Vibration absorber, use this vibration absorber instrument and the cleaning surface of the work method
Technical field
The present invention relates to a kind of portable power tool that acts on the working face surface.Particularly relate to a kind of vibration absorber that is applied to eccentric rotary oscillation class instrument, especially sander and polishing machine.The present invention relates to the eccentric rotary oscillation class instrument that uses similar vibration absorber equally, and the method on eccentric rotary oscillation class tool grinding polishing workpiece surface
Background technology
As everyone knows, eccentric rotary oscillation class instrument as frosted class instrument, generally includes a base plate or liner and supports an abrasive body, as sand paper.Liner is connected on the motor by the suitable kind of drive, and motor is installed on the casing that has one or more handles.The kind of drive is embodied in the rotation of motor shaft driving cam.Cam is to be installed on the circular hole that is arranged in pad centers.Each o'clock on the rotation driving liner of cam, the radius of this circular trace equaled the eccentric throw of cam along the orbiting motion of a circle, and just the center line of motor shaft is to the distance at the circular hole center that is positioned at the pad centers that supports abrasive body.Because allow the center rotation of liner around circuit orbit, this compound swing-around trajectory also can be called as " free orbit ".
Often, described orbiting motion can be counted as the linear movement that cushion body quickens on certain orientation.This acceleration has produced rightabout reaction force.The unnecessary vibration that reaction force produces is delivered to fuselage and finally is delivered to operator's hand and arm.The amplitude of this vibration depends on the diameter dimension of track and the ratio of liner quality and machine quality.The operator of these machines generally can apply certain power or load to machine and go to accelerate operating rate and increase productivity, but tends to increase the amplitude of vibration like this.
For vibration limiting an acceptable level, the diameter of working face of available on the market machine, equipment and electric tool (size of liner) and track often is designed to be relative less.Yet this restriction has reduced the efficient of machine.
In order to remedy this restriction to efficient, the operator tends to machine is applied certain load to increase the frictional force on the working face.But do like this and cause vibration to strengthen further.The operator has to apply bigger power again for the vibration of eliminating this increase and goes machine by on workpiece.So, the quality of machine is actually and has increased, and vibration is that the person's of being operated hand and arm absorbed, and this can produce serious consequence to health of operator.
Even those use the people of frosted class instrument also can realize the numbness and the shouting pain of finger, arm and arm very soon once in a while.These symptoms will display after few minutes of operation, make us feeling very unhappy, and the sensation of this numbness and shouting pain also continues several hrs behind terminating operation.If the ongoing operation several hrs then will be taken several days time and recover.This vibration is more serious to the consequence that the workman causes.
The disease that the workman causes owing to the long-term vibration that contacts electric tool and equipment can make workman's retirement greatly, and this can cause high social cost.On the other hand, the index that the coupled vibration limiting value is adopted can have significant impact to productivity and product cost.
In sum, clearly, be that the producer of these electric tools that vibration is arranged or user wish to eliminate or reduce and be delivered to operator's vibration on one's body, thereby improve workman's safety and productivity and reduce relevant social cost.
The first method that addresses the above problem is, takes the relative liner of one or more eccentric bodies or balance weight to move in the other direction, thus balance vibration.Patent US 4,660,329, and US 4,729,194, and US 5,888,128, US 6,244,943, US6,206,771, US 2001/0003087, and DE 3922522, and EP 0303955, and EP 0455618, and WO 98/01733, this just solution that WO02/068151 disclosed.
In general, this solution can not play good effect when liner does not also touch workpiece, but significant limitation is but arranged in daily operation.Abrasive body on liner touches workpiece, and in fact load can change the quality of liner itself, thereby the ratio of liner quality and balance weight quality is also in variation.Therefore, balance weight can not be eliminated the vibration of the actual increase generation of liner quality.Load is big more, system is uneven more, vibrates big more.When load is tending towards infinitely great, liner will be stagnated and fuselage will be to equal the amplitude vibration of liner tracks radius.
Mandatory declaration be to use the operator of this type electric tool all to like instrument is applied certain load to improve operating rate.By imposed load operating efficiency being significantly improved, mainly is because the frictional force between liner and workpiece increases.On the other hand, therefore the increase of load makes the machine imbalance has also increased unnecessary vibration.Deduct the diameter of this unnecessary vibration from the race way diameter of liner, what therefore it is contemplated that is that effectively the diameter of working track is the race way diameter that theoretic race way diameter deducts this unnecessary vibration.
The second method that addresses the above problem is to adopt elastomeric material as the interface between machine and operator's the hand, thereby the kinetic energy of vibration is converted into the purpose that heat energy reaches the elimination vibration.Patent US 4,905,772, and US 5,453,577, US5,347,764, this just solution that US 2001/0011856 A1, WO 03/049902 are disclosed.Yet second kind of solution do not have realistic meaning.By insert elastic component between fuselage and staff, the amplitude of this electric tool is big when holding this instrument with a firm grip more than the operator.In fact, the operator feels that very naturally the operating efficiency of machine descends, and the power that tends to Hua Gengda for the operating efficiency operator who returns to hope goes to firmly grasp it.So, the effect that adds elastic component just has been minimized, so that vibration still is delivered to operator's arm and arm.In addition, the muscle of this increase is stressed can to reduce the ability that human body self is eliminated vibration, thereby causes even more serious consequence.
Disclosed a kind of sander among the open JP2002233941A of Japan's special permission, be parallel to the gear that output shaft is provided with by two of motor-driven.Two sanding dishes are separately positioned on the eccentric shaft by gear driven, and carry out orbital motion under the effect of rubber sleeve.The axis and the electrical axis of the orbital motion of two sanding dishes be arranged in parallel.Because two sanding dishes are symmetrical arranged with respect to motor shaft, can reduce vibration to a certain extent, but have remaining moment of torsion respectively in two sanding dishes, entire machine still produces the vibration of pendulum model.
Summary of the invention
Technical problem to be solved by this invention mainly provides a kind of vibration absorber and makes electric tool adapt to any working environment and keep high efficiency to overcome the problems referred to above and defective.
Another technical problem to be solved by this invention provides the amplitude that a kind of vibration absorber reduces to transmit from instrument the vibration of human body greatly, thereby reduces operator's health risk.
Another special technique problem to be solved by this invention provides a kind of cheap, maneuverable, vibration absorber of being convenient to safeguard for instrument.
Equally, the present invention also provides a kind of method that can not produce the buffing work-piece of extra vibration to the operator.
Another technical problem that the present invention solves provides a kind of portable power tool, particularly a kind of sander or polishing machine that has vibration absorber, make the user no matter roughly grind or finish grind and to keep high efficiency and productivity ratio which kind of material, no matter work as the user simultaneously and apply much load to this electric tool, can both sizable minimizing affact operator's vibration on one's body.
The technical scheme that is adopted that the present invention solves the problems of the technologies described above is,
By eccentric rotary oscillation class instrument, as polishing machine, especially realize by vibration absorber by installing on motor shaft rotation machine driven for this class of sander, it is characterized in that:
A) first surface and the first pre-first directed liner are arranged,
B) second surface and the second pre-second directed liner are arranged,
Abrasive body such as polished part or sand paper stick on first surface and second surface position,
And roughly align on same plane in described surface,
C) described first, second liner motion mode is to make it carry out along the track rotation around same center line respectively, and the rotation of described track is an out-phase.
The liner of dull and stereotyped sand remains essentially in predetermined direction.
Be the vibration absorber power compensation inertia and the frictional force of mandatory declaration has reduced the vibration that is delivered on the motor shaft.Such vibration must remain on a low level or or even compensated fully.
Based on this design, the function of vibration damping equipment no longer depends on the speed of rotation, the weight of machine, the type of lapped face, the radius of liner rotation and the condition of load.
Owing to cancelled the use of conventional balanced piece, made more energy can be used to grinding work.
Even load not by the situation of mean allocation to the lapped face under, the vibration surplus that is delivered to the operator from electric tool also will be lower than the conventional tool that has balance weight mechanism.
The working surface of each liner all is very smooth and is positioned at same plane.And one of them face is placed in the middle, and other face is in the periphery of this face.
In one embodiment, middle liner is circular, and peripheral liner is an annular.Certainly, liner also can be square, and four or polylith are more arranged.
A kind of device preferably that drives the liner motion is to comprise the eccentric block assembly of the cam formation at 180 ° of angles of identical, the vertical conversion of at least one pair of shape.Each cam must directly or indirectly be installed on the motor shaft.The cylindricality of each cam is identical, and the diameter of the desired just track that obtains of eccentric throw of the center line of the relative motor shaft of this cylindricality.
The external diameter of inner circular pads is slightly less than the internal diameter of outside ring liner, makes to be reserved with a minimum clearance in operating process between inside and outside liner.So, can be connected on a kind of aspirator,, remove chip and dust on the workpiece as fan in the gap between liner.This is equivalent to the dust export on the conventional machines.
According to the present invention, a kind of driving by motor shaft has the first pre-first directed liner and has the second pre-second directed liner to act on the method for workpiece, second liner rotates around second axis described first liner around first axle rotates, and this first axle and second axis overlap.
Two liners of dull and stereotyped sand keep their predetermined directions.
This in an embodiment method may be by additional feature:
A) use first liner of annular and second liner of circle, described second liner is the inside that is placed on first liner,
B) central axis of second liner rotates around the motor shaft center line, and
C) central axis of first liner rotates around the motor shaft center line on same direction of rotation, but departs from about 180 ° of the central axis of second liner.
According to the present invention, a kind of portable eccentric rotary oscillation class instrument, particularly polishing machine or sander comprise:
A) have the casing that the operator uses handle,
B) inner chamber of casing,
C) be installed in the motor in the chassis cavity and the motor shaft of longitudinal rotating shaft line is arranged,
D) at least one connects first liner of first abrasive body, with second liner that is connected second abrasive body and
E) energy transmission device from the motor shaft to the liner and as the described vibration absorber of preceding and attached claim.
This eccentric rotary oscillation class instrument can be designed to " circle sand machine ".
In order to compensate or to cancel moment of torsion, electrically powered machine can use the balance weight that directly or indirectly is connected on motor shaft or the fan, and the barycenter of balance weight is not on the motor shaft center line.
According to another embodiment, when using jockey, during the connector done as elastomeric material, eccentric rotary oscillation class instrument also can be designed as " dull and stereotyped sand ".
For fear of when liner is unloaded, rotating at a high speed, should use brake apparatus.
Description of drawings
In conjunction with the accompanying drawings, the detailed description of the vibration absorber specific embodiment of portable power tool is made that other feature and advantage of the present invention are more obvious.In figure below:
Fig. 1 is a partial sectional view of using " the circle sand machine " of vibration absorber of the present invention.
Fig. 2 is the three-dimensional exploded view of the vibration absorber shown in Fig. 1.
Fig. 3 is the decomposing section of the vibration absorber shown in Fig. 1.
Fig. 4 is the scaled down upward view of the vibration absorber shown in Fig. 1-3.
Fig. 5 is the profile after the vibration absorber assembling shown in Fig. 1-3.
Fig. 6 is the stereogram of the double cam assembly that uses in the vibration absorber shown in Fig. 1-3.
Fig. 7 is the cutaway view that increases on the motor of vibration absorber shown in Fig. 5 behind the balance weight.
Fig. 8 is the mobile views of eight sand grains particles in operating process.
Fig. 9-the 12nd, the mobile view of four sand grains particles in operating process in addition.
Figure 13 is the upward view that four liners of the vibration absorber among second embodiment of wood invention are arranged.
Figure 14 is the cutaway view that the vibration absorber shown in Fig. 5 has increased the balance of fan piece.
Figure 15 is a side view of using " the dull and stereotyped sand " of vibration absorber of the present invention.
Figure 16 is the side view that the vibration absorber shown in Fig. 1 has increased brake apparatus.
Wherein:
1 eccentric rotary oscillation class instrument
2 casings
3 handles
4 inner chambers
5 motors
6 ball bearings
7 power switches
8 annular sand paper
9 circular sand paper
10 vibration absorbers
11 motor shafts
12 motor shaft center lines
13 clutch shaft bearings
13a clutch shaft bearing central point
14 clutch shaft bearing centre bores
15 clutch shaft bearing center lines
16 first (outward) liner
The 16a inner chamber
The 16b outer surface
The orientation of 16z first liner 16
17 first support members
The 17a tapered segment
The 17b annular section
Center cavity below the 17c
The cylindric center of 17d cramping body
Center cavity above the 17e
The 17f air suction opening
18 pairs of eccentric block assemblies
18a first cam
18b second cam
The 18c centre bore
The two eccentric block assembly central points of 18d
19 second bearings
19 a, second bearing, 19 central points
The centre bore of 20 second bearings 19
The center line of 21 second bearings 19
22 second (interior) liner
The 22a outer surface
The orientation of 22z second liner 22
23 second support members (holder)
The 23a center cavity
24 little gaps
24a minimum clearance
The barycenter of 25 elements 16,17
The barycenter of 26 elements 22,23
27 straight lines perpendicular to center line 12
28 balance weights
The barycenter of 29 balance weights 28
The barycenter of 29A balance weight 28 and fan 43
30 elements 16,22,17,23, the barycenter of 13,19,18 center-of-mass systems
31 elements 16,22,17,23,13,19,18,28, the barycenter of 43 center-of-mass systems
The rotation arrow of 33 outer liners 16
The rotation arrow of 34 inner liner 22
40 ring liners, 16 orbit centres, 15 arrows
41 circular pads, 22 orbit centres, 21 arrows
42 connecting lines
43 cooling fans
44 collecting chambers
45 air and dust discharge pipe
46 first Flexible Connectors
47 second Flexible Connectors
50 first brake apparatus
51 second brake apparatus
A, b, c, d sand grains particle
E1, the e2 eccentric throw
F1, f2. power
J. eccentric throw
K, l, m. sand grains particle
Q. distance
T. circumference
F1, F2. is outer, the exterior surface area of inner liner
K1, K2. power
P. plane
A1, A2, A3, A4. liner
B1, B2, B3, B4. liner A1, A2, A3, the surface area of A4
S1, S2, S3, S4. liner A1, A2, A3, A4 center line
C1, C2, C3, C4. liner A1, A2, A3, the area of A4 center circle
R1, R2, R3, R4. liner A1, A2, A3, A4 and area C1, C2, C3, C4 track centerline
T1, T2, T3, T4. track direction of rotation arrow
D1=d2=d3=d4. track centerline R1, R2, R3, R4 is to the distance of rotation centerline 12
C1 (3), C2 (3), C3 (3), C4 (3). each center circle area when (3) in the position
O1, O2, O3, O4. liner A1, A2, A3, the orientation of A4
The specific embodiment
With reference to accompanying drawing 1, disclosed a kind of eccentric rotary oscillation class instrument 1 that combines the vibration absorber of the embodiment of the invention, as sander or polishing machine.
Eccentric rotary oscillation class instrument 1 all has the casing 2 and the inner chamber 4 of band handle 3 to adorn motor 5 basically, and for example motor has motor shaft 11 and longitudinal centre line 12, and motor shaft 11 is supported by ball bearing, needle bearing or oiliness bearing.Motor 5 can not be electronic, as also can being pneumatic.Axis 12 also can be said to be motor shaft center line or rotation.Motor 5 can be worked under any speed or even very high speed.The typical scope of design of the rotating speed of motor 5 is 2000-12000 rpm.
Power switch 7 is arranged on the handle 3 and makes the operator easy to operate, and it connects motor 5 and (does not show on the accompanying drawing) on main power source, rechargeable battery or compressed air cylinder.
Motor shaft 11 couples together by mechanical driving device and the liner 16,22 that comprises vibration absorber 10, and liner 16,22 supports smooth abrasive body 8,9, as frosted layer or sand paper.The amplitude that transmission device and vibration absorber 10 are fit to support abrasive body 8,9 and reduce vibration, and this vibration is produced by the reaction force of workpiece to instrument liner 16,22 usually, this reaction force acts on motor shaft 11, casing 2 and the operator then.
In order to reach this target, comprise that the transmission device of vibration absorber 10 makes that liner 16,22 is inequality and separated from one another.Liner 16,22 has equal quality, and preferably their work area F1, F2 also equates.The outer surface of liner 16,22 is positioned on the same plane P.
In addition, the transmission device that is driven by motor shaft 11 is configured to liner 16,22 is rotated, and can do anti-phase orbiting motion.But, thereby reduced the vibration that is delivered on the motor shaft 11 by orbiting motion power compensation inertia and frictional force.
Orbiting motion can be paid the utmost attention to.
Specifically, transmission device and vibration absorber combine a pair of pair of eccentric block assembly 18, and this pair eccentric block assembly 18 has driving liner 16,22 to be the cam 18a of orbiting motion, 18b respectively.This is further described below.
Casing 2 comprises a collecting chamber 44 that is positioned on two eccentric block assemblies 18.Collecting chamber 44 connects an air and a dust discharge pipe 45 that is positioned under the handle 3.An extraction fan (figure does not show) can be connected to the health of protecting the operator on the discharge pipe 45.
With reference to Fig. 2-6, the vibration absorber 10 of eccentric rotary oscillation class instrument 1 comprises first (outward) liner 16 of annular, and liner 16 has a middle inner chamber 16a and first an outer surface 16b who is connected annular sand paper 8.The outer surface 16b area of supposing outer liner 16 is F1.Outer liner 16 is connected on the first bell support member 17.Vibration absorber 10 equally also comprises discoid second (interior) liner 22.Inner liner 22 is placed among the inner chamber 16a of outer liner 16, and second an outer surface 22a who connects circular sand paper 9 is arranged.The outer surface 22a area of supposing inner liner 22 is F2.Area F1, F2 are preferably equal, just F1= F2.Outer surface 16b, 22a are arranged in same plane P (seeing Fig. 1 and Fig. 5).Columned second supporter 23 is positioned on the inner surface of inner liner 22, and has formed a columned cavity 23a.
As can be seen from Figures 2 and 3, the bell support member 17 of outer liner 16 has a tapered segment 17a to link to each other with planar circular 17b, the cavity 17c below having formed.Can also have one cylindric in the middle of cramping body 17d (figure does not show) connect the center cavity 17e of annular 17b above forming one.The center cavity 17e is here formed by annulus 17b.From Fig. 2, on 3 and 5, on the supporter 17, particularly on tapered segment 17a, have an air and dust SS 17f at least as can be seen.A fan (on the figure and do not show) is connected on the pipe 45, and it can take dust and chip away in frosted or polishing process.
The clutch shaft bearing 13 and second bearing 19 all are ball bearing or needle bearing.The outer surface of clutch shaft bearing 13 is installed in the last center cavity 17e of annulus part 17b.And the outer surface of second bearing 19 is installed among the inner chamber 23a of cylindric cramping body 23 of inner liner 22.The central point of clutch shaft bearing 13 is 13a, centre bore be 14 and center line be 15.The central point of second bearing 19 is 19a, centre bore be 20 and center line be 21.
Center line 15,21 is parallel with rotation centerline 12, but lays respectively at the both sides of rotation centerline 12.The central axes of center line 15 and outer liner 16 and its supporter 17, and the central axes of center line 21 and inner liner 22 and its supporter 23.Such design can make the barycenter 25 of outer lining pad 16 and its supporter 17 and the barycenter 26 of inner liner 22 and its supporter 23 be positioned at perpendicular on the straight line 27 of rotation centerline 12 (as shown in Figure 5).When outer liner 16 keeps its directed 16z (see figure 4), center line 15 will when operation, occur and center on rotation centerline 12 rotations or do orbiting motion (according to the embodiment of Figure 15).When inner liner 22 keeps its directed 22z (see figure 4), center line 21 will when operation, occur and center on rotation centerline 12 rotations or do orbiting motion, but change 180 ° (according to embodiment of Figure 15) with respect to the rotation of center line 15.
From Fig. 1-7 as can be known the primary element of vibration absorber 10 are eccentric block assemblies 18.Eccentric block assembly 18 is made up of the first cam 18a that links together and the second cam 18b.Cam 18a, the 18b shape is identical but position each other has been changed 180 ° in the vertical.In the centre of eccentric block assembly 18 through hole 18c is arranged, make it and motor shaft 11 be fastenedly connected.Thereby the center line of through hole 18c overlaps with rotation centerline 12.
As can be seen from Figure 6, cam 18a, 18b are actually cylindric, and they can be other shapes also, as ellipticity.Their center line is designated as 15 and 21 respectively.Cam 18a, 18b constitutes a single integral body, metal as by monoblock.Cam 18a, 18b also can be tightened together afterwards by two discrete components again.With respect to the eccentric distance e 1 of center line 12, e2 also just is respectively the distance between center line 15,12 and 21,12, the race way diameter that is equal to each other (e1=e2) and equals to expect separately for cam 18a, 18b.
The outer surface of first (top) cam 18a is fastening to be installed in the centre bore 14 of clutch shaft bearing 13, and in the fastening centre bore 20 that is installed in second bearing 19 of second (following) cam 18b.The rotation of motor shaft 11 passes to cam 18a, and 18b by the rotation of bearing 13 and 19, and then passes to the liner 16 and 22 that supporter 17,23 is connected separately with them again respectively.(in the embodiment of Figure 15, liner 16,22 remains at 16z in whole rotary course, the 22z direction) thereby, liner 16,22 formed eccentric orbits have been changed 180 ° each other.
With reference to Fig. 4 and Fig. 5 as can be known, the external diameter of inner circular liner 22 is slightly less than the internal diameter of outside ring liner 16, makes can keep a predetermined minimum clearance 24a 16,22 of liners in whole rotary manipulation process.Can be in operating process in the gap 24 of 16,22 of liners as siphoning away the chip on the workpiece and the passage of dust.This swabbing action is produced together by fan (on the figure and do not show) and discharge pipe 45 associatings.
In operating process, liner 16,22 produces power K1 respectively, the K2 (see figure 4).Power K1, the action direction of K2 opposite (because 180 ° anti-phase cause is arranged) is eliminated vibration, has then passed to the operator otherwise the major part of this vibration can be delivered to the casing 2 of instrument 1.Even the operator load of instrument 1 has been increased, this vibration also can be eliminated.
With reference to Fig. 7, power f1 in the process of operation tool 1, f2 produces a little moment of torsion at point 30 places, is by liner 22,16 and put 30, supporter 17,23, the barycenter of the system that bearing 13,19 and cam pack 18 constitute.Power f1, f2 is produced by centrifugal motion, and can cause vibration.In order to eliminate this moment of torsion, can on motor shaft 11, increase a balance weight 28.Balance weight 28 can securely be directly connected on motor shaft 11 or the assembly 18, perhaps is connected to by on the cooling fan 43 of motor 4 driving cooling motors (as shown in figure 14).The barycenter 29 of balance weight 28 is not on motor rotation centerline 12.In Fig. 7, indicated its eccentric throw j.Balance weight 28 can be Any shape basically.Here usefulness is cylindric.Yet, we it should be noted that outer liner 16 adds that the quality of its supporter 17 equals the quality that inner liner 22 and its supporter 23 add balance weight 28, in order to reach the purpose of balance, being not only quality must be like this, and they also will be like this to the distance of point 31.Make whole barycenter still on point 31.
With reference to Fig. 8, externally liner 16 and inner liner 22 are described further.This will illustrate the effect of vibration absorber 10.The outer surface 16b of liner 16,22,22a is positioned on the same plane P.And supposing their area F1, F2 equates.Perhaps this requirement is not satisfied in some instances.In operating process, the center line 15 of the outer liner 16 of annular has been drawn a roundlet around the rotation centerline 12 of motor shaft 11, and has the center line 21 same rotation centerlines 12 that center on of the circular inner liner pad 22 of 180 ° of phase differences to draw a roundlet with center line 15.These two roundlets are used arrow 40,41 indications respectively.
A connecting line 42 is center line 15,12, and 21 couple together.The distance that distance that center line is 12,15 and center line are 12,21 equates.This is to make first-selection simple in structure design, but some the time with situation under can and the condition of selection here deviate from mutually.
Suppose that arrow 16z is fixed on the outer surface 16b of outer liner 16, it has indicated predetermined direction or the location of outer liner 16 with respect to instrument 1, can be front point backward from instrument 1 such as it.Suppose that arrow 22z is fixed on the outer surface 22a of inner liner 22.It indicated equally inner liner 22 with respect to instrument 1 pre-determine direction or location, can be front point backward from instrument 1 equally such as it.In the embodiment of Figure 15, liner 16,22 remains at predetermined direction 16z in operating process, and 22z is crucial.In other words, (indicated five with (1) to (5) in Fig. 8) in all operating positions, arrow 16z, 22z are the straight lines that is parallel to predetermined vertical electric rotating machine center line 12.
Suppose eight grit particle a, b ... the position of rotation that h indicates with (1) at the outward flange of liner 16,22.Suppose the particle a on the liner 16, b, c, d separate with 90 ° of angles each other, and the particle e on the same liner 22, f, g, h separate with 90 ° of angles each other.Particle a-h moves on the roundlet of same diameter, passes through position (1)-(5) continuously, thereby the effect of polishing is arranged on processed workpiece.
In Fig. 9-12, we can see that liner 16,22 is in four coherent positions (1) respectively, (2), three particle k when (3) and (4), l, the motion of m.In this example, particle k, l, m are positioned at the inside of liner 22 and 16.Moreover particle k, l, m also are the circular motion along same diameter.
With reference to Fig. 8 to 12, it must be emphasized that, except being arranged, the liner 16 and 22 that also has the internal friction power by bearing 13 and 19 to cause respectively along the orbiting motion of circle t rotates.The rotating speed of this rotation depends on the load that sand paper 8 and 9 is subjected to respectively.In Fig. 8 to 12, indicate this rotation with arrow 33 and 34 respectively.Ring liner 16 rotates around its center line 15 all the time, and circular pads 22 is rotated around its center line 21 all the time.This rotation is hereinafter referred to as " liner rotation ".They have caused the corase grind to workpiece, and the track rotation has caused the correct grinding to workpiece.
Is two ball bearings 13 and 19 at liner 16,22 with unique connection between casing with reference to Fig. 1-7 (comparing with Figure 14).Double cam assembly 18 is fastenedly connected on the motor shaft 11, makes cam 18a, and the rotating speed of 18b is identical with the rotating speed of motor shaft 11.Cam 18a, two liners 16,22 of 18b driving as discussed above.
Less relatively frictional force just drives the power that liner 16,22 rotates around their center lines 15,21 separately respectively on the steel ball of ball bearing 13,19.If instrument 1 is worked under zero load, as the operator it is held in the air, because in this state, sand paper 8,9 and workpiece between do not have frictional force, liner 16,22 with motor shaft 11 same directions (seeing arrow 33 and 34) beginning the rotation, and liner 16,22 quickens finally to reach the rotating speed the same with motor shaft 11 until them.
Yet in case to instrument 1 imposed load, just work as sand paper 8,9 and surface of the work and contact, the rotating speed of liner 16,22 will sizablely reduce.Liner rotation (seeing arrow 33,34) almost stops, and can only keep a kind of very low rotating speed to roughly grind.And the rotation of this track can continue to keep, and what this moment, their were primarily carried out is the work of polishing.
From above explanation, the rotating speed and the corase grind of liner rotation depend on the magnitude of load that applies as can be known for we.In contrast, the rotating speed of track rotation (can be used for eliminating vibration) depends on rotating speed of motor, and correct grinding or dull and stereotyped sand do not depend on the magnitude of load that applies.
In the course of the work, the frictional force of the frictional force of liner 16 and load (as desktop) and liner 22 and load (as desktop) not always, caused the liner rotation of liner 16 and liner 22 also different.But this performance to vibration damping has no impact, because the liner of low speed rotation not causing vibration.
The eccentric rotary oscillation class instrument of this mode of operation can be called as " circle sand machine ", " sander ".
At the passed the imperial examinations at the provincial level embodiment of four liners of Figure 13.It is the same that its operation principle and Fig. 1-12 are disclosed.
Four liner A1, A2, A3, A4 do the square arrangement of symmetry.They are arranged in the center line 12 same plane on every side of motor shaft 11.All liner A1-A4 shapes are identical, and what use in the present embodiment is rectangle, particularly square.All liners all are flat, and have identical surface area B1-B4 to connect the dry sanding paper or the polishing paper of same size.Suppose sand grains particle a, b, c, d is at the exterior angle of liner.Suppose that in operating process sand grains particle a-d has coherent position (1), (2), (3), (4) or the like have only indicated position (1) and (3) on diagram.Position (3) has been changed 45 ° with respect to position (1) on exterior angle arrow direction indication.Liner A1-A4 and center are to represent with solid line at the border circular areas C1-C4 of a S1-S4 on position (1), are to dot on position (3).These central points comprise that the center line of liner A1-A4 all indicates with S1-S4.
The center line S1-S4 of liner A1-A4 and their central area C1-C4 does orbital motion around four center line R1-R4, continuously by the position (1) on less circle (on the figure and do not show), (2), (3), (4) or the like.Track centerline R1-R4 is equal with the distance of the rotation centerline 12 that is positioned at liner arrangement center, i.e. d1=d2=d3=d4.
T1, T2, T3, what T4 indicated is the direction of motion of orbital motion.Among all liner A1-A4, the direction of every adjacent two liner orbital motions is opposite, liner A1 thus, and A2, A3, A4 predetermined direction O1 separately, O2, O3, O4 remains unchanged.Therefore, eliminated vibration.
The function that cam pack (figure does not show) and gear assembly (figure does not show) are carried out.Cam pack is similar to Fig. 6's, can comprise that two (preferably cylinder or column) cams connect liner A1, A3 and A2, and A4, and also these two cams all are connected on the motor shaft 11.By such cam pack and gear assembly, the rotation of motor center line 12 is delivered to four center line S1, S2, and S3, S4 rotates along arrow T1-T4 indicated direction thereby driven liner A1-A4.In this design, suppose the position that when the round C1-C4 shown in each liner A1-A4 solid line has indicated in the position (1), connects cylindric cam, and when the round C1-C4 shown in each liner A1-A4 dotted line has indicated in the position (3), connect the position of cylindric cam.
Equally in this embodiment, also can reach the purpose that reduces vibration.
Except orbital motion, thereby total has been carried out " the liner rotation " of corase grind around rotation centerline 12 rotations.
This embodiment can be designed to dull and stereotyped sand equally.
With reference to Figure 14, the cooling fan 43 of a cooling motor 4 is installed on the motor shaft 11.A balance weight 28 is positioned on the following outer surface of cooling fan 43.The barycenter 29A of cooling fan 43 and balance weight 28 is not on rotation centerline 12.Compensated imbalance in this way.
Figure 15 has disclosed the embodiment of " dull and stereotyped sand ".The embodiment of it and Fig. 1 is basic identical, and different is that it has comprised at least one first Flexible Connector 46 and at least one second Flexible Connector 47.These two connectors 46,47 can be elongated and all be to be made by elastomeric material, as rubber.First connector 46 is mounted on outer liner 16 of annular and the casing 2, and second connector 47 is mounted on circular inner liner pad 22 and the supporter 17, just between liner 22 and the casing 2.Two connectors 46,47 make liner 16,22 not rotate around their center lines 15 and 21 separately respectively.Since can not carry out this rotation, sand paper 8 and 9 can only move along roundlet t as Fig. 8 to 12 is said, shows as orbital motion.In other words be exactly, nonrigid connector 46,47 has been prevented front said " liner rotation ", but allows " track rotation ".
In Figure 16, illustrate two and can be used on brake apparatus 50,51 in the round sand machine shown in Figure 1, reduced the rotating speed of liner 16 and 22, particularly in instrument 1 zero load.Rotating speed can be because the effect that brake apparatus 50,51 has been simulated load by lowering.The brake apparatus of here using 50,51 can be the rubber ring of various different-diameters.