JP6687397B2 - Grinding machine - Google Patents

Description

  The present invention relates to a grinding device. More specifically, the present invention relates to a grinding device that has both operability and dust scattering prevention properties.

  2. Description of the Related Art As a grinding device for grinding the surface of a work material, there is known one having a dust collecting cover for preventing dust scattering.

  For example, in Japanese Unexamined Patent Application Publication No. 2012-171064 (Patent Document 1), an annular peripheral wall portion that is arranged around a grinding blade that is rotationally driven to grind a surface to be processed, and one end facing the surface to be processed is opened, An end wall portion that is located on the other end side of the peripheral wall portion and defines a storage space for accommodating the grinding blade together with the peripheral wall portion, and an end wall portion that is mounted on a power tool that rotationally drives the grinding blade, and is configured in an annular shape. A sealing member mounted on the one end side of the peripheral wall portion and abutting the surface to be processed, the sealing member being directed from the one end side of the peripheral wall portion toward the other end side of the peripheral wall portion. There is disclosed a dust collecting cover for grinding, which has guide means for generating an air flow. As the seal member, a cloth ring made of a belt-shaped cloth made of felt and configured in an annular shape is used.

  Further, Japanese Patent Laid-Open No. 2012-176474 (Patent Document 2) discloses a portable disk grinder in which a disk-shaped tip tool can be attached to a spindle, and a peripheral wall covering the entire circumference of the tip tool and a rear surface side. A cover body formed in a cup shape having an opening at one end, a mounting portion provided on the ceiling wall and fixed to a boss portion of the disc grinder from which the spindle protrudes, and the ceiling wall A stand provided so as to project from the top wall toward the side opposite to the opening, and provided on the upper end of the stand, and arranged on the spindle axis when the mounting portion is fixed to the boss portion. A disk grinder is disclosed which has a handle. In this disc grinder, a skirt (sealing member) is provided at the tip of the peripheral wall, and it is described that the skirt (sealing member) may be formed by using a felt, a brush, a sponge or the like.

JP 2012-171064 A JP2012-176474A

  In both of Patent Document 1 and Patent Document 2 described above, the seal member is provided on the cover via the spring member. By biasing the spring member against the seal member, the seal member is brought into contact with the surface of the work material.

  Here, both the seal members of Patent Document 1 and Patent Document 2 are fixed to a holding member having a convex portion (convex portion 41A in Patent Document 1) and a holding piece (holding piece 35 in Patent Document 2), The convex portion and the holding piece are loosely fitted in a concave portion (concave portion 21a in Patent Document 1) and a retaining groove (retaining groove 32c in Patent Document 2, respectively) provided inside the peripheral wall of the cover. The seal member of Patent Document 1 and Patent Document 2 must be brought into contact with the surface of the work material by being pushed down by the spring member. For this reason, it is essential that the surface of the seal member that is fixed to the holding member should not be fixed to the cover because of its design. This is the reason why the holding member for the seal member is provided in the state of being loosely fitted to the cover as described above.

However, the loose fitting structure as described above is unavoidable for allowing a large amount of air to pass therethrough. Therefore, even if the inside of the cover is continuously sucked, there is no attraction of the cover to the surface of the work material. Therefore, the holding property of the device with respect to the surface of the work material is poor during the grinding work.
That is, when processing a vertical wall surface, an inclined wall surface (in particular, an inclined wall surface having a larger inclination than the vertical wall surface), and a ceiling surface, the operator must continue to support the vertical load due to the weight of the device. . Such a load imposes a heavy burden on the operator. Therefore, the conventional devices cannot be said to be excellent in operability.

  Therefore, in view of the above problems, it is an object of the present invention to provide a grinding device in which the operator does not have to bear the weight of the device to improve the operability.

(1)
The present invention is a grinding device for grinding the surface of a work material. The grinding device of the present invention includes a housing, an output shaft, a grinding blade, a cover, and a suction unit.
The housing houses the drive mechanism. The output shaft is projected from the drive mechanism. The grinding blade is fixed to the output shaft and extends along a plane orthogonal to the output shaft. The cover includes a peripheral wall portion and a suction port. The peripheral wall portion opens on the side of the grinding blade opposite to the side that should face the surface of the work material, and covers the entire circumference of the grinding blade. The suction unit is connected to the suction port.
Further, the weight X (kgf) of the grinding device (hereinafter, referred to as own weight X) and the gravity generated when the suction unit is operated in a state where the open end of the cover is in contact with the surface of the work material. Is expressed by the following formula (I):
Y / X> 1 (I)
Meet

  Thus, since the cover surrounding the grinding blade by the peripheral wall is connected to the suction unit via the suction port, by operating the suction unit with the opening end of the cover in contact with the work surface, The inside of the cover is depressurized and the open end is sucked to the work surface. Even when the work surface is not horizontal (including the case where the work surface is a top surface that makes an angle of 180 ° with the horizontal plane), the suction pressure (negative pressure) inside the cover causes a force in the direction opposite to gravity. Since Y acts so as to be larger than the self-weight X of the grinding device, the grinding device can be attracted to the work surface which is not a horizontal surface during the work. Therefore, it is possible to eliminate the burden of the operator supporting the own weight X of the grinding device.

  The weight X does not include the weight of the suction unit and the weight of the exhaust hose connecting the suction unit and the suction port.

(2)
In the grinding device of the above (1), the output shaft can reciprocate in the protruding direction from the drive mechanism, and may include a film body. The film body seals the side of the peripheral wall opposite to the side that should face the surface of the work material, and has a flexible part that is linked to the output shaft and a fixed part that is fixed to the peripheral wall. including.

  In this case, by operating the suction unit with the opening end of the cover in contact with the work surface, the inside of the cover is depressurized and the opening end is sucked into the work surface, and the suction pressure (negative pressure) inside the cover is reduced. ) Pulls in the flexible portion of the film body fixed to the cover toward the surface to be cut, so that the output shaft interlocking with the flexible portion and the grinding blade fixed thereto are also pulled in similarly. Therefore, by operating the suction unit with the open end of the cover in contact with the work surface, the grinding blade can be easily applied to the work surface. Therefore, as long as the suction unit is operating, not only is there no burden to support the own weight X, but it is also possible to easily continue to press the device against the work surface with the grinding blade touching the work surface. Therefore, stable machining and finishing can be performed regardless of the skill of the operator.

(3)
In the grinding device of the above (2), the force Y (kgf) in the direction opposite to gravity, the coefficient of static friction μ at the open end of the cover with respect to the surface of the work material, and the cover are brought into contact with the surface of the work material. The following formula (II) that is satisfied by the actual suction force N (kgf) that the cover attracts to the surface of the work material when the suction unit is operated in this state:
Y = μN (II)
In relation to the actual suction force N (kgf), the inner peripheral area Sc (cm ² ) of the opening end of the cover, the inner peripheral area Sd (cm ² ) of the flexible portion, and the vacuum degree P (kPa of the suction unit). ) And the relationship between the following formula (III):
N = P (Sc-Sd) (III)
May be satisfied.

  In this way, the inner peripheral area Sc of the opening end of the cover and the inner peripheral area Sd of the flexible portion are designed so as to satisfy the above-mentioned expressions (I), (II), and (III), and the opening end of the cover is designed. By selecting a material having a static friction coefficient μ and setting the vacuum degree P by the suction unit, as long as the suction unit is operating, not only is there no burden to support the own weight X, but also the grinding blade is It is also possible to easily continue pressing the device against the work surface while touching the work surface.

  When the surface to be cut is a top surface that makes an angle of 180 ° with the horizontal plane, friction does not work when the grinding device is stationary, so the static friction coefficient μ can be regarded as 1.

(4)
The grinding apparatus of (2) above may include a blade amount adjusting unit that adjusts the position of the grinding blade in the protruding direction of the output shaft. The blade amount adjusting unit has a pressing surface and includes a stretchable portion. The pressing surface is provided on the side of the housing facing the work surface so as to be interlocked with the output shaft. The expansion / contraction portion is provided between the pressing surface and the cover and expands / contracts in the protruding direction of the output shaft.

  In this case, when the grinding blade fixed to the output shaft is pulled toward the work surface by the operation of the suction unit, the pressing surface is also pushed down toward the work surface in conjunction with the output shaft fixing the grinding blade. . As a result, the stretchable portion provided between the pressing surface and the cover stretches. At the same time, a reaction force due to the expansion and contraction force is generated toward the pressing surface, and a force that pulls the grinding blade fixed to the output shaft interlocking with the pressing surface back to the side opposite to the work surface acts. As a result, even if the pulling of the grinding blade to the work surface by the operation of the suction unit alone pushes the grinding blade against the work surface with an excessive force, it is possible to perform a proper pulling back by the above reaction force. The pressing force can be appropriately adjusted by the action.

(5)
In the grinding device of the above (4), the force Y (kgf) in the direction opposite to gravity, the coefficient of static friction μ at the open end of the cover with respect to the surface of the work material, and the cover are brought into contact with the surface of the work material. The following formula (II) that is satisfied by the actual suction force N (kgf) that the cover attracts to the surface of the work material when the suction unit is operated in this state:
Y = μN (II)
In relation to the actual suction force N (kgf), the inner peripheral area Sc (cm ² ) of the opening end of the cover, the inner peripheral area Sd (cm ² ) of the flexible portion, and the vacuum degree P (kPa) by the suction unit. , And the reaction force F (kgf) with which the expandable part urges the pressing surface when the suction part is operated while the cover is in contact with the surface of the work material, the following formula (IV ):
N = P (Sc-Sd) + F (IV)
May be satisfied.

  In this way, the inner peripheral area Sc of the opening end of the cover and the inner peripheral area Sd of the flexible portion are designed so as to satisfy the relationships of the above formulas (I), (II), and (IV). By selecting a material having a static friction coefficient μ and a stretchable portion having a reaction force F and a stretchable portion having a stroke, and setting the vacuum degree P by the suction unit, the grinding blade is covered by the operation of the suction unit. Even if the pulling into the cutting surface alone pushes the grinding blade against the surface to be cut with an excessive force, the pressing force can be appropriately adjusted by the action of appropriate pulling back by the reaction force.

  If the surface to be cut is a top surface that makes an angle of 180 ° with respect to the horizontal plane, friction with respect to its own weight does not work when the grinding device is stationary without being loaded in the direction of the top surface. The static friction coefficient μ in this state is considered to be 1.

(6)
In the grinding device of the above (5), the reaction force F of the expandable portion may be 0 kgf or more and 35.2 kgf or less.

  In this case, it is easy to properly adjust the pressing force of the grinding blade against the work surface.

(7)
In the grinding device according to any one of (3), (5) and (6), the coefficient of static friction μ may be 0.21 or more.

  This makes it easier to attract the device to the grinding surface when the surface to be machined is vertical and inclined.

(8)
In the grinding device according to any one of (3) and (5) to (7), the degree of vacuum P by the suction unit may be 1 kPa or more and 90 kPa or less.

  This makes it easier to attract the device to the grinding surface.

(9)
The grinding device according to any one of (1) to (8) above is used when the suction unit is operated with the weight X (kgf) of the grinding device and the opening end of the cover being in contact with the surface of the work material. The relationship between the generated force Y (kgf) in the direction opposite to gravity and the following formula (V):
Y / X <5 (V)
May be satisfied.

  This makes it easy to move the device along the grinding surface while adsorbing it to the grinding surface.

(10)
The grinding device according to any one of (1) to (9) may include a breathable sliding contact member having compression elasticity, which is fixed to the entire circumference of the opening end of the cover.

In this case, since the breathable sliding contact member is fixed to the entire circumference of the opening end of the cover, the inside of the cover is kept in contact with the surface of the work material through the breathable sliding contact member. Can be efficiently depressurized by the suction unit.
In addition, the breathable sliding contact member maintains breathability even when compressed by the suction pressure inside the cover, so even if the inside of the cover is sucked, an appropriate space for communicating the inside and outside of the cover is secured. can do. Therefore, while decompressing the inside of the cover, it is possible to suppress dust scattering between the surface of the work material and the cover by sucking an appropriate small amount of outside air from the gap.
Due to the slidability, the breathable sliding contact member can be easily moved against the suction force while being adsorbed on the surface of the work material and keeping the dust scattering suppressed. it can.
Further, since the breathable sliding contact member has compressive elasticity, it has good contact properties with the surface of the work material and can easily suppress scattering of dust.

  Note that the breathable sliding contact member is fixed to the entire circumference of the opening end of the cover means that the breathable sliding contact member is positioned relative to the fixed surface of the breathable sliding contact member and the opening end of the cover. It means that the relationship is established so that it does not change.

(11)
In the grinding device of (10) above, the coefficient of static friction of the breathable sliding contact member with respect to the surface of the work material may be 0.3 or less.

  As a result, it is possible to reduce the burden on the operator when moving the grinding device from the state where the grinding device is adsorbed on the surface of the work material in a stationary state.

(12)
In the grinding device described in (1) to (11) above, the cover may include a pressure regulating valve.

  Accordingly, if the suction pressure (negative pressure) in the cover by the suction unit is excessive without the pressure regulating valve, an appropriate amount of air can be supplied into the cover to adjust the suction pressure.

It is an appearance perspective view of a grinding device of a 1st embodiment. FIG. 2 is a schematic cross-sectional view of the grinding device of FIG. 1 taken along a plane including line II-II. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 2 is a schematic cutaway view (when not in use) of the grinding device of FIG. 1. FIG. 2 is a schematic cutaway view of the grinding device when the grinding device of FIG. 1 is operated and brought into contact with the surface of a work material. FIG. 6 is a schematic cutaway view of the grinding device of FIG. 1 when finely adjusting the angle of the grinding blade from the state of FIG. 5. It is a fragmentary sectional view of a grinding device which is an example of a 2nd embodiment. It is a fragmentary sectional view of a grinding device which is another example of a 2nd embodiment. It is a partial notch partial sectional view of the grinding device of 3rd Embodiment. It is a fragmentary sectional view of the grinding device of a 4th embodiment. It is a fragmentary sectional view showing after operation of a grinding device of a 4th embodiment. It is a typical fragmentary sectional view of the grinding device of a 5th embodiment. It is a fragmentary sectional view of a grinding device of a 6th embodiment. It is a partial notch partial sectional view of the grinding device of 6th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same elements are designated by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[1. First Embodiment]
[1-1. Basic configuration]
FIG. 1 is an external perspective view of a grinding device according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the grinding device of FIG. 1 taken along a plane including line II-II. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is a schematic cutaway view (when not in use) of the grinding device of FIG. 1. FIG. 5 is a schematic cutaway view of the grinding device when the grinding device of FIG. 1 is operated and brought into contact with the surface of the work material. FIG. 6 is a schematic cutaway view of the grinding apparatus of FIG. 1 when the angle of the grinding blade is finely adjusted from the state of FIG.
In the following description, the upper side of FIG. 2 may be referred to as the upper side of the grinding device, and the lower side of FIG. 2 may be referred to as the lower side of the grinding device (the side on which the work material is located). However, these directions are defined for convenience of description, and do not indicate an absolute direction during use.

  The grinding device 100 shown in FIGS. 1 to 6 should also be called a disc grinder or a keren device, and is a device that grinds a work material such as concrete, metal, or stone with a grinding blade to adjust the surface thereof. The grinding device 100 includes a housing 200, an output shaft 300, a grinding blade 400, a cover 500, a breathable sliding contact member 600, and a suction unit (not shown). Further, the grinding device includes a blade amount adjusting unit 700 and a gripping unit 800.

[1-2. Housing and output shaft]
The housing 200 accommodates a drive mechanism (not shown). The drive mechanism mainly includes a drive source (electric motor in the present embodiment) and a power transmission unit (gear in the present embodiment) that transmits the drive force of the drive source. The housing 200 includes a cylindrical motor case 210 that accommodates an electric motor, and a gear case 220 that is provided at one end of the motor case 210 and that accommodates gears. From the other end of the motor case 210, a power cord 290 connected to a power supply source (not shown) that supplies power to the electric motor extends.

  As shown in FIGS. 2 and 4, a coupling protrusion 221 connected to the gear is provided so as to project from the gear case 220 in a direction intersecting with the extending direction of the motor case 210 (orthogonal in the present embodiment). The connecting projection 221 is connected and fixed to a connecting hole 311 formed at the base end of the output shaft 300, so that the output shaft 300 extends in the protruding direction. As a result, the rotational driving force transmitted from the electric motor through the gear is transmitted to the output shaft 300.

[1-3. Grinding blade]
A grinding blade 400 is provided at the tip portion 390 of the output shaft 300. The grinding blade 400 has a disk shape with an opening at the center, and the output shaft 300 is passed through the opening at the center, so that the direction of a plane orthogonal to the projecting direction of the output shaft 300 (matching the rotation axis O direction). Extend to. The output shaft 300 is equipped with a washer 391 and a nut 392 that sandwich the grinding blade 400 from both upper and lower surfaces. The upper surface of the grinding blade 400 is suppressed by the washer 391, and the lower surface facing the surface of the work material is tightened by the nut 392, so that the grinding blade 400 is integrated with the output shaft 300 coaxially (rotational axis O). It is fixed to rotate.

[1-4. Cover]
The grinding device 100 is equipped with a cover 500 for sucking the grinding device 100 to the work surface and preventing scattering of dust generated by the processing by the grinding blade 400.

The cover 500 includes a peripheral wall portion 520, a suction port 525, and a diaphragm 540. A work space S is formed inside the cover 500.
The peripheral wall portion 520 is provided with a cylindrical member 523 arranged so as to cover the periphery of the grinding blade 400 and opened on the side (lower side) facing the surface of the work material, and a connecting tool 521 connected to the cylindrical member 523. including. In the present embodiment, as shown in FIG. 4, the grinding blade 400 is located above the open end 510 of the cover 500 (that is, the open end of the cylindrical member 523) during non-grinding, and the work space S It is completely contained within. This can prevent the grinding blade 400 from accidentally coming into contact with another place. The peripheral wall portion 520 has rigidity that resists negative pressure when the air in the work space S is sucked (described later).

  The connecting tool 521 connected to the upper end of the peripheral wall 520 is an annular member along the upper end of the peripheral wall 520, and connects the diaphragm 540 and the blade amount adjusting unit 700.

  The diaphragm 540 (film body) seals the upper part of the peripheral wall portion 520 so as to ensure the airtightness of the work space S. The diaphragm 540 includes a flexible portion 543 and a fixed portion 545. The flexible portion 543 is a container shape having a through hole in the center, and the output shaft 300 is passed through the through hole, and the output shaft 300 is interlocked with the output shaft 300 via the cutting blade amount adjusting unit 700. It is fixed to. Therefore, the output shaft 300 can reciprocate in the direction of the rotation axis O while maintaining the sealed state of the work space S. The fixing portion 545 has a flange shape formed on the peripheral edge of the flexible portion, and is fixed to the connector 521. The diaphragm 540 is made of an elastic material such as rubber or elastomer.

  A suction port 525 is formed in the cylindrical member 523 of the peripheral wall 520 (see FIG. 2), and an exhaust hose 529 (see FIGS. 1 and 4) communicating with the work space S is connected through the suction port 525. Has been done. The exhaust hose 529 is connected to a suction unit such as a dust collector or a vacuum generator (not shown). By operating the suction unit, the air in the work space S is sucked and discharged through the suction port 525 and the exhaust hose 529.

  In the present embodiment, as shown in FIG. 4, the cover 500 is configured such that the opening end 510 is inclined at an angle θ from the orthogonal plane OP with respect to the protruding direction of the output shaft. By being configured to have such an inclined open end 510, the cover 500 has a guide function of determining and keeping constant an angle at which the grinding blade 400 is applied to the work surface 900. The angle θ may be a recommended angle of the grinding blade 400 with respect to the surface 900 of the work material, and may be 10 ° or more and 20 ° or less, preferably 15 ° or more and 20 ° or less with respect to the orthogonal plane OP. As a result, the operator can easily determine the angle of the grinding blade 400 with respect to the surface 900 of the work material, and can easily perform the operation while maintaining the recommended angle, so that the workability of the grinding operation can be improved. .

Inner circumferential area Sc of the open end 510 of the cover 500 (the area in the present embodiment is derived from the inner diameter Dc in FIG. 2), for example, 78.5 cm ² or more 707Cm ² or less, there preferably in 133cm ² or more 491Cm ² or less You may It is preferable that the inner peripheral area Sc is equal to or larger than the above lower limit because it is easy to support the own weight X of the grinding device 100 by suction. The fact that the inner peripheral area Sc is equal to or less than the above upper limit depends on the size of the inner peripheral area Sd of the flexible portion 543 of the diaphragm 540 (in this embodiment, the area derived from the inner diameter Dd in FIG. 2). It is preferable in that the grinding device 100 can be easily moved on the work surface 900 while being attracted to the work surface 900.

  The inner peripheral area Sd of the flexible portion 543 of the diaphragm 540 may be, for example, 25% or more and 75% or less, preferably 40% or more and 60% or less of the inner peripheral area Sc of the opening end 510 of the cover 500. It is preferable that the ratio of the inner peripheral area Sd is equal to or more than the above lower limit because it is easy to move the grinding device 100 on the work surface 900 while adhering to the work surface 900. It is preferable that the inner peripheral area Sd is equal to or less than the above upper limit because it is easy to support the own weight X of the grinding device 100 by suction.

[1-5. Breathable sliding contact member]
In this embodiment, the breathable sliding contact member 600 is fixed to the opening end 510 along the entire circumference thereof. The breathable sliding contact member 600 in this embodiment is fixed to the surface of the open end 510. As a result, the fixed surface 611 on the upper surface of the breathable sliding contact member 600 is fixed to the opening end 510, while the sliding contact surface 619 on the lower surface is brought into contact with the work material surface 900 (described later in FIG. 5).

The breathable sliding contact member 600 may be made of a breathable material having breathability during compression, slidability, and compression elasticity.
The breathability at the time of compression of the breathable sliding contact member 600 does not block the void that connects the inside and the outside of the work space S even when the inside of the work space S of the cover 500 is sucked and compressed by the suction unit. It means the property of maintaining air permeability by securing it. Specifically, the gap is ensured even when pressed by a pressure equal to or higher than the pressure pressed by the surface of the open end 510 by the vacuum pressure (suction pressure) by the suction unit. Accordingly, it is possible to ensure an appropriate gas flow rate and exhibit good dust collecting performance, and in the state where the sliding contact surface 619 of the breathable sliding contact member 600 is pressed against the work material surface 900, The cutting material surface 900 can be easily moved. In the present embodiment, it is sufficient that the breathable sliding contact member 600 can secure the gap against the vacuum pressure (suction pressure) generated by the suction unit.

  The slidability of the breathable sliding contact member 600 is a property that enables movement with low friction while being pressed against the surface 900 of the work material.

Specifically, the coefficient of dynamic friction of the breathable sliding contact member 600 may be, for example, 0.17 or less. Accordingly, the work surface 900 can be easily moved in a state where the sliding contact surface 619 of the breathable sliding contact member 600 is pressed against the work surface 900 by suction pressure inside the work space S of the cover 500. You can
Further, the coefficient of dynamic friction of the breathable sliding contact member 600 may be, for example, 0.14 or more. Thereby, when the work material surface 900 is not a surface vertically below the grinding device 100 (for example, the work material surface 900 is a non-horizontal surface such as a vertical direction or a surface vertically above the grinding device 100). Even in the case), an operator who is moving the grinding device 100 in a state of being attracted to the work surface 900 can bear a small load to support the own weight of the grinding device 100.

Further, the static friction coefficient μ of the breathable sliding contact member 600 may be, for example, 0.21 or more. Thereby, when the work material surface 900 is not a surface vertically below the grinding device 100 (for example, the work material surface 900 is a non-horizontal surface such as a vertical direction or a surface vertically above the grinding device 100). Even in the case), it is easy to eliminate the burden of the operator supporting the own weight of the grinding device 100 when the grinding device 100 is stationary and is adsorbed to the work surface 900. Further, even if the operator releases his / her hand from the grinding device 100, the grinding device 100 may be completely adsorbed on the surface 900 of the work material and the drop due to its own weight may be easily prevented.
The static friction coefficient μ of the breathable sliding contact member 600 may be, for example, 0.3 or less. As a result, it is possible to reduce the burden on the operator when moving the grinding device 100 from the state in which the grinding device 100 is stationary and is adsorbed on the work surface 900.

The coefficient of friction of the breathable sliding contact member 600 is, for example, dry precast concrete (standard value of roughness coefficient 0.013 (coefficient range: 0.011 or more and 0.016 or less)) and the grinding device 100 (self-weight 3. 75 kg) can be obtained from the tensile resistance when suction is performed through the breathable sliding contact member 600 (static pressure 13 kPa). The roughness coefficient is expressed by the Manning's average formula (v = 1 / n · R ^2/3 · I ^1/2 , where v is the flow velocity (m / sec) and n is the roughness coefficient. , R can be derived from the diameter depth (fluid bed / wetting edge), and I indicates the gradient.).

  The compressive elasticity of the breathable sliding contact member 600 refers to the property of returning to the original state at the time of unloading after being loaded for a predetermined time. Thereby, even if the direction of the surface of the opening end 510 deviates from the direction of the work material surface 900 during work, the sliding contact surface 619 of the breathable sliding contact member 600 easily follows the work material surface 900. It is easy to maintain a negative pressure state in the work space S and to easily suppress dust scattering. The elastic force of the breathable sliding contact member 600 is smaller than the reaction force F (elastic force) of the expansion / contraction part 750 described later.

  From the viewpoint of ensuring good compression elasticity, the breathable material may be a single resin or a mixture of two or more resins such as polyolefin, polyester and polyamide. From the viewpoint of ensuring slidability, rubber and elastomer are removed from the resin at least in the portion of the breathable sliding contact member 600 that comes into contact with the surface 900 of the work material. In this embodiment, polyester is selected. Further, the breathable sliding contact member 600 may be formed by stacking breathable materials having different characteristics. For example, the breathable slidable contact member 600 may have a multi-layer structure in which a resin material having a better compressive elasticity is laminated with a resin material having a better slidability.

From the viewpoint of ensuring air permeability at the time of compression, the air-permeable material may have any form having continuous voids, and examples thereof include a fibrous body and a porous body. Examples of the fibrous body include non-woven fabric (according to JIS L0222) and felt. In this embodiment, a chemical fiber non-woven fabric or a chemical fiber felt is used. The basis weight of the fibrous body may be, for example, 0.15 g / cm ³ or more. As a result, good air permeability can be ensured. Moreover, the said basis weight may be 0.6 g / cm < ³ > or less. As a result, it is possible to ensure good compression elasticity.

As shown in FIG. 3, the width w of the sliding contact surface 619 of the breathable sliding contact member 600 is, for example, 10% or more, preferably 20% or more, of the outer diameter of the breathable sliding contact member 600 when not compressed. Good. Accordingly, since the area where the sliding contact surface 619 contacts the workpiece surface 900 can be sufficiently secured, the cover 500 can satisfactorily suck the workpiece surface 900. The width w may be, for example, 25% or less, preferably 35% or less, of the outer diameter of the breathable sliding contact member 600 when not compressed. This makes it easy to ensure the air permeability of the air-permeable sliding contact member 600.
The width w of the sliding contact surface 619 is equal to or larger than the width of the fixed surface 611. Accordingly, since the area where the sliding contact surface 619 contacts the workpiece surface 900 can be sufficiently secured, the cover 500 can satisfactorily suck the workpiece surface 900.

  The height h of the non-fixed portion of the breathable sliding contact member 600 and the portion below the open end 510 may be, for example, 50% or more of the width w. Thereby, even if the direction of the surface of the opening end 510 deviates from the direction of the work material surface 900 during work, the sliding contact surface 619 of the breathable sliding contact member 600 easily follows the work material surface 900. It is easy to control the scattering of dust. The height h may be, for example, 200% or less of the width w. As a result, even if the breathable sliding contact member 600 receives a compressive force or a compressive force and a frictional force, the state in which the sliding contact surface 619 is in contact with the workpiece surface 900 is stably maintained, so that the work space is maintained. The airtight state of S is kept stable, and dust is easily prevented from scattering.

  In the present embodiment, the breathable sliding contact member 600 is formed by hollowing out a breathable material into an annular shape that is continuous all around. Thereby, the airtightness in the work space S can be more preferably obtained. However, the breathable sliding contact member 600 is not limited to this embodiment. For example, the breathable material formed into a band shape is formed into an annular shape so that both ends thereof are butted and the thickness of the breathable material becomes the radial width. It may be configured.

[1-6. Cutting edge amount adjustment part and grip part]
The grinding apparatus 100 of the present embodiment includes a blade amount adjusting unit 700 that adjusts the blade amount of the grinding blade 400 by moving the output shaft 300, to which the grinding blade 400 is fixed, in the rotation axis O direction.

  The blade amount adjusting unit 700 is disposed on the upper portion of the cover 500 and mainly includes a pressing unit 710 and an expanding / contracting unit 750. The pressing portion 710 is a portion that reciprocates in the direction of the rotation axis O, and the expansion / contraction portion 750 is a portion that enables the reciprocating movement.

  The pressing portion 710 includes a first pressing member 712 that constitutes an upper portion thereof and a second pressing member 714 that constitutes a lower portion thereof. Each of the first pressing member 712 and the second pressing member 714 has a vertical through hole in the central portion. The first pressing member 712 and the second pressing member 714 are connected to each other with the flexible portion 543 of the diaphragm 540 being sandwiched between them. In this connection mode, since the through holes of the first pressing member 712 and the second pressing member 714 and the through hole of the flexible portion 543 of the diaphragm 540 are positioned so as to be substantially coaxial with each other, the output shaft 300 is The pressing portion 710 (the first pressing member 712 and the second pressing member 714) and the cover 500 (diaphragm 540) pass through and project into the cover 500.

  Further, the pressing portion 710 is configured to be connected to the output shaft 300. In the present embodiment, the first pressing member 712 of the pressing unit 710 is fixed to the gear case 220 fixedly connected to the output shaft 300 by the connecting protrusion 221 via the fixing member 711, so that the pressing unit 710 outputs. It is connected to the shaft 300. Accordingly, the reciprocating operation of the pressing portion 710 in the rotation axis O direction and the reciprocating operation of the output shaft 300 and the grinding blade 400 provided therein in the rotation axis O direction can be interlocked.

  The second pressing member 714 is configured such that the outer circumference thereof is smaller than the inner circumference of the connector 521. This configuration allows the second pressing member 714 to be loosely inserted into the inside of the connecting tool 521 while the diaphragm 540 is fixed, so that the pressing portion 710 is moved in the rotation axis O direction and downward (forward movement). ) Is possible.

  A flange portion is provided on the first pressing member 712 so as to project between the pressing surface 719 that constitutes the lower surface of the flange portion and the cover 500 (more specifically, the connecting member 521) in the rotation axis O direction. A stretchable portion 750 that stretches and shrinks is provided. Both ends of the expansion / contraction part 750 are fixed to the pressing surface 719 and the connection tool 521, respectively. In the present embodiment, the expansion / contraction part 750 is embodied by a compression coil spring having a spring axis extending in the direction of the rotation axis O.

  The expandable part 750 expands and contracts to enable the pressing part 710 to reciprocate in the direction of the rotation axis O. The expansion / contraction part 750 contracts when the pressing part 710 is moved in the direction of the rotation axis O and in the downward direction (forward operation), and at the same time, generates a reaction force toward the pressing surface 719 by expansion / contraction. As a result, the grinding blade 400 fixed to the output shaft 300 that is interlocked with the pressing surface 719 is slightly pulled back to the side opposite to the work surface 900, and the pressing force of the grinding blade 400 on the work surface 900 is relaxed. Fine-tune. The blade amount adjusting unit 700 in the present embodiment adjusts the blade amount of the grinding blade 400 in order to finely adjust the pressing force of the grinding blade 400 to the work surface 900.

  The expansion / contraction part 750 may generate a reaction force F (elastic force) of, for example, 0 kgf or more and 35.2 kgf or less, preferably 1.0 kgf or more and 20 kgf or less, with respect to the pressing surface 719. It is preferable that the reaction force F is equal to or more than the lower limit value in that it is easy to prevent the pressing force of the grinding blade 400 against the workpiece surface 900 from becoming excessive, and if the reaction force F is equal to or less than the lower limit value, It is preferable in that it is easy to prevent the pressing force of the grinding blade 400 against the work surface 900 from becoming insufficient.

The expansion / contraction constant (spring constant in this embodiment) of the expansion / contraction part 750 and the stroke (contraction length) to be secured can be determined based on the desired value of the reaction force F. For example, the expansion and contraction constant may be 0.5 N / mm or more and 35.2 N / mm or less, preferably 1.0 N / mm or more and 20 N / mm or less. It is preferable that the expansion and contraction constant is equal to or more than the above lower limit, because the stroke to be secured can be appropriately short, and the height of the grinding device 100 in the direction of the output shaft 300 can be appropriately compacted, and the above upper limit. When the value is equal to or less than the value, it is easy to adjust the pressing force of the grinding blade 400, and the stroke of the grinding blade 400 and the pressing portion 710 accompanied therewith are appropriately secured, so that the grinding blade 400 is kept at the workpiece surface 900. It is preferable for the operator to easily recognize that the touching is a feeling that the pressing portion 710 and the like have moved. It should be noted that the above-mentioned expansion / contraction constant corresponds to the sum of expansion / contraction constants of the respective expansion / contraction parts when the expansion / contraction part 750 is composed of a plurality of parts.

  In the present embodiment, the grip portion 800 is fixed to the pressing portion 710 in a pair (see FIG. 1). Each of the pair of gripping portions 800 extends along a plane orthogonal to the rotation axis O and is arranged so as to form 180 ° with respect to the rotation axis O. Therefore, the operator can easily operate the grinding device 100 by gripping the grip portion 800 with both hands. For example, the grinding device 100 can be easily moved in the direction of the work surface 900.

[1-7. Modification]
In the present embodiment, an example in which the breathable sliding contact member 600 is provided at the opening end 510 of the cover 500 has been described, but the present invention is not limited to this aspect. For example, instead of the breathable sliding contact member 600, a material that has slidability and compression elasticity and does not have breathability when compressed, or a material that has slidability and does not have compression elasticity and breathability when compressed, Good. Examples of these substitute materials include fibrous materials and porous materials, and in the case of a porous material, a closed cell type porous material may be used. The static friction coefficient μ of these alternative materials may be the same as or different from that of the breathable sliding contact member 600. Those skilled in the art can appropriately determine that the relationship between the force Y (kgf) in the direction opposite to the gravity acting on the grinding device and the self-weight X (kgf) of the grinding device satisfies equation (I) described later.

  In this embodiment, the container diaphragm is used as the diaphragm 540, but the shapes of the flexible portion and the fixed portion are not limited to this. For example, instead of the container-shaped diaphragm 540, any film body may be used as long as it is a sealing material having a flexible portion and a fixed portion, such as a flat plate-shaped diaphragm and a folded diaphragm. Those skilled in the art can appropriately select these film bodies according to a desired stroke of the grinding blade 400 and the like.

  In the present embodiment, the mode in which the blade amount adjusting unit 700 is provided is described, but the grinding device 100 is not limited to this mode. For example, if the pressing force of the grinding blade 400 against the work material surface 900 by the suction in the cover 500 by the suction unit is appropriate even if there is no reaction force of the expansion / contraction unit 750 as described above, the blade amount adjusting unit. 700 may be excluded. For example, the static friction coefficient μ is larger than that of the grinding apparatus 100 having the blade adjustment 700, the suction force by the suction unit is small, and the pressure regulating valve described later is included.

[1-8. Use of grinding equipment]
When the grinding apparatus 100 is used, by turning on a power switch (not shown) provided on the motor case 210, electric power is supplied to the electric motor, and the grinding blade 400 rotates together with the output shaft 300. Further, by turning on a power switch of a suction unit (not shown), an air flow from the working space S through the suction port 525 into the exhaust hose 529 is generated.

  When the suction unit is operating, as shown in FIG. 5, when the sliding contact surface 619 of the breathable sliding contact member 600 is brought into contact with the work material surface 900, the cover 500 is attracted to the work material surface 900. . When the work space S of the cover 500 is depressurized by the suction force generated by the suction unit, the flexible portion 543 of the diaphragm 540 is pulled toward the work surface 900. In association with the movement of the flexible portion 543, the output shaft 300 and the grinding blade 400 fixed thereto are also drawn toward the work surface 900, and the grinding blade 400 comes into contact with the work surface 900. Therefore, by operating the suction unit, the grinding blade 400 can be easily pressed (biased) against the work surface 900. Thereby, the grinding process is performed. In other words, the force of the operator is not required to press the grinding blade 400 against the work surface 900, and the grinding blade 400 is pressed against the work surface 900 as long as the suction unit is operated. Can be kept and continue to grind. Therefore, the grinding apparatus 100 of the present invention has excellent workability.

  In particular, in the present embodiment, as described above, the opening end 510 of the cover 500 has an inclined structure so that the grinding blade 400 can be applied to the work surface 900 at the recommended angle. And without requiring skill, the grinding blade 400 can be pressed at the recommended angle and can be maintained by simply operating the suction unit.

  At this time, the grinding blade 400 fixed to the output shaft 300 is pulled toward the work surface 900 in the direction of the rotation axis O by the suction force generated by the suction unit, and at the same time, the pressing force of the output shaft 300 is fixed. The part 710 also works in the same direction. Therefore, the expansion / contraction portion 750 provided between the movable pressing surface 719 of the pressing portion 710 and the immovable connecting member 521 of the cover 500 contracts in conjunction with the pressing surface 719. At the same time, the contracted expanding / contracting portion 750 urges the pressing portion 710 and the grinding blade 400 interlocking with the pressing portion 710 in a direction opposite to the direction toward the work surface 900 by the reaction force (elastic force) that urges the pressing surface 719. The pullback force also acts. Therefore, even if the pulling of the grinding blade 400 to the work material surface 900 by the operation of the suction unit alone presses the grinding blade 400 against the work material surface 900 with excessive force, The pressing force can be appropriately adjusted by the action of the appropriate pullback by the reaction force.

  When the surface 900 of the work material is not horizontal, the force Y (kgf) in the direction opposite to gravity acts on the grinding device 100 when the suction unit is operating due to the suction pressure. In addition, when the above-mentioned work material surface 900 is not horizontal, the case where the work material surface 900 is a top surface forming 180 ° with respect to the horizontal plane is included. In FIG. 5, the case where the work material surface 900 is a vertical surface that makes an angle of 90 ° with the horizontal plane is illustrated.

The force Y acting in the vertical direction of the grinding device 100 due to the force Y in the direction opposite to the gravity becomes smaller than the own weight X (kgf) of the grinding device 100. Specifically, the relationship between the force Y and the own weight X when the suction unit is operating satisfies the relationship of the following formula (I).
Y / X> 1 (I)
In this case, the suction pressure (negative pressure) inside the cover 500 acts so that the force Y in the direction opposite to the gravity becomes larger than the own weight X of the grinding apparatus 100, so that the operator applies it to the work surface 900 which is not horizontal. Even if the grinding device 100 is released from the hand, the grinding device 100 does not drop due to its own weight X. Therefore, it is possible to eliminate the burden of the operator supporting the own weight X of the grinding device 100. When the suction force of the suction unit reaches a level that satisfies the relationship of the above formula (I), the suction state is particularly described as suction.

  It should be noted that the weight of the suction unit and the weight of the exhaust hose 529 among the components of the grinding apparatus 100 are excluded from the weight X of the grinding apparatus 100. Specifically, the own weight X of the grinding device 100 may be, for example, 14 kgf or less, preferably 10 kgf or less. It is preferable that the range of the own weight X is equal to or less than the upper limit value because it is easy for the operator to save energy required for the suction unit in order to eliminate the burden of supporting the own weight X of the grinding apparatus 100. The lower limit value within the range of the weight X of the grinding device 100 is not particularly limited, but is usually about 2.5 kgf.

In addition, the grinding device 100 operates the suction unit in a state in which the force Y in the direction opposite to gravity, the coefficient of static friction μ of the work surface 900 and the cover 500 are in contact with the work surface 900. In this case, the relationship with the actual suction force N (kgf) with which the cover 500 sucks the workpiece surface 900 is represented by the following formula (II).
Y = μN (II)

In this relationship, the actual suction force N, the inner peripheral area Sc (cm ² ) of the opening end 510 of the cover 500, the inner peripheral area Sd (cm ² ) of the flexible portion, the vacuum degree P (kPa) by the suction unit, And the reaction force F (kgf) of the expansion / contraction part 750 may satisfy the relationship of the following formula (IV).
N = P (Sc-Sd) + F (IV)

  Note that when the work material surface 900 is a top surface that makes an angle of 180 ° with the horizontal plane, unlike in FIG. 5, in a state where the grinding device 100 is stationary without being applied a load in the direction of the top surface, Since the friction against the own weight X does not work, the static friction coefficient μ in this state is regarded as 1.

  The set value of the vacuum degree P of the suction unit may be, for example, 1 kPa or more and 90 kPa or less, preferably 13 kPa or more and 15 kPa or less. It is preferable that the degree of vacuum P is equal to or higher than the lower limit value in order to easily press the grinding blade 400, and if the degree of vacuum P is equal to or lower than the upper limit value, the grinding device 100 is used as the work material while being attracted to the work material surface 900. It is preferable because it can be easily moved on the surface 900.

Further, the relationship between the force Y and the own weight X when the suction unit is operating may satisfy the relationship of the following formula (V).
Y / X <5 (V)
In this case, it is preferable that the grinding device 100 can be easily moved on the work surface 900 while being attracted to the work surface 900.

  At this time, the breathable sliding contact member 600 is also compressed. The relative positional relationship between the open end 510 of the cover 500 and the fixed surface 611 of the breathable sliding contact member 600 is the same as in the case of FIG. Therefore, the breathable sliding contact member 600 is compressed by the suction force. Due to the air permeability at the time of compression of the air-permeable sliding contact member 600, a space that communicates the work space S with the outside is maintained even during suction, so an appropriate small amount of outside air is sucked into the work space S through the space. However, the work space S is satisfactorily decompressed by allowing only this suction.

  Therefore, the grinding device 100 favorably sticks to the work surface 900. Therefore, even if the surface 900 of the work material is not horizontal, the burden of the operator supporting the own weight of the grinding device 100 is reduced.

  Since the breathable sliding contact member 600 has slidability, even if the grinding blade 400 is lifted from the work material surface 900 as shown in FIG. 5, it smoothly moves on the work material surface 900 while maintaining the suction state. It is also easy to do.

  Further, since the breathable sliding contact member 600 has compressive elasticity, even if the direction of the surface of the opening end 510 deviates from the direction of the work material surface 900 while moving on the work material surface 900, the air permeability is improved. Since the sliding contact surface 619 of the sliding contact member 600 easily follows the work surface 900, it is possible to maintain a good suction state.

  The dust generated by the grinding process is discharged along with the airflow from the working space S through the suction port 525 into the exhaust hose 529. The breathable sliding contact member 600 has breathability at the time of compression, so that an appropriate small amount of outside air is sucked into the work space S through the voids secured during the compression, so that the work material surface 900 and the opening end 510 of the cover 500 are close to each other. However, since the airflow from the outside to the work space S is constantly generated, it is possible to suppress the scattering of dust to the outside.

  Due to the slidability, the breathable sliding contact member 600 can be easily moved while keeping the state in which the cover 500 is adsorbed on the surface 900 of the work material and the scattering of dust is suppressed.

  Further, since the breathable sliding contact member 600 has compressive elasticity, even if the direction of the surface of the opening end 510 deviates from the direction of the surface 900 of the work material during the grinding process or the movement during the grinding process. Since the sliding contact surface 619 of the breathable sliding contact member 600 easily follows the work surface 900, the suction state can be kept good. Therefore, the contact property with the surface 900 of the work material is good, and the scattering of dust is easily suppressed.

  Further, when the diaphragm 540 interposed between the cover 500 and the blade amount adjusting unit 700 is made of an elastic material, in the state of FIG. When a load is applied to the work piece surface (for example, the grip portion 800 fixed to the blade amount adjusting portion 700 or the motor case 210 may be loaded in that direction), as shown in FIG. It is possible to slightly change the inclination of the blade amount adjusting unit 700 while adhering to 900. The outer circumference of the second pressing member 714 is smaller than the inner circumference of the connecting member 521 so that the second pressing member 714 forming the pressing portion 710 of the blade amount adjusting unit 700 can be freely inserted into the connecting member 521 of the cover 500. Therefore, such relative position change is allowed while maintaining the sealed state.

  As a result, the rotation axis O of the output shaft 300 fixed to the blade amount adjusting unit 700 deviates from the rotation axis O before the change (specifically, as shown in FIG. 6, the changed rotation axis O changes. It is possible to finely adjust the angle at which the grinding blade 400 hits the work surface 900 by shifting in the direction intersecting with the previous rotation axis O). Therefore, even if the grinding blade 400 wears at a specific angle that hits the work surface 900 by grinding in the state of FIG. 5, by finely adjusting the angle of the grinding blade 400 as shown in FIG. Grinding can be performed using a surface different from the worn surface. It should be noted that the angle for fine adjustment (indicated by an angle θ ′ in the figure; 0 ° when no load is applied) may be more than 0 ° and 3 ° or less.

  In the present invention, as described above, since the grinding blade 400 is pressed against the work material surface 900 by the suction unit without requiring the force of the operator, the angle of the grinding blade 400 during the grinding process When performing fine adjustment, the operator only has to apply a load to the blade amount adjusting unit 700 in a direction intersecting the rotation axis O. Therefore, it becomes easy to adjust the angle of the grinding blade 400 during the grinding process.

In addition, in the case of the grinding device which does not have the blade amount adjusting unit 700 as described in the modification of the first embodiment, the actual suction force N and the opening end 510 of the cover 500 are satisfied in the relationship of the above formula (II). inner circumferential area Sc of ^(cm 2), the inner circumference area Sd of the flexible portion ^(cm 2), the degree of vacuum P (kPa) by the suction machine section, and a reaction force of the stretchable portion 750 F (kgf), the following formula The relationship of (III) is satisfied.
N = P (Sc-Sd) (III)

[2. Other Embodiments]
7 to 12 show a grinding device according to another embodiment. In other embodiments, points different from the first embodiment will be described, and description of the same points will be omitted. Further, the modified examples described in the first embodiment can be applied to other embodiments as appropriate, and elements different from the first embodiment can be appropriately combined with each other.

[2-1. Second Embodiment]
FIG. 7 is a partial cross-sectional view of a grinding device which is an example of the second embodiment, and corresponds to a part of FIG. 3 of the first embodiment. In the grinding device 100a shown in FIG. 7, the breathable sliding contact member 600a is fixed to the inner wall near the opening end 510a of the cover 500a via the holding member 650a. The holding member 650a clamps the upper side surface of the breathable sliding contact member 600 to fix the fixed surface 611a. Further, the holding member 650a is provided with a fitting portion (fitting protrusion in this example) on the side surface, and the fitting portion (fitting concave portion in this example) provided on the inner wall near the opening end 510a of the cover 500a. It is fitted and fixed. A gasket may be interposed between the holding member 650a and the inner wall near the opening end 510a in order to improve the airtightness in the work space Sa.

  FIG. 8 is a partial cross-sectional view of a grinding device that is another example of the second embodiment, and corresponds to a part of FIG. 3 of the first embodiment. In the grinding device 100b shown in FIG. 8, the breathable sliding contact member 600b is fixed to the surface of the open end 510b of the cover 500b via the holding member 650b. The holding member 650b fixes the fixed surface 611b by sandwiching the upper side surface of the breathable sliding contact member 600b. Further, the holding member 650b is provided with a fitting portion (fitting protrusion in this example) on the upper surface, and is fitted into a fitting portion (fitting concave portion in this example) provided on the open end 510b surface of the cover 500b. Is fixed.

In both the example of FIG. 7 and the example of FIG. 8 of the second embodiment, even when the breathable sliding contact members 600a, 600b are compressed, the breathable sliding contact members 600a, 600b with respect to the open ends 510a, 510b are provided. Similar to the first embodiment, the relative positions of the fixing surfaces 611a and 611b do not change. That is, in either case, the breathable sliding contact members 600a and 600b are fixed to the open ends 510a and 510b.
Further, in both the example of FIG. 7 and the example of FIG. 8 of the second embodiment, the holding members 650a and 650b may be configured to be detachable from the covers 500a and 500b. As a result, only the breathable sliding contact members 600a and 600b can be replaced.

[2-2. Third Embodiment]
FIG. 9 is a partially cutaway partial sectional view of the grinding device of the third embodiment and corresponds to a part of FIG. 4 of the first embodiment. In the grinding device 100c shown in FIG. 9, the opening end 510c of the cover 500c is configured to be parallel to the plane orthogonal to the rotation axis O. The grinding blade 400c is formed in a cup shape around the rotation axis O, and the entire grinding surface of the grinding blade 400c extending to the orthogonal surface is brought into contact with the workpiece surface 900 to perform grinding. .

[2-3. Fourth Embodiment]
FIG. 10 is a partial cross-sectional view of the grinding device of the fourth embodiment and corresponds to FIG. 5 of the first embodiment. FIG. 11 is a partial cross-sectional view showing after the operation of the grinding device of the fourth embodiment.
The grinding device 100e shown in FIGS. 10 and 11 is the same as the grinding device 100 of the first embodiment, except that the blade amount adjusting unit 700e further includes a movable spacer 760e. The blade amount adjusting unit 700e in the present embodiment moves the output shaft 300, to which the grinding blade 400 is fixed during grinding, to the workpiece surface 900 side in the direction of the rotation axis O, and the grinding blade 400 is fixed during non-grinding. The output shaft 300 is moved back to the opposite side. That is, the blade amount adjusting unit 700e in the present embodiment adjusts the blade amount during grinding and non-grinding.

  The movable spacer 760e that configures the blade amount adjusting unit 700e of the grinding device 100e is provided between the cover 500 (the connecting member 521 in the present embodiment) and the pressing surface 719. The movable spacer 760e may have any configuration as long as it can change the distance between the cover 500 and the pressing surface 719. In the present embodiment, the movable spacer 760e is a rigid member, and one end of the movable spacer 760e is rotatably fixed to one of the cover 500 and the pressing portion 710, specifically, the cover 500.

  When the movable spacer 760e is moved while the grinding blade 400 is pressed against the workpiece surface 900 as shown in FIG. 10, the cover 500 is resisted against the negative pressure in the work space S as shown in FIG. And the pressing surface 719 can be widened. Thereby, the grinding blade 400 can be separated from the work surface 900.

  By repeating the state of FIG. 10 and the state of FIG. 11, the operator does not apply a load in the direction of the rotation axis O on the workpiece surface 900 that does not need to be ground by holding the grip portion 800 of the grinding device 100e. The work piece surface 900 can be moved, and on the work material surface 900 that needs to be ground, the grinding blade 400 can be moved in contact with the work material surface 900. Since this series of work is performed while the cover 500 is adsorbed on the surface 900 of the work material, the grinding work can be performed from beginning to end while preventing scattering of dust. Further, when the grinding device 100e is removed from the work material surface 900 in the state of FIG. 11, the grinding blade 400 is housed in the cover 500 as compared with the case of peeling from the state of FIG. However, it is preferable because it can be removed.

[2-4. Fifth Embodiment]
FIG. 12 is a schematic partial cross-sectional view of the grinding device of the fifth embodiment and corresponds to FIG. 2 of the first embodiment.
The grinding device 100f shown in FIG. 12 is the same as the grinding device 100 of the first embodiment except that a pressure regulating valve 527f is included.

  In this embodiment, the pressure regulating valve 527f is provided on the peripheral wall portion 520f of the cover 500f so that a gas communication path inside and outside the cover 500f is formed when the suction pressure (negative pressure) inside the cover 500f becomes excessive. Is configured. As a result, even if the suction pressure in the cover 500f by the suction unit becomes excessive without the pressure regulating valve 527f, it is possible to adjust to a proper negative pressure. When the suction pressure in the cover 500f becomes excessive, for example, the grinding blade 400 is pressed against the workpiece surface 900 with an excessive force, so that the pressing force needs to be relaxed, and the cover 500f is not covered. There is a case where it is necessary to weaken the suction force (for example, by adjusting so as to satisfy the above formula (V)) to facilitate the movement because the suction force on the surface of the cutting material 900 is too strong and the movement becomes difficult. To be

  In the present embodiment, the one having the same blade amount adjusting unit 700 as in the first embodiment has been described, but as a modified example of the present embodiment, the blade amount adjusting unit 700 may not be provided. In this case, the grip portion can be directly fixed to the cover 500f. In this modified example, unlike the aspect in which the blade amount adjusting unit 700 is provided, in order to adjust the pressing force of the grinding blade 400 against the workpiece surface 900, the pressure regulating valve 527f is used instead of the action of the reaction force of the expansion / contraction unit. Utilizes the action of pressurization.

[2-5. Sixth Embodiment]
FIG. 13 is a partial cross-sectional view of the grinding device of the sixth embodiment and corresponds to a part of FIG. 2 of the first embodiment. FIG. 14 is a partially cutaway partial sectional view of the grinding device of the sixth embodiment, and corresponds to a part of FIG. 6 of the first embodiment. The grinding device 100g shown in FIGS. 13 and 14 does not have a structure corresponding to the blade amount adjusting unit 700 and the diaphragm 540 in the first embodiment. Therefore, as shown in FIG. 14, the grinding blade 400 is fixedly set at the amount of the blade to be brought into contact with the work surface 900 when the breathable sliding contact member 600 is pressed against the work surface 900. Has been done. Since the grinding device 100g of the present embodiment does not have the ability to adjust the amount of cutting edge, the grip portion 800g is fixed to the connector 521g of the cover 500. Further, since the grinding blade 400 does not move in the output shaft direction, a gasket may be used as a sealing material instead of the diaphragm 540.

  In this case, the actual suction force N (which satisfies the relationship of the above formula (I)) with which the cover is attracted to the workpiece surface 900 by the suction unit is determined by the vacuum degree P by the suction unit and the inner peripheral area of the cover opening end. It is represented by the product of Sc.

  When it is desired to increase the pressing force of the grinding blade 400 or when the grinding blade 400 is worn out, the height and the compression elasticity of the breathable sliding contact member 600 are used to lightly press the gripping portion 800g or the suction portion. It is possible to obtain a state in which the grinding blade 400 is preferably pressed against the surface 900 of the work material by changing the setting of 1 to increase the suction pressure.

[3. Correspondence between each part of the embodiment and each component of the claims]
In the present invention, the grinding devices 100, 100a, 100b, 100c, 100e, 100f, 100g of the embodiment correspond to the “grinding device” of the claims, the housing 200 corresponds to the “housing”, and the output shaft 300 corresponds to the “housing”. To the output shaft, the grinding blades 400 and 400c correspond to "grinding blades", the covers 500, 500a, 500b, 500c and 500f correspond to "covers", and the open ends 510, 510a, 510b and 510c correspond to "grids". The peripheral wall portions 520 and 520f correspond to the "peripheral wall portion", the suction port 525 corresponds to the "suction port", the pressure regulating valve 527f corresponds to the "pressure regulating valve", and the breathable sliding contact member corresponds to the "opening end". 600, 600a, and 600b correspond to the "breathable sliding contact member", the diaphragm 540 corresponds to the "membrane", the flexible portion 543 corresponds to the "flexible portion", and the fixing portion 545 is the "fixed portion". Part ", the blade amount adjusting part 700 corresponds to the" blade amount adjusting part ", the pressing surface 719 corresponds to the" pressing surface ", the expansion part 750 corresponds to the" expansion part ", the grip part 800, 800 g corresponds to the “holding part”, the work material surface 900 corresponds to the “surface of the work material”, the direction of the rotation axis O corresponds to the “projection direction of the output shaft”, and the orthogonal plane OP is “ It corresponds to the “orthogonal plane”, and the angle θ corresponds to the “angle”.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

100, 100a, 100b, 100c, 100e, 100f, 100g Grinding machine 200 Housing 300 Output shaft 400, 400c Grinding blades 500, 500a, 500b, 500c, 500f Covers 510, 510a, 510b, 510c Open ends 520, 520f Circumferential wall 525 Suction port 527f Pressure regulating valve 540 Diaphragm (membrane)
543 Flexible part 545 Fixed part 600, 600a, 600b Breathable sliding contact member 700, 700e Cutting blade amount adjusting part 719 Pressing surface 750 Stretching part 800, 800g Gripping part 900 Workpiece surface O Rotation axis (rotation axis direction O is (Matches with the protruding direction of the output shaft 300)
OP orthogonal plane θ angle

Claims (7)

A grinding device for grinding the surface of a work material,
A housing that houses the drive mechanism,
An output shaft protruding from the drive mechanism,
A grinding blade fixed to the output shaft and extending along a plane orthogonal to the output shaft;
A cover including a peripheral wall portion that opens on a side to be opposed to the surface of the grinding blade and covers the entire circumference of the grinding blade, and a suction port,
Including a suction unit connected to the suction port,
The weight X (kgf) of the grinding device and the force Y (kgf) in the direction opposite to gravity, which is generated when the suction unit is operated with the open end of the cover in contact with the surface of the work material. ) And the relationship between the following formula (I):
Y / X> 1 (I)
Meet the,
The output shaft is capable of reciprocating in the protruding direction from the drive mechanism,
Grinding, which includes a film body that seals the side opposite to the side to be opposed of the peripheral wall portion and includes a flexible portion that is operably connected to the output shaft and a fixing portion that is fixed to the peripheral wall portion. apparatus. The force Y (kgf) in the direction opposite to the gravity, the static friction coefficient μ at the open end of the cover with respect to the surface of the work material, and the state in which the cover is brought into contact with the surface of the work material The following formula (II) that is satisfied by the actual suction force N (kgf) that the cover adsorbs to the surface of the work material when the suction unit is operated:
Y = μN (II)
The suction force N (kgf), the inner peripheral area Sc (cm ² ) of the opening end of the cover, the inner peripheral area Sd (cm ² ) of the flexible portion, and the vacuum by the suction unit. The relationship with the degree P (kPa) is represented by the following formula (III):
N = P (Sc-Sd) (III)
Meet, grinding apparatus according to claim 1. Including a blade amount adjusting unit for adjusting the position of the grinding blade in the protruding direction,
The blade amount adjusting portion has a pressing surface provided on the side of the housing that should face the housing so as to be interlocked with the output shaft, and is provided between the pressing surface and the cover and in the protruding direction. The grinding device according to claim 1 , further comprising a stretchable portion that stretches and shrinks. The force Y (kgf) in the direction opposite to the gravity, the static friction coefficient μ at the open end of the cover with respect to the surface of the work material, and the state in which the cover is brought into contact with the surface of the work material The following formula (II) that is satisfied by the actual suction force N (kgf) that the cover adsorbs to the surface of the work material when the suction unit is operated:
Y = μN (II)
In relation to the actual suction force N (kgf), the inner peripheral area Sc (cm ² ) of the opening end of the cover, the inner peripheral area Sd (cm ² ) of the flexible portion, and the vacuum by the suction unit. Degree P (kPa), and reaction force F (kgf) that the expansion and contraction portion urges the pressing surface when the suction unit is operated while the cover is in contact with the surface of the work material. And is expressed by the following formula (IV):
N = P (Sc-Sd) + F (IV)
The grinding device according to claim 3 , which satisfies the above condition. The grinding device according to claim 4 , wherein the reaction force F of the expandable portion is 0 kgf or more and 35.2 kgf or less. The static friction coefficient μ is 0.21 or more, the grinding apparatus according to any one of claims 2, 4 and 5. The grinding device according to any one of claims 2 and 4 to 6 , wherein the degree of vacuum P by the suction unit is 1 kPa or more and 90 kPa or less.

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