JP3185001B2 - Vibration method and apparatus for plate compactor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for oscillating a plate compactor, and more particularly to a method and an apparatus for oscillating a plate compactor having good running performance and extruding asphalt mixture. It concerns the device.

[0002]

2. Description of the Related Art FIG. 6 is a side sectional view of a conventional two-axis vibration type plate compactor, in which i is a plate and j is a plate.
Is fixedly installed on this plate i to provide the first eccentric shaft a
And a vibrator, k, which vibrates the plate by the rotation of the second eccentric shaft b, is mounted and fixed on a base f fixedly installed on the plate i via vibration isolating members g, g '. Drive source, n is a centrifugal clutch mounted on the output shaft of the drive source k, o is a belt transmission mechanism for transmitting the rotational power of the drive source k to the second eccentric shaft a, and q is mounted on the base f. Steering handle. The first eccentric shaft a and the second eccentric shaft b to which the rotational power of the drive source k is transmitted are supported in a parallel manner, and are rotatable in opposite directions via a gear mechanism (not shown). Are linked.

[0003]

The above-described conventional two-axis vibration type plate compactor has a higher traveling speed than a one-axis type plate compactor, but when the soft ground is compacted, the working speed becomes extremely high. descend. this is,
For the following reasons:

As shown in FIG. 6, a conventional two-axis vibrating plate compactor vibrates in such a manner that eccentric weights having the same rotational moment are arranged on the same horizontal plane, obliquely upward in the traveling direction, and opposite to the traveling direction. in the oblique lower, so that the phase is aligned at an angle phi ₁ formed with the vertical direction, at the same rotational speed, a method of rotating in opposite rotation to each other, the relationship of the excitation force F corresponding to both eccentric mass of phase , As shown in FIG. That is, each stage of the vector of the vibrating force starting from the center of gravity acting on the center of gravity of the unsprung weight corresponding to each stage (1 to 8) of each phase of both eccentric masses in FIG. a)
(1-8). Therefore, due to the two eccentric masses, the vibrating force F applied to the center of gravity of the weight of the plate compactor (hereinafter, referred to as unsprung in this specification) located below the vibration isolating member is represented by (a) in FIG. as shown in), the angle phi formed between the vertical direction in phi _1, periodically changes along a straight line. Here, the applied with vibratory force F angle phi = phi ₁ from the vertical direction, when the weight of the plate compactor to is W, the relationship of the force in Fig. 6 is made as shown in FIG. 8,
The normal reaction N from the ground to the plate is N = W + F cos φ ₁ , and the maximum frictional force F _m is F _m = μN = μ (W + F cos φ ₁ ). The condition that the plate compactor does not slide on the ground is: F sinφ ₁ ≦ F _m = μ (W + F cosφ ₁ ) The vibrating force of the plate compactor is usually about 20 times its own weight. ₁ ≦ F _m = μF cos φ ₁ That is, if the static friction angle is φ _m and tan φ ₁ ≦ μ = tan φ _m ∴φ ₁ ≦ φ _m , the plate compactor will not slip.

[0005] However, in the case of soft ground, the static friction coefficient μ of the ground is small.・ Viscous damping coefficient c of the ground is large. There is such a characteristic.

Since the coefficient of static friction μ of the ground is small, φ _m is also small, and the possibility of slipping on a soft ground is high because the ground does not slip on ordinary ground. In the conventional two-axis vibrating plate compactor shown in FIG. 6, since the vector angle φ applied obliquely below the vibrating force F is always constant, if the vibrating force is applied obliquely downward when φ _m is smaller than φ, It becomes almost slippery, resulting in extremely slow work speed.

Further, since the soft ground has a large viscous damping coefficient c, the phase of the normal force N from the ground to the plate lags behind the vertical component of the vibrating force F. For this reason, when the vibration which moves the plate compactor in the direction opposite to the forward direction becomes near the maximum value, the reaction force of the plate compactor from the ground becomes
For still smaller value, by not work enough frictional force F _m, a sufficient running speed does not appear to slip.
For example, in (a) of FIG. 7, the excitation force F is "5" in the figure.
When, unless introduce a phase delay in the normal force N from the ground, the maximum value of the excitation force F as F _max, although the _{N = W + F max · cosφ} 1, in φ ₁ = 45 °, 45 ° of when produce phase _{delay, N = W + F max ·} cosφ 1/2 1/2 , and the compared to the case where there is no phase delay, the value of N is reduced. Thus, although the value of the vibrating force F is large, the maximum friction coefficient _Fm is a small value, so that it is easy to slip.

On the other hand, the plate compactor is used for compacting a narrow place, a wall, a manhole, a slope, etc., which cannot be paved with a large compacting machine, and also used for a road repair type. However, at that time, the asphalt mixture is often compacted by hand. In such a case, when the work is performed using a conventional two-axis vibration type plate compactor as shown in FIG. 6, the unsprung weight is inclined when the plate lands on the ground as shown in FIG. In some cases, the asphalt mixture on the front side of the front portion rises, causing a so-called extrusion phenomenon, which may damage the compacted surface. That is, when the asphalt mixture As by hand is compacted by using the machine P like a compacted road surface As ', the machine P tilts as shown by P', and the asphalt mixture in front of the plate front portion is inclined. The raised portion U is formed in the material. This is for the following reasons.

When the plate is lifted from the ground due to vibration, the weight of the plate compactor located above the vibration isolating member, that is, the weight on the spring, is not affected, but the influence is regarded as small. And, the unsprung is in a state where it can freely rotate around the center of gravity of the unsprung weight,
The moment M _t generated by the exciter device, unsprung starts the rotational movement, the kinetic energy due to the rotation is stored. It is presumed that when a large amount of this kinetic energy is accumulated and the plate lands and converts the energy into work at once, a phenomenon of "extruding the asphalt mixture" occurs.

FIG. 10 is an explanatory diagram of a vibration system for a conventional two-axis vibration plate compactor, in which an eccentric mass portion is symbolized. A first eccentric shaft a and a second eccentric shaft b are arranged at a position substantially equidistant from a point c above the center of gravity G of the unsprung weight with an inter-axis distance L in a parallel manner. m and the distance r from the eccentric axis are the same, and the angular velocity of rotation in the opposite direction is ω. During the operation of the plate compactor, the angular velocity ω is usually a constant value. A straight line ED that passes through the center of gravity G below the vibration isolating member and forms an angle φ ₁ at which the phases of the eccentric weights of the first eccentric axis a and the second eccentric axis b coincide with each other, 2
The line segment ab connecting the two eccentric axes a and b is divided into two line segments, and the line segment length on the first eccentric axis a side is defined as L '. Around the unsprung weight of the center of gravity G when the first eccentric axis a and the second phase of the eccentric weight of the eccentric shaft b is rotated by an angle θ from the matched state, calculates the moment M _t applied from the eccentric shaft I do. M _t = −mrω ² cos θ × L ′ cos φ ₁ + mrω ² cos θ ×
(L−L ′) cos φ ₁ + mrω ² sin θ × (L ′ sin φ ₁
+ H / cosφ ₁ ) + mrω ² sin θ × ｛(LL ') sin
_{φ 1 -h / cosφ 1) =} mrω 2 (L-2L ') cosφ 1 cosθ + mrω 2 L sin
phi ₁ sin [theta moment M _t is divided into the second term comprising a first term and a variable sin [theta and other constants including variable cosθ and other constants.

FIGS. 11A and 11B show the angle θ and FIG.
The values of cos θ and sin θ corresponding to the phases of each phase shown in FIG. Strictly speaking, it varies slightly depending on the conditions of the ground, the conditions on the spring, and the like, but the outline of the numeral 7 in FIG.
It is assumed that the plate is in the air during the stages → 8 → 1 → 2 → 3. Looking at (a) and (b) of FIG. 11 focusing on the period, cos θ is all on the plus side, and sin θ is initially the maximum negative value (stage 7), but is the intermediate stage (stage 1). In the final stage (stage 3), the value becomes a positive maximum value, and the point is symmetric with respect to the origin.
That is, the formula of the moment M _t is, 7 → 8 → 1 → 2
→ During the third stage, the first term is all positive and contributes to the accumulation of kinetic energy related to rotation, while the second term is that the kinetic energy due to rotation accumulated in the first half is canceled in the second half Thus, it can be seen that it hardly contributes to the accumulation of kinetic energy related to rotation. Therefore, as in (a) of FIG. 7, two equal eccentric mass, if it is positioned so as to be horizontal in a substantially central position in the longitudinal direction of the plate compactor, the first term in the formula of moment M _t Constant term mrω ² (L-2L ')
While the plate is away from the ground, a large amount of kinetic energy due to the rotation of the unsprung weight of the plate around the center of gravity is accumulated, and when the plate lands, the energy is converted into work at once and the asphalt mixture is removed. It is assumed that a pushing phenomenon occurs.

[0012] The present invention solves the above-mentioned problems of the prior art. Even when compacting a soft ground, the traveling speed is not extremely reduced. It is an object of the present invention to provide a plate compactor vibrating method and apparatus capable of increasing the speed and preventing the occurrence of an asphalt mixture extrusion phenomenon during compaction.

[0013]

As a means for achieving the above object, the present invention has a vibrating device for applying vibration to a plate by rotating an eccentric shaft. When compacting the ground while moving it, the exciter uses the exciter to determine the locus of the end point of the force vector starting from the center of gravity acting on the center of gravity of the weight below the anti-vibration member. Along the elliptical shape that is inclined so as to be obliquely upward from the opposite diagonal downward direction, and above the elliptical shape, in the same direction as the traveling direction of the plate compactor, below the elliptical shape In the above, a plate compactor vibrating method characterized in that the plate compactor is circulated in a rotational direction opposite to the traveling direction. Further, the vibration isolating member is positioned on the lower side to support a drive eccentric shaft to which the rotational power of the drive source is transmitted, and one or more driven eccentric shafts.
One is connected to the drive eccentric shaft via a transmission mechanism so as to be rotatable in the opposite direction to each other, and by rotating each of the eccentric shafts, a vibration generator of a plate compactor that applies vibration to the plate prevents vibration from being generated by a vibration generator. The trajectory of the end point of the force vector starting from the center of gravity acting on the center of gravity of the weight below the vibration member is inclined such that the major axis is obliquely downward from the direction opposite to the traveling direction of the plate compactor and obliquely upward in the traveling direction. Circulate in an elliptical shape, and rotate the direction of circulation,
The vibrating system of the plate compactor is characterized in that it has a vibration system that is in the same direction as the traveling direction of the plate compactor on the upper side of the elliptical shape and is opposite to the traveling direction on the lower side of the elliptical shape. At the same time, the eccentric moments of the drive eccentric shaft and the driven eccentric shaft rotating in the opposite direction are made different, and the rotational direction of the eccentric shaft with the larger eccentric moment is set above the eccentric shaft. In the same direction as the traveling direction of the plate compactor, it is configured so as to be opposite to the traveling direction of the plate compactor below the eccentric shaft, and further, the center of gravity of the lower weight is separated by separating the vibration isolating member. As described above, a line segment connecting the two eccentric shafts with a drive eccentric shaft and a driven eccentric shaft that rotates in the opposite direction with respect to the two eccentric shafts by a straight line that forms an angle at which the phases of the eccentric weights coincide with each other. When divided into One line segments, the percentage of the eccentric moment of the two eccentric shafts, with each other, and configured as a substantially equal ratio to the segment length farther.

[0014]

According to the above-described means, even when the coefficient of static friction is small and the static friction angle (φ _m ) is small because the ground is soft, the vibrating force F acting on the center of gravity G of the unsprung weight circulates in an elliptical shape. Therefore, at least the angle (φ) between the vibrating force F and the vertical direction is always equal to or less than the static friction angle (φ _m ) within a certain range below the elliptical shape (φ ≦ φ _m ), And the ground is surely gripped in that range. The magnitude of the normal drag N from the ground to the plate is
While the plate is in contact with the ground, the value of the weight W of the plate compactor is considered to be sufficiently small compared to the value of F,
If the value of W is neglected, the value changes substantially in accordance with the increase or decrease of the vertical component of the force F. However, since the soft ground generally has a large viscous damping coefficient c, the phase of the normal force N lags behind the phase of the vertical component of the vibrating force F. However, even in the soft ground, the force F circulates in an elliptical shape, so that even if the phase of the normal force N is delayed, the normal force N becomes rather large in accordance with the timing at which the plate kicks the ground backward by vibration. It becomes a tendency. Therefore, it becomes difficult to slip.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side sectional view of a two-axis vibration type plate compactor embodying the present invention. A base m is fixedly mounted on the upper part of the plate i via vibration isolating members g and g ', and the rotational power of a driving source k mounted and fixed on the base f is applied to a second eccentric shaft by a belt transmission mechanism o. (Drive eccentric shaft). The first eccentric shaft (driven eccentric shaft) A is
The second eccentric shaft B is rotatably connected to the second eccentric shaft B in opposite directions via a gear mechanism (not shown). The vibrator j is constituted by the rotation of the drive eccentric shaft B and the driven eccentric shaft A, and the plate i
Give vibration. At this time, the drive eccentric shaft B and the driven eccentric shaft A rotating in the opposite direction to the drive eccentric shaft B have different eccentric moments, and are formed obliquely upward in the traveling direction and opposite to the traveling direction. in obliquely downward, so that the phase is aligned at an angle phi ₁ formed with the vertical direction, at the same rotational speed,
Rotate them in opposite directions and rotate the eccentric shaft with the larger eccentric moment in the same direction as the plate compactor on the eccentric shaft and in the opposite direction from the plate compactor on the eccentric shaft. It is set to be.

FIG. 2 shows the relationship between the oscillating forces corresponding to the phases of the two eccentric masses. That is, the stage of the vector of the vibrating force starting from the center of gravity acting on the center of gravity of the unsprung weight corresponding to the stage (1 to 8) of each phase of both eccentric masses in FIG. )) (1-8). Therefore, the trajectory of the end point of the vector circulates in an elliptical shape in which the major axis is inclined from the diagonally lower side opposite to the traveling direction of the plate compactor to the obliquely upward direction in the traveling direction, and the rotating direction of the circulation is The upper side of the elliptical shape has the same direction as the traveling direction of the plate compactor, and the lower side of the elliptical shape has the opposite direction to the traveling direction. In this case, the ratio of the magnitude of the eccentric moment of the two eccentric shafts is as follows. A straight line that passes through the center of gravity G of the unsprung weight and forms an angle at which the phases of the eccentric weights of the two eccentric shafts, the eccentric shaft A and the eccentric shaft B rotating in the opposite direction, coincide with each other, When a line segment connecting the eccentric shafts is divided into two line segments, the ratio of the eccentric moments of the two eccentric shafts is set to a ratio substantially equal to the length of a line segment farther from each other.

FIG. 1 shows an embodiment in which the eccentric axes A and B are on the same horizontal plane, and is an example in which the eccentric axis B in FIG. 3 coincides with the position of B '. FIGS. 3 and 4 show an embodiment in which the eccentric axes A and B are symbolized to represent the eccentric mass portion, regardless of whether or not they are on the same horizontal plane. A straight line DE which forms an angle in the direction where the phases of the eccentric weights of B coincide with each other and passes through the center of gravity G of the unsprung weight
Is closer to A than B of the two eccentric axes, FIG.
FIG. 4 shows the case where the straight line DE is closer to B than A of the two eccentric axes.

As described above, in the compaction work of asphalt mixture by the plate compactor, a large amount of kinetic energy is accumulated due to the rotational motion of the unsprung weight around the center of gravity when the plate lands after leaving the ground due to vibration. , The kinetic energy at once, at the time of landing,
Converted to the task of "extruding asphalt mix", which has a negative effect on the compacted surface. First, the embodiment shown in FIG. 3 is a case where the unsprung weight is set in a hatched portion in FIG. 3, and this case will be described. Also in FIG. 3, similarly to FIG. 1, the eccentric shaft A and the eccentric shaft B transmit power through gears and the like, and rotate at an angular velocity ω in directions opposite to each other and in the direction shown in FIG. 3. . The eccentric axis A has an eccentric mass of magnitude M at a distance R from the eccentric center A, and the eccentric axis B has an eccentric mass of magnitude m at a distance r from the eccentric center B. In addition, a relationship of MR> mr is established. Further, the two eccentric shafts are formed by a straight line passing through the center of gravity of the unsprung weight and forming an angle at which the phases of the two eccentric shafts of the drive eccentric shaft and the driven eccentric shaft rotating in the opposite direction coincide with each other. When the connected line segment is divided into two line segments, the ratio of the eccentric moments of the two eccentric shafts is substantially equal to the length of the line segment farther from each other. When the symbol is used, the expression is replaced by the following expression: MR / mr ≒ (L−L ′) / L ′. Next, the embodiment of FIG. 4 is a case where the unsprung weight is set in the shaded area in the figure, and this case will be described below. As for FIG.
The shaft A and the eccentric shaft B transmit power via gears or the like, and rotate at an angular velocity ω in directions opposite to each other and in the direction shown in FIG. The eccentric axis A has an eccentric mass of magnitude M at a distance R from the eccentric center A, and the eccentric axis B has an eccentric mass of magnitude m at a distance r from the eccentric center B. In addition, the relationship of MR <mr holds. Further, the two eccentric shafts are formed by a straight line passing through the center of gravity of the unsprung weight and forming an angle at which the phases of the two eccentric shafts of the drive eccentric shaft and the driven eccentric shaft rotating in the opposite direction coincide with each other. When the connected line segment is divided into two line segments, the ratio of the eccentric moments of the two eccentric shafts is substantially equal to the length of the line segment farther from each other. The use of the symbol replaces the expression MR / mr ≒ (L-L ') / L'.

[0019] and the excitation force F acting on the center of gravity G of the weight of unsprung in FIG 3, calculates the moment M _t around it.

The vibrating force F applied to the center of gravity G of the unsprung weight is divided into an X coordinate component F _X and a Y coordinate component F _Y in FIG. F _X = −MRω ² sinθ + mrω ² sinθ = − (MR−
mr) ω ² sin θ F _Y = MRω ² cos θ + mrω ² cos θ = (MR + m
from r) ω ² cosθ both ^{_{equations, F X 2 / {(MR}} -mr) ω 2} 2 + F Y 2 / {(MR
+ Mr) ω ² ｝ ² = 1 Equation 1 As a result, the excitation force F applied to the center of gravity G of the unsprung weight
Is a vector of force starting from the center of gravity G, and the trajectory of the end point follows an elliptical shape that is inclined such that the major axis is obliquely downward from the direction opposite to the traveling direction of the plate compactor and obliquely upward in the traveling direction. The vibration shown in FIG. 2A circulates in a rotational direction in which the upper side of the elliptical shape is in the same direction as the traveling direction of the plate compactor, and the lower side of the elliptical shape is in a direction opposite to the traveling direction. You can see that it takes a system.

The coefficient of friction of soft ground is generally
Is smaller because the static friction angle phi _m is small, as described above, the force F is, therefore circulates in an elliptical shape, at least,
Angle the force F makes with vertical phi always within a certain range on the underside of the elliptical shape in the (a) 2, next phi ≦ phi _m,
In that range, the ground is surely gripped. Therefore,
The plate does not always slip when kicking the ground, and the running speed does not drop extremely.

The magnitude of the normal force N from the ground to the plate is determined by comparing the value of the weight W of the plate compactor with the value of F while the plate is in contact with the ground, assuming that the weight is sufficiently small. If the value is ignored, the value changes substantially according to the increase or decrease of the vertical component of the force F. However, since the soft ground generally has a large viscous damping coefficient c, the phase of the normal force N lags behind the phase of the vertical component of the vibrating force F. But force F
Circulates in an elliptical shape as shown in FIG. 2 (a). For example, in FIG. 2 (a), when the value of N when the force F is "5" and the value of N is "4", The maximum frictional force becomes large due to the value of the vertical component, and slip becomes difficult. When the phase lag is as shown in FIG. 2A, when the force F is "6 '" (the force F
At the time of the maximum value of the horizontal component), if the shape of the circulating ellipse is such that the vertical component of the force F when the value of N is "4 '", then at the time of the maximum propulsive force, The frictional force is exhibited, making it ideal. From this, it is understood that excellent running performance can be obtained by applying the vibration generating method and the device thereof according to the present invention.

Next, in the compaction of the asphalt mixture by plate compactor, calculated for the moment M _t according to the extrusion of the mixture member. M _t = −MRω ² cos θ · L ′ cos φ ₁ + mrω ² cos θ · (L−L ′) cos φ ₁ + MRω ² sin θ · (L ′ sin φ ₁ + h / cos φ ₁ ) −mrω ² sin θ · p = ω ² cos φ ₁ · ｛−MRL ′ + mr (L−L ′)｝ cos θ + ω ² ｛MR (L ′ sin φ ₁ + h / cos φ ₁ ) −mrp｝ sin θ Equation 2 The first term of this equation is MR / mr ≒ (L− L ′) / L ′... Approximately 0 according to the condition satisfying Expression 3. Thus, the phenomenon of extruding the mixture by the plate that roughens the compacted surface can be prevented. The reason is described below.

Strictly speaking, although it varies slightly depending on the condition of the ground, the condition on the spring, and the like, in the case of FIG. 4 as well, each stage of the force F is roughly represented by the numeral 7 → 8 → 1 in FIG. → 2 → 3
It is assumed that the plate is in the air during this stage. Looking at (a) and (b) of FIG. 11 focusing on the period, cos θ is all on the plus side, and sin θ is initially the maximum negative value (stage 7), but is the intermediate stage (stage 1). In the final stage (stage 3), the value becomes a positive maximum value, and the point is symmetric with respect to the origin. That is, the formula of the moment M _t, during the the 7 → 8 → 1 → 2 → 3 stages, and all the first term positive, contributes to the accumulation of kinetic energy relating to rotation, the second term, the first half Since the kinetic energy due to the rotation accumulated in the stage is canceled in the latter stage, it is understood that it hardly contributes to the accumulation of the kinetic energy related to the rotation. In addition, the first term of Expression 2 is substantially 0 in the relationship of Expression 3, and almost no kinetic energy is accumulated due to rotation. As for the second term of Expression 2, from the relationship of Expression 3, p = {(L−L ′) / L ′} (L ′ sin φ ₁ + h / cos φ ₁ ). And M _t is always 0,
Although ideal, the second term in Equation 2 is the term for sin θ,
As described in detail in the above-mentioned subject, the plate hardly contributes to the accumulation of kinetic energy due to the rotational movement around the unsprung center of gravity at the time of landing after the plate is separated from the ground.
Therefore, it does not significantly affect sudden large work (collision) caused by the tip of the plate at the time of landing. Therefore,
Equation 4 does not hold, but as long as Equation 3 holds, the extrusion of the asphalt mixture does not occur. For example,
If Equation 3 is satisfied, FIG.
There is practically no problem even if the position of B is set to the position of B '.

On the other hand, as shown in FIG. 4, when the center of gravity G of the unsprung weight is set so as to fall within the hatched area in the figure, the eccentric moment of each eccentric shaft is set to MR < 3, each eccentric shaft is rotated at an angular velocity ω in a direction opposite to that in FIG. 3. Accordingly, the equation 1 is similarly established, and the force F applied to the position of the center of gravity of the unsprung weight circulates in an elliptical shape, and also acts on the center of gravity G, and is the locus of the end point of the force vector starting from the center of gravity G. However, the major axis is along an elliptical shape that is inclined so as to be obliquely upward in the traveling direction from a diagonally lower direction opposite to the traveling direction of the plate compactor, and on the upper side of the elliptical shape, with the traveling direction of the plate compactor. It can be seen that, in the same direction, the vibration system shown in FIG. Therefore, as in the case of FIG. 3, excellent running performance is obtained. Equation 2 also holds true as in the case of FIG. 3, and it is best if equation 4 holds. However, even if this does not hold, as long as the ratio of the eccentric moment of the two eccentric shafts is set as in equation 3, At the time of landing after the plate is separated from the ground, kinetic energy due to rotational movement around the center of gravity is not accumulated, and a phenomenon that adversely affects the compacted road surface, such as an asphalt mixture extrusion phenomenon, does not occur.

The trajectory of the end point of the vector of the vibrating force F based on the center of gravity of the unsprung weight does not need to be an exact ellipse, but may be any elliptical shape that approximates the ellipse. Further, in the present embodiment, the explanation has been made only for the two-axis vibration type plate compactor.
Even in the case of a shaft and other multi-shafts, it is effective within a range not departing from the gist of the present invention, and the same effects can be obtained by providing the above-described requirements.

[0027]

As described above, according to the plate compactor vibrating method and apparatus according to the present invention,
Even when the soft ground is compacted, the force F acting on the center of gravity G of the unsprung weight circulates in an elliptical shape, so that at least the angle (φ) that the force F makes with the vertical direction is constant at a certain point on the lower side of the elliptical shape. always in the range, comparable to the static friction angle phi _m or less (φ ≦ φ _m) next to reliably grip the ground in that range. Therefore, the traveling speed does not drop extremely. Normal drag N from ground to plate
When the plate is in contact with the ground, the value of the weight W of the plate compactor is considered to be sufficiently small compared to the value of F, and if the value of W is ignored, the vertical component of the force F is almost It changes with the value according to the increase and decrease of. However, since the soft ground generally has a large viscous damping coefficient c, the vertical drag N
Is behind the phase of the vertical component of the excitation force F. However, since the force F circulates in an elliptical shape, the maximum frictional force becomes large and slipping is difficult. Therefore, by applying the vibration generating method and the device according to the present invention, excellent running performance can be obtained. In addition, when compacting the asphalt mixture, the kinetic energy due to the rotational movement around the center of gravity G of the unsprung weight is not accumulated at the time of landing after the plate is separated from the ground. There is an effect that can be prevented.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a two-axis vibration plate compactor embodying the present invention.

FIGS. 2 (a) and 2 (b) are analysis diagrams of a force applied by an eccentric shaft to a center of gravity of a weight below a vibration isolating member in a two-axis vibration type plate compactor embodying the present invention. (A) shows the vector of the vibrating force corresponding to each phase of the mass (b).

FIG. 3 is an explanatory view symbolizing an eccentric mass portion of a vibration type in a two-axis vibration type plate compactor embodying the present invention.

FIG. 4 is an explanatory view symbolizing an eccentric mass portion of a vibration type in a two-axis vibration type plate compactor embodying the present invention.

FIG. 5 is an explanatory diagram of a vibration method in a two-axis vibration plate compactor embodying the present invention.

FIG. 6 is a side sectional view of a conventional two-axis vibration type plate compactor.

FIGS. 7 (a) and 7 (b) are analysis diagrams of the vibrating force applied by the eccentric shaft to the center of gravity of the lower side than the vibration isolating member in the conventional two-axis vibration type plate compactor. of
The vector of the excitation force corresponding to each phase in (b) is
Shown in

FIG. 8 is an explanatory diagram showing a relationship between a normal force and a maximum friction force.

FIG. 9 is a state diagram for explaining a phenomenon of pushing out an asphalt mixture by a conventional plate compactor.

FIG. 10 is an explanatory diagram of a vibration method in a conventional two-axis vibration plate compactor.

11 (a) and (b) respectively show cos θ and sin θ
It is a diagram illustrating a function value corresponding to the value. However, ()
The numbers in parentheses are the numbers of each phase stage of the eccentric mass in FIG. 1 (b) and FIG. 7 (b).

[Explanation of symbols]

 A first eccentric shaft B second eccentric shaft G center of gravity lower than the vibration-proofing member i plate j exciter k drive source g, g 'vibration-proofing member f base n centrifugal clutch o belt transmission mechanism

Claims (4)

(57) [Claims] 1. A vibration generating device for applying vibration to a plate by rotating an eccentric shaft. When compacting the ground while moving a plate compactor by the vibration, a vibration isolator is used by a vibration generator. The locus of the end point of the force vector starting from the center of gravity acting on the center of gravity of the weight below the member,
The major axis extends along an elliptical shape inclined so as to be obliquely downward from the direction opposite to the traveling direction of the plate compactor and obliquely upward in the traveling direction, and above the elliptical shape, in the same direction as the traveling direction of the plate compactor. A vibrating method for a plate compactor, characterized in that the plate is circulated in a rotation direction opposite to the traveling direction on the lower side of the elliptical shape. 2. A driving eccentric shaft to which rotational power of a driving source is transmitted and one or more driven eccentric shafts are supported by positioning the vibration isolating member on the lower side with one of said driven eccentric shafts. In a vibration generator of a plate compactor, which is rotatably connected to a drive eccentric shaft via a transmission mechanism in a direction opposite to each other and rotates each of the eccentric shafts to apply vibration to a plate, The trajectory of the end point of the force vector starting from the center of gravity acting on the center of gravity of the lower weight is an elliptical shape in which the major axis is inclined obliquely downward from the direction opposite to the traveling direction of the plate compactor and obliquely upward in the traveling direction. A vibrating system in which the circulation direction is the same as the traveling direction of the plate compactor on the upper side of the elliptical shape and opposite to the traveling direction on the lower side of the elliptical shape To prepare A vibrating device for a plate compactor, comprising: 3. The drive eccentric shaft and the driven eccentric shaft rotating in the opposite direction to each other have different eccentric moments, and the direction of rotation of the eccentric shaft having the larger eccentric moment is determined by the direction of the eccentric shaft. 3. The vibration generator for a plate compactor according to claim 2, wherein the upper direction is set to be the same direction as the traveling direction of the plate compactor, and the lower side of the eccentric axis is set to be opposite to the traveling direction of the plate compactor. 4. Passing through the center of gravity of the weight below the vibration isolating member,
A line connecting the two eccentric shafts by a straight line that forms an angle at which the phases of the eccentric weights of the two eccentric shafts of the driving eccentric shaft and the driven eccentric shaft that rotates in the opposite direction coincides with each other is two. 4. The vibration generator for a plate compactor according to claim 3, wherein, when divided into line segments, the ratio of the eccentric moments of the two eccentric shafts is set to a ratio substantially equal to the length of a line segment farther from each other.