided.
Furthermore, the form of the locking member is not limited to the above form, and the present invention can be adopted even if the holding member or the cap is not provided.
In addition, the gear to be locked is not limited to the bevel gear, and a grinder using another gear such as a spiral bevel gear or a helical gear may be used.

It is a longitudinal cross-sectional view of a grinder. It is a top view of a grinder.

Explanation of symbols

1. ・ Grinder, 2 ・ ・ Motor housing, 3 ・ ・ Commutator motor, 4 ・ ・ Output shaft, 6 ・ ・ Gear housing, 9 ・ Spindle, 11 ・ ・ Second bevel gear, 14 ・ ・ Disc grinding wheel 15 ・· Housing part, 16 ·· Lock member, 17 ·· Pin, 19 ·· Cap, 20 ·· Holding part, 21 ·· Coil spring, 22 ·· Recess, 23 ·· Fan, 26 ·· Exhaust port, 27 ·· Air outlet.

Claims (2)

In a housing, a spindle with a gear that is rotated and transmitted from the output shaft of the motor is pivotally supported in the vertical direction, and a disc-shaped grindstone can be attached to the lower end of the spindle that projects downward from the housing. The housing is provided with a lock member capable of locking the rotation of the gear and the spindle by being engaged with the gear by a pushing operation into the housing, and the housing provided by the rotation of the fan provided on the output shaft of the motor. A grinder for allowing the cooling air of the motor to pass therethrough,
A grinder provided with guiding means for guiding a part of the cooling air to the housing and blowing out the air toward an installation site of the lock member outside the housing. The grinder according to claim 1, wherein the guide means is a blower outlet that communicates with a cooling air flow path and blows out a part of the cooling air along the outer surface of the housing in a crossing manner with the lock member.

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