Power tool

Abstract

An electric tool is provided with a braking mechanism (9), a switch operating handle (41), and a sliding rod (66). Among them, the braking mechanism includes a braking component (32); the switch operating handle can move between an initial position protruding from a housing (2) and a pressed-in position where it is pressed toward the housing (2) to turn on a switch (11); the sliding rod can slide between a forward position and a backward position, and a linkage mechanism (65) is used as a link component (67), and this link component (67) is arranged between the switch operating handle and the sliding rod, and when the switch operating handle is in the pressed-in position, it moves the sliding rod to the forward position, and when the switch operating handle is in the initial position, it moves the sliding rod to the backward position. According to the present invention, with a simple structure having fewer components, the braking mechanism and the linkage mechanism linked to the operation of the switch operating handle can be maintained and have good operability and reliability.

Description

[0001] This application is a divisional application of the invention patent application with application number 201780083405.8. The application date of the original application is November 20, 2017, the priority date is January 13, 2017, and the invention name of the original application is “Power Tools”. Technical Field

[0002] The present invention relates to an electric tool such as a grinder having a brake mechanism and a linkage mechanism, wherein the brake mechanism brakes the rotation of the output shaft of a motor; and the linkage mechanism enables the brake mechanism to be linked with a switch lever to be turned on / off. Background Art

[0003] For example, Patent Document 1 discloses a grinder having a brake mechanism, wherein the brake mechanism includes a brake plate, a brake component, and a coil spring, wherein the brake plate is fixed to the output shaft of the motor; the brake component is disposed oppositely in front of the brake plate and has a brake shoe; and the coil spring pushes the brake component toward the brake plate. In addition, a linkage mechanism including a sliding component is provided in the grinder, wherein the sliding component is linked to the pressing operation (turning on operation) of the operating component (switch operating handle) for turning the switch on / off the drive motor and moves toward the brake component side, thereby causing the brake shoe to separate from the brake plate. Therefore, by pressing the switch operating handle, the switch is turned on, and the brake of the brake mechanism is released to rotate the output shaft, and when the pressing operation is released, the switch is turned off, and the brake mechanism operates to brake the output shaft.

[0004]

Prior art documents

[0005] [Patent Literature]

[0006] Patent Document 1: Japanese Patent Publication No. 5707267 Summary of the invention

[0007] [Technical problem to be solved by the invention]

[0008] In the interlocking mechanism of the above prior art, in order to move the sliding member forward and backward in a direction intersecting the pressing direction of the operating member, i.e., the switch operating lever, it is necessary to assemble the rolling elements in the sliding member or assemble the inclined guiding member for rolling the rolling elements in the switch operating lever. Therefore, the number of components of the interlocking mechanism increases, resulting in an increase in the assembly effort and cost. In addition, there is also a concern that due to the intrusion of dust and the like between the components, malfunction may occur, making the pressing operation of the switch operating lever heavier, or delaying the ON / OFF timing of the braking mechanism, thereby reducing the operability and the reliability of the interlocking.

[0009] Therefore, an object of the present invention is to provide a power tool that can maintain and have good operability and reliability for an interlocking mechanism that interlocks a braking mechanism with a switch operating lever through a simple structure with a smaller number of components.

[0010]

Technical Solution for Solving Technical Problems

[0011] To achieve the above object, the present invention provides a power tool, characterized in that

[0012] it includes a motor, a housing, a braking mechanism, a switch operating lever, a sliding member, and an interlocking mechanism, wherein

[0013] the housing houses the motor;

[0014] the braking mechanism includes a braking member that is disposed in front of the motor in the housing and can move back and forth between a rear braking position and a front braking release position, wherein the braking position is a position where the braking member brakes the output shaft of the motor, and the braking release position is a position where the braking member releases the braking of the output shaft;

[0015] the switch operating lever is disposed on the housing and can move between an initial position and a pressed position, wherein the initial position is a position where the switch operating lever protrudes from the housing, and the pressed position is a position where the switch operating lever is pressed toward the housing side to turn on (ON) a switch for driving the motor disposed in the housing;

[0016] the sliding member is disposed in the housing and can slide between a forward position and a backward position, wherein the forward position is a position where the sliding member moves the braking member toward the braking release position, and the backward position is a position where the sliding member moves the braking member toward the braking position;

[0017] the interlocking mechanism interlocks the braking mechanism with the switch operating lever,

[0018] The linkage mechanism uses a link member which is disposed between the switch operating handle and the sliding member, and when the switch operating handle is in the pressed-in position, it moves the sliding member to the forward position, and when the switch operating handle is in the initial position, it moves the sliding member to the backward position.

[0019] The so-called "disposed between the switch operating handle and the sliding member" here means the technical meaning of the link member that indirectly transmits the pushing force on the switch operating handle to the sliding member, and does not determine the configuration of the link member between the switch operating handle and the sliding member.

[0020] In addition, preferably, the link member has two arms protruding in different directions around a fulcrum and is supported in a rotatable manner. When one of the arms is pushed by the switch operating handle moved to the pressed-in position, the other arm pushes the sliding member to the forward position.

[0021] In addition, preferably, the fulcrum is supported on the housing side.

[0022] In addition, preferably, the sliding member is disposed between the switch operating handle and the link member, and the pressing portions of the one arm on the switch operating handle are provided as a left-right pair straddling the sliding member.

[0023] In addition, preferably, the lengths of the two arms of the link member are different.

[0024] In addition, preferably, the front end of the link member is rotatably connected to the sliding member, and the rear end of the link member is a linear member held by the switch operating handle.

[0025] In addition, preferably, the rear end of the link member is connected to the switch operating handle through a shaft.

[0026] To achieve the above object, the present invention provides a power tool, characterized in that

[0027] it includes a motor, a housing, a braking mechanism and a switch operating handle, wherein

[0028] the housing houses the motor;

[0029] the braking mechanism includes a braking member which is disposed in front of the motor in the housing and can move between a rear braking position and a front braking release position, wherein the braking position is the position where the braking member brakes the output shaft of the motor, and the braking release position is the position where the braking member releases the braking of the output shaft;

[0030] The switch operating handle is disposed on the housing and is movable between an initial position and a pressed position. Herein, the initial position is the position where the switch operating handle protrudes from the housing, and the pressed position is the position where the switch operating handle is pressed into the housing to turn on the switch for driving the motor disposed within the housing.

[0031] The braking member at the braking position and the switch operating handle at the initial position are integrally combined. By pressing the switch operating handle into the pressed position, the braking member moves to the braking release position.

[0032] In addition, preferably, the braking member is supported within the housing so as to be swingable back and forth about a swing fulcrum. By pressing the switch operating handle, the braking member swings forward about the swing fulcrum, thereby moving to the braking release position.

[0033] In addition, preferably, the braking member is made of metal.

[0034] In addition, preferably, the switch is disposed behind the switch operating handle, and a handle member is provided behind the switch operating handle. The handle member is linked to the operation of the switch operating handle, turns on (ON) the switch at the pressed position, and turns off (OFF) the switch at the initial position.

[0035] In addition, preferably, the handle member has a fulcrum portion, a force receiving point portion, and an acting point portion. Herein, the fulcrum portion is rotatably supported at a position behind the plunger provided on the switch; the force receiving point portion is linked to the operation of the switch operating handle; and the acting point portion presses the plunger between the fulcrum portion and the force receiving point portion.

[0036] In addition, preferably, the fulcrum portion is provided at the rearmost part of the housing.

[0037] In addition, preferably, the housing includes a motor housing that houses the motor and extends rearward, and the fulcrum portion is provided at the rear of the motor housing.

[0038]

Advantages of the Invention

[0039] According to the present invention, a linkage mechanism in which the braking mechanism is linked to the switch operating handle can be formed by a simple structure with a small number of components, thereby reducing the assembly effort and cost. In addition, since there is less concern about malfunction due to the intrusion of dust or the like, the pressing operation of the switch operating handle does not become heavy, and the linkage timing of the braking mechanism does not delay, so that good operability and reliability can be maintained.

[0040] In addition to the above effects, if the link member is a member having two arms and supported in a rotatable manner, and one arm is pushed by the switch operating handle moved to the pressed position, so that the other arm pushes the sliding member to the forward position, the pushing force of the switch operating handle can be easily converted into a force that pushes the sliding member forward. In addition, the link member can be compactly arranged to save space.

[0041] In addition to the above-mentioned effects, if the fulcrum of the link member is configured to be supported on the housing side, the link member can be easily assembled.

[0042] In addition to the above-mentioned effects, if the sliding member is arranged between the switch operating handle and the connecting rod member, and the pushing portion of one arm on the switch operating handle is arranged as a pair of left and right arms across the sliding member, the switch operating handle, the connecting rod member and the sliding member can be compactly arranged, and even if the sliding member is located between the switch operating handle and the connecting rod member, the connecting rod member can be reliably rotated by the pushing portion.

[0043] In addition to the above-mentioned effects, if the lengths of the two arms of the link member are different, and the length of the arm on the side where the switch operating handle is pushed is longer than the length of the arm on the side that pushes the sliding member, the pushing force of the switch operating handle can be increased and transmitted to the sliding member, thereby reducing the pushing force required for the switch operating handle, thereby further improving operability. On the other hand, if the length of the arm on the side that pushes the sliding member is longer than the length of the arm on the side where the switch operating handle is pushed, the rotation amount of the link member can be effectively converted into the pushing amount of the sliding member, thereby obtaining the sliding amount of the sliding member.

[0044] In addition to the above effects, if the front end of the link member is rotatably connected to the sliding member and the rear end of the link member is a linear member held by the switch operating handle, the structure of the link member is simplified and can be easily assembled to the switch operating handle.

[0045] In addition to the above-mentioned effects, if the rear end of the link member is connected to the switch operating handle via a shaft, the link member can be tilted forward as the switch operating handle is pushed in, thereby effectively pressing the switch operating handle forward.

[0046] In addition to the above-mentioned effects, if the brake component is supported in the shell so as to be able to swing forward and backward with a swing fulcrum as the center, and the brake component is moved toward the brake release position by swinging forward with the swing fulcrum as the center by pressing the switch operating handle, the brake component can be linked with the operation of the switch operating handle and reliably moved to the brake release position.

[0047] In addition, besides the above effects, if the braking component is made of metal, the rigidity of the braking component can be improved, thereby enhancing the durability and reliability of the braking mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Central longitudinal sectional view of the grinder of Mode 1 (switch in off state).

[0049] Figure 2 In (A) represents Figure 1 the cross-section of A-A of Figure 2 In (B) represents the cross-section of A'-A'.

[0050] Figure 3 Stereo exploded view when observing the motor housing and the switch operating handle from the rear side.

[0051] Figure 4 Stereo exploded view when observing the motor housing and the switch operating handle from the front side.

[0052] Figure 5 Central longitudinal sectional view of the grinder of Mode 1 (switch in on state).

[0053] Figure 6 In (A) represents the cross-section of B-B, Figure 6 In (B) represents the cross-section of B'-B'.

[0054] Figure 7 Central longitudinal sectional view of the grinder of Mode 2 (switch in off state).

[0055] Figure 8 Central longitudinal sectional view of the grinder of Mode 2 (switch in on state).

[0056] Figure 9 Central longitudinal sectional view of the grinder of Mode 3 (switch in off state).

[0057] Figure 10 Central longitudinal sectional view of the grinder of Mode 3 (switch in on state).

[0058] Figure 11 Explanation diagram showing a modified example of the support structure of the handle component, Figure 11 In (A) represents the switch off state, Figure 11 In (B) represents the switch on state. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0060] (Mode 1)

[0061] Figure 1 A central longitudinal sectional view of a grinder, which is an example of a power tool. In this grinder 1, a housing 2 includes a motor housing 3, a brake holder 4, a gear housing 5, and a rear cover 6. Among them, the motor housing 3 houses a motor 7 and extends in the front-rear direction; the brake holder 4 is assembled in front of the motor housing 3 and houses a braking mechanism 9; the gear housing 5 is assembled in front of the brake holder 4 and allows a main shaft 10 to protrude downward; the rear cover 6 is assembled to the rear of the motor housing 3 and houses a switch 11 having a plunger 12.

[0062] The motor housing 3 is cylindrical for holding the motor 7 in a forward-facing posture. The output shaft 8 of the motor 7 passes through the cylindrical brake holder 4 and a bearing plate 13 that holds a bearing 14 in front of it and protrudes into the gear housing 5. A first bevel gear 15 is tightly attached to the tip of the output shaft 8.

[0063] The motor 7 is a commutator motor having a stator 16 and a rotor 17. Among them, the stator 16 is held in the motor housing 3; the rotor 17 passes through the stator 16 and has an output shaft 8 at its axis. A fan 18 for motor cooling is provided on the output shaft 8 in front of the stator 16, and a commutator 19 is provided at the rear of the rotor 17. The rear end of the output shaft 8 is supported by a bearing 21, and the bearing 21 is held by a holder portion 20 provided at the rear of the motor housing 3. A baffle plate 22 is provided at the front end opening of the motor housing 3. The baffle plate 22 is provided outside the fan 18 and conveys the wind of the fan 18 forward.

[0064] Inside the gear housing 5, the main shaft 10 is supported orthogonally to the output shaft 8 by upper and lower bearings 23, 24. A second bevel gear 25 provided on the upper side of the main shaft 10 meshes with the first bevel gear 15. At the lower end of the main shaft 10 protruding from the gear housing 5, a tip tool (here a disc-shaped grinding wheel) 26 is detachably mounted by an inner flange 27 and an outer flange 28. A tool cover 29 that covers the rear half of the tip tool 26 from above is mounted at the lower part of the gear housing 5, and a plurality of exhaust ports 30 are formed on the upper front surface of the gear housing 5.

[0065] The braking mechanism 9 includes a brake plate 31, a braking member 32, and a helical spring 33. Among them, the brake plate 31 is integrally fixed to the output shaft 8; the braking member 32 is penetrated by the output shaft 8 in front of the brake plate 31 and can move back and forth; the helical spring 33 is penetrated by the output shaft 8 between the braking member 32 and the bearing plate 13 in front of the braking member 32 and applies a force to the braking member 32 in the rearward direction. The braking member 32 is made of metal, and a brake shoe 34 is closely attached to its rear surface. Therefore, in the normal state, the braking member 32 is pushed by the helical spring 33 to the braking position (the on position of the braking mechanism 9) where the brake shoe 34 is pressed against the brake plate 31.

[0066] As Figure 2 shown, the rear cover 6 is formed by assembling left and right split shells 6a and 6b, and is in the shape of a cup with an open front, and is assembled to the rear part of the motor housing 3 in a posture of accommodating the bracket portion 20 and the switch receiving portion 35 integrally formed at its rear part. The switch receiving portion 35 is in the shape of a square box extending rearward in the rear cover 6 with an open lower surface. The switch 11 is held in a posture of applying a downward protruding force to the plunger 12, and is turned on (ON) by pressing the plunger 12. A power cord 36 that penetrates the rear surface of the rear cover 6 and is pulled out rearward is connected to the rear end of the switch receiving portion 35. On the upper side of the power cord 36, a plurality of air inlets 37 are formed on the rear surface of the rear cover 6.

[0067] In addition, as Figures 2 to 4 shown, a bottom plate portion 38 is respectively formed on the lower surfaces of the motor housing 3 and the rear cover 6, and a pair of descending portions 39 that protrude downward and toward each other from the left and right of the bottom plate portion 38 are formed. A concave handle holding portion 40 that opens downward is formed in the front-rear direction across the lower surfaces of the motor housing 3 and the rear cover 6.

[0068] A switch operating handle 41 for turning the switch 11 on (ON) / off (OFF) is provided on the handle holding portion 40. The switch operating handle 41 is in the shape of a strip plate extending in the front-rear direction along the opening of the handle holding portion 40 when viewed from above, and a pair of side plates 42 and a rear plate 43 that stand up upward are respectively formed on its left and right and rear ends. A pair of shaft portions 44 in the left-right direction are formed at its front end. The pair of shaft portions 44 are held above a baffle plate 45, and the baffle plate 45 makes the pair of shaft portions 44 protrude rearward from the lower surface of the front end of the motor housing 3. A locking piece 46 protrudes rearward at the upper end of the rear plate 43.

[0069] Furthermore, a bulging portion 47 is formed on the lower surface side of the rear cover 6. The bulging portion 47 protrudes downward with approximately the same left-right width as the switch operating handle 41, and bulges downward until the rear plate 43 of the switch operating handle 41 as it faces forward. An abutting portion 48 that bends upward at the front end of the bulging portion 47 and abuts against the locking piece 46 of the switch operating handle 41 is formed.

[0070] Therefore, the switch operating handle 41 is supported so as to be able to swing in the vertical direction around the shaft portion 44, and is restricted from swinging downward at a position where the locking piece 46 of the rear plate 43 abuts against the abutment portion 48 of the rear cover 6. This position becomes an initial position protruding downward from the opening of the handle holding portion 40, and the push-in operation into the handle holding portion 40 can be performed from this position to the push-in position described later.

[0071] On the other hand, a pair of left and right push pieces 49 for pushing the link member 67 described later are provided on the upper surface of the switch operating handle 41 at a position forward of the rear plate 43 and sandwiched by the pair of side plates 42, and an opening 50 is formed in front of the pair of left and right push pieces 49, and a lock button (lock off button) 51 is held in the opening 50. The lock button 51 is supported in the middle portion by a pin 52 in the left and right directions in the opening 50, and can rotate to an upright posture and a fallen posture, wherein the upright posture is a posture in which the lock button 51 abuts against a stopper 53 that stands obliquely forward from the rear edge of the opening 50 and protrudes downward from the opening 50; and the fallen posture is a posture in which the lock button 51 falls forward in the opening 50 and is stored in the switch operating handle 41. The locking button 51 is normally biased to rotate toward the upright position by a torsion spring 54 disposed outside the pin 52 and having its two ends locked between the locking button 51 and the opening 50. A pair of triangular protrusions 55 are formed on the upper ends of the locking button 51 in the upright position, which protrude backward and abut against the stopper 53.

[0072] A pair of left and right guide walls 56 are provided in the front-to-back direction inside the handle retaining portion 40 on the side of the motor housing 3 and on the inner side of a pair of left and right descending portions 39, and a pair of triangular notches 57 are formed on the rear lower surface of the pair of guide walls 56. A pair of protrusions 55 of the locking button 51 in the inverted position can be fitted into the pair of notches 57.

[0073] Therefore, the switch operating lever 41 can be pushed in from the initial position to the pushed-in position where the pair of protrusions 55 of the lock button 51 in the lying position fit into the pair of notches 57 of the pair of guide walls 56 .

[0074] (Description of handle parts)

[0075] like Figure 1As shown, the rear end of the switch operating handle 41 here does not reach the plunger 12 of the switch 11, and a handle member 60 is provided behind the switch operating handle 41. At the rearmost part in the bulging part 47 of the rear cover 6 located below the plunger 12, the fulcrum part 61 of the handle member 60, which is provided at the rear end and is axial in the left-right direction, is held in a rotatable manner, and the force point part 62 at the front end of the handle member 60 is a strip-shaped plate body extending to the upper side of the rear plate 43 of the switch operating handle 41, and the action point part 63 of the handle member 60 located between the fulcrum part 61 and the force point part 62 abuts against the plunger 12 in the protruding position. In this state, the handle member 60 causes the locking piece 46 of the switch operating handle 41 to be locked to the abutment part 48 through the plunger 12, and applies force to the switch operating handle 41 toward the lower side position as the initial position.

[0076] Therefore, when the switch operating handle 41 in the initial position is pressed into the pressed position, Figure 5 As shown, the rear plate 43 and the locking piece 46 can press the force point portion 62 of the handle member 60 upward, so that the handle member 60 presses the plunger 12 toward the action point portion 63 with the fulcrum portion 61 as the center, so that the switch 11 swings to the upper position of the ON action. At this time, since the action point portion 63 is located between the fulcrum portion 61 and the force point portion 62 of the handle member 60, even if the switch operating handle 41 is pressed with a force of approximately half the action load of the plunger 12, the plunger 12 can be pressed in by the handle member 60.

[0077] (Explanation of linkage mechanism)

[0078] Furthermore, a linkage mechanism 65 is provided on the upper side of the switch operating handle 41, and the linkage mechanism 65 slides in conjunction with the pressing operation of the operating rod 41 to turn on / off the brake mechanism 9. The linkage mechanism 65 includes a slide bar 66 provided in the handle holding portion 40 and a link member 67 provided behind the slide bar 66.

[0079] First, if Figure 3 , Figure 4 As shown, the slide rod 66 is provided between the pair of guide walls 56 so as to be movable forward and backward along the lower surface of the bottom plate portion 38. The slide rod 66 is a plate-like body having a width smaller than the interval between the pair of push pieces 49 of the switch operating handle 41, and the front end thereof protrudes forward of the motor housing 3 and approaches the rear surface of the brake member 32 in the brake position. A thick wall portion 68 is formed on the lower side at the rear end of the slide rod 66, and the rear surface of the thick wall portion 68 is an inclined surface 69 inclined rearward and downward.

[0080] The link member 67 is a plate-like body having a front arm 70 and a rear arm 71 that protrude at a predetermined angle at both front and rear ends and are L-shaped when viewed from the side. Between a pair of receiving protrusions 72 erected in the left-right direction on the lower surface of the bracket portion 20, the front and rear arms 70, 71 are pivotally fixed by a pin 73 so as to be rotatable. In this state, the front arm 70 extends forward above the sliding rod 66, and a widened portion 74 having a larger left-right width than the left-right width of the sliding rod 66 provided at the top is located above the pair of pressing pieces 49. The rear arm 71 extends rearward behind the thick-walled portion 68 of the sliding rod 66, and at its tip, a bent piece 75 that bends forward and wraps around the lower side of the inclined surface 69 of the thick-walled portion 68 is formed.

[0081] Therefore, in this linkage mechanism 65, when the switch operating handle 41 is in the initial position, the pair of left and right pressing pieces 49 protrude slightly upward at the top in a posture straddling the sliding rod 66 from left and right. At this time, the sliding rod 66 is in the retracted position where its front end is close to the braking member 32 at the braking position, and the lower edge of the inclined surface 69 of the thick-walled portion 68 at the rear end abuts against the rear arm 71 of the link member 67 above the bent piece 75. Therefore, as Figure 1 、 Figure 2 shown, the link member 67 is biased to the first rotation position where the widened portion 74 of the front arm 70 abuts against the top ends of the pair of pressing pieces 49.

[0082] When the switch operating handle 41 is pressed from here to the pressed position, since the pair of left and right pressing pieces 49 rise and push the front arm 70 of the link member 67 upward, the link member 67 rotates to the right in Figure 1 and, as Figure 5 、 Figure 6 shown, becomes the second rotation position where the rear arm 71 moves forward. In this second rotation position, the rear arm 71 slides the sliding rod 66 forward, and the lower end of the braking member 32 is pushed forward and upward against the biasing force of the coil spring 33. In this advanced position, the braking member 32 is moved to the braking release position where the brake shoe 34 separates from the brake plate 31.

[0083] Here, the rear end of the thick-walled portion 68 is made into the inclined surface 69, and the distance between the position where its lower edge abuts against the rear arm 71 and the center of the pin 73 is ensured to be long, so that the distance R2 from the center of the pin 73 to the abutting position of the lower edge of the rear arm 71 and the inclined surface 69 is set to be slightly longer than the distance R1 from the center of the pin 73 to the abutting position of the widened portion 74 of the front arm 70 and the pair of pressing pieces 49. Therefore, the rotation amount of the front arm 70 that rotates the link member 67 can be effectively converted into the pushing amount of the rear arm 71 that pushes the sliding rod 66, and thus the sliding amount of the sliding rod 66 can be obtained.

[0084] In addition, when the rear arm 71 presses the sliding rod 66, since the bent piece 75 at the top winds around to the lower side of the lower edge of the inclined surface 69, the bent piece 75 at the top can reliably engage with the inclined surface 69 to press the thick wall portion 68.

[0085] (Explanation of the operation of the grinding machine)

[0086] In the grinding machine 1 configured as described above, when the Figure 1 、 Figure 2 switch 11 is in the OFF state, as described above, the handle member 60 is located at the lower position where it does not press the plunger 12, and the switch operating handle 14 is also at the initial position. Therefore, since the link member 67 is also at the first rotation position and the sliding rod 66 is at the retracted position, the braking member 32 is held at the braking position where the brake shoe 34 is pressed against the brake plate 31. In addition, since the locking button 51 is in the upright posture abutting against the stopper portion 53 and abuts against the lower surfaces of the pair of guide walls 56, the state where the pressing-in of the switch operating handle 41 is restricted by the locking button 51 is achieved.

[0087] When the lower end of the locking button 51 is rotated backward from here with the finger holding the motor housing 3 that forms a grip, and the locking button 51 is in the lying posture, the restriction on the pressing-in of the switch operating handle 41 is released, so that the switch operating handle 41 can be directly pressed into the pressing-in position where the pair of protrusions 55 are fitted into the pair of notches 57 of the pair of guide walls 56. Then, as Figure 5 、 Figure 6 shown, the pair of pressing pieces 49 push up the front arm 70 of the link member 67 to rotate the link member 67 to the second rotation position, and the sliding rod 66 is slid to the forward position by the rear arm 71, so that the brake shoe 34 of the braking member 32 is separated from the brake plate 34 to release the braking. At the same time, the handle member 60 swings upward to press the plunger 12, thereby turning on (ON) the switch 11. As a result, power is supplied to the motor 7, the output shaft 8 whose braking is released rotates, and the main shaft 10 rotates through the first bevel gear 15 and the second bevel gear 25. Therefore, grinding operations and the like can be performed by the tip tool 26 that rotates together with the main shaft 10.

[0088] In addition, when the fan 18 rotates along with the rotation of the output shaft 8, external air is sucked in from the air inlet at the rear end of the rear cover 6, directly cools the motor 7 inside the motor housing 3, and then is discharged from the exhaust port 30 of the gear housing 5 through the brake bracket 4.

[0089] On the other hand, when the pressing of the switch operating handle 41 is released, the handle member 60 returns to the lower position, releasing the pressing on the plunger 12, turning off the switch 11 (OFF), thereby stopping the power supply to the motor 7, and returning the switch operating handle 41 to the initial position. At the same time, the braking member 32 returns to the braking position by the biasing force of the spiral spring 33, presses the brake shoe 34 against the brake plate 31 to brake the rotation of the output shaft 8, and slides the sliding rod 66 backward to press the rear arm 71 backward, thereby returning the link member 67 to the first rotational position.

[0090] (Invention effects related to the linkage mechanism)

[0091] Thus, according to the grinder 1 of the above-described method 1, the linkage mechanism 65 that links the braking mechanism 9 and the switch operating handle 41 is the link member 67, which is provided between the switch operating handle 41 and the sliding rod 66, and when the switch operating handle 41 is in the pressed position, the sliding rod 66 is moved to the forward position, and when the switch operating handle 41 is in the initial position, the sliding rod 66 is moved to the backward position. Thus, the sliding rod 66 can be linked with the operation of the switch operating handle 41 only through the link member 67. Therefore, the linkage mechanism 65 can be formed by a simple structure with a small number of components, reducing the assembly effort and cost. In addition, since there is less concern about malfunction due to the intrusion of dust, etc., the pressing operation of the switch operating handle 41 does not become heavy or the linkage timing of the braking mechanism 9 does not delay, so that good operability and reliability can be maintained.

[0092] In particular, the structure here is such that the link member 67 is a rotating member that has two front and rear arms 70, 71 that protrude in different directions around the pin 73 and is supported rotatably. The front arm 70 is pressed by the switch operating handle 41 that is moved to the pressed position, and thereby the rear arm 71 presses the sliding rod 66 to the forward position. Therefore, the pushing force from below the switch operating handle 41 can be easily converted into the forward pushing force on the sliding rod 66. In addition, the link member 67 can be arranged in a space-saving and compact manner.

[0093] In addition, since the pin 73 is supported on the housing 2 side, the assembly of the link member 67 can also be easily performed.

[0094] And, since the sliding rod 66 is arranged between the switch operating handle 41 and the link member 67, and a pair of pressing pieces 49 of the switch operating handle 41 are arranged as a left and right pair across the sliding rod 66, the switch operating handle 41, the link member 67, and the sliding rod 66 can be arranged compactly, and even when the sliding rod 66 is located between the switch operating handle 41 and the link member 67, the link member 67 can be reliably rotated by the pair of pressing pieces 49.

[0095] In addition, in the link member 67, since the rear arm 71 is made longer than the front arm 70, the rotation amount of the front arm 70 rotating the link member 67 can be effectively converted into the pressing amount of the rear arm 71 pressing the slide rod 66, thereby obtaining the sliding amount of the slide rod 66.

[0096] Since the pressing force of the switch operation handle 41 can be increased to be transmitted to the slide rod 66, the pressing force required for the switch operation handle 41 can be reduced, thereby further improving the operability.

[0097] Moreover, since the brake member 32 is made of metal, the rigidity of the brake member 32 can be improved, thereby enhancing the durability and reliability of the braking mechanism 9.

[0098] (Invention effects related to the handle member)

[0099] Furthermore, in the grinder 1 according to the above-described mode 1, the switch 11 is disposed behind the switch operation handle 41, and a handle member 60 is provided behind the switch operation handle 41. The handle member 60 is linked to the operation of the operation rod 41, turns on (ON) the switch 11 at the pressing position, and turns off (OFF) the switch 11 at the initial position. Thus, the pressing operation of the switch operation handle 41 can be performed with a load smaller than the operating load of the switch 11. In addition, even if the switch 11 is disposed at the rear, since it is not necessary to dispose the switch operation handle 41 below the switch 11, the holding position of the housing 2 for operating the switch operation handle 41 can be maintained at the front side, improving the operability and also enhancing the design freedom. Also, since the hand holding the housing 2 does not block the air inlet 37 for motor cooling, there is no concern about reducing the cooling function.

[0100] In particular, here the handle member 60 is a member having a fulcrum portion 61, a force receiving point portion 62, and an action point portion 63. Thus, even if the switch operation handle 41 is pressed with a force approximately half of the operating load of the plunger 12, the plunger 12 can be pressed by the handle member 60, where the fulcrum portion 61 is rotatably supported at a position behind the plunger 12 provided on the switch 11; the force receiving point portion 62 is linked to the operation of the switch operation handle 41; and the action point portion 63 presses the plunger 12 between the fulcrum portion 61 and the force receiving point portion 62.

[0101] In addition, since the fulcrum portion 61 is provided at the rearmost part of the housing 2, the downward inclination angle of the handle member 60 at the initial position becomes smaller, and even if the handle member 60 is provided, the downward protrusion amount of the housing 2 can be suppressed.

[0102] Also, since a braking member 32 is provided inside the housing 2, the braking member 32 can move between a braking position and a braking release position. Herein, the braking position is the position where the braking member 32 brakes the output shaft 8 of the motor 7 when the switch operating lever 41 is in the initial position; the braking release position is the position where the braking member 32 releases the braking of the output shaft 8 when the switch operating lever 41 is in the pressed position. Thus, the operating load on the switch operating lever 41 that links the braking member 32 can be effectively reduced.

[0103] In addition, in the above-described Mode 1, the link member is provided on the motor housing side and the pressing piece is provided on the switch operating lever. On the contrary, the link member can be axially fixed inside the switch operating lever with the front and rear arms open toward the motor housing side. On the other hand, the pressing piece can be erected on the motor housing side. In this case, by pressing the switch operating lever, the pressing piece can also push the front arm of the link member over the sliding rod to rotate the link member, and the sliding rod can be pushed forward by the rear arm.

[0104] In addition, in the above-described Mode 1, the front and rear arms of the link member are configured to abut against the pressing piece and the sliding rod respectively. However, the pressing piece and the front arm can also be rotatably connected by a pin or the like, or the rear end of the sliding rod and the rear arm can be rotatably connected by a pin or the like.

[0105] Moreover, in the link member, contrary to the above-described Mode 1, the front arm pushed by the switch operating lever can be made longer than the rear arm that pushes the sliding rod. If the lengths of the arms are made different in this way, the pressing force of the switch operating lever can be increased to be transmitted to the sliding rod, so that the pressing force required for the switch operating lever can be reduced, further improving the operability. Of course, the lengths of the two arms can also be the same without making them different.

[0106] Next, other modes of the present invention will be described. However, the same reference numerals are given to the structural parts that are the same as those in Mode 1, and repeated descriptions are omitted.

[0107] (Mode 2)

[0108] In Figure 7In the grinding machine 1A shown, in the linkage mechanism 65A, the link member 67A is disposed inside the rear end of the switch operating lever 41. The link member 67A is not L-shaped but a straight flat plate, and its rear end is pivotally fixed in a rotatable manner by a rear side pin 80 in the left-right direction at the lower front side of the rear plate 43 of the switch operating lever 41. On the other hand, its front end is pivotally fixed in a rotatable manner by a front side pin 81 to the thick wall portion 68 of the slide rod 66. The front end of the link member 67A is formed in a fork shape, and a roller 82 having a middle diameter larger than the thickness of the thick wall portion 68 in the vertical direction is pivotally fixed by the front side pin 81. In addition, no pressing piece is provided on the motor housing 3.

[0109] In this linkage mechanism 65A, as Figure 7 shown, when the switch operating lever 41 is in the initial position, with respect to the slide rod 66 in the retracted position, the link member 67A is in an inclined posture standing obliquely forward from the lower front side of the rear plate 43 of the switch operating lever 41, and the roller 82 abuts against the bottom plate portion 38.

[0110] When the switch operating lever 41 is pressed from here to the pressed position, as Figure 8 shown, the link member 67A lies forward in the switch operating lever 41 while rolling the roller 82 forward, causing the slide rod 66 to be straight. Therefore, since the slide rod 66 is pushed by the link member 67A and slides to the forward position, the braking member 32 can be pressed in to release the braking. If the pressing of the switch operating lever 41 is released, the slide rod 66 slides back to the retracted position by the braking member 32 restored to the braking position by the biasing force of the coil spring 33, and the link member 67A returns to Figure 7 the inclined posture. The operation of the handle member 60 is the same as in Mode 1.

[0111] Thus, in the grinding machine 1A of the above-described Mode 2, the linkage mechanism 65A that links the braking mechanism 9 with the switch operating lever 41 is the link member 67A. This link member 67A is disposed between the switch operating lever 41 and the slide rod 66, and moves the slide rod 66 to the forward position when the switch operating lever 41 is in the pressed position and moves the switch operating lever 66 to the retracted position when the switch operating lever 41 is in the initial position. Thereby, the slide rod 66 can be linked with the operation of the switch operating lever 44 only by the link member 67A. Therefore, the linkage mechanism 65A can be formed by a simple structure with a small number of components, reducing the assembly effort and cost. In addition, since there is less concern about malfunction due to the intrusion of dust, etc., the situation where the pressing operation of the switch operating lever 41 becomes heavy or the linkage timing of the braking mechanism 9 is delayed does not occur, and thus good operability and reliability can be maintained.

[0112] In particular, here, since the link member 67A is connected to the slide rod 66 in a rotatable manner with its front end and its rear end is held by the switch operating lever 41, the structure of the link member 67A can be simplified and the assembly of the switch operating lever 41 can be easily performed.

[0113] In addition, since the rear end of the link member 67A is connected to the switch operating lever 41 by the rear side pin 80, the link member 67A can be tilted forward as the switch operating lever 41 is pressed in, thereby effectively pushing the switch operating lever 41 forward.

[0114] Furthermore, in the above-described Mode 2, a roller is provided at the connection portion between the slide rod and the link member, but the roller can also be omitted. In addition, the rear end of the link member is connected by the rear side pin, but instead of this shaft fixing method, the rear end of the link member can be fitted into a recess provided on the inner surface of the switch operating lever for holding.

[0115] (Mode 3)

[0116] In Figure 9 the grinder 1B shown, a link member and a slide rod are not provided in the linkage mechanism 65B, and a connection plate 85 extending rearward at a right angle is integrally formed at the lower end of the brake member 32. The left-right direction fulcrum pin 86 fixed to the upper side of the front portion of the connection plate 85 is rotatably supported by the brake bracket 4. At the rear side of the fulcrum pin 86, the front end of the switch operating lever 41A without a shaft portion and a locking knob is fixed to the lower side of the connection plate 85. At the front side of the fulcrum pin 86, a rib 87 for maintaining the angle between the brake member 32 and the connection plate 85 is provided between the brake member 32 and the connection plate 85.

[0117] In this linkage mechanism 65B, as Figure 9 shown, similar to Mode 1 and Mode 2, the switch operating lever 41A is biased to the initial position by the lever member 60 biased downward by the plunger 12. However, here, the connection plate 85 extending rearward from the brake member 32 biased to the braking position by the coil spring 33 also helps to keep the switch operating lever 41A in the initial position.

[0118] As Figure 10 shown, when the switch operating lever 41A is pressed from here to the pressed-in position, as the front end portion of the switch operating lever 41A swings upward, the connection plate 85 and the brake member 32 rotate counterclockwise about the fulcrum pin 86. Therefore, the brake member 32 can be moved to the brake release position where the brake shoe 34 separates from the brake plate 31. If the pressing of the switch operating lever 41A is released, the brake member 32 returns to the braking position due to the biasing force of the coil spring 33, and the switch operating lever 41A integrated with the brake member 32 returns to the initial position. The operation of the lever member 60 is the same as in Mode 1.

[0119] Thus, in the grinder 1B of the above-described Mode 3, the brake member 32 in the braking position and the switch operating lever 41A in the initial position are integrally coupled. By pressing the switch operating lever 41A into the pressing position, the brake member 32 moves to the brake release position. Thereby, the brake member 32 can be directly linked to the operation of the switch operating lever 41A. Therefore, a linkage mechanism 65B can be formed with a simple structure having a smaller number of components, and the assembly effort and cost are also reduced. In addition, since there is less concern about malfunction due to intrusion of dust or the like, good operability and reliability can be maintained.

[0120] In particular, here the brake member 32 is configured to be supported in the housing 2 so as to be able to swing back and forth about the fulcrum pin 86. By pressing the switch operating lever 41A, the brake member 32 swings forward about the fulcrum pin 86 and moves to the brake release position. Therefore, the brake member 32 can be linked to the operation of the switch operating lever 41A and reliably move to the brake release position.

[0121] In addition, in the above-described Mode 3, a connecting plate is formed on the brake member to be coupled to the switch operating lever. However, it is also possible to form an upward-facing connecting plate at the front end of the switch operating lever and fix it to the front surface of the brake member, or to provide an L-shaped member straddling the two members to couple the brake member and the switch operating lever.

[0122] Further, in the above-described Mode 3, the brake member is supported so as to be able to swing back and forth about the fulcrum pin. However, it is also possible not to provide such a swing fulcrum, and even if the brake member is in a free state, the brake member can be linked to the pressing operation of the switch operating lever and move to the brake release position.

[0123] Moreover, in each mode, the mode of the handle member can be appropriately changed. Needless to say, the shape, and the positional relationship of the fulcrum portion, the force receiving point portion, and the acting point portion are not limited to the above-described mode.

[0124] In addition, the fulcrum portion is not limited to the structure held by the rear cover. As Figure 11 shown, it is also possible to project a downward-facing support rib 90 from the switch receiving portion 35 of the motor housing 3 and axially fix the fulcrum portion 61 of the handle member 60 to the support rib 90. Figure 11 Mode 1 is exemplified, but it can also be adopted in Modes 2 and 3.

[0125] Thus, if the fulcrum portion 61 is provided at the rear of the motor housing 3, the handle member 60 and the switch 11 can be pre-assembled to the motor housing 3 together, thereby facilitating the assembly of the rear cover 6.

[0126] In addition, in the grinder, the switch operating handle is not limited to being provided on the lower surface side of the housing, and it can also be provided on the upper surface side or the side surface side, or the motor can be a brushless motor, or a battery pack as a power source can be installed at the rear end of the housing. Of course, the technical solutions related to the linkage mechanism and the handle member of the braking mechanism can be applied singly or together to power tools other than the grinder.

[0127]

Explanation of Reference Numerals

[0128] 1, 1A, 1B: Grinder; 2: Housing; 3: Motor housing; 4: Braking bracket; 5: Gear housing; 6: Rear cover; 7: Motor; 8: Output shaft; 9: Braking mechanism; 10: Spindle; 11: Switch; 12: Plunger; 20: Bracket portion; 26: Tip tool; 31: Braking plate; 32: Braking member; 33: Helical spring; 34: Braking shoe; 35: Switch receiving portion; 40: Handle holding portion; 41, 41A: Switch operating handle; 42: Side plate; 43: Rear plate; 44: Shaft portion; 45: Baffle; 46: Locking piece; 47: Bulging portion; 48: Contact portion; 49: Pushing piece (pushing portion); 50: Opening; 51: Locking button; 53: Stopper; 56: Guide wall; 60: Handle member; 61: Fulcrum portion; 62: Force receiving point portion; 63: Acting point portion; 65, 65A, 65B: Linkage mechanism; 66: Sliding rod (sliding member); 67, 67A: Link member; 68: Thick wall portion; 69: Inclined surface; 70: Forearm (one arm); 71: Rear arm (the other arm); 72: Receiving protrusion; 73: Pin (fulcrum); 74: Widening portion; 75: Bent piece; 80: Rear side pin (shaft); 81: Front side pin; 82: Roller; 85: Connecting plate; 86: Fulcrum pin (swinging fulcrum).

Claims

1. An electric tool, characterized in that, a motor and a switch for driving the motor are housed in a housing. On the other hand, a switch operating handle is provided in the housing, and the switch operating handle can move between an initial position and a pressed position. Here, the initial position is the position where the switch operating handle protrudes from the housing, and the pressed position is the position where the switch operating handle is pressed toward the housing side to turn on the switch. The switch is arranged behind the switch operating handle, and a handle member separated from the switch operating handle is provided behind the switch operating handle. The handle member is linked to the operation of the switch operating handle, turns on the switch at the pressed position, and turns off the switch at the initial position. The handle member has a fulcrum portion, a force-receiving point portion, and an action point portion. Among them, the fulcrum portion is rotatably supported at a position behind the plunger provided on the switch; the force-receiving point portion is linked to the operation of the switch operating handle by being pressed by the switch operating handle; the action point portion presses the plunger between the fulcrum portion and the force-receiving point portion.

2. The electric tool according to claim 1, characterized in that, The fulcrum portion is provided at the rearmost part of the housing.

3. The electric tool according to claim 1 or 2, characterized in that, The housing includes a motor housing that houses the motor and extends rearward, and the fulcrum portion is provided at the rear of the motor housing.

4. The electric tool according to claim 3, characterized in that, A switch receiving portion for holding the switch is integrally formed at the rear of the motor housing, and the fulcrum portion is provided on the switch receiving portion.

5. The electric tool according to claim 1, characterized in that, The switch operating handle is in the shape of a strip plate extending in the front-rear direction, and the front end is rotatably supported by the housing, and the rear end can swing between the initial position and the pressed position.

6. The electric tool according to claim 5, characterized in that, The handle member is a strip-shaped plate body extending in the front-rear direction behind the switch operating handle, the rear end thereof is the fulcrum portion and the front end thereof is the force-receiving point portion, and the action point portion between the fulcrum portion and the force-receiving point portion abuts against the plunger at the protruding position.

7. The electric tool according to claim 6, characterized in that, The handle member positions the force-receiving point portion at a position inside the rear end of the switch operating handle, and applies a force to the switch operating handle through the plunger to the rotation position as the initial position.

8. The electric tool according to claim 7, characterized in that, The switch operating handle and the handle member are provided on the lower surface of the housing, and the switch operating handle protrudes downward from the housing at the initial position.

9. The electric tool according to claim 1, characterized in that, A braking mechanism including a braking component is provided inside the housing. The braking component is capable of moving between a braking position and a braking release position. Among them, the braking position is the position where the output shaft of the motor is braked at the initial position of the switch operating handle; the braking release position is the position where the braking of the output shaft is released at the pressed-in position of the switch operating handle.

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