JP3252736B2 - Adjusting the spring characteristics of the buffer spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it possible to make the spring characteristics of a shock-absorbing spring interposed between two objects relatively moving parallel to each other and absorbing their relative displacement as close as possible to ideal characteristics. The present invention relates to a method for adjusting a spring characteristic that can be performed.

[0002]

2. Description of the Related Art In general, an elastic body may be interposed between two objects moving in parallel to each other for the purpose of absorbing the relative displacement and damping the vibration. In order to improve the vibration absorption up to large amplitude vibration, it is soft at small displacement,
It is desirable to use an elastic body having a non-linear spring characteristic that becomes hard at the time of large displacement.

In a TMD (tuned type dynamic vibration absorber) that reduces the amplitude of a specific natural frequency, the effect of reducing the vibration of the natural frequency is effectively exhibited from a small amplitude to a large amplitude. Therefore, it is necessary to use an elastic body having a linear spring characteristic having a constant spring constant regardless of the magnitude of the displacement.

[0004]

However, even if the elastic body is formed uniformly over its entire length to give a linear spring characteristic, a qualitative tendency is that as the displacement increases, the spring constant decreases. It is difficult to design and manufacture an elastic body exhibiting truly linear spring characteristics by compensating for this, and the development and manufacturing costs rise. In addition, it is difficult to design and manufacture an elastic body in conformity with a desired ideal non-linear spring characteristic when giving a non-linear spring characteristic, and it is also difficult to avoid an increase in development and manufacturing costs. This problem is particularly remarkable in the case of a rubber elastic body.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a spring characteristic of a shock-absorbing spring interposed between two objects which move relative to each other in parallel and absorbs their relative displacement. It is an object of the present invention to provide a method of adjusting spring characteristics that can approximate the ideal characteristics as easily as possible at low cost.

[0006]

In order to achieve the above object, a method for adjusting a spring characteristic of a shock-absorbing spring according to the present invention is provided between two objects which move relative to each other in parallel with each other and determine the relative displacement x between them. Spring characteristic Q = f of elastic body to absorb
(X) does not match the ideal ideal spring characteristic R = g (x), and the offset spring characteristic S =-(RQ) for offsetting the difference (RQ) between the spring characteristics is not satisfied. In the case of exhibiting non-linearity, a plurality of auxiliary springs exhibiting a linear characteristic with a constant spring constant are arranged between the two objects and combined, and the composite spring characteristics of the composite spring as a whole are approximated to the ideal spring characteristic R. A method of adjusting a spring characteristic of a shock-absorbing spring, wherein the auxiliary spring comprises: a primary auxiliary spring that functions over the entire range of an assumed displacement;
A secondary auxiliary spring partially functioning in a predetermined small displacement range where the primary auxiliary spring cannot fully approximate the spring characteristics, and the primary auxiliary spring is in a state where there is no relative displacement between the two objects. Then, an initial amount of strain δ ₁ is applied between the two objects so that the elastic restoring force acts at right angles to the relative displacement direction, and the object is mounted with a mounting width H ₁ and a spring constant ks ₁ .
s ₁ , the initial strain amount δ ₁ , and the mounting width H ₁ are set based on the following conditions (1) and (2), respectively, and the secondary auxiliary spring has a relative displacement between the two objects. Without
An initial amount of strain δ ₂ is applied between the two objects so that the elastic restoring force acts at right angles to the relative displacement direction, and the object is mounted with the mounting width H ₂ and the spring constant ks ₂ .
_{2. A} method for adjusting a spring characteristic, wherein the initial strain amount δ ₂ and the mounting width H ₂ are set based on the following conditions (3) and (4).

(1). The primary auxiliary spring, the length of time that the spring characteristic Q = F (x) and the ideal spring characteristic R = g (x) and is known both said object to displacement point x ₁ equal is parallel to relative displacement It is the L ₁ and natural length.

[0008] ^{_{L 1 = (x 1 2 +}} H 1 2) 1/2 (2). The extreme value of the relative displacement direction component force P _1x of the elastic restoring force P ₁ = −ks ₁ · δ of the auxiliary spring and its displacement point are as follows:
The spring characteristic Q = f (x) and the ideal spring characteristic R = g (x)
And a first-order canceling spring characteristic S ₁ = − (RQ)
Known extremum and its displacement point x ₂ (0 <x ₂ <x ₁ )
To match.

[0009] _{P 1x = -P 1 · {x} / (x 2 + H 1 2)
^1/2 ｝ (3). The secondary auxiliary spring is in a predetermined small displacement range where the primary correction spring characteristic Q ₁ = F ₁ (x) corrected by the primary auxiliary spring is to be further approximated to the ideal spring characteristic R = g (x). the length L ₂ when the both objects to the maximum displacement point x ₃ is parallel to relative displacement and natural length.

[0010] ^{_{L 2 = (x 3 2 +}} H 2 2) 1/2 (4). Elastic restoring force of the secondary auxiliary spring P ₂ = −ks _2.
The extreme value of the relative displacement direction component force P _2x of δ and its displacement point offset the difference between the primary correction spring characteristic Q ₁ = f ₁ (x) and the ideal spring characteristic R = g (x) 2 Next offset spring characteristic S
₂ = - to match the (R-Q ₁₎ of known obtained from extreme value and its displacement point _{x 4 (0 <x 4 <} x 3).

[0011] _{P 2x = -P 2 · {x} / (x 2 + H 2 2)
^To explain the operation of the present invention, when the spring characteristic Q = f (x) of the buffer spring does not match the ideal spring characteristic R = g (x), the spring characteristic Q of the buffer spring and the ideal spring Characteristic R
By attaching an auxiliary spring that can cancel out the difference (R−Q) as much as possible between the two objects and combining it with the buffer spring, the composite spring characteristics of the composite spring as a whole can be changed to the ideal spring characteristic R. Can be matched as far as possible. At this time, if the canceling spring characteristic S =-(RQ) for canceling the difference (RQ) exhibits an upwardly convex or downwardly convex nonlinearity, this is directly converted by a linear spring having a constant spring constant. Cannot be offset. Therefore, a primary auxiliary spring and a secondary auxiliary spring having linear spring characteristics
Initial strain amounts δ ₁ , δ ₂ are respectively provided between two objects in a direction orthogonal to the relative displacement direction, and the primary and secondary auxiliary springs are inclined in accordance with the relative displacement x. The above-mentioned spring characteristic difference (RQ) is canceled by the component forces P _1x and P _2x in the relative displacement directions of the elastic restoring forces P ₁ and P ₂ of the secondary and secondary auxiliary springs. Here, it is assumed that the secondary auxiliary spring further corrects a region of a predetermined small displacement portion which cannot be completely corrected by the primary auxiliary spring.

That is, the primary, acting as the canceling force,
The component forces P _1x and P _2x in the relative displacement direction of the secondary auxiliary spring are sin
By giving a non-linearity based on a curve, when there is no relative displacement, the component force P in the relative displacement direction as a canceling force is used.
_1x and _P2x are not generated.

The primary auxiliary spring has a spring characteristic Q = f (x) and an ideal spring characteristic R = g (x) of a known buffer spring.
From, calculates the displacement point x ₁ which they intersect, primary auxiliary spring in the displacement point x ₁ determines its length L ₁ such that the natural length, the relative displacement in the displacement point x ₁ The component force in the direction is set to zero. Further, based on the known spring characteristic Q = f (x) and the ideal spring characteristic R = g (x), the difference (R−
The extreme value of the primary canceling spring characteristic S = − (RQ) that cancels out Q) and its displacement point x ₂ (0 <x ₂ <x ₁ ) are calculated, and the extreme value and its displacement point x ₂ are calculated. to thereby match the extreme displacement point of the relative displacement direction of the component force P _1x, the initial strain amount [delta] _1, the attachment width H _1, determined by calculating the inverse, respectively and a spring constant ks _1, a buffer spring The primary correction spring characteristic Q ₁ = f ₁ (x) in a state of being combined with the primary auxiliary spring is made as close as possible to the ideal spring characteristic.

The secondary auxiliary spring functions in an area of a small displacement portion which cannot be completely corrected by the primary auxiliary spring, and a portion which is still shifted in the primary correction spring characteristic is set in the same manner as the primary auxiliary spring. And partially correct it.

That is, the primary correction spring characteristic Q ₁ = F
To ₁ further ideal spring characteristics R = g the length of the second auxiliary spring when displaced to the maximum displacement point x ₃ in a predetermined small displacement region desired to be approximated to (x) L ₂ (x) to its natural length .
Further, based on the known primary correction spring characteristic Q ₁ = f ₁ (x) and the ideal spring characteristic R = g (x), the difference (R−Q
Secondary canceling spring characteristic S ₂ = − (R−Q ₁ ) to cancel ₁ )
And its displacement point x ₄ (0 <x ₄ <x ₃ ) are calculated, and the extreme value and its displacement point x ₄ are calculated with the extreme value of the component force P _{2x in} the relative displacement direction of the secondary auxiliary spring. The initial displacement amount δ ₂ , the mounting width H ₂ , and the spring constant ks ₂ are calculated in reverse to obtain the initial strain amount δ ₂ , and the buffer spring is combined with the primary auxiliary spring and the secondary auxiliary spring. The final composite spring characteristics in the closed state are made as close as possible to the ideal spring characteristics.

Therefore, as described above, in the spring characteristic adjusting method of the present invention, the spring characteristic of the buffer spring interposed between the two objects that move relatively in parallel to each other and absorbs the relative displacement between them is linear. Using primary and secondary auxiliary springs having spring characteristics, it is possible to approximate the ideal characteristics as easily as possible at low cost.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a TMD (tuning type dynamic vibration absorber).
FIG. 2 shows a schematic configuration of an embodiment in which a shock absorbing spring device adjusted by the spring characteristic adjusting method according to the present invention is mounted on the TMD of the vibration isolating table provided with. FIGS. 5A and 5B are enlarged explanatory views showing an operation state of a main part in an exaggerated manner, in which FIG.

As shown in FIGS. 1 and 2, the TMD 1 includes an additional mass 4 mounted on the upper surface of a vibration isolation table 6 via a buffer spring device 2, a reaction force receiving member 3 also fixed on the upper surface,
A damper 5 is provided between the reaction force receiving member 5 and the additional mass 4 to attenuate vibration.

The shock absorbing spring device 2 is interposed between an additional mass 4 as two objects which move relatively in parallel to each other and a vibration isolator 6, and includes a main shock absorbing spring 8, a primary auxiliary spring 10, and a secondary auxiliary spring 11. And are combined. The main buffer spring 8 is an elastic body formed by sequentially laminating a rubber plate 8a and a steel plate 8b and uniformly forming it over its entire length, and is capable of supporting the load of the additional mass 4 and being horizontally displaceable. However, the vertical subsidence caused by the horizontal displacement hardly occurs and is negligible.

Here, assuming that the elastic restoring force of the main shock-absorbing spring 8 is Q and its spring characteristics can be expressed by Q = f (x), the main spring 8 is connected to the rubber plate over its entire length as described above. As shown in FIG. 3, the spring characteristic Q = f (x) shows an upwardly convex non-linearity because the steel plate and the steel plate are uniformly formed.
It is hard with small displacement and soft with large displacement.

However, as described above, in order for the natural vibration of the vibration isolation table 4 to be favorably absorbed by the TMD 1 from a small amplitude to a large amplitude, the spring characteristics of the buffer spring device 2 must be elastically restored with respect to the displacement. It is desirable to exhibit a linear characteristic in which the force changes linearly, and the ideal ideal spring characteristic R = g
(X) is preferably a linear characteristic as shown in FIG.

Therefore, the main buffer spring 8 and the primary auxiliary spring 10
In order to make the composite spring characteristic of the buffer spring device 2 composed of the primary and secondary auxiliary springs 11 close to the ideal spring characteristic R, the primary and secondary auxiliary springs 10 and 11 make the spring characteristic Q of the main buffer spring 8. It is necessary to compensate for the difference (R−Q) between the difference and the ideal spring characteristic R. That is, the primary and secondary auxiliary springs 10 and 11 create a canceling spring characteristic S =-(RQ) exhibiting a downwardly convex non-linearity that can cancel the difference (RQ) of the spring characteristics. If produced, the composite spring characteristic T of the buffer spring device 2 can be matched with the ideal spring characteristic R.

Therefore, in the present embodiment, the primary auxiliary spring 10 and the secondary auxiliary spring 11 are set as follows and combined with the main buffer spring 8, and the composite spring characteristic in the horizontal direction in the composite state is shown. T is made as close as possible to the ideal spring characteristic R.

That is, a coil spring having a linear characteristic is used for the primary auxiliary spring 10 and the secondary auxiliary spring 11, and the vibration damping table 6 and the additional mass 4 are connected to each other when the additional mass 4 is not horizontally displaced. Are disposed along the vertical direction, that is, at right angles to the direction of relative displacement.

First, the primary auxiliary spring 10 will be described in detail.

As shown in FIG. 2B, the primary auxiliary spring 1
The initial vibration amount (length) δ ₁ is given to 0, and the vibration isolation table 6 and the lower portion of the additional mass 4 are pin-coupled to each other via a universal joint or the like with a mounting width H ₁ , and the additional mass 4 is subjected to vibration isolation. When it is displaced horizontally relative to the table 6, a horizontal component P _1x of the elastic restoring force P ₁ of the primary auxiliary spring 10 acts on the additional mass 4. Further, here, the spring characteristic Q of the main buffer spring 8 is higher than the ideal spring characteristic R, and the horizontal component force P _1x of the primary auxiliary spring 10 is the elastic restoring force Q of the main buffer spring 8. It is necessary to act in the opposite direction so as to cancel each other. For this reason, the initial strain amount δ ₁ of the primary auxiliary spring 10 is given as a compression amount.

That is, the angle of the primary auxiliary spring 10 inclined according to the horizontal displacement amount x of the additional mass 4 from the vertical direction is θ
If it is set to ₁ , the horizontal component force P _{1x of the} primary auxiliary spring 10 shown in the following equation (1) acts on the additional mass 4 as a canceling force of the elastic restoring force Q of the main buffer spring 8. The spring characteristic of the canceling force is a downwardly convex non-linear characteristic based on a sin curve.

P _1x = −P ₁ sin θ ₁ = −ks ₁ · δ ₁ · sin θ ₁ (1) Also, the distortion amount δ ₁ is δ = δ ₁ + H ₁ − (x ² + H ₁ ² ) ^{1 / 2} ... (2), the elastic restoring force P ₁ = k of the primary auxiliary spring 10
s ₁ · δ is P ₁ = −ks ₁ · {δ ₁ + H _1- (x ² + H ₁ ² ) ^1/2 } (3), and sin θ ₁ is sin θ ₁ = x / (x ² + H ₁ ² ) ^1/2 (4) Therefore, the relative displacement direction component force P _1x acting as the canceling force is P _1x = −ks ₁ · ｛δ ₁ + H ₁ − (x ² + H ₁ ² ) ^1/2 ｝ · {x / (x ² + H ₁ ² ) ^1/2 } (5) can be expressed as a functional expression (5) of relative displacement x, and the expression (5) is Ks ₁ , δ ₁ , and H ₁ may be set so as to be as close as possible to the canceling spring characteristic S = − (Q−R).

[0029] Here, the relative displacement direction of the component force of the spring characteristic Q = F (x) and the ideal spring characteristic R = g (x) in the displacement points x ₁ and coincides primary auxiliary spring 10 0, i.e. δ since it is necessary to ₁ = 0, _{δ 1} in the formula (2) with x = x ₁
= 0 and ^{_{when, δ 1 = (x 1 2}} + H 1 2) 1/2 -H 1 ......... (6) is obtained, the initial strain of the auxiliary spring (length) can be seen. When shown by substituting the equation (6) into equation _{(5), P 1x = -ks} 1 · {(x 1 2 + H 1 2) 1/2 - (x 2 + H 1 2) 1/2}・ {X / (x ² + H ₁ ² ) ^1/2 } (7) Here, based on the condition that both extreme values (in this case, minimum values) of the relative movement direction component force P _1x and the canceling spring characteristic S = − (Q−R) are matched, a known S is used.
= − (Q−R) to its extreme value (S _min ) and its displacement point x
Seeking and _2, the displacement point x ₂ Substituting the partial differential equation of the equation (7) (the following formulas (8)), since the value is 0, the H ₁ is the following formula (9) Obtained as shown.

[0030]

(Equation 1)

[0031]

(Equation 2)

By transforming equation (8), the spring constant ks
_{Since 1} can be expressed as shown in the following equation (10), the spring constant ks ₁ can be obtained by substituting the already obtained x ₂ , H ₁ , and the extreme value (S _min ) of S, respectively.

[0033]

(Equation 3)

Next, the secondary auxiliary spring 11 will be described in detail. This secondary auxiliary spring 11 has a predetermined small displacement range 0 ≦ x ≦ x
₃ partially functions, and basically sets the same as in the case of the primary auxiliary spring 10. However, here, as described above, the extreme values are made to coincide with each other so that the primary correction spring characteristic Q1 when crossed and the ideal spring characteristics R, than its displacement point x ₂ of intersection be adapted to further correct the spring characteristics not completely corrected remain in the area of the small displacement portion, x ₃ = x ₂
It has become.

That is, the secondary auxiliary spring 11 is given an initial amount of strain (length) δ ₂ , and is pin-connected to the vibration isolating table 6 and the lower portion of the additional mass 4 with the mounting width H ₂ , respectively. Is horizontally displaced relative to the anti-vibration table 6, the horizontal component P _2x of the elastic restoring force P ₂ of the secondary auxiliary spring 11 acts on the additional mass 4. Further, where one supplementary spring characteristics in a state in which correction in the primary auxiliary spring 10 is Q ₁ is FIG. 3 (a), it exceeds still than ideal spring characteristic R in the small displacement region, as shown in (b) Assuming a case, an example will be described in which the initial distortion amount δ ₂ of the secondary auxiliary spring 11 is given as a compression amount. Note that FIG. 3B shows 0 ≦ x in FIG.
The range of ≦ x ₂ (= x ₃ ) is shown in an enlarged manner. .

Here, the angle from the vertical direction of the secondary auxiliary spring 11 inclined according to the horizontal displacement amount x of the additional mass 4 is represented by θ.
Assuming that ₂ , the additional mass 4 includes the horizontal component force P _{2x of the} secondary auxiliary spring 11 shown in the following equation (11).
It acts as a secondary canceling force against the elastic restoring force under the primary corrected spring characteristic Q ₁ corrected by 0. The spring characteristic of this secondary canceling force is based on a sin curve. The secondary canceling force matches the secondary canceling spring characteristic S ₂ = − (R−Q ₁ ) of the difference between the primary correction spring characteristic Q ₁ and the ideal spring characteristic R. To do.

P _2x = −P ₂ sin θ ₂ = −ks ₂ · δ ₂ · sin θ ₂ (11) The distortion amount δ ₂ is δ = δ ₂ + H ₂ − (x ² + H ₂ ² ) ^{1 / 2} ... (12), the elastic restoring force P ₂ = k of the primary auxiliary spring 10
s ₂ · δ is P ₂ = −ks ₂ · {δ ₂ + H ₂ − (x ² + H ₂ ² ) ^1/2 } (13), and sin θ ₂ is sin θ ₂ = x / (x ² + H) ₂ ² ) ^1/2 (14) Therefore, the relative displacement direction component force P _1x acting as the canceling force is P _2x = −ks ₂ · ｛δ ₂ + H ₂ − (x ² + H ₂ ² ) ^1/2 ｝ · {x / (x ² + H ₂ ² ) ^1/2 } (15) can be expressed as a functional expression (15) of the relative displacement x, and the expression (15) cancels the above-mentioned offset. Spring characteristic S ₂ = − (R−Q
Ks ₂ , δ ₂ , and H ₂ may be set so as to be as close as possible to ₁ ).

Here, the displacement point x ₃ (= the displacement point where the spring characteristic Q ₁ = F ₁ (x) and the ideal spring characteristic R = g (x) coincide with each other.
x ₂ ), the component force in the relative displacement direction of the primary auxiliary spring 10 needs to be 0, that is, δ ₂ = 0. Therefore, if x = x ₃ and δ ₂ = 0 in the equation (2), δ ^{_{2 = (x 3 2 + H}} 2 2) 1/2 -H 2 ......... (16) is obtained, the initial strain of the auxiliary spring (length) can be seen. When shown by substituting the equation (16) into equation _{(15), P 2x = -ks} 2 · {(x 3 2 + H 2 2) 1/2 - (x 2 + H 2 2) 1/2}・ {X / (x ² + H ₂ ² ) ^1/2 } (17) Here, based on a condition that both extreme values (in this case, minimum values) of the relative moving direction component force P _2x and the canceling spring characteristic S ₂ = − (Q ₁ −R) are matched, a known S value is used. ₂ = - seeking (Q ₁ -R) from its extreme value (S _{2 min)} and the displacement point x _4, the formula the displacement point x ₄ (1
Substituting the partial differential equation (the following formulas (18)) of the 7), since the value is 0, H ₂ is obtained as shown in the following equation (19).

[0039]

(Equation 4)

[0040]

(Equation 5)

By transforming equation (18), the spring constant k
Since s ₂ can be expressed as shown in the following equation (20), the extreme values (S _{2 min} ) of x ₄ , H ₂ , and S2 which have already been obtained therefrom are obtained.
, The spring constant ks ₂ is obtained.

[0042]

(Equation 6)

As described above, various settings of the primary auxiliary spring 10 and the secondary auxiliary spring 11 can be determined. These primary and secondary auxiliary springs 10 and 11 are specifically described in, for example, FIG.
The configuration is as shown in FIG.

That is, the upper spring seat 16 and the lower spring seat 18 are integrally formed on the extensible upper rod 12 and the lower rod 14, which are fitted to each other so that the axes thereof are aligned with each other and are slidable, The upper and lower ends are engaged with these spring seats 16 and 18 to provide a coil spring 20 having excellent linear characteristics. At the ends of the upper and lower rods 12, 14, mounting holes 22 for pin connection are provided.
24, and the dimensions of each member are designed such that the span L of the upper and lower mounting holes 22 and 24 is H ₁ + δ ₁ or H ₂ + δ ₂ calculated as described above with the coil spring 20 having a natural length. The spring constant of the coil spring 20 to be used of course to ks ₁ or ks _2. These primary and secondary auxiliary springs 10 and 11 are vertically attached to the additional mass 4 and the vibration isolating table 6 in a state where they are not displaced in the horizontal direction. At this time, the span of the engaging pin for attaching the auxiliary spring provided on the additional mass 4 side and the vibration isolation table 6 side is set to H ₁ and H ₂ , and the primary and secondary auxiliary springs 10 and 11 are set. The primary and secondary auxiliary springs 10, 11 generate initial compressive strain amounts (lengths) δ ₁ , δ ₂ in the coil springs 20 in a state where the first and second auxiliary springs 10 and 11 are attached. In particular, 2
In the case of the next auxiliary spring 11, after being displaced to the displacement x ₃ (= x ₂ ) and extending to the natural length, the spring 20 and the upper spring seat 16 are separated from each other so that no tensile force acts. Should be removed.

Therefore, as described above, according to the spring characteristic adjusting method of the cushioning spring device 2, the spring of the main cushioning spring 8 interposed between the additional mass 4 and the vibration isolator 6 which are relatively displaced horizontally. When the characteristic Q does not match the ideal spring characteristic R, the primary auxiliary spring 10 and the secondary auxiliary spring 1 exhibit linear spring characteristics in which the spring constant is constant regardless of displacement.
1 with a simple configuration in which they are vertically mounted between the additional mass 4 and the vibration isolation table 6 without horizontal displacement occurring between them, and the main damping spring 8 and the 1
Next, the composite spring characteristic T in a state where the secondary and secondary auxiliary springs 10 and 11 are combined can be made as close as possible to the desired ideal spring characteristic R.

Further, if the primary auxiliary spring 10 and the secondary auxiliary spring 11 are manufactured by using a coil spring which can be easily designed and manufactured to a predetermined spring constant and has excellent linear spring characteristics, it is inexpensive and highly accurate. Adjustment of the spring characteristics can be performed.

In the above description, the main buffer spring 8
The spring characteristic Q of the main shock absorber 8 is higher than the ideal spring characteristic R. On the contrary, if the spring characteristic Q of the main buffer spring 8 is lower than the ideal spring characteristic R, Auxiliary spring 1 for applying a pulling force to table 6
0 and 11 may be configured.

More specifically, for example, as shown in FIG.
And a lower portion of the upper rod 12 is inserted into a lower portion of the upper rod 12 through an insertion hole 28 opened in an upper wall of the case 26, and a lower spring seat 18 is integrally provided at a lower end of the upper rod 12. The casing 26 is slid along the inner wall surface of the casing 26 so that the upper wall of the casing 26 is used as the upper spring seat 16 so that the two spring seats 16, 1
The coil spring 20 is provided by integrally fixing the upper and lower ends between the coil springs 8.

Then, as in the case of FIG. 4A, the upper and lower mounting holes 22 and 2 are set with the coil spring 20 having the natural length.
The spans L ₁ and L ₂ of _No. 4 are calculated as H ₁ + δ ₁ as described above.
Alternatively, the dimensions of each member are designed to be H ₂ + δ ₂ . The spring constant of the coil spring 20 used is naturally set to ks ₁ and ks ₂ . The auxiliary springs 10 and 11 are vertically attached to the additional mass 4 and the building 6 in a state where no horizontal displacement occurs in the additional mass 4 and the building 6. At this time, the spans of the auxiliary pins for attaching the auxiliary springs provided on the additional mass 4 side and the vibration isolation table 6 side are set to H ₁ and H ₂ , and the auxiliary springs 10 and 11 are attached. The coil springs 20 of the auxiliary springs 10 and 11 cause an initial elongation strain (length) δ ₁ to δ ₂ .

In the illustrated example, the case where the spring characteristic adjusting method of the present invention is applied to the vibration isolating table provided with the TMD is illustrated. However, the spring characteristic adjusting method is not limited to this, and the spring characteristic adjusting method is not limited thereto. The present invention is applicable to all types of cushioning spring devices provided between two displaced objects. That is, the relative displacement direction may be, for example, a vertical direction, and the main buffer spring 8 may be an elastic body such as an air spring.

[0051]

As described above in detail in the embodiments,
According to the present invention, when the spring characteristic Q of the main buffer spring interposed between the two objects relatively displaced in parallel does not match the ideal spring characteristic R, the spring constant is constant regardless of the displacement. A simple arrangement in which a primary auxiliary spring and a secondary auxiliary spring exhibiting linear spring characteristics are mounted between two objects at right angles to the direction of relative displacement thereof without horizontal displacement occurring between them. With such a configuration, it is possible to approximate the composite spring characteristic in a state in which the main buffer spring and the primary and secondary auxiliary springs are combined to the desired ideal spring characteristic R as much as possible. In addition, if the auxiliary spring is manufactured using a coil spring that can be easily designed and manufactured to have a predetermined spring constant and has excellent linear spring characteristics, the spring characteristics can be adjusted at low cost and with high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration in a case where a buffer spring device adjusted by a spring characteristic adjusting method according to the present invention is applied to a TMD of a vibration isolation table.

FIGS. 2A and 2B are enlarged explanatory views showing an operation state of a main part in FIG. 1, in which FIG. 2A shows a small displacement, and FIG. 2B shows a large displacement.

[3] FIG. (A) is a graph conceptually showing a relationship between the spring characteristic Q of the buffer spring and that ideal spring characteristics R, and a primary offset spring characteristics of S ₁ to offset the difference, the FIG. 2B is an enlarged view showing the range of 0 ≦ x ≦ x ₂ in FIG.

4A and 4B are diagrams showing a specific configuration example of an auxiliary spring. FIG. 4A shows an auxiliary spring when an initial distortion amount is applied to a compression side, and FIG. It shows an auxiliary spring when giving.

[Explanation of symbols]

 Reference Signs List 2 buffer spring device 4 additional mass 6 anti-vibration table 8 main buffer spring 10 primary auxiliary spring 11 secondary auxiliary spring 12 upper rod 14 lower rod 16 upper spring seat 18 lower spring seat 20 coil spring 22, 24 mounting hole 26 casing 28 Insertion hole

Claims (1)

(57) [Claims] A spring characteristic Q = f (x) of an elastic body which is interposed between two objects relatively moving in parallel with each other and absorbs their relative displacement x is an ideal ideal spring characteristic R
= G (x) does not match, and the difference between the spring characteristics (R−Q)
When the canceling spring characteristic S = − (RQ) for canceling the non-linearity exhibits non-linearity, a plurality of auxiliary springs exhibiting a linear characteristic with a constant spring constant are arranged between the two objects and combined.
A method of adjusting a spring characteristic of a buffer spring that approximates the composite spring characteristic of the composite spring as a whole to the ideal spring characteristic R, wherein the auxiliary spring functions as a primary auxiliary spring that functions over the entire range of an assumed displacement. A secondary auxiliary spring that partially functions in a predetermined small displacement range in which the primary auxiliary spring cannot fully approximate the spring characteristics. The primary auxiliary spring is in a state where no relative displacement occurs between the two objects. An initial strain amount δ ₁ is applied between the two objects so that the elastic restoring force acts at right angles to the relative displacement direction, and the object is mounted with a mounting width H ₁ and a spring constant ks ₁ .
s ₁ , the initial strain amount δ ₁ , and the mounting width H ₁ are set based on the following conditions (1) and (2), respectively, and the secondary auxiliary spring has a relative displacement between the two objects. Without
An initial amount of strain δ ₂ is applied between the two objects so that the elastic restoring force acts at right angles to the relative displacement direction, and the object is mounted with the mounting width H ₂ and the spring constant ks ₂ .
_{2. A} method for adjusting a spring characteristic, wherein the initial strain amount δ ₂ and the mounting width H ₂ are set based on the following conditions (3) and (4). (1). The primary auxiliary spring has the spring characteristic Q = F (x)
An ideal spring characteristic R = g (x) and the length L ₁ to a natural length when the both objects is parallel to the relative displacement to a known displacement point x ₁ equal. ^{_{L 1 = (x 1 2 +}} H 1 2) 1/2 (2). The extreme value of the component force P _{1x in} the relative displacement direction of the elastic restoring force P ₁ = −ks ₁ · δ of the auxiliary spring and its displacement point are determined by the spring characteristic Q = f (x) and the ideal spring characteristic R = g.
(X) and a first-order canceling spring characteristic S ₁ = − (R
-Q) and its displacement point x ₂ (0 <x ₂ <
x ₁ ). _{P 1x = -P 1 · {x} / (x 2 + H 1 2) 1/2} (3). The secondary auxiliary spring is in a predetermined small displacement range where the primary correction spring characteristic Q ₁ = F ₁ (x) corrected by the primary auxiliary spring is to be further approximated to the ideal spring characteristic R = g (x). the length L ₂ when the both objects to the maximum displacement point x ₃ is parallel to relative displacement and natural length. ^{_{L 2 = (x 3 2 +}} H 2 2) 1/2 (4). Elastic restoring force of the secondary auxiliary spring P ₂ = −ks _2.
The extreme value of the relative displacement direction component force P _2x of δ and its displacement point offset the difference between the primary correction spring characteristic Q ₁ = f ₁ (x) and the ideal spring characteristic R = g (x) 2 Next offset spring characteristic S
₂ = - to match the (R-Q ₁₎ of known obtained from extreme value and its displacement point _{x 4 (0 <x 4 <} x 3). P _2x = −P ₂ · {x / (x ² + H ₂ ² ) ^1/2 }