CN107081473B

CN107081473B - Power tool

Info

Publication number: CN107081473B
Application number: CN201610087265.9A
Authority: CN
Inventors: 陈国军; 吉绍山; 夏连明
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2016-02-16
Filing date: 2016-02-16
Publication date: 2021-03-16
Anticipated expiration: 2036-02-16
Also published as: CN107081473A

Abstract

The invention discloses a power tool, which comprises a machine body, a cutting assembly and a connecting assembly, wherein the machine body is provided with a cutting assembly and a connecting assembly; the cutting assembly is used for supporting the bottom plate on the surface of the workpiece when the cutting assembly comprises a saw blade and a workpiece, the motor is arranged in the machine body and used for driving the saw blade to rotate, and the machine body is connected to the bottom plate in a linearly movable mode through the connecting assembly. Above-mentioned power tool, when needing to use this power tool to cut, the relative fuselage rectilinear movement of bottom plate, because the moving direction of bottom plate is the rectilinear motion of perpendicular to bottom plate, consequently the handheld power tool of operator only needs push down power tool, can realize the saw bit and down cut by the cutting piece, operate comfortablely.

Description

Power tool

Technical Field

The present invention relates to the field of power tools.

Background

The existing power tool is generally an electric circular saw, and cutting is performed by the electric circular saw. The slide rail part of the existing electric saw blade realizes the action of downward cutting of the saw blade through the movement of a bearing in an arc groove. Because the motion trail in the saw blade cutting process is circular arc, the linear motion can not be realized, and when the saw blade cuts downwards, the operator is required to convert the direction of the electric circular saw, so that the electric circular saw is poor in comfort during operation.

The power tool generally comprises a saw blade for processing a workpiece, a machine body for accommodating the saw blade, a bottom plate for abutting against the workpiece, and a through hole for the saw blade to pass through to cut the workpiece, wherein the machine body and the bottom plate are generally rotatably connected. In addition, when a user needs to use a tool to perform a slotting operation in the middle of a workpiece, the circular arc-shaped track of the saw blade makes it difficult for the user to predict the final cutting position of the saw blade, and the position of the tool needs to be adjusted back and forth during slotting cutting, thereby increasing the difficulty of operation and the requirement on experience and skill of the operator.

Therefore, it is necessary to provide a new power tool to solve the above problems.

Disclosure of Invention

In view of the above, it is desirable to provide a power tool that is comfortable to operate and can cut at a constant holding angle, in order to solve the problem of poor cutting operation comfort.

A power tool comprising a body, a cutting assembly and a connecting assembly; the cutting assembly is used for supporting the bottom plate on the surface of the workpiece when the cutting assembly comprises a saw blade and a workpiece, the motor is arranged in the machine body and used for driving the saw blade to rotate, and the machine body is connected to the bottom plate in a linearly movable mode through the connecting assembly.

The invention has the beneficial effects that: when the power tool is used by a user, the angle of holding the tool is kept unchanged, the holding direction does not need to be changed by the user, and the operation comfort of the user is improved. In addition, when a user uses the power tool to perform slotting operation in the middle of a workpiece, the motion trail of the saw blade is a straight line, so that the user can conveniently pre-judge the cutting position of the saw blade, and the operation difficulty and the experience and skill requirements of the operator are low. In addition, if the structure for indicating the cutting width is adopted to indicate the cutting position of the saw blade, the arrangement of the structure for indicating the cutting width is facilitated to be simplified.

Preferably, the connecting assembly comprises a fixing member fixedly connected to the body and at least one guide rail fixedly connected to the base plate, and the guide rail and the fixing member can move relatively.

Preferably, the guide rail is a guide pillar. The guiding performance is better.

Preferably, the guide rail is a cylindrical guide rail. Such an arrangement has the advantage of facilitating manufacture and assembly.

Preferably, the connecting assembly comprises two guide rails, and the two guide rails are arranged on the bottom plate at intervals.

Preferably, the plane formed by the axes extending lengthwise of the two rails is parallel to the plane of the saw blade. So set up for the structure is compacter, has reduced the size of instrument, makes the accessibility of instrument better.

Preferably, a linear bearing is arranged between at least one of the two guide rails and the fixing piece. The linear bearing is arranged between the two, so that the relative motion between the two is smoother, the locking of the mechanism is avoided, and the comfort level of user operation is improved.

Preferably, a linear bearing is arranged between the guide rail close to the front end of the two guide rails and the fixing piece.

Preferably, the direction of relative movement of the guide rail and the fixing member is inclined with respect to the base plate.

Preferably, the guide rail includes a first end fixedly connected to the bottom plate and a second end opposite to the first end, and the first end is located at the front side of the second end when the power tool is normally used for cutting.

Preferably, the angle between the axis of longitudinal extension of the guide rail and the base plate is 80 ° to 87 °.

Preferably, the angle between the lengthwise axis of the guide rail and the base plate is 82 °. So set up, can effectively prevent to produce the bounce in the course of the work, improve the comfort level and the security of user operation.

Preferably, the connecting assembly further comprises a restoring member, and the restoring member can restore the base plate to an initial state away from the fixing member after the base plate moves to a position close to the fixing member.

Preferably, one end of the guide rail is fixedly connected to the bottom plate, the other end of the guide rail penetrates through the fixing piece and is fixedly connected with an end cover, one end of the restoring piece abuts against the fixing piece, and the other end of the restoring piece abuts against the end cover; the guide rail includes first guide rail and second guide rail, first through-hole and second through-hole have been seted up to the mounting, first guide rail with the equal fixed connection of one end of second guide rail the bottom plate, first guide rail with the other end of second guide rail passes respectively first through-hole with second through-hole fixed connection the end cover, the recovery piece is located first guide rail with between the second guide rail.

Preferably, the end cover includes an end plate located on one side of the fixing member away from the bottom plate and an accommodating portion extending towards one side of the bottom plate, the fixing member includes a top plate close to the end plate, one end of the restoring member abuts against the top plate, and the other end abuts against the bottom of the accommodating portion.

Preferably, the guide rail with but the fixed part relative movement's direction is relative the bottom plate is perpendicular, first guide rail with first through-hole is thick location, the second guide rail with the second through-hole is the essence location, the fixed part with coefficient of static friction between the guide rail is fs, the fixed part with second guide rail complex length is H, the bottom plate is in first guide rail with keep away from on the line direction of second guide rail the tip of second guide rail with distance between the second guide rail is L, wherein, H >2 Lfs. So set up for guide rail mechanism can smoothly move, has avoided the locking of mechanism, has improved user operation's comfort level.

Preferably, the guide rail and the two ends matched with the through hole are respectively provided with a first sealing element and a second sealing element so as to isolate the through hole from the outside.

Preferably, the saw blade is located the first side of fuselage, coupling assembling is located the fuselage with the second side that first side is relative. So set up and avoided the sheltering from of guiding mechanism to the saw bit, the user of being convenient for observes the exact cutting position of saw bit when the operation, improves visuality to set up saw bit and coupling assembling and make the instrument focus be located the central plane of fuselage or be close to the central plane more in fuselage both sides, thereby make the user grip more comfortablely when the operation.

Preferably, the cutting assembly further comprises a lower shield and an upper shield, the lower shield is connected to the bottom plate and can move together with the bottom plate relative to the machine body, and the lower shield is arranged on one side of the saw blade close to the bottom plate so as to cover the saw blade; the connecting assembly can push the lower shield to move linearly relative to the machine body in a direction away from the bottom plate together with the bottom plate so as to expose a part of the saw blade; the upper shield is fixed relative to the machine body and covers one side of the saw blade, which is far away from the bottom plate, so that the upper shield and the lower shield together cover the whole saw blade; the coupling assembling is relative can drive when the fuselage removes lower guard shield is relative the fuselage stretches into or stretches out go up the guard shield.

Preferably, the body includes a front end for mounting the cutting assembly and a rear end remote from the front end, the motor is located at the rear end of the body, and an axis of a rotating shaft of the motor is perpendicular to an axis of a rotating shaft of the saw blade.

Preferably, when the power tool is normally used for cutting, the forward direction is forward, and when the machine body moves towards the bottom plate, the center of the saw blade moves forward relative to the bottom plate.

In order to solve the above problems, another technical solution of the present invention is: a power tool comprising a body, a cutting assembly and a connecting assembly; the cutting assembly is used for supporting the bottom plate on the surface of the workpiece when the cutting assembly comprises a saw blade and a workpiece, the motor is arranged in the machine body and used for driving the saw blade to rotate, and the machine body is connected to the bottom plate in a vertically movable mode through the connecting assembly.

In order to solve the above problems, another technical solution of the present invention is: a power tool comprising a body, a cutting assembly and a connecting assembly; the cutting assembly is used for supporting the bottom plate on the surface of the workpiece when the cutting assembly comprises a saw blade and a workpiece, the motor is arranged in the machine body and used for driving the saw blade to rotate, and the machine body is connected to the bottom plate in a linearly-inclined moving mode through the connecting assembly.

Drawings

FIG. 1 is a schematic structural view of one embodiment of a power tool of the present invention;

FIG. 2 is a perspective view of the power tool of FIG. 1 in an initial state;

FIG. 3 is a perspective view of the power tool of FIG. 1 in a cutting position;

FIG. 4 is a cross-sectional view of the coupling assembly of the power tool of FIG. 1 in two different states corresponding to FIGS. 2 and 3;

FIG. 5 is a cross-sectional view of the power tool shown in FIG. 2 taken along A-A;

FIG. 6 is a cross-sectional schematic view of the power tool connection assembly of FIG. 1;

FIG. 7 is a force analysis diagram of one embodiment of the power tool of the present invention;

FIG. 8 is a force analysis diagram of another embodiment of the power tool of the present invention;

FIG. 9 is a cross-sectional view of the power tool of FIG. 1;

FIG. 10 is a cross-sectional view of another angle of the power tool of FIG. 1;

FIG. 11 is a top view of the power tool of FIG. 1;

FIG. 12 is a side view of the power tool of FIG. 1;

FIG. 13 is a front view of the power tool of FIG. 1;

FIG. 14 is a top view of the power tool of FIG. 1 with the end cap hidden;

FIG. 15 is a front view of a power tool of another embodiment of the present invention;

FIG. 16 is a schematic view of the blade movement of the power tool of FIG. 1;

FIG. 17 is a schematic view of the blade movement of the power tool of FIG. 15;

wherein:

10 power tool 100 body 200 cutting assembly

300 connecting assembly 400 motor 202 saw blade

204 bottom plate 206 upper shield 208 lower shield

310 connecting piece 332 fixing 330 guide rail

314 endcap 316 endplate 318 receptacle

362 Top plate 320 screw 322 first seal

324 second seal 500 drive mechanism 520 first bevel gear

540 second bevel gear 560 Gear shaft 580 Gear

380 restoring member 210 hole 212 abutment surface

328a first rail lengthwise extension 328b second rail lengthwise extension 330a first rail

Axis line

330b second guide rail 332a first mount 332b second mount

106 fuselage axis 108 goes out dust exit 110 spindle lock

334a, b linear bearings 336a, b shaft sleeve 600 workpiece

h saw blade sinking amount w saw blade advancing amount l saw blade moving distance

s1 Back incision S2 front incision

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

Referring to fig. 1 and 2, in one embodiment of the invention, a power tool 10 includes a body 100, a cutting assembly 200 including a saw blade 202 for cutting a workpiece, a shoe 204 for abutting a surface of the workpiece when cutting the workpiece, and a linkage assembly 300. The main body 100 is provided with a motor 400 for driving the power tool 10, and in particular, the motor 400 is used for driving the saw blade 202 to rotate to cut a workpiece. The saw blade 202 is preferably a circular saw blade, and the saw blade 202 may be a grinding blade with abrasive grains, a saw blade with cemented carbide tips welded thereto, or a saw blade without cemented carbide tips. The motor 400 is accommodated in the body 100. The base plate 204 has an abutment surface 212 for abutment against a workpiece, and the base plate 204 is provided with a hole 210 through which the saw blade 202 passes when cutting. The forward direction X of the user when the user normally uses the power tool to cut is defined as the front direction, and the opposite direction is defined as the rear direction X'. The pressing direction Y of the user during normal use of the power tool for cutting is defined as the lower direction, and the opposite direction is defined as the upper direction Y'.

Referring to fig. 2, 3 and 4, wherein the solid line position of fig. 4 represents a cross-sectional view of the coupling assembly in an initial, i.e., rest, state of the power tool 10; the dashed line position represents a cross-sectional view of the coupling assembly when the power tool 10 is in the cutting state, i.e., in operation. 2-4, when a user desires to use the power tool 10, the base plate 204 is typically pressed against the workpiece to be cut and the body is pressed downward in the Y-direction so that the blade 202 passes through the hole 210 after the base plate 204 moves relative to the body, the blade 202 rotates to cut the workpiece to be cut under the drive of the motor 400, and the user can push the power tool 10 in the X-direction to cut the power tool forward. When the power tool 10 is not required to be used, the base plate 204 and the body 100 move in opposite directions to each other, and return to the initial state.

Referring to fig. 1, 2 and 3, the body 100 is linearly movably connected to the base plate 204 with respect to the base plate 204 by a connection assembly 300. Specifically, in the present embodiment, the main body 100 is vertically movably connected to the bottom plate 204 relative to the bottom plate 204 by the connection assembly 300, that is, the main body 100 is linearly movably connected to the bottom plate 204 in a direction perpendicular to the bottom plate 204 by the connection assembly 300. The base plate 204 may also be connected to the body 100 by the connecting assembly 300 to be linearly movable relative to the saw blade 202 in a direction substantially perpendicular to the base plate 204. In use of the power tool 10, the base plate 204 is typically pressed against a workpiece to be cut, and the body 100 moves relative to the base plate 204 during the pressing process. The connecting assembly 300 includes a fixing member 332 and a connecting member 310. The fixing piece and the connecting piece can move relatively. Connector 310 includes at least one rail 330 fixedly attached to base plate 204 and end cap 314, rail 330 and fastener 332 being movable relative to each other. In the present embodiment, the guide rail 330 includes two guide rails, a first guide rail 330a and a second guide rail 330 b. Preferably, the guide rail is a cylindrical member. One end of the first and

second guide rails

330a, 330b is fixedly connected to the bottom plate 204, and the first and

second guide rails

330a, 330b are spaced apart from each other on the bottom plate 204. The fixing

members

332a and 332b are fixedly connected to the body 100, the fixing member may be a combination of a plurality of components or may be a single component formed integrally, in this embodiment, the portion of the hole structure engaged with the first guide rail 330a is the first fixing member 332a, and the portion engaged with the hole structure of the second guide rail 330b is the second fixing member 332 b. Of course, it is also possible that the fixing element comprises a hole-like structure and is arranged on the base plate, while the guide rail is a column arranged on the machine body. First rail 330a and first mount 332a are guided in coaxial engagement with one another along first rail's lengthwise extending axis 328a and are movable relative to one another along axis 328 a. The second rail 330b and the second mount 332b are guided in coaxial engagement with each other along a second rail's lengthwise extending axis 328b and are movable relative to each other along the axis 328 b. And the first rail lengthwise extension axis 328a and the second rail lengthwise extension axis 328b are parallel to each other. In addition, the direction of relative movement of both the body 100 and the base plate 204 is also parallel to the lengthwise extending axes of the two rails. Specifically, in the present embodiment, the first guiding rail 330a passes through the first fixing member 332a, and the second guiding rail 330b passes through the second fixing member 332 b. In addition, in the present embodiment, the connection assembly 300 further includes an end cap 314 fixedly connected to the first and

second guide rails

330a and 330 b. The first guide rail 330a is fixedly connected to the end cap 314 after passing through the first fixing member 332a, and the second guide rail 330b is fixedly connected to the end cap 314 after passing through the second fixing member 332 b. End cap 314 includes an end plate 316 on the side of fastener 332 away from base plate 204. Specifically, the first and

second rails

330a, 330b are fixedly connected to the end plate 316 of the end cap, and preferably, the rails are fixedly connected to the end plate 316 by screws 320. Although the embodiment uses the first and second guide rails and the first and second fixing members to guide each other, it is also possible to use only one guide rail and only one fixing member to guide each other. The use of two guide rails can of course greatly increase the stability of its movement. And end cap 314 prevents the fastener and rail from disengaging from each other. In this embodiment, the

guide rails

330a, 330b are preferably guide posts, and more preferably cylindrical guide rails. So set up, its guidance quality is more, and be convenient for processing and assembly.

Referring to FIG. 1, in one embodiment, the cutting assembly 200 further includes a lower shroud 208 and an upper shroud 206, the lower shroud 208 being coupled to the base plate 204, the lower shroud 208 being movable with the base plate 204 relative to the fuselage 100. The lower guard 208 covers the side of the blade 202 near the bottom plate 204 to cover the blade 202. The lower shroud 208 is located on a first side of the airframe 100 along with the saw blade 202. The linkage assembly 300, in conjunction with the base plate 204, may urge the lower shroud 208 to move linearly relative to the body 100 in a direction away from the base plate 204 to expose a portion of the saw blade 202. The lower guard 208 is provided to better protect the saw blade 202 and prevent the saw blade 202 from exposing the bottom plate 204 to harm the human body.

An upper guard 206 is fixed relative to the body 100, and the upper guard 206 covers the side of the blade 202 remote from the shoe 204, thereby covering the entire blade 202 with a lower guard 208. Referring to fig. 5, the saw blade 202, the lower guard 208, and the upper guard 206 of the cutting assembly 200 are disposed on a first side of the body 100. The connecting assembly 300 moves relative to the fuselage 100 to move the lower shroud 208 relative to the fuselage 100 into and out of the upper shroud 206. The upper guard 206 further protects the saw blade 202 from other objects that may damage the saw blade 202 covered by the upper guard 206, as well as from human injury from the saw blade 202.

As shown with reference to fig. 5 and 6, the connection assembly 300 further includes a return member 380. The restoring member 380 may provide a resilient force to move the base plate 204 and the body 100 away from each other when the power tool 10 is restored from the cutting state to the initial state, i.e., the base plate 204 may restore the base plate 204 to the initial state away from the fixing member 332 after the base plate 204 is moved to a position close to the fixing member 332. In this embodiment, the restoring element 380 is disposed between the fixing element 332 and the connecting element 310, and one end of the restoring element abuts against the fixing element 332 and the other end abuts against the connecting element 310. Specifically, between end cap 314 and fastener 332. Preferably, return 380 is a compression spring. In this embodiment, the fixture has a top plate 362 adjacent the end plate 316. End cap 314 includes a receptacle 318 extending toward the side of base plate 204. Restoring member 380 abuts top plate 362 at one end and the bottom of receptacle 318 at the other end. And the top plate 362 of the fixing member is movable up and down in the space formed by the accommodating portion 318 and the end plate 316. The top plate 362 and the end plate 316 abut against each other by the restoring member 380, i.e., the end cap 314 and the fixing

members

332a, 332b abut against each other when the power tool 10 is in the initial state shown in fig. 2. When the user cuts a workpiece, the power tool 10 is in the cutting state shown in fig. 3, and the user presses down on the body, and during the relative movement between the base plate 204 and the body 100, the fixed member 332 fixedly connected to the body moves down relative to the base plate 204, and the top plate 362 of the fixed member presses down on the restoring member 380, so that the restoring member 380 is compressed, and the guide rail and the fixed member move relative to each other along the longitudinal extension axis of the guide rail for guidance. When the user stops cutting the workpiece and starts to retract the power tool 10, the restoring force of the restoring member 380 pushes the base plate 204 and the body 100 to move in opposite directions to return to the original positions, so that the automatic reset is realized.

Referring to fig. 12, in this embodiment, the connecting assembly 300 further includes at least one linear bearing, and the linear bearing is disposed between the guide rail and the fixing member, that is, the linear bearing is disposed between at least one fixing member of the two guide rails, that is, the linear bearing is disposed between the first guide rail 330a and the first fixing member 332a and/or between the second guide rail 330b and the second fixing member 332 b. In the present embodiment, the linear bearing 334a is disposed between the first guide rail 330a and the first fixing member 332 a. Of course, it is also possible to dispose the linear bearing 334b between the second guide rail 330b and the second fixing member 332 b. Preferably, the linear bearing is disposed between the guide rail near the front end and the fixed member. The linear bearing is additionally arranged between the guide rail and the fixing piece, so that the relative motion between the guide rail and the fixing piece is smoother, the mechanism is prevented from being locked, and the comfort level of user operation is improved. In this embodiment, the fixing member 332 is provided with a first through hole and a second through hole, and a portion of the fixing member including the first through hole is the first fixing member 332a, and a portion of the fixing member including the second through hole is the second fixing member. One end of each of the first guide rail 330a and the second guide rail 330b is fixedly connected to the bottom plate 204, the other end of each of the first guide rail 330a and the second guide rail 330b passes through the first through hole and the second through hole respectively to be fixedly connected to the end cap 314, and the restoring member 380 is located between the first guide rail and the second guide rail. The distance between the first guide rail 330a and the rotational axis of the blade 202 is substantially equal to the distance between the second guide rail 330b and the rotational axis of the blade 202. Referring to fig. 4, in the present embodiment, a first sealing member 322 and a second sealing member 324 are respectively disposed at two ends of the guide rail, which are engaged with the through hole, to isolate the through hole from the outside. The sealing rings are arranged at the two ports of the through hole, the matching area of the guide rail and the through hole is sealed, the through hole is isolated from the outside, and the influence on the matching between the guide rail and the fixing piece when chips enter the through hole in the cutting process is prevented.

Referring to fig. 7 and 8, the first guide rail is engaged with the first through hole and the second guide rail is engaged with the second through hole, one of which is a coarse positioning and the other is a fine positioning. In this embodiment, the guide rail and the through hole that are engaged with each other are sliding friction in the case of coarse positioning, and the guide rail and the through hole that are engaged with each other are rolling friction in the case of fine positioning, and the clearance in the coarse positioning is larger than that in the fine positioning. In the embodiment shown in fig. 7, a bushing 336a is arranged between the first guide rail 330a and the second fixing member 332a for coarse positioning, the second guide rail 330b and the second fixing member 332b are precisely positioned by the linear bearing 334b, the static friction coefficient between the second fixing member 332b precisely positioned by the linear bearing 334b and the second guide rail 330b is fs, the length of the second fixing member 332b engaged with the second guide rail 330b is H, the distance between the end of the bottom plate 204 far from the second guide rail 330b in the connecting line direction of the first guide rail and the second guide rail is L, and fs, H, and L satisfy the following relations: h >2 Lfs. In the embodiment shown in fig. 8, however, the first guide rail 330a and the first fixing member 332a are precisely positioned by the linear bearing 334a, and the second guide rail 330b and the second fixing member 332b are coarsely positioned by the bushing 336 b. The static friction coefficient between the first fixed member 332a and the first guide rail 330a precisely positioned by the linear bearing 334a is fs, the length of the first fixed member 332a engaged with the first guide rail 330a is H, the distance between the end of the bottom plate 204 distant from the second guide rail 330b in the direction of the line connecting the first guide rail and the second guide rail 330b is L, and the above parameters fs, H, L satisfy the following relationship H >2 Lfs.

In the embodiment shown in fig. 7, the first guide rail 330a and the first fixing member 332a on the left side are roughly positioned by the bushing 336a along the previously defined direction X. The fitting clearance between the roughly positioned first guide rail 330a and the first fixing member 332a is large, that is, the fitting clearance between the first guide rail and the first through hole is large. When the base plate 204 is stressed, the coarsely positioned first rail 330a is not stressed when deflected. The second guide rail 330b and the second fixing member 332b on the right side are precisely positioned through the linear bearing 334b, the fit clearance between the precisely positioned second guide rail 330b and the second fixing member 332b is small, that is, the fit clearance between the second guide rail and the second through hole is small, and when the bottom plate 204 is stressed, the precisely positioned second guide rail 330b is stressed when deflected. When cutting the workpiece, the force F of the workpiece on the bottom plate 204 is applied to the end of the bottom plate 204 close to the first guide rail 330a, and L is the distance between the force applied to the bottom plate 204 and the second guide rail 330b, i.e. the distance between the end of the bottom plate 204 far from the second guide rail 330b to the second guide rail 330 b.

In the embodiment shown in fig. 8, the second guide rail 330b and the second fixing member 332b on the right side are roughly positioned by a bushing 336b along the previously defined direction X. The fit clearance between the coarsely positioned second guide rail 330b and the second fixing member 332b is large, that is, the fit clearance between the second guide rail and the second through hole is large. When the bottom plate 204 is stressed, the coarse positioning second guide rail 330b is not stressed when deflected. The first guide rail 330a and the first fixing member 332a on the left side are precisely positioned by the linear bearing 334a, and the fit clearance between the precisely positioned first guide rail 330a and the first fixing member 332a is small, that is, the fit clearance between the first guide rail and the first through hole is small. When the base plate 204 is stressed, the finely positioned first rail 330a is stressed as it deflects. When the workpiece is cut, a force point of a force F of the workpiece on the bottom plate 204 is at one end of the bottom plate 204 close to the coarsely-positioned second guide rail 330b, and L is a distance between the force point of the bottom plate 204 and the finely-positioned first guide rail 330a, that is, a distance between one end of the bottom plate 204, which is far away from the finely-positioned first guide rail 330a in the direction X, and the finely-positioned first guide rail 330 a.

Specifically, when the first guide rail and the second guide rail are respectively matched with the fixing member through the first through hole and the second through hole to provide a thrust facing the saw blade 202 to the force bearing point of the guide rail near the coarse positioning of the bottom plate 204, fs, H, and L should satisfy the above relationship in order to enable the guide rails to move smoothly.

When cutting, with bottom plate 204 atress slope, the stress point of bottom plate 204 supports and pushes down by the cutting work piece, and bottom plate 204 receives perpendicular bottom plate 204 ascending thrust F, and the guide rail of smart location can receive full confining force respectively with the through-hole complex both ends of mounting, and the stress point of the guide rail of smart location is A point and B point respectively, and full confining force is FRA and FRB respectively. The full constraint force is the resultant force of the reaction force and the static friction force of the through hole of the fixed part matched with the guide rail on the precisely positioned guide rail. When the precisely positioned guide rail is at the critical balance point, the static friction force borne by the precisely positioned guide rail reaches the maximum value, and at the moment, the included angle between the full constraint force and the reaction force is also the maximum value, and the included angle is the friction angle phi. When the included angle between the action lines of the full constraint force and the reaction force reaches the friction angle phi, the action lines of the two full constraint forces are intersected at the point C, the length between the point C and the precisely positioned guide rail is the critical length L1, at this time, L1 equals H plus cot phi/2, cot phi represents the cotangent value of the friction angle phi, the static friction coefficient fs is the tangent value of the friction angle phi, and L1 equals H/2 fs. Because the included angle between the action lines of the full constraint force and the reaction force can only be within the friction angle phi, the action lines of the two full constraint forces can only be intersected in a C point or a shadow area of the guide rail far away from the precise positioning formed after the action lines are intersected. According to the three-force balance convergence condition, the precisely positioned guide rail can be balanced only when the thrust and the two constraint forces meet at one point, so that when the L < L1, namely H >2Lfs, the thrust F and the two constraint forces cannot converge, the three forces cannot reach balance, the precisely positioned guide rail cannot be clamped, and the precisely positioned guide rail can move only by using a small thrust F. That is to say, when satisfying above-mentioned condition, guide rail and mounting can not die by the card, and the user can be more smoothly comfortable when operating this power tool.

Referring to fig. 9, in one embodiment, the motor 400 is located at the rear end of the body 100, and the rotational axis of the motor 400 is perpendicular to the rotational axis of the saw blade 202.

Specifically, the motor 400 is coupled to a rotational shaft of the saw blade 202 through a transmission mechanism, the transmission mechanism 500 includes a first bevel gear 520, a second bevel gear 540, a gear shaft 560, and a gear 580, a shaft of the first bevel gear 520 is coupled to the rotational shaft of the motor 400 through a coupling (not shown), teeth of the first bevel gear 520 are engaged with teeth of the second bevel gear 540 to transmit power to a vertical direction, and the gear shaft 560 is fixedly coupled to an output shaft of the second bevel gear 540 and engaged with the gear 580 to transmit power to the rotational shaft of the saw blade 202. Thus, the power of the motor 400 is transmitted from the rear end to the front end of the body 100, and the rotational axis of the motor 400 is perpendicular to the rotational axis of the saw blade 202.

Referring to fig. 10-12, in one embodiment, the saw blade 202 is positioned on a first side of the body 100 and the linkage assembly 300 is positioned on a second side of the body 100 opposite the first side. Referring to FIG. 11, the power tool 10 has a central plane, and in this embodiment, the body 100 has an elongated axis 106, and the plane passing through the body axis 106 and perpendicular to the base plate 204 is the central plane. The linkage assembly 300 and the saw blade 202 are located on either side of the central plane. Because the saw blade 202 and the connecting assembly 300 of the cutting assembly 200 are respectively located at two opposite sides of the body 100, in the process of cutting by using the cutting assembly 200, the connecting assembly 300 does not influence an operator to observe the cutting of the cutting assembly 200 to an object, namely, the sight of the operator is not shielded, the cutting visibility is better, the saw blade and the connecting assembly are arranged at two sides of the central plane, so that the gravity center of the tool is located at the central plane or is closer to the central plane, and therefore, a user can hold the tool more comfortably during operation.

In one embodiment, the body 100 includes a front end for mounting the cutting assembly 200 and a rear end away from the front end, and the body 100 includes a left side and a right side as viewed from the rear end to the front end of the body 100, and preferably, the cutting assembly 200 is located on the left side and the connecting assembly 300 is located on the right side. Since most operators are right handed, with the cutting assembly 200 on the left, the saw blade 202 contained within the cutting assembly 200 is positioned directly in the operator's field of view during operation, further enhancing the visibility of the power tool 1000.

Referring to FIG. 13, in this embodiment, the planes defined by the lengthwise extending

axes

328a, 328b of the two

rails

330a, 330b are parallel to the plane defined by the blade 202. The arrangement makes the structure more compact, reduces the size of the power tool and makes the accessibility of the power tool better.

Referring to fig. 13, in the present embodiment, the dimension of the connecting assembly 300 in the direction X is smaller than the dimension of the saw blade 202 in the direction, further, the front end of the connecting assembly 300 does not exceed the front end of the saw blade 202, and the rear end of the connecting assembly 300 does not exceed the rear end of the saw blade 202. So set up, coupling assembling can not cause the saw bit to shelter from, and the user can observe the saw bit cutting position around the cutting process, has improved visuality.

Referring to fig. 13, in the present embodiment, the power tool 10 further includes a dust outlet 108, and the dust outlet 108 is preferably provided at the front end of the hood portion. At least one of the guide rails is located between the dust outlet 108 and the axis of the saw blade 202, and in this embodiment, the second guide rail 330b is located between the dust outlet 108 and the center of the saw blade.

Referring to fig. 13, in the present embodiment, the power tool 10 further includes a spindle (not shown) for mounting the saw blade 202 and driving the saw blade 202 to rotate, and a spindle lock 110 for locking the spindle from rotating, when a user needs to replace the saw blade, the spindle can be prevented from rotating by locking the spindle lock 110, so as to avoid a safety hazard caused by the user starting the tool by mistake. In this embodiment, the spindle lock 110 is positioned between two

track mechanisms

326a, 326 b. As further shown in fig. 14, the maximum perpendicular distance of the spindle lock 110 to the center plane is less than the maximum perpendicular distance of the first and

second securing members

332a, 332b to the center plane. That is, the outermost end of the spindle lock 110 does not extend beyond the outermost end of the connecting assembly, and when the user does not need to lock the spindle lock, the spindle lock is not easily operated by the user due to the blocking of the guiding mechanism.

Referring to FIG. 15, another embodiment of the present invention is shown. This embodiment is substantially the same as the previous embodiment except that the body 100 is connected to the base plate 204 by a connecting member 300 to be linearly movable obliquely relative to the base plate 204, and specifically, the direction of the relative movement between the guide rail and the fixing member is inclined to the base plate 204. That is, the lengthwise extending

axes

328a, 328b of the guide rails are both disposed obliquely with respect to the base plate 204 and are parallel to each other. Referring to fig. 16, the

longitudinally extending axes

328a, 328b of the guide rails are both inclined rearwardly with respect to the aforementioned direction X, i.e. the lower the longitudinally extending axis of the guide rail is in the aforementioned direction Y, the further forward it is in the aforementioned direction X; that is, one end of the guide rail 330 fixedly connected to the bottom plate 204 is a first end, and the other end opposite to the first end is a second end, and the first end is located at the front side of the second end; that is, when the body 100 moves toward the base plate 204, the center of the saw blade 202 moves forward relative to the base plate 204. Preferably, the angle α between the lengthwise extending

axes

328a, 328b of the rails and the base plate 204 is 80 ° to 87 °. More preferably, the angle α between the lengthwise extending

axes

328a, 328b of the rails and the base plate 204 is 82 °. So set up, can effectively prevent to produce the bounce in the course of the work, improve the comfort level and the security of user operation.

Fig. 16 is a schematic view of the movement of the saw blade in the embodiment of fig. 1, in which the axis of longitudinal extension of the guide rails is perpendicular to the plane of the base plate. Fig. 17 is a schematic view of the movement of the saw blade in the embodiment of fig. 15, in which the lengthwise extending axis of the guide rail is inclined with respect to the plane of the base plate. Referring to fig. 16 and 17, the rotational direction R of the saw blade 202 causes the saw blade 202 to move upward in the forward portion of the cutting direction X and downward in the rearward portion of the cutting direction X. Thus, when the rearward portion of the blade 202 suddenly rotates at high speed and cuts down into the workpiece 600, the momentary increase in resistance of the workpiece 600 against the blade 202 tends to cause tool bounce which can cause operator discomfort and reduced safety, and can also easily damage the workpiece or cause cutting inaccuracies. Comparing fig. 16 and 17, it can be seen that in the embodiment where the lengthwise extending axis of the guide rail is disposed perpendicular to the bottom plate when the user presses the tool and the saw blade is sunk by the same distance h, the saw blade has no forward movement, while in the embodiment where the lengthwise extending axis of the guide rail is disposed inclined with respect to the bottom plate, the saw blade has a forward movement w. Further, the former has no forward movement amount, so the blade rear cut amount s1 and the front cut amount s2 are equal, while the latter has a significantly reduced blade rear cut amount s2 and a significantly increased front cut amount s 1. In addition, when the blade moving distance l is the same, the latter blade sinking amount h is smaller than the former blade sinking amount h, and thus when the user pushes down the blade using the same speed, the latter blade sinking speed is also smaller than the former blade sinking speed. The rebound phenomenon is mainly generated because the rear part of the saw blade is blocked from cutting into a workpiece, so that the longitudinal extending axis of the guide rail is obliquely arranged relative to the bottom plate, the rear cutting amount of the saw blade is reduced, the sinking speed of the saw blade is reduced, and the rebound phenomenon can be effectively improved.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A power tool comprising a body, a cutting assembly and a connecting assembly; cutting assembly is used for leaning on workpiece surface's bottom plate when being used for cutting the saw bit of work piece and cutting the work piece, be equipped with the motor in the fuselage, the motor is used for the drive the saw bit is rotatory, the fuselage passes through coupling assembling is relative but bottom plate rectilinear movement ground is connected to the bottom plate, normal use the direction that advances when power tool cuts is preceding, works as the fuselage orientation when the bottom plate removes, the center of saw bit is relative the bottom plate moves forward.

2. The power tool of claim 1, wherein: coupling assembling include fixed connection in the mounting of fuselage and at least one fixed connection in the guide rail of bottom plate, the guide rail with mounting relative movement.

3. The power tool of claim 2, wherein: the guide rail is a guide pillar.

4. The power tool of claim 2, wherein: the connecting assembly comprises two guide rails, and the two guide rails are arranged on the bottom plate at intervals.

5. The power tool of claim 4, wherein: and a linear bearing is arranged between at least one of the two guide rails and the fixing piece.

6. The power tool of claim 2, wherein: the direction of relative movement of the guide rail and the fixing piece is inclined relative to the bottom plate.

7. The power tool of claim 6, wherein: the guide rail including fixed connection in the first end of bottom plate, with the second end that first end is relative, normal use the direction that advances when power tool cuts is preceding, first end is located the front side of second end.

8. The power tool of claim 2, wherein: the connecting assembly further comprises a restoring piece, and the restoring piece can enable the bottom plate to be restored to an initial state far away from the fixing piece after the bottom plate moves to a position close to the fixing piece.

9. The power tool of claim 8, wherein: one end of the guide rail is fixedly connected to the bottom plate, the other end of the guide rail penetrates through the fixing piece and is fixedly connected with an end cover, one end of the restoring piece abuts against the fixing piece, and the other end of the restoring piece abuts against the end cover; the guide rail includes first guide rail and second guide rail, first through-hole and second through-hole have been seted up to the mounting, first guide rail with the equal fixed connection of one end of second guide rail the bottom plate, first guide rail with the other end of second guide rail passes respectively first through-hole with second through-hole fixed connection the end cover, the recovery piece is located first guide rail with between the second guide rail.

10. The power tool of claim 9, wherein: the end cover comprises an end plate and an accommodating part, the end plate is located on one side, far away from the bottom plate, of the fixing part, the accommodating part extends towards one side of the bottom plate, the fixing part comprises a top plate close to the end plate, one end of the restoring part abuts against the top plate, and the other end of the restoring part abuts against the bottom of the accommodating part.

11. The power tool of claim 9, wherein: the guide rail with but mounting relative movement's direction is relative the bottom plate is perpendicular, first guide rail with first through-hole is thick location, the second guide rail with the second through-hole is smart location, the mounting with coefficient of static friction between the guide rail is fs, the mounting with second guide rail complex length is H, the bottom plate is in first guide rail with keep away from on the line direction of second guide rail the tip of second guide rail with distance between the second guide rail is L, wherein, H >2 Lfs.

12. The power tool of claim 9, wherein: the guide rail with through-hole complex both ends are equipped with first sealing member and second sealing member respectively, in order to keep apart through-hole and external world.

13. The power tool of claim 1, wherein: the saw bit is located the first side of fuselage, coupling assembling is located the fuselage with the second side that first side is relative.

14. The power tool of claim 1, wherein: the cutting assembly further comprises a lower shield and an upper shield, the lower shield is connected to the bottom plate and can move together with the bottom plate relative to the machine body, and the lower shield is arranged on one side, close to the bottom plate, of the saw blade so as to cover the saw blade; the connecting assembly can push the lower shield to move linearly relative to the machine body in a direction away from the bottom plate together with the bottom plate so as to expose a part of the saw blade; the upper shield is fixed relative to the machine body and covers one side of the saw blade, which is far away from the bottom plate, so that the upper shield and the lower shield together cover the whole saw blade; the coupling assembling is relative can drive when the fuselage removes lower guard shield is relative the fuselage stretches into or stretches out go up the guard shield.

15. The power tool of claim 1, wherein: the fuselage is including the installation cutting assembly's front end and keeping away from the rear end of front end, the motor is located the rear end of fuselage, the axis perpendicular to of the axis of rotation of motor the axis of rotation of saw bit.

16. A power tool comprising a body, a cutting assembly and a connecting assembly; the cutting assembly is used for supporting the bottom plate on the surface of the workpiece when the cutting assembly comprises a saw blade and a workpiece, the motor is arranged in the machine body and used for driving the saw blade to rotate, and the machine body is connected to the bottom plate in a linearly-inclined moving mode through the connecting assembly.