Working part structure of belt sander, accessory of belt sander, and belt sander

Abstract

The invention provides a working part structure of an abrasive belt polishing machine, an accessory and the abrasive belt polishing machine, wherein an abrasive belt is more difficult to fall off. An attachment, which is a working part of a belt sander, is provided with a drive wheel (32) to which an abrasive belt (B) is attached. The belt speed, which is the speed of the abrasive belt (B), is 8 m / s or less, or can be set to 8 m / s or less. The driving wheel (32) is provided with a driving wheel belt contact part (TD) and a flange part (222), wherein the driving wheel belt contact part (TD) is in contact with the abrasive belt (B), and the flange part (222) is adjacent to the driving wheel belt contact part (TD).

Description

Technical Field

[0001] This invention relates to the structure of the working part of a belt polisher for mounting a sanding belt, accessories for the belt polisher, and the belt polisher itself. Background Technology

[0002] As shown in International Publication No. 2008 / 084265 (Patent Document 1), a joint device for grinding and polishing is known. In this device, an annular belt G for grinding and polishing is attached to a drive roller C, a bearing roller D, and a rotating roller E.

[0003] The drive roller C is driven by a plug (not shown) and a commercial power supply. The rotating roller E is positioned at the front end. The bearing roller D is positioned between the drive roller C and the rotating roller E in the front-rear direction.

[0004] In this device, a joint is arranged on the bearing roller D. This device is a joint-type device.

[0005] Furthermore, when the device is modified to include a joint in the drive roller C, the modified device becomes a longitudinally arranged two-joint type device. The longitudinally arranged two-joint type is a type with two joints arranged in the front-to-back direction.

[0006] Furthermore, as shown in European Patent Application Publication No. 1647362 (Patent Document 2), a two-strand belt abrasive grinder is known. This belt abrasive grinder has a joint that allows one of the two strands to move. This belt abrasive grinder is a two-strand, one-joint type device.

[0007] Guide rollers 24 and 26 are respectively provided at the ends of the two strands. A drive pulley 22 is provided at the root of the two strands. An annular sanding belt 28 is attached to the drive pulley 22 and the guide rollers 24 and 26.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: International Publication No. 2008 / 084265

[0011] Patent Document 2: European Patent Application Publication No. 1647362 Summary of the Invention

[0012] In commercially powered devices such as those described in International Publication No. 2008 / 084265 (Patent Document 1), the annular belt G has a wider speed range, and a flange is provided on the drive roller C.

[0013] However, in tubular belt sanders where the belt speed is slow enough to meet certain requirements, no flange is provided on the drive roller. The reason for this is to prevent the flange from coming into contact with the workpiece. A tubular belt sander with a belt speed slow enough to meet certain requirements is used for grinding tubular parts of indoor structures, such as railings.

[0014] Therefore, in tubular belt sanders where the belt speed is slower than specified, the belt is more likely to fall off.

[0015] In addition, the height of the flange of the drive pulley 22 in European Patent Application Publication No. 1647362 (Patent Document 2) is not high enough, and the sand belt is still relatively easy to fall off.

[0016] Furthermore, in belt polishers, it is desirable to prevent damage to the workpiece when the flange comes into contact with it.

[0017] Accordingly, one of the objectives of the present invention is to provide a structure of the working part of a belt polisher that makes it more difficult for the abrasive belt to fall off, accessories for the belt polisher, and the belt polisher itself.

[0018] In addition, another objective of the present invention is to provide a structure of the working part of a belt grinder that can suppress damage to the workpiece when the flange comes into contact with the workpiece, an accessory for the belt grinder, and the belt grinder.

[0019] This specification discloses a working section structure for a first belt sander. This first working section structure can be: a working section in a belt sander used for performing operations on a workpiece. The first working section structure may include: a drive wheel for mounting the sanding belt. It can be configured such that the speed of the sanding belt, i.e., the belt speed, is 8 m / s or less, or can be set to 8 m / s or less. The drive wheel may have: a portion that contacts the sanding belt, i.e., a belt contact portion. The drive wheel may have: a flange portion adjacent to the belt contact portion.

[0020] Furthermore, this specification discloses a working section structure for a second belt sander. This second working section structure can be: a working section in a belt sander used for performing operations on a workpiece. The second working section structure can include: a drive wheel for mounting the sanding belt. The drive wheel can have: a portion that contacts the sanding belt, i.e., a belt contact portion. The drive wheel can have: a flange made of synthetic resin adjacent to the belt contact portion.

[0021] Invention Effects

[0022] According to the present invention, a working part structure of a belt polisher that makes it more difficult for the abrasive belt to fall off, accessories for a belt polisher, and a belt polisher can be provided.

[0023] Furthermore, according to the present invention, a structure of the working part of a belt grinder that can suppress damage to the workpiece when the flange collides with the workpiece, an accessory for the belt grinder, and the belt grinder can be provided. Attached Figure Description

[0024] Figure 1 This is a left view of a tubular belt sander according to the first embodiment of the present invention.

[0025] Figure 2 yes Figure 1 A magnified stereoscopic view of the front of a tubular belt sander, viewed from the rear.

[0026] Figure 3 yes Figure 1 A 3D view of the drive wheel of a tubular belt sander.

[0027] Figure 4 yes Figure 3 A cross-sectional view of the drive wheel, passing through the center in the front-rear direction and extending in the up, down, left, and right directions.

[0028] Figure 5 yes Figure 1 A cross-sectional view of the first driven wheel of a tubular belt sander, passing through the center in the front-to-back direction and extending in the up, down, left, and right directions.

[0029] Figure 6 yes Figure 1 A cross-sectional view of the second driven wheel of a tubular belt sander, passing through the center in the front-to-back direction and extending in the up, down, left, and right directions.

[0030] Figure 7 This is a perspective view of the drive wheel according to the second embodiment of the present invention.

[0031] Figure 8 yes Figure 7 A cross-sectional view of the drive wheel, passing through the center in the front-rear direction and extending in the up, down, left, and right directions.

[0032] Figure 9 This is a perspective view of the drive wheel according to the third embodiment of the present invention.

[0033] Figure 10 yes Figure 9 A cross-sectional view of the drive wheel, passing through the center in the front-rear direction and extending in the up, down, left, and right directions.

[0034] Explanation of reference numerals in the attached figures

[0035] 1… Belt sander; 4… Accessories (working section); 12… Motor (brushless motor); 32, 300, 400… Drive wheel; 200… Inner wheel section; 202, 302, 402… Outer wheel section; 204, 404… Belt guide section; 222, 448… Drive wheel flange section (flange); 422… Drive wheel flange base section (part of flange); 446… Peripheral section (part of flange); B… Sanding belt; P… (Working section structure that prevents sanding belt from falling off); TD… Drive wheel belt contact section (belt contact section); a D …radius of the drive wheel contact area (radius of the contact area); b D …radius of the drive wheel flange (flange radius); c D …the gap between the drive wheel flanges (flange gap). Detailed Implementation

[0036] In one embodiment of the present invention, the distance between the central axis of the drive wheel and the end of the flange portion is also known as the flange portion radius b. D The distance between the central axis and the contact part of the belt, i.e., the radius 'a' of the contact part. D proportion (b) D / a D The value can be 1.1 or higher. In this case, the sanding belt is more difficult to detach.

[0037] In one embodiment of the present invention, the distance between the central axis of the drive wheel and the end of the flange portion is also known as the flange portion radius b. D The distance between the central axis and the contact part of the belt, i.e., the radius 'a' of the contact part. D proportion (b) D / a D The value can be 1.2 or higher. In this case, the sanding belt is more difficult to detach.

[0038] In one embodiment of the invention, the flange portion can be provided at both ends in the width direction of the contact portion. The distance between the central axis of the drive wheel and the end of either flange portion is also known as the flange radius b. D Subtract the distance between the central axis and the contact part of the belt, which is the radius 'a' of the contact part. D The result is a difference, which is divided by the distance between the two flanges, i.e., the flange spacing c. D The obtained value ((b) D -a D ) / c D The value can be above 0.05. In this case, the sanding belt is even more difficult to detach.

[0039] In one embodiment of the invention, the flange portion can be provided at both ends in the width direction of the contact portion. The distance between the central axis of the drive wheel and the end of either flange portion is also known as the flange radius b. D Subtract the distance between the central axis and the contact part of the belt, which is the radius 'a' of the contact part. D The result is a difference, which is divided by the distance between the two flanges, i.e., the flange spacing c. D The obtained value ((b) D -a D ) / c D The value can be below 1.00. In this case, the detachment of the sanding belt can be sufficiently suppressed, and the reduction in the ease of installation and removal of the sanding belt can be suppressed.

[0040] In one embodiment of the invention, the height of the flange is 3 mm or more. In this case, the sanding belt is more difficult to detach.

[0041] In one embodiment of the present invention, the belt speed, i.e., the belt velocity, can be set to 3.4 m / s or less. In this case, the belt is less likely to detach in a belt polisher with a relatively low belt speed.

[0042] In one embodiment of the invention, the flange portion may be made of synthetic resin. In this case, it is possible to suppress damage to the workpiece when the flange portion comes into contact with the workpiece.

[0043] In one embodiment of the present invention, the drive wheel may include an outer wheel portion having a flange. The drive wheel may also include an inner wheel portion disposed radially inward of the outer wheel portion. The outer wheel portion may be made of synthetic resin. The inner wheel portion may be made of metal. In this case, sufficient strength can be obtained in the portion directly connected to the output portion, i.e., the inner wheel portion, and damage to the workpiece can be suppressed by the outer wheel portion disposed radially outward of the inner wheel portion.

[0044] In one embodiment of the invention, the outer wheel portion may be made of polyamide. In this case, the chemical resistance of the outer wheel portion is improved.

[0045] In one embodiment of the invention, the outer wheel portion may have a rubber belt guide. The belt guide may be positioned axially inside the flange portion. The belt guide may have a belt contact portion. In this case, slippage of the abrasive belt relative to the drive wheel can be suppressed.

[0046] In one embodiment of the invention, part or all of the flange portion may be integral with the outer wheel portion. In this case, the outer wheel portion has a simple structure.

[0047] In one embodiment of the invention, the contact portion may include the end faces of multiple ribs. In this case, slippage of the sanding belt relative to the drive wheel can be suppressed.

[0048] Additionally, this specification discloses an accessory for a belt grinder. This accessory may have the working section structure of the aforementioned belt grinder.

[0049] Furthermore, this specification discloses a belt polisher. This belt polisher may have the working section structure described above.

[0050] In one embodiment of the invention, the belt sander may include a brushless motor as a drive source for the drive wheel. In this case, the belt sander becomes lighter, smaller, and has higher output.

[0051]

Example

[0052] Hereinafter, embodiments of the present invention will be described appropriately based on the accompanying drawings. This description includes variations of this embodiment. The present invention is not limited to this embodiment or its variations.

[0053] The directions in this method and the variations are for ease of explanation and may vary depending on the working conditions and the movement of the component in at least one direction.

[0054] [Method 1]

[0055] Figure 1 This is a left view of the tubular belt sander 1 according to the first embodiment of the present invention. Figure 2 This is a magnified three-dimensional view of the front of the tubular belt sander 1, viewed from the rear.

[0056] The tubular belt sander 1 has: a main body 2 and an accessory 4.

[0057] The tubular belt sander 1 can also be referred to as a drum belt sander, a tubular sander, or a drum-type sander. Attachment 4 can also be referred to as a component. In the tubular belt sander 1, attachment 4 is a working part for performing operations such as grinding on the workpiece. Furthermore, unlike the tubular belt sander 1 described below, the working part may be assembled to the main body 2 in a difficult-to-separate state; that is, attachment 4 may not be easily detachable from the main body 2.

[0058] exist Figure 1 In the middle, the left side shows the front of the tubular belt sander 1. Additionally, in... Figure 1 In the middle, the upper side is the upper side of the tubular belt sander 1.

[0059] The main body 2 is cylindrical with its central axis set in the front-to-back direction.

[0060] The main body 2 includes: a housing 10, a motor 12, a fan 14, a battery assembly 16, a battery 18, a controller 20, a connector 22, a speed adjustment dial 24, a main switch 26, a power transmission unit 28, and a main shaft 30 as an output unit.

[0061] In the main body 2, from the rear, are arranged in the following order: battery 18, battery assembly 16, controller 20, connector 22, motor 12, fan 14, power transmission unit 28, and main shaft 30.

[0062] Furthermore, the battery 18 may not be a component of the main body 2 or the tubular belt sander 1, but rather a component separate from the main body 2 or the tubular belt sander 1. Additionally, the spindle 30 may be a component of the power transmission unit 28. The spindle 30 may also not be a component of the output unit. The output unit may simply be the drive wheel 32, a component of accessory 4. The drive wheel 32 may also be a component of the main body 2.

[0063] The outer shell 10 forms the outer contour of the main body 2.

[0064] The housing 10 directly or indirectly holds various components.

[0065] The housing 10 includes: a motor housing 40, a fan housing 42, and a gear housing 44.

[0066] The motor housing 40 is made of plastic. The motor housing 40 is split in half, comprising a left motor housing and a right motor housing. The left and right motor housings are joined together by screws in the left-right direction (not shown).

[0067] The motor housing 40 is cylindrical. The front end of the motor housing 40 is a front opening facing forward. The rear end of the motor housing 40 is a rear opening facing backward.

[0068] The central part of the motor housing 40 in the front-rear direction is a handle G that can be held by the user.

[0069] The fan housing 42 is made of die-cast aluminum alloy. The fan housing 42 is annular. The fan housing 42 has openings on the front and rear sides.

[0070] The gear housing 44 is made of die-cast aluminum alloy. The gear housing 44 is a bell-shaped component with a reduced diameter at the front relative to the rear. The rear end of the gear housing 44 is open to the rear.

[0071] The gear housing 44 is secured to the motor housing 40 via the fan housing 42. The rear opening of the fan housing 42 mates with the front opening of the motor housing 40. The rear opening of the gear housing 44 mates with the front opening of the fan housing 42. The gear housing 44 and the fan housing 42 are secured by a plurality of (4) screws 48 extending along the front and rear. The screws 48 are located at the upper right, lower right, upper left, and lower left of the rear of the fan housing 42 and the gear housing 44. Each screw 48 enters from the front to the rear.

[0072] Furthermore, the housing 10 can be modified in various ways. For example, in the motor housing 40, the front and rear parts can be configured as separate units that can be combined with each other. Additionally, in the split motor housing 40, the left and right motor housings can be configured such that at least one of their sizes and shapes is significantly different. Furthermore, the left and right motor housings can be combined using locking parts such as claws and locking parts such as claw holes, instead of screws. The gear housing 44 can be configured as a split unit. The fan housing 42 can be omitted by integrating it with either the motor housing 40 or the gear housing 44. The materials of various parts within the housing 10 can be changed.

[0073] Motor 12 is a brushless motor and a DC motor. Motor 12 is the driving source for drive wheel 32.

[0074] The motor 12 has: a motor shaft 50 and a pinion 52.

[0075] The motor shaft 50 rotates about its own central axis. The motor shaft 50 extends back and forth.

[0076] The pinion 52 is integrally fixed to the front end of the motor shaft 50.

[0077] The fan 14 and the motor shaft 50 are fixed together.

[0078] Fan 14 is a centrifugal fan. Alternatively, other fans, such as axial fans, can also be used as fan 14.

[0079] The battery assembly section 16 is located at the rear end of the main body section 2. The battery assembly section 16 extends vertically and horizontally relative to the front portion.

[0080] A battery 18 is mounted in the battery assembly section 16. The battery assembly section 16 has a main body side terminal that is connected to the terminals of the battery 18. The main body side terminal is disposed within the rear opening of the main body section 2.

[0081] The battery 18 is mounted at the rear of the battery mounting section 16. The battery 18 is mounted by sliding downwards from the upper side of the battery mounting section 16. Furthermore, the sliding mounting direction of the battery 18 can be any direction other than downwards. Additionally, the battery 18 can be mounted in a manner other than sliding.

[0082] The storage battery 18 is a 36V lithium-ion battery. The storage battery 18 consists of 10 individual cells (not shown) housed within a plastic battery casing. Each cell is a cylindrical shape that is elongated in the axial direction and faces left-right when the storage battery 18 is assembled. The storage battery 18 provides power for driving the motor 12. Furthermore, any lithium-ion battery of 10.8V, 14.4V, 18V, 25.2V, or 28V can be used as the storage battery 18. Additionally, lithium-ion batteries with voltages less than 10.8V or greater than 36V can be used as the storage battery 18. Other types of batteries can also be used as the storage battery 18. Multiple storage batteries 18 can also be used.

[0083] The controller 20 is held inside the battery assembly 16.

[0084] The controller 20 controls the motor 12. The motor 12 is electrically connected to the controller 20 via connector 22. In addition, the main body side terminals of the battery assembly 16 are electrically connected to the controller 20.

[0085] In addition, the speed adjustment dial 24 and the main switch 26 are electrically connected to the controller 20.

[0086] Connector 22 is clamped onto the wire that connects motor 12 and controller 20 (not shown).

[0087] Connector 22 can be disconnected in a reconnectable manner. If only one of the motor 12 and controller 20 needs to be replaced due to failure or other reasons, the replacement can be easily carried out by disconnecting connector 22.

[0088] The speed adjustment dial 24 is located on the upper part of the rear end of the motor housing 40.

[0089] The speed adjustment dial 24 extends in the up, down, left, and right directions and can rotate around an imaginary axis in the front-back direction.

[0090] The upper part of the speed adjustment dial 24 is exposed.

[0091] The main switch 26 is located on the upper front end of the motor housing 40.

[0092] The upper part of the main switch 26 is exposed. The main switch 26 can slide from the rear open position to the front maximum closed position along the front-back direction.

[0093] When the user slides the main switch 26 from the off position toward the front, after passing through the specified clearance, the main switch 26 will turn on.

[0094] Furthermore, when the main switch 26 is further moved forward from the ON state, the state of the emitted signal can be changed according to the amount of forward movement. In this case, the speed adjustment dial 24 can be omitted, and the controller 20 can change the rotational speed of the motor 12 according to the state of the signal from the main switch 26. The controller 20 can control the motor 12 so that the more the main switch 26 is moved forward, the faster the rotational speed of the motor 12 becomes. Alternatively, the clearance can be omitted, and the main switch 26 can be immediately turned ON upon initiation of forward movement.

[0095] The power transmission unit 28 transmits the power of the motor 12 to the drive wheel 32 via the main shaft 30. The main shaft 30 is cylindrical and extends left and right.

[0096] The power transmission unit 28 has a bevel gear (not shown).

[0097] The bevel gear meshes with the pinion section 52.

[0098] The bevel gear reduces the rotation of the motor shaft 50 and transmits it to the main shaft 30.

[0099] Annex 4 includes: a drive wheel 32, a base portion 100, a base portion cover 101, a first joint portion 102, a base end arm 104 as an arm connector, a base end arm cover 105, a first driven wheel 106, a second joint portion 108, an end arm 110 as an arm, an end arm cover 111, a second driven wheel 114, and a handle 116.

[0100] The drive wheel 32 is cylindrical, extending to the left and right.

[0101] The left end of the main shaft 30 enters the center of the right side of the drive wheel 32. The drive wheel 32 and the main shaft 30 are fixed together. The rotation of the main shaft 30 is transmitted to the drive wheel 32. The drive wheel 32 rotates around its own central axis.

[0102] The drive wheel 32 receives the sanding belt B. The sanding belt B is detachably mounted on the drive wheel 32. The drive wheel 32 is a component for mounting the sanding belt B in a drivable manner.

[0103] The base portion 100 is made of metal, more specifically, of a die-cast aluminum alloy. The base portion 100 has a fixing portion 120 and a bearing portion 122.

[0104] The fixing part 120 is integrally fixed to the front left side of the gear housing 44 by a screw (not shown) in a left-right direction. Accordingly, the accessory 4, other than the drive wheel 32, is assembled to the main body 2. The screw enters from the left side towards the right. The fixing part 120 is adjacent to the drive wheel 32.

[0105] The bearing portion 122 is positioned above the fixing portion 120. The bearing portion 122 is biplane and has a left protrusion that protrudes upwards from the left side in a plate-like shape, and a right protrusion that protrudes upwards from the right side in a plate-like shape. The left protrusion has a central hole. The right protrusion has a central hole.

[0106] The base portion cover 101 is made of metal, more specifically steel. The base portion cover 101 is in the shape of a folded plate. The base portion cover 101 is mounted on the base portion 100.

[0107] The base cover 101 covers the rear side of the portion of the sanding belt B that is attached to the drive wheel 32. That is, the base cover 101 covers the sanding belt B on the user side.

[0108] The first joint portion 102 includes: a shaft 130, a torsion spring (not shown) serving as a base-end elastic body, and a spring ring 134. Furthermore, the torsion spring may not be a component of the first joint portion 102, but may be a separate component.

[0109] The shaft 130 is cylindrical and extends to the left and right.

[0110] A torsion spring is disposed around the shaft 130. The torsion spring is clamped between the base portion 100 and the base end arm 104. The torsion spring applies force to the base end arm 104 to make it oriented in the vertical direction. That is, the torsion spring applies force to the base end arm 104 in the rotational direction from the horizontal position to the vertical position.

[0111] The spring ring 134 is located at the left end of the shaft 130.

[0112] The first joint 102 rotatably connects the base end arm 104 to the base portion 100. The base end arm 104 is rotatably connected to the base portion 100.

[0113] The base end arm 104 is made of metal, more specifically, of a die-cast aluminum alloy. The base end arm 104 is arc-shaped, extending vertically. The base end arm 104 is warped in a rearward convex manner. The base end arm 104 is positioned closer to the main body 2 than the end arm 110, i.e., at the base end position.

[0114] The base end arm 104 has: a lower bearing portion (not shown), a first driven wheel retaining portion (not shown), and an upper bearing portion 146.

[0115] The lower bearing portion is located at the lower end of the base end side arm 104.

[0116] The lower bearing portion is bifurcated and has a left protrusion that protrudes downwards from the left side in a plate-like shape, and a right protrusion that protrudes downwards from the right side in a plate-like shape. The left protrusion has a central hole. The right protrusion has a central hole.

[0117] The left protrusion of the lower bearing portion is positioned to the right of the left protrusion of the base portion 100. The right protrusion of the lower bearing portion is positioned to the left of the right protrusion of the base portion 100. The central holes of the left and right protrusions of the lower bearing portion, the left and right protrusions of the base portion 100, and the right protrusion of the base portion 100 are arranged horizontally and receive the shaft 130 of the first joint portion 102. The base end arm 104 is rotatable relative to the base portion 100 about the shaft 130. Accordingly, Annex 4 has a first joint.

[0118] The shaft 130 is prevented from falling off by a spring ring 134 on the left side of the left protrusion. The torsion spring is positioned between the left protrusion of the lower bearing portion and the right protrusion of the lower bearing portion.

[0119] The first driven wheel retaining part is a hole in the left and right direction and the part around it, and is disposed on the upper part of the base end side arm 104.

[0120] The upper bearing portion 146 is disposed at the upper end of the base end side arm 104.

[0121] The upper bearing portion 146 is symmetrical to the lower bearing portion. That is, the upper bearing portion 146 is in the form of two protrusions and has a left protrusion 146L that protrudes upward from the left side in a plate-like shape, and a right protrusion 146R that protrudes upward from the right side in a plate-like shape. The left protrusion 146L has a central hole. The right protrusion 146R has a central hole.

[0122] Furthermore, the upper bearing portion 146 may not be symmetrical with the lower bearing portion.

[0123] The base-end arm belt cover 105 is made of metal, more specifically steel. The base-end arm belt cover 105 is folded plate shaped. The base-end arm belt cover 105 is mounted to the base-end arm 104 by a plurality of (2) left-right oriented screws 148.

[0124] The base-end arm belt cover 105 covers the upper and rear sides of the portion of the sanding belt B that is hooked onto the first driven wheel 106, as well as the rear side of the portion of the sanding belt B that is mounted between the first driven wheel 106 and the drive wheel 32. That is, the base-end arm belt cover 105 covers the sanding belt B on the user side.

[0125] The first driven wheel 106 includes: a first driven wheel shaft 150, a first driven wheel rotating part 152, and multiple bearings 154. Figure 5 ), and spring ring 158.

[0126] The first driven wheel shaft 150 is a cylindrical pin extending from left to right. The first driven wheel shaft 150 is integrally fixed to the hole of the first driven wheel retaining part.

[0127] The first driven wheel rotating part 152 is in the shape of a cylinder and has an inner hole extending along the left and right sides.

[0128] Each bearing 154 is held on the first driven wheel shaft 150. Each bearing supports the first driven wheel rotating part 152 so that it can rotate.

[0129] A spring ring 158 is disposed at the left end of the first driven wheel shaft 150. The rotating part 152 of the first driven wheel is prevented from falling off by the spring ring 158.

[0130] The first driven wheel 106 is held on the base end side arm 104.

[0131] The first driven wheel 106 receives the sanding belt B. The sanding belt B is detachably mounted to the first driven wheel 106. The first driven wheel 106 is a driven wheel driven by the driven sanding belt B. The first driven wheel 106 is used for mounting the sanding belt B.

[0132] The second joint 108 includes: a shaft 160, a torsion spring 162 as an end-side elastic body, and a spring ring 164. Furthermore, the torsion spring 162 may not be a component of the second joint 108, but may be a separate component.

[0133] The shaft 160 is cylindrical and extends to the left and right.

[0134] A torsion spring 162 is disposed around the shaft 160. The torsion spring 162 is clamped between the base side arm 104 and the end side arm 110. The torsion spring 162 applies force to the end side arm 110 to open it forward and upward relative to the base side arm 104. That is, the torsion spring 162 can apply force to the end side arm 110 in a rotational direction that opens it further relative to the base side arm 104.

[0135] The spring ring 164 is located at the left end of the shaft 160.

[0136] The second joint 108 rotatably connects the end side arm 110 to the base side arm 104.

[0137] The end side arm 110 is made of metal, more specifically, of die-cast aluminum alloy. The end side arm 110 extends along the front and rear. The end side arm 110 is shaped along three sides excluding the lower base of the trapezoid. The end side arm 110 is formed into two strands with its rear end as the base, extending along the front and top. The end side arm 110 protrudes upwards. The end side arm 110 is positioned further away from the main body 2 than the base side arm 104, i.e., at the end side position.

[0138] The end arm 110 has: a rear bearing portion 170, a second driven wheel retaining portion (not shown), and a handle mounting portion 174.

[0139] The rear bearing portion 170 is located at the rear end of the end side arm 110.

[0140] The rear bearing portion 170 is bifurcated and has a left protrusion 170L that protrudes downward from the left side in a plate-like shape, and a right protrusion 170R that protrudes downward from the right side in a plate-like shape. The left protrusion 170L has a central hole. The right protrusion 170R has a central hole.

[0141] The left protrusion 170L is positioned to the left of the left protrusion 146L of the upper bearing portion 146 of the base end side arm 104. The right protrusion 170R is positioned to the right of the right protrusion 146R of the upper bearing portion 146 of the base end side arm 104. The central holes of the left protrusion 170L, the left protrusion 146L, the right protrusion 146R, and the right protrusion 170R are arranged horizontally and receive the shaft 160 of the second joint portion 108. The end side arm 110 is rotatable relative to the base end side arm 104 about the shaft 160. Accordingly, Annex 4 has a second joint.

[0142] The shaft 160 is prevented from falling off by a spring ring 164 on the left side of the left protrusion 170L. The torsion spring 162 is positioned between the left protrusion 146L and the right protrusion 146R of the upper bearing portion 146.

[0143] The second driven wheel retaining part is a hole in the left and right direction and the part around it, and is disposed at the front end of the end arm 110.

[0144] The handle mounting portion 174 is a hole in the left and right direction and the portion around it, and is configured at the upper end of the portion of the end arm 110 that extends upward.

[0145] The end arm belt cover 111 is made of metal, more specifically steel. The end arm belt cover 111 is folded plate shaped. The end arm belt cover 111 is mounted to the end arm 110 by a plurality of (2) left-right screws 178.

[0146] The end-side arm belt cover 111 covers the upper side of the portion of the sanding belt B that is positioned between the second driven pulley 114 and the first driven pulley 106. That is, the end-side arm belt cover 111 covers the sanding belt B on the user side.

[0147] The second driven wheel 114 includes: a second driven wheel shaft 180, a second driven wheel rotating part 182, and multiple (2) bearings 184. Figure 6 ), and spring ring 188.

[0148] The second driven wheel shaft 180 is a cylindrical pin extending from left to right. The second driven wheel shaft 180 is integrally fixed to the hole of the second driven wheel retaining part.

[0149] The second driven wheel rotating part 182 is in the shape of a cylinder and has an inner hole extending along the left and right sides.

[0150] Each bearing 184 is held on the second driven wheel shaft 180. Each bearing 184 supports the rotating part 182 of the second driven wheel so that it can rotate.

[0151] A spring ring 188 is disposed at the left end of the second driven wheel shaft 180. The rotating part 182 of the second driven wheel is prevented from falling off by the spring ring 188.

[0152] The second driven wheel 114 is held at the end side arm 110.

[0153] The second driven wheel 114 receives the sanding belt B. The sanding belt B is detachably mounted to the second driven wheel 114. The second driven wheel 114 is a driven wheel driven by the driven sanding belt B. The second driven wheel 114 is used for mounting the sanding belt B.

[0154] Abrasive belt B is in the form of a strip or ring, that is, a seamless sandpaper. Abrasive belt B has a surface for grinding the workpiece, that is, a grinding surface.

[0155] A sanding belt B is mounted on the drive wheel 32, the first driven wheel 106, and the second driven wheel 114 with the grinding surface facing outwards. When not grinding, viewed from the left, the sanding belt B has a triangular shape with the drive wheel 32, the first driven wheel 106, and the second driven wheel 114 as vertices.

[0156] The abrasive belt B receives driving force from the drive wheel 32 and is conveyed at a speed corresponding to the rotational position of the speed adjustment dial 24. In the tubular belt sander 1, the conveying speed of the abrasive belt B, i.e., the belt speed, can be 8 m / s or less. Furthermore, the minimum belt speed can be 3.4 m / s or less. For example, when the rotational position of the speed adjustment dial 24 is operated to the position corresponding to the minimum belt speed, the belt speed is set to 3.1 m / s.

[0157] A tubular belt sander 1 with a belt speed set to 8 m / s or less is used, for example, for grinding tubular parts of indoor structures, such as railings. Additionally, a tubular belt sander 1 with a belt speed set to 8 m / s or less is used, for example, for mirror polishing.

[0158] The handle 116 extends to the left and right and can be gripped by the user.

[0159] The handle 116 is integrally fixed to the handle mounting portion 174 of the end arm 110. The handle 116 is positioned on the left side of the handle mounting portion 174.

[0160] The drive wheel 32, the first driven wheel 106, the second driven wheel 114, the end side arm 110, and the base side arm 104 are elements of the working part structure P, which are used to fold the attachment 4, which is the working part.

[0161] In addition, elements other than those mentioned above can be added to the work unit structure P. Alternatively, some of the aforementioned elements can be omitted from the work unit structure P.

[0162] Figure 3 This is a 3D view of drive wheel 32. Figure 4 It is a cross-sectional view of the drive wheel 32, which passes through the center in the front-rear direction and extends in the up, down, left, and right directions.

[0163] The drive wheel 32 has an inner wheel portion 200, an outer wheel portion 202, and a guide portion 204.

[0164] The inner wheel portion 200 is made of metal, more specifically, of aluminum alloy. The inner wheel portion 200 is cylindrical. The inner wheel portion 200 extends to the left and right.

[0165] The inner wheel portion 200 has an inner wheel bore 210. The inner wheel bore 210 is cylindrical and extends laterally. The end portion of the main shaft 30 enters the inner wheel bore 210.

[0166] The outer ring portion 202 is made of synthetic resin, more specifically, of polyamide. The outer ring portion 202 is tubular. The outer ring portion 202 extends laterally. Because it is made of polyamide, the outer ring portion 202 exhibits chemical resistance. Therefore, it can suppress the deterioration of the outer ring portion 202 caused by dust from coating components generated during the peel coating process. Furthermore, the outer ring portion 202 may or may not contain fibers such as glass fiber.

[0167] The outer wheel portion 202 has: an outer wheel portion body 220, an outer wheel inner hole 221, a plurality of (2) drive wheel flange portions 222, and a plurality of ribs 224.

[0168] The outer wheel body 220 is cylindrical and extends to the left and right.

[0169] The inner hole 221 of the outer wheel is formed at the center of the outer wheel body 220 in the radial direction.

[0170] The inner bore 221 of the outer wheel is cylindrical and extends to the left and right. The size of the inner bore 221 of the outer wheel is the same as or approximately the same as the size of the inner wheel portion 200.

[0171] The inner wheel portion 200 enters the inner hole 221 of the outer wheel. The inner wheel portion 200 is fixed to the inner hole 221 of the outer wheel.

[0172] Each drive wheel flange 222 is flange-shaped and protrudes radially outward from the left-right end of the outer wheel body 220. Each drive wheel flange 222 appears annular when viewed from the side.

[0173] The drive wheel flange portion 222 includes a left drive wheel flange portion 222L and a right drive wheel flange portion 222R. The left drive wheel flange portion 222L is located at the outer side of the left end of the outer wheel portion body 220. The right drive wheel flange portion 222R is located at the outer side of the right end of the outer wheel portion body 220.

[0174] The protrusion height of the left drive wheel flange 222L is the same as the protrusion height of the right drive wheel flange 222R.

[0175] Furthermore, the protrusion height of the left drive wheel flange portion 222L may be less than or greater than the protrusion height of the right drive wheel flange portion 222R. Additionally, at least one of the left drive wheel flange portion 222L and the right drive wheel flange portion 222R may be separate from the outer wheel portion 202.

[0176] Each rib 224 is positioned in the left-right direction between the flange portions 222 of each drive wheel.

[0177] Each rib 224 protrudes radially outward from the outer surface of the outer wheel body 220.

[0178] The guide portion 204 and the outer wheel portion 202 are integrally formed. In addition, the outer wheel portion 202 and the guide portion 204 can be fixed to each other by means other than integral forming.

[0179] The guide portion 204 is made of rubber and is cylindrical. The guide portion 204 is an elastomer. The guide portion 204 extends to the left and right.

[0180] The guide portion 204 is positioned on the right side, i.e., axially inner side, of the left drive wheel flange 222L. The guide portion 204 is also positioned on the left side, i.e., axially inner side, of the right drive wheel flange 222R. Finally, the guide portion 204 is positioned between the flanges of each drive wheel 222.

[0181] The guide section 204 includes: a guide section body 230, a guide section inner hole 232, and a rib 234.

[0182] The main body 230 with the guide section is cylindrical and extends to the left and right.

[0183] The outer surface of the guide body 230 is a drive wheel belt contact portion TD that can contact the abrasive belt B. The drive wheel belt contact portion TD bulges outward in a radial direction. The drive wheel belt contact portion TD is centered at M in the left-right direction. Figure 4 It descends slowly to both sides from its apex. This bulging shape is called the "crown". This bulging shape can suppress the outward deviation of the sand belt B from the central part M of the drive wheel belt contact part TD in the left and right directions.

[0184] The inner surface of the abrasive belt B comes into contact with the drive wheel belt contact portion TD. The belt guide body 230 conveys the abrasive belt B.

[0185] Each drive wheel flange 222 is adjacent to the drive wheel belt contact portion TD. Each drive wheel flange 222 is positioned on both sides of the drive wheel belt contact portion TD. Each drive wheel flange 222 is positioned on both sides in the width direction of the drive wheel belt contact portion TD. Each drive wheel flange 222 is positioned on both sides in the width direction of the sanding belt B.

[0186] The guide hole 232 is formed in the central part of the radial direction of the guide body 230.

[0187] The guide portion inner hole 232 is cylindrical and extends to the left and right. The size of the guide portion inner hole 232 is the same as or approximately the same as the size of the portion of each drive wheel flange 222 that is further inward in the left and right direction compared to the outer wheel portion 202.

[0188] The outer wheel portion 202 enters the inner hole 232 of the belt guide portion. The outer wheel portion 202 is fixed in the inner hole 232 of the belt guide portion.

[0189] Each rib 234 protrudes radially inward from the inner surface of the inner hole 232 of the guide section.

[0190] Each rib 234 is integrally formed to engage with each rib 224 of the outer wheel portion 202 without gap.

[0191] like Figure 4 As shown, the imaginary central axis ND of the drive wheel 32 extending left and right coincides with, or is substantially coincident with, the imaginary central axis of the inner wheel portion 200, the imaginary central axis of the outer wheel portion 202, and the imaginary central axis with the guide portion 204.

[0192] The distance between the central axis ND and the central part M of the drive wheel belt contact portion TD is equivalent to: the radius a of the drive wheel belt contact portion. D The central part M of the drive wheel belt contact portion TD is the part located furthest outward in the radial direction among the parts that contact the sand belt B.

[0193] The distance between the central axis ND and the end of the left drive wheel flange 222L is equivalent to: the radius b of the left drive wheel flange. DL .

[0194] The distance between the left surface (i.e., the inner surface in the left-right direction) of the right drive wheel flange 222R and the right surface (i.e., the inner surface in the left-right direction) of the left drive wheel flange 222L is equivalent to: the drive wheel flange interval c D .

[0195] Furthermore, the radius b of the left drive wheel flange DL relative to the radius a of the drive wheel contact part D proportion (b) DL / a D () can be 1.1 or higher. b DL / a D Corresponding to: the relative height of the left drive wheel flange portion 222L. In this case, the left drive wheel flange portion 222L can fully exert its effect in suppressing the shedding of the sand belt B.

[0196] In addition, b DL / a D It can also be 1.2 or higher. In this case, the left drive wheel flange 222L can more fully exert its effect in suppressing the shedding of the sand belt B.

[0197] For example, the radius a of the drive wheel belt contact portion D The radius of the left drive wheel flange is 30mm. DL It is 38.5mm. In this case, b DL / a D For (b) DL / a D =1.28, which can more effectively suppress the shedding of sand belt B toward the opposite side of the main body 2.

[0198] In addition, the radius b of the left drive wheel flange DL Subtract the radius a of the drive wheel contact section D And a difference is obtained, this difference (b) DL -a D Divide by the distance c between the drive wheel flanges D The obtained value, that is, (b) DL -a D ) / c DIt can be above 0.05. DL -a D Corresponding to: the height of the left drive wheel flange 222L. In this case, it is possible to obtain a height of the left drive wheel flange 222L that corresponds to the width of the drive wheel 32, so that the left drive wheel flange 222L can fully exert its effect on suppressing the shedding of the sand belt B.

[0199] For example, consider the following case: That is, the radius 'a' of the drive wheel's contact area. D The radius b of the left drive wheel flange is 30mm. DL It is 38.5mm. The drive wheel flange spacing is c. D It is 45mm. In this case, (b) DL -a D ) / c D For: ((b) DL -a D ) / c D ) = 0.189. Thus, (b DL -a D ) / c D The value is: 0.05≤((b) DL -a D ) / c D Therefore, it can more effectively suppress the shedding of sand belt B toward the opposite side of the main body 2.

[0200] Additionally, (b) DL -a D ) / c D It can also be below 1.00. In this case, the effect of the left drive wheel flange 222L in suppressing the detachment of the sanding belt B can be fully obtained, and the reduction in workability caused by the replacement of the sanding belt B can be fully suppressed.

[0201] For example, consider the following case, which differs from the above: That is, the radius a of the drive wheel contact area... D The radius b of the left drive wheel flange is 30mm. DL It is 38.5mm. The drive wheel flange spacing is c. D It is 9mm narrower than the case described above. In this case, (b) DL -a D ) / c D For: ((b) DL -a D ) / c D ) = 0.94. Thus, (b DL -a D ) / c D For: ((b) DL -a D ) / c D)≤1.00, therefore, it can effectively suppress the decrease in workability caused by the replacement of sand belt B.

[0202] In addition, (b) DL -a D That is, the height of the left drive wheel flange 222L can also be 3mm or more. In this case, the effect of the left drive wheel flange 222L in suppressing the shedding of the sand belt B can be fully achieved.

[0203] Furthermore, regarding the right drive wheel flange 222R, the radius b of the right drive wheel flange can also be determined. DR The radius b of the right drive wheel flange. DR This can be the distance between the end of the right drive wheel flange 222R and the central axis ND. (b) DR / a D (b) can be 1.1 or higher, or 1.2 or higher. DR -a D ) / c D It can be above 0.05 or below 1.00. (b) DR -a D That is, the height of the right drive wheel flange 222R can be 3mm or more. The radius b of the drive wheel flange... D It can be used as the radius b of the left drive wheel flange. DL and the radius b of the right drive wheel flange DR At least one party must have control over it.

[0204] Figure 5 It is a cross-sectional view of the first driven wheel 106, which passes through the center in the front-rear direction and extends in the up, down, left and right directions.

[0205] The first driven wheel 106 has a first driven wheel rotating part 152 having a plurality of (2) first driven wheel flanges 153.

[0206] Each first driven wheel flange 153 protrudes radially outward from its end in the left-right direction of the first driven wheel rotating part 152. Each first driven wheel flange 153 is annular when viewed from the side.

[0207] The first driven wheel flange portion 153 includes a left first driven wheel flange portion 153L and a right first driven wheel flange portion 153R. The left first driven wheel flange portion 153L is disposed at the left end of the first driven wheel rotating portion 152. The right first driven wheel flange portion 153R is disposed at the right end of the first driven wheel rotating portion 152.

[0208] The protrusion height of the flange portion 153L of the left first driven wheel is the same as or approximately the same as the protrusion height of the flange portion 153R of the right first driven wheel.

[0209] Furthermore, the protrusion height of the left first driven wheel flange 153L may be less than or greater than the protrusion height of the right first driven wheel flange 153R. Additionally, at least one of the left first driven wheel flange 153L and the right first driven wheel flange 153R may be separate from the first driven wheel rotating part 152.

[0210] In addition, multiple ribs 155 stand between the first driven wheel flange portion 153 of the first driven wheel rotating portion 152. Each rib 155 protrudes in a ring shape toward the radially outward.

[0211] The end face of each rib 155 is: the first driven pulley belt contact part T1 that can contact the sand belt B.

[0212] Each first driven pulley flange 153 is adjacent to the first driven pulley belt contact portion T1. Each first driven pulley flange 153 is positioned on both sides of the first driven pulley belt contact portion T1. Each first driven pulley flange 153 is positioned on both sides of the first driven pulley belt contact portion T1 in the width direction. Each first driven pulley flange 153 is positioned on both sides of the sanding belt B in the width direction.

[0213] like Figure 5 As shown, the imaginary central axis of the first driven wheel rotating part 152 extending left and right, that is, the central axis N1 of the first driven wheel, coincides with or is approximately coincident with the imaginary central axis of each bearing 154.

[0214] The distance between the central shaft N1 of the first driven wheel and the contact part T1 of the first driven wheel belt is equivalent to the radius a1 of the contact part of the first driven wheel belt.

[0215] The distance between the central shaft N1 of the first driven wheel and the end of the flange portion 153L of the left first driven wheel or the flange portion 153R of the right first driven wheel is equivalent to the radius b1 of the flange portion of the first driven wheel.

[0216] Figure 6 It is a cross-sectional view of the second driven wheel 114, which passes through the center in the front-rear direction and extends in the up, down, left and right directions.

[0217] The second driven wheel rotating part 182 of the second driven wheel 114 has: a plurality of (2) second driven wheel flanges 183.

[0218] Each second driven wheel flange 183 protrudes radially outward from its end in the left-right direction of the second driven wheel rotating part 182. Each second driven wheel flange 183 is annular when viewed from the side.

[0219] The second driven wheel flange 183 includes a left second driven wheel flange 183L and a right second driven wheel flange 183R. The left second driven wheel flange 183L is disposed at the left end of the second driven wheel rotating part 182. The right second driven wheel flange 183R is disposed at the right end of the second driven wheel rotating part 182.

[0220] The protrusion height of the flange portion 183L of the left second driven wheel is the same as or approximately the same as the protrusion height of the flange portion 183R of the right second driven wheel.

[0221] Furthermore, the protrusion height of the left second driven wheel flange 183L can be less than or greater than the protrusion height of the right second driven wheel flange 183R. Additionally, at least one of the left second driven wheel flange 183L and the right second driven wheel flange 183R can be separate from the second driven wheel rotating part 182.

[0222] In addition, multiple ribs 185 stand between the flange portions 183 of the second driven wheel in the rotating portion 182 of the second driven wheel. Each rib 185 protrudes in a ring shape toward the radially outward.

[0223] The end face of each rib 185 is: the second driven pulley belt contact part T2, which can contact the sand belt B.

[0224] Each second driven wheel flange 183 is adjacent to the second driven wheel belt contact portion T2. ​​Each second driven wheel flange 183 is positioned on both sides of the second driven wheel belt contact portion T2. ​​Each second driven wheel flange 183 is positioned on both sides of the second driven wheel belt contact portion T2 in the width direction. Each second driven wheel flange 183 is positioned on both sides of the sanding belt B in the width direction.

[0225] like Figure 6 As shown, the imaginary central axis of the second driven wheel rotating part 182 extending left and right, and the central axis N2 of the second driven wheel, are consistent with or substantially consistent with the imaginary central axis of each bearing 184.

[0226] The distance between the central shaft N2 of the second driven wheel and the contact part T2 of the second driven wheel belt is equivalent to the radius a2 of the contact part of the second driven wheel belt.

[0227] The distance between the central shaft N2 of the second driven wheel and the end of the flange 183L of the left second driven wheel or the flange 183R of the right second driven wheel is equivalent to the radius b2 of the flange of the second driven wheel.

[0228] Furthermore, the tubular belt sander 1 can be configured, for example, as follows: the drive wheel 32 b D / a DOne of b1 / a1 of the first driven wheel 106 and b2 / a2 of the second driven wheel 114 is greater than 1.2, and the remaining two are less than 1.2.

[0229] In this case, the shedding suppression effect of abrasive belt B can be fully obtained, and the replacement of abrasive belt B becomes easier.

[0230] The structure of the working section of the belt grinder, which includes this case, is disclosed below.

[0231] (1) A working section structure for a belt sander, characterized in that, it is a working section of a belt sander for performing operations on a workpiece, and is described as follows:

[0232] The working part of the belt sander includes three or more wheels for assembling one sanding belt.

[0233] Each of the aforementioned wheels has: a belt contact portion that contacts the sanding belt, and flange portions disposed on both sides of the belt contact portion.

[0234] The ratio (b / a) of the distance from the end of the flange to the central axis of any one of the wheels, i.e., the wheel radius (b), to the distance from the belt contact portion to the central axis of the wheel, i.e., the belt contact portion radius (a), is 1.2 or more.

[0235] In the other two or more wheels, the ratio (b / a) of the distance from the end of the flange to the central axis, i.e., the wheel radius (b), to the distance from the belt contact portion to the central axis of the wheel, i.e., the belt contact portion radius (a), is less than 1.2.

[0236] Additionally, the tubular belt sander 1 can be configured, for example, as follows: the drive wheel 32 b D / a D The ratio is greater than or equal to 1.2, the ratio of b1 / a1 of the first driven wheel 106 is less than 1.2, and the ratio of b2 / a2 of the second driven wheel 114 is less than 1.2.

[0237] In this case, the shedding suppression effect of abrasive belt B can be fully obtained, and the replacement of abrasive belt B becomes easier.

[0238] The structure of the working section of the belt grinder, which includes this case, is disclosed below.

[0239] (2) A working section structure for a belt sander, characterized in that, it is a working section in a belt sander for performing operations on a workpiece, and is described as follows:

[0240] The working part of the belt grinder includes a drive wheel, a first driven wheel, and a second driven wheel, which are used to assemble one sanding belt.

[0241] The drive wheel has: a drive wheel belt contact portion that contacts the sanding belt, and drive wheel flange portions disposed on both sides of the drive wheel belt contact portion.

[0242] The first driven wheel has: a first driven wheel belt contact portion that contacts the sanding belt, and a first driven wheel flange portion disposed on both sides of the first driven wheel belt contact portion.

[0243] The second driven wheel has: a second driven wheel belt contact portion that contacts the sanding belt, and second driven wheel flange portions disposed on both sides of the second driven wheel belt contact portion.

[0244] The distance from the end of the drive wheel flange to the central axis in the drive wheel is also known as the drive wheel radius (b). D The distance from the drive wheel belt contact portion to the central axis of the drive wheel, i.e., the radius of the drive wheel belt contact portion (a) D The proportion of (b) D / a D The value is 1.2 or higher.

[0245] The distance from the end of the flange of the first driven wheel to the central axis, i.e., the radius (b1) of the first driven wheel, relative to the distance from the contact portion of the first driven wheel to the central axis, i.e., the radius (a1) of the contact portion, is less than 1.2.

[0246] The distance from the end of the flange of the second driven wheel to the central axis, i.e., the radius (b2) of the second driven wheel, is less than 1.2 relative to the distance from the contact portion of the second driven wheel to the central axis of the second driven wheel, i.e., the radius (a2) of the contact portion of the second driven wheel.

[0247] The operation of such a tubular belt sander 1, accessory 4, and working part structure P is explained.

[0248] The user assembles the fully charged battery 18 into the battery assembly section 16 of the main body 2. The user assembles accessory 4 into the main body 2. The user locks accessory 4 in place. The user assembles sanding belt B into accessory 4.

[0249] When the user operates the main switch 26, the main switch 26 is turned on. The controller 20 then supplies power from the battery 18 to the motor 12, causing the motor shaft 50 to rotate at a speed corresponding to the rotational position of the speed adjustment dial 24. Accordingly, the motor 12 is driven at a speed corresponding to the rotational position of the speed adjustment dial 24. Furthermore, the rotation direction of the motor shaft 50 can be configured to be switchable.

[0250] The fan 14 rotates due to the rotation of the motor shaft 50, and an airflow (wind) is formed in the main body 2 by exhausting air towards the exhaust port (not shown).

[0251] This airflow cools the internal mechanisms of the grinding machine 1, represented by motor 12.

[0252] Furthermore, the rotational force of the motor shaft 50 is transmitted to the main shaft 30 and the drive wheel 32 via a reduction at the bevel gear.

[0253] The drive wheel 32 conveys the sanding belt B. The sanding belt B rotates in an infinite track shape outside the drive wheel 32, the first driven wheel 106, and the second driven wheel 114.

[0254] The belt speed can be adjusted to 8 m / s or less using the speed adjustment dial 24. Alternatively, the belt speed can be adjusted to 3.4 m / s or less using the speed adjustment dial 24. Furthermore, the belt speed can be set to 8 m / s or less regardless of the rotational position of the speed adjustment dial 24, i.e., the operating state of the speed adjustment dial 24. Alternatively, the speed adjustment dial 24 can be omitted, thus ensuring the belt speed is always at a predetermined value of 8 m / s or less. Alternatively, the speed adjustment dial 24 can be omitted, thus ensuring the belt speed is always at a predetermined value of 3.4 m / s or less.

[0255] The user holds the handle G of the main body 2 with their right hand and the handle 116 of the accessory 4 with their left hand.

[0256] Furthermore, the user brings the lower surface of the portion between the drive wheel 32 and the second driven wheel 114 in the conveyed sanding belt B, as well as the outer surface of the cylinder, and other parts of the workpiece to be processed. Thus, the processed parts of the workpiece are ground by the sanding belt B.

[0257] At this time, the path traversed by the portion between the drive wheel 32 and the second driven wheel 114 in the abrasive belt B corresponds to the pressing pressure applied to the workpiece, and when viewed from left to right, it forms a "U"-shaped indentation along the workpiece upwards. With this indentation in the path of the abrasive belt B, the path of the abrasive belt B changes from a triangular shape to a quadrilateral shape. Through this indentation in the path of the abrasive belt B, the workpiece is surrounded by the abrasive belt B. Therefore, the grinding of the workpiece can be performed more effectively.

[0258] Since the length of the abrasive belt B remains constant, the second driven wheel 114 approaches the drive wheel 32 by an amount corresponding to the concavity of the path of the abrasive belt B. The approach of the second driven wheel 114 relative to the drive wheel 32 is primarily achieved by the rotation of the end arm 110 relative to the base arm 104. This rotation of the end arm 110 relative to the base arm 104 is achieved by the torsion spring 162 in an elastic state.

[0259] Furthermore, the rotation of the base arm 104 relative to the base portion 100 is carried out in an elastic state by the torsion spring of the first joint portion 102.

[0260] The tubular belt grinder 1 is a two-joint type grinder with a first joint 102 and a second joint 108 arranged longitudinally at the front and rear, respectively, which can rotate in an elastic state. Therefore, compared with a single-joint type grinder without the first joint 102, the contact between the abrasive belt B and the workpiece is improved. Consequently, the tubular belt grinder 1 can grind the workpiece more effectively.

[0261] Next, the structure of the working section of the belt grinder involving the longitudinally arranged two-joint type will be disclosed again.

[0262] (3) A working section structure for a belt sander, characterized in that, it is a working section of a belt sander used for performing operations on a workpiece, and is described as follows:

[0263] The working part of the belt sander includes: a drive wheel and a plurality of driven wheels for assembling a sanding belt; a base portion fixed to the main body portion in an adjacent state to the drive wheel; a base end arm rotatably connected to the base portion; and an end arm rotatably connected to the base end arm and holding one or more of the driven wheels.

[0264] (4) Based on the working part structure of the belt grinder in (3), the working part structure of the belt grinder includes: an end-side elastic body that can apply force to the end-side arm relative to the base-side arm in a rotational direction; and a base-side elastic body that can apply force to the base-side arm relative to the base portion in a rotational direction.

[0265] Furthermore, during grinding, the left drive wheel flange 222L of the drive wheel 32 can suppress the abrasive belt B from falling to the left. Additionally, the right drive wheel flange 222R of the drive wheel 32 can suppress the abrasive belt B from falling to the right.

[0266] The detachment suppression effect of the abrasive belt B is fully exerted even when the belt speed is 8 m / s or less. This detachment suppression effect of the abrasive belt B is also fully exerted when the minimum settable belt speed is 3.4 m / s or less. In particular, when machining the workpiece portion that is bent relative to the abrasive belt B, the detachment of the abrasive belt B is sufficiently suppressed in the tubular belt grinder 1 compared to a tubular belt grinder with a flangeless drive wheel.

[0267] If the belt speed is slower than a specified level, the tension of the abrasive belt B becomes relatively weak, and the abrasive belt B is more likely to twist during processing, thus making it easy for the abrasive belt B to fall off. However, in the tubular belt sander 1, the falling off of the abrasive belt B can be prevented and effectively suppressed by the drive wheel flange 222.

[0268] Users can appropriately change the way the sanding belt B contacts the workpiece, that is, the position and range of the sanding belt B contacting the workpiece, according to the overall shape of the workpiece.

[0269] When grinding is complete, the user stops the forward sliding operation of the main switch 26, thus turning off the motor 12. At this time, the sanding belt B stops. The user then removes the sanding belt B, accessory 4, and battery 18 as appropriate.

[0270] Furthermore, the embodiments of the present invention are not limited to the above-described methods and modifications, and for example, the following modifications can be further appropriately implemented.

[0271] Various flange portions may only have a flange portion on the left or right side. Part or all of the flange portion of the drive wheel may also be omitted. Part or all of the flange portions of various driven wheels may also be omitted.

[0272] The drive pulley belt contact portion TD may not bulge outwards radially. For example, the drive pulley belt contact portion TD may be flat or may have a concave-convex surface formed by multiple ribs protruding outwards radially.

[0273] At least one of the end-side elastomer and the base-side elastomer can be an elastomer other than a torsion spring.

[0274] The reduction mechanism of the tubular belt sander 1, which runs from the motor shaft 50 toward the drive wheel 32, can replace the reduction mechanism other than the pinion 52 and the bevel gear.

[0275] The tubular belt sander 1 can replace the battery assembly 16 and have a power cord, thereby enabling AC drive from commercial power. The material of at least one of the various housings and outer casings can be changed to resin, metal, or composites thereof. The division of the outer casing 10 can be changed according to the above division. Furthermore, at least one of the following can be appropriately changed: the number, presence, material, configuration, structure, and form of various components and parts.

[0276] Furthermore, the above-described method or its variations can be applied to other tubular belt sanders. For example, the above-described method or its variations can also be applied to a single-joint type tubular belt sander. A single-joint type tubular belt sander can be a two-strand single-joint type sander. In the case of a two-strand single-joint type, the roots of the two strands can be configured to be folded by a switching mechanism. Alternatively, the above-described method or its variations can also be applied to: tubular belt sanders with three or more driven wheels. Alternatively, the above-described method or its variations can also be applied to: tubular belt sanders with multiple drive wheels. Alternatively, the above-described method or its variations can also be applied to: tubular belt sanders with three or more joints. Alternatively, the above-described method or its variations can also be applied to other belt sanders. Other belt sanders are, for example, file-type belt sanders.

[0277] [Method 2]

[0278] Figure 7 This is a perspective view of the drive wheel 300 of the tubular belt sander according to the second embodiment of the present invention. Figure 8 It is a cross-sectional view of the drive wheel 300, which passes through the center in the front-rear direction and extends in the up, down, left, and right directions.

[0279] Method 2 is the same as Method 1 except for the drive wheel. For the parts of Method 2 that are the same as Method 1, the same reference numerals as in Method 1 are appropriately used, and the explanations are omitted.

[0280] The second type of drive wheel 300 has an inner wheel portion 200 and an outer wheel portion 302.

[0281] The outer wheel portion 302 is made of synthetic resin, more specifically, of polyamide. The outer wheel portion 302 is tubular in shape. The outer wheel portion 302 extends to the left and right.

[0282] The outer wheel portion 302 has: an outer wheel portion body 320, an outer wheel inner hole 221, a plurality of (2) drive wheel flange portions 222, and a plurality of ribs 324.

[0283] The outer wheel body 320 is cylindrical and extends to the left and right.

[0284] Each rib 324 is positioned between the flange portions 222 of each drive wheel in the left-right direction.

[0285] Each rib 324 protrudes radially outward from the outer surface of the outer wheel body 220.

[0286] Each rib 324 appears in a ring shape when viewed from the left to the right. Ribs 324 are arranged along the left and right sides.

[0287] Unlike the first method, the outer wheel body 320 and each rib 324 are exposed to the outside.

[0288] The portion between the left and right drive wheel flanges 222 in the outer wheel portion 302 has a concave-convex shape formed by each rib 324.

[0289] The end face of each rib 324, that is, the outermost face in the radial direction, is the drive wheel belt contact part TD that contacts the sand belt B.

[0290] The sanding belt B is conveyed through the drive wheel belt contact portion TD, which is related to the concave and convex surfaces. Therefore, slippage of the sanding belt B relative to the drive wheel 300 can be suppressed.

[0291] Furthermore, in the drive wheel 300 of the second method, if the radius b of the drive wheel flange portion... D relative to the radius a of the drive wheel contact part D proportion (b) D / a D If the value is 1.1 or higher, or 1.2 or higher, the effect of the drive wheel flange 222 in inhibiting the shedding of the sand belt B will be fully exerted.

[0292] Furthermore, in the drive wheel 300 of the second method, if (b D -a D ) / c D If the value is 0.05 or higher, it is also possible to obtain the height of the left drive wheel flange 222L corresponding to the width of the drive wheel 32, so that the drive wheel flange 222 can fully exert its effect on suppressing the shedding of the sand belt B.

[0293] Additionally, in the drive wheel 300 of the second method, if (b D -a D ) / c D If the value is 1.00 or less, the effect of the drive wheel flange 222 on suppressing the shedding of the sand belt B can be fully obtained, and the reduction in workability caused by the replacement of the sand belt B can be fully suppressed.

[0294] Furthermore, in the second type of drive wheel 300, if the height of the drive wheel flange 222 is 3mm or more, the drive wheel flange 222 can also sufficiently suppress the shedding of the sand belt B.

[0295] Furthermore, the second method appropriately has the same modifications as the first method.

[0296] Furthermore, at least one of the ribs 324 may not be in a ring shape when viewed from left to right. The ribs 324 may not be arranged along the left and right sides. The number of ribs 324 may be increased or decreased relative to the number shown in the diagram.

[0297] [Method 3]

[0298] Figure 9 This is a perspective view of the drive wheel 400 of the tubular belt sander according to the third embodiment of the present invention. Figure 10 It is a cross-sectional view of the drive wheel 400, which passes through the center in the front-rear direction and extends in the up, down, left, and right directions.

[0299] The third method is the same as the first method except for the drive wheel. For the parts of the third method that are the same as those in the first method, the same reference numerals as in the first method are appropriately used, and the explanations are omitted.

[0300] The third type of drive wheel 400 has: an outer wheel portion 402, a guide portion 404, and a plurality of (2) cover portions 406.

[0301] The outer wheel portion 402 is made of synthetic resin, more specifically, of polyamide. The outer wheel portion 402 is tubular in shape. The outer wheel portion 402 extends to the left and right.

[0302] The outer wheel portion 402 has: an outer wheel portion body 420, an outer wheel inner hole 421, a plurality of (2) drive wheel flange bases 422, and a plurality of (3) threaded holes 424.

[0303] The outer wheel body 420 is cylindrical and extends to the left and right.

[0304] The outer wheel body 420 integrally includes the inner wheel 200 of the first type.

[0305] The inner hole 421 of the outer wheel is the same as the inner hole 210 of the inner wheel in the first method.

[0306] The left drive wheel flange base 422 protrudes radially outward from the left end of the outer wheel body 420. The right drive wheel flange base 422 protrudes radially outward from the right end of the outer wheel body 420.

[0307] Each threaded hole 424 extends to the left and right and passes through the outer wheel body 420. The left and right ends of each threaded hole 424 are enlarged relative to the inner portion in the left and right direction.

[0308] The guide portion 404 and the outer wheel portion 402 are integrally formed. In addition, the outer wheel portion 402 and the guide portion 404 can be fixed to each other by means other than integral forming.

[0309] The guide portion 404 is made of rubber and is cylindrical. The guide portion 404 is an elastomer. The guide portion 404 extends laterally.

[0310] The guide portion 404 is positioned between the base portions 422 of each drive wheel flange.

[0311] The guide portion 404 has: a guide portion body 430 and a guide portion inner hole 432.

[0312] The main body 430 with the guide section is cylindrical and extends to the left and right.

[0313] The outer surface of the guide body 430 is a drive wheel belt contact portion TD that can contact the abrasive belt B. The drive wheel belt contact portion TD bulges outward in a radial direction. In the left-right direction, the drive wheel belt contact portion TD is centered at portion M ( Figure 10 It descends slowly to both sides from the apex.

[0314] The inner surface of the abrasive belt B comes into contact with the drive wheel belt contact portion TD. The belt guide body 430 conveys the abrasive belt B.

[0315] Each drive wheel flange base 422 is adjacent to the drive wheel belt contact portion TD. Each drive wheel flange base 422 is positioned on both sides of the drive wheel belt contact portion TD. Each drive wheel flange base 422 is positioned on both sides in the width direction of the drive wheel belt contact portion TD. Each drive wheel flange base 422 is positioned on both sides in the width direction of the sanding belt B.

[0316] The guide hole 432 is formed in the central part of the guide body 430 in the radial direction.

[0317] The guide portion inner hole 432 is cylindrical and extends to the left and right. The size of the guide portion inner hole 432 is the same as or approximately the same as the size of the portion of the drive wheel flange base 422 that is further inward in the left and right direction compared to the outer wheel portion 402.

[0318] The outer wheel portion 402 enters the inner hole 432 of the belt guide portion. The outer wheel portion 402 is fixed in the inner hole 432 of the belt guide portion.

[0319] Each cover 406 is made of synthetic resin. Each cover 406 is in the shape of a ring plate and extends in the front-back and up-down directions.

[0320] The covers 406 are arranged symmetrically on the left and right sides. Hereinafter, the left-side cover 406 will be described, appropriately and representatively.

[0321] The cover 406 has: a cover body 440, a central hole 442, a plurality of (3) threaded holes 444, and a peripheral portion 446.

[0322] The main body of the cover 440 is in the shape of a ring plate.

[0323] A central hole 442 is provided in the center of the cover body 440. When viewed from left to right, the outer wheel inner hole 421 enters the radially inner side of the central hole 442.

[0324] Each threaded hole 444 is opened around the central hole 442. The threaded holes 444 are arranged on an imaginary circle and are arranged circumferentially. When viewed from left to right, the threaded holes 424 of the corresponding outer ring portion 402 enter the radially inner side of the threaded holes 444. The periphery of each threaded hole 444 is formed in a shape corresponding to the enlarged portion of the threaded hole 424 and enters the enlarged portion of the threaded hole 424.

[0325] A peripheral portion 446 is disposed on the outer peripheral portion of the cover body 440. The peripheral portion 446 is annular when viewed from the left to the right. The peripheral portion 446 is curved inward in the left-right direction relative to the cover body 440. The peripheral portion 446 extends along the upper side of the drive wheel flange base 422 and the outer side in the left-right direction.

[0326] The left cover 406 is fixed to the left side of the outer wheel 402 by means of multiple (3) screws 408 entering the corresponding threaded holes 444 and 424 on the left side.

[0327] The right-side cover 406 is fixed to the right side of the outer wheel 402 by means of multiple (3) screws 408 entering the corresponding threaded holes 444 and 424 on the right side.

[0328] In the drive wheel 400, a drive wheel flange portion 448 is formed by the drive wheel flange base 422 and the peripheral portion 446. In this case, a portion of the drive wheel flange portion 448 is separate from the outer wheel portion 402.

[0329] Thus, with a portion of the drive wheel flange 448 separated from the outer wheel portion 402, the outer wheel portion 402 has a simple structure.

[0330] Furthermore, in the drive wheel 400 of the third method, if the radius b of the drive wheel flange portion... D relative to the radius a of the drive wheel contact part D proportion (b) D / a D If the value is 1.1 or 1.2 or higher, the effect of the drive wheel flange 448 in inhibiting the shedding of the sand belt B will be fully exerted.

[0331] Furthermore, in the drive wheel 400 of the third method, if (b D -a D ) / c D If the value is 0.05 or higher, it is also possible to obtain the height of the left drive wheel flange 448L corresponding to the width of the drive wheel 32, so that the drive wheel flange 448 can fully exert its effect on suppressing the shedding of the sand belt B.

[0332] Additionally, in the drive wheel 400 of the third method, if (b D -a D ) / c D If the value is below 1.00, the effect of the drive wheel flange 448 on suppressing the shedding of the sanding belt B can be fully obtained, and the reduction in workability caused by the replacement of the sanding belt B can be fully suppressed.

[0333] Furthermore, in the third type of drive wheel 400, if the height of the drive wheel flange 448 is 3mm or more, the drive wheel flange 448 can also sufficiently suppress the shedding of the sand belt B.

[0334] Furthermore, the third method appropriately has the same modifications as the first and second methods.

[0335] Alternatively, the drive wheel flange 448 can be formed solely through the peripheral portion 446 of the cover portion 406. In this case, the entire drive wheel flange 448 is separate from the outer wheel portion 402.

Claims

1. A working section structure for a belt grinder, comprising a working section in the belt grinder for performing operations on a workpiece. Its features are, The working part of the belt grinder includes: a drive wheel for mounting the sanding belt. The speed of the abrasive belt, i.e., the belt speed, is 8 m / s or less, or can be set to 8 m / s or less. The drive wheel has: a portion that contacts the sanding belt, i.e., a belt contact portion, and a flange portion adjacent to the belt contact portion.

2. The working section structure of the belt grinder according to claim 1, characterized in that, The distance between the central axis of the drive wheel and the end of the flange is also known as the flange radius b. D The distance between the central axis and the contact portion of the belt, i.e., the radius a of the contact portion of the belt. D proportion (b) D / a D The value is 1.1 or higher.

3. The working section structure of the belt grinder according to claim 1, characterized in that, The distance between the central axis of the drive wheel and the end of the flange is also known as the flange radius b. D The distance between the central axis and the contact portion of the belt, i.e., the radius a of the contact portion of the belt. D proportion (b) D / a D The value is 1.2 or higher.

4. The working section structure of the belt grinder according to any one of claims 1 to 3, characterized in that, The flange portion is located on both sides of the contact portion in the width direction. The distance between the central axis of the drive wheel and the end of either flange is also known as the flange radius b. D Subtract the distance between the central axis and the belt contact portion, i.e., the radius a of the belt contact portion. D The difference is obtained, which is then divided by the distance between the two flange portions, i.e., the flange portion spacing c. D The obtained value ((b) D -a D ) / c D The value is above 0.

05.

5. The working section structure of the belt grinder according to any one of claims 1 to 4, characterized in that, The flange portion is located on both sides of the contact portion in the width direction. The distance between the central axis of the drive wheel and the end of either flange is also known as the flange radius b. D Subtract the distance between the central axis and the belt contact portion, i.e., the radius a of the belt contact portion. D The difference is obtained, which is then divided by the distance between the two flange portions, i.e., the flange portion spacing c. D The obtained value ((b) D -a D ) / c D () is below 1.

00.

6. The working section structure of the belt grinder according to any one of claims 1 to 5, characterized in that, The height of the flange portion is 3mm or more.

7. The working section structure of the belt grinder according to any one of claims 1 to 6, characterized in that, The speed of the abrasive belt, i.e., the belt speed, can be set to below 3.4 m / s.

8. The working section structure of the belt grinder according to any one of claims 1 to 7, characterized in that, The flange is made of synthetic resin.

9. The working section structure of the belt grinder according to any one of claims 1 to 8, characterized in that, The drive wheel includes: an outer wheel portion having the flange portion, and an inner wheel portion disposed radially inward of the outer wheel portion. The outer wheel is made of synthetic resin. The inner wheel is made of metal.

10. The working section structure of the belt grinder according to claim 9, characterized in that, The outer wheel is made of polyamide.

11. The working section structure of the belt grinder according to claim 9 or 10, characterized in that, The outer wheel section also has a rubber belt guide section. The belt guide portion is disposed on the axial inner side of the flange portion and has the belt contact portion.

12. The working section structure of the belt grinder according to any one of claims 9 to 11, characterized in that, Part or all of the flange portion is integral with the outer wheel portion.

13. The working section structure of the belt grinder according to any one of claims 1 to 12, characterized in that, The contact portion includes the end faces of multiple ribs.

14. A working section structure for a belt grinder, comprising a working section in the belt grinder for performing operations on a workpiece. Its features are, The working part of the belt grinder includes: a drive wheel for mounting the sanding belt. The drive wheel has: a portion that contacts the abrasive belt, i.e., a belt contact portion, and a flange portion made of synthetic resin adjacent to the belt contact portion.

15. The working section structure of the belt grinder according to claim 14, characterized in that, The drive wheel includes: an outer wheel portion having the flange portion, and an inner wheel portion disposed radially inward of the outer wheel portion. The outer wheel is made of synthetic resin. The inner wheel is made of metal.

16. The working section structure of the belt grinder according to claim 15, characterized in that, The outer wheel is made of polyamide.

17. The working section structure of the belt grinder according to claim 15 or 16, characterized in that, The outer wheel section also has a rubber belt guide section. The belt guide portion is disposed on the axial inner side of the flange portion and has the belt contact portion.

18. The working section structure of the belt grinder according to any one of claims 15 to 17, characterized in that, Part or all of the flange portion is integral with the outer wheel portion.

19. An accessory for a belt sander, characterized in that, The accessory of the belt grinder has the working part structure of the belt grinder as described in any one of claims 1 to 18.

20. A belt polisher, characterized in that, The belt polisher has the working section structure of the belt polisher as described in any one of claims 1 to 18.

21. The belt grinder according to claim 20, characterized in that, The belt polisher includes a brushless motor that serves as the drive source for the drive wheel.

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